Modified sleeve anastomosis in large muscular arteries of sheep.

OBJECTIVE: The purpose of this investigation was to test a modified telescopic anastomosis in large muscular arteries. MATERIAL AND METHODS: The right carotid arteries in 30 sheep (average weight 57+/-5.7 kg) were transected and anastomosed end to end using two guided sutures and compared with a control group (10 sheeps) using two external sutures (Lauritzen method). RESULTS: The mean time to complete the anastomosis (4.5 min) and hemostasis (4.3 min) in the experimental group was less than the control group (17.3 min for anastomosis and 6.4 min for hemostasis) (P<0.05). In addition, the total amount of blood loss during the modified anastomosis was significantly lower than Lauritzen method (3.8 versus 8 ml). In both experimental and control groups the scanning electron microscopy (SEM) at 90th day post-operation revealed a continuous smooth layer of endothelial cells covering the anastomotic junction. CONCLUSIONS: Anastomosis with two guided sutures is easy and faster to perform and could be applicable to an acutely transected vessel.

Aortic root dilatation in patients with emphysema.

BACKGROUND: Abdominal aortic aneurysms have been recognized to occur more frequently in patients with emphysema. However, the prevalence of aortic root dilatation in patients with emphysema and its relationship to risk factors for aortic enlargement have not been previously described. METHODS: We studied 47 patients, past smokers (aged 67 +/- 6 years, 18 women) with severe emphysema diagnosed by a pulmonary function test and an ultrafast computed tomographic scan. Two-dimensional echocardiography was used to measure the aortic root at the aortic annulus, sinus of Valsalva, sinotubular junction and proximal part of the ascending aorta. Measured mean values were compared with published normal values and age- and sex-matched patients without emphysema. The relationship between aortic root size and cardiac risk factors (hypertension, hypercholesterolemia, and diabetes) was also examined. RESULTS: In patients with emphysema the mean aortic root dimensions were significantly larger than normal values at each measured site (P <.0001) and those of patients without emphysema (P <.05 to.0001). A substantial percentage of patients with emphysema had larger sinus of Valsalva (43%) and proximal ascending aorta (59%) than the upper limit of normal. In the multivariable regression model, emphysema was a significant determinant of aortic root size at all measured sites and hypertension was associated with additional dilatation at the sinus of Valsalva, sinotubular junction, and proximal ascending aorta. CONCLUSIONS: (1) In patients with emphysema the aortic root dimension is significantly larger than in patients without emphysema. (2) Systemic hypertension is associated with additional enlargement of the proximal ascending aorta, the sinus of Valsalva, and the sinotubular junction.

Use of forced inspiratory vital capacity to identify bronchodilator reversibility in obstructive lung disease.

The objective of this study was to assess the utility of forced inspiratory vital capacity (FIVC) to identify bronchodilator reversibility (BDR) for patients with obstructive lung disease (OLD) in relation to customary BDR criteria as defined by the American Thoracic Society (ATS). Concurrent data analysis was used in an academic medical center setting. Two hundred patients with OLD (including chronic obstructive lung disease and asthma) undergoing testing at the Pulmonary Function Laboratory at Cedars-Sinai Medical Center from January 1995 to December 1996 were identified. These 200 patients were categorized into four grades of obstruction by ATS-defined forced expiratory volume in 1 sec (FEV1) criteria (severe, moderately severe, moderate, and mild). Each of these groups was further subdivided into equal subgroups according to the presence (+) or absence (-) of BDR. Inspiratory flow-volume loops and FIVC were analyzed for each of these subgroups. Of the patients exhibiting BDR on the forced expiratory maneuver (FEM), FIVC correctly identified 53% of the cases. For patients not exhibiting BDR on FEM, FIVC identified an additional 12 cases. In 72% of cases, the maximal FIVC was not obtained from the maximal FEM flow-volume loop. FIVC inspection of the data (which were already available from standard spirometric testing) identified a subgroup of OLD patients with BDR not appreciated by FEV1 or FVC criteria, which may respond to bronchodilator therapy. The maximal FIVC value should be obtained by manual inspection to identify the best inspiratory flow-volume loop.

Motivating factors in futile clinical interventions.

