Intraoperative Patient Monitoring Research Articles

Fluorescence-guided surgery in patients with tumors near motor areas of the brain

There is no common concept regarding the effectiveness of the use of fluorescence-guided surgery in patients with tumors located in eloquent areas of the brain, in which resection can be stopped because the high risk of an increase of neurological deficit. Objective is to evaluate the effectiveness of fluorescence-guided surgery in patients with tumors located near the motor cortex and corticospinal tract. Methods. Our research includes 108 adult patients with gliomas near the motor cortex and corticospinal tract divided into two groups depending on the use of fluorescence-guided surgery: control (34 patients without fluorescence) and main (62 patients with fluorescence). Results. There is no difference between study groups in the radicality of surgery and neurological outcomes. Conclusion. Fluorescence-guided surgery can be a useful tool as part of complex intraoperative monitoring in patients with tumors located near the motor cortex and corticospinal tract despite the absence of a statistically significant difference.

P01.20.B Peroperative cognitive monitoring in patients with aphasia

Abstract Background Cognitive monitoring during awake glioma surgery provides the opportunity to increase the extent of resection while preserving cognitive functions. Preoperative language functioning often determines whether awake surgery can be performed since some form of communication with the patient is essential. However, as complex as it may be to perform intraoperative monitoring in patients with severe preoperative language disturbances, it is risky to assume that language disturbances are definite without functional perspectives. In addition, there are other cognitive functions that should be preserved. This study investigates to what extent cognitive functions can be monitored during awake surgery in the presence of preoperative language disturbances. Material and Methods Glioma data were collected in a single-centre consecutive study cohort of 186 patients who underwent awake brain surgery for either low-grade (WHO grade 1-2) glioma (40 percent) or high-grade (WHO grade 3-4) glioma (60 percent). Preoperative language disturbances were evidenced during preoperative neuropsychological assessment based on performances on the Boston Naming Test (N= 27) and Token Test (N=25). Intraoperative procedures were performed as part of clinical care. Results Preliminary results on the Boston Naming Test show that intraoperative testing with the use of at least one language test (picture-naming) is feasible in 80 percent of all patients with language disturbances. In those cases, a functional boundary of language functions is found in 85 percent during awake surgery. Monitoring of other non-language functions, such as working memory, inhibition, speech, motor functions and social cognition, provided functional boundaries in 25 up to 85 percent of patients with language disturbances. Postoperatively, cognitive functioning was improved in a significant number of patients. Conclusion Based on these preliminary results we conclude that preoperative language disturbances do not prevent from monitoring language functions as well as other cognitive functions during awake glioma surgery. In a larger cohort, more in-depth analyses will be performed on additional outcome measures (Token test, survival rate, post-surgery treatment) and postoperative functioning will be compared to a control group of patients without preoperative language disturbances. By investigating the potential of awake surgery in patients who are severely cognitively affected, we aim to increase the applicability of this method to improve neuro-oncological treatments and optimally maintain quality of life.

ClearSight™ finger cuff versus invasive arterial pressure measurement in patients with body mass index above 45 kg/m2

BackgroundMeasuring blood pressure in patients with obesity is challenging. The ClearSight™ finger cuff (FC) uses the vascular unloading technique to provide continuous non-invasive blood pressure measurements. We aimed to test the agreement of the FC with invasive radial arterial monitoring (INV) in patients with obesity.MethodsParticipants had a body mass index (BMI) ≥45 kg/m2 and underwent laparoscopic bariatric surgery. FC and INV measurements were obtained simultaneously every 5 min on each patient, following induction of anesthesia. Agreement over time was assessed using modified Bland-Altman plots and error grid analysis permitted clinical interpretation of the results. Four-quadrant plots allowed assessment of concordance in blood pressure changes.ResultsThe 30 participants had a median (IQR) BMI of 50.2 kg/m2 (IQR 48.3–55.3). The observed bias (SD, 95% limits of agreement) for systolic blood pressure (SBP) was 14.3 mmHg (14.1, -13.4 – 42.0), 5.2 mmHg (10.9, -16.0 – 26.5) for mean arterial pressure (MAP) and 2.6 mmHg (10.8, -18.6 – 23.8) for diastolic blood pressure (DBP). Error grid analysis showed that the proportion of readings in risk zones A-E were 90.8, 6.5, 2.7, 0 and 0% for SBP and 91.4, 4.3, 4.3, 0 and 0% for MAP, respectively. Discordance occurred in ≤8% of pairs for consecutive change in SBP, MAP and DBP.ConclusionsThe vascular unloading technique was not adequately in agreement with radial arterial monitoring. Evaluation in a larger sample is required before recommending this technique for intraoperative monitoring of patients with BMI ≥45 kg/m2.

