Basic Procedures

A physician’s diagnostic and therapeutic tool kit must include a variety of basic procedures that can be performed in the outpatient setting. These procedures include emergency intervention of the airway; drainage of fluid from the abdomen, joints, and spinal canal; and incision and drainage of abscesses. Although these procedures may be of reduced complexity, there are still inherent risks associated with invasive procedures, and these risks must be reduced through consistent aseptic and procedural techniques.

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Editorial responsibility: Stanley Oiseth, Lindsay Jones, Evelin Maza

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Cricothyroidotomy/Tracheostomy

Definitions

  • Cricothyroidotomy: surgical creation of an artificial opening on the cricothyroid membrane
  • Tracheotomy: surgical creation of an artificial opening on the anterior wall of the trachea Trachea The trachea is a tubular structure that forms part of the lower respiratory tract. The trachea is continuous superiorly with the larynx and inferiorly becomes the bronchial tree within the lungs. The trachea consists of a support frame of semicircular, or C-shaped, rings made out of hyaline cartilage and reinforced by collagenous connective tissue. Trachea
    • Used synonymously with the term tracheostomy
    • Tracheotomy technically refers to an incision into the trachea Trachea The trachea is a tubular structure that forms part of the lower respiratory tract. The trachea is continuous superiorly with the larynx and inferiorly becomes the bronchial tree within the lungs. The trachea consists of a support frame of semicircular, or C-shaped, rings made out of hyaline cartilage and reinforced by collagenous connective tissue. Trachea, whereas tracheostomy refers to the placement of a cannula into that opening.

Therapeutic goal

Achievement of a secure airway:

  • Usually, when the pharynx Pharynx The pharynx is a component of the digestive system that lies posterior to the nasal cavity, oral cavity, and larynx. The pharynx can be divided into the oropharynx, nasopharynx, and laryngopharynx. Pharyngeal muscles play an integral role in vital processes such as breathing, swallowing, and speaking. Pharynx and larynx Larynx The larynx, also commonly called the voice box, is a cylindrical space located in the neck at the level of the C3-C6 vertebrae. The major structures forming the framework of the larynx are the thyroid cartilage, cricoid cartilage, and epiglottis. The larynx serves to produce sound (phonation), conducts air to the trachea, and prevents large molecules from reaching the lungs. Larynx need to be bypassed (e.g., obstruction)
  • To provide easy access to the lower airways for bronchial aspiration in the case of tracheostomy

Indications

Cricothyroidotomy (critical care):

  • Maxillofacial trauma
  • Facial fractures

Tracheostomy:

  • Emergent:
    • Acute obstruction (failed endotracheal intubation)
    • Laryngeal trauma
    • Postcricothyroidotomy
  • Chronic:
    • Functional obstruction of the upper airway (e.g., carcinoma of larynx Larynx The larynx, also commonly called the voice box, is a cylindrical space located in the neck at the level of the C3-C6 vertebrae. The major structures forming the framework of the larynx are the thyroid cartilage, cricoid cartilage, and epiglottis. The larynx serves to produce sound (phonation), conducts air to the trachea, and prevents large molecules from reaching the lungs. Larynx)
    • Long-term ventilatory support 
    • Chronic aspiration

Contraindications

Absolute:

  • Intact nonsurgical airway
  • Subglottic obstruction
  • Thyroid/cricoid cartilage Cartilage Cartilage is a type of connective tissue derived from embryonic mesenchyme that is responsible for structural support, resilience, and the smoothness of physical actions. Perichondrium (connective tissue membrane surrounding cartilage) compensates for the absence of vasculature in cartilage by providing nutrition and support. Cartilage fracture Fracture A fracture is a disruption of the cortex of any bone and periosteum and is commonly due to mechanical stress after an injury or accident. Open fractures due to trauma can be a medical emergency. Fractures are frequently associated with automobile accidents, workplace injuries, and trauma. Overview of Bone Fractures
  • Individual < 8 years old

Relative:

  • Massive neck swelling or hematoma
  • Cervical trauma

Procedure

Both procedures can be performed at the bedside; however, it is preferable for tracheotomies to be performed in the OR.

Preoperative preparation:

  • In an emergency cricothyroidotomy, some of the steps below may be skipped. 
  • Explain the procedure to the individual and obtain informed consent, if possible.
  • Place individual in the supine position, with the neck extended, unless contraindicated, with the chin aligned with the midline. 
  • Administer preoperative antibiotics at least 30 minutes before incision, if possible. 
  • If possible, sedate and intubate the individual.
  • Identify the thyroid and cricoid cartilages.
  • Plan the orientation of the incision.
  • Wash the site of the incision with a skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Structure and Function of the Skin-sterilizing solution and cover with sterile drapes.
  • Continuous monitoring:
    • HR
    • Blood pressure
    • Oxygen saturation 
    • ECG ECG An electrocardiogram (ECG) is a graphic representation of the electrical activity of the heart plotted against time. Adhesive electrodes are affixed to the skin surface allowing measurement of cardiac impulses from many angles. The ECG provides 3-dimensional information about the conduction system of the heart, the myocardium, and other cardiac structures. Normal Electrocardiogram (ECG) rhythm monitor
  • In either the ED or OR, the operator should don adequate PPE.

