Chapter 22: Cardiovascular and Respiratory Distress Disorders

Question 1

How often do HTN isues happen in pregnancy?

Answer 1

12-22% of the time in pregnancy

Question 2

Accountable for 20% of maternal deaths in the U.S

Answer 2

HTN during pregnancy

Question 3

Most common cause of HTN in pregnancy?

Answer 3

Causes remain unknown

Question 4

What defines chronic HTN?

Answer 4

Chronic HTN: Prior to 20 weeks pregnancy or persisting after 12 weeks post-partum.

Question 5

How do we classify chronic HTN?

Answer 5

Classification: Mild = Systolic 140-159 or Diastolic 90 - 109. Severe = Systolic 160+ or Dia 110+

Question 6

30% of people with HTN in pregnancy develop this:

Answer 6

Pre-ecclampsia

Question 7

What is gestational HTN? How often does it occur?

Answer 7

Gestational HTN: HTN that develops for the first time after 20 weeks gestation in the absence of proteinuria. Happens in 5 - 10% of pregnancies, with a 30% incidence in multigestational preg.

Question 8

Does Gestationam HTN lead to pre-ecclampsia?

Answer 8

50% of these patients go on to develop pre-ecclampsia with 10% of ecclamptic seizures happening before overt proteinuria

Question 9

How do we define pre-ecclampsia? Is edema an indicative physical exam finding?

Answer 9

Pre-ecclampsia: HTN with proteinuria after 20 weeks gestation. Edema is common, but its common anyway so this isn’t reliable.

Question 10

Risk factors for pre-ecclampsia?

Answer 10

Risk factors: Nulliparity, Multifetal, Age 35+, Previous preecclampsia, chronic HTN, pregestational DM, Vascular disorders, Kidney issues, Antiphospholipid syndrome, obesity, being African American

Question 11

Specific criteria for pre-ecclampsia

Answer 11

Criteria: 140+/90+ after 20 weeks in a woman who previously did not have HTN. Proteinuria with urinary excretion of 0.3g or higher in a 24 hour urine sample.

Question 12

When do we classify pre-ecclampsia as “severe”?

Answer 12

Severe: Any of the following: 160+/110+ on 2 occasions at least 6 hours apart while patient is on bed rest. Marked proteinuria defined as urine dipstick with 3+ protein on two samples taken 4 hours apart or urine protein at 5g.

Oliguria less than 500mL in 24 hours. Cerebral or visual disturbances. Pulmonary edema or cyanosis. Epigastric/RUQ pain (probably due to subscapular hepatic hemorrhage or stretching of Glisson capsule with hepatocellular edema), evidence of hepatic dysfunction, thrombocytopenia, IUGR.

Question 13

Why do we care about classifying severe vs regular pre-ecclampsia?

Answer 13

Why we care: Severe = deliver no matter gestational age or maturity. You would only wait in certain circumstances for steroids to kick in, but this is a rare step

Question 14

What is ecclampsia?

Answer 14

Ecclampsia: Pre-ecclampsia with seizures, happens only 0.5 - 4% of pre-ecclamptic patients. Occur within 24 hours of delivery, but 10% of cases have it 2-10 days post-partum

Question 15

What is HELLP? What are the criteria?

Answer 15

HELLP: Hemolysis elevated liver enzymes and low platelets. Indication for delivery to avoid jeopardizing health of the woman. Happens in 4 - 12% of patiens with pre or regular ecclampsia.

Criteria: Microangiopathic hemolysis, thrombocytopenia, hepatocellular dysfunction

Question 16

What is the leading finding of HTN in pregnancy that we see in mom?

Answer 16

Pathophys of HTN in pregnancy - Maternal vasospasm is the leading finding

Question 17

5 potential causes of vasospasm leading to HTN in pregnancy

Answer 17

1. Vascular changes
2. Hemostatic changes
3. Changes to prostaglandins
4. Changes to prostanoids
5. Changes in endothelial derived factors

Question 18

Why vascular changes in pregnancy could lead to vasospasm?