With modern medical technology, it is now possible to sustain life for prolonged periods in critically ill patients, even when there is no reasonable hope of improvement or achieving the goals of therapy. Such futile and medically inappropriate interventions may violate both the ethical and medical precepts generally accepted by patients, families, and physicians. In this study, we sought to determine who was primarily responsible for such interventions, the nature of their motivation, and the role of a timely bioethical consultation. In a retrospective review, we identified 100 patients of 331 bioethical consultations who had futile or medically inappropriate therapy. The average age of patients was 73.5 +/- 32 years (mean +/- 2 SD) with 57% being male. Fifty-seven percent of the patients were admitted to the hospital with a degenerative disorder, 21% with an inflammatory disorder, and 16% with a neoplastic disorder. The family was responsible for futile treatment in 62% of cases, the physician in 37% of cases, and a conservator in one case. Unreasonable expectation for improvement was the most common underlying factor. Family dissent was involved in 7 of 62 cases motivated by family, but never when physicians were primarily responsible. Liability issues motivated physicians in 12 of 37 cases where they were responsible but in only 1 of 62 cases when the family was (chi(2) 5 degrees of freedom = 26.7, p < 0.001). When the bioethics consultation resulted in cessation of the therapy, patients died in a median of 2 days as opposed to 16 days if therapy continued (p < 0.001).

Measurement of gastric P(CO2) as an index of tissue hypoxia during obstructive sleep apnea.

BACKGROUND: Gastric mucosal ischemia develops in critically ill patients in a number of clinical settings due to diversion of blood flow from the splanchnic bed to more vital organs, and can be detected by the measurement of gastric intramucosal pH (pHi). STUDY OBJECTIVE: We hypothesized that similar changes would occur during obstructive sleep apnea (OSA) due to increased respiratory work during the periods of apnea. METHODS: Gastric P(CO2), pHi and arterial blood gases were measured during 3 conditions in 8 patients with severe OSA: at baseline awake, while asleep with > or = 30 obstructive apneas or hypopneas per hour, and asleep after elimination of apneas with continuous positive airway pressure (CPAP). RESULTS: Significant changes between the baseline and apnea conditions were detected using ANOVA for repeated measures for gastric P(CO2), 40.2 +/- 5.3 vs. 85.4 +/- 34.0 (p < 0.001), pHi, 7.41 +/- 0.06 vs. 7.11 +/- 0.17 (p < 0.005), and the gastric-arterial P(CO2) difference (D(CO2)), -2.3 +/- 5.5 vs. 44.3 +/- 36.21 (p < 0.006). Nasal CPAP returned all measures back to baseline values. CONCLUSIONS: Gastric tissue hypoxia develops in patients with severe OSA and may be a marker of disease severity. Treatment of OSA with CPAP eliminates the regional tissue hypoxia.

The value of a hospitalist service: efficient care for the aging population?

BACKGROUND: We studied patients of a hospitalist teaching service and patients receiving routine private care (control subjects). We sought to evaluate whether inpatients cared for by an academic hospitalist service had lower lengths of stay and resource utilization rates. METHODS: Using monthly hospital census data, 477 hospitalist cases and 1,160 control cases were selected by explicit criteria from the Medicaid population of a large, university-affiliated, community medical center between July 1, 1996, and June 30, 1997. Outcomes in hospitalist faculty patients were compared to those of control patients under the care of private providers. RESULTS: Median length of stay was 4 days for control subjects and 3 days for the hospitalist service (p < 0.0001). Median total cost per case was $4,853 for control subjects and $4,002 for hospitalist patients (p < 0.0001). Only patients > or = 65 years old showed statistically significant reductions in both length of stay (p < 0.0001) and total cost (p = 0.002). Subspecialty consultation rates were 37.6% for control subjects and 16.6% for hospitalist cases (p < 0.0001). We noted increasing consultations for patients > or = 65 years old, especially in the control group (p = 0.001). No significant differences in mortality, 30-day readmissions, or interfacility transfers were observed. CONCLUSIONS: Patients cared for by an academic hospitalist service that includes actively participating medical residents appear to have lower lengths of stay, total costs, and consultation rates than patients receiving routine private care. The reductions are largely observed among patients > or = 65 years old.

Pulmonary physiologic changes of morbid obesity.

