Gettin My Learn On Flashcards
What are important acute side effects of prostaglandin E1? And one chronic side effect?
Apnea, hypotension and fever. Chronic = clubbing.
What is the formula for estimating cuffed and uncuffed ETT size (diameter) in kids? Premies? Term neonates? What is the formula for estimating ETT depth?
ETT size (diameter in mm): age/4 + 4 for uncuffed tubes *Drop the size by 0.5 for cuffed tubes* Premies: 2.5 to 3 (uncuffed) Term neonates: 3 to 3.5 (uncuffed) ETT depth in cm: age/2 + 12 [practical note: ETT size x3]
Epidural fentanyl:
a) What is the most common side effect?
b) Can it cross the placenta?
c) Does it contribute to neonatal respiratory depression?
d) One adverse thing it can cause in the fetus:
e) Does intrathecal fentanyl contribute to maternal respiratory depression?
Epidural fentanyl:
a) What is the most common side effect? Pruritis
b) Can it cross the placenta? Yes
c) Does it contribute to neonatal respiratory depression? Not under normal circumstances
d) One adverse thing it can cause in the fetus: Transient decrease in fetal heart rate variability (b/c crosses placenta)
e) Does intrathecal fentanyl contribute to maternal respiratory depression? No, because unlike morphine it is highly lipophillic and does not have significant rostral spread in the intrathecal space.
Name 3 factors that increase materal risk for abnormal placentation (accreta, increta, percreta).
Which one confers the HIGHEST risk?
Advanced maternal age, placenta previa and prior c-section.
Greatest risk = Placenta Previa.
- By a long shot. Odds ration is 51.4, whereas it is 2.2 for 1 prior C/S and 8.6 for 2 prior C/S’s. Combine them both and the risk is markedly higher.
- What are some characteristic ECG changes with magnesium toxicity?
- Can magensium be dialyzed off?
- ECG changes are inconsistent actually, but commonly include prolongation of the P-R interval and a widening of the QRS complex
- Yes magnesium can be dialyzed
Can you explain the cardiovascular changes of pregnancy?
Cardiovascular changes in pregnancy revolve around the themes of increasing cardiac output and extending blood flow to the placenta. HR and SV increase, while SVR decreases to reduce afterload and maintain a relatively normal blood pressure.
As a result of the increased blood volumes occupying the heart, a mild but normal cardiomegaly can be seen and an S3 can be heard. Dilation of the heart can also cause new regurgitant murmurs, particularly TR, with a resulting systolic murmur. The dilation can temporarily alter conduciton in the heart, leading to right-axis deviation and RBBB.
Note: An S4 is almost always pathologic, even in pregnant patients.
What are 5 physiological changes that occur in pregnancy to improve oxygen delivery to the fetus (2 resp, 1 CV, 2 heme)?
- MV increases (due to increases in RR and Vt)
- PaO2 increases (also due to increases in RR and Vt)
- CO increases
- RBC # increases by 30%
- Blood volume increases by 45% at term (decreased hematocrit, aka “physiologic anemia of pregnancy”)
Pregnant patients have a MAC that is depressed by what percentage compared to non-pregnant patients?
Depressed by 25-40%
IV magnesium given for seizure prophylaxis in pre-eclamptic patients:
- What are normal serum levels of Mg++?
- What therapeutic range are we aiming for in pre-eclampsia?
- ECG changes can develop at serum levels how high?
- Pts with elevated serum Mg++ can be more sensitive to which NMBDs?
- What is the mechanism? (hint: same reason DTRs are depressed with toxicity)
IV magnesium given for seizure prophylaxis in pre-eclamptic patients:
- What are normal serum levels of Mg++?
- 1.2 - 2.0 mEq/L
- What therapeutic range are we aiming for?
- 4 - 8 mEq/L
- ECG changes can develop at serum levels how high?
- >5 mEq/L
- Pts with elevated serum Mg++ can be more sensitive to which NMBDs?
- Both depolarizing and non-depolarizing NMBDs
- What is the mechanism? (hint: same reason DTRs are depressed with toxicity)
- Mg++ depresses activity at the neuromuscular junction
Hepatic changes in pregnancy:
- Change in hepatic blood flow?
- Change in hepatic synthetic function?
- How does the liver shift?
- Effect on ALP? ALT? AST? Bili? LDH?
- Effect on albumin?
- Change in plasma cholinesterase activity?
- How clinically significant is this?
- Effect on cholecystokinin?
Hepatic changes in pregnancy:
- Change in hepatic blood flow?
- Unchanged
- Change in hepatic synthetic function?
- Unchanged
- How does the liver’s location shift?
- Upwards, posterior and to the right
- Effect on ALP? ALT? AST? Bili? LDH?
- ALP is secreted by the placenta; serum ALP levels increase 2 to 4-fold. ALT, AST, bili and LDH increase only slightly to the upper range of normal.
- Effect on albumin?
- Mild decrease due to plasma expansion
- Change in plasma cholinesterase activity?
- Reduced by 25-30% at term.
- How clinically significant is this?
- This is rarely clinically significant. Breakdown of ester local anesthetics and sux is minimally impacted.
- Effect on cholecystokinin?
- Cholecystokinin causes the release of bile from the gallbladder and digestive enzymes from the pancreas. High progesterone levels in pregnancy inhibit its release, causing reduced gallbladder emptying and increasing the risk of cholesterol gallstones and cholecystitis.
- What is the normal range for fetal HR?
110-160 bpm
What constitutes a “normal” FHR tracing?
The FHR stays within normal range and exhibits variability
What are some reasons for minimal or absent variability in the FHR (where the tracing shows little to no change in beat-to-beat HR)?
- Normal fetal sleep cycle
- CNS depression following opioid administration
- More serious fetal conditions
Explain each type of decels on the FHR tracing:
- Early decels
- Late decels
- Variable decels
Early decels:
- Occur as a result of vagal stimulaiton from compression of the fetal head
- Begin at the same time as the uterine contractions and also end at the same time
- Rarely does the HR drop lower than 20 bpm below fetal baseline
Late decels:
- There is a delay between start and end of the uterine contractions and drop in fetal HR (delay between peaks of contractions and nadirs of FHR)
- Signify uteroplacental insufficiency
Variable decels:
- Less uniform in shape compared with early and late decels
- Timing is less coincident with the uterine contractions
- Cause = umbilical cord compression, usually
- What is the critical level of fibrinogen?
- During hemorrhage, how many blood volumes need to be lost before reaching a critical level?
- How many blood volumes need to be lost for other coagulation factors (and plts and thrombin) to reach critical levels?
- What is the critical level of fibrinogen? 100 mg/dL
- During hemorrhage, how many blood volumes need to be lost before reaching a critical level? 1.5 blood volumes
- How many blood volumes need to be lost for other coagulation factors (and plts and thrombin) to reach critical levels? 2 to 2.5 blood volumes
