A 25-year-old female with amitriptyline overdose developed wide-complex tachycardia, aspiration pneumonia, and ARDS, successfully managed with sodium bicarbonate and lung protective ventilation.
Case Report (n=1)
This case highlights the successful management of amitriptyline overdose complicated by aspiration pneumonia and ARDS using sodium bicarbonate and lung protective ventilation.
Abstract We present here a case highlighting the amitriptyline toxidrome, further complicated by aspiration pneumonia and progression to acute respiratory distress syndrome (ARDS). Case Presentation A 25-year-old female with medical history of seizures, alcohol use, cyclic vomiting syndrome, hypothyroidism, tachycardia, migraines, and anxiety, presented to the hospital following a suspected overdose. Home medications included amitriptyline, lamotrigine, mirtazapine, sertraline, ondansetron, norethindrone, metoprolol, and levothyroxine. On arrival the patient was unresponsive with muscle spasms concerning for seizure, prompting intubation, levetiracetam load, and continuous midazolam infusion. ECG demonstrated wide-complex tachycardia with prolonged QT interval; chest x-ray identified a dense left lower lung consolidation, with bedside bronchoscopy notable for copious thick, white secretions that were therapeutically aspirated. The patient was admitted to the ICU on continuous EEG. Midazolam was continued for possible seizures or serotonin syndrome, and sodium bicarbonate was administered for suspected amitriptyline overdose (later confirmed by blood amitriptyline level). Empiric antibiotics were started for aspiration pneumonia and adjusted appropriately when respiratory cultures resulted positive for Haemophilus influenzae. Repeat chest imaging indicated progression to ARDS and lung protective strategies were initiated, including lower tidal volumes, high PEEP, inhaled nitric oxide, and paralysis. Prone positioning and VV ECMO cannulation were considered for refractory hypoxemia, but were ultimately not required. The patient was extubated on hospital day 12, and discharged to a subacute rehabilitation facility. Discussion Tricyclic antidepressant (TCA) use has fallen out of favor, largely due to the lethality of TCA overdose. The TCA toxidrome may include prolongation of the PR, QRS, and QT intervals--mediated by interference with cardiac sodium channels--and either bradyarrhythmia from sinus node blockage or tachyarrhythmia triggered by anticholinergic effects. As TCA poisoning is variable in presentation, it should be considered in all patients presenting post-overdose with arrhythmia. Treatment is sodium bicarbonate: the additional sodium maximizes remaining function of cardiac ion channels, while bicarbonate-induced serum alkalinization converts TCAs to their less-active, nonionic form. As in this case, a common complication of overdose is aspiration, often leading to pneumonia. Patients post-aspiration are comparatively high risk for progression to ARDS--in addition to the infectious exposure, chemical pneumonitis from gastric acid aspiration promotes development of ARDS. Treatment for ARDS varies by cause, but a commonality is lung protective ventilation strategy, with adjuncts including inhaled nitric oxide and paralysis. Appropriate respiratory support is paramount in temporizing the patient while interventions such as antibiotics help resolve the underlying cause of ARDS. This abstract is funded by: None
Sherman et al. (Fri,) conducted a case report in Amitriptyline overdose, aspiration pneumonia, ARDS (n=1). Sodium bicarbonate, lung protective ventilation, antibiotics was evaluated. A 25-year-old female with amitriptyline overdose developed wide-complex tachycardia, aspiration pneumonia, and ARDS, successfully managed with sodium bicarbonate and lung protective ventilation.