Cricothyroidotomy:

  1. Local anesthetic (1% lidocaine) is infiltrated into the proposed incision site. 
  2. The thyroid cartilage Cartilage Cartilage is a type of connective tissue derived from embryonic mesenchyme that is responsible for structural support, resilience, and the smoothness of physical actions. Perichondrium (connective tissue membrane surrounding cartilage) compensates for the absence of vasculature in cartilage by providing nutrition and support. Cartilage is immobilized with the nondominant hand Hand The hand constitutes the distal part of the upper limb and provides the fine, precise movements needed in activities of daily living. It consists of 5 metacarpal bones and 14 phalanges, as well as numerous muscles innervated by the median and ulnar nerves. Hand, and the skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Structure and Function of the Skin is held under tension over the cricothyroid membrane.
  3. A 3-cm vertical incision is made on the midline, over the cricoid membrane. Horizontal incision is avoided, since in emergency situations, the incision could be extended too far laterally and the jugular veins Veins Veins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins could be injured.
  4. Manual retraction of the edges of the incision is performed with the nondominant hand Hand The hand constitutes the distal part of the upper limb and provides the fine, precise movements needed in activities of daily living. It consists of 5 metacarpal bones and 14 phalanges, as well as numerous muscles innervated by the median and ulnar nerves. Hand.
  5. Subcutaneous tissue and strap muscles are dissected at the midline to expose the thyroid and cricoid cartilages and the cricoid membrane. 
  6. A low, 1–2-cm incision is made on the cricoid membrane.
    • The incision is made as low as possible to avoid vocal cord damage.
    • Note: Once the airway is accessed, be on guard for sputum and secretions when the individual tries to exhale. 
  7. Once the incision is made, the handle of the scalpel is introduced into the incision and twisted 90 degrees to expand the incision.
    • The index finger of the nondominant hand Hand The hand constitutes the distal part of the upper limb and provides the fine, precise movements needed in activities of daily living. It consists of 5 metacarpal bones and 14 phalanges, as well as numerous muscles innervated by the median and ulnar nerves. Hand is used to keep the incision open while the scalpel is flipped.
    • The scalpel is maintained in the opening to maintain patency and facilitate passage of a cannula.
  8. An endotracheal or tracheostomy tube is inserted into the airway through the incision, using the scalpel handle as a retractor and guide. 
  9. The cuff of the tube is inflated. 

Tracheostomy (Seldinger-type technique):

  1. An incision is made on the midline:
    • Horizontal: 1 cm below the cricoid cartilage Cartilage Cartilage is a type of connective tissue derived from embryonic mesenchyme that is responsible for structural support, resilience, and the smoothness of physical actions. Perichondrium (connective tissue membrane surrounding cartilage) compensates for the absence of vasculature in cartilage by providing nutrition and support. Cartilage
    • Vertical: from the inferior aspect of the cricoid cartilage Cartilage Cartilage is a type of connective tissue derived from embryonic mesenchyme that is responsible for structural support, resilience, and the smoothness of physical actions. Perichondrium (connective tissue membrane surrounding cartilage) compensates for the absence of vasculature in cartilage by providing nutrition and support. Cartilage, extending 2–3 cm caudally
  2. Subcutaneous tissue and strap muscles along the midline are dissected to expose the trachea Trachea The trachea is a tubular structure that forms part of the lower respiratory tract. The trachea is continuous superiorly with the larynx and inferiorly becomes the bronchial tree within the lungs. The trachea consists of a support frame of semicircular, or C-shaped, rings made out of hyaline cartilage and reinforced by collagenous connective tissue. Trachea and thyroid gland Thyroid gland The thyroid gland is one of the largest endocrine glands in the human body. The thyroid gland is a highly vascular, brownish-red gland located in the visceral compartment of the anterior region of the neck. Thyroid Gland.
  3. The thyroid isthmus is retracted away or divided.
  4. An incision is made between the 2nd and 3rd tracheal rings and is dilated.
    • The surgeon must communicate with the anesthesiologist before accessing the airway.
    • The existing endotracheal tube will be manipulated to allow passage of the tracheostomy tube. 
  5. The endotracheal tube is elevated to just above the tracheotomy.
  6. The tracheostomy tube is placed through the opening in the trachea Trachea The trachea is a tubular structure that forms part of the lower respiratory tract. The trachea is continuous superiorly with the larynx and inferiorly becomes the bronchial tree within the lungs. The trachea consists of a support frame of semicircular, or C-shaped, rings made out of hyaline cartilage and reinforced by collagenous connective tissue. Trachea and the cuff is inflated. 
  7. The tube is connected to the mechanical ventilator. 

Right after the airway is secured:

  • The endotracheal tube is extracted, if one was present, and the tracheotomy tube is secured using sutures. 
  • The airway mask bag unit is connected to the tube and the individual is ventilated with 100% O2
  • Both sides are auscultated to ensure placement of the tube above the carina.
  • Arterial blood gases and a chest x-ray should be requested.

Complications

  • Intraoperative and postoperative hemorrhage
  • Improper placement with asphyxia
  • Accidental decannulation:
    • Individuals with altered mental status (e.g., delirium Delirium Delirium is a medical condition characterized by acute disturbances in attention and awareness. Symptoms may fluctuate during the course of a day and involve memory deficits and disorientation. Delirium) are at risk.
    • Temporary restraints may be used during the procedure.
  • Tube obstruction
  • Tracheoesophageal fistula Tracheoesophageal fistula Tracheoesophageal fistula is an abnormal connection between the trachea and esophagus. Esophageal Atresia and Tracheoesophageal Fistula
  • Displacement of the tracheotomy tube
  • Tracheal stenosis
  • Pneumothorax Pneumothorax A pneumothorax is a life-threatening condition in which air collects in the pleural space, causing partial or full collapse of the lung. A pneumothorax can be traumatic or spontaneous. Patients present with a sudden onset of sharp chest pain, dyspnea, and diminished breath sounds on exam. Pneumothorax/pneumomediastinum (rare)

Paracentesis

Definition

  • The evacuation of fluid within the peritoneal cavity via a needle and/or catheter for diagnostic and/or therapeutic purposes
  • Also known as abdominal tap

