Acute Hypercapnic Respiratory Failure in a Patient with Esophageal Adenocarcinoma
American Journal of Respiratory and Critical Care Medicine
Introduction Acute Hypercarbic Respiratory failure (AHRF) is commonly due to COPD and narcotic or sedative drug toxicity. AHRF as a presenting feature due to muscle weakness is much less common. Case Description A 74-year-old male with history of Esophageal Adenocarcinoma (EA) diagnosed three months before presentation, complained of a 4-weeks history of progressive dyspnea. Initial evaluation was significant for lethargy and increased work of breathing. A venous blood gas revealed pH of 7.23, PCO2 of 94 and Bicarbonate of 25. Chest X-Ray and CT scan of chest showed bilateral pleural effusions and bibasilar atelectasis. He was started on Bilevel Positive Airway Pressure, nevertheless he eventually became fatigued and developed worsening hypercarbia. He underwent endotracheal intubation and was transferred to the Medical Intensive Care Unit (MICU). After three days into his hospitalization, the focus switched at looking for neuromuscular disorders leading to his AHRF. A Magnetic Resonance of the brain, Electromyography (EMG) and Nerve Conduction Studies (NCS) resulted inconclusive. On the 6 thday of hospitalization, the Acetylcholine Receptor Modulating and Binding Antibodies resulted positive, providing a diagnosis of MG. The patient was started on Pyridostigmine and completed a 5-day course of Intravenous Immune Globulin resulting in overall improvement of his respiratory status. On the 14th day of hospitalization he was successfully extubated and transferred to a step-down unit on day 16. Four days after, after complete resolution of the clinical derangements, the patient was started on Prednisone, with plans for a 3-month taper. Discussion MG, once considered a disabling and even fatal disorder is now effectively managed with current therapeutic modalities. The novelty of this case is threefold First, AHRF secondary to respiratory muscle weakness is quite unusual as it is estimated to be the culprit 1.5 to 4% of the times (MG itself only 0.8 to 2.8%). It is necessary to always consider this etiology. Secondly, to our knowledge, MG has never been associated with EA before, It is uncertain but very likely that EA lead to late-onset MG in our patient, making it crucial to be cognizant about this possible association. Lastly, single-fiber EMG is considered the most sensitive test for diagnosis of MG, it is imperative to consider all the circumstances that could lead to an inconclusive result and not completely disregard this entity based only on this test; in our case, electrical interference with MICU equipment was the reason.
Figueroa Rodriguez F, Savedchuk S, Schloop M, Dalal BD. Acute hypercapnic respiratory failure in a patient with esophageal adenocarcinoma. American Journal of Respiratory and Critical Care Medicine 2019;199:A1770