Anesthesiology Research and Practice The latest articles from Hindawi Publishing Corporation © 2015 , Hindawi Publishing Corporation . All rights reserved. Postoperative Residual Neuromuscular Paralysis at an Australian Tertiary Children’s Hospital Sun, 10 May 2015 07:03:00 +0000 Purpose. Residual neuromuscular blockade (RNMB) is known to be a significant but frequently overlooked complication after the use of neuromuscular blocking agents (NMBA). Aim of this prospective audit was to investigate the incidence and severity of RNMB at our Australian tertiary pediatric center. Methods. All children receiving NMBA during anesthesia were included over a 5-week period at the end of 2011 (Mondays to Fridays; 8 a.m.–6 p.m.). At the end of surgery, directly prior to tracheal extubation, the train-of-four (TOF) ratio was assessed quantitatively. Data related to patient postoperative outcome was collected in the postoperative acute care unit. Results. Data of 64 patients were analyzed. Neostigmine was given in 34 cases and sugammadex in 1 patient. The incidence of RNMB was 28.1% overall (without reversal: 19.4%; after neostigmine: 37.5%; n.s.). Severe RNMB (TOF ratio < 0.7) was found in 6.5% after both no reversal and neostigmine, respectively. Complications in the postoperative acute care unit were infrequent, with no differences between reversal and no reversal groups. Conclusions. In this audit, RNMB was frequently observed, particularly in cases where patients were reversed with neostigmine. These findings underline the well-known problems associated with the use of NMBA that are not fully reversed. Thomas Ledowski, Brendan O’Dea, Luke Meyerkort, Mary Hegarty, and Britta S. von Ungern-Sternberg Copyright © 2015 Thomas Ledowski et al. All rights reserved. Survey of Accepted Practice following Failed Intubation for Emergency Caesarean Delivery Tue, 03 Mar 2015 06:38:02 +0000 Background. There is no consensus on the optimum management of failed tracheal intubation in emergency cesarean delivery performed for fetal compromise. The decision making process on whether to wake the patient or continue anesthesia with a supraglottic airway device is an underexplored area. This survey explores perceptions and experiences of obstetric anesthetists managing failed intubation. Methods. Anesthetists attending the Group of Obstetric Anaesthetists London (GOAL) Meeting in April 2014 were surveyed. Results. Ninety-three percent of anesthetists surveyed would not always wake the patient in the event of failed intubation for emergency cesarean delivery performed for fetal compromise. The median (interquartile range) of perceived acceptability of continuing anesthesia with a well-fitting supraglottic airway device, assessed using a visual analogue scale (0–100; 0 completely unacceptable; 100 completely acceptable), was 90 [22.5]. Preoperative patient consent regarding the use of a supraglottic airway device for surgery in the event of failed intubation would affect the decision making of 40% of anaesthetists surveyed. Conclusion. These results demonstrate that a significant body of anesthetists with a subspecialty interest in obstetric anesthesia in the UK would not always wake up the patient and would continue with anesthesia and surgery with a supraglottic airway device in this setting. Daniel Soltanifar, David Bogod, Sally Harrison, Brendan Carvalho, and Pervez Sultan Copyright © 2015 Daniel Soltanifar et al. All rights reserved. Effect of Low-Dose (Single-Dose) Magnesium Sulfate on Postoperative Analgesia in Hysterectomy Patients Receiving Balanced General Anesthesia Sun, 01 Feb 2015 14:29:26 +0000 Background and Aim. Aparallel, randomized, double blinded, placebo-controlled trial study was designed to assess the efficacy of single low dose of intravenous magnesium sulfate on post-total abdominal hysterectomy (TAH) pain relief under balanced general anesthesia. Subject and Methods. Forty women undergoing TAH surgery were assigned to two magnesium sulfate () and normal saline () groups randomly. The magnesium group received magnesium sulfate 50 mgkg−1 in 100 mL of normal saline solution i.v as single-dose, just 15 minutes before induction of anesthesia whereas patients in control group received 100 mL of 0.9% sodium chloride solution at the same time. The same balanced general anesthesia was induced for two groups. Pethidine consumption was recorded over 24 hours precisely as postoperative analgesic. Pain score was evaluated with Numeric Rating Scale (NRS) at 0, 6, 12, and 24 hours after the surgeries. Results. Postoperative pain score was lower in magnesium group at 6, 12, and 24 hours after the operations significantly (). Pethidine requirement was significantly lower in magnesium group throughout 24 hours after the surgeries (). Conclusion. Single dose of magnesium sulfate during balanced general anesthesia could be considered as effective and safe method to reduce postoperative pain and opioid consumption after TAH. Arman Taheri, Katayoun Haryalchi, Mandana Mansour Ghanaie, and Neda Habibi Arejan Copyright © 2015 Arman Taheri et al. All rights reserved. Potential Risk Factors for the Onset of Complex Regional Pain Syndrome Type 1: A Systematic Literature Review Mon, 26 Jan 2015 07:21:15 +0000 Anaesthetists in the acute and chronic pain teams are often involved in treating Complex Regional Pain Syndromes. Current literature about the risk factors for the onset of Complex Regional Pain Syndrome Type 1 (CRPS 1) remains sparse. This syndrome has a low prevalence, a highly variable presentation, and no gold standard for diagnosis. In