Therapeutic goals

  • Diagnosis of the causative disease process for peritoneal fluid accumulation
  • Temporary relief of symptoms caused by tense or chronic ascites Ascites Ascites is the pathologic accumulation of fluid within the peritoneal cavity that occurs due to an osmotic and/or hydrostatic pressure imbalance secondary to portal hypertension (cirrhosis, heart failure) or non-portal hypertension (hypoalbuminemia, malignancy, infection). Ascites:
    • Respiratory (e.g., dyspnea Dyspnea Dyspnea is the subjective sensation of breathing discomfort. Dyspnea is a normal manifestation of heavy physical or psychological exertion, but also may be caused by underlying conditions (both pulmonary and extrapulmonary). Dyspnea)
    • GI (e.g., diarrhea Diarrhea Diarrhea is defined as ≥ 3 watery or loose stools in a 24-hour period. There are a multitude of etiologies, which can be classified based on the underlying mechanism of disease. The duration of symptoms (acute or chronic) and characteristics of the stools (e.g., watery, bloody, steatorrheic, mucoid) can help guide further diagnostic evaluation. Diarrhea, early satiety)

Indications

  • New-onset ascites Ascites Ascites is the pathologic accumulation of fluid within the peritoneal cavity that occurs due to an osmotic and/or hydrostatic pressure imbalance secondary to portal hypertension (cirrhosis, heart failure) or non-portal hypertension (hypoalbuminemia, malignancy, infection). Ascites
  • Suspected malignant ascites Ascites Ascites is the pathologic accumulation of fluid within the peritoneal cavity that occurs due to an osmotic and/or hydrostatic pressure imbalance secondary to portal hypertension (cirrhosis, heart failure) or non-portal hypertension (hypoalbuminemia, malignancy, infection). Ascites
  • Suspected intraabdominal infection

Contraindications

Absolute:

  • Acute abdomen Acute Abdomen Acute abdomen, which is in many cases a surgical emergency, is the sudden onset of abdominal pain that may be caused by inflammation, infection, perforation, ischemia, or obstruction. The location of the pain, its characteristics, and associated symptoms (e.g., jaundice) are important tools that help narrow the differential diagnosis. Acute Abdomen
  • DIC DIC Disseminated intravascular coagulation (DIC) is a condition characterized by systemic bodywide activation of the coagulation cascade. This cascade results in both widespread microvascular thrombi contributing to multiple organ dysfunction and consumption of clotting factors and platelets, leading to hemorrhage. Disseminated Intravascular Coagulation

Relative:

  • Current bowel obstruction or severe bowel distention
  • Previous abdominal surgery (because of the likelihood of adhesions)
  • Anticoagulated individuals with no evidence of DIC DIC Disseminated intravascular coagulation (DIC) is a condition characterized by systemic bodywide activation of the coagulation cascade. This cascade results in both widespread microvascular thrombi contributing to multiple organ dysfunction and consumption of clotting factors and platelets, leading to hemorrhage. Disseminated Intravascular Coagulation
  • Pregnant individuals: requires ultrasound guidance

Procedure

Owing to its simplicity, the procedure can be performed at the bedside. 

Surface anatomy landmarks:

  • Umbilicus
  • Anterior superior iliac spine

Preoperative preparation:

  • Explain the procedure to the individual and obtain informed consent.
  • Individual is placed in the supine or lateral decubitus position.
  • The site for puncture is selected and marked:
    • Infraumbilical approach: 2 cm below the umbilicus
    • Lateral approach: point between lateral 3rd and middle 3rd of an imaginary line drawn between the umbilicus and the anterior superior iliac spine
      • Lateral to the rectus abdominis muscle
      • 2–4 cm superomedial from the anterior superior iliac spine
    • Avoid surgical scars because there may be adhesions underneath within the peritoneal cavity, increasing the risk of bowel injury
  • The site of the incision is washed with a skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Structure and Function of the Skin-sterilizing solution (povidone–iodine or chlorhexidine) and covered with sterile drapes.
  • Continuous monitoring:
    • HR
    • Blood pressure
  • Stomach Stomach The stomach is a muscular sac in the upper left portion of the abdomen that plays a critical role in digestion. The stomach develops from the foregut and connects the esophagus with the duodenum. Structurally, the stomach is C-shaped and forms a greater and lesser curvature and is divided grossly into regions: the cardia, fundus, body, and pylorus. Stomach decompression with nasogastric tube, if necessary.
  • Bladder decompression with Foley catheter. If necessary.

Technique:

  1. Local anesthetic (1% lidocaine) is infiltrated into the proposed puncture site.
  2. The needle (18- to 22-gauge) is inserted into the chosen site perpendicularly to the skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Structure and Function of the Skin (or at a 45-degree angle).
  3. The skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Structure and Function of the Skin is held under tension and the needle is advanced further until it reaches the peritoneal cavity.
    • While advancing, intermittent suction is applied.
    • The return of fluid in the syringe confirms entrance to the cavity. 
  4. 20–50 mL of fluid is collected for analysis.
  5. If the paracentesis is continued for therapeutic purposes, the needle is connected to IV tubing and to vacuum bottles or to a syringe for sequential aspiration.
  6. Extraction usually stops when 5 L of fluid has been collected. (Large-volume paracentesis has been associated with hypotension Hypotension Hypotension is defined as low blood pressure, specifically < 90/60 mm Hg, and is most commonly a physiologic response. Hypotension may be mild, serious, or life threatening, depending on the cause. Hypotension.) 
  7. The needle is extracted and the puncture site is covered with sterile gauze. (If the puncture site continues to leak after 5 minutes of pressure, it should be sutured).

After the procedure:

  • Vital signs should be monitored for 1 hour after puncture.
  • Individuals should be able to return to normal activities immediately.

