Inaccuracy of estimating peak work rate from six-minute walk distance in patients with COPD.

INTRODUCTION: The cardiopulmonary exercise test (CPET) and the 6-minute walk test (6MWT) are used to prescribe the appropriate training load for cycling and walking exercise in patients with chronic obstructive pulmonary disease (COPD). The primary aims were: (i) to compare estimated peak work rate (Wpeak(estimated)) derived from six existing Wpeak regression equations with actual peak work rate (Wpeak(actual)); and (ii) to derive a new Wpeak regression equation using six-minute walk distance (6MWD) and conventional outcome measures in COPD patients. METHODS: In 2906 patients with COPD, existing Wpeak regression equations were used to estimate Wpeak using 6MWD and a new equation was derived after a stepwise multiple regression analysis. RESULTS: The 6 existing Wpeak regression equations were inaccurate to predict Wpeak(actual) in 82% of the COPD patients. The new Wpeak regression equation differed less between Wpeak(estimated) and Wpeak(actual) compared to existing models. Still, in 74% of COPD patients Wpeak(estimated) and Wpeak(actual) differed more than (±) 5 watts. CONCLUSION: In conclusion, estimating peak work load from 6MWD in COPD is inaccurate. We recommend assessment of Wpeak using CPET during pre-rehabilitation assessment in addition to 6MWT.

Inappropriate prescription of proton pump inhibitors on two pulmonary medicine wards.

OBJECTIVE: We recently noticed that proton pump inhibitor (PPI) use was high on a pulmonary medicine ward of a university clinic and reasons for this high usage were not clear. Our aim was to determine the indications for PPI use on two pulmonary medicine wards and to assess whether this use was appropriate. METHODS: We assessed prospectively the number of patients on PPIs and the indications for PPI use on two pulmonary medicine wards, one from a university and one from a regional clinic in The Netherlands. RESULTS: On admission, 88 of 300 (29%) patients already used PPIs. The use of PPIs was discontinued in three (1%) patients, whereas PPIs were initiated in 45 (15%) patients, resulting in 130 (43%) patients on PPIs during hospitalization. The most common indication for PPI use was the prevention of medication-associated complications. In 78 of 130 (60%) patients on PPIs, this medication was used for a registered indication, whereas in 52 (40%) patients a registered indication was not present (overuse). In contrast, 19 of 300 (6%) patients were not prescribed PPIs despite the presence of a registered indication for its use (underuse). No differences were found in prescription rate and indications for PPI use between the university and the regional clinic. CONCLUSION: PPI use was very common on two pulmonary medicine wards in the Netherlands. Forty percent of the patients used their PPIs for a nonregistered indication. As use of PPIs is costly and may be associated with side effects, hospital physicians should to be better educated on guidelines for its use.

Automated analysis of pleural fluid total and differential leukocyte counts with the Sysmex XE-2100.

BACKGROUND: Determination of leukocyte (WBC) counts in pleural fluid is routinely performed by microscopic examination. In this study, we evaluated the performance of automated (differential) WBC counting in comparison with manual counting. METHODS: Pleural fluid samples (n=45) were obtained from patients undergoing diagnostic thoracocentesis. The manual total WBC count was determined after Samson staining in a Fuchs-Rosenthal hemocytometer; microscopic differential counts were performed on May-Grünwald Giemsa-stained cytospin slides. The Sysmex XE-2100 hematology analyzer was used for automated (differential) WBC counting. The functional detection limit was determined by serial dilution of continuous ambulatory peritoneal dialysis (CAPD) fluid and replicate measurements of each dilution. RESULTS: The automated WBC count (x10(6)/L) was highly correlated with that of the microscopic reference method (r(2)=0.95; WBC-analyzer=0.97 x WBC-reference method+16; n=45). Good agreement was also observed for the absolute lymphocyte count (r(2)=0.92; WBC-analyzer=0.99 x WBC-reference method+32; n=36), neutrophil count (r(2)=0.94; WBC-analyzer=0.91 x WBC-reference method+6; n=35), and monocyte count (r(2)=0.73; WBC-analyzer=0.83 x WBC-reference method+6; n=38). The functional detection limit for WBCs was calculated at 50 x 10(6)/L (coefficient of variation 20%). CONCLUSIONS: With some limitations, total and differential WBC counts in pleural fluid can be reliably determined using the Sysmex XE-2100 instrument.