Functional Recovery After Lung Resection: A Before and After Prospective Cohort Study of Activity.

BACKGROUND: Postoperative recovery is an important measure in thoracic operations. Personal activity monitors can be used to track progress in the preoperative and postoperative settings. This study investigates associations of preoperative activity, lung resection extent, and operative approach with inpatient and outpatient functional recovery as measured by activity monitors. METHODS: In this prospective observational cohort study, patients undergoing lung resection at a single institution wore activity monitors 30 days before through 30 days after operation (between July 2015 and May 2017). Activity was recorded as steps per day, and each patient served as his or her own baseline. Patients were clustered into three activity level groups. Associations among preoperative and postoperative activity, length of stay (LOS), and operative approach were assessed by using generalized regression models with adjustment for patient demographic and clinical characteristics and operative details. RESULTS: Sixty-six patients comprised the study cohort and were grouped by average preoperative activity: low, 21 patients (31.8%); moderate, 27 patients (40.9%); and high, 18 patients (27.3%). The mean age was 66.1 ± 11.6 years; 32 patients (48.5%) were women. Sex, comorbidity, resection extent, and operative approach did not differ among groups. After adjustment for age, comorbidities, resection extent, operative approach, and complications, higher levels of preoperative activity were independently associated with higher postoperative activity in both inpatient and outpatient settings (ß = 1.11, 95% confidence interval [CI]: 1.00 to 1.22, p = 0.04; ß = 1.18, 95% CI: 1.07 to 1.30, p = 0.001) but not LOS. CONCLUSIONS: LOS is not associated with measures of preoperative or postoperative physical activity after adjustment for several factors. However, the association between preoperative activity and postoperative activity, irrespective of age, operative approach, resection extent, and other factors, offers a potential framework for designing recovery trajectory pathways and intervention development in both postoperative inpatient and outpatient settings.

Comparison of real-time PCR and microscopy for malaria parasite detection in Malawian pregnant women.

BACKGROUND: New diagnostic tools for malaria are required owing to the changing epidemiology of malaria, particularly among pregnant women in sub-Saharan Africa. Real-time PCR assays targeting Plasmodium falciparum lactate dehydrogenase (pfldh) gene may facilitate the identification of a high proportion of pregnant women with a P. falciparum parasitaemia below the threshold of microscopy. These molecular methods will enable further studies on the effects of these submicroscopic infections on maternal health and birth outcomes. METHODS: The pfldh real-time PCR assay and conventional microscopy were compared for the detection of P. falciparum from dried blood spots and blood smears collected from the peripheral blood of 475 Malawian women at delivery. A cycle threshold (Ct) of the real-time PCR was determined optimizing the sensitivity and specificity of the pfldh PCR assay compared to microscopy. A real-time PCR species-specific assay was applied to identify the contribution to malaria infections of three Plasmodium species (P. falciparum P. ovale and P. malariae) in 44 discordant smear and pfldh PCR assay results. RESULTS: Of the 475 women, P. falciparum was detected in 11 (2.3%) by microscopy and in 51 (10.7%) by real-time PCR; compared to microscopy, the sensitivity of real-time PCR was 90.9% and the specificity 91.2%. If a Ct value of 38 was used as a cut-off, specificity improved to 94.6% with no change in sensitivity. The real-time PCR species-specific assay detected P. falciparum alone in all but four samples: two samples were mixed infections with P. falciparum and P. malariae, one was a pure P. malariae infection and one was a pfldh PCR assay-positive/species-specific assay-negative sample. Of three P. malariae infections detected by microscopy, only one was confirmed by the species-specific assay. CONCLUSIONS: Although microscopy remains the most appropriate method for clinical malaria diagnosis in field settings, molecular diagnostics such as real-time PCR offer a more reliable means to detect malaria parasites, particularly at low levels. Determination of the possible contribution of these submicroscopic infections to poor birth outcomes and maternal health is critical. For future studies to investigate these effects, this pfldh real-time PCR assay offers a reliable detection method.

High-throughput pooling and real-time PCR-based strategy for malaria detection.

Molecular assays can provide critical information for malaria diagnosis, speciation, and drug resistance, but their cost and resource requirements limit their application to clinical malaria studies. This study describes the application of a resource-conserving testing algorithm employing sample pooling for real-time PCR assays for malaria in a cohort of 182 pregnant women in Kinshasa. A total of 1,268 peripheral blood samples were collected during the study. Using a real-time PCR assay that detects all Plasmodium species, microscopy-positive samples were amplified individually; the microscopy-negative samples were amplified after pooling the genomic DNA (gDNA) of four samples prior to testing. Of 176 microscopy-positive samples, 74 were positive by the real-time PCR assay; the 1,092 microscopy-negative samples were initially amplified in 293 pools, and subsequently, 35 samples were real-time PCR positive (3%). With the real-time PCR result as the referent standard, microscopy was 67.9% sensitive (95% confidence interval [CI], 58.3% to 76.5%) and 91.2% specific (95% CI, 89.4% to 92.8%) for malaria. In total, we detected 109 parasitemias by real-time PCR and, by pooling samples, obviated over 50% of reactions and halved the cost of testing. Our study highlights both substantial discordance between malaria diagnostics and the utility and parsimony of employing a sample pooling strategy for molecular diagnostics in clinical and epidemiologic malaria studies.