the research setting, the pathogenesis of the syndrome continues to be elusive. There is a growing body of literature that addresses efficacy of a wide range of interventions as well as the likely mechanisms that contribute to the onset of CRPS 1. The objective for this systematic search of the literature focuses on determining the potential risk factors for the onset of CRPS 1. Eligible articles were analysed, dated 1996 to April 2014, and potential risk factors for the onset of CRPS 1 were identified from 10 prospective and 6 retrospective studies. Potential risk factors for the onset of CRPS 1 were found to include being female, particularly postmenopausal female, ankle dislocation or intra-articular fracture, immobilisation, and a report of higher than usual levels of pain in the early phases of trauma. It is not possible to draw definite conclusions as this evidence is heterogeneous and of mixed quality, relevance, and weighting strength against bias and has not been confirmed across multiple trials or in homogenous studies. Tracey Pons, Edward A. Shipton, Jonathan Williman, and Roger T. Mulder Copyright © 2015 Tracey Pons et al. All rights reserved. Neuromuscular Monitoring, Muscle Relaxant Use, and Reversal at a Tertiary Teaching Hospital 2.5 Years after Introduction of Sugammadex: Changes in Opinions and Clinical Practice Thu, 15 Jan 2015 08:30:41 +0000 Sugammadex was introduced to Royal Perth Hospital in early 2011 without access restriction. Two departmental audits (26-page online survey and 1-week in-theatre snapshot audit) were undertaken to investigate the change of beliefs and clinical practice related to the use of neuromuscular blocking agents at the Royal Perth Hospital since this introduction. Results were compared with data from 2011. We found that, in the 2.5 years since introduction of Sugammadex, more anesthetists (69.5 versus 38%) utilized neuromuscular monitoring, and aminosteroidal neuromuscular blocking agents were used in 94.3% of cases (versus 77% in 2011). Furthermore, 53% of anesthetists identified with a practice of “deeper and longer” intraoperative paralysis of patients. All 71 patients observed during the 5-day in-theatre audit were reversed with Sugammadex. Since the introduction of Sugammadex, 69% of respondents felt it provided “faster turnover,” less postoperative residual neuromuscular blockade ; 79%), and higher anesthetist satisfaction ; 59%). 45% of colleagues reported that they would feel professionally impaired without the unrestricted availability of Sugammadex, and 1 colleague would refuse to work in a hospital without this drug being freely available. In clinical practice Sugammadex was frequently (57%) mildly overdosed, with 200 mg being the most commonly administered dose. Thomas Ledowski, Jing Shen Ong, and Tom Flett Copyright © 2015 Thomas Ledowski et al. All rights reserved. The Impact of a Dedicated Research Education Month for Anesthesiology Residents Tue, 13 Jan 2015 06:49:32 +0000 An educational intervention was implemented at the University of Michigan starting in 2008, in which anesthesiology interns complete a dedicated month-long didactic rotation in evidence-based medicine (EBM) and research methodology. We sought to assess its utility. Scores on a validated EBM test before and after the rotation were compared and assessed for significance of improvement. A survey was also given to gauge satisfaction with the quality of the rotation and self-reported improvement in understanding of EBM topics. Fourteen consecutive interns completed the research rotation during the study period. One hundred percent completed both the pre- and postrotation test. The mean pretest score was 7.78 ± 2.46 (median = 7.5, 0–15 scale, and interquartile range 7.0–10.0) and the mean posttest score was 10.00 ± 2.35 (median = 9.5, interquartile range 8.0–12.3), which represented a statistically significant increase (, Wilcoxon signed-rank test). All fourteen of the residents “agreed” or “strongly agreed” that they would recommend the course to future interns and that the course increased their ability to critically review the literature. Our findings demonstrate that this can be an effective means of improving understanding of EBM topics and anesthesiology research. Robert E. Freundlich, Jessica W. Newman, Kevin K. Tremper, Jill M. Mhyre, Sachin Kheterpal, Theodore J. Sanford Jr., and Alan R. Tait Copyright © 2015 Robert E. Freundlich et al. All rights reserved. Influence of Head and Neck Position on Oropharyngeal Leak Pressure and Cuff Position with the ProSeal Laryngeal Mask Airway and the I-Gel: A Randomized Clinical Trial Sun, 11 Jan 2015 13:04:51 +0000 Background. This study was designed to assess and compare the effect of head and neck position on the oropharyngeal leak pressures and cuff position (employing fibreoptic view of the glottis) and ventilation scores between ProSeal LMA and the I-gel. Material and Methods. After induction of anesthesia, the supraglottic device was inserted and ventilation confirmed. The position of the head was randomly changed from neutral to flexion, extension, and lateral rotation (left). The oropharyngeal leak pressures, fibreoptic view of glottis, ventilation scores, and delivered tidal volumes and end tidal CO2 were noted in all positions. Results. In both groups compared with neutral position, oropharyngeal leak pressures were significantly higher with flexion and lower with extension but similar with rotation of head and neck. However the oropharyngeal leak pressure was significantly higher for ProSeal LMA compared with the I-gel in