A 65-year-old female was transported to the emergency department (ED) at approximately 2:00 AM following a witnessed cardiac arrest. According to the patient’s husband, she had been asleep in bed when she awoke suddenly, sat upright, and reached for her albuterol inhaler before “collapsing.” He found her to be pulseless and initiated cardiopulmonary resuscitation (CPR) while placing a call to emergency medical services (EMS). On EMS arrival, the patient was unresponsive and continued to receive CPR. She was intubated in the field using a size 7.0 endotracheal tube. Her initial rhythm was pulseless electrical activity (PEA), but she converted to normal sinus rhythm after receiving 1mg of epinephrine intravenously and 15 total minutes of CPR. No further history was available.\nPer her husband, her past medical history was notable for “thyroid problems.” Her only medications were an albuterol inhaler, recently prescribed by her primary physician, and a multivitamin. She had no known drug allergies. On social history, the patient was not known to drink alcohol, smoke cigarettes, or use other substances. A family medical history and review of systems could not be obtained due to the acuity of her condition.\nOn examination, the patient was an obese female, intubated, and unresponsive. Her temperature was 37.1 degrees Celsius, blood pressure was 97/65 millimeters Hg, heart rate was 75 beats per minute (bpm). Her body mass index was estimated at 32. She was initially receiving assisted ventilation by EMS, but on examination in the ED she was found to have a spontaneous respiratory rate of 12 breaths per minute with an oxygen saturation of 98% on 40% fraction of inspired oxygen. Her head was atraumatic and normocephalic. Her pupillary exam showed mid-dilated symmetric pupils with sluggish reactivity to light. There was no hemotympanium or Battle’s sign. She had no apparent facial droop. An oral endotracheal tube was in place, confirmed with radiography and audible bilateral breath sounds. She had a full, supple neck without palpable masses, but additional exam was limited by body habitus. On cardiopulmonary exam, her lungs were clear to auscultation bilaterally and her heart had a regular rate and rhythm with no murmurs, gallops, or rubs. The patient’s abdomen was soft and nondistended with normal bowel sounds. On neurologic exam, her Glascow Coma Scale was 3T. She had diffusely decreased muscle tone, and 1+ patellar and brachioradialis deep tendon reflexes. Her musculoskeletal exam was unremarkable for deformity, erythema, or edema. Skin exam did not show any rashes, wounds or other lesions.\nInitial electrocardiogram (ECG) () showed normal sinus rhythm at a rate of 70 bpm, normal axis, normal intervals and no pathologic t-wave inversions or ST-segment changes. A complete blood count and complete metabolic panel were done (). Additional laboratory tests, including thyroid studies, were unremarkable except for an elevated lactic acid of 6.9 millimoles/liter (L) (). A point-of-care echocardiogram was performed, which demonstrated grossly normal heart chamber sizes and systolic function with no pericardial effusion (). A point-of-care ultrasound of the abdomen and thorax was negative for any intra-abdominal free fluid. There was bilateral lung sliding present and no B lines. An anterior to posterior chest radiograph (CXR) is shown in .\nThe etiology of the patient’s cardiac arrest was unknown until a further diagnostic test was performed that revealed the diagnosis.
Case 2 involved a 65-year-old man with no known medical history and a diagnosis of rectal cancer. He had a BMI of 20.3kg/m2, an ESS score of 2, and was scheduled for a laparoscopic abdominal surgery. One day prior to the surgery, he performed an apnea test via ApneaLink™ between 00:00 and 06:00 am, which yielded the following results: AHI: 22/hr, AI: 0/hr, HI: 22/hr; ODI: 3/hr, min. SpO2 86%, and max. HR: 108/min. A decision was made for postoperative ICU follow-up of the patient.\nFollowing the two-hour long surgery, the intubated patient was admitted to the ICU, where he was extubated at the second hour and given O2 mask support (5L/min). The results of the apnea test conducted on the operation day between 00:00 and 06:00 am were as follows: AHI: 38/hr, AI: 0/hr, HI: 38/hr, ODI: 1/hr, min. SpO2: 81%, and max. HR: 101/min. It was decided that he should be scheduled for postoperative non-invasive mechanical ventilation (NIMV) support (Table ).