Novel electrocardiographic changes associated with iatrogenic pneumothorax.

A56-year-old woman (height 165 cm, weight 65 kg) was admitted to the hospital because of a 2-day history of epigastric pain and emesis. Two weeks prior to admission, she had a Billroth II with Roux-en-Y procedure for stomach stricture and biliary reflux. Her medical history was significant for 1 episode of atrial fibrillation many years previously, osteoporosis, bilateral hip replacements, and gastric ulcer surgery. Drug therapy at the time of admission included simethicone 80 mg/d, rabeprazole 10 mg/d, and as-needed doses of clonazepam for anxiety and of acetaminophen. At admission, the patient’s blood pressure was 120/70 mm Hg and her heart rate was 90/min and regular. The physical examination was notable for facial and conjunctival pallor. Mucous membranes were dry. The patient’s abdomen was distended and tender to palpation in the upper quadrants. Bowel sounds were decreased. Her extremities were cool and her peripheral pulses were weak. The abdominal surgical wound was healing. The patient denied any cardiopulmonary symptoms and the results of her neurological examinations were normal. The patient’s white blood cell count was slightly elevated at 10.9 x 109/L, and her hemoglobin level was 112 g/L. Her serum level of creatinine was elevated at 110 μmol/L (normal 50-100 μmol/L). International normalized ratio, partial thromboplastin time, and serum levels of electrolytes, amylase, and troponin T were all normal. Results of a urine screen indicated no signs of infection. The serum level of myoglobin was elevated at 240 μg/L (normal 24-58 μg/L). A 12-lead electrocardiogram (ECG) obtained with the patient supine showed normal sinus rhythm (Figure 1). The patient was moderately dehydrated, and intravenous fluid replacement was deemed necessary. Efforts to obtain peripheral venous access were unsuccessful. Air was aspirated during an attempt to cannulate the left subclavian vein for central venous access. Subsequently, a catheter was inserted in the left internal jugular vein. Ten minutes after insertion, the patient began experiencing left-sided, pleuritic chest pain with no radiation or concomitant nausea, diaphoresis, or palpitations. Vital signs, including oxygen saturation during delivery of oxygen at a rate of 3 L/min via nasal prongs, were stable except for tachycardia of 126/min. Lack of air entry and hyperresonance were detected over the left side of the thorax. A 12-lead ECG obtained with the patient supine showed ST-segment elevation in leads II, III, aVF, V5, and V6; increased R wave in leads III and aVF; and inversion of the QRS complex in aVL (Figure 1). Findings in modified right-sided leads were normal. Because the f indings were suggestive of acute myocardial infarction, aspirin 160 mg and metoprolol 25 mg were administered. Pain was treated with morphine 2.5 mg intravenously. Metoclopramide 10 mg was given intravenously along with morphine to prevent nausea. Chest views were added to the abdominal computed tomography that previously had been ordered to detect any intra-abdominal abnormalities. The images of the chest confirmed a 70% left-sided pneumothorax, with the heart in anatomical position (Figure 2). An obstruction of the small bowel also was present. A chest tube with a one-way valve was placed to relieve the pneumothorax. Immediately after decompression of the pneumothorax, the patient’s pleuritic chest pain resolved. Chest radiographs and a 12-lead ECG obtained 1 hour after decompression revealed a completely reexpanded lung and resolution of ECG abnormalities (Figure 1), with the central venous catheter in good position in the superior vena cava. Serial measurements