OBJECTIVE: Our objective was to study the effects of extreme obesity on pulmonary function tests and the effects of smoking on these variables in a population group larger than has previously been reported. DESIGN: Retrospective data analysis. SETTING: Academic medical center. PATIENTS: Forty-three patients with extreme obesity [ratio of weight in kilograms to height in centimeters greater than 0.9 (W/H)] who underwent pulmonary function testing at Cedars-Sinai on an out-patient or in-patient basis during the period of 1979 to 1 997. MEASUREMENTS AND RESULTS: Patients underwent standard pulmonary function testing. The patients were divided into 2 groups based on the W/H ratio: group A (0.9-0.99) and group B (greater than 1.0). Chart review was performed to identify pertinent history/co-morbidities. The independent effects of smoking between each group's patients were assessed. Forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), expiratory reserve volume (ERV), functional residual capacity (FRC), maximum voluntary ventilation (MVV), and forced expiratory flow during midexpiratory phase (FEF25-75%,) were significantly reduced in both groups. Single-breath diffusing capacity for carbon monoxide (DLCO) and the volume of gas into which the single-breath of carbon monoxide and helium was diluted were not elevated. Smoking did not account for the results in group A but did seem to partially explain the decrease in FVC, FEV1, and FEF25-75% in group B. CONCLUSIONS: Extreme obesity is associated with a reduction in ERV, FVC, FEV1, FRC, FEF25-75%, and MVV. However, contrary to prior reports, D(LCO) is not elevated. These effects are only partially explained by smoking.

Guidelines in pulmonary medicine: a 25-year profile.

OBJECTIVE: We attempted to identify clinical practice guideline and pathway articles in the area of pulmonary medicine published in peer-reviewed journals since 1974. DESIGN: Review. DATA SOURCES: MEDLINE, the Cochrane Database, Best Evidence, and Abstracts of Clinical Care Guidelines from January 1974 to December 1998. STUDY SELECTION: All articles contained relevant search terms for pulmonary topics and were included irrespective of setting (primary or specialty, inpatient or outpatient). Controlled and uncontrolled trials as well as observational studies and consensus opinion/statements were all identified. The articles were stratified by design as well as by pulmonary topic. DATA EXTRACTION: Limited data on study type, study focus, year of publication, and results of study were abstracted. RESULTS: Our criteria yielded 271 articles, including 115 consensus statements and expert opinion guidelines; 30 controlled studies, meta-analyses, or systematic reviews; and 126 uncontrolled trials and observational studies. Of these, 82 articles (30.3%) related to asthma, 46 articles (17.0%) related to COPD, and 36 articles (13.3%) related to pneumonia. In addition, we tracked the increasing publication of all guideline-related pulmonary articles; randomized, controlled trials (RCTs); systematic reviews; and consensus statements by year for the past 25 years. CONCLUSION: Pulmonary guidelines are increasingly published in peer-reviewed journals, but few are tested clinically in RCTs. There is continued reliance on consensus statements and expert opinion. Pulmonary guideline publications have continued to dramatically increase in number and in importance since 1974, both on the local level and internationally.

Downward trends in bronchoscopies performed between 1991 and 1997.

STUDY OBJECTIVE: To examine the frequency of bronchoscopy performance in a large tertiary medical center over a period of 8 years. DESIGN: Retrospective data analysis. SETTING: Academic medical center. MATERIALS AND METHODS: Using a computerized database of all bronchoscopies performed between 1991 and 1997, we analyzed trends in (1) the total number of bronchoscopies; and (2) the numbers of bronchoscopies performed for patients on the basis of the postbronchoscopic diagnosis in the following three main disease groups: AIDS, interstitial lung disease (ILD), and lung cancer. We measured the following outcomes in the patients of high-volume and low-volume bronchoscopists: procedure length (time to perform procedure), nondiagnostic rate, and repeat-bronchoscopy rate. In addition, we compared total admissions, outpatient visits, and insurance status of the patients during the same period. RESULTS: In total, 5,580 bronchoscopies were performed. A 17% decline in the number of procedures was noted between 1991 and 1997 (from 943 to 783, respectively; p < 0.05). The number of AIDS-related bronchoscopies fell from 235 (25% of 943) to 96 (12% of 783), a 59% decline during this period (p < 0.05). There was a corresponding 76% decrease in the number of bronchoscopies associated with a diagnosis of Pneumocystis carinii pneumonia (PCP; p < 0.05). During the same period, no similar decrease was noted in the number of bronchoscopies associated with a diagnosis of ILD or lung cancer. Moreover, no significant differences were noted in the procedure length, nondiagnostic rate, or repeat-bronchoscopy rate between high-volume and low-volume bronchoscopists. Although there was no significant change in the number of total admissions between 1991 and 1997, there was a 48% increase in the number of managed-care patients and a 25.4% increase in the number of Medicaid health insurance program for California patients between 1991 and 1997. CONCLUSIONS: We noted a significant decline in the number of bronchoscopies performed between 1991 and 1997. The significant reduction in the number of AIDS-associated bronchoscopies accounted for 87% of the decline. Other possible factors include the introduction of a management pathway for the empiric treatment of PCP in 1996, a reduction in the number of pulmonary admissions, an increase in the number of managed care patients, and a reduction in the remuneration for the performance of bronchoscopy.

