Ivo F. Brandes

A Multicenter Trial of Remote Ischemic Preconditioning for Heart Surgery

BACKGROUND Remote ischemic preconditioning (RIPC) is reported to reduce biomarkers of ischemic and reperfusion injury in patients undergoing cardiac surgery, but uncertainty about clinical outcomes remains. METHODS We conducted a prospective, double-blind, multicenter, randomized, controlled trial involving adults who were scheduled for elective cardiac surgery requiring cardiopulmonary bypass under total anesthesia with intravenous propofol. The trial compared upper-limb RIPC with a sham intervention. The primary end point was a composite of death, myocardial infarction, stroke, or acute renal failure up to the time of hospital discharge. Secondary end points included the occurrence of any individual component of the primary end point by day 90. RESULTS A total of 1403 patients underwent randomization. The full analysis set comprised 1385 patients (692 in the RIPC group and 693 in the sham-RIPC group). There was no significant between-group difference in the rate of the composite primary end point (99 patients [14.3%] in the RIPC group and 101 [14.6%] in the sham-RIPC group, P=0.89) or of any of the individual components: death (9 patients [1.3%] and 4 [0.6%], respectively; P=0.21), myocardial infarction (47 [6.8%] and 63 [9.1%], P=0.12), stroke (14 [2.0%] and 15 [2.2%], P=0.79), and acute renal failure (42 [6.1%] and 35 [5.1%], P=0.45). The results were similar in the per-protocol analysis. No treatment effect was found in any subgroup analysis. No significant differences between the RIPC group and the sham-RIPC group were seen in the level of troponin release, the duration of mechanical ventilation, the length of stay in the intensive care unit or the hospital, new onset of atrial fibrillation, and the incidence of postoperative delirium. No RIPC-related adverse events were observed. CONCLUSIONS Upper-limb RIPC performed while patients were under propofol-induced anesthesia did not show a relevant benefit among patients undergoing elective cardiac surgery. (Funded by the German Research Foundation; RIPHeart ClinicalTrials.gov number, NCT01067703.).

Intensified thermal management for patients undergoing transcatheter aortic valve implantation (TAVI)

BackgroundTranscatheter aortic valve implantation via the transapical approach (TAVI-TA) without cardiopulmonary bypass (CPB) is a minimally invasive alternative to open-heart valve replacement. Despite minimal exposure and extensive draping perioperative hypothermia still remains a problem.MethodsIn this observational study, we compared the effects of two methods of thermal management on the perioperative course of core temperature. The methods were standard thermal management (STM) with a circulating hot water blanket under the patient, forced-air warming with a lower body blanket and warmed infused fluids, and an intensified thermal management (ITM) with additional prewarming using forced-air in the pre-operative holding area on the awake patient.ResultsNineteen patients received STM and 20 were treated with ITM. On ICU admission, ITM-patients had a higher core temperature (36.4 ± 0.7°C vs. 35.5 ± 0.9°C, p = 0.001), required less time to achieve normothermia (median (IQR) in min: 0 (0-15) vs. 150 (0-300), p = 0.003) and a shorter period of ventilatory support (median (IQR) in min: 0 (0-0) vs. 246 (0-451), p = 0.001).ConclusionITM during TAVI-TA reduces the incidence of hypothermia and allows for faster recovery with less need of ventilatory support.

[Prewarming. Yesterday's luxury, today's minimum requirement].

Prewarming is a useful and effective measure to reduce perioperative hypothermia. Due to §23(3) of the German Infektionsschutzgesetz (Gesetz zur Verhütung und Bekämpfung von Infektionskrankheiten beim Menschen, Infection Act, act on protection and prevention of infectious diseases in man) and the recommendations of the Hospital Hygiene and Infection Prevention Committee of the Robert Koch Institute, implementation of prewarming is clearly recommended. There are several technically satisfactory and practicable devices available allowing prewarming on the normal hospital ward, in the preoperative holding area or in the induction room of the operating theater (OR) The implementation of prewarming requires additional equipment and training of staff. Using a locally adapted concept for the implementation of prewarming does not lead to inefficiency in the perioperative process. In contrast, the implementation can help to achieve stable arrival times for patients in the OR.

