Norifumi Kuratani

Modified versus conventional ultrafiltration in pediatric cardiac surgery: a meta-analysis of randomized controlled trials comparing clinical outcome parameters.

OBJECTIVE Although previous studies have demonstrated that modified ultrafiltration improves laboratory parameters in pediatric cardiac surgery, the clinical outcome data have been inconsistent. We performed a meta-analysis of randomized controlled trials comparing modified versus conventional ultrafiltration. METHODS We conducted a comprehensive search of the literature to identify clinical trials that met our inclusion criteria. To be included, studies had to be prospective randomized trials that compared modified ultrafiltration and conventional ultrafiltration in pediatric cardiac surgery using cardiopulmonary bypass. We focused on the following outcome variables: hematocrit and mean arterial blood pressure after cardiopulmonary bypass, amount of chest tube drainage after surgery, time to extubation, and length of stay in the intensive care unit. The random effects model was used to determine the pooled effect estimates. The estimators of treatment effects were expressed as the weighted mean difference with 95% confidence intervals. The heterogeneity of collected data was also evaluated. RESULTS We screened 54 studies, 8 of which satisfied our inclusion criteria. Combined analysis revealed that modified ultrafiltration resulted in significantly higher postbypass hematocrit and higher mean arterial blood pressure. Benefits in postoperative blood loss, ventilator time, and intensive care unit stay were not apparent. There was significant heterogeneity among the studies surveyed. CONCLUSIONS The advantage of modified ultrafiltration over conventional ultrafiltration consists of significant improvement of clinical conditions in the immediate postbypass period. The postoperative outcome parameters were not significantly influenced. We should also take into account possible clinical or methodologic variations in the currently available ultrafiltration studies.

Incidence of postoperative shivering comparing remifentanil with other opioids: a meta-analysis

STUDY OBJECTIVE To determine whether the administration of remifentanil increases the incidence of postoperative shivering in comparison with the administration of alfentanil, fentanyl, or sufentanil. DESIGN Meta-analysis. SETTING Operating room and postanesthesia care unit. MEASUREMENTS We performed a computerized search of articles on PubMed, MEDLINE, and Scopus. Meta-analysis was performed using Review Manager and the DerSimonian and Laird random-effects model. The pooled effect estimates for binary variables were calculated as relative risk (RR) values with 95% confidence intervals (CIs). MAIN RESULTS Eighteen randomized controlled trials met our inclusion criteria. Remifentanil was associated with a significantly increased incidence of postoperative shivering compared with other opioids (RR=2.17; CI, 1.76-2.68; P<.00001; I(2)=0.00%). A subgroup analysis of remifentanil compared with alfentanil, fentanyl, or sufentanil showed that only sufentanil had a similar rate of postoperative shivering incidence (RR=2.13; CI, 0.67-6.74; P=.20; I(2)=0.00%). Remifentanil administration was associated with a significant increase in the incidence of postoperative shivering compared with the administration of other opioids when both propofol (RR=2.44; CI, 1.52-3.92; P=.0002; I(2)=0.00%) and inhalation anesthesia drugs (RR=2.45; CI, 1.46-4.11; P=.0007; I(2)=0.00%) were used for anesthesia maintenance. In addition, the administration of remifentanil at both low (RR=2.06; CI, 1.63-2.60; P<.00001; I(2)=0.00%) and high dosages (RR=2.77; CI, 1.67-4.57; P<.0001; I(2)=0.00%) was associated with a significant increase in the incidence of postoperative shivering compared with the administration of other opioids. CONCLUSIONS Our meta-analysis showed that remifentanil was associated with an increased incidence of postoperative shivering compared with alfentanil or fentanyl, but no significant difference was seen when compared with sufentanil.

