PLASMA B-TYPE NATRIURETIC PEPTIDE AS A PREDICTOR OF WEANING OUTCOME OF MECHANICALLY VENTILATED PATIENTS
Manas Kanti Mazumder*, Rocky Das Gupta, Nurjahan Begum, Sheikh UL Alam, Mirza Nahiduzzaman, Nafiza Afroz, Suman Kundu and Shahadat Hossain Polash
Background: There are different criterias and tools act as predictors of weaning outcome of the patients under mechanical ventilation. But each of them has variable predictability. About 20% to 30% of patients who meet the certain criterias for weaning initially, ultimately fail to wean from mechanical ventilation. Cardiovascular dysfunction could be a major underlying mechanism of weaning failure. Recent data suggest that plasma B-type natriuretic peptide, a marker for cardiovascular dysfunction, may predict the outcome of weaning from mechanical ventilation. Objective: The purpose of the study was to evaluate the role of plasma B-type natriuretic peptide as a predictor of weaning among the patients under mechanical ventilation in ICU. Methodology: This study was a prospective cohort study. This study was conducted in the Department of Anesthesia, Analgesia and Intensive Care Medicine at Bangabandhu Sheikh Mujib Medical University, Dhaka, Bangladesh over a period of 2 years. Study population was selected for weaning from mechanical ventilation support for the first time in the age group of more than 18 years with both sexes. Patients with pre-existing diseases that elevate the plasma BNP level were excluded from the study. Weaning criteria was selected by ICU consultant following the standard ICU protocol for every patients enrolled in this study. Patients were subdivided into weaning success and weaning failure groups according to the outcome of weaning process. Plasma BNP level of all patients was measured before and after 2 hours of spontaneous breathing trial. Each blood sample (3ml) was collected by ICU lab technician into a vacutainer with EDTA for anticoagulation. Blood samples were sent to the biochemistry lab and analysis was done by chemiluminescent microparticle immunoassay (CMIA). Serial arterial blood gases done within ICU lab before and after 2hours of SBT and 12hourly up to 48 hours. Patients who were extubated would be followed up for 48 hours after SBT. Result: A total number of 30 patients were recruited for this study. One-third (33.3%) of the patients failed on SBT. The mean age of weaning success and failure groups were 54.90±9.787 years and 57.60±10.091 years respectively. The mean percent changes of BNP (pg/ml) during 2-h of SBT in weaning success and failure groups were 38.41±9.379 and 59.51±2.940 respectively, the difference was statistically significant (p=0.01). The receiver-operating characteristic curve (R0C) analysis for BNP as a predictor of weaning outcome, showed that the area under the curve (AUC) was 0.89. It was found that change of BNP level < 42.5% from baseline had the best combination of sensitivity (90%) and specificity (80%) in predicting weaning outcome. Conclusion: Plasma BNP level can be used as a predictor of weaning outcome among the patients under mechanical ventilation.
Keywords: Plasma BNP, Anesthesia, Analgesia, Intensive Care.
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