Pregnant and Sick: Haney Mallemat (AllNYCEM6)
- Mar 14th, 2014
- Adaira Landry
Pregnant and Sick: Management of the Critically Ill and Expectant
Haney Mallemat (@CriticalCareNow)
*Graduate from SUNY Downstate/Kings County; Critical Care Fellowship Dartmouth Hitchcock Medical Center, Currently Assistant Professor at University of Maryland.
Dr. Mallemat opens the lecture with a case of a 36 year old pregnant female with HR of 112, BP 100/65 and O2Sat of 92% and asks, “What vital sign should we be most concerned about?” The oxygen saturation! Hypoxia will hurt the mother and developing fetus.
He then rapidly enters into a high-yield lecture on the general approach to the sick pregnant patient.
We know that trauma is the #1 killer in pregnant women and that critical medical illness is rare. Most of our pregnant patients are young with great physiologic reserve and good outpatient follow-up. However, with growing trends of older pregnant patients, mortality can be higher due to concomitant disease like diabetes and hypertension. We must remember that fetal mortality is 100% dependent on maternal mortality.
EVERY single organ system is affected in pregnant body. If you want a general review of all the normal physiologic changes in pregnancy check out http://www.ncbi.nlm.nih.gov/pubmed/15388191. But during this lecture we focused mostly on the cardiac (perfusion) and pulmonary (diffusion) changes that normally occur.
Cardiac: 50% increase in CO by 3rd trimester and patients are more tachycardic, with higher stroke volume and increase in red cell volume and mass. About 25% of that CO goes to placenta alone. Most of the data on objective hemodynamic goals are from the OR, ICU or animal studies. Best evidence is to keep MAP >65 and SBP>100.
Pulmonary: Mother has increased respiratory rate, increased minute ventilation, and tidal volume to keep PaO2 normal. FRV gives us all reserve but patients lose this with big fetus. These patients can desaturate QUICKLY! Objective respiratory goals are PaO2>70 or peripheral oxygen saturation > 95%. PaO2 < 60mmHg is dangerous for the fetus. PaCO2 goes down during normal pregnancy and this respiratory alkalosis is expected. You should see PaCO2 of 30-32; if greater than 40mmHg your patient is tired and uterine flow is decreasing. This is bad news.
So your patient comes in and looks sick, do you have to change your workup? He suggests to order the same fluids, labs, most medications (except amiodarone, for instance) and give blood just as you would any other patient. CT the patient, if needed, because a sick mother implies a sick fetus. You must weigh cost benefit of all these interventions to favor mother’s survival.
How do you save a life in these critically ill patients immediately? Use this mnemonic, TOLD!
- Tilt the patient in left lateral decubitus
Tilt: After 20 weeks the uterus large and compresses IVC, this can cause a reduction of CO by about 30%. Put towels under right hip and tilt that patient quickly!
Oxygen: Try to avoid BiPAP and CPAP. These patients have increased progesterone, which means a weak lower esophageal sphincter. This translates to aspiration risk. You can try high flow humidified nasal cannula. This can go up to 60L of flow and give a baby dose of positive pressure (…a diet CPAP).
Lines: Avoid all femoral lines because a large uterus can compress those femoral and iliac veins. Place central lines above the diaphragm.
Dates/Delivery: Key date to remember is 24 weeks gestational age. This is a critical time for management of mother. Hypotension from compression of IVC starts here AND you have a potentially viable fetus. You can use the poor man’s method (fundal height at umbilicus=20 weeks, fundal height four fingers above umbilicus=24 weeks) or ultrasound to determine dates.
Don’t forget to call Ob/Gyn MD and RN for fetal monitoring and Pediatrics for care of the newborn.
So now you know the basics, what do you do with the patient literally ABOUT to crash?
Address the airway first. Everything that can go wrong with these patients will. No offense to interns, but this is not your intubation. Pregnant women have lower oxygen reserve from that diaphragm being compressed inferiorly. This will be a potentially difficult airway. So be prepared and get everything laid out.
- Do your preoxygenation if time permits and apneic oxygenation for everyone (15L nasal cannula free flow).
- Treat them like you do the obese airway. This is not meant to be offensive, but an obese patient the most similar anatomical equivalent The pregnant woman also has fat deposition in the neck, large breasts, limited neck mobility, and more mucosal edema. The ear must be at the sternal notch. Pillow and sheets will be your friend in this case.
- Load up the small tubes, move down to the 6.0 ETT and have a plan B-D.
- Vent settings still require Tidal Volumes to use IBW based on height, PEEP might be higher than standard 5 since you are fighting against the fundus on the diaphragm; but use oxygenation to dictate PEEP.
When your pregnant patient has a cardiac arrest focus on circulation: The ACLS algorithm is the same in regards to compression, defibrillation, and meds (except amiodarone which crosses fetal-maternal barrier and can cause iodine toxicity.
Tilting the mother makes it difficult to do adequate compressions. Instead, lay the patient on her back and push the uterus over.
Start the clock – you have 4 minutes once the mother arrests to perform a peri-mortem c-section (PMCS). Mother regains up to 80% CO back by removing fetus. Once you decide you must commit. There are case reports of people doing procedure after more than 4 minutes of CPR. During the procedure CPR must continue. Don’t forget to deliver the placenta and close the uterus and peritoneum. To recap on how to do PMCS, watch this video at emcrit.org.