A high risk of sleep apnea is associated with less postoperative cognitive dysfunction after intravenous anesthesia: results of an observational pilot study.

BACKGROUND: The obstructive sleep apnea syndrome (OSAS) is characterized by temporary cerebral hypoxia which can cause cognitive dysfunction. On the other hand, hypoxia induced neurocognitive deficits are detectable after general anesthesia. The objective of this study was to evaluate the impact of a high risk of OSAS on the postoperative cognitive dysfunction after intravenous anesthesia. METHODS: In this single center trial between June 2012 and June 2013 43 patients aged 55 to 80 years with an estimated hospital stay of at least 3 days undergoing surgery were enrolled. Patients were screened for a high risk of OSAS using the STOP-BANG test. The cognitive function was assessed using a neuropsychological test battery, including the DemTect test for cognitive impairment and the RMBT test for memory, the day before surgery and within 36 h after extubation. RESULTS: Twenty-two of the 43 analyzed patients were identified as patients with a high risk of OSAS. Preoperatively, OSAS patients showed a significant worse performance only for the DemTect (p = 0.0043). However, when comparing pre- and postoperative test results, the OSAS patients did not show a significant loss in any test but significantly improved in RMBT test, whereas the control group showed a significant worse performance in three of eight tests. In five tests, we found a significant difference between the two groups with respect to the change from pre- to postoperative cognitive function. CONCLUSION: Patients with a high risk of OSAS showed a less impairment of memory function and work memory performance after intravenous anesthesia. This might be explained by a beneficial effect of intrinsic hypoxic preconditioning in these patients.

Algorithmic Summaries of Perioperative Blood Pressure Fluctuations.

Automated perioperative measurements such as cardiovascular monitoring data are commonly compared to established upper and lower thresholds, but could also allow for more complex interpretations. Analyzing such time series in extensive electronic medical records for research purposes may itself require customized automation, so we developed a set of algorithms for quantifying different aspects of temporal fluctuations. We implemented conventional measures of dispersion, summaries of absolute gradients between successive values, and Poincaré plots. We aggregated the severity and duration of hypotensive episodes by calculating the average area under different mean arterial pressure (MAP) thresholds. We applied these methods to 30,452 de-identified MAP series, and analyzed the similarity between alternative indices via hierarchical clustering. To explore the potential utility of these propositional metrics, we computed their statistical association with presumed complications due to cardiovascular instability. We observed that hierarchical clustering reliably segregated features that had been designed to quantify dissimilar aspects. Summaries of temporary hypotension turned out to be significantly increased among patient subgroups with subsequent signs of a complicated recovery. These associations were even stronger for measures that were specifically geared to capturing short-term MAP variability. These observations suggest the potential capability of our proposed algorithms for quantifying heterogeneous aspects of short-term MAP fluctuations. Future research might also target a wider selection of outcomes and other attributes that may be subject to intraoperative variability.

Competency in managing cardiac arrest: A scenario-based evaluation of dental students.

OBJECTIVE: Advanced Cardiovascular Life Support (ACLS) in life-threatening situations is perceived as a basic skill for dental professionals. However, medical emergency training in dental schools is often not standardized. The dental students' knowledge transfer to an ACLS setting thus remains questionable. The aim of the study was to evaluate dental pre-doctorate students' practical competence in ACLS in a standardized manner to enable the curriculum to be adapted to meet their particular needs. MATERIALS AND METHODS: Thirty dental students (age 25.47 ± 1.81; 16 male/14 female) in their last year of dental studies were randomly assigned to 15 teams. Students' ability to successfully manage ACLS was assessed by a scenario-based approach (training module: Laerdal® ALS Skillmaster). Competence was assessed by means of (a) an observation chart, (b) video analysis and (c) training module analysis (Laerdal HeartSim®4000; Version 1.4). The evaluation was conducted by a trained anesthesiologist with regard to the 2010 guidelines of the European Resuscitation Council (ERC). RESULTS: Only five teams (33.3%) checked for all three vital functions (response, breathing and circulation). All teams initiated cardiopulmonary resuscitation (CPR). Only 54.12% of the compressions performed during CPR were sufficient. Four teams stopped the CPR after initiation. In total, 93% of the teams used the equipment for bag-valve-mask ventilation and 53.3% used the AED (Automated external defibrillator). CONCLUSIONS: ACLS training on a regular basis is necessary and, consistent with a close link between dentistry and medicine, should be a standardized part of the medical emergency curriculum for dental students with a specific focus on the deficiencies revealed in this study.