Complications (rare)

  • Perforation of hollow viscus 
  • Lacerations of major vessels
  • Hematoma at puncture site
  • Introduction of infection
  • Ascitic fluid leak
  • Hypotension
  • Bladder perforation

Incision and Drainage of Superficial Abscesses

Definition

  • Incision and drainage (I&D) is the primary treatment of superficial skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Structure and Function of the Skin infections encompassing the procedure of incising and draining a superficial collection of purulent material in order to manage the lesion.
  • Pertains to abscesses found mostly on the skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Structure and Function of the Skin/ skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Structure and Function of the Skin structures

Therapeutic goals

  • Elimination of infectious focus
  • Reduction of inflammatory response
  • Restoration of normal anatomy

Indications

  • Most individuals with subcutaneous abscesses:
    • Antibiotics alone will not lead to complete resolution.
    • Incision and drainage of abscess contents facilitates clearance of purulent material, reduces edema Edema Edema is a condition in which excess serous fluid accumulates in the body cavity or interstitial space of connective tissues. Edema is a symptom observed in several medical conditions. It can be categorized into 2 types, namely, peripheral (in the extremities) and internal (in an organ or body cavity). Edema and pain Pain Pain has accompanied humans since they first existed, first lamented as the curse of existence and later understood as an adaptive mechanism that ensures survival. Pain is the most common symptomatic complaint and the main reason why people seek medical care. Physiology of Pain.
  • Remember: Perirectal and periareolar abscesses require prior consultation with surgery due to the increased risk of fistula formation.

Contraindications

  • Large or deeper abscess
  • Pulsatile mass close to the abscess
  • Proximity to important vessels or nerves
  • Presence of foreign body

Procedure

Owing to its simplicity, the procedure can be performed at the bedside or in an outpatient setting.

Preoperative preparation:

  • Explain the procedure to the individual and obtain informed consent.
  • Verify tetanus Tetanus Tetanus is a bacterial infection caused by Clostridium tetani, a gram-positive obligate anaerobic bacterium commonly found in soil that enters the body through a contaminated wound. C. tetani produces a neurotoxin that blocks the release of inhibitory neurotransmitters and causes prolonged tonic muscle contractions. Tetanus immunization.
  • The site of the abscess is identified and the incision is marked. 
  • The skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Structure and Function of the Skin is washed with a skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Structure and Function of the Skin-sterilizing solution and covered with sterile drapes.
  • The operator must don adequate PPE.

Technique:

  1. Local anesthetic (1% lidocaine) is infiltrated into the proposed incision site.
  2. An incision is made directly into the center of the abscess.
    • The incision is made parallel to the skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Structure and Function of the Skin lines of tension.
    • A curved hemostat can be used for blunt dissection.
  3. Once the abscess is punctured, it should immediately produce purulent material.
    • Sterile drapes or gauze should be immediately placed underneath the incision to collect the material as it comes out.
    • Some abscesses can have such large amounts of material that a kidney tray may be needed for collection. 
  4. Using both hands, the operator presses on the borders of the abscess to force its contents out.
    • This step should be done very cautiously to prevent pus from jetting out of the incision.
    • The limits of the abscess may be explored with curved hemostats or a gloved finger. 
  5. After the abscess has been completely evacuated, the wound should be generously irrigated with normal saline. 
  6. Packing is needed only for abscesses > 5 cm in diameter.
  7. The incision is covered with sterile gauze and adhesive.
  8. Closure is by secondary intention.

Postoperative care Postoperative care After any procedure performed in the operating room, all patients must undergo close observation at least in the recovery room. After larger procedures and for patients who require hospitalization, observation must continue on the surgical ward. The primary intent of this practice is the early detection of postoperative complications. Postoperative Care:

  • Follow-up visit in 2–3 days to remove packing
  • Antibiotics are prescribed for up to 7 days (antistreptococcal/antistaphylococcal).

Complications

  • Surgical-site infection
  • Pain at the incision site
  • Hemorrhage
  • Cellulitis Cellulitis Cellulitis is a common infection caused by bacteria that affects the dermis and subcutaneous tissue of the skin. It is frequently caused by Staphylococcus aureus and Streptococcus pyogenes. The skin infection presents as an erythematous and edematous area with warmth and tenderness. Cellulitis around the incision site

Lumbar Puncture

Definition

  • Removal of CSF from the spinal canal by means of a spinal needle, for diagnostic or therapeutic purposes 
  • Also known as a spinal tap

Indications

  • Diagnosis of:
    • Suspected CNS infection (e.g., meningitis Meningitis Meningitis is inflammation of the meninges, the protective membranes of the brain, and spinal cord. The causes of meningitis are varied, with the most common being bacterial or viral infection. The classic presentation of meningitis is a triad of fever, altered mental status, and nuchal rigidity. Meningitis)
    • Inflammatory conditions:
      • Guillain-Barré syndrome Guillain-Barré syndrome Guillain-Barré syndrome (GBS), once thought to be a single disease process, is a family of immune-mediated polyneuropathies that occur after infections (e.g., with Campylobacter jejuni). Guillain-Barré Syndrome
      • Multiple sclerosis Multiple Sclerosis Multiple sclerosis (MS) is a chronic inflammatory autoimmune disease that leads to demyelination of the nerves in the CNS. Young women are more predominantly affected by this most common demyelinating condition. Multiple Sclerosis
    • Idiopathic intracranial hypertension Idiopathic Intracranial Hypertension Idiopathic intracranial hypertension (IIH), also known as pseudotumor cerebri, is a clinical disorder that presents with symptoms due to increased intracranial pressure (ICP; ≥ 20 mm Hg) or CSF pressure (> 250 mm H2O), with no structural changes or other attributable causes. Idiopathic Intracranial Hypertension (pseudotumor cerebri)
    • Normal-pressure hydrocephalus
    • New-onset seizures Seizures A seizure is abnormal electrical activity of the neurons in the cerebral cortex that can manifest in numerous ways depending on the region of the brain affected. Seizures consist of a sudden imbalance that occurs between the excitatory and inhibitory signals in cortical neurons, creating a net excitation. The 2 major classes of seizures are focal and generalized. Seizures
    • Cerebritis due to systemic lupus erythematosus Systemic lupus erythematosus Systemic lupus erythematosus (SLE) is a chronic autoimmune, inflammatory condition that causes immune-complex deposition in organs, resulting in systemic manifestations. Women, particularly those of African American descent, are more commonly affected. Systemic Lupus Erythematosus ( SLE SLE Systemic lupus erythematosus (SLE) is a chronic autoimmune, inflammatory condition that causes immune-complex deposition in organs, resulting in systemic manifestations. Women, particularly those of African American descent, are more commonly affected. Systemic Lupus Erythematosus)
  • Treatment:
    • Spinal analgesia
    • Administration of chemotherapeutic drugs or antibiotics