The influence of the chosen method of anesthesia on the severity of postoperative cognitive dysfunction in patients with ophthalmic surgery

Reduction of cognitive functions in the postoperative period is gaining importance in the context of the insurance medicine introduction. Operational stress and anaesthetization are factors which increase the risk of deepening and developing postoperative cognitive dysfunction. The function of short-term memory, attention function, and the speed of psychomotor cognitive reactions are the most vulnerable to the action of general anesthetics. The influence of various methods of anesthesia on cognitive functions in ophthalmic surgery patients after end-to-end keratoplasty has been studied in this research work. Dexmedetomidine was used (the selective agonist of α-adrenoreceptors) as one of the components of multimodal anaesthetization. The sedative effect of this drug is explained by inhibition of neural activity in the blue spot of the brain stem. Dexmedetomidine is known to be used for sedation of patients. It allowed possibility to reduce the amount of fentanyl which was necessary for intra-and post-operative anaesthetization. Our research was conducted on the basis of ME "DRCOH". 78 patients at the age of 18 to 60 years were examined after end-to-end keratoplasty. Non-inclusion criteria: presence of concomitant pathology, neurological diseases, use of psychotropic substances and alcohol 6 months before the study. The study was conducted using neuropsychological testing: the Mini Mental State Examination (MMSE),the Frontal Assessment Battery (FAB), and Luria’s test. Testing was performed before the operation, in 6, 24 hours, 7 and 21 days. Patients were randomized into two groups. The first group – group k (n1=45) included patients who were provided with anaesthetic management according to the following scheme:premedication — ondansetron 4 mg, dexamethasone 4 mg, ketorolac 30 mg intravenously, sibazone 10 mg, fentanyl 0.1 mg intramuscularly 40 minutes before intervention. Induction of propofol – 2-2.5 mg/kg fractionally to achieve clinical symptoms of anaesthetization, fentanyl – 0.005% 0.1 mg tracheal intubation after relaxation on the background of atracuriumbenzylate – 0.3-0.6 mg/kg. Maintaining of anaesthetization: oxygen-sevoflurane mixture FiO250-55%, sevoflurane 1,4-1,8 vol.% on exhalation (1-1. 5 WT.) with the flow of no more than 1 l/min. BIS indicators were kept at the level of 30-40, during the surgery, the bolus injection of 0.1 mg of fentanyl was used in the event of hemodynamic reactions. Anaesthetic support was performed using the infusion of dexmedetomidin for 40 minutes, ondansetron 4 mg, dexamethasone 4 mg, ketorolac 30 mg intravenously in the second group d (n2=33). Induction, relaxation and maintenance of anaesthetization were performed as in the previous group. Intra-operative monitoring of patients in both groups included: non-invasive measurement of blood pressure (BP), heart rate (HR), pulse oximetry, determination of blood gases (oxygen, carbon dioxide and inhaled anesthetic on inhalation and exhalation). Control of the depth of anaesthetization was performed on the basis of BIS and ANI - monitoring. The use of dexmedetomidinu as the component of a multi-modal method of anaesthetizational al lowed obtaining less pronounced POCD, due to the reduction in the number of used drugs. Further use of the combination of highly selective agonists of α2-adrenoreceptors with regional anaesthetization in ophthalmic surgery is the promising method.