Weekend versus weekday admission and short-term mortality: A meta-analysis of 88 cohort studies including 56,934,649 participants

Abstract It is widely accepted that higher mortality related to weekend admissions basically exists; however, there has been no systematic exploration of whether weekend admissions are associated with higher risk of death in patients on the basis of certain diagnoses, geographic regions, and study subtypes. A meta-analysis was performed according to the reporting guidelines of the Meta-analysis of Observational Studies in Epidemiology (MOOSE Compliant). Literature search was conducted using electronic databases. Primary outcome was short-term (⩽30-day) mortality. Patients were divided into 7 regions (North America, South America, Europe, Asia, Oceania, Africa, and Antarctica) for subgroup analyses and into 7 categories evaluating 24 major diagnoses. Pooled odds ratio (OR) with 95% confidence interval (CI) was calculated with DerSimonian and Laird random-effects models. Eighty-eight studies including 56,934,649 participants met our inclusion criteria. Overall pooled adjusted and crude OR of weekend to weekday admission for short-term mortality was 1.12 (95% CI, 1.07–1.18; I2 = 97%) and 1.16 (95% CI, 1.14–1.19; I2 = 97%), respectively. In subgroup analyses, higher risk of death on the weekend was significantly identified in patients living in all five continents (North America, South America, Europe, Asia, and Oceania). However, significant weekend effect was identified only in 15 of 24 diagnostic groups. Patients admitted on the weekend were more likely to die in an emergency situation (crude OR = 1.17, 95% CI, 1.12–1.22). Although weekend admissions were associated with higher risk of death compared with weekday admissions on all five continents, the effect was limited to certain diagnostic groups and admission subtypes. Weekend effect remains highly heterogeneous and limited, suggesting that further well-conducted cohort studies might be informative.

Immediate alleviation of chronic pain by bone drilling and probable involvement of bone tissue in pain sensitisation

Three patients presented with severe spontaneous pain, allodynia and numbness on the lateral side of the left heal, foot and/or toe due to L5 and/or S1 root injury, as a result of repeated failed back surgeries including Love’s surgery and laminaectomy (failed back surgery syndrome). The neuropathic pain in the lower extremities did not respond to somatic nerve block, lumbar-sympathetic ganglion block, spinal cord stimulation, and/or medications. At the spots in the foot showing the most severe allodynia, bones were drilled with fluoroscopic assistance. Spontaneous pain diminished immediately and allodynia was completely resolved. Visual analogue scale score decreased immediately after bone drilling. The analgesic effect was maintained for 30–45 weeks. In three patients, drilling until the marrow cavity of the bones at painful sites effectively relieved chronic neuropathic pain with lasting analgesic effect.

The cutting edge of neonatal anesthesia: the tide of history is changing

As reviewed by Drs. Yu and Liu in the previous issue of Journal of Anesthesia [1], focus on the safety of neonatal anesthesia has been from the aspect of long-term neurobehavioral outcomes. Neonatal anesthesia can be challenging even for experienced pediatric anesthesiologists if the baby was born prematurely or had co-morbidities. Epidemiological data suggest that the incidence of lifethreatening critical events in the perioperative period is consistently higher in the neonatal population. Their small body size and the prematurity of vital organ systems cause the safety margin to be small in perioperative management. The anesthesia equipment may not be exclusively designed for small babies, and not all anesthesiologists have appropriate training and experience in neonatal anesthesia. Some modern monitoring systems are not applicable for the neonate, and basic vital signs are still the mainstay of patient monitoring. Information regarding the rational use of anesthesia-related medication for the neonatal population is often sparse. In addition, there seems to be substantial individual pharmacokinetic and pharmacodynamic variability among neonatal patients. Clinical trials exploring better management are often difficult for a number of practical and ethical reasons. Thus, although the progress of neonatal anesthesia has been somewhat slow, we are currently witnessing a landmark event in the history of neonatal anesthesia. Until the 1980s, the ‘‘Liverpool technique’’ had been the common anesthesia method for neonates. The Liverpool technique for neonatal anesthesia consists fundamentally of light general anesthesia and a muscle relaxant, typically with nitrous oxide and with D-tubocurarine (curare). At that time, neonates were believed not to feel pain because of their immature sensory nervous system. Pain treatment for neonates was considered to be unnecessary or even contraindicated. By reason of their immature cardiovascular and respiratory systems, neonates were assumed to be too sensitive to the depressant effects of anesthetics. However, in the 1980s, with the development of neurophysiological research in the neonatal population, accumulating evidence showed that neonates do feel pain and consistently respond to noxious stimuli. A seminal study by Anand et al. in 1987 [2] showed that withholding opioids in invasive neonatal surgery results in an exaggerated stress response and adversely affects the surgical outcome. Since then, anesthesiologists have been aware that analgesia is an essential component of neonatal anesthesia. However, clinical application of analgesia for neonatal surgery has been inconsistent among practitioners, even though there has been a growing body of evidence supporting the importance of analgesia during surgery. Analgesia using regional anesthesia is not always feasible for small patients, and the use of opioids, including fentanyl or morphine, was generally limited to patients who were originally planned to be on the ventilator. As a result, hypnotic-based anesthesia, such as sevoflurane, has been a popular approach to anesthetize neonatal patients. In recent years, we have been facing newly emerging problems concerning the neurotoxic effects of anesthetics on the developing brain. More than 50 animal studies indicate that varieties of anesthetics, including volatile anesthetics, thiopental, propofol, benzodiazepines, and ketamine, cause neuronal apoptosis under specific conditions. Some animal studies clearly demonstrated longterm neurobehavioral impairment following neonatal exposure to anesthetics. Although experimental evidence N. Kuratani (&) Department of Anesthesia, Saitama Children’s Medical Center, 2100 Magome, Iwatsuki, Saitama-City, Saitama 339-8551, Japan e-mail: nori-kuratani@umin.ac.jp