Impact of clinical pathways and practice guidelines on the management of acute exacerbations of bronchial asthma.

OBJECTIVES: In 1990, it was estimated that approximately 1% of all US health-care costs (approximately $6.2 billion) were spent on asthma-related health expenses. Of this, hospitalization charges alone exceeded $2.6 billion. Practice guidelines and clinical pathways are being developed to standardize the management of acute asthma with the aim of improving care and safely reducing health-care costs. In this report, we evaluate the impact of an asthma pathway developed and instituted at a large community-based teaching hospital. This pathway was evidence based and was developed by a multidisciplinary group. METHODS: The study was conducted during a 6-month period in 1995, while a similar period in 1994 was used as a historical control period. Data collected included patient demographics, hospital admission and discharge peak expiratory flow rates, pulse oximetry measurements, length of stay, conversion from hand-held nebulizer to metered-dose inhaler, use of corticosteroids within 24 h of hospitalization, and conversion of i.v. steroids to oral steroids. RESULTS: A total of 42 patients were enrolled during the study period. Of these, 19 were placed on the pathway, while 23 were not treated according to the pathway. There were 38 patients in the 1994 historical control period. For 1995, there was no significant difference between the pathway and nonpathway groups with regard to the length of stay (4.4+/-3.3 vs 3.2+/-2.3 days; p > 0.05), hospital discharge peak expiratory flow rates (324 vs 286 L/min; p > 0.05), or use of steroids (100% vs 91%; p > 0.05). However, a significant increase in conversion from hand-held nebulizer to metered-dose inhaler was noted in the pathway group (68% vs 34%; p < 0.05). The data from 1994 compared to 1995 pathway were similar in that there was no difference in the length of stay (3.4+/-2.1 vs 4.4+/-3.3 days; p > 0.05) and/or use of steroids (92% vs 100%; p > 0.05), while a significant increase in hand-held nebulizer to metered-dose inhaler conversion was observed for the 1995 pathway group (68% vs 26%; p=0.002). CONCLUSIONS: We conclude that although the asthma pathway did not significantly reduce length of stay, it was associated with a significant increase in hand-held nebulizer to metered-dose inhaler conversion, resulting in a substantial cost savings of $288,000/year.

Methodologic problems encountered with cooximetry in methemoglobinemia.

The objectives of this study were to examine the reported accuracy of cooximetry in determination of methemoglobin levels, to report the apparent discrepant values of "measured" methemoglobin and carboxyhemoglobin, and to discuss the effect that methemoglobinemia has on pulse oximetry readings. Secondly, relative oxygen saturations measured by pulse oximetry and calculated from arterial blood gas samples were compared. A retrospective analysis was performed in an academic medical center with two patients who were diagnosed with acute methemoglobinemia after taking sulfa-containing medications. Serial pulse oximetry, arterial blood gas, and cooximeter analysis were performed for two patients. Cooximetry was performed using an IL-482 oximeter, arterial blood gas analysis was performed using a BLE 1400 oximeter, and pulse oximetry was performed using Ohmeda Biox S740, Hewlett Packard SPO2, or Marquette SPO2 models. Methemoglobin levels ranged from 6% to 48%, however, summation of methemoglobin and oxyhemoglobin were as high as 120%. As a result, negative values of carboxyhemoglobin were recorded by the cooximeter, generating a total sum of 100%. Comparison of pulse oximetry and arterial blood gas oxygen saturation (measured and calculated values, respectively) revealed significant discrepancies; methemoglobin was > 9%, whereas oxygen saturation uniformly was lower with pulse oximetry. Therefore, we recommend that when methemoglobin levels exceed 10%, cooximetry be used as a screen for methemoglobinemia and that serial cooximeter measurements be used to guide therapy and reliance on noninvasive pulse oximetry.

