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Dr. Baumann is Associate Professor of Medicine, Division of Pulmonary and Critical Care Medicine, University of Mississippi Medical Center.
Correspondence to: Michael H. Baumann, MD, FCCP, Associate Professor of Medicine, Division of Pulmonary and Critical Care Medicine, University of Mississippi Medical Center, 2500 North State St, Jackson, MS 39216; e-mail: mbaumann{at}medicine umsmed.edu
COPD likely remains the most common cause of secondary spontaneous pneumothoraces.1 However, AIDS-related pneumothoraces, particularly those associated with Pneumocystis carinii pneumonia (PCP), might be the leading cause of secondary spontaneous pneumothoraces in the urban setting.2 Wait and Estrera2 noted that 36% of secondary spontaneous pneumothoraces in patients admitted to Parkland Memorial Hospital (Dallas, TX) are due to AIDS, with the majority from underlying PCP; COPD accounted for only 13% of secondary spontaneous pneumothoraces in patients admitted to the hospital. Factoring out procedure- and volutrauma (mechanical ventilation)-related pneumothoraces, a secondary spontaneous pneumothorax may complicate 1.6 to 2.0% of AIDS patients.3 4 AIDS-related pneumothorax mortality ranges from as low as 10 to 18%3 4 to as high as 50%.5 Volutrauma-related pneumothoraces in AIDS patients are also common. In one series,3 15 of 50 AIDS-related pneumothoraces (30%) were due to volutrauma. This type of pneumothorax may carry a high mortality (100%), and PCP is also frequently implicated.3 Hence, a spontaneous pneumothorax may represent a valid reason to evaluate the HIV status of a patient and to search for PCP in a known HIV-positive patient.
The often-limited survival prospect of patients with an AIDS-related pneumothorax is compounded by the patients’ marked immunosuppression and the problematic bronchopleural fistulae that often accompany PCP-related secondary spontaneous pneumothoraces. Given this patient scenario, the least invasive, safest, therapeutic option offering the greatest success with the shortest length of stay seems advisable.
Driver et al6 first reported such a therapeutic option utilizing a Heimlich valve to facilitate outpatient management of two patients with AIDS-related pneumothoraces. Trachiotis et al7 built on this concept in 1996. Incorporating the Heimlich valve, Drs. Vricella and Trachiotis again offer support for the use of a relatively noninvasive approach to the management of advanced AIDS-related pneumothoraces in this edition of CHEST (see page 15). Their therapeutic algorithm strategically integrates the Heimlich valve into failed conventional therapeutic approaches in patients with a persistent bronchopleural fistula.
Forty-seven patients with advanced AIDS (CD4 counts < 100) with 59 pneumothoraces were retrospectively assessed. Seventy percent of the patients had prior or current PCP. The most encouraging finding in patients managed with a Heimlich valve was a shorter mean length of stay after conversion to the valve compared to those managed conventionally by chest tube placement and thoracotomy. Mortality was also higher in those conventionally managed (29.7%). Heimlich valve utilization in these advanced AIDS patients with pneumothorax is truly a case of "less being more": more days out of the hospital for terminal patients with the relative freedom afforded by a Heimlich valve.
Serious complication due to inappropriate outpatient Heimlich valve care mandates clear patient instructions on its care8 and close follow-up. Drs. Vricella and Trachiotis do not specifically note this key aspect of Heimlich use or that any drainage of viscous material through the chest tube is a relative contraindication to conversion to a Heimlich valve given concerns for developing valve occlusion.8
Patients discharged with a Heimlich valve in the study by Vricella and Trachiotis had a 100% resolution of their pneumothorax, enabling removal of the drainage catheter and valve. Two of these 10 patients died during the 60-day follow-up period (20% mortality), a rate nearly 10% less than the in-hospital mortality for conventional therapy. No statistical comparison is provided, but with the limited number of patients studied, a ß error would have been likely. Arguably, the patients discharged with a Heimlich valve, having endured failed initial conventional therapy, are a self-selected group of better survivors despite the difficulty of continued bronchopleural fistulae. In addition to a seemingly improved short-term mortality, the greater resolution of pneumothoraces with the Heimlich valve over conventional therapy (100% vs 55%, respectively) may also reflect an inadvertent selection bias in patients receiving a Heimlich valve; perhaps these patients were suffering less advanced AIDS despite patients having similar CD4 counts. However, a comparable mortality rate (20%) to that reported by others (10 to 18%)3 4 likely indicates a similar level of illness in the present study patients compared with earlier reports of AIDS-related pneumothoraces.
Criticism of the article by Vricella and Trachiotis is related to its retrospective design. Vricella and Trachiotis compound this by missing the opportunity to complement an earlier retrospective comparison of 76 AIDS patients by Metersky and colleagues,9 where 35 AIDS patients with 45 AIDS-related pneumothoraces, most with proven or presumed PCP, are compared to 41 AIDS patients with no secondary pneumothoraces. A multivariate analysis by Metersky et al9 reveals that cigarette smoking and prior aerosolized pentamidine treatment are independently associated with pneumothorax. Importantly, given the common corticosteroid use in the presence of PCP, corticosteroids are not associated with an increased risk of pneumothorax but with an increased likelihood of a prolonged bronchopleural fistula.9 Vricella and Trachiotis present no comparative control group; such an effort could have altered the compelling conclusions of Metersky et al,9 especially with regard to the detrimental effect of corticosteroids.