The role of Journal of Anesthesia as a flagship anesthesia journal in Asia

Japanese practice and research are presented [2]. Prof. Amaha, the founding editor-in-chief of JA, intended that Japanese techniques, clinical problems, and ongoing research would become available to anesthesiologists throughout the world, fostering a greater exchange of ideas [2]. Thirty years after the first volume of JA was released, it is clear that JA’s original purpose has been achieved with great success. JA is indexed in several medical search engines, including PubMed and Scopus, and is circulated in the anesthesia community all over the globe. JA has served as a catalyst to inspire further development in our field and has brought great benefits to every aspect of anesthesiology in Japan [2]. The rest of Asia, meanwhile, is a mixed region in terms of socioeconomic development. Whereas China and Korea are increasing their presence in anesthesia research [3, 4], many anesthesia societies in LLMICs still have a low scholarly output. Anesthesiologists in these LLMICs would likely find it difficult to launch and maintain an international journal comparable to JA that would meet the global standards of medical research due to the shortage of funds and the lack of clear individual-level benefits resulting from such an undertaking. As a result, the majority of research findings from LLMICs are not indexed in major medical databases and might in fact be inaccessible to the rest of the world. JA plays a role in counteracting this tendency by publishing substantial quantities of academic output from other Asian countries. In 2016, JA published 85 original articles, of which 29 were from Asian countries other than Japan (Fig. 1). The Asian articles distributed by JA made a substantial impact on the progress of anesthesia research. For example, that by Zhang et al., from China, reported the results of a meta-analysis regarding an association between childhood exposure to single general anesthesia and later neurodevelopmental outcome [5]. The authors summarized the currently available evidence regarding anesthesia To the Editor:

Efficacy of prophylactic doses of intravenous nitroglycerin in preventing myocardial ischemia under general anesthesia: A systematic review and meta-analysis with trial sequential analysis