Answer 18

Vascular changes: Endothelial damage in vessels and inadequate maternal vascular remodeling (normally we see trophoblast-mediated vascular changes in the uterine vessels with decreased musculature in the spiral arterioles that leads to development of low resistance, low pressure, high flow system)

Question 19

What hemostatic changes in pregnancy could lead to HTN?

Answer 19

Hemostatic changes - Particularly in pre-ecc. Increased platelet activation with increased consumption in microvasculature. Endothelial fibronectin levels are increased and anti-thrombin III and a2-antiplasmin levels decrease which reflect endothelial damage. Low AT3 are permissive for microthrombi development. Endothelial damage leads to further vasospasm.

Question 20

What prostanoid changes in pregnancy can lead to vasospasm and thus HTN?

Answer 20

Changes to prostanoids - Prostacyclin and Thromboxane increase with pregnancy, favoring Prostacyclin. Pre-ecclamptics get a favor for thromboxane. Prostacyclin favors vasodilation and decreased platelet aggregation with the opposite for thromboxane. Thromboxane thus leads to vessel constriction.

Question 21

What changes in endothelial derived factors during pregnancy can lead to vasospasm and HTN?

Answer 21

Changes in endothelium derived factors - Nitric Oxide, a potent vasodilator, is decreased in patients with pre-ecclampsia and may explain the evolution of vasoconstriction in these patients

Question 22

What free radical/antioxidant changes during pregnancy can lead to vasospasm and thus HTN?

Answer 22

Lipid peroxide, free radicals, and antioxidant release: Lipid peroxids and free radicals have been implicated in vascular injury and are increased in pregnancies complicated by pre-ecclampsia. Lower antioxidant levels noted.

Question 23

Discuss in general the hematologic effects seen in HTN pregnancy and what bad things can happen

Answer 23

Plasma volume contraction or hemoconcentration may develop with risk of rapid-onset hypovolemic shock when hemorrhage occurs.

We see this contraction of plasma with an elevated hematocrit.

Thrombocytopenia or DIC may also develop from the microangiopathic hemolytic anemia. Involvement of the liver may lead to hepatocellular dysfunction. Third spacing could occur due to increased blood pressure and decreased plasma oncotic pressure.

Question 24

Why do we see renal effects in some pregnancies with HTN?

Answer 24

Renal effects: Decreased GFR (increasing serum creatinine) and elevated protein cause decreased uric acid filtration that can be picked up on maternal serum as elevated uric acid on the blood.

Question 25

Why do we see pulmonary edema in some patients that are pregnant with HTN?

Answer 25

Pulmonary edema: Decreased colloid oncotic pressure, pulmonary capillary leak, left heart failure, iatrogenic fluid overload.

Question 26

Fetal effects with a HTN mom during pregnancy?

Answer 26

IUGR due to increased vasospasms interrupting flow to fetus, decreasing fluids (oligohydramnios) and increased perinatal mortality. We also see elevated occurrences of placental abruption or decreased placental development and size.

Question 27

What red flags in a history could be pointing to vasospasm?

Answer 27

History: Big red flag is visual disturbances, specifically scotomata or unusually severe or persistent headaches are indicative of vasospasm.

Question 28

Physical exam findings of HTN in pregnancy?

Answer 28

PE: Patient position influences BP. Laying down in lateral position gives you lowest. Highest when the patient is standing, intermediate when sitting. Also edema that does not relieve with supine position and that is present on the face or UEs is not normal.

Question 29

3 Lab types we need to be thnking about with a HTN mother during pregnancy

Answer 29

1. Hematologic change: Elevated hematocrit signifies worsening vasoconstriction and decreased intravascular volume. Decreasing hematocrit could mean hemolysis.

Thrombocytopenia indicates worsening disease, as does coagulopathy (PT and PTT).

(Get CBC and Coags).

2. Liver: Hepatocellular dysfunction is linked to worsening disease. Get a liver panel.
3. Kidneys: Decreased renal function is also a bad sign. Get Serum Cr (elevated), Uric acid (elevated), 24 hour urine, and total urinary protein (elevated).