P013: Emergency medicine in dental practice: shaping an educational curriculum

Introduction: There is increasing public demand for dentists and their professional regulators to mitigate medical risk to patients in private dental clinics – especially those that offer procedural sedation. Recent high-profile adverse events reported in the media suggest an urgent need to address this issue. However, there is a paucity of knowledge in the literature regarding how best to do so. We aim to explore opportunities for multidisciplinary emergency medical training of dentists, and to offer an informed perspective to assist with the preliminary development of a structured educational program. Methods: We employ Gioia Methodology, an established standard for inductive qualitative research and thematic analysis. Interviewees were recruited via email and selected to ensure a broad and knowledgeable perspective. We conducted individual semi-structured 1-hour interviews of 6 dentists, 4 medical anesthesiologists, 3 emergency physicians, and 1 oral and maxillofacial surgeon. Several interviewees had leadership roles in Canadian dental regulatory agencies and educational institutions. Data from these interviews was contemporaneously analyzed and organized into “first-order concepts”, “second-order themes” and “aggregate dimensions.” Results: Our findings demonstrated 12 first-order concepts. Dentists require "leadership from professional regulators", and "accreditation by recognized training institutions" to "ensure competence in initial emergency medical care of patients". "Customized training programs" led by "multidisciplinary instructors" – including emergency physicians – should ensure "pre-operative medical risk assessment", "appropriate intra-operative patient monitoring", and "the ability to recognize common medical emergencies". Emergency medical skills training should focus upon "teamwork within the office", "early activation of EMS", “ABC skills", and the administration of "emergency medications". Conclusion: Dentists require a very broad skillset to safely manage patients in their practice, especially when procedural sedation is required. Our aggregate dimensions provide an overview of our recommendations: we suggest that dentists must work with their regulators and educators to "build upon an existing culture of patient safety" by fostering "competence in the prevention, recognition and initial management of medical emergencies" in the dental practice setting.

Clinical practice in intraoperative haemodynamic monitoring in Poland: a point prevalence study in 31 Polish hospitals.

Appropriate use of haemodynamic monitoring tools facilitates the adjustment of management to the patient's individual needs. The aim of the study was to evaluate clinical practice in intraoperative monitoring of patients undergoing non-cardiac surgical procedures in selected hospitals in Poland. A point prevalence cross-sectional study was carried out among 587 adult patients of 31 Polish hospitals on April 5th, 2018. The method of monitoring in relation to the estimated individual risk as well as to the type and mode of surgery was analysed. In addition, intraoperative fluid therapy and use of catecholamines were evaluated. Basic monitoring based on non-invasive arterial blood pressure measurements was implemented in 562 (96%) patients. More advanced methods of monitoring were used in 25 (4%) patients during moderate- (n = 16) and high-risk (n = 9) procedures, predominantly in high-risk patients (n = 16) and in university hospital settings (n = 21). Patients monitored basically received significantly higher amounts of fluids, i.e. 8.7 (IQR 6.1-12.6) vs. 6.1 (IQR 4.1-8.6) mL kg-1 h-1, respectively (P < 0.001). The most common vasoactive and inotropic drug was ephedrine, administered to 143 (24%) study patients in a dose of 15 mg (IQR 10-25) - without inter-group differences in categories of individual and procedure-related risk. The basic method of haemodynamic monitoring used in the study population was based on non-invasive arterial blood pressure measurements. The advanced tools of intraoperative haemodynamic monitoring were seldom used. Monitoring was not tailored to the perioperative risk.

Chapter 19 - Anesthesia for meningioma surgery

Patients receiving treatment for a meningioma require anesthesia when undergoing open craniotomy and, in some cases, during preoperative tumor embolization and radiosurgery. Adequate anesthesia management is integral to patients' perioperative care, which consists of the three phases of preoperative assessment and optimization, intraoperative care, and postoperative recovery. The preoperative anesthesia evaluation focusses on the cardiorespiratory and neurologic systems, as well as the airway, but also extends to ensure the optimal treatment of significant comorbidities before surgical intervention. The goals of intraoperative care are maintenance of brain physiology, facilitating surgery, and correcting any adverse effects of surgery and underlying pathology to preserve general patient homeostasis. This requires adequate intraoperative patient monitoring, cardiorespiratory support, management of infusion therapy, and application of knowledge about the effects of anesthetic agents on brain physiology. The anesthesiologist's responsibilities for patient care extend well into the postoperative recovery period, with a focus on pain control, prevention, and treatment of postoperative nausea and vomiting (PONV), and, in some patients, intensive care therapy.