all positions. Peak airway pressures were significantly higher with flexion in both groups (however this did not affect ventilation), lower with extension in ProSeal group, and comparable in I-gel group but did not change significantly with rotation of head and neck in both groups. Conclusion. Effective ventilation can be done with both ProSeal LMA and I-gel with head in all the above positions. ProSeal LMA has a better margin of safety than I-gel due to better sealing pressures except in flexion where the increase in airway pressure is more with the former. Extreme precaution should be taken in flexion position in ProSeal LMA. Sandeep Kumar Mishra, Mohammad Nawaz, M. V. S. Satyapraksh, Satyen Parida, Prasanna Udupi Bidkar, Balachander Hemavathy, and Pankaj Kundra Copyright © 2015 Sandeep Kumar Mishra et al. All rights reserved. Arterial Blood Gas Analysis and the Outcome of Treatment in Tricyclic Antidepressants Poisoned Patients with Benzodiazepine Coingestion Thu, 08 Jan 2015 14:29:48 +0000 Background. Poisoning with tricyclic antidepressants (TCAs) is still a major concern for emergency physicians and intensivists. Concomitant ingestion of other psychoactive drugs especially benzodiazepines with TCAs may make this clinical situation more complex. This study aimed to compare the arterial blood gas (ABG) values and the outcome of treatment in patients with coingestion of TCA and benzodiazepine (TCA + BZD) poisoning and TCA poisoning alone. Methods. In this cross-sectional study which was carried out in a tertiary care university hospital in Iran, clinical and paraclinical characteristics of one hundred forty TCA only or TCA + BZD poisoned patients (aged 18–40 years) were evaluated. ABG analysis was done on admission in both groups. Outcomes were considered as survival with or without complication (e.g., intubation) and the frequency of TCA poisoning complications. Results. Arterial pH was significantly lower in TCA + BZD poisoning group compared with TCA only poisoning group (7.34 ± 0.08 and 7.38 ± 0.08, resp.; ). However, other complications such as seizure, and the need for the endotracheal intubation were not significantly different. All patients in both groups survived. Conclusions. Concomitant TCA plus BZD poisoning may make the poisoned patients prone to a lower arterial pH level on hospital admission which may potentially increases the risk of cardiovascular complications in TCA poisoning. Ahmad Yaraghi, Nastaran Eizadi-Mood, Maryam Katani, Shadi Farsaei, Mahrang Hedaiaty, Seyyed Mohammad Mahdy Mirhosseini, Elham Beheshtian, and Ali Mohammad Sabzghabaee Copyright © 2015 Ahmad Yaraghi et al. All rights reserved. Effect of Ondansetron on the Occurrence of Hypotension and on Neonatal Parameters during Spinal Anesthesia for Elective Caesarean Section: A Prospective, Randomized, Controlled, Double-Blind Study Thu, 08 Jan 2015 10:09:43 +0000 To prevent hypotension during spinal anesthesia for caesarean section, we assessed IV ondansetron of invasive maternal hemodynamic and fetal gazometric parameters. Walid Trabelsi, Chihebeddine Romdhani, Haythem Elaskri, Walid Sammoud, Mohamed Bensalah, Iheb Labbene, and Mustapha Ferjani Copyright © 2015 Walid Trabelsi et al. All rights reserved. The Availability of Advanced Airway Equipment and Experience with Videolaryngoscopy in the UK: Two UK Surveys Mon, 05 Jan 2015 10:16:46 +0000 Fibreoptic intubation, high frequency jet ventilation, and videolaryngoscopy form part of the Royal College of Anaesthetists compulsory higher airway training module. Curriculum delivery requires equipment availability and competent trainers. We sought to establish (1) availability of advanced airway equipment in UK hospitals (Survey I) and (2) if those interested in airway management (Difficult Airway Society (DAS) members) had access to videolaryngoscopes, their basic skill levels and teaching competence with these devices and if they believed that videolaryngoscopy was replacing conventional or fibreoptic laryngoscopy (Survey II). Data was obtained from 212 hospitals (73.1%) and 554 DAS members (27.6%). Most hospitals (202, 99%) owned a fiberscope, 119 (57.5%) had a videolaryngoscope, yet only 62 (29.5%) had high frequency jet ventilators. DAS members had variable access to videolaryngoscopes with Airtraq 319 (59.6%) and Glidescope 176 (32.9%) being the most common. More DAS members were happy to teach or use videolaryngoscopes in a difficult airway than those who had used them more than ten times. The majority rated Macintosh laryngoscopy as the most important airway skill. Members rated fibreoptic intubation and videolaryngoscopy skills equally. Our surveys demonstrate widespread availability of fibreoptic scopes, limited availability of videolaryngoscopes, and limited numbers of experienced videolaryngoscope tutors. Rachel L. Gill, Audrey S. Y. Jeffrey, Alistair F. McNarry, and Geoffrey H. C. Liew Copyright © 2015 Rachel L. Gill et al. All rights reserved. Measurements of Epidural Space Depth Using Preexisting CT Scans Correlate with Loss of Resistance Depth during Thoracic Epidural Catheter Placement Thu, 01 Jan 2015 13:04:57 +0000 Background. Thoracic epidural catheters provide the best quality postoperative pain relief for major abdominal and thoracic surgical procedures, but placement is one of the most challenging procedures in the repertoire of an anesthesiologist. Most patients presenting for a procedure that would benefit from a thoracic epidural catheter have already had high resolution imaging that may be useful to assist placement of a catheter. Methods. This retrospective