Peripheral perfusion index as a predictor of reintubation in critically ill surgical patients.

PURPOSE: We aimed to evaluate the ability of the peripheral perfusion index (PPI) to predict reintubation of critically ill surgical patients. METHODS: This prospective observational study included mechanically ventilated adults who were extubated after a successful spontaneous breathing trial (SBT). The patients were followed up for the next 48 h for the need for reintubation. The heart rate, systolic blood pressure, respiratory rate, peripheral arterial oxygen saturation (SpO2), and PPI were measured before-, at the end of SBT, 1 and 2 h postextubation. The primary outcome was the ability of PPI 1 h postextubation to predict reintubation using area under the receiver operating characteristic curve (AUC) analysis. Univariate and multivariate analyses were performed to identify predictors for reintubation. RESULTS: Data from 62 patients were analysed. Reintubation occurred in 12/62 (19%) of the patients. Reintubated patients had higher heart rate and respiratory rate; and lower SpO2 and PPI than successfully weaned patients. The AUC (95%confidence interval) for the ability of PPI at 1 h postextubation to predict reintubation was 0.82 (0.71-0.91) with a negative predictive value of 97%, at a cutoff value of ≤ 2.5. Low PPI and high respiratory rate were the independent predictors for reintubation. CONCLUSION: PPI early after extubation is a useful tool for prediction of reintubation. Low PPI is an independent risk factor for reintubation. A PPI > 2.5, one hour after extubation can confirm successful extubation.

The Novel Use of Point-of-Care Ultrasound to Predict Resting Energy Expenditure in Critically Ill Patients.

OBJECTIVES: Accurate estimation of a critically ill patient's caloric requirements is essential for a proper nutritional plan. This study aimed to evaluate the use of point-of-care ultrasound (US) to predict the resting energy expenditure (REE) in critically ill patients. METHODS: In 69 critically ill patients, we measured the REE using indirect calorimetry (REE_IC), muscle layer thicknesses (MLTs), and cardiac output (CO). Muscle thickness was measured at the biceps and the quadriceps muscles. Patients were randomly split into a model development group (n = 46) and a cross-validation group (n = 23). In the model development group, a multiple regression analysis was applied to generate REE using US (REE_US) values. In the cross-validation group, REE was calculated by the REE_US and the resting energy expenditure using the Harris-Benedict equation (REE_HB), and both were compared to the REE_IC. RESULTS: In the model development group, the REE_US was predicted by the following formula: predicted REE_US (kcal/d) = 206 + 173.5 × CO (L/min) + 137 × MLT (cm) - 230 × (women = 1; men = 0) (R2  = 0.8; P < .0001). In the cross-validated group, the REE_IC and REE_US values were comparable (mean difference, -66 [-3.3%] kcal/d; P = .14). However, the difference between the mean REE_IC and the mean REE_HB was 455.8 (26%) kcal/d (P < .001). According to a Bland-Altman analysis, the REE_US agreed well with the REE_IC, whereas the REE_HB did not. CONCLUSIONS: Resting energy expenditure could be estimated from US measurements of MLTs and CO. Our point-of-care US model explains 80% of the change in the REE in critically ill patients.

Evaluation of peripheral perfusion index and heart rate variability as early predictors for intradialytic hypotension in critically ill patients.

BACKGROUND: Intradialytic hypotension is a serious complication during renal replacement therapy in critically ill patients. Early prediction of intradialytic hypotension could allow adequate prophylactic measures. In this study we evaluated the ability of peripheral perfusion index (PPI) and heart rate variability (HRV) to predict intradialytic hypotension. METHODS: A prospective observational study included 36 critically ill patients with acute kidney injury during their first session of intermittent hemodialysis. In addition to basic vital signs, PPI was measured using Radical-7 (Masimo) device. Electrical cardiometry (ICON) device was used for measuring cardiac output, systemic vascular resistance, and HRV. All hemodynamic values were recorded at the following time points: 30 min before the hemodialysis session, 15 min before the start of hemodialysis session, every 5 min during the session, and 15 min after the conclusion of the session. The ability of all variables to predict intradialytic hypotension was assessed through area under receiver operating characteristic (AUROC) curve calculation. RESULTS: Twenty-three patients (64%) had intradialytic hypotension. Patients with pulmonary oedema showed higher risk for development of intradialytic hypotension {Odds ratio (95% CI): 13.75(1.4-136)}. Each of baseline HRV, and baseline PPI showed good predictive properties for intradialytic hypotension {AUROC (95% CI): 0.761(0.59-0.88)}, and 0.721(0.547-0.857)} respectively. CONCLUSIONS: Each of low PPI, low HRV, and the presence of pulmonary oedema are good predictors of intradialytic hypotension.

