Physiologic Changes in Pregnancy: Respiratory and Renal System (Nursing)

00:00 Okay, look what happens in respiratory. You have increased arterial oxygen tension.

00:05 That's cool. It's highest in the first trimester into a lesser extent in the third trimester but as that baby is developing, everybody needs more oxygen so you have increased arterial oxygen.

00:17 That's kinda really cool, I think.

00:19 But there's a 10 to 20% increase in the baseline O2 consumption.

00:24 By why is that? It's hard work growing a human.

00:30 So that's why you have increased arterial oxygen tension because you have increased need for your baseline consumption goes up.

00:38 You also have increased vascularity and edema of the upper respiratory mucosa so that's why you need more from your respiratory system.

00:46 So look at those 3 examples: extra arterial oxygen tension, remember it's highest in the first trimester then to a lesser extent in the third, 10-20% increase in baseline O2 consumption so I've got more arterial oxygen cuz I'm using it and I need it, and I also have increased vascularity and edema in my upper respiratory mucosa.

01:09 So what difference does that make? What clinical considerations do I need to make? Keep in mind, inhaled medications may be more readily absorbed by pregnant patients.

01:18 So listen to your patients.

01:20 Ask them about their inhaled medications, have they noticed any difference in their body, and help them problem solve from there.

01:27 Now I'm talking about aerobic exercise in pregnancy.

01:30 Every time I go to the gym and I see women who are, you know, very, very pregnant and they're still working out, it's inspiring cuz I think it's hard to go and I'm not pregnant but these women are committed.

01:43 Here's the good news about aerobic exercise in pregnancy.

01:48 Now, you have an increased resting oxygen requirement, right? An increased work of breathing, we have this enlarged uterus on the diaphragm, I just got more room for everything to move around, scraped my diaphragm to be able to contract right, to expand, and if I'm full of baby, there's just not a lot of room especially if you're short-bodied.

02:09 So you have an increased resting oxygen requirement because you're pregnant and now I've got these growing features inside my body so it makes less room for my diaphragm and my lungs and on my organs.

02:23 Well, look at the fit realms.

02:26 There's less O2 available for most people for aerobic exercise if they're pregnant but we found out is some women who were fit before they were pregnant, they don't go through these changes. So they literally breathe easier.

02:40 So if you weren't fit before, you got increased resting oxygen requirement, you got less room available, there's less oxygen available for aerobic exercise so it's going to be harder.

02:53 But there are some women who were on it before pregnancy, they're really into fitness, they were consistent, they don't experience the same changes that most pregnant women do.

03:03 So they don't have any change in aerobic power or their acid-base balance in exercise during pregnancy.

03:08 That is impressive.

03:11 So we've talked about cardiovascular, we've talked about respiratory, and we even talked about incredible fit pregnant women who don't go through the same respiratory issues that a lot of us do.

03:23 Now we're gonna look at the changes in the renal system.

03:26 Now we know that the urinary collecting system is kinda dilated.

03:30 You end up having some urinary stasis.

03:32 Pregnant women have an increased risk for UTI that's why they're pre-disposed.

03:37 Because the urinary collection system is dilated, and they have some urine kinda hanging around.

03:43 Not good for it to hang around because it makes them more prone to UTIs.

03:48 They also have increased renal blood flow and GFR.

03:51 So everything is stepped up in their body.

03:54 Their heart, their lungs, and their kidneys.

03:56 One drawback is that risk for UTIs.

04:00 Now, it can reduce the drug half-lives so we're talking about so okay, we know the kidneys are going through this, what difference does that make to a pregnant woman? Well, it can reduce the drug half-lives and increase renal clearance and elimination rates.

04:13 So the health care provider may have to adjust the dosage of certain drugs.

04:18 Sodium and water retention leads to volume expansion so we've got to watch that carefully in pregnant patients.

04:26 And reduction in serum concentration of hydrophilic drugs will also occur.

04:31 So there's a lot of special information that health care provider needs to keep in mind as far as the hydrophilic status of a drug and the renal function of a pregnant patient.