Effektivität einer neuen Wärmedecke

BACKGROUND Perioperative hypothermia is a common complication of general anesthesia and occurs in up to 50 % of patients during ear, nose and throat (ENT) surgery. In this prospective, randomized controlled study the hypothesis that a new conductive warming blanket (Barrier® EasyWarm®, Mölnlycke Health Care Erkrath, Germany) is better in reducing the incidence of perioperative hypothermia in ENT surgery than insulation with a conventional hospital duvet alone was tested. MATERIALS AND METHODS After approval of the local ethics committee and written informed consent 80 patients with a planned procedure time between 1 and 3 h were recruited. Anesthesia was induced and maintained using propofol, remifentanil and rocuronium and the core temperature was measured using an esophageal temperature probe. Patients in the study group were warmed at least 30 min prior to induction of anesthesia using the novel warming blanket (Barrier® EasyWarm®) and patients in the control group were insulated with a standard hospital duvet. Data were tested using Fishers exact test, Students t-test or the Mann-Whitney U-test as appropriate. Time-dependent changes in core temperature were evaluated using repeated measures analysis of variance (ANOVA) and post hoc Scheffés test. Results are expressed as mean ± SD or as median and interquartile range (IQR) as appropriate. A p < 0.05 was considered to be statistically significant. RESULTS The ANOVA did not identify a significantly higher core temperature in the study group at any time point. Furthermore, Fishers exact test showed no differences in the incidence of intraoperative (12 out of 29 versus 10 out of 32 patients, p = 0.44) or postoperative hypothermia (12 out of 29 versus 9 out of 32 patients, p = 0.30) between the groups. No adverse effects were observed. CONCLUSIONS In the studied patient group the new conductive warming blanket (Barrier® EasyWarm®) showed no superiority compared to conventional thermal insulation alone.

Evaluation of a novel noninvasive continuous core temperature measurement system with a zero heat flux sensor using a manikin of the human body

Abstract Reliable continuous perioperative core temperature measurement is of major importance. The pulmonary artery catheter is currently the gold standard for measuring core temperature but is invasive and expensive. Using a manikin, we evaluated the new, noninvasive SpotOn™ temperature monitoring system (SOT). With a sensor placed on the lateral forehead, SOT uses zero heat flux technology to noninvasively measure core temperature; and because the forehead is devoid of thermoregulatory arteriovenous shunts, a piece of bone cement served as a model of the frontal bone in this study. Bias, limits of agreements, long-term measurement stability, and the lowest measurable temperature of the device were investigated. Bias and limits of agreement of the temperature data of two SOTs and of the thermistor placed on the manikin’s surface were calculated. Measurements obtained from SOTs were similar to thermistor values. The bias and limits of agreement lay within a predefined clinically acceptable range. Repeat measurements differed only slightly, and stayed stable for hours. Because of its temperature range, the SOT cannot be used to monitor temperatures below 28°C. In conclusion, the new SOT could provide a reliable, less invasive and cheaper alternative for measuring perioperative core temperature in routine clinical practice. Further clinical trials are needed to evaluate these results.

Unexpectedly high incidence of hypothermia before induction of anesthesia in elective surgical patients

STUDY OBJECTIVE Perioperative hypothermia is a frequently observed phenomenon of general anesthesia and is associated with adverse patient outcome. Recently, a significant influence of core temperature before induction of anesthesia has been reported. However, there are still little existing data on core temperature before induction of anesthesia and no data regarding potential risk factors for developing preoperative hypothermia. The purpose of this investigation was to estimate the incidence of hypothermia before anesthesia and to determine if certain factors predict its incidence. DESIGN/SETTING/PATIENTS Data from 7 prospective studies investigating core temperature previously initiated at our department were analyzed. Patients undergoing a variety of elective surgical procedures were included. INTERVENTIONS/MEASUREMENTS Core temperature was measured before induction of anesthesia with an oral (314 patients), infrared tympanic (143 patients), or tympanic contact thermometer (36 patients). Available potential predictors included American Society of Anesthesiologists status, sex, age, weight, height, body mass index, adipose ratio, and lean body weight. Association with preoperative hypothermia was assessed separately for each predictor using logistic regression. Independent predictors were identified using multivariable logistic regression. MAIN RESULTS A total of 493 patients were included in the study. Hypothermia was found in 105 patients (21.3%; 95% confidence interval, 17.8%-25.2%). The median core temperature was 36.3°C (25th-75th percentiles, 36.0°C-36.7°C). Two independent factors for preoperative hypothermia were identified: male sex and age (>52years). CONCLUSIONS As a consequence of the high incidence of hypothermia before anesthesia, measuring core temperature should be mandatory 60 to 120minutes before induction to identify and provide adequate treatment to hypothermic patients.

[Efficacy of a novel warming blanket: prospective randomized trial].