Practice Guidelines for Intravenous Conscious Sedation in Dentistry (Second Edition, 2017).

Practice Guidelines for Intravenous Conscious Sedation in Dentistry (Second Edition, 2017).

Usefulness of Direct Cortical Stimulation During Intraoperative Monitoring in Patients with Brain Tumor Near Motor Cortex: Case Report

Usefulness of Direct Cortical Stimulation During Intraoperative Monitoring in Patients with Brain Tumor Near Motor Cortex: Case Report

Perioperative nursing of inner limiting membrane peeling silicone oil plombage on curing yellow spot retinal detachment of high myopia

Objective To discuss about the perioperative nursing method of inner limiting membrane peeling silicone oil plombage on curing yellow spot retinal detachment of high myopia. Methods Preoperative mental nursing, article preparation, intraoperative patient's condition monitoring, postoperative position, prevention and complication nursing were conducted to 60 cases of yellow spot retinal detachment of high myopia by applying inner limiting membrane peeling silicone oil plombage. Results After silicone oil was taken out, the retina of 55 patients(91.67%) was still in place.After silicone oil of 5 patients (8.33%) was taken out, there was retinal detachment, and reoperation was conducted to reset.6 months after operation, there were 15 cases(25.00%) that the vision was recovered to be ≥0.1, 14 cases(23.33%) recovered to be 0.05~0.09, 13 cases(21.67%)recovered to be 0.02~0.04 and 8 cases(13.33%)had index light sensation. Conclusions Give appropriate preoperative psychological nursing, and patients with sufficient preoperative preparation, intraoperative monitoring vital signs, precise surgery and postoperative observation, body position nursing care, prevention of complications, nursing is the guarantee of successful operation, it is also the key to promote the patient choosing. Key words: High myopia; Retinal detachment; Impending macular hole; Silicone oil tamponade; Perioperative nursing

Usefulness of intraoperative electromyographic monitoring of oculomotor and abducens nerves during skull base surgery.

Intraoperative neurophysiologic monitoring of the extraocular cranial nerve (EOCN) is not commonly performed because of technical difficulty and risk, reliability of the result and predictability of the postoperative function of the EOCN. We performed oculomotor nerve (CN III) and abducens nerve (CN VI) intraoperative monitoring in patients with skull base surgery by recording the spontaneous muscle activity (SMA) and compound muscle action potential (CMAP). Two types of needle electrodes of different length were percutaneously inserted into the extraocular muscles with the free-hand technique. We studied the relationships between the SMA and CMAP and postoperative function of CN III and CN VI. A total of 23 patients were included. Nineteen oculomotor nerves and 22 abducens nerves were monitored during surgery, respectively. Neurotonic discharge had a positive predictive value of less than 50% and negative predictive value of more than 80% for postoperative CN III and CN VI dysfunction. The latency of patients with postoperative CN III dysfunction was 2.79±0.13ms, longer than that with intact CN III function (1.73±0.11ms). One patient had transient CN VI dysfunction, whose CMAP latency (2.54ms) was longer than that of intact CN VI function (2.11±0.38ms). There was no statistically significant difference between patients with paresis and with intact function. The method of intraoperative monitoring of EOCNs described here is safe and useful to record responses of SMA and CMAP. Neurotonic discharge seems to have limited value in predicting the postoperative function of CN III and CN VI. The onset latency of CMAP longer than 2.5ms after tumor removal is probably relevant to postoperative CN III and CN VI dysfunction. However, a definite quantitative relationship has not been found between the amplitude and stimulation intensity of CMAP and the postoperative outcome of CN III and CN VI.