STUDY OBJECTIVE To evaluate the efficacy of intravenous nitroglycerin (TNG) in preventing intraoperative myocardial ischemia (MI) under general anesthesia. Moreover, we analyzed the hemodynamic changes in heart rate (HR), mean blood pressure (MBP), and pulmonary capillary wedge pressure (PCWP) associated with TNG administration both before and after the induction of anesthesia. DESIGN Meta-analysis. SETTING Operating room, cardiac surgery or non-cardiac surgery, all surgeries were elective measurements. We performed a computerized search of articles on PubMed, Scopus, and the Cochrane Central Register of Controlled Trials. Meta-analysis was performed using Review Manager. The data from the individual trials were combined using a random-effects model to calculate either the pooled relative risk (RR) or the weighted mean difference (WMD) with 95% confidence interval (CI). We conducted trial sequential analysis (TSA). The primary outcome was the incidence of MI and the secondary outcomes were hemodynamic changes (HR, MBP, and PCWP). MAIN RESULTS Using electronic databases, we selected 10 trials with a total of 353 patients for our review. Prophylactic intravenous TNG did not significantly decrease the incidence of MI (RR=0.61; CI, 0.33 to 1.13; P=0.12; I2=55). TSA corrected the CI to 0.05 to 7.39 and showed that 9.5% of the required information size was achieved. In terms of hemodynamic changes, intravenous TNG significantly reduced MBP in comparison with the placebo (MBP pre-induction: WMD=-7.27; 95% CI -14.2 to -0.33; P=0.04; I2=97%; MBP post-induction: WMD=-5.13; 95% CI -9.17 to -1.09; P=0.01; I2=73%). CONCLUSIONS Our analyses showed that prophylactic intravenous TNG does not reduce the incidence of intraoperative MI. Moreover, TSA suggests that further studies are necessary to confirm the results (GRADE: very low). Prophylactic doses of intravenous TNG significantly reduced the MBP both pre and post anesthesia induction (GRADE: very low).

Pediatric anesthesia: current status and future directions

however, emphasized that, even when the new ETT is used, close attention must be paid to maintaining cuff pressure within the appropriate range to avoiding postoperative airway complications. In particular, it has been shown that cuff pressure is not always stable throughout anesthesia. As cuff pressure is affected by various factors, including patient positioning, continuous monitoring and adjustment of cuff pressure are strongly advocated [1]. Dr. Soichiro Obara of Saitama Children’s Medical Center, Japan, covered issues related to adverse events associated with the management of the pediatric airway outside the operating room (OR), especially in the pediatric emergency department and the pediatric intensive care unit and during sedation of infants and children, including the ramifications of the latest literature. The question of which strategies are most effective at helping non-anesthesia trainees to achieve proficiency in pediatric airway management is the central issue here. He presented the possible solutions, including simulation training and the formation of a formal multidisciplinary team of airway specialists known as the Difficult Airway Service [2], and noted that both of these solutions would be most effective if directed by anesthesiologists. Although it remains somewhat unclear whether the involvement of anesthesiologists contributes to safety in the management of the pediatric airway outside the OR, Dr. Obara stressed the importance of anesthesiologists’ efforts to reach out and get involved in the issue through close coordination and collaboration with other departments. Dr. Yuji Kitamura of the Montréal Children’s Hospital, Montréal, Canada, discussed perioperative anesthetic management in tonsillectomy and adenoidectomy (T&A) for children with severe obstructive sleep apnea (OSA). In North America, where T&A is often conducted on an ambulatory basis, out-of-hospital deaths in the early days As part of the 62nd Annual Meeting of the Japanese Society of Anesthesiologists, the 10th Journal of Anesthesia (JA) Symposium was held on May 28, 2015 in Kobe, Japan. The JA Symposium has been convened annually since 2006. The goals of the symposium are to facilitate cutting-edge discussion at the forefront of anesthesiology and to promote JA among the anesthesia community around the world. This year’s JA symposium focused on pediatric anesthesia, and the title of the symposium was “Pediatric Anesthesia: Current Status and Future Directions.” Five distinguished speakers gathered to discuss their respective areas of expertise. Two moderators, Dr. Kanmura and Dr. Kuratani, facilitated the discussions. The first speaker, Dr. Hiromi Kako of Nationwide Children’s Hospital, Columbus, OH, USA, discussed topics related to the use of the cuffed endotracheal tube (ETT) in the pediatric population. The use of the cuffed ETT in small children and infants has been a controversial issue in the pediatric anesthesia community. The advantages of the cuffed ETT are obvious, yet safety concerns associated with it are yet to be completely addressed. Newly invented cuffed ETTs with thin polyurethane microcuffs are said to overcome some of the disadvantages related to cuff design in the previously available polyvinyl chloride (PVC) cuffs, and the new generation of cuffed ETTs may be a game changer in pediatric airway management. Dr. Kako,