Prewarming Parturients for Cesarean Section Does Not Raise Wound Temperature But Body Heat and Level of Comfort: A Randomized Trial.

PURPOSE: Prewarming before cesarean section lowers the rates of surgical site infections (SSIs). We hypothesized that this effect is explained due to a higher core temperature resulting in a higher wound temperature. DESIGN: We conducted an open-labeled randomized study with on-term parturients scheduled for elective cesarean section under spinal anesthesia. Participants were randomized into an intervention group (prewarming) and a control group. METHODS: Core and wound temperature, comfort level, and examination results were taken at defined times until discharge from the postanesthesia care unit (PACU). There was a follow-up visit and interview 1 day after the procedure. The primary outcome was a difference in wound temperature. The secondary outcomes were differences in core temperature, patient comfort, blood loss, SSI, and neonatal outcome. FINDINGS: We randomized a total of 60 patients, 30 per group. Prewarming lead to a significantly higher core temperature. Additionally, patient comfort was significantly higher in the prewarming group even after discharge from PACU. We did not find a difference in wound temperature, SSI, neonatal outcome, or blood loss. CONCLUSIONS: Prewarming before cesarean section under spinal anesthesia maintains core temperature and improves patient comfort but does not affect wound temperature.

[Lethal Heatstroke with Disseminated Intravascular Coagulopathy]. / Letaler Hitzeschock mit disseminierter intravasaler Koagulopathie.

We report on a case of severe heat stroke due to extended exposure to the sun in an enclosed glass cabin of an agricultural vehicle. Patient treatment, lab results and complications are reported and we examine the current literature on heat stroke.Heat stroke is a very rare and highly severe condition mostly suffered by vulnerable individuals or individuals exposed to extreme physical strain. Per definition a heat stroke is characterized by neurological deficit (especially loss of consciousness), and a high body temperature. Most important treatment is to lower the body temperature below 40 °C as quickly as possible. The best method is cold water immersion, but there are several other physical and invasive means that can be used. If performed within 30 minutes after the beginning of the incident this treatment decreases mortality considerably.Heat damage affects every organ and organ system. Most important are neurologic deficits, cardiovascular failure, liver failure and kidney failure. The excessive heat triggers a systemic inflammatory response syndrome (SIRS) which can lead to a disseminated intravascular coagulopathy (DIC). Haemostasis is also directly affected by the elevated temperature.Besides physical cooling, there is no known specific treatment to prevent secondary damage from heat stroke. Additionally, supportive care and ICU monitoring should be applied.

Recognizing Preventable Death: Is There a Role of Survival Prediction Algorithms?

Monitoring the quality of trauma care is important but particularly challenging. Preventable death assessment aims to identify those cases where the patient's death would have not occurred if the patient had been treated differently. Determination of preventable death in trauma care is often based on calculated probability of survival, commonly by using the Trauma and Injury Severity Score (TRISS). TRISS is not suited for identifying all cases with opportunities for improvement. Combined with other methods such as morbidity and mortality conferences, however, it might be a valid approach if a complete review of all trauma deaths is not feasible at an institution.

Comparison of distribution of lung aeration measured with EIT and CT in spontaneously breathing, awake patients1.

BACKGROUND: Both Electrical Impedance Tomography (EIT) and Computed Tomography (CT) allow the estimation of the lung area. We compared two algorithms for the detection of the lung area per quadrant from the EIT images with the lung areas derived from the CT images. METHODS: 39 outpatients who were scheduled for an elective CT scan of the thorax were included in the study. For each patient we recorded EIT images immediately before the CT scan. The lung area per quadrant was estimated from both CT and EIT data using two different algorithms for the EIT data. RESULTS: Data showed considerable variation during spontaneous breathing of the patients. Overall correlation between EIT and CT was poor (0.58-0.77), the correlation between the two EIT algorithms was better (0.90-0.92). Bland-Altmann analysis revealed absence of bias, but wide limits of agreement. CONCLUSIONS: Lung area estimation from CT and EIT differs significantly, most probably because of the fundamental difference in image generation.

Checklists and Other Cognitive Aids For Emergency And Routine Anesthesia Care-A Survey on the Perception of Anesthesia Providers From a Large Academic US Institution.