Monitoring rate and predictability of intraoperative monitoring in patients with intradural extramedullary and epidural metastatic spinal tumors.

Single-center retrospective study. To evaluate the monitoring rate, sensitivity and specificity of intraoperative monitoring (IOM) during removal of intradural extramedullary (IDEM) or epidural metastatic spinal tumors. Also, to assess the efficacy of monitoring somatosensory-evoked potentials (SSEP) when motor-evoked potentials (MEP) are not measurable. The Neuro-Oncology Clinic, National Cancer Center, Korea. Patients (n=101) with IDEM or epidural metastatic spinal tumors at the cord level underwent surgeries monitored with SSEP and/or MEP. The monitoring rate was defined as negative when MEP or SSEP could not be measured after reversal of the neuromuscular block under general anesthesia. Positive IOM changes included more than a 50% change in the MEP or SSEP amplitude and more than a 10% delay in SSEP latency. MEP was measurable in 73% of patients. The MEP monitoring rate in patients with motor power grades of 3 or less was 39%, which was lower than that of SSEP (83%). The sensitivity, specificity and predictability of MEP for motor changes were 93, 90 and 91%, respectively. Conversely, the sensitivity, specificity and predictability of SSEP were 62, 97 and 89%, respectively. In patients in whom MEP was not measurable (n=24), SSEP was monitored with a predictability of 83%. In cases of extramedullary spinal tumors, MEP shows a higher sensitivity than SSEP does. However, the monitoring rate of MEP in non-ambulatory patients was lower than that of SSEP. In those cases, SSEP can be useful to monitor for postoperative neurological deficits.

Pre- and perioperative aspects of dermatosurgery.

Dermatosurgery occupies an exceptional position among all surgical disciplines. Above all, this includes the fact that, with very few exceptions, the vast majority of surgical interventions can be performed under local or regional anesthesia, usually in smaller procedure rooms that are spatially separated from larger operating suites. Thus, peri- and postinterventional patient monitoring is the responsibility of the dermatosurgeon and his team. Though inherently smaller, this team still has to observe numerous perioperative requirements that - in larger surgical specialties - would be attended to by a host of various specialists working in concert. Said requirements include hygienic aspects, knowledge concerning pre- and intraoperative patient monitoring, managing surgical site infections, adequate postsurgical pain management, as well as detailed pharmacological knowledge with respect to common local anesthetics and the toxic and allergic reactions associated therewith. Not only does this require interdisciplinary collaboration and shared responsibility for the patient. It also necessitates the development and implementation of quality-oriented and evidence-based guidelines that, in the dermatosurgical setting, usually extend far beyond the scope of the specialty per se. The objective of the present CME article is the condensed presentation of interdisciplinary aspects relating to the most important perioperative issues.

STRESS-RESPONSE TO RADICAL SURGERIES FOR GASTRIC CANCER

The purpose of the study was to evaluate the anesthetic effect of the combination of xenon and dexmedetomidine during surgery for gastric cancer. Material and methods. The prospective randomized study included 53 patients with operable II–III stage gastric cancer. The age range was from 26 to 75 years. The patients underwent gastrectomy (n=21) and subtotal distal gastrectomy (n=32). The study group comprised 27 patients who received anesthesia with xenon and dexmedetomidine combined with epidural analgesia. The control group consisted of 26 patients who received anesthesia with sevoflurane in combination with epidural analgesia. Intraoperative patient monitoring was performed according to Harvard intraoperative monitoring standards. Plasma levels of ACTH, STH cortisole, IL-1β, IL-6, and CRP as well as cytokine profile were used to evaluate the effect of two anesthetic methods. Results. In the perioperative period, the combination of xenon and dexmedetomidine in combination with epidural analgesia was characterized by significant inhibition of systemic inflammatory reactions and a lower release of stress hormones as components of a surgical stress response expressed by a lower level of pro-inflammatory cytokines and somatotropic hormone. The frequency of postoperative inflammatory complications was lower in the xenon group than in the control group. Conclusion. The use of the combination of xenon and dexmedetomidine during surgery for gastric cancer provides a more adequate course of the perioperative period.