Not answered by this study, or any study to my knowledge, is the success and safety of using a drainage catheter and Heimlich valve as initial therapy in AIDS-related spontaneous pneumothorax. Patients in the advanced stages of AIDS with no contraindications might be excellent candidates for initial placement of a drainage catheter and Heimlich valve and subsequent close outpatient monitoring. Complicating problems such as underlying PCP could also be managed in an outpatient setting. Patients would require careful selection, monitoring, and informed consent of alternative options and risks. Additionally, as in the management of selected patients with primary spontaneous pneumothorax and COPD-related secondary spontaneous pneumothorax, incorporation of a drainage catheter and Heimlich valve might be appropriate for AIDS-related pneumothoraces in patients with less advanced AIDS. However, recurrence rates as noted by the work of Vricella and Trachiotis and others2 9 are at least 34% in AIDS-related pneumothoraces, and discharge with a Heimlich valve misses the opportunity of recurrence prevention. Such recurrence prevention considerations are particularly relevant in patients with a longer life expectancy.
Other non-Heimlich valve options for management of AIDS-related pneumothoraces are noted in both the present study and in the study by Metersky et al.9 Both stipulate the initial use of tube thoracostomy. Metersky et al9 aptly pointed out the limited chance of spontaneous resolution (< 9%) of an AIDS-related pneumothorax; simple observation plays no role in these patients, and tube thoracostomy is a must. Based on the initial failure of tube thoracostomy, other treatment options, including tube-directed sclerosis and surgery, should not be abandoned due to potential enthusiasm for Heimlich valve use. This is particularly true of AIDS patients without advanced disease. Metersky et al9 note successful sealing of an air leak in nearly 40% of AIDS-related persistent bronchopleural fistulae treated with chemical pleurodesis. The current study notes only 2 of 9 patients (22%) successfully achieving pneumothorax resolution with sclerosis; it is not clear if this success included sealing potential air leaks. However, prompt resolution of a pneumothorax with a tube thoracostomy affords an ideal opportunity for recurrence prevention using any number of sclerosing agents, hence obviating the need for surgical prevention measures. None of the patients in the Metersky et al9 series treated with chemical pleurodesis had a pneumothorax recurrence, but the duration of follow-up is not clearly defined.
Wait10 has had considerable success with video-assisted thoracoscopy and talc poudrage (94%) in AIDS-related pneumothorax (including in advanced AIDS). He questions the earlier support given by Vricella and Trachiotis to the Heimlich valve7 and suggests its use may simply be shifting "an unresolved pleural space problem from the inpatient to the outpatient setting."10 This criticism of Heimlich valve use seems valid and emphasizes tailoring the management approach to the individual patient circumstances, including severity of underlying AIDS and patient preferences. However, there seems to exist a common reluctance to offer a surgical approach in these patients, likely related to the potential risk to the operative team. Vricella and Trachiotis, and Metersky et al,9 noting the potential for success, incorporate surgical options including video-assisted thoracoscopic approaches in their treatment protocols in "acceptable" operative candidates. Unfortunately, they do not clearly define "acceptable." Surgical studies, including advanced AIDS patients (mean CD4 counts < 100), emphasize early surgical intervention, noting limited operative morbidity and mortality.11 12 13 Perhaps the usual preoperative risk considerations should suffice despite the presence of advanced AIDS, given the potential for success.
The use of Heimlich valve or similar device may afford an earlier patient discharge, but integral to this concept is the ability of physicians to make timely therapeutic decisions. Regardless of the type of spontaneous pneumothorax, prolonged hospital monitoring of an air leak due to physician indecision appears to be a common tendency.14 Given the many potentially successful therapeutic options available for a continued air leak, including Heimlich valve and surgery, the duration of air leak monitoring should be consciously limited and foremost in the physician’s approach. A forthright assessment of the patient’s risks and delineation of the options with the patient should lead to prompt therapeutic selection. Metersky et al9 arbitrarily suggested 5 days of continued air leak as an appropriate decision point; the current authors suggest a decision point at 24 to 48 h. I opt for the shorter time point based on the study by Schoenenberger et al15 of COPD-related pneumothoraces. Peak spontaneous air leak resolution occurs at 48 h in this group of patients with COPD-related pneumothoraces. Regardless of the therapeutic intervention chosen, prolonged hospital air leak monitoring in the setting of an advanced AIDS patient’s pneumothorax is only prolonging hospitalization in an already drastically limited patient life span.
References
This article has been cited by other articles:
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  F. Bellemare, M.-P. Cordeau, J. Couture, E. Lafontaine, P. Leblanc, and L. Passerini Effects of Emphysema and Lung Volume Reduction Surgery on Transdiaphragmatic Pressure and Diaphragm Length* Chest, June 1, 2002; 121(6): 1898 - 1910. [Abstract] [Full Text] [PDF]
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