BACKGROUND: The use of printed or electronic checklists and other cognitive aids has gained increasing interest from anesthesia providers and professional societies. While these aids are not currently considered standard of care, the perceptions of the clinician might have an impact on their adoption. OBJECTIVES: We conducted a comprehensive survey to study the current opinions of anesthesia provider on the use of checklists and other cognitive aids. PATIENTS AND METHODS: A questionnaire was developed by a departmental checklist focus group, which aimed to identify the perception of health care checklists in general as well as specific checklists for routine and crisis situations in anesthesia. Furthermore participants were asked regarding their perception of performing routine anesthesia and managing crisis situations without any cognitive aids. Using a web-based system, the survey was administered to all anesthesia providers at a single large United States academic medical center (University of California San Francisco). Demographic information included professional status (faculty, anesthesia resident, or nurse anesthetists [certified registered nurse anesthetists; CRNA]) and years of clinical experience. RESULTS: 69% of 312 providers responded. 98% of the survey takers consider the procedural time-out (the widely used pre-incision operating room checklist) as important or very important. We found that many anesthesia providers acknowledged limitations in their ability to perform clinical tasks without any lapses, and a majority would use checklists and other cognitive aids if available. Their acceptances are especially high for crisis situations (87 - 97%, depending on years of experience) and routine care that providers do not perform often (76 - 91%). Printed or electronic aids for patient-care transition and shift hand-offs were also valued (61% and 58%). To prepare for and perform routine anesthesia care, 40% of providers claimed interest in using checklists, however, the interest differed significantly with clinical experience: While both the least and most experienced providers valued aids for routine anesthesia (54% and 50%), only 29% of providers with 2 - 10 years of anesthesia experience claimed interest in using them. Distraction from patient care and decreased efficiency were concerns expressed for the use of routine checklist (27% and 31%, respectively). The main factors found to support the successful implementation of checklists into clinical care are ease of use and thoughtful integration into the anesthesia workflow. CONCLUSIONS: Providers at our large academic institution generally embrace the concept of checklists and other cognitive aids. This was true for all providers for checklists for procedural time outs, anesthesia crisis situations and those for routine procedures that providers rarely perform. Only very experienced and very junior providers appreciated the use of checklists for routine care. There remains a discrepancy between these claims and provider's perception on their clinical competency based on memory alone.

Effect of Trigger Sensitivity on Redistribution of Ventilation During Pressure Support Ventilation Detected by Electrical Impedance Tomography.

BACKGROUND: In supine position, pressure support ventilation causes a redistribution of ventilation towards the ventral regions of the lung. Theoretically, a less sensitive support trigger would cause the patient to breathe more actively, potentially attenuating the effect of positive pressure ventilation. OBJECTIVES: To quantify the effect of trigger setting, we assessed redistribution of ventilation during pressure support ventilation (PSV) using electrical impedance tomography (EIT). PATIENTS AND METHODS: With approval from the local ethics committee, six orthopedic patients were enrolled. All patients had general anesthesia with a laryngeal mask airway and a standardized anesthetic regimen (sufentanil, propofol and sevoflurane). Pressure support trigger settings varied between 2 and 15 L/minute and compared to unassisted spontaneous breathing. From EIT data, the center of ventilation (COV), the fraction of the total ventilation per region of interest (ROI) and intratidal gas distribution were calculated. RESULTS: At all trigger settings, pressure support ventilation caused a significant ventral shift of the center of ventilation compared with during spontaneous breathing, confirmed by the analysis by regions of interest. During spontaneous breathing, COV was not different from baseline values obtained before induction of anesthesia. During PSV, the intratidal regional gas distribution (ITV-analysis) revealed subtle changes during the early inspiratory phase not detected by the COV-analysis. CONCLUSIONS: Pressure support ventilation, but not spontaneous breathing, induces a significant redistribution of ventilation towards the ventral region. The sensitivity of the support trigger appears to influence the distribution of ventilation only during the early phase of inspiration.

Comparison of Two Clinical Protocols for Total Intravenous Anesthesia (TIVA) for Breast Surgery Using Propofol Combined With Either Sufentanil or Alfentanil.