Intravenous morphine consumption in outpatients with cancer during their last week of life--an analysis based on patient-controlled analgesia data.

INTRODUCTION: Studies on opioid use in terminally ill cancer patients have shown a prefinal dose increase in the majority of patients. Mostly oral opioids were used. Due to the pharmacokinetic properties of opioids, it is rather difficult to get a reliable estimate of the true opioid need from those results. MATERIALS AND METHODS: Retrospectively, we analyzed opioid use during the last week of life of 30 consecutive outpatients with cancer on intravenous (i.v.) morphine patient-controlled analgesia (PCA). A dose increase (decrease) was defined as an increase (decrease) of the patient's individual daily dose by at least 30% with respect to their prior daily dose. We also analyzed circadian variations in morphine use. RESULTS: Thirty patients fulfilled the primary study inclusion criteria. Fulfilling the exclusion criteria, seven patients had to be excluded from analysis (n = 3, on PCA for less than 7 days; n = 4, PCA was finished before death). Twenty-three patients with a total of 161 treatment days were analyzed. The patients' median age was 57 years (range, 4 to 72). The median duration of intravenous morphine PCA was 19 days (range, 8 to 58). The median daily intravenous morphine dose during the last week of life was 96 to 115 mg, without significant change over time/from day to day (Friedman test). On 144/161 days (89.2%), morphine dose remained stable. On 9 treatment days (5.6%), the dose increased, and on 8 days (5.0%), it decreased. In three patients, only dose increases, and in four patients, only dose decreases were observed. In four patients, both dose increases and decreases were observed. Twelve patients showed no change in daily morphine dose. Opioid use lacked a diurnal pattern. CONCLUSION: During their end-of-life phase, cancer patients on i.v. morphine PCA showed a stable daily opioid need.

Milrinone combined with vasopressin improves cardiac index after cardiopulmonary resuscitation in a pig model of myocardial infarction.

BACKGROUND: Milrinone used for acute cardiac insufficiency could be of interest during cardiopulmonary resuscitation because of its positive inotropic effects. In this study, the combination of milrinone-vasopressin was compared with epinephrine and vasopressin, as well as with the combination of epinephrine-vasopressin, in reference to hemodynamics. METHODS: Thirty-two pigs underwent ligation of the circumflex coronary artery and induction of ventricular fibrillation lasting for 4 min. Cardiopulmonary resuscitation was performed after randomization to one of four groups: epinephrine (30-microg/kg bolus), vasopressin (0.4-U/kg bolus), epinephrine-vasopressin (15-microg/kg epinephrine bolus, 0.2-U/kg vasopressin bolus), or milrinone-vasopressin (0.4-U/kg vasopressin bolus, 50-microg/kg milrinone bolus over 5 min and a continuous infusion of 0.4 microg.kg.min). The hemodynamic variables were measured before cardiopulmonary resuscitation as well as 4, 8, 15, and 30 min after return of spontaneous circulation. RESULTS: All animals were resuscitated successfully. The animals of the milrinone-vasopressin group displayed significantly (P<0.05) higher cardiac index values (30 min after return of spontaneous circulation: epinephrine, 65.8+/-13.2; vasopressin, 70.7+/-18.3; epinephrine-vasopressin, 69.1+/-36.2; milrinone-vasopressin, 120.7+/-34.8 ml.min.kg) without a decrease in mean arterial pressure or coronary perfusion pressure. CONCLUSIONS: The combination of vasopressin-milrinone as compared with epinephrine during cardiopulmonary resuscitation leads to an improved cardiac index without relevant decrease of mean arterial pressure or coronary perfusion pressure.