Positive end-expiratory pressure (PEEP) increment induces a decrease in Stroke Volume Index (SVI). We hypothesized that the magnitude of SVI reduction due to a 5 cmH2O increase in PEEP could predict fluid responsiveness during low tidal volume ventilation. Forty-eight patients completed the study. Heart rate, mean arterial pressure, SVI, pulse pressure variation (PPV) and stroke volume variation (SVV) were recorded before short-time low PEEP (SLPC) challenge (applied additional 5 cmH2O PEEP to patients for 30 seconds), during SLPC and before and after 500 mL fluid loading. Patients whose SVI increased more than 15% after the fluid loading were defined as volume responders. Twenty-one (44%) patients were volume responder. Decrease percentage in SVI during SLPC was 17.4±3.6% and 9.9±3.1% in responders and non-responders respectively (P<0.001). A strong correlation was found between decrease percentage in SVI during SLPC and increase percentage in SVI after fluid loading (R2=0.680, P<0.001). The area under receiver operating curves generated to predict fluid responsiveness for decrease percentage in SVI during SLPC (0.944, 95% CI: 0.836-0.990) was significantly higher than that for PPV (0.777, 95% CI: 0.634-0.884, P=0.025) and SVV (0.773, 95% CI: 0.630-0.882, P=0.022). Best cut-off values of decrease percentage in SVI during SLPC was -14.2 with 95% sensitivity and 89% specificity. SVI change percentage during SLPC can predict fluid responsiveness better than PPV and SVV in neurosurgery patients ventilated with low tidal volume.

BACKGROUND: Pulse pressure variation (PPV) and stroke volume variation (SVV) can predict fluid responsiveness effectively. However, high Body Mass Index (BMI) can restrict their use due to changes in respiratory system compliance (CS), intra-abdominal pressure, and stroke volume (SV) in the prone position. Therefore. we aimed to investigate the effectiveness of mini-fluid challenge (MFC) in predicting fluid responsiveness in obese (BMI >= 30 kg/m(2)) patients in the prone position. METHODS: A total of 33 patients undergoing neurosurgery were included. After standardized anesthesia induction, patients' PPV, SVV, stroke volume index (SVI) and CS values were recorded in the prone position (T1), after the infusion of 100 mL of crystalloid named as MFC (T2) and after fluid loading was completed with additional 400 mL of crystalloid. Patients whose SVI increased more than 15% after the fluid loading were defined as volume responders. RESULTS: Fifteen (45%) patients were responders to 500 mL fluid loading. After the 100 mL fluid load, a higher percentage increase in SVI was observed among responders (P<0.001), with values of 6.6% (6.2-8.6%) and 3.5% (1.7-4.8%) in responders and non-responders, respectively. Areas under the receiver operating characteristic curves of MFC, PPV, and SVV were 0.967 (95% CI: 0.838-0.999), 0.683 (95% CI: 0.499-0.834), and 0.709 (95% CI: 0.526-0.853), respectively. The area under the curve of MFC was significantly higher than that of PPV (P = 0.003) and SVV (P=0.005). CONCLUSIONS: The increase in SVI after a rapid infusion of 100 mL crystalloid could predict fluid responsiveness in patients with BMI >= 30 kg/m(2) in the prone position.

Background/aim: The aim of this study was to determine the incidence of residual neuromuscular block (RNMB) in a tertiary care hospital. Secondary goals were to examine the characteristics of the use of intraoperative neuromuscular monitoring (NMM) and different reversal agents by the attending anesthesiologists, and to determine the factors related to the patient and perioperative processes on the development of RNMB. Materials and methods: The patients? arrival time at the postanesthesia care unit was accepted as point zero (T0). The acceleromyography of the patients? adductor pollicis muscle was monitored for NMM. Train of four ratios (TOFRs) were recorded at 0, 10, 20, and 30 min. A TOFR < 0.9 was defined as RNMB. Patients? demographic and perioperative data were also recorded. Results: A total of 216 patients completed the study. RNMB was observed in 47 patients (21.8%). Seventy-eight patients (36%) were followed up with NMM. Neostigmine and sugammadex were used in 174 (80.5%) and 42 (19.5%) patients, respectively, and they were both underdosed (21.2 ± 3.0 mcg/kg and 1.5 ± 0.7 mg/kg, respectively). Use of neostigmine and absence of NMM were risk factors for RNMB (p: 0.01 and 0.001, respectively) along with the number of additional doses (>1 doses, p ? 0.02) and the timing of the last dose of rocuronium (<88 min, p ? 0.01). None of the patients who received both NMM and sugammadex experienced RNMB. Conclusion: The RNMB incidence was found to be 21.8%. The main reasons of it were the lack of intraoperative NMM and inappropriate use of reversal agents. Despite strong recommendations, the use of NMM is still insufficient and reversal agents are still underdosed.