BY KYLE NADEL & PAUL SILKA, MD
The older woman was short of breath and experiencing epigastric abdominal pain. She was an ex-smoker in her mid-70s with a past medical history of COPD, pulmonary fibrosis, breast cancer, and intermittent home oxygen. Her symptoms had started gradually a few hours earlier.
The patient's vital signs on arrival were a blood pressure of 122/80 mm Hg, heart rate of 101 bpm, respiratory rate of 42 bpm, and 91% SpO2 on 2 L/min via nasal cannula. She was tachypneic with accessory muscle use, and breath sounds were clear bilaterally but diminished on the left hemithorax.
The patient was promptly placed on continuous oxygen therapy via nonrebreather mask, and routine blood work was initiated. A chest x-ray revealed a left-sided pneumothorax, prompting the emergency physician to perform an anterior tube thoracostomy with a 19 French pigtail catheter placed in the fifth intercostal space at the midclavicular line. The pigtail catheter was attached to a Heimlich valve for air drainage without negative pressure or suction and secured with prefabricated adhesive dressing.
The patient was admitted to a post-procedure telemetry bed after a repeat chest x-ray demonstrated improvement of the left pneumothorax, but the patient developed worsening respiratory distress with oxygen saturation falling below 80% about seven hours after insertion of the catheter. (Figure 1.) Her heart rate also increased as she developed hypotension with absent breath sounds ipsilateral to the Heimlich valve and tracheal deviation contralaterally. Repeat chest x-ray revealed early left tension pneumothorax, and the next emergency physician on duty confirmed the x-ray findings of an acute left-sided tension pneumothorax because the pigtail catheter attached to the Heimlich valve had failed. A left lateral chest tube thoracostomy was performed using a 28French tube, which yielded immediate clinical improvement. The patient's vital signs stabilized, and a repeat chest x-ray demonstrated successful re-expansion of the left lung. (Figure 2.)
Figure 1: Chest x-ray showing left-sided tension pneumothorax seven hours after pigtail catheter and Heimlich valve insertion.
Figure 2: Chest x-ray indicating resolution of tension pneumothorax after a large bore chest tube thoracostomy.
Why did the treatment fail and precipitate the need for an emergent thoracostomy with a larger traditional chest tube? Was this the appropriate initial treatment for a pneumothorax? Was the failure of the initial apparatus predictable and a known complication?
The current literature indicates that treatment of a pneumothorax using a Heimlich valve is safe and definitive. (Ann Transl Med 2015;3:54; http://bit.ly/2GaSlMK; Br J Surg 2014;101:17; Ann Chir Gynaecol 1999;88:36.) The procedure must be performed properly, and the patient and care team must have adequate instruction on postprocedural maintenance. Some reports even argue that the Heimlich valve is more advantageous than thoracostomy because its portability allows for patient ambulation, which is believed to aid in lung re-expansion. (Thorax 1973;28:386, http://bit.ly/2WG7NWg; Ann Transl Med 2015;3:54, http://bit.ly/2GaSlMK; Br J Surg 2014;101:17.)
The efficacy of the treatment has been established, but a number of case studies reported a spontaneous tension pneumothorax following initial treatment with a pigtail catheter attached to a Heimlich valve. Existing reports implicate tension pneumothorax resulting from inadvertent dislodgement, patient tampering, malpositioned catheter, flutter occlusion due to exudation, and catheter kinking. (Thorax 1973;28:386, http://bit.ly/2WG7NWg; AJR Am J Roentgenol1992;158:763, http://bit.ly/2MRpa22; Chest 1988;94:55, 1998;113:838, 1990;97:759.)
The Heimlich valve may also fail if the atmospheric pressure is lower than that of the intrapleural cavity. (Ann Transl Med2015;3:54; http://bit.ly/2GaSlMK.)
The Heimlich valve was initially successful in partial lung re-expansion in this case, though a spontaneous tension pneumothorax ensued, requiring emergent chest tube thoracostomy. The chest x-rays revealed that the failure was caused not by the Heimlich valve itself, but the attached pigtail catheter, which evidently became kinked in the thoracic cavity. Given the narrow lumen of the pigtail catheter, even a small kink prevents air from passing, making it useless in lung re-expansion. Catheter kinking may have occurred because of poor placement, though was more likely induced by inadvertent patient movement or tampering.
Despite the adverse complication experienced in this case presentation, the literature along with our clinical experience support the use of a small-caliber pigtail catheter and a Heimlich valve. They are efficacious and relatively well tolerated in treating nontraumatic pneumothorax. Disposition of these patients, whether to the hospital or discharge, must include meticulous care instructions calling out the risk for developing a tension pneumothorax and instructions on how to proceed should it occur.
Mr. Nadel has a master's degree in nutrition from Columbia University and is currently a research associate, and Dr. Silka is an adjunct associate professor of emergency medicine, both at LAC+USC.