The effect of perioperative anesthetics for prevention of postoperative delirium on general anesthesia: A network meta-analysis.

STUDY OBJECTIVE: Postoperative delirium (POD) is a common neurological system disorder in surgical patients. Anesthesia providers have a wide choice of sedative agents involving different mechanisms in clinical practice, and the incidence of POD varies regarding which sedative agent administered. This network meta-analysis aimed to comprehensively analyze the safety and efficacy of each choice for patients. DESIGN: A network meta-analysis. SETTING: Vanderbilt University Medical Center. MEASUREMENTS: We searched PubMed, EMBASE, Ovid Medline and Cochrane Central Register of Controlled Trials (CENTRAL) through the end of September 2018 with the registration number CRD42018110585. The randomized controlled trials were identified and extracted by two reviewers independently. Commonly used sedative agents such as placebo, sevoflurane, desflurane, isoflurane, dexmedetomidine, propofol, midazolam, and ketamine were assessed in this network meta-analysis and the primary outcome was the incidence of POD. The data were synthesized by network meta-analysis. Pair-wise meta-analyses were conducted using the random-effects model. Each intervention was ranked according to its corresponding surface under the cumulative ranking curve (SUCRA) values. The GRADE framework was undertaken to evaluate the risk of bias. MAIN RESULTS: We identified 39 RCTs and 5991 patients in this meta-analysis. Dexmedetomidine was found to be the most effective option in reducing POD, compared to midazolam, propofol, desflurane, and sevoflurane. The results revealed that dexmedetomidine was associated with a lower incidence of POD, whereas midazolam was associated with a significantly higher number of patients with delirium. Midazolam and propofol were also associated with a higher incidence of perioperative hypotension and bradycardia. CONCLUSION: Our study provided meta-analytic evidence and suggested dexmedetomidine could be considered as the most effective sedative agent to reduce POD. However, clinical practitioners still need to weigh the pros and cons before choosing a sedative agent for individual patient.

Comparison of a simplified nasal continuous positive airways pressure device with nasal cannula in obese patients undergoing colonoscopy during deep sedation: A randomised clinical trial.

BACKGROUND: Continuous positive airways pressure (CPAP) with a CPAP machine and mask has been shown to be more effective at minimising hypoxaemia than other devices under deep sedation. However, the efficacy of a new and simple CPAP device for spontaneously breathing obese patients during colonoscopy is unknown. OBJECTIVE: We hypothesised that oxygenation and ventilation in obese patients under deep sedation during colonoscopy using CPAP via a new nasal mask (SuperNO2VA) would be better than routine care with oxygen supplementation via a nasal cannula. DESIGN: Randomised study. SETTING: Single-centre, June 2017 to October 2017. PATIENTS: A total of 174 patients were enrolled and randomly assigned to Mask group or Control group. Thirty-eight patients were excluded and data from 136 patients underwent final analysis. INTERVENTION: Patients in the Mask group were provided with nasal CPAP (10 cmH2O) at an oxygen flow rate of 15 l min. In the Control group, patients were given oxygen via a nasal cannula at a flow rate of 5 l min. MAIN OUTCOME MEASURES: The primary outcome was elapsed time from anaesthesia induction to the first airway intervention. RESULTS: The elapsed time from anaesthesia induction to the first airway intervention was 19 ±â€Š10 min in the Mask group (n=63) vs. 10 ±â€Š12 min in the Control group (n=73, P < 0.001). In all, 87.5% (56/64) of patients achieved the target CPAP value. More patients in the Control group (63%) received airway intervention than in the Mask group (22%) (P < 0.001). Hypoxaemia (pulse oximeter oxygen saturation, SpO2 < 90%) occurred more frequently in the Control group (22%) than in the Mask group (5%) (P = 0.004). Minute ventilationPostinduction/minute ventilationBaseline and minute ventilationProcedure-end/minute ventilationBaseline was lower in the Control group than in the Mask group (P = 0.007 and 0.001, respectively). CONCLUSION: Application of a nasal mask at a target CPAP of 10 cmH2O improves ventilation and decreases the frequency and severity of hypoxaemia. TRIAL REGISTRATION: NCT03139448, registered at ClinicalTrials.gov.

Compliance Is Contagious: Using Informatics Methods to Measure the Spread of a Documentation Standard From a Preoperative Clinic.

PURPOSE: Preoperative documentation is essential to coordinated care and has the potential for standardization, which may facilitate downstream clinical management. DESIGN: An observational pre/post standardization design was used. METHODS: We analyzed the implementation of a preoperative documentation standardization intervention in Vanderbilt's Preoperative Evaluation Clinic (VPEC) and its impact outside VPEC. A phased intervention consisted of clinician education with monthly feedback, followed by the development of a compliance dashboard and inclusion in Ongoing Professional Performance Evaluation system by VPEC. A follow-up survey was administered to measure the impact on clinical management. FINDINGS: Adherence to standardization was improved with the addition of electronic feedback. Implementation of this system in the preoperative clinic had significant impact outside VPEC. Trainee status was a significant predictor of adoption of the standardized format. CONCLUSIONS: Adoption of a preoperative documentation standard in a clinic had a positive impact on standardization practices in a perioperative system.

The Effects of Dexmedetomidine on Microelectrode Recordings of the Subthalamic Nucleus during Deep Brain Stimulation Surgery: A Retrospective Analysis.