Contraindications

Absolute:

  • Local skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Structure and Function of the Skin infection
  • Increased intracranial pressure
  • Supratentorial mass
  • Severe coagulopathy
  • Hemodynamic instability

Procedure

Preoperative preparation:

  • Explain the procedure to the individual and obtain informed consent.
  • The individual is placed in the left or right lateral decubitus position.
    • The individual is instructed to draw the knees to the belly and head toward the chest (“curl up into a ball”) with the back near the edge of the bed.
  • The puncture site is identified and marked:
    • An imaginary line is drawn between the iliac crests.
    • The imaginary line intersects the spinous process of L4.
    • The space between L2–L3, L4–L5, or L5–S1 is identified for puncture.
  • The site of puncture is washed with a skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Structure and Function of the Skin-sterilizing solution and covered with sterile drapes.
  • The operator must don adequate PPE.

Technique:

  1. Local anesthetic (1% lidocaine) is infiltrated, making a wheal around the proposed puncture site.
  2. A 20- or 22-gauge spinal needle is carefully inserted through the skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Structure and Function of the Skin, aligned with the midline.
    • The needle is guided with the nondominant thumb and forefinger.
    • The point of the needle needs to face upward.
  3. The needle is advanced until it reaches the spinal canal.
    • A “popping” sensation and a drop in resistance is felt when the needle pierces the dura. 
    • If bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Structure of Bones is met, the needle can be slightly withdrawn and advanced in a somewhat different trajectory.
  4. The stylet is removed to check for CSF.
    • Entrance to the spinal canal is confirmed by the flow Flow Blood flows through the heart, arteries, capillaries, and veins in a closed, continuous circuit. Flow is the movement of volume per unit of time. Flow is affected by the pressure gradient and the resistance fluid encounters between 2 points. Vascular resistance is the opposition to flow, which is caused primarily by blood friction against vessel walls. Vascular Resistance, Flow, and Mean Arterial Pressure of CSF through the needle. 
  5. A barometer may be used to measure the opening pressure of CSF.
  6. 2–3 mL of CSF is collected in 3 tubes for analysis.
    • If the fluid is bloody after the 1st few drops (known as traumatic tap), the needle is withdrawn and the tap is attempted on another site. 
    • Persistence of bloody tap in ≥ 2 sites raises suspicion for subarachnoid hemorrhage Subarachnoid Hemorrhage Subarachnoid hemorrhage (SAH) is a type of cerebrovascular accident (stroke) resulting from intracranial hemorrhage into the subarachnoid space between the arachnoid and the pia mater layers of the meninges surrounding the brain. Most SAHs originate from a saccular aneurysm in the circle of Willis but may also occur as a result of trauma, uncontrolled hypertension, vasculitis, anticoagulant use, or stimulant use. Subarachnoid Hemorrhage (SAH)
  7. Once all fluid has been collected, the needle is plugged with the stylet and withdrawn. 

Postprocedure care:

  • The individual will be under observation for at least 6 hours.
  • The headrest is elevated 30 degrees to prevent postpuncture headache.

Complications

  • Postpuncture headache
  • Traumatic spinal tap (hemorrhage)
  • Brain herniation
  • Spinal epidural or subdural hematoma
  • Disk herniation
  • Nerve root aspiration and injury
  • Meningitis

Arthrocentesis

Definition

  • The aspiration of synovial fluid directly from a joint for diagnostic and/or therapeutic purposes
  • Can potentially be performed in any synovial joint

Indications

  • Analysis of joint effusion and determination of etiology:
    • Septic arthritis Septic arthritis Septic arthritis is an infection of the joint due to direct inoculation, contiguous extension, or hematogenous spread of infectious organisms into the joint space. This process causes an acute, inflammatory, monoarticular arthritis. Septic Arthritis
    • Aseptic arthritis
    • Gout Gout Gout is a heterogeneous metabolic disease associated with elevated serum uric acid levels (> 6.8 mg/dL) and abnormal deposits of monosodium urate in tissues. The condition is often familial and is initially characterized by painful, recurring, and usually monoarticular acute arthritis, or "gout flare," followed later by chronic deforming arthritis. Gout
  • Removal of septic fluid from joint