study used data from 168 patients to examine the association and predictive power of epidural-skin distance (ESD) on computed tomography (CT) to determine loss of resistance depth acquired during epidural placement. Additionally, the ability of anesthesiologists to measure this distance was compared to a radiologist, who specializes in spine imaging. Results. There was a strong association between CT measurement and loss of resistance depth (); the presence of morbid obesity () changed this relationship (). The ability of anesthesiologists to make CT measurements was similar to a gold standard radiologist (all individual ). Conclusions. Overall, this study supports the examination of a recent CT scan to aid in the placement of a thoracic epidural catheter. Making use of these scans may lead to faster epidural placements, fewer accidental dural punctures, and better epidural blockade. Nathaniel H. Greene, Benjamin G. Cobb, Ken F. Linnau, and Christopher D. Kent Copyright © 2015 Nathaniel H. Greene et al. All rights reserved. Comment on “Simulation-Based Mastery Learning with Deliberate Practice Improves Clinical Performance in Spinal Anesthesia” Mon, 15 Dec 2014 07:03:44 +0000 Kieran Walsh Copyright © 2014 Kieran Walsh. All rights reserved. Analgesic Techniques in Hip and Knee Arthroplasty: From the Daily Practice to Evidence-Based Medicine Mon, 17 Nov 2014 07:45:43 +0000 Total hip arthroplasty (THA) and total knee arthroplasty (TKA) are major orthopedic surgery models, addressing mainly ageing populations with multiple comorbidities and treatments, ASA II–IV, which may complicate the perioperative period. Therefore effective management of postoperative pain should allow rapid mobilization of the patient with shortening of hospitalization and social reintegration. In our review we propose an evaluation of the main analgesics models used today in the postoperative period. Their comparative analysis shows the benefits and side effects of each of these methods and guides us to how to use evidence-based medicine in our daily practice. Denisa Madalina Anastase, Simona Cionac Florescu, Ana Maria Munteanu, Traian Ursu, and Cristian Ioan Stoica Copyright © 2014 Denisa Madalina Anastase et al. All rights reserved. Cost Analysis of Three Techniques of Administering Sevoflurane Wed, 29 Oct 2014 12:18:56 +0000 Background. This study aimed to evaluate and compare total cost of sevoflurane and propofol for 1.0 MAC-hour of anaesthesia, employing three anaesthetic techniques. Methods. Adult patients scheduled for surgical procedures under general anaesthesia anticipated to last approximately an hour were randomized into three groups ( each), to receive anaesthesia using one of the following techniques: low flow technique involving induction with propofol, followed by sevoflurane delivered using initial fresh gas flows of 6 L/min till MAC reached 1.0 and then reduced to 0.5 L/min; alternate method of low flow entailing only a difference in fresh gas flow rates being maintained at 1 L/min throughout; the third technique involving use of sevoflurane for both induction and maintenance of anaesthesia. Results. Cost of sevoflurane to maintain 1 MAC-hour of anaesthesia was clinically least with low flow anaesthesia, though statistically similar amongst the three techniques. Once the cost of propofol used for induction in two of the three groups was added to that of sevoflurane, cost incurred was least with the technique using sevoflurane both for induction and maintenance of anaesthesia, as compared to low flow and alternative low flow techniques, a 26% and 32% cost saving, respectively (). Asha Tyagi, Vineeta Venkateswaran, Ajai Kumar Jain, and Uttam Chandra Verma Copyright © 2014 Asha Tyagi et al. All rights reserved. Breast Surgery Using Thoracic Paravertebral Blockade and Sedation Alone Thu, 21 Aug 2014 00:00:00 +0000 Introduction. Thoracic paravertebral block (TPVB) provides superior analgesia for breast surgery when used in conjunction with general anesthesia (GA). Although TPVB and GA are often combined, for some patients GA is either contraindicated or undesirable. We present a series of 28 patients who received a TPVB with sedation alone for breast cancer surgery. Methods. A target controlled infusion of propofol or remifentanil was used for conscious sedation. Ultrasound guided TPVB was performed at one, two, or three thoracic levels, using up to 30 mL of local anesthetic. If required, top-up local infiltration analgesia with prilocaine 0.5% was performed by the surgeon. Results. Most patients were elderly with significant comorbidities and had TPVB injections at just one level (54%). Patient choice and anxiety about GA were indications for TVPB in 9 patients (32%). Prilocaine top-up was required in four (14%) cases and rescue opiate analgesia in six (21%). Conclusions. Based on our technique and the outcome of the 28 patients studied, TPVB with sedation and ultrasound guidance appears to be an effective and reliable form of anesthesia for breast surgery. TPVB with sedation is a useful anesthetic technique for patients in which GA is undesirable or poses an unacceptable risk. James Simpson, Arun Ariyarathenam, Julie Dunn, and Pete Ford Copyright © 2014 James Simpson et al. All rights reserved. Anaesthetic Management of Renal Transplant Surgery in Patients of Dilated Cardiomyopathy with Ejection Fraction Less Than 40% Tue, 19 Aug 2014 07:02:49 +0000 Cardiovascular disease (CVD) is an important comorbidity of chronic kidney disease, and reducing cardiovascular events in this population is an important goal for the