BACKGROUND: Sufentanil and alfentanil have pharmacokinetic and dynamic properties which make them favourable substances for total intravenous anesthesia (TIVA) in combination with propofol. OBJECTIVES: We planned to compare two clinical protocols for TIVA with propofol, and either sufentanil or alfentanil in regards to postoperative pain, hemodynamic stability during the case and time for emergence from anesthesia. PATINETS AND METHODS: Treaty eight patients scheduled for general anesthesia for breast surgery were included in this Double-blind, randomized, controlled trial. All patients received a standardized TIVA with propofol and either 0.2 µg kg(-1) sufentanil or 20 µg kg(-1) alfentanil for induction and 0.3 µg kg(-1) h(-1) sufentanil or 30 µg kg(-1) h(-1) alfentanil for maintenance with additional propofol boluses as needed. During anesthesia, heart rate, non-invasive blood-pressure, peripheral oxygen saturation and depth of anesthesia, were recorded. In the post anesthesia care unit, pain scores, nausea and vomiting as well as medications were recorded. RESULTS: Patients in the sufentanil group required less often additional opioid and propofol boluses to maintain adequate anesthesia. We did not observe a significant difference in time to extubation. Postoperatively, patients in the sufentanil group had less pain (P = 0.03) and required less i.v. opioids (0.4 vs. 1.9 mg piritramid, P = 0.04). CONCLUSIONS: Both protocols provide excellent anesthesia, but patients receiving sufentnail had more stable anesthesia and less postoperative pain.

Efficacy and safety of thromboprophylaxis with low-molecular-weight heparin or rivaroxaban in hip and knee replacement surgery: findings from the ORTHO-TEP registry.

Prospective trials have shown that rivaroxaban thromboprophylaxis is superior over low-molecular-weight heparin (LMWH) in patients undergoing hip and knee replacement surgery. However, patients treated under trial conditions are different from unselected routine patients, which may affect efficacy and safety of thromboprophylaxis. The objective was to evaluate the efficacy and safety of rivaroxaban or LMWH thromboprophylaxis in unselected patients undergoing hip and knee replacement surgery in daily care. In a monocentric, retrospective cohort study in 5,061 consecutive patients undergoing hip and knee replacement surgery a comparison of LMWH (hospital standard in 2006-2007) and rivaroxaban (since 2009) was made with regard to rates of symptomatic VTE, bleeding and surgical complications and length of hospital stay. Rates of symptomatic VTE were 4.1 % (LMWH) and 2.1 % (rivaroxaban; p=0.005) with rates for distal DVT 2.5 vs. 1.1 % (p<0.001). Rates of major VTE were numerically higher with LMWH (1.7 vs. 1.1%, not statistically significant). Rates of major bleeding (overt bleeding leading to surgical revision or death, occurring in a critical site, or transfusion of at least two units of packed red blood cells) were statistically lower with rivaroxaban (2.9 vs. 7.0%; p<0.001). Rivaroxaban patients had fewer surgical complications (1.1 vs. 3.7%; p<0.001) and a shorter length of hospitalisation (8.3 days; 95% CI 8.1- 8.5 vs. 11.1 days; 10.7- 11.5; p< 0.001). We conclude that rivaroxaban thromboprophylaxis is more effective than LMWH in unselected patients undergoing hip and knee replacement surgery in daily care and that switching from LMWH to rivaroxaban could be beneficial. Prospective comparisons are warranted to confirm our findings.

Who is at risk for postdischarge nausea and vomiting after ambulatory surgery?

BACKGROUND: About one in four patients suffers from postoperative nausea and vomiting. Fortunately, risk scores have been developed to better manage this outcome in hospitalized patients, but there is currently no risk score for postdischarge nausea and vomiting (PDNV) in ambulatory surgical patients. METHODS: We conducted a prospective multicenter study of 2,170 adults undergoing general anesthesia at ambulatory surgery centers in the United States from 2007 to 2008. PDNV was assessed from discharge until the end of the second postoperative day. Logistic regression analysis was applied to a development dataset and the area under the receiver operating characteristic curve was calculated in a validation dataset. RESULTS: The overall incidence of PDNV was 37%. Logistic regression analysis of the development dataset (n=1,913) identified five independent predictors (odds ratio; 95% CI): female gender (1.54; 1.22 to 1.94), age less than 50 yr (2.17; 1.75 to 2.69), history of nausea and/or vomiting after previous anesthesia (1.50; 1.19 to 1.88), opioid administration in the postanesthesia care unit (1.93; 1.53 to 2.43), and nausea in the postanesthesia care unit (3.14; 2.44-4.04). In the validation dataset (n=257), zero, one, two, three, four, and five of these factors were associated with a PDNV incidence of 7%, 20%, 28%, 53%, 60%, and 89%, respectively, and an area under the receiver operating characteristic curve of 0.72 (0.69 to 0.73). CONCLUSIONS: PDNV affects a substantial number of patients after ambulatory surgery. We developed and validated a simplified risk score to identify patients who would benefit from long-acting prophylactic antiemetics at discharge from the ambulatory care center.