Contraindications

  • Cellulitis Cellulitis Cellulitis is a common infection caused by bacteria that affects the dermis and subcutaneous tissue of the skin. It is frequently caused by Staphylococcus aureus and Streptococcus pyogenes. The skin infection presents as an erythematous and edematous area with warmth and tenderness. Cellulitis or skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Structure and Function of the Skin damage over the joint
  • Anticoagulation or severe coagulopathy
  • More than 3 injections in a weight-bearing joint in the past 12 months
  • Unstable joints
  • Difficult for primary care clinicians to access joints (e.g., hip joint Hip joint The hip joint is a ball-and-socket joint formed by the head of the femur and the acetabulum of the pelvis. The hip joint is the most stable joint in the body and is supported by a very strong capsule and several ligaments, allowing the joint to sustain forces that can be multiple times the total body weight. Hip Joint, sacroiliac joint)
    • Deeper joint aspirations should be performed by qualified operators.
    • Ultrasound or fluoroscopic guidance may be used.
  • Joint prosthesis

Procedure

Preoperative preparation:

  • Explain the procedure to the individual and obtain informed consent.
  • The individual is placed in the best position for the joint in question. For example:
    • Arthrocentesis of the knee requires the individual to be placed in the seated or dorsal decubitus position with the knee bent at a 45-degree angle. 
    • Arthrocentesis of the femoroacetabular joint requires the individual to be placed in the lateral decubitus (affected side up) or dorsal decubitus position.
  • The puncture site is selected by palpating the surrounding landmarks or by using ultrasound guidance. 
    • Tendons, major blood vessels, and nerves must be avoided.
    • Needle trajectory may be visualized in real time with the use of ultrasonography. 
  • The puncture site is washed with a skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Structure and Function of the Skin-sterilizing solution and covered with sterile drapes.
  • The operator must don adequate PPE.

Technique:

  1. Local anesthetic (1% lidocaine) is infiltrated, making a wheal around the proposed puncture site.
    • After the skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Structure and Function of the Skin has been infiltrated, the deeper tissues and joint capsules are infiltrated with anesthetic. 
    • Tubing may be left attached to the needle to facilitate syringe changes. 
  2. A needle, attached to a syringe of adequate size, is inserted into the joint space, following the anesthetized track (needle size needs to be proportional to the joint in question).
  3. Entry into the space is confirmed by the flow Flow Blood flows through the heart, arteries, capillaries, and veins in a closed, continuous circuit. Flow is the movement of volume per unit of time. Flow is affected by the pressure gradient and the resistance fluid encounters between 2 points. Vascular resistance is the opposition to flow, which is caused primarily by blood friction against vessel walls. Vascular Resistance, Flow, and Mean Arterial Pressure of synovial fluid into the syringe.
  4. The operator drains as much fluid (or blood) as possible, until no more can be withdrawn.
    • Fluid is placed in sterile tubes for analysis. 
    • To make sure the needle is not clogged by debris, the needle can be withdrawn slightly and advanced, or it can be rotated.
  5. The needle is withdrawn, and the puncture site is covered with sterile gauze and pressure is applied.
Introduction of the needle from the anteriolateral portal

Arthrocentesis of the right knee using the lateral infrapatellar approach

Image: “Introduction of the Needle from the Anteriolateral Portal” by Chavez-Chiang CE, Sibbitt WL, Band PA, Chavez-Chiang NR, Delea SL, Bankhurst AD. License: CC BY 2.0

Postoperative care Postoperative care After any procedure performed in the operating room, all patients must undergo close observation at least in the recovery room. After larger procedures and for patients who require hospitalization, observation must continue on the surgical ward. The primary intent of this practice is the early detection of postoperative complications. Postoperative Care:

  • Individual may return to regular activities afterward.
  • Further recommendations depend on the individual’s specific situation.

Complications

  • Infection of the surrounding tissue or joint
  • Hemorrhage and hemarthrosis (blood in the joint)

Clinical Relevance

The following are complications of cricothyroidotomy/tracheotomy:

  • Pneumothorax Pneumothorax A pneumothorax is a life-threatening condition in which air collects in the pleural space, causing partial or full collapse of the lung. A pneumothorax can be traumatic or spontaneous. Patients present with a sudden onset of sharp chest pain, dyspnea, and diminished breath sounds on exam. Pneumothorax: life-threatening condition in which air collects in the pleural space, causing partial or full collapse of the lung. Presentation is with the sudden onset of sharp chest pain Chest Pain Chest pain is one of the most common and challenging complaints that may present in an inpatient and outpatient setting. The differential diagnosis of chest pain is large and includes cardiac, gastrointestinal, pulmonary, musculoskeletal, and psychiatric etiologies. Chest Pain, dyspnea Dyspnea Dyspnea is the subjective sensation of breathing discomfort. Dyspnea is a normal manifestation of heavy physical or psychological exertion, but also may be caused by underlying conditions (both pulmonary and extrapulmonary). Dyspnea, and diminished breath sounds on exam. Symptom severity depends on the degree of collapse of the lung. Diagnosis is made with imaging, though tension pneumothorax is a clinical diagnosis. Management is based on the size and stability of the individual and can include needle decompression and chest tube placement (thoracostomy).
  • Pneumomediastinum: presence of air in the mediastinum Mediastinum The mediastinum is the thoracic area between the 2 pleural cavities. The mediastinum contains vital structures of the circulatory, respiratory, digestive, and nervous systems including the heart and esophagus, and major thoracic vessels. Mediastinum and Great Vessels. Clinical presentation is characterized by dyspnea Dyspnea Dyspnea is the subjective sensation of breathing discomfort. Dyspnea is a normal manifestation of heavy physical or psychological exertion, but also may be caused by underlying conditions (both pulmonary and extrapulmonary). Dyspnea, and subcutaneous emphysema is a common finding. Diagnosis is made with imaging, preferably a CT scan of the thorax. Management can be conservative in stable individuals or surgical, by means of decompression, in severe cases. 
  • Tracheoesophageal fistula Tracheoesophageal fistula Tracheoesophageal fistula is an abnormal connection between the trachea and esophagus. Esophageal Atresia and Tracheoesophageal Fistula: pathologic communication between the trachea Trachea The trachea is a tubular structure that forms part of the lower respiratory tract. The trachea is continuous superiorly with the larynx and inferiorly becomes the bronchial tree within the lungs. The trachea consists of a support frame of semicircular, or C-shaped, rings made out of hyaline cartilage and reinforced by collagenous connective tissue. Trachea and the esophagus Esophagus The esophagus is a muscular tube-shaped organ of around 25 centimeters in length that connects the pharynx to the stomach. The organ extends from approximately the 6th cervical vertebra to the 11th thoracic vertebra and can be divided grossly into 3 parts: the cervical part, the thoracic part, and the abdominal part. Esophagus. Individuals can present with gastric distention due to air leaking into the esophagus Esophagus The esophagus is a muscular tube-shaped organ of around 25 centimeters in length that connects the pharynx to the stomach. The organ extends from approximately the 6th cervical vertebra to the 11th thoracic vertebra and can be divided grossly into 3 parts: the cervical part, the thoracic part, and the abdominal part. Esophagus and frequent gastric reflux and aspiration pneumonia Pneumonia Pneumonia or pulmonary inflammation is an acute or chronic inflammation of lung tissue. Causes include infection with bacteria, viruses, or fungi. In more rare cases, pneumonia can also be caused through toxic triggers through inhalation of toxic substances, immunological processes, or in the course of radiotherapy. Pneumonia, as well as hemoptysis Hemoptysis Hemoptysis is defined as the expectoration of blood originating in the lower respiratory tract. Hemoptysis is a consequence of another disease process and can be classified as either life threatening or non-life threatening. Hemoptysis can result in significant morbidity and mortality due to both drowning (reduced gas exchange as the lungs fill with blood) and hemorrhagic shock. Hemoptysis. Diagnosis is made with contrast esophagography, and definitive management is surgical. 

