Benefits of thrombolytics in prolonged cardiac arrest and hypothermia over its bleeding risk
A 52-year-old non-smoking Caucasian male, who is allergic to shrimps, presented to the emergency room (ER) after he was found unconscious in the bathroom. At 6 days before presentation, patient had symptoms of severe cough with streaks of blood and dyspnea on exertion and was treated with azithromycin antibiotic for presumed upper respiratory tract infection. The day before presentation, patient's symptoms of cough and dyspnea started getting worse. Patient reported taking benzonatate antitussive, which caused tingling and numbness around his mouth and cheeks, which resolved spontaneously after 30 min. Patient did not report of hives, swelling of the face or tongue and difficulty in swallowing. Subsequently, patient got extremely agitated and short of breath leading to state of unconsciousness. Emergency medical services were activated, 100% oxygen was initiated and patient was transferred to our ER.\nIn the ER, patient presented with grey colored skin and symptoms of severe dyspnea. As per the patient's wife, he had no calf pain and/or swelling recently. There were no recent hospitalizations, prolonged immobilization or history of pulmonary embolism (PE) and/or deep vein thrombus (DVT). He had no other medical procedures and/or surgeries performed in the recent past. Patient's father has a history of PE secondary to extensive airplane travel and stroke. Patient has no history of familial clotting disorders. Consequently, patient developed complete heart block and received intravenous atropine and epinephrine. An electrocardiogram showed a right bundle branch block and ST-segment elevations in the inferior leads with elevated troponins of 13.5 ng/ml (normal <0.03 ng/ml). Cardiac monitor showed pulseless electric activity and patient was intubated and cardiopulmonary resuscitation (CPR) was initiated immediately. The cardiac arrest was presumed from ST elevation myocardial infarction and the patient was transferred to cardiac catheterization laboratory. Patient intermittently remained in cardiac arrest requiring intra-aortic balloon pump and temporary pacemaker. Short episodes of CPR were performed. Cardiac catheterization showed non-obstructive coronary arteries and a hyper-dynamic left ventricle. Patient's blood pressure remained low and so patient was continued on epinephrine, dopamine drips. Patient was then transferred to the intensive care unit and he remained intubated with mechanical ventilation and ongoing CPR. On physical examination, the patient was noted to have respiratory rate of 30 breaths/min, fixed and dilated pupils of 7 mm and endotracheal tube in place. His neck was supple without jugular vein distention. Chest examination revealed distant lung sounds, with no wheezing. Cardiac auscultation was tachycardia with no murmurs, gallops and rubs. On neurologic al examination, the patient's Glasgow coma scale was <9 with no gag reflex and response to Babinski. Rest of the examination was unremarkable. Laboratory data revealed white cell count of 11.7 × 109/L (normal 4.3-10 × 109/L) with the normal differentials, creatinine of 2.4 mg/dl (normal 0.7-1.3 mg/dl), ionized calcium of 4.0 mg/dl (normal 4.6-5.1 mg/dl) bicarbonate of 15 mmol/L (normal 22-30 mmol/L), serum osmolality of 322 mOsm/kg (275-295 mOsm/kg), anion gap of 21 mmol/L (normal 8-16 mmol/L) and lactic acid of 16 mmol/L (normal 0.7-2.1 mmol/L) and D-dimer of 6.68 μg/ml (normal <0.49 μg/ml). Other blood cell counts, liver function tests, alcohol, salicylate, methanol levels and urine toxicology screen were unremarkable. An arterial blood gas showed a pH of 6.8, pCO2 of 70 mmHg, pO2 of 90 mmHg on mechanical ventilation, consistent with mixed respiratory and metabolic acidosis. Electrocardiogram showed sinus tachycardia with occasional premature ventricular complexes and right bundle branch block. Chest X-ray showed bilateral basilar infiltrates and cardiomegaly. Stat bedside echocardiogram revealed moderate hypokinesis and enlargement of the right ventricle. Patient's clinical symptoms, laboratory investigations, negative cardiac catheterization of obstructive coronary arteries, electrocardiogram showing sinus tachycardia and echocardiogram proving hypo kinesis and enlargement of right ventricle suggested presumed diagnosis of PE causing cardiac arrest. At the same time, alteplase, tissue plasminogen activator (tPA) was administered immediately with the dose of 0.6 mg/kg over 2 min in a bolus form and heparin drip was started. During the course of the intensive care stay, patient was treated with hypothermic protocol for cardiac arrest with no bleeding complications. Intravenous sodium bicarbonate and calcium chloride were given, cardiac arrest was eventually terminated and patient got extubated. The blood pressure got stabilized and dopamine, epinephrine drips were stopped. Furthermore, intravenous hydrocortisone, benadryl was administered for possible anaphylactic reaction.\nSubsequently, patient rapidly improved with decreased requirement of oxygen. Repeated arterial blood gases within an hour were improved and revealed pH of 7.15, pCO2 of 47 mmHg and pO2 of 404 mmHg. Repeated echocardiogram noted normal size and function of the right ventricle. Venous Doppler's of the lower extremities showed DVT in the left distal femoral vein, gastrocnemius, peroneal vein and normal right lower extremity. The inferior vena cava filter was placed to prevent further occurrence of life-threatening clots or pulmonary embolus and heparin drip was continued. The renal failure secondary to the cardiogenic shock improved with 2 mg of bumetanide, oral diuretic therapy. During the hospital course, heparin was discontinued due to patient's low platelet count and positive heparin induced thrombocytopenia panel. Rivaroxaban, the oral anticoagulant was initiated and patient was transferred to floor with oxygen saturation of 95% on room air. On the medical floor, patient was walking and moving around, could talk in full sentences, was able to feed himself. Within 3 days of the hospital stay, he showed remarkable clinical and functional improvement and was discharged to home in a stable condition.