Intraoperative Wake-up Test Research Articles

Delayed postoperative neurological deficits from scoliosis correction: a case series and systematic review on clinical characteristics, treatment, prognosis, and recovery.

This study was designed to investigate the clinical features, treatment modalities, and risk factors influencing neurological recovery in patients who underwent scoliosis correction with delayed postoperative neurological deficit (DPND). Three patients with DPND were identified from 2 central databases for descriptive analysis. Furthermore, all DPND cases were retrieved from the PubMed and Embase databases. Neurological function recovery was categorized into complete and incomplete recovery groups based on the American Spinal