The following are complications of paracentesis:

  • Hypotension: defined as low blood pressure, specifically < 90/60 mm Hg. Hypotension is most commonly a physiologic response. Hypotension may be mild, serious, or life-threatening, depending on the cause. Clinically significant complications may occur when blood pressure falls enough for crucial organs to become insufficiently perfused. Diagnostic studies and treatment depend on the clinical presentation and underlying conditions.

The following are complications of incision and drainage of superficial abscesses:

  • Surgical site infection ( SSI SSI Surgical site infection (SSI) is a type of surgical infection that occurs at or near a surgical incision within 30 days of the procedure or within 90 days if prosthetic material is implanted. Surgical site infections are classified according to the depth of involvement as superficial, deep, or organ/space. Surgical Site Infections): type of surgical infection Surgical infection An infection is the proliferation of microorganisms within tissues, body cavities, or spaces, which induces an immune response and overwhelms the body's natural defenses. In surgical patients, these infections are frequently caused by the translocation of commensal organisms into deeper tissues, combined with the impairment of host defenses due to surgical injury or stress. Surgical Infections that occurs at or near a surgical incision within 30 days after the procedure or within 90 days if prosthetic material is implanted. An SSI SSI Surgical site infection (SSI) is a type of surgical infection that occurs at or near a surgical incision within 30 days of the procedure or within 90 days if prosthetic material is implanted. Surgical site infections are classified according to the depth of involvement as superficial, deep, or organ/space. Surgical Site Infections is classified according to the depth of involvement as superficial, deep, or organ/space. Diagnosis relies on clinical findings and may require diagnostic imaging. Management involves antibiotics as well as surgical drainage/debridement as necessary.
  • Cellulitis Cellulitis Cellulitis is a common infection caused by bacteria that affects the dermis and subcutaneous tissue of the skin. It is frequently caused by Staphylococcus aureus and Streptococcus pyogenes. The skin infection presents as an erythematous and edematous area with warmth and tenderness. Cellulitis: common infection caused by bacteria Bacteria Bacteria are prokaryotic single-celled microorganisms that are metabolically active and divide by binary fission. Some of these organisms play a significant role in the pathogenesis of diseases. Bacteriology: Overview, affecting the dermis and subcutaneous tissue of the skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Structure and Function of the Skin. Cellulitis Cellulitis Cellulitis is a common infection caused by bacteria that affects the dermis and subcutaneous tissue of the skin. It is frequently caused by Staphylococcus aureus and Streptococcus pyogenes. The skin infection presents as an erythematous and edematous area with warmth and tenderness. Cellulitis is frequently caused by Staphylococcus Staphylococcus Staphylococcus is a medically important genera of Gram-positive, aerobic cocci. These bacteria form clusters resembling grapes on culture plates. Staphylococci are ubiquitous for humans, and many strains compose the normal skin flora. Staphylococcus aureus and Streptococcus Streptococcus Streptococcus is one of the two medically important genera of gram-positive cocci, the other being Staphylococcus. Streptococci are identified as different species on blood agar on the basis of their hemolytic pattern and sensitivity to optochin and bacitracin. There are many pathogenic species of streptococci, including S. pyogenes, S. agalactiae, S. pneumoniae, and the viridans streptococci. Streptococcus pyogenes. Clinical presentation includes an erythematous and edematous area with warmth and tenderness. The borders are not clearly delineated. The lower extremities are the most frequent site of infection. Diagnosis is usually clinical, and management involves oral and/or parenteral antibiotics. Coverage for MRSA is added, depending on risk factors.

