In the years preceding the general epidemic of HIV.

In the years preceding the general epidemic of HIV, Pneumocystis carinii was a relatively rare clinical pathogen. Pneumocystis carinii pneumonia (PCP) was, as it is now, an opportunistic infection which occurr in immunosuppressed patients. At that time, it was commonly accepted that PCP required an invasive step usually open lung biopsy, for definitive diagnosis.[1] This was in part based onward the knowledge that, in patients dying of this infection, organisms appeared to be limited to the alveolar space and did not increase appreciably out of this compartment. Further, noninvasive conducts in sporadic cases failed to yield a diagnosis. Although not evaluated in a large series, sputum examination was consistently reported to be of no diagnostic value.

The HIV epidemic necessitated a re-evaluation of Pneumocystis diagnosis. Clinicians discovered at the start of the epidemic that lay open lung biopsy was unnecessary for the diagnosis of PCP in the HIV-positive patient.[2] Bronchoscopy with bronchoalveolar lavage and transbronchial biopsy were as effective and associated with les morbidity. succeeding studies have established, in change the direction of that bronchoscopy with bronchoalveolar lavage alone is virtually as sensitive as bronchoscopy with the pair lavage and transbronchial biopsy.[3] Thus, we now understand that PCP cases can be discovered with bronchoalveolar lavage performed at bronchoscopy

The at any time increasing population of HIV-positive patients and the frequent occurrence of PCP in this population have quicked a search for even les invasive diagnostic processs which may also be more charge effective. Sputum induction and nonbronchoscopic lavage are brace such methods. Sputum induction was initially demonstrated to be a sensitive deed that obviated the need for bronchoscopy in a large number of patients.[4,5] However, near centers had difficulty reproducing these initial promising results[6] What has become clear from these studies is that the interest and the experience of the examiner play a large part as do the sputum-induction protocol and the staining mode for Pneumocystis, in the sensitivity of this technique. In large center that have experience with sputum induction, many invasive deeds can be avoided, with substantial preciousness and comfort benefit to the patient. This may not be the case for smaller center with les experience, suggesting that there is still a ne for alternative strategies for the diagnosis of PCP Catheter lavage was first evaluated in intubated and ventilated patients and was place to be sensitive and safe.[7] However, this orderly disposition of diagnosis has the disadvantage that it is alone applicable to a subset of patients, namely those who are intubated.

In this issue of Chest (see page 816) Bustamante and collect report a study in which they have attempted to reach forth the utility of catheter lavage to nonintubated patients. They make use ofed a coude catheter for nonbronchoscopic bronchoalveolar lavage. They have compared their follows with the coude catheter to accrues with sputum induction in the same patients. Coude catheter lavage, in their hands, is a safe proceeding in which the catheter can be placed through a nonspecialist or even a nonphysician and yields a beneficial sample of lower respiratory tract lining fluid to analyze for Pneumocystis. They establish sputum induction to be a to a high degree insensitive test for PCP (les than 10 percent) This is in contrast to mostly reports which suggest that in 50 percent of patients or better, PCP can be discovered by sputum induction.[4,5] The authors attribute the grave sensitivity of sputum induction in their application of mind to the low frequency of Pneumocystis in their population. However, the number of a nonproductive or an inadequate sputum induction was highly high, and most patients with sputum-negative/lavage-positive samples were in this assemblage Thus, a more vigorous attempt at sputum induction might have yielded a higher sensitivity for this rule of diagnosis. Another difficulty with assessing this report was the lack of a denominator in the contemplation There was no "gold standard," like as bronchoscopy, that catheter bronchoalveolar lavage was compared to, although the authors do imply that no cases were missed on this technique.

A major issue with catheter lavage is safety. The authors report a single incident of gastric intubation with emesis and aspiration early in the disclosure of their technique. The course of this patient was relatively uncomplicated, unless the incident does raise a cautionary flag. The remarkable safety of bronchoscopy is, in part, a function of direct visualization of the field of interest. Intuitively, individual could thus argue that a blind catheter lavage would be more likely to be associated with complications.

More than a decade of experience with PCP in HIV-positive patients has revealed that noninvasive or minimally invasive practices are diagnostic for many patients. Transbronchial biopsy is singularly needed, and open lung biopsy is unnecessary. In center with a particular interest and the expertise afforded by dint of large numbers of patients, sputum induction can decrease the need for more invasive conducts by 75 percent. In settings where les expertise with induced sputum is available, bronchoscopically directed bronchoalveolar lavage is popularly the procedure of choice. Bustamante and call together provide us with new information that the coude catheter lavage may be a safe alternative that is les high-priced and perhaps, more comfortable for the patient. However, many questions remain. in what manner safe is this procedure when performed onward a larger scale or exclusively according to nonphysician operators? How does the sensitivity of this process compare to bronchoscopic bronchoalveolar lavage? Should coude catheter lavage be performed in large center in those patients who are not diagnosed by the agency of sputum induction? The ultimate clinical part of coude catheter lavage in the evaluation of possible PCP in HIV-positive patients will hang on the answers to questions similar as these.

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