BACKGROUND: The placement of subthalamic nucleus (STN) deep brain stimulation (DBS) electrodes can be facilitated by intraoperative microelectrode recording (MER) of the STN. OBJECTIVES: Optimal anesthetic management during surgery remains unclear because of a lack of quantitative data of the effect of anesthetics on MER. Therefore, we measured the effects of dexmedetomidine (DEX) on MER measures of the STN commonly taken intraoperatively. METHODS: MER from 45 patients was retrospectively compared between patients treated with remifentanil (REMI) alone or both REMI and DEX, which are the 2 main standards of care at our center. The measures examined were population activity, such as root mean square, STN length, and number of passes yielding STN, and the single-neuron measures of firing rate and variability. RESULTS: The addition of DEX does not affect population measures (number of passes: DEX+REMI, n = 68, REMI only, n = 154), or neuronal firing rates (number of neurons: DEX+REMI, n = 64, REMI only, n = 72), but firing rate variability was reduced. CONCLUSIONS: In this cohort, population-based measures routinely used for electrode placement in the STN were unaffected by DEX when added to REMI. Neuronal firing rates were also unaffected, but their variability was reduced, even beyond 20 min after cessation.

Perioperative visual loss.

Perioperative visual loss is an infrequent, devastating complication associated with spine surgery, most commonly from ischemic optic neuropathy. Current research and expert opinion indicate that it is associated with procedures that create elevated venous pressure in the head for prolonged periods of time. The largest case-control study on ischemic optic neuropathy associated with spine surgery found six independent and significant risk factors including male sex, obesity, Wilson frame use, longer operative times, greater blood loss, and a lower colloid to crystalloid ratio in the non-blood fluid administration. The American Society of Anesthesiologists developed a practice advisory for the prevention of this complication. In this setting, it is advisable to avoid significant physiologic and hemodynamic perturbations as much as possible, given the uncertainty of the pathophysiology. Because prevention of this complication cannot be guaranteed, consent for perioperative visual loss should be strongly considered in patients at high risk for this complication.

Measuring and Improving First Case On-Time Starts and Analysis of Factors Predicting Delay in Neurosurgical Operating Rooms.

BACKGROUND: We undertook an operating room (OR) process improvement project to increase first case on-time starts (FCOTS) in the neurosurgical ORs at a tertiary care academic medical center. We engaged the neurosurgical perioperative team which included neurosurgeons, neuroanesthesiologists, and nurses in a shared goal of improving FCOTS. METHODS: Our project involved hiring a new service manager and a focused shared effort on improving FCOTS. After project completion, we conducted a retrospective analysis of FCOTS in 6 neurosurgical ORs. If patients were not in the OR within 5 minutes of scheduled start time, it was considered a late start. Factors predicting delayed start were also identified. During the same period, first cases performed outside the neurosurgical ORs served as a control group. RESULTS: A total of 2328 elective neurosurgical cases were evaluated. The baseline FCOTS from November 2009 to March 2010 was 33%. The first performance shift occurred during March 2010 to January 2011 when FCOTS increased to 44%. In the second performance shift between January 2011 and November 2011 during the implementation phase of this quality improvement project, FCOTS rose to 68% and has continued to increase. Multivariate logistic regression analysis identified the following as significant predictors of delayed start: female sex (odds ratio [OR]=0.771; 95% confidence interval [CI], 0.599-0.943), certified registered nurse anesthetists on the case (OR=0.750; 95% CI, 0.576-0.924), cases done on Friday (OR=0.551; 95% CI, 0.312-0.791), and American Society of Anesthesiologists status IV (OR=0.530; 95% CI, 0.157-0.903). CONCLUSION: The quality improvement project, which was implemented in 2 phases, successfully increased the FCOTS rate in our neurosurgical ORs from 33% to 68%.

Kinetic parameters and lactate dehydrogenase isozyme activities support possible lactate utilization by neurons.

Lactate is potentially a major energy source in brain, particularly following hypoxia/ischemia; however, the regulation of brain lactate metabolism is not well understood. Lactate dehydrogenase (LDH) isozymes in cytosol from primary cultures of neurons and astrocytes, and freshly isolated synaptic terminals (synaptosomes) from adult rat brain were separated by electrophoresis, visualized with an activity-based stain, and quantified. The activity and kinetics of LDH were determined in the same preparations. In synaptosomes, the forward reaction (pyruvate + NADH + H(+ )--> lactate + NAD(+)), which had a V (max) of 1,163 micromol/min/mg protein was 62% of the rate in astrocyte cytoplasm. In contrast, the reverse reaction (lactate + NAD(+ )--> pyruvate + NADH + H(+)), which had a V (max) of 268 micromol/min/mg protein was 237% of the rate in astrocytes. Although the relative distribution was different, all five isozymes of LDH were present in synaptosomes and primary cultures of cortical neurons and astrocytes from rat brain. LDH1 was 14.1% of the isozyme in synaptic terminals, but only 2.6% and 2.4% in neurons and astrocytes, respectively. LDH5 was considerably lower in synaptic terminals than in neurons and astrocytes, representing 20.4%, 37.3% and 34.8% of the isozyme in these preparations, respectively. The distribution of LDH isozymes in primary cultures of cortical neurons does not directly reflect the kinetics of LDH and the capacity for lactate oxidation. However, the kinetics of LDH in brain are consistent with the possible release of lactate by astrocytes and oxidative use of lactate for energy in synaptic terminals.