The following are complications of lumbar puncture:

  • Brain herniation: abnormal displacement of CNS structures within the cranial vault. Among the types of brain herniation are subfalcine, central transtentorial, uncal, and cerebellotonsillar. Clinical presentation varies according to the type of herniation, but it can be as severe as respiratory depression. Diagnosis is clinical, and management involves measures to lower ICP ICP Normal intracranial pressure (ICP) is defined as < 15 mm Hg, whereas pathologically increased ICP is any pressure ≥ 20 mm Hg. Increased ICP may result from several etiologies, including trauma, intracranial hemorrhage, mass lesions, cerebral edema, increased CSF production, and decreased CSF absorption. Increased Intracranial Pressure (ICP)
  • Disk herniation: expulsion of the nucleus pulposus through a perforation in the annulus fibrosus of the intervertebral disk. Disk herniation is an important pain Pain Pain has accompanied humans since they first existed, first lamented as the curse of existence and later understood as an adaptive mechanism that ensures survival. Pain is the most common symptomatic complaint and the main reason why people seek medical care. Physiology of Pain syndrome with the potential for neurologic impairment and is most commonly caused by degenerative disk disease. Clinical presentation depends on the downstream neurologic sequelae of the presence or absence of spinal cord Spinal cord The spinal cord is the major conduction pathway connecting the brain to the body; it is part of the CNS. In cross section, the spinal cord is divided into an H-shaped area of gray matter (consisting of synapsing neuronal cell bodies) and a surrounding area of white matter (consisting of ascending and descending tracts of myelinated axons). Spinal Cord or nerve root compression. Diagnosis is initially clinical and can be confirmed with diagnostic imaging (i.e., MRI). Management‌ ‌can be conservative or surgical, depending on the situation.
  • Meningitis: inflammation Inflammation Inflammation is a complex set of responses to infection and injury involving leukocytes as the principal cellular mediators in the body's defense against pathogenic organisms. Inflammation is also seen as a response to tissue injury in the process of wound healing. The 5 cardinal signs of inflammation are pain, heat, redness, swelling, and loss of function. Inflammation of the meninges Meninges The brain and the spinal cord are enveloped by 3 overlapping layers of connective tissue called the meninges. The layers are, from the most external layer to the most internal layer, the dura mater, arachnoid mater, and pia mater. Between these layers are 3 potential spaces called the epidural, subdural, and subarachnoid spaces. Meninges, the protective membranes of the brain and spinal cord Spinal cord The spinal cord is the major conduction pathway connecting the brain to the body; it is part of the CNS. In cross section, the spinal cord is divided into an H-shaped area of gray matter (consisting of synapsing neuronal cell bodies) and a surrounding area of white matter (consisting of ascending and descending tracts of myelinated axons). Spinal Cord. The etiologies of meningitis Meningitis Meningitis is inflammation of the meninges, the protective membranes of the brain, and spinal cord. The causes of meningitis are varied, with the most common being bacterial or viral infection. The classic presentation of meningitis is a triad of fever, altered mental status, and nuchal rigidity. Meningitis are varied, with the most common being bacterial or viral infection. The classic presentation of meningitis Meningitis Meningitis is inflammation of the meninges, the protective membranes of the brain, and spinal cord. The causes of meningitis are varied, with the most common being bacterial or viral infection. The classic presentation of meningitis is a triad of fever, altered mental status, and nuchal rigidity. Meningitis is a triad of fever Fever Fever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever, altered mental status, and nuchal rigidity. Diagnosis of meningitis Meningitis Meningitis is inflammation of the meninges, the protective membranes of the brain, and spinal cord. The causes of meningitis are varied, with the most common being bacterial or viral infection. The classic presentation of meningitis is a triad of fever, altered mental status, and nuchal rigidity. Meningitis is made on clinical grounds with a thorough neurologic examination. CSF analysis is an important diagnostic tool, as it is difficult to identify the exact etiology clinically. Management of meningitis Meningitis Meningitis is inflammation of the meninges, the protective membranes of the brain, and spinal cord. The causes of meningitis are varied, with the most common being bacterial or viral infection. The classic presentation of meningitis is a triad of fever, altered mental status, and nuchal rigidity. Meningitis includes immediate broad-spectrum antibiotics and supportive therapy to prevent complications.

References

  1. Wilson, J. (2018). Ear, nose and throat surgery. In: Garden, O.J., Parks, R.W. (Eds.), Principles and Practice of Surgery, 7th ed., pp. 502–527. Elsevier.
  2. Quick, C. R. G., Biers, S. M., & Arulampalam, T. H. A. (2020). Thoracic surgery. In: Quick, C. R. G., Biers, S. M., & Arulampalam, T. H. A. (Eds.), Essential Surgery: Problems, Diagnosis and Management, 6th ed., pp. 421–431. Elsevier.
  3. Roden, D. (2020). Cricothyroid catheter insertion, cricothyroidotomy, and tracheostomy. In: Fowler, G. C. (Ed.), Pfenninger and Fowler’s Procedures for Primary Care, pp. 1485–1492. Elsevier.
  4. Skye, E. (2020). Abdominal paracentesis. In: Fowler, G. C. (Ed.), Pfenninger and Fowler’s Procedures for Primary Care, pp. 1461–1465. Elsevier. 
  5. Pastorino, A., Tavarez, M. M. (2021). Incision and drainage. StatPearls. Retrieved December 1, 2021, from http://www.ncbi.nlm.nih.gov/books/NBK556072/ 
  6. German, J. A., & O’Brien, J. (2020). Lumbar puncture. In: Fowler, G. C. (Ed.), Pfenninger and Fowler’s Procedures for Primary Care, pp. 1471–1476. Elsevier.
  7. Tantillo, T. J., Katsigiorgis, G. (2021). Arthrocentesis. StatPearls. Retrieved December 1, 2021, from http://www.ncbi.nlm.nih.gov/books/NBK557805/ 
  8. Barkdull, T. J., O’Connor, F. G., & McShane, J. M. (2020). Joint and soft tissue aspiration and injection (Arthrocentesis). In: Fowler, G. C., Pfenninger and Fowler’s Procedures for Primary Care, pp. 1221–1239. Elsevier.

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