Effects of Tibetan Music on Neuroendocrine and Autonomic Functions in Patients Waiting for Surgery: A Randomized, Controlled Study.

BACKGROUND: The aim of this study was to investigate the effects of listening to Tibetan music on anxiety and endocrine, autonomic, cognitive responses in patients waiting for urologic surgery. METHODS: Sixty patients waiting for surgery were enrolled to the study. They were randomized in music (M) and control (C) groups. The M group listened to a low-frequency Tibetan music for 30 min (T0-T30) through headphones, and the C group wore headphones with no sound. The State Trait Anxiety Inventory Questionnaire (STAI) Y-1 was administered at T0 and T30. Normalized low (LFnu) and high frequencies (HFnu) of heart rate variability, LF/HF ratio, and galvanic skin response (GRS) data were analyzed at T0, T10, T20, T30, and T35. The salivary α-amylase (sAA) samples were collected at T0, T35, and T45. RESULTS: In the M group, the STAI Y-1 score decreased at T30 versus baseline (p < 0.001), sAA levels decreased at T35 versus T0(p=0.004), and GSR remained unchanged. In the C group, the STAI Y-1 score remained unchanged, sAA level increased at T35 versus T0(p < 0.001), and GSR slightly increased at T35 versus baseline (p=0.359). LFnu was lower, and HFnu was significantly higher (T10-T30) in M versus C group. Mean LF/HF ratio slightly reduced in the M group. CONCLUSIONS: Our results suggest that preoperative listening to relaxing Tibetan music might be a useful strategy to manage preoperative anxiety.

Physiological effects of the open lung approach during laparoscopic cholecystectomy: focus on driving pressure.

BACKGROUND: During laparoscopy, respiratory mechanics and gas exchange are impaired because of pneumoperitoneum and atelectasis formation. We applied an open lung approach (OLA) consisting in lung recruitment followed by a decremental positive-end expiratory pressure (PEEP) trial to identify the level of PEEP corresponding to the highest compliance of the respiratory system (best PEEP). Our hypothesis was that this approach would improve both lung mechanics and oxygenation without hemodynamic impairment. METHODS: We studied twenty patients undergoing laparoscopic cholecystectomy. We continuously recorded respiratory mechanics parameters throughout a decremental PEEP trial in order to identify the best PEEP level. Furthermore, lung and chest wall mechanics, respiratory and transpulmonary driving pressures (ΔP), gas exchange and hemodynamics were recorded at three time-points: 1) after pneumoperitoneum induction (TpreOLA); 2) after the application of the OLA (TpostOLA); 3) at the end of surgery, after abdominal deflation (Tend). RESULTS: The "best PEEP" level was 8.1±1.3 cmH2O (range 6 to 10 cmH2O), corresponding to the highest compliance of the respiratory system (CRS). This "best PEEP" level corresponded with lowest ΔPL. OLA increased the compliance of the lung and of the chest wall, and decreased ΔPRS and ΔPL. PaO2/FiO2 increased from 299±125 mmHg to 406±101 mmHg (P=0.04). Changes in respiratory mechanics, driving pressures and oxygenation were maintained until Tend. Hemodynamic parameters remained stable throughout the study period. CONCLUSIONS: In patients undergoing laparoscopic cholecystectomy, the OLA was suitable for bedside PEEP setting, improved lung mechanics and gas exchange without significant adverse hemodynamic effects.

Heart rate variability in critical care medicine: a systematic review.

BACKGROUND: Heart rate variability (HRV) has been used to assess cardiac autonomic activity in critically ill patients, driven by translational and biomarker research agendas. Several clinical and technical factors can interfere with the measurement and/or interpretation of HRV. We systematically evaluated how HRV parameters are acquired/processed in critical care medicine. METHODS: PubMed, MEDLINE, EMBASE and the Cochrane Central Register of Controlled Trials (1996-2016) were searched for cohort or case-control clinical studies of adult (>18 years) critically ill patients using heart variability analysis. Duplicate independent review and data abstraction. Study quality was assessed using two independent approaches: Newcastle-Ottowa scale and Downs and Black instrument. Conduct of studies was assessed in three categories: (1) study design and objectives, (2) procedures for measurement, processing and reporting of HRV, and (3) reporting of relevant confounding factors. RESULTS: Our search identified 31/271 eligible studies that enrolled 2090 critically ill patients. A minority of studies (15; 48%) reported both frequency and time domain HRV data, with non-normally distributed, wide ranges of values that were indistinguishable from other (non-critically ill) disease states. Significant heterogeneity in HRV measurement protocols was observed between studies; lack of adjustment for various confounders known to affect cardiac autonomic regulation was common. Comparator groups were often omitted (n = 12; 39%). This precluded meaningful meta-analysis. CONCLUSIONS: Marked differences in methodology prevent meaningful comparisons of HRV parameters between studies. A standardised set of consensus criteria relevant to critical care medicine are required to exploit advances in translational autonomic physiology.

Effect of age on the performance of bispectral and entropy indices during sevoflurane pediatric anesthesia: a pharmacometric study.

BACKGROUND: Bispectral index (BIS) and entropy monitors have been proposed for use in children, but research has not supported their validity for infants. However, effective monitoring of young children may be even more important than for adults, to aid appropriate anesthetic dosing and reduce the chance of adverse consequences. This prospective study aimed to investigate the relationships between age and the predictive performance of BIS and entropy monitors in measuring the anesthetic drug effects within a pediatric surgery setting. METHODS: We concurrently recorded BIS and entropy (SE/RE) in 48 children aged 1 month-12 years, undergoing general anesthesia with sevoflurane and fentanyl. Nonlinear mixed effects modeling was used to characterize the concentration-response relationship independently between the three monitor indicators with sevoflurane. The model's goodness-of-fit was assessed by prediction-corrected visual predictive checks. Model fit with age was evaluated using absolute conditional individual weighted residuals (|CIWRES|). The ability of BIS and entropy monitors to describe the effect of anesthesia was compared with prediction probabilities (PK ) in different age groups. Intraoperative and awakening values were compared in the age groups. The correlation between BIS and entropy was also calculated. RESULTS: |CIWRES| vs age showed an increasing trend in the model's accuracy for all three indicators. PK probabilities were similar for all three indicators within each age group, though lower in infants. The linear correlations between BIS and entropy in different age groups were lower for infants. Infants also tended to have lower values during surgery and at awakening than older children, while toddlers had higher values. CONCLUSIONS: Performance of both monitors improves as age increases. Our results suggest a need for the development of new monitor algorithms or calibration to better account for the age-specific EEG dynamics of younger patients.