Carbs aren't always bad....Starvation ketoacidosis in a parturient with pneumonia.
Abstract Number: T-15
Abstract Type: Case Report/Case Series
Introduction: Anesthesiologists increasingly work as part of a multidisciplinary team caring for medically complex parturients. This requires a greater awareness of medical issues. Metabolic disease was cited in the latest CMACE as one of the causes of indirect maternal mortality.
Starvation ketoacidosis occurs most commonly in the third trimester. Abrupt reduction in carbohydrate intake, coupled with placentally mediated increased insulin resistance, can lead to alternative metabolic pathway activation and severe ketoacidosis with potential for maternal and fetal morbidity. Increased awareness and appropriate treatment of this phenomenon can reduce the risk to both mother and fetus. We present a case of starvation ketoacidosis related to pneumonia.
Case report: A 27 year old G10P1 presented at 36+6 weeks with a 24 hour history of vomiting and anorexia for a week. She complained of recent fever, reduced fetal movements and abdominal pain. She was febrile, tachycardic, tachypnoeic and hypoxic. Arterial blood gas analysis showed metabolic acidosis with pH 7.23 and BE -22, lactate 1.1mmol/l and blood glucose 3.4mmol/l. Blood ketones were 4.6mmol/l. The patient had a radiologically confirmed pneumonia. Alongside fluid resuscitation and antibiotic administration, treatment was with 20% intravenous dextrose and if BMs >8, an insulin infusion. The patient was admitted to the intensive care unit for observation and ongoing fetal monitoring. 7 hours after treatment commenced, the acidosis markedly improved and within 24 hours had completely resolved with normal blood ketones. The patient was discharged on antibiotics and delivered spontaneously at 38 weeks.
Discussion: Starvation ketoacidosis is rare and may not be familiar to the labour ward anesthesiologist. In the absence of glucose as a substrate, there is a switch to free fatty acid production, but accumulation of ketones can lead to metabolic acidosis. Placental glucagon and human placental lactogen cause insulin resistance and therefore increase susceptibility to starvation ketoacidosis in pregnancy, particularly in the third trimester. Diagnosis is made on history, examination and investigations. Ketosis should be considered in the presence of an increased anion gap and normal lactate. Blood glucose should exclude diabetic ketoacidosis. Treatment focuses on providing carbohydrate as a substrate and insulin if needed, alongside necessary fluid resuscitation.
Early recognition is paramount to reduce the risk to both the mother and fetus. In many cases, delivery of the fetus and placenta is required to overcome the acidosis. This case demonstrates that timely management with carbohydrate and insulin can arrest ketogenesis and avoid the need for early delivery.
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