clinicians who care for chronic kidney disease patients. The high risk for CVD in transplant recipients is in part explained by the high prevalence of conventional CVD risk factors (e.g., diabetes, hypertension, and dyslipidemia) in this patient population. Current transplant success allows recipients with previous contraindications to transplant to have access to this procedure with more frequency and safety. Herein we provide a series of eight patients with dilated cardiomyopathy with poor ejection fraction posted for live donor renal transplantation which was successfully performed under regional anesthesia with sedation. Divya Srivastava, Tanmay Tiwari, Sandeep Sahu, Abhilash Chandra, and Sanjay Dhiraaj Copyright © 2014 Divya Srivastava et al. All rights reserved. Calculation of the Respiratory Modulation of the Photoplethysmogram (DPOP) Incorporating a Correction for Low Perfusion Thu, 07 Aug 2014 11:19:40 +0000 DPOP quantifies respiratory modulations in the photoplethysmogram. It has been proposed as a noninvasive surrogate for pulse pressure variation (PPV) used in the prediction of the response to volume expansion in hypovolemic patients. The correlation between DPOP and PPV may degrade due to low perfusion effects. We implemented an automated DPOP algorithm with an optional correction for low perfusion. These two algorithm variants (DPOPa and DPOPb) were tested on data from 20 mechanically ventilated OR patients split into a benign “stable region” subset and a whole record “global set.” Strong correlation was found between DPOP and PPV for both algorithms when applied to the stable data set: for DPOPa/DPOPb. However, a marked improvement was found when applying the low perfusion correction to the global data set: for DPOPa/DPOPb. Sensitivities, Specificities, and AUCs were 0.86, 0.70, and 0.88 for DPOPa/stable region; 0.89, 0.82, and 0.92 for DPOPb/stable region; 0.81, 0.61, and 0.73 for DPOPa/global region; 0.83, 0.76, and 0.86 for DPOPb/global region. An improvement was found in all results across both data sets when using the DPOPb algorithm. Further, DPOPb showed marked improvements, both in terms of its values, and correlation with PPV, for signals exhibiting low percent modulations. Paul S. Addison, Rui Wang, Scott J. McGonigle, Alberto A. Uribe, and Sergio D. Bergese Copyright © 2014 Paul S. Addison et al. All rights reserved. Simulation-Based Mastery Learning with Deliberate Practice Improves Clinical Performance in Spinal Anesthesia Wed, 16 Jul 2014 11:08:32 +0000 Introduction. Properly performing a subarachnoid block (SAB) is a competency expected of anesthesiology residents. We aimed to determine if adding simulation-based deliberate practice to a base curriculum improved performance of a SAB. Methods. 21 anesthesia residents were enrolled. After baseline assessment of SAB on a task-trainer, all residents participated in a base curriculum. Residents were then randomized so that half received additional deliberate practice including repetition and expert-guided, real-time feedback. All residents were then retested for technique. SABs on all residents’ next three patients were evaluated in the operating room (OR). Results. Before completing the base curriculum, the control group completed 81% of a 16-item performance checklist on the task-trainer and this increased to 91% after finishing the base curriculum (). The intervention group also increased the percentage of checklist tasks properly completed from 73% to 98%, which was a greater increase than observed in the control group (). The OR time required to perform SAB was not different between groups. Conclusions. The base curriculum significantly improved resident SAB performance. Deliberate practice training added a significant, independent, incremental benefit. The clinical impact of the deliberate practice intervention in the OR on patient care is unclear. Ankeet D. Udani, Alex Macario, Kiruthiga Nandagopal, Maria A. Tanaka, and Pedro P. Tanaka Copyright © 2014 Ankeet D. Udani et al. All rights reserved. Problem-Based Learning Research in Anesthesia Teaching: Current Status and Future Perspective Thu, 29 May 2014 05:51:33 +0000 The teaching curriculum in anesthesia involves traditional teaching methods like topic-based didactic lectures, seminars, and journal clubs; intraoperative apprenticeship; and problem-based learning (PBL) and simulation. The advantages of incorporating PBL in anesthesia teaching include development of skills like clinical reasoning, critical thinking, and self-directed learning; in addition it also helps in developing a broader perspective of case scenarios. The present paper discusses the characteristics, key elements, and goals of PBL; various PBL methods available; lacunae in the existing knowledge of PBL research; its current status and future perspectives in anesthesia teaching. G. Chilkoti, M. Mohta, R. Wadhwa, and A. K. Saxena Copyright © 2014 G. Chilkoti et al. All rights reserved. A Triple-Masked, Randomized Controlled Trial Comparing Ultrasound-Guided Brachial Plexus and Distal Peripheral Nerve Block Anesthesia for Outpatient Hand Surgery Tue, 15 Apr 2014 12:56:28 +0000 Background. For hand surgery, brachial plexus blocks provide effective anesthesia but produce undesirable numbness. We hypothesized that distal peripheral nerve blocks will better preserve motor function while providing effective anesthesia. Methods. Adult subjects who were scheduled for elective ambulatory hand surgery under regional anesthesia and sedation were recruited and randomly assigned to receive ultrasound-guided supraclavicular