Case Study: The Nightmare Patient – Hypoxic Status Seizure
Case:
This podcast lays out the case of a 36 year old female patient that suffered collapse and refractory grand mal seizure while at home. The patient was 2 weeks postpartum and had a history of preeclampsia during her pregnancy. Family stated she had a C-section during active labor because of minor complications associated with the preeclampsia. During the patients continued seizure activity she vomited multiple times prior to EMS arrival. This complicated her airway management, as the responding EMS agency didn’t have the ability to perform rapid sequence intubation. Subsequently she was transported to the local ED and intubated by the ER physician.
Disease physiology:
This disease process is often forgotten when providing education to our providers. We get so focused on cardiac, trauma and other cool things, that we forget diseases associated with OB emergencies. With that being said, preeclampsia is the leading cause of maternal and fetal mortality worldwide. Preeclampsia is defined as a disease process that exhibits hypertension and proteinuria that starts after the 20th week of gestation [1]. These presentations will often resolve after delivery. However, often times the preeclampsia will progress during delivery or during the postpartum phase with a full eclampsia event with associated intracerebral hemorrhage, pulmonary edema, and respiratory and hepatic failure [1].
Preeclampsia is said to be related to some type of immunological element that is not fully understood, but it’s thought to be secondary to some type of abnormality of placentation and placental hypoxia [2]. In most cases the mother will have eclampsia during the delivery process. Management includes delivery of the placenta after full stabilization of the mother.
Pulmonary edema is a common occurrence in-patients with pre-eclampsia, with approximately 70% of cases happening postpartum. The acute hypertensive crisis that precipitates the acute pulmonary edema may occur through sympathetic nervous system activation, causing acute venoconstriction and vasoconstriction, which leads to increased afterload and redistribution of fluid from the peripheral circulation to the pulmonary vessels [2]. Many of these mechanisms are still unknown, however, women suffering from pre-eclampsia go from increased cardiac output and SVR to low cardiac output and high SVR. This in turn causes left ventricular diastolic dysfunction and progresses the incidence of pulmonary edema. The incidence of pulmonary edema should immediately tell you your patient is gravely sick. This presentation alone is a strong indicator of significant morbidity and high mortality.
HELLP Syndrome (hemolysis, elevated liver function tests, low platelet counts) is another complication to preeclampsia and eclamptic events. Although incidence is low at 0.2-0.6 %, high morbidity and mortality is common [1]. Treatment for the pre-hospital provider is limited to magnesium sulfate administration for potential seizures. Fluid restriction and assessment for potential DIC should be ongoing.
Treatment:
The goals of treatment will be encompassed around management of the airway by advanced techniques if needed. Intubation and mechanical ventilation will often be warranted. Patient’s suffering from pulmonary edema with refractory hypoxia will need modes of ventilation that optimize oxygenation. High PEEP, > 10 cmH20, may be needed with severe presentations. SIMV – pressure may assist with oxygenation diffusion due to the modes decelerating flow pattern. Always start in volume however and identify your Peak Inspiratory Pressure (PIP) and Plateau Pressure (Pplat). Care should be taken to reduce Pplat < 30 cmH20.
Magnesium sulfate is the top treatment of choice because of its excellent seizure properties. It’s been shown to reduce the seizure threshold by 50%. Treatment of hypertension with Hydralazine or Labetalol is most appropriate. Hydralazine is first line with pregnancy-induced hypertension, however Labetalol 10 mg IVP, (max dose of 20 mg) is the treatment of choice for hypertension associated with an eclamptic event. Goal will be to reduce systolic < 180 and diastolic < 110 mmHg.
This case is multifaceted and really takes you down multiple pathways. Remember to always assess your patient thoroughly and go down your differential diagnosis pathway. Start with airway and then move through your normal progression of treatment. Remember, PEEP in this case made the biggest difference with her hypoxia and overall hemodynamic status. Early identification and understanding that PEEP >10 cmH20 may be warranted will give you time to make good decisions and confer with your partner, referring physician or medical director if needed.
Articles for Review
1. Gary, S. (2014, April 2014). Preeclampsia: pathophysiology, old and new strategies for management. European Journal Of Anaesthesiology, 31(4), 183-189. http://dx.doi.org/10.1097/EJA.0000000000000044
2. Ghassan M. Hammoud M.D., MPH and Jamal A Ibdah M.D., Ph.D., AGAF. (2014, 26 Sep 2014). Preeclampsia-induced Liver Dysfunction, HELLP syndrome, liver of pregnancy. Clinical Liver Disease, 4(3), 69-73. http://dx.doi.org/10.1002/cld.409
3. Acute pulmonary edema in pregnant women – http://onlinelibrary.wiley.com/doi/10.1111/j.1365-