Evaluation of the effects of dexmedetomidine infusion on oxygenation and lung mechanics in morbidly obese patients with restrictive lung disease.

BACKGROUND: Dexmedetomidine infusion improves oxygenation and lung mechanics in patients with chronic obstructive lung disease; however, its effect in patients with restrictive lung disease has not been thoroughly investigated yet. The aim of this work was to evaluate the effects of dexmedetomidine infusion on oxygenation and lung mechanics in morbidly obese patients with restrictive lung disease. METHODS: Forty-two morbidly obese patients scheduled for bariatric surgery were included in the study. Patients were randomized to receive either dexmedetomidine infusion at a bolus dose of 1mcg/Kg followed by infusion at 1 mcg/Kg/hour for 90 min (Dexmedetomidine group), or normal saline infusion (Control group). Both groups were compared with regard to: oxygenation {P/F ratio: PaO2/fraction of inspired oxygen (FiO2)}, lung compliance, dead space, plateau pressure, blood pressure, and heart rate. RESULTS: Dexmedetomidine group showed significant improvement of the PaO2/FiO2 ratio, and higher lung compliance compared to control group by the end of drug infusion. Dexmedetomidine group demonstrated decreased dead space, plateau pressure, blood pressure, and heart rate compared to control group by the end of drug infusion. CONCLUSION: A 90-min dexmedetomidine infusion resulted in moderate improvement in oxygenation and lung mechanics in morbidly obese patients with restrictive lung disease. TRIAL REGISTRATION: clinicaltrials.gov : NCT02843698 on 20 July 2016.

Perfusion index-derived parameters as predictors of hypotension after induction of general anaesthesia: a prospective cohort study.

BACKGROUND: Induction of general anaesthesia is commonly associated with hypotension. This exposes patients to perioperative organ hypoperfusion and eventually damage. This study was designed to assess the ability of preoperative perfusion index (PI), plethysmographic variability index (PVI), and dicrotic plethysmography (Dicpleth) to predict hypotension after induction of general anaesthesia. METHODS: In this cohort study, 95 ASA I and II adult patients who were scheduled for elective surgery under general anaesthesia were enrolled. The correlation between preoperative PI, PVI, Dicpleth and percentage decrease in mean arterial blood pressure after anaesthesia induction was investigated. Ability of PI, PVI, Dicpleth to detect post-induction hypotension was also analysed. RESULTS: The percent decrease in MAP after anaesthesia correlated with baseline PI (r = -0.45, P < 0.001), PVI (r = 0.45, P = 0.001) and Dicpleth (r = 0.16, P = 0.12). The PI cut-off value was ≤ 3.03 for a patient at risk for post-induction hypotension with 77.8% sensitivity, 75% specificity, positive and negative predictive values of 74.5% and 78.3%, respectively. Similarly, the ROC analysis revealed that baseline PVI (AUC = 0.73, 95% CI = 0.622-0.812) was suitable for detecting post-induction hypotension. Moreover, baseline Dicpleth (AUC = 0.63) showed significant predictive ability. CONCLUSIONS: The pre-anaesthetic PI and PVI 17, respectively, have a good ability to predict those at risk of developing post-induction hypotension in adult patients undergoing elective surgery under general anaesthesia. Future studies are needed in order to investigate the usefulness of Dicpleth in different circumstances during anaesthesia. Clinical trial registration ID: The study was registered at clinicaltrials.gov (NCT04217226).