Additive effect of propofol and fentanyl precipitating cardiogenic shock
A 34-year-old woman presented with complaints of umbilical hernia and had no secondary infection on clinical examination. The surgery was performed under conscious sedation and analgesia procedure which is routinely preferred by the anesthetists for minor surgeries. The patient experienced sudden, severe hemodynamic deterioration after undergoing this minor surgical procedure. Spontaneous breathing was maintained by continuous infusion of propofol at a rate of 100 μg/kg/min to achieve conscious sedation after administering fentanyl 100 μg intravenously. During surgery, the patient remained hemodynamically stable. Patient had nausea and vomiting in the early postoperative period, which were treated with 4 mg of intravenous ondansetron. A few minutes later, the patient experienced hemodynamic instability with sinus tachycardia and hypotension. Her heart rate was 122 regular beats/minute, and the blood pressure was 50/30 mmHg. The oxygen saturation had decreased to 80% as recorded by pulse oximetry, despite oxygen supply through face mask. She was immediately treated with intravenous dopamine and dobutamine as well as with ventilator support due to acute respiratory failure. The arterial gasometry showed oxygen pressure 40 mmHg and carbon dioxide pressure 49 mmHg; the electrocardiogram monitor showed sinus tachycardia. The signs of heart failure (HF) were found in the bedside digital X-ray of chest and emergency transthoracic echocardiography (TTE) revealed severe biventricular dysfunction with global hypokinesia. The LVEF was 42%. Coronary angiography showed no coronary lesions. An intra-aortic balloon pump was introduced for counterpulsation. The repeat TTE revealed LVEF 32% and a left ventricular extracorporeal membrane oxygenation (ECMO) device was inserted to assist the impaired clinical course of the patient. The LVEF gradually improved and on the 5th postoperative day the ventilatory support and circulatory perfusion assistance were removed. Troponin T and C reactive protein levels remained within normal limits. The other routine investigations like chemistry panel, complete blood cell count, and coagulation profile were within normal limits. The serology battery for myocarditis, blood cultures, urine cultures, and cytotoxic antibodies were found insignificant. An endomyocardial biopsy was not performed because of its low diagnostic yield. Three weeks later, a new TTE showed a non-dilated left ventricle, absence of segmental contractility alterations, and an LVEF in the normal range. She was reviewed for 6 months in out-patient department and was found asymptomatic and required no further treatment.