BACKGROUND Perioperative hypothermia is a common complication of general anesthesia and occurs in up to 50 % of patients during ear, nose and throat (ENT) surgery. In this prospective, randomized controlled study the hypothesis that a new conductive warming blanket (Barrier® EasyWarm®, Mölnlycke Health Care Erkrath, Germany) is better in reducing the incidence of perioperative hypothermia in ENT surgery than insulation with a conventional hospital duvet alone was tested. MATERIALS AND METHODS After approval of the local ethics committee and written informed consent 80 patients with a planned procedure time between 1 and 3 h were recruited. Anesthesia was induced and maintained using propofol, remifentanil and rocuronium and the core temperature was measured using an esophageal temperature probe. Patients in the study group were warmed at least 30 min prior to induction of anesthesia using the novel warming blanket (Barrier® EasyWarm®) and patients in the control group were insulated with a standard hospital duvet. Data were tested using Fishers exact test, Students t-test or the Mann-Whitney U-test as appropriate. Time-dependent changes in core temperature were evaluated using repeated measures analysis of variance (ANOVA) and post hoc Scheffés test. Results are expressed as mean ± SD or as median and interquartile range (IQR) as appropriate. A p < 0.05 was considered to be statistically significant. RESULTS The ANOVA did not identify a significantly higher core temperature in the study group at any time point. Furthermore, Fishers exact test showed no differences in the incidence of intraoperative (12 out of 29 versus 10 out of 32 patients, p = 0.44) or postoperative hypothermia (12 out of 29 versus 9 out of 32 patients, p = 0.30) between the groups. No adverse effects were observed. CONCLUSIONS In the studied patient group the new conductive warming blanket (Barrier® EasyWarm®) showed no superiority compared to conventional thermal insulation alone.

Feasibility of implantable cardioverter defibrillator treatment in five patients with familial Friedreich's ataxia--a case series.

Friedreichs ataxia (FRA) is an autosomal recessive disease of the central nervous system that is associated with familial cardiomyopathy. Cardiac involvement is seen in more than 90% of the patients and is the most common cause of death in these patients. We present a case series and discuss the indications for implantable cardioverter defibrillator (ICD) implantation in FRA with review of the literature. Five pediatric patients who suffer from FRA (four female and one male, mean age 17.4 years) underwent ICD implantation between 2007 and 2008 in the University Hospital of Goettingen. The diagnosis of FRA was established by standard clinical criteria and proven in each case by genotyping at the frataxin locus. The time from diagnosis to ICD implantation was 10.4±1.73 years (range 8-15 years). All patients received transvenous lead systems. There were no intraoperative and postoperative complications. At the latest follow-up, the neuromuscular symptoms exhibited no further progress and no ICD activations were noticed. Only minor repolarization changes were seen on electrocardiogram. All patients had normal echocardiographic findings and no angina has been reported. Coronary angiographies were normal. It is evident that many FRA patients develop ventricular dysfunction. In the absence of a definitive surgical cure an ICD is generally indicated in young patients with hemodynamically significant sustained ventricular tachyarrhythmias for prevention of sudden cardiac death. Our experience implies the safe use of ICD in children with FRA.

Comparison of Conductive and Convective Warming in Patients Undergoing Video-Assisted Thoracic Surgery: A Prospective Randomized Clinical Trial.

Background Perioperative hypothermia is frequent during thoracic surgery. After approval by the local ethics committee and written informed consent from patients, we examined the efficiency of prewarming and intraoperative warming with a convective warming system and conductive warming system to prevent perioperative hypothermia during video‐assisted thoracic surgery (VATS). Methods We randomized 60 patients with indication for VATS in two groups (convective warming with an underbody blanket vs. conductive warming with an underbody mattress and additional warming of the legs). All patients were prewarmed before induction of anesthesia with the corresponding system. Core temperature was measured sublingual and in the nasopharynx. Results Both groups were not significantly different in regard to clinical parameter, prewarming, and initial core temperature. The patients in conduction group had lower intraoperative core temperatures and a higher incidence of intraoperative (73.9 vs. 24%) and postoperative hypothermia (56.5 vs. 8%) compared with convective warming. Conclusions Pre‐ and intraoperative convective warming with an underbody blanket prevents perioperative hypothermia during VATS better than conductive warming. The inferior prevention in conductive warming group may be caused by reduced body contact to the warming mattresses in lateral position.

