Evaluating diaphragmatic dysfunction and predicting non-invasive ventilation failure in acute exacerbation of chronic obstructive pulmonary disease in India.

BACKGROUND: Baseline diaphragmatic dysfunction (DD) at the initiation of non-invasive ventilation (NIV) correlates positively with subsequent intubation. We investigated the utility of DD detected 2 hours after NIV initiation in estimating NIV failure in acute exacerbation of chronic obstructive pulmonary disease (AECOPD) patients. METHODS: In a prospective-cohort design, we enrolled 60 consecutive patients with AECOPD initiated on NIV at intensive care unit admission, and NIV failure events were noted. The DD was assessed at baseline (T1 timepoint) and 2 hours after initiating NIV (T2 timepoint). We defined DD as ultrasound-assessed change in diaphragmatic thickness (ΔTDI) <20% (predefined criteria [PC]) or its cut-off that predicts NIV failure (calculated criteria [CC]) at both timepoints. A predictive-regression analysis was reported. RESULTS: In total, 32 patients developed NIV failure, nine within 2 hours of NIV and remaining in next 6 days. The ∆TDI cut-off that predicted NIV failure (DD-CC) at T1 was ≤19.04% (area under the curve [AUC], 0.73; sensitivity, 50%; specificity, 85.71%; accuracy; 66.67%), while that at T2 was ≤35.3% (AUC, 0.75; sensitivity, 95.65%; specificity, 57.14%; accuracy, 74.51%; hazard ratio, 19.55). The NIV failure rate was 35.1% in those with normal diaphragmatic function by PC (T2) versus 5.9% by CC (T2). The odds ratio for NIV failure with DD criteria ≤35.3 and <20 at T2 was 29.33 and 4.61, while that for ≤19.04 and <20 at T1 was 6, respectively. CONCLUSIONS: The DD criterion of ≤35.3 (T2) had a better diagnostic profile compared to baseline and PC in prediction of NIV failure.

Accuracy of non-invasive haemoglobin measurements in patients undergoing transurethral resection of prostate surgery.

BACKGROUND AND AIMS: The aim of this study was to evaluate the accuracy of non-invasive haemoglobin (SpHb) compared to laboratory venous haemoglobin (tHb) measurements among patients undergoing elective transurethral resection of prostate (TURP) surgery under spinal anaesthesia. METHODS: In a prospective, observational, outcome-assessor blinded, cohort trial, we enroled 50 American Society of Anesthesiologists physical status (ASA-PS) I-II patients with benign prostatic hyperplasia. The primary outcome included SpHb and tHb measurements performed at four perioperative time-points: just before initiating the fluid preload (T1), and at 30 min (T2), 1 h (T3), and 2 h (T4) after starting the prostate resection, respectively. Statistical tool included intra-class correlation (ICC), Bland-Altman plots, and linear regression analysis. RESULTS: We collected 200 SpHb/tHb data sets from 50 patients. The SpHb had a non-significant negative bias of -0.83 g/dL, -0.43 g/dL, -0.81 g/dL, and -0.46 g/dL, with limits of agreement of 2.6 g/dL to -4.2 g/dL, 2.4 g/dL to -3.3 g/dL, 1.3 g/dL to -2.8 g/dL, and 1.4 g/dL to -2.3 g/dL, for T1 to T4, respectively. The SpHb/tHb pairs correlated significantly (time-dependent increase in ICC from T1 to T4). The SpHb-tHb difference correlated significantly with corresponding serum sodium (T1 to T3), but not with perfusion index. No correlation existed between % change in SpHb-tHb difference (T1 to T4), and intraoperative blood loss or perioperative weight gain. CONCLUSION: The SpHb exhibited a clinically acceptable negative bias compared to tHb during TURP surgery. Although a wide limit of agreement between the SpHb/tHb pairs is a limitation, the real-time SpHb trends can still serve in clinical judgement.