Spontaneous breathing during general anesthesia prevents the ventral redistribution of ventilation as detected by electrical impedance tomography: a randomized trial.

BACKGROUND: Positive-pressure ventilation causes a ventral redistribution of ventilation. Spontaneous breathing during general anesthesia with a laryngeal mask airway could prevent this redistribution of ventilation. We hypothesize that, compared with pressure-controlled ventilation, spontaneous breathing and pressure support ventilation reduce the extent of the redistribution of ventilation as detected by electrical impedance tomography. METHODS: The study was a randomized, three-armed, observational, clinical trial without blinding. With approval from the local ethics committee, we enrolled 30 nonobese patients without severe cardiac or pulmonary comorbidities who were scheduled for elective orthopedic surgery. All of the procedures were performed under general anesthesia with a laryngeal mask airway and a standardized anesthetic regimen. The center of ventilation (primary outcome) was calculated before the induction of anesthesia (AWAKE), after the placement of the laryngeal mask airway (BEGIN), before the end of anesthesia (END), and after arrival in the postanesthesia care unit (PACU). RESULTS: The center of ventilation during anesthesia (BEGIN) was higher than baseline (AWAKE) in both the pressure-controlled and pressure support ventilation groups (pressure control: 55.0 vs. 48.3, pressure support: 54.7 vs. 48.8, respectively; multivariate analysis of covariance, P < 0.01), whereas the values in the spontaneous breathing group remained at baseline levels (47.9 vs. 48.5). In the postanesthesia care unit, the center of ventilation had returned to the baseline values in all groups. No adverse events were recorded. CONCLUSIONS: Both pressure-controlled ventilation and pressure support ventilation induce a redistribution of ventilation toward the ventral region, as detected by electrical impedance tomography. Spontaneous breathing prevents this redistribution.

Two serial check valves can prevent cross-contamination through intravenous tubing during total intravenous anesthesia.

BACKGROUND: Nonsterile handling of propofol for anesthesia has been linked with severe sepsis and death. Placing a single check valve in the IV tubing does not prevent retrograde ascension of pathogens into propofol-filled syringes, so we designed an IV tubing set with multiple check valves. To estimate the efficacy of this design, we measured the concentration of pathogens detected upstream in the IV tubing in relation to the pathogen concentration in a model of a contaminated patient. METHODS: A glass container with a rubber sealed port was filled with a suspension of either bacteria or phagocytes and kept at 37°C ("contaminated patient" model). A bag of normal saline was connected to an IV cannula, punctured through the rubber sealed port of the patient model. Two additional sidestream infusion lines were connected to syringes in 2 standard infusion pumps. One of the syringes contained propofol and the other contained normal saline as a substitute for an opioid preparation. After 5 hours of infusion, we obtained samples from different parts of the infusion lines and syringes. The samples were streaked out on blood agar plates and incubated at 37°C for 24 hours. We repeated this experiment with 6 different pathogens. RESULTS: We incubated 825 agar plates. Whereas the concentration of bacteria and phagocytes in the "patient" had significantly increased during the 5-hour experiments (positive control), no bacterial growth could be detected in any of the incubated plates. CONCLUSION: The data from this experimental setting suggest that the design with multiple check valves in paired configuration prevents retrograde contamination. Of note, this does not permit the reuse of propofol syringes because reusing is against the manufacturer's recommendations.

Routine use of nasogastric tubes does not reduce postoperative nausea and vomiting.