Assessment of postural differences in regional pulmonary perfusion in man by single-photon emission computerized tomography.

1. With the advent of single-photon emission computerized tomography, controversy has arisen with regard to the significance of gravitational influences on regional pulmonary perfusion (Qr) in the supine versus prone postures. We investigated the dorsal-ventral distributions of Qr in prone (n = 5) and supine (n = 5) normal subjects, as assessed by single-photon emission computerized tomography after intravenous injection of technetium-99m-labelled macroaggregated albumin at end-tidal expiration. Reconstructed serial (one pixel thickness) coronal sections were traced on a computer screen, to yield the encompassed radioactive counts and number of pixels per each image. Coronal section data (expressed as mean radioactive counts/pixel) were expressed in a 'profile' and normalized to the maximum coronal section of each lung (% maximum). 2. Coefficients of variation and linear regression slopes for the prone versus supine profiles for left and right lungs were not statistically different (unpaired Student's t-test). The coronal section with maximum Qr was identified in the more dependent lung regions and, hence, affected by gravity. 3. We conclude that, in contrast to previous canine models, which have suggested postural differences in dorsal-ventral perfusion gradients, in normal man gravity primarily determines the non-dependent to dependent distribution of Qr. We speculate that interspecies differences in physiology may be teleological and related to the different perfusion demands of the quadruped compared with upright man.

Upper airway obstruction secondary to acinic cell carcinoma of the trachea. Use of Nd:YAG laser.

Comprising 1 to 4% of all tumors and 7 to 15% of malignant neoplasms of the major salivary glands, acinic cell carcinoma (ACC) rarely occurs in the respiratory tract. There has been only one case of ACC of the trachea previously reported in the medical literature. A second case of ACC of the trachea associated with upper airway obstruction and its management by Nd: YAG laser and surgical resection is reported.

Clinical strategies to reduce utilization of chest physiotherapy without compromising patient care.

BACKGROUND: There is widespread interest in the evaluation of clinical strategies that safely reduce health-care costs. Elimination of inappropriate chest physiotherapy may represent one of those strategies. SETTING: An academic community hospital. METHODS: One-hundred one patients receiving chest physiotherapy were prospectively randomized to continue their chest physiotherapy or to inform their physicians that the order for the chest physiotherapy may have been inappropriate. RESULTS: Patients who were randomized to have their chest physiotherapy discontinued received 45% fewer chest physiotherapy treatments than control patients (p < 0.01). There was no increase in the mortality rate or length of hospital stay associated with the reduction in chest physiotherapy in carefully selected patients. The estimated cost savings would be $319,000, which is 50 times greater than the cost associated with the intervention. CONCLUSION: Chest physiotherapy is frequently provided to patients for inappropriate indications. Reducing chest physiotherapy for these patients may significantly reduce respiratory therapy costs without increasing length of stay or mortality rates.

Gastric intramural pH in mechanically ventilated patients.

BACKGROUND: The hypothesis that gastric intramural pH (pHi) is predictive of outcome in haemodynamically stable, mechanically ventilated patients was tested in 25 patients on assisted mechanical ventilation for respiratory failure. METHODS: Simultaneous samples of arterial blood and gastric juice were obtained from patients on assist control, synchronised intermittent and pressure control ventilation during the first 48 hours of mechanical ventilation. Gastric pHi was calculated from the equation: pHi= 6.1 + log HCO3/(gastric PCO2 X 0.03). The outcome was survival or death due to respiratory or circulatory failure within 45 days of admission. RESULTS: Gastric pHi proved to be a better predictor of outcome than all presently utilised parameters. Although all patients included in this study were haemodynamically stable and were similar for all laboratory indices, the only variable capable of accurately predicting outcome was gastric pHi. Patients with a normal arterial pH but a gastric intramural pH of less than 7.25 had an observed mortality of 66%. Standard severity of illness scores grossly underestimated mortality rates. The sensitivity and specificity of a gastric pHi value of less than 7.25 in predicting death were 86% and 83%, respectively. A receiver operator curve for all variables exaggerates the superiority of gastric pHi as a predictor of outcome. CONCLUSION: Low gastric pHi, a marker of gastrointestinal ischaemia, may occur in the presence of normal haemodynamics and may be used to predict severity of illness and mortality accurately.