Vor- und Nachteile verschiedener Techniken zur Bereitstellung und Pflege von Standard Operating Procedures

BACKGROUND The quality assurance of care and patient safety, with increasing cost pressure and performance levels is of major importance in the high-risk and high cost area of the operating room (OR). Standard operating procedures (SOP) are an established tool for structuring and standardization of the clinical treatment pathways and show multiple benefits for quality assurance and process optimization. OBJECTIVES An internal project was initiated in the department of anesthesiology and a continuous improvement process was carried out to build up a comprehensive SOP library. MATERIAL AND METHODS In the first step the spectrum of procedures in anesthesiology was transferred to PDF-based SOPs. The further development to an app-based SOP library (Aesculapp) was due to the high resource expenditure for the administration and maintenance of the large PDF-based SOP collection and to deficits in the mobile availability. The next developmental stage, the SOP healthcare information assistant (SOPHIA) included a simplified and advanced update feature, an archive feature previously missing and notably the possibility to share the SOP library with other departments including the option to adapt each SOP to the individual situation. A survey of the personnel showed that the app-based allocation of SOPs (Aesculapp, SOPHIA) had a higher acceptance than the PDF-based developmental stage SOP form. CONCLUSION The SOP management system SOPHIA combines the benefits of the forerunner version Aesculapp with improved options for intradepartmental maintenance and administration of the SOPs and the possibility of an export and editing function for interinstitutional exchange of SOPs.ZusammenfassungHintergrundDie Sicherung von Versorgungsqualität und Patientensicherheit hat bei zunehmendem Kostendruck und Leistungsverdichtung eine besondere Bedeutung im Hochrisiko- und Hochkostenbereich OP. Zur Strukturierung und zur Standardisierung der Versorgungspfade haben sich Standard Operating Procedures (SOP) etabliert und zeigen einen vielfältigen Nutzen bei der Qualitätssicherung und Prozessoptimierung.Ziel der ArbeitZum Aufbau einer umfassenden SOP-Sammlung in der Anästhesiologie wurde ein abteilungsinternes Projekt initiiert und im Sinne eines kontinuierlichen Verbesserungsprozesses durchgeführt.Material und MethodenIm ersten Schritt wurde das Leistungsspektrum der Klinik über PDF-basierte SOP abgebildet. Aufgrund des hohen Ressourcenaufwands bei der Verwaltung und Pflege dieser umfangreichen SOP-Bibliothek sowie Defiziten in der mobilen Verfügbarkeit erfolgte die Weiterentwicklung zu einer App-gestützten SOP-Sammlung (Aesculapp). In der folgenden Entwicklungsstufe, dem SOP Healthcare Information Assistent (SOPHIA), wurde die Aktualisierungsfunktion weiter vereinfacht, eine bislang fehlende Archivierungsfunktion eingeführt und insbesondere die Möglichkeit geschaffen, die SOP-Sammlung anderen Abteilungen über einen Bearbeitungsmodus adaptierbar zur Verfügung zu stellen.Eine Mitarbeiterbefragung zeigte, dass die App-gestützte Bereitstellung von SOP (Aesculapp, SOPHIA) eine höhere Akzeptanz als die PDF-basierte SOP-Entwicklungsstufe aufwies.SchlussfolgerungDas SOP-Management-System SOPHIA kombiniert die Vorteile der Vorversion Aesculapp mit verbesserten Möglichkeiten in der abteilungsinternen Pflege und Verwaltung der SOP sowie der Option einer Export- und Editierfunktion zum einrichtungsübergreifenden SOP-Austausch.AbstractBackgroundThe quality assurance of care and patient safety, with increasing cost pressure and performance levels is of major importance in the high-risk and high cost area of the operating room (OR). Standard operating procedures (SOP) are an established tool for structuring and standardization of the clinical treatment pathways and show multiple benefits for quality assurance and process optimization.ObjectivesAn internal project was initiated in the department of anesthesiology and a continuous improvement process was carried out to build up a comprehensive SOP library.Material and methodsIn the first step the spectrum of procedures in anesthesiology was transferred to PDF-based SOPs. The further development to an app-based SOP library (Aesculapp) was due to the high resource expenditure for the administration and maintenance of the large PDF-based SOP collection and to deficits in the mobile availability. The next developmental stage, the SOP healthcare information assistant (SOPHIA) included a simplified and advanced update feature, an archive feature previously missing and notably the possibility to share the SOP library with other departments including the option to adapt each SOP to the individual situation.A survey of the personnel showed that the app-based allocation of SOPs (Aesculapp, SOPHIA) had a higher acceptance than the PDF-based developmental stage SOP form.ConclusionThe SOP management system SOPHIA combines the benefits of the forerunner version Aesculapp with improved options for intradepartmental maintenance and administration of the SOPs and the possibility of an export and editing function for interinstitutional exchange of SOPs.