An Emergent Cesarean Section in a Parturient with Acute Respiratory Distress Syndrome (ARDS)
Abstract Number: F-39
Abstract Type: Case Report/Case Series
The mortality rate for the parturient with Acute Respiratory Distress Syndrome is estimated to be 30-40%. The timing of delivery in the ARDS parturient is for fetal or maternal indications (1). Transport to the operating room has many complications for the ARDS parturient that have not been well-described. This case presents the challenges encountered during the transfer and intra-operative management of a parturient with ARDS.
Ms. B is a 30-year old G4P3 Caucasian female at 34 weeks gestation who was admitted for acute respiratory distress syndrome after inhaling toxic fumes from a mixture of bleach and ammonia which she sustained while cleaning her bathroom at home. She was intubated and ventilated using a low-volume ventilation strategy initially utilizing 60% inspired oxygen concentration, and fetal status was assessed using ultrasound examination as well as fetal heart tone monitoring. A few hours after admission, the patient was placed on 100% FiO2 with escalating PEEP to maintain a PaO2 of 60 mmHg. Approximately 16 hours after admission, she was placed on assist-control ventilation with a tidal volume of 380 mL, respiratory rate of 22, PEEP 18, FiO2 100%. Despite this maximal mechanical ventilation, the patient’s acid-base status continued to worsen, and the arterial oxygenation fell below 60 mmHg.
After a multi-disciplinary discussion with the intensive care, obstetric, obstetric anesthesia, and neo-natal intensive care teams, preparations were made to take the patient from the MICU to the operating room for an emergent cesarean section for the medical benefit of the mother. After arrival in the operating room, the patient immediately desaturated to an SpO2 of 67%. High peak pressures were noted, despite neuromuscular blockade and adequate anesthesia. Loud wheezing was appreciated upon auscultation bilaterally. Hand ventilation revealed poor lung compliance, and albuterol and steroids were given. Minimal improvement in oxygenation occurred, and the patient was placed back on the ICU transport ventilator. With this maneuver, the oxygen desaturation improved slightly over the next 20 minutes allowing surgery to commence. Intraoperatively, arterial blood gas revealed a worsening respiratory acidosis with severe hypoxemia. At delivery, the neonate had Apgar scores of 2, 3, and 3 at 1, 5, and 10 minutes respectively. After completion of surgery, the patient was not initially stable enough for transport back to the ICU given the PaO2 of 46 mmHG. Postoperatively, she developed atony in the ICU 6 hours post-operatively for which she received methylergonovine and multiple red blood cell transfusions.
Adverse events occur in up to 70% critically-ill patients during transport. Two issues that contributed to the respiratory decompensation in this patient are: the transport of the patient from the ICU to the OR, and the use of the OR ventilator instead of the transport ventilator.