Isolated reduction in single-breath diffusion capacity in young, healthy, asymptomatic women.

The clinical significance of an isolated reduction in the carbon monoxide diffusing capacity (DLCO) in nonsmoking, asymptomatic individuals is not known. Whether a reduced DLCO despite otherwise normal pulmonary function tests warrants further investigation remains unanswered. In this article, the authors describe five healthy, asymptomatic, young women who had isolated, reduced DLCO and subsequent follow-up examinations over a span of 6 years. This case series lends support to the contention that an isolated low DLCO in asymptomatic subjects is not clinically significant and does not necessitate additional medical inquiry.

Isogravitational heterogeneity of perfusion after unilateral lung transplantation.

1. Single-photon emission computerized tomography in both an intact canine model and man has demonstrated an aspect of pulmonary perfusion to be independent of gravitational forces. 2. Using technetium 99m-labelled macroaggregated albumin single-photon emission computerized tomographic imaging, we investigated normal human subjects (n = 5), stable unilateral lung transplant recipients (n = 6) and transplant recipients with chronic allograft dysfunction related to obliterative bronchiolitis (n = 5). 3. In coronal isogravitational sections, a 1 x 1 x N pixel strip (medial to lateral) was constructed through the 'core' pixel of maximal radioactive counts. The counts were measured for the 'core' pixel and at two mid-points (medial and lateral) between the core pixel and the lung edges. Coefficients of variation were computed for each isogravitational strip and compared between groups. Fractional whole-lung perfusion was determined for left versus right lungs of normal subjects and allograft versus native lungs of transplant recipients. 4. Using these indices, 'isogravitational heterogeneity' (i.e. increased 'core' versus peripheral perfusion) was observed in allografts and native diseased lungs after unilateral transplantation. Despite significantly increased fractional whole-lung perfusion directed to the allografts (84.8% +/- 3.0% and 75.8% + 12.1% for stable unilateral lung transplant recipients and patients with obliterative bronchiolitis respectively) compared with normal lungs (50.2% +/- 1.2% and 49.8% +/- 1.2% for left and right respectively), 'isogravitational flow heterogeneity' (i.e. increased 'core' versus peripheral perfusion) was preserved after transplantation. 5. These findings suggest that 'isogravitational heterogeneity' was maintained despite increased unilateral pulmonary perfusion and the presumed increase in pulmonary capillary recruitment and/or distension.

Spinal aspergillus abscess in a patient with bronchocentric granulomatosis.

Aspergillus fumigatus hyphae is often found in the lung tissue of patients with bronchocentric granulomatosis (BCG). This organism is believed to be one agent responsible for inciting the hypersensitivity response and subsequent development of the characteristic pathology that defines BCG. The definitive etiology of this disease, however, remains conjectural. Corticosteroids represent the mainstay of therapy. The fungi recovered from patients with BCG are considered noninvasive; thus, the risk of fungal invasion secondary to steroid-induced immunosuppression is believed to be negligible. However, we report a case of spinal aspergillus abscess that developed in a patient with BCG subsequent to steroid therapy. This case also highlights the necessity for aggressive medical and neurosurgical intervention to avert the development of neurological sequelae.

Persistence of Pneumocystis carinii in patients with AIDS receiving chemoprophylaxis.

Pneumocystis carinii organisms have been shown to persist throughout therapy in the majority of patients with Pneumocystis carinii pneumonia (PCP). This study evaluated the relationship between persistence of organisms and recurrence of disease, and the effect of chemoprophylaxis on bronchoalveolar lavage specimens. Seven patients receiving PCP chemoprophylaxis underwent serial bronchoalveolar lavage (BAL) examinations at 1, 4, and 7 mo after recovery from a first episode of PCP. Specimens were examined for persistent organisms with Gomori's methenamine silver stain and immunofluorescent antibody staining. There were no persistent organisms 1 mo after completion of antimicrobial treatment in six of the seven patients. The one patient with persistent organisms demonstrated clearance of organisms by 4 mo and had no recurrence of PCP. One patient had a recurrence of PCP at 4 mo, after a negative 1-mo BAL. We conclude that a positive BAL result by silver stain or immunofluorescent antibody staining more than a month after ending treatment may indicate clinical recurrence of PCP and not just persistence of nonpathologic cysts. These findings suggest that recurrences of PCP are more likely due to new infection than to relapse of prior disease.