Routine use of a nasogastric (NG) tube has been suggested to prevent postoperative nausea and vomiting (PONV) despite conflicting data. Accordingly, we tested the hypothesis that routine use of a NG tube does not reduce PONV. Our work is based on data from a large trial of 4055 patients initially designed to quantify the effectiveness of combinations of antiemetic treatments for the prevention of PONV. This analysis uses propensity scores for case matching to ensure group comparability on baseline factors. Intraoperative NG tube use patients and perioperative NG tube use patients were respectively matched to nonuse patients on all available potential confounders. Matched-pairs were identified using propensity scores for 1032 patients with or without intraoperative NG tube use and 176 patients with or without perioperative NG tube use. The incidences of PONV in the intraoperative group were 44.4% vs 41.5% (P = 0.35) with and without tube use, respectively, and 27.8% vs 31.3% (P = 0.61) in the perioperative group. Our results provide evidence that routine use of a NG tube does not reduce the incidence of PONV.

The effect of postoperative fasting on vomiting in children and their assessment of pain.

BACKGROUND: Mandatory postoperative food intake has been shown to increase nausea and vomiting, and so postoperative fasting has become common practice even if patients request food or drink. OBJECTIVE: We sought to investigate whether postoperative fasting reduces the incidence of postoperative vomiting in children when compared with a liberal regimen in which they are allowed to eat and drink upon request. METHODS: One hundred forty-seven children scheduled for outpatient surgery were randomized to one of two groups. After anesthesia, patients in the 'fasting' group were expected to fast for 6 h. The children in the 'liberal' group were allowed to eat and drink according to their own needs. The incidence of vomiting and the children's well-being were recorded at several time points over a 24-hour period. Parents were also asked to rate, on a scale of 0-6, how much their children were bothered by fasting, pain, and nausea/vomiting. RESULTS: Age (4.8 +/- 2.6 years), weight (20 +/- 9 kg) and gender (73% boys) were comparable between the groups. The incidence of vomiting was 15% in the liberal and 22% in the fasting group (P = 0.39) and, between 1 and 12 h after extubation, children in the liberal group were significantly happier (P < 0.001). Children in the liberal group were significantly less bothered by their pain than those in the fasting group (P < 0.001). CONCLUSION: Postoperative fasting did not reduce the incidence of vomiting after general anesthesia in children when compared with a liberal regimen. Furthermore, the ability to eat and drink at will decrease the bothersome aspects of pain and lead to happier patients.

A simple clinical maneuver to reduce laparoscopy-induced shoulder pain: a randomized controlled trial.

OBJECTIVE: To estimate the efficacy of a simple clinical maneuver that facilitates removal of residual abdominal carbon dioxide (CO2) after laparoscopic surgery to reduce shoulder pain. METHODS: A total of 116 female outpatients who were scheduled for elective gynecologic laparoscopic surgery were randomly allocated to either the current standard (control group) or to additional efforts to remove residual CO2 at the end of surgery. In the control group, CO2 was removed by passive deflation of the abdominal cavity through the cannula. In the intervention group, CO2 was removed by means of Trendelenburg position (30 degrees) and a pulmonary recruitment maneuver consisting of five manual inflations of the lung. Postoperative shoulder pain was assessed before discharge and 12, 24, 36, and 48 hours later using a visual analog scale (VAS, 0-100). In addition, positional characteristics of the shoulder pain and incidence of postdischarge nausea and vomiting were recorded until 48 hours after discharge. RESULTS: Pain scores in the control and intervention groups were 30.3+/-4.5 compared with 15.6+/-3.0, 25.7+/-4.7 compared with 10.8+/-2.4, and 21.7+/-4.3 compared with 9.1+/-2.5 at 12, 24 and 36 hours after discharge, respectively (all P<.05). The intervention reduced positional pain from 63% to 31% (P<.05) and the incidence of postoperative nausea and vomiting from 56.5% to 20.4% (P<.001). CONCLUSION: This simple clinical maneuver at the end of surgery reduced shoulder pain as well as postoperative nausea and vomiting after laparoscopic surgery by more than half. CLINICAL TRIAL REGISTRATION: www.clinicaltrials.gov, ClinicalTrials.gov, NCT00575237 LEVEL OF EVIDENCE: I.