Question 30

How do we manage chronic HTN during pregnancy

Answer 30

Chronic HTN: Use antihypertensives when BP is 150-160/100-110 to reduce liklihood of heart attack or stroke. Methyldopa is good, combined a/B blocker like labetalol is cool too and Ca channel blockers like nifedipine is increasing in use. No ACE inhibitors or ARBs, they cause fetal malformations. Diuretics are actually ok, I hada question on using furosemide in a HTN patient.

Question 31

How should we manage pre-ecclamptics during pregnancy?

Answer 31

Pre-ecclampsia: Deliver the baby, seriously. If it’s REAL MILD, you can do expectant. In this scenario, check for suspected fetal growth restriction or oligohydramnios with twice weekly NSTs, BPPs or both.

In severe if we can’t deliver, Mg Sulfate and anti-hypertensives with lots of monitoring is indicated.

Question 32

What happens with too much magnesium and what do we do about it?

Answer 32

Be careful on the magnesium level, as elevated serum concentrations beyond the 4-6 mg/dL can cause EKG changes, then loss of petallar reflex and flushing, slurred speech and respiratory failure and possible cardiac arrest at very high levels (30 mg/dL). Reverse elevated Mg Sulfate levels with slow IV push of 10% calcium gluconate and oxygen supplementation if needed.

Question 33

When would we use anti-hypertensives in pregnancy?

Answer 33

Antihypertensive when >160/

Question 34

What do we do if mom starts having ecclamptic seizures?

Answer 34

Ecclamptic seizures: Dangerous to mom and baby. Manage her airway to prevent aspiration or biting tongue and don’t try and deliver. Place a foley to watch urine output. Stabilize mom before delivery.

Question 35

How do we manage HELLP patients?

Answer 35

HELLP: Transfuse patients with really low platelets (

Question 36

Why do we worry about heart patients during pregnancy?

Answer 36

Cardiac patients: 50% of cardiac pregnant patients have a rheumatic heart disease or infectious valve from drug use. Need to be careful as we are increasing cardiac output by about 40%, so these, along with the other 50% with all kinds of heart issues, will get profoundly more dangerous.

Question 37

The following diagnoses basically mean you shouldn’t get pregnant cause you’ll probably die

Answer 37

PPH, tetrology of fallot that has not been corrected, Eisenerger syndrome, marfan syndrome with aortic root dilation, dilated cardiomyopathy

Question 38

What do we need to consider about the labor process with cardiac patients?

Answer 38

Try and do vaginal birth as C-S in stressed heart patients is not good, and you should do it in the lateral position to give adequate cardiac function.

Consider the use of a vacuum or forceps also to reduce time in the second stage, which leads to a 40-50% increase in cardiac output.

Also be careful post-partum because 500mL comes back into circulation as the uterus contracts down, which is the most common time for cardiac patients to die.

Question 39

What arrhythmias do we see with pregnancy and why

Answer 39

Paroxysmal atrial tachycardia is the most common encountered maternal arrhythmia and is usually associated with overly strenuous exercise. If atrial flutter or fibrillation is seen, suspect mitral valve stenosis.

Question 40

How do asthmatics do with all of this pregnancy shit?

Answer 40

Asthma. 1/3 of patients have worsened breathing, 1/3 have improved breathing, 1/3 have no change.

Question 41

As far as respiration numbers go, ______ ____ is associated with increased risk of low birthweight and prematurity.

Answer 41

Decreased FEV1 is associated with increased risk of low birthweight and prematurity.

Question 42

How do we deal with influenza for mom during pregnancy?

Answer 42

Influenza: Causes pneumonia in pregnant women more than non pregnant women. Diagnose with a rapid flu assay. Supportive care with antiviral therapy.The virus does not affect the baby directly, just mom, but mom reaction can lead to hypoxia and exposure to hyperthermia due to mom fever. Vaccinate at any time during pregnancy as it stops 70-90% of cases. NO CONTRAINDICATIONS TO INACTIVATED FLU VACCINE FOR BABY.