Diagnostic Accuracy of Combined Multimodality Somatosensory Evoked Potential and Transcranial Motor Evoked Potential Intraoperative Monitoring in Patients With Idiopathic Scoliosis.

Systematic review. The aim of the study was to determine the predictive value of combined multimodality somatosensory evoked potential (SSEP) and transcranial motor evoked potential (TcMEP) monitoring in detecting impending neurological injury during surgery for idiopathic scoliosis. The diagnostic of motor evoked potential monitoring and SSEP monitoring have been established. However, the predictive value of combined multimodality SSEP and TcMEP monitoring in detecting impending neurological injury during surgery for idiopathic scoliosis has not been evaluated. A systematic literature search was performed using PubMed/MEDLINE, Web of Science, and EMBASE from 1974 to January 2015. All titles and abstracts were independently reviewed by the authors. We included all studies that were (1) randomized controlled trials, prospective or retrospective cohort studies; (2) included patients with idiopathic scoliosis undergoing scoliosis correction surgery; (3) included multimodality SSEP and TcMEP monitoring during spinal surgery; (4) included immediate postoperative neurological assessment; (5) idiopathic scoliosis patient population n ≥25; and (6) published in English. Seven studies comprising a total of 2052 patients with idiopathic scoliosis were included in our meta-analysis. The incidence of neurological deficit in this cohort was 0.93%. The pooled sensitivity, specificity, and Diagnostic Odds Ratio were 82.6% (95% CI 56.7%-94.5%), 94.4% (95% CI 85.1%-98.0%), and 106.16 (95% CI 24.952-451.667), respectively. The area under the curve was 0.928, indicating excellent discriminatory ability. Idiopathic scoliosis corrective surgery patients who experience a new neurological deficit are 106.16 times more likely to have had an SSEP and/or TcMEP change during corrective procedures. The results of this meta-analysis demonstrate that combined multimodality SSEP and TcMEP monitoring possess some advantage over use of each alone, and that intraoperative neurophysiological monitoring may provide a valuable biomarker in detection of impending neurological injury. 2.

Feasibility and Predictability of Intraoperative Monitoring in Patients with Intradural Extramedullary and Epidural Metastatic Spinal Tumors

Objectives: To evaluate the feasibility, sensitivity and specificity of IOM for IDEM and ED metastatic spinal tumours, and to assess usefulness of SSEP for patients in whom MEP was not measurable. Methods and materials: One hundred and one consecutive patients with IDEM and ED metastatic spinal tumours at the cord level (C1 to L1) received surgery under SSEP and/or MEP was included. Feasibility of IOM was defined to be negative in case of no measurable MEP or SSEP under general anaesthesia after confirmation of reversal of neuromuscular block. More than 50% change of MEP or SSEP amplitude and more than 10% delay of SSEP latency were evaluated as positive signs of IOM change. Results: MEP was measurable in 74 out of 101 trials, thus feasibility is 73%. Patient with normal motor power showed higher feasibility than those with motor power 3 or less. (93% vs. 39%) Among 74 patients with measurable MEP, 19 patients showed positive MEP change and 14 patients got worse of their motor power postoperatively.

The safety of transesophageal echocardiography in patients undergoing orthotopic liver transplantation.

To evaluate the safety of transesophageal echocardiography for the evaluation and intraoperative monitoring of patients during orthotopic liver transplantation. Retrospective observational study. Tertiary care, university teaching hospital. Patients (n = 116) who underwent intraoperative transesophageal echocardiography during liver transplantation. Intraoperative transesophageal echocardiography during liver transplantation. The authors evaluated the safety of intraoperative transesophageal echocardiography in patients undergoing liver transplantation through a retrospective chart review. Complications associated with transesophageal echocardiography use were divided into minor and major complications. Out of 116 patients who underwent intraoperative transesophageal echocardiography, there was one minor and one major complication. The major complication rate was 0.86% (1/116) and the overall complication rate was 1.7% (2/116). There was no statistically significant correlation between pre-transplant sclerotherapy for treatment of varices and intraoperative transesophageal echocardiography-related gastrointestinal bleeding. Although the reported complication rate is higher than what has been quoted in the cardiac literature, intraoperative transesophageal echocardiography during liver transplantation has a low complication rate. Intraoperative transesophageal echocardiography is a relatively safe method of monitoring cardiac performance in liver transplant patients.