brachial plexus block or distal block of the ulnar and median nerves. Each subject received 15 mL of 1.5% mepivacaine at the assigned location with 15 mL of normal saline injected in the alternate block location. The primary outcome (change in baseline grip strength measured by a hydraulic dynamometer) was tested before the block and prior to discharge. Subject satisfaction data were collected the day after surgery. Results. Fourteen subjects were enrolled. Median (interquartile range [IQR]) strength loss in the distal group was 21.4% (14.3, 47.8%), while all subjects in the supraclavicular group lost 100% of their preoperative strength, P = 0.001. Subjects in the distal group reported greater satisfaction with their block procedures on the day after surgery, P = 0.012. Conclusion. Distal nerve blocks better preserve motor function without negatively affecting quality of anesthesia, leading to increased patient satisfaction, when compared to brachial plexus block. Nicholas C. K. Lam, Matthew Charles, Deana Mercer, Codruta Soneru, Jennifer Dillow, Francisco Jaime, Timothy R. Petersen, and Edward R. Mariano Copyright © 2014 Nicholas C. K. Lam et al. All rights reserved. Attenuation of Hemodynamic Responses to Laryngoscopy and Tracheal Intubation: Propacetamol versus Lidocaine—A Randomized Clinical Trial Sun, 13 Apr 2014 13:13:12 +0000 The purpose of this study is to assess the effects of propacetamol on attenuating hemodynamic responses subsequent laryngoscopy and tracheal intubation compared to lidocaine. In this randomized clinical trial, 62 patients with the American Anesthesiologists Society (ASA) class I/II who required laryngoscopy and tracheal intubation for elective surgery were assigned to receive propacetamol 2 g/I.V./infusion (group P) or lidocaine 1.5 mg/kg (group L) prior to laryngoscopy. Systolic and diastolic blood pressures (SBP, DBP), mean arterial pressure (MAP), and heart rate (HR) were recorded at baseline, before laryngoscopy and within nine minutes after intubation. In both groups P and L, MAP increased after laryngoscopy and the changes were statistically significant (). There were significant changes of HR in both groups after intubation (), but the trend of changes was different between two groups (). In group L, HR increased after intubation and its change was statistically significant within 9 minutes after intubation (), while in group P, HR remained stable after intubation (). Propacetamol 2 gr one hour prior intubation attenuates heart rate responses after laryngoscopy but is not effective to prevent acute alterations in blood pressure after intubation. Ali Kord Valeshabad, Omid Nabavian, Keramat Nourijelyani, Hadi Kord, Hossein Vafainejad, Reza Kord Valeshabad, Ali Reza Feili, Mehdi Rezaei, Hamed Darabi, Mohammad Koohkan, Poorya Golbinimofrad, and Samira Jafari Copyright © 2014 Ali Kord Valeshabad et al. All rights reserved. Obstetric Patients Requiring Intensive Care: A One Year Retrospective Study in a Tertiary Care Institute in India Tue, 25 Mar 2014 13:33:47 +0000 Background and Objectives. Critically ill obstetric patients are a particularly unique cohort for the intensivist. The objective of this study was to review the indications for admission, demographics, clinical characteristics, and outcomes of obstetric patients admitted to intensive care unit of a medical college hospital in southern India and to identify conditions associated with maternal mortality. Design. Retrospective analysis of pregnant/postpartum (up to 6 weeks) admissions over a 1-year result. We studied 55 patients constituting 11.6% of mixed ICU admissions during the study period. Results. The mean APACHE (acute physiology and chronic health evaluation) II score of patients at admission was 11.8. Most of the patients (76%) were admitted in the antepartum period. The commonest indications for ICU admission were obstetric haemorrhage (51%) and hypertensive disorders of pregnancy (18%). 85% of patients required mechanical ventilation and 78% required inotropic support. Conclusions. Maternal mortality was 13%, and the majority of the deaths were due to disseminated intravascular coagulation and multiorgan failure, following an obstetric haemorrhage. A dedicated obstetric ICU in tertiary hospitals can ensure that there is no delay in patient management and intensive care can be instituted at the earliest. Niyaz Ashraf, Sandeep Kumar Mishra, Pankaj Kundra, P. Veena, S. Soundaraghavan, and S. Habeebullah Copyright © 2014 Niyaz Ashraf et al. All rights reserved. Sugammadex and Ideal Body Weight in Bariatric Surgery: The Debate Continues Thu, 13 Mar 2014 12:37:00 +0000 Michele Carron Copyright © 2014 Michele Carron. All rights reserved. Controversies in the Anesthetic Management of Intraoperative Rupture of Intracranial Aneurysm Mon, 03 Mar 2014 11:38:14 +0000 Despite great advancements in the management of aneurysmal subarachnoid hemorrhage (SAH), outcomes following SAH rupture have remained relatively unchanged. In addition, little data exists to guide the anesthetic management of intraoperative aneurysm rupture (IAR), though intraoperative management may have a significant effect on overall neurological outcomes. This review highlights the various controversies related to different anesthetic management related to aneurysm rupture. The first controversy relates to management of preexisting factors that affect risk of IAR. The second controversy relates to diagnostic techniques, particularly neurophysiological monitoring. The third controversy pertains to hemodynamic goals. The neuroprotective effects of various factors, including hypothermia, various anesthetic/pharmacologic agents, and burst suppression, remain poorly understood and have yet to be further elucidated. Different management strategies for IAR during aneurysmal clipping versus coiling also need further attention. Tumul Chowdhury, Andrea Petropolis, Marshall Wilkinson, Bernhard Schaller, Nora Sandu, and Ronald B. Cappellani Copyright © 2014 Tumul Chowdhury et al. All rights reserved. Learning Curves of Macintosh Laryngoscope in Nurse Anesthetist Trainees Using Cumulative Sum Method Wed, 12 Feb 2014 13:02:21 +0000 Background. Tracheal intubation is a potentially life-saving procedure. This skill is taught to many anesthetic healthcare professionals, including nurse anesthetists. Our goal was to evaluate the learning ability of nurse anesthetist trainees in their performance of orotracheal intubation with the Macintosh laryngoscope. Methods. Eleven nurse anesthetist trainees were enrolled in the study during the first three months of their training. All trainees attended formal lectures and practice sessions with manikins at least one time on performing successful tracheal intubation under supervision of anesthesiology staff. Learning curves for each nurse anesthetist trainee were constructed with the standard cumulative summation (cusum) methods. Results. Tracheal intubation was attempted on 388 patients. Three hundred and six patients (78.9%) were successfully intubated on the trainees’ first attempt and 17 patients (4.4%) on the second attempt. The mean SD number of orotracheal intubations per trainee was (range 30–47). Ten (90.9%) of 11 trainees crossed the 20% acceptable failure rate line. A median of 22 procedures was required to achieve an 80% orotracheal intubations success rate. Conclusion. At least 22 procedures were required to reach an 80% success rate for orotracheal intubation using Macintosh laryngoscope in nonexperienced nurse anesthetist trainees. Panthila Rujirojindakul, Edward McNeil, Rongrong Rueangchira-urai, and Niranuch Siripunt Copyright © 2014 Panthila Rujirojindakul et al. All rights reserved. Prediction of Optimal Reversal Dose of Sugammadex after Rocuronium Administration in Adult Surgical Patients Tue, 11 Feb 2014 12:55:13 +0000 The objective of this study was to determine the point after sugammadex administration at which sufficient or insufficient dose could be determined, using first twitch height of train-of-four (T1 height) or train-of-four ratio (TOFR) as indicators. Groups A and B received 1 mg/kg and 0.5 mg/kg of sugammadex, respectively, as a first dose when the second twitch reappeared in train-of-four stimulation, and Groups C and D received 1 mg/kg and 0.5 mg/kg of sugammadex, respectively, as the first dose at posttetanic counts 1–3. Five minutes after the first dose, an additional 1 mg/kg of sugammadex was administered and changes in T1 height and TOFR were observed. Patients were divided into a recovered group and a partly recovered group, based on percentage changes in T1 height after additional dosing. T1 height and TOFR during the 5 min after first dose were then compared. In the recovered group, TOFR exceeded 90% in all patients at 3 min after sugammadex administration. In the partly recovered group, none of the patients had a TOFR above 90% at 3 min after sugammadex administration. An additional dose of sugammadex can be considered unnecessary if the train-of-four ratio is ≥90% at 3 min after sugammadex administration. This trial is registered with UMIN000007245. Shigeaki Otomo, Hajime Iwasaki, Kenichi Takahoko, Yoshiko Onodera, Tomoki Sasakawa, Takayuki Kunisawa, and Hiroshi Iwasaki Copyright © 2014 Shigeaki Otomo et al. All rights reserved. Phenoxybenzamine in Complex Regional Pain Syndrome: Potential Role and Novel Mechanisms Thu, 19 Dec 2013 09:48:29 +0000 There is a relatively long history of the use of the α-adrenergic antagonist, phenoxybenzamine, for the treatment of complex regional pain syndrome (CRPS). One form of this syndrome, CRPS I, was originally termed reflex sympathetic dystrophy (RSD) because of an apparent dysregulation of the sympathetic nervous system in the region of an extremity that had been subjected to an injury or surgical procedure. The syndrome develops in the absence of any apparent continuation of the inciting trauma. Hallmarks of the condition are allodynia (pain perceived from a nonpainful stimulus) and hyperalgesia (exaggerated pain response to a painful stimulus). In addition to severe, unremitting burning pain, the affected limb is typically warm and edematous in the early weeks after trauma but then progresses to a primarily cold, dry limb in later weeks and months. The later stages are frequently characterized by changes to skin texture and nail deformities, hypertrichosis, muscle atrophy, and bone demineralization. Earlier treatments of CRPS syndromes were primarily focused on blocking sympathetic outflow to an affected extremity. The use of an α-adrenergic antagonist such as phenoxybenzamine followed from this perspective. However, the current consensus on the etiology of CRPS favors an interpretation of the symptomatology as an evidence of decreased sympathetic activity to the injured limb and a resulting upregulation of adrenergic sensitivity. The clinical use of phenoxybenzamine for the treatment of CRPS is reviewed, and mechanisms of action that include potential immunomodulatory/anti-inflammatory effects are presented. Also, a recent study identified phenoxybenzamine as a potential intervention for pain mediation from its effects on gene expression in human cell lines; on this basis, it was tested and found to be capable of reducing pain behavior in a classical animal model of chronic pain. Mario A. Inchiosa Jr. Copyright © 2013 Mario A. Inchiosa Jr. All rights reserved. The Association of Postcardiac Surgery Acute Kidney Injury with Intraoperative Systolic Blood Pressure Hypotension Thu, 14 Nov 2013 10:32:05 +0000 Background. Postoperative acute kidney injury (AKI) is associated with high mortality and substantial cost after aortocoronary bypass graft (CABG) surgery. We tested the hypothesis that intraoperative systolic blood pressure variation is associated with postoperative AKI. Methods. We gathered demographic, procedural, blood pressure, and renal outcome data for 7,247 CABG surgeries at a single institution between 1996 and 2005. A development/validation cohort methodology was randomly divided (66% and 33%, resp.). Peak postoperative serum creatinine rise relative to baseline (%ΔCr) was the primary AKI outcome variable. Markers reflective of intraoperative systolic blood pressure variation were derived for each patient including (1) peak and nadir values (absolute and relative to baseline) and (2) excursion episodes beyond selected thresholds (by duration, frequency, and duration × degree). Each marker of systolic blood pressure variation was then separately evaluated for association with AKI using linear regression models with adjustment for several known risk factors (age, aprotinin use, congestive heart failure, previous myocardial infarction, baseline creatinine, bypass time, diabetes, weight, concomitant valve surgery, gender, and preoperative pulse pressure). Results. An association was identified between systolic blood pressure relative to baseline and postoperative AKI (). Conclusions. In CABG surgery patients, intraoperative systolic blood pressure decrease relative to baseline systolic blood pressure is independently associated with postoperative AKI. Solomon Aronson, Barbara Phillips-Bute, Mark Stafford-Smith, Manuel Fontes, Jeffrey Gaca, Joseph P. Mathew, and Mark F. Newman Copyright © 2013 Solomon Aronson et al. All rights reserved. Supraventricular Arrhythmias after Thoracotomy: Is There a Role for Autonomic Imbalance? Wed, 23 Oct 2013 13:53:14 +0000 Supraventricular arrhythmias are common rhythm disturbances following pulmonary surgery. The overall incidence varies between 3.2% and 30% in the literature, while atrial fibrillation is the most common form. These arrhythmias usually have an uneventful clinical course and revert to normal sinus rhythm, usually before patent’s discharge from hospital. Their importance lies in the immediate hemodynamic consequences, the potential for systemic embolization and the consequent long-term need for prophylactic drug administration, and the increased cost of hospitalization. Their incidence is probably related to the magnitude of the performed operative procedure, occurring more frequently after pneumonectomy than after lobectomy. Investigators believe that surgical factors (irritation of the atria per se or on the ground of chronic inflammation of aged atria), direct injury to the anatomic structure of the autonomic nervous system in the thoracic cavity, and postthoracotomy pain may contribute independently or in association with each other to the development of these arrhythmias. This review discusses currently available information about the potential mechanisms and risk factors for these rhythm disturbances. The discussion is in particular focused on the role of postoperative pain and its relation to the autonomic imbalance, in an attempt to avoid or minimize discomfort with proper analgesia utilization. George Vretzakis, Marina Simeoforidou, Konstantinos Stamoulis, and Metaxia Bareka Copyright © 2013 George Vretzakis et al. All rights reserved. Interaction of Local Anesthetics with Biomembranes Consisting of Phospholipids and Cholesterol: Mechanistic and Clinical Implications for Anesthetic and Cardiotoxic Effects Mon, 23 Sep 2013 11:17:57 +0000 Despite a long history in medical and dental application, the molecular mechanism and precise site of action are still arguable for local anesthetics. Their effects are considered to be induced by acting on functional proteins, on membrane lipids, or on both. Local anesthetics primarily interact with sodium channels embedded in cell membranes to reduce the excitability of nerve cells and cardiomyocytes or produce a malfunction of the cardiovascular system. However, the membrane protein-interacting theory cannot explain all of the pharmacological and toxicological features of local anesthetics. The administered drug molecules must diffuse through the lipid barriers of nerve sheaths and penetrate into or across the lipid bilayers of cell membranes to reach the acting site on transmembrane proteins. Amphiphilic local anesthetics interact hydrophobically and electrostatically with lipid bilayers and modify their physicochemical property, with the direct inhibition of membrane functions, and with the resultant alteration of the membrane lipid environments surrounding transmembrane proteins and the subsequent protein conformational change, leading to the inhibition of channel functions. We review recent studies on the interaction of local anesthetics with biomembranes consisting of phospholipids and cholesterol. Understanding the membrane interactivity of local anesthetics would provide novel insights into their anesthetic and cardiotoxic effects. Hironori Tsuchiya and Maki Mizogami Copyright © 2013 Hironori Tsuchiya and Maki Mizogami. All rights reserved.