Renal Case: 81-year-old Man with Depression

00:01 Okay, let's go through a clinical case to test our knowledge.

00:06 We have an 81-year-old gentleman weighing 60 kilograms with a history of dementia who was admitted to the hospital with worsening delirium.

00:13 So, that means he's got altered mentation.

00:15 And he was previously residing in a skilled nursing facility.

00:19 He was initially admitted the skilled nursing facility for physical rehabilitation following a hospitalization for pneumonia.

00:25 His exam is significant for a blood pressure of 90/66.

00:29 His pulse rate is 98 beats per minute, and he's got tenting of the skin, dry mucous membranes, and an undetectable jugular venous pressure.

00:38 His serum sodium is 155 mEq/L and his urine osmolality is 660 mOsmol/kg.

00:45 He is noted to have only 620 mL of urine output over the past 24 hours.

00:52 So which statement is true regarding this gentleman's hypernatremia? Letter A.

00:58 There is resistance to ADH at the collecting tubule.

01:00 Letter B.

01:01 There's insufficient release of ADH from the posterior pituitary.

01:06 Letter C.

01:07 There is insufficient access to free water and reduced thirst sensation.

01:11 Or letter D, there is hypertonic sodium gain from the diet he is received at the skilled nursing facility.

01:21 Let's go through our clinical case and see if we can arrive at the correct answer.

01:26 Step one, we want to determine the volume status.

01:29 The patient has hypovolemic hypernatremia.

01:31 He's hypotensive and has flat neck veins on physical exam.

01:36 Step two, we want to determine if the ADH is either present or absence.

01:40 In this case, his urine Osm is greater than a serum Osm.

01:43 Therefore, ADH is present and working.

01:48 So let's go through our statements again.

01:51 There is resistance to ADH at the collecting tubule.

01:55 Incorrect.

01:56 The Urine Osm is 600 mOsmol/kg.

01:59 That means, ADH is present.

02:03 Letter B.

02:04 There is insufficient release of ADH from the posterior pituitary.

02:08 Same as in letter A, Urine Osm is 600 mOsmol/kg.

02:13 It's greater than the serum osmolality.

02:16 ADH is present in this case.

02:19 Let's skip letter C for right now and go to letter D.

02:22 There is hypertonic sodium gain from the diet that he has received at the skilled nursing facility.

02:28 Incorrect.

02:29 This is rarely a cause of hypernatremia and if it is, it's typically associated with hypertonic saline solutions, irrigant solutions.

02:37 Were surreptitious poisoning or 'salting' customs, not the case in this gentleman.

02:43 Let's go back to letter C.

02:45 There is insufficient access to free water and reduced to thirst sensation.

02:50 This is correct.

02:51 ADH is appropriate based on his Urine Osm, but the patient likely does not have free access to water in the skilled nursing facility.

02:59 And given his advanced to age and dementia, he may have hypodipsia or reduced thirst.

03:07 Alright, excellent job at assimilating the information and arriving at the correct diagnosis.

03:13 Patients with hypo and hypernatremia are probably some of the most challenging patients that you're going to care for.

03:19 But with a good conceptual understanding and practice, you will be able to solve any problem and water balance that comes your way.

03:27 And with that, we conclude our lecture.