A-trains for intraoperative monitoring in patients with recurrent vestibular schwannoma

Second surgery of recurrent vestibular schwannoma (VS) after previous surgery, stereotactic radiosurgery (SR) or fractionated radiotherapy (FR) carries an increased risk for deterioration of facial nerve function, e.g., due to adhesions, underlining the need for intraoperative monitoring. Facial “Atrain” EMG activity (“traintime”) correlates with the degree of postoperative facial palsy. Studies investigating A-trains in VS patients with previous surgery, SR or FR are missing. We therefore investigated the value of A-train monitoring in patients undergoing second surgery for VS. Intraoperative EMG data from patients who underwent second surgery for VS after previous surgery, SR and/or FR at our institution between 2006 and 2012 were retrospectively analyzed. Ten patients were selected (5 male): Seven had previous SR/RT and MS, three previous surgery only. Traintime values and distribution was compared to published thresholds and to 77 patients who underwent first surgery for VS during the same time period. A-trains were recorded early after opening of the dura, before facial nerve preparation. Mean traintime was 46.9 s (18.51 s – 80.82 s) in patients with previous SR/RT. In patients with previous MS only, traintime was 0.06 s, 0.99 s and 22.46 s. Compared to the literature, traintime was higher than expected in six patients (four with previous SR/RT, two without), respectively seven compared to the 77 patients with first surgery (5 SR/RT). Seven patients with previous SR/RT and none with previous surgery showed diffuse A-train distributions without significant percentages in single channels, compared to 60 of 77 patients with first surgery (p <0.02). Especially SR/RT, but also previous surgery seems to induce changes in the facial nerve leading to hyperexcitability and exceedingly high traintime values. Based on these findings, A-train monitoring in this specific patient group should be interpreted with caution.

Anesthetic Management of a Pediatric Patient with Leigh Syndrome

Background and objectivesLeigh syndrome (LS) is a rare disease caused by abnormalities of mitochondrial energy generation. The central nervous system is most frequently affected, with psychomotor underdevelopment, seizures, nystagmus, ophthalmoparesis, optic atrophy, ataxia, dystonia, or respiratory failure. Surgical and anesthetic procedures stimulate the tracheal irritability, and could exacerbate risks of aspiration, wheezing, breathing diffi culties, gasping, hypoventilation, and apnea. Case ReportWe present the anesthetic management for a six-year-old boy with severe form of LS, involving repair of a femur fracture. Propofol and remifentanil were infused for general anesthesia. The patient was closely monitored during anesthesia and in the intensive care unit in the early postoperative period. ConclusionsClose intraoperative monitoring of patients, including invasive arterial blood pressure monitoring and frequently measuring the levels of blood gases, glucose, and lactate, made this procedure run smoothly. Intensive care and breathing support for the patient with LS, under sedation with an analgesic combination during the early postoperative period, minimized the stress response due to pain after surgery.

Monitoring Cardiac Output Trends With End-Tidal Carbon Dioxide Pressures in Off-Pump Coronary Bypass

The optimum method of intraoperative monitoring in patients undergoing off-pump coronary bypass remains debatable. Using capnography and end-tidal carbon dioxide pressure may be a helpful method of monitoring cardiac output trends, especially when grafting posterior and lateral vessels. After repositioning the heart, End-tidal carbon dioxide pressures that continue to trend down usually indicate decreased cardiac output and precede hemodynamic and electrical instability. The advantages of this method include simplicity, universal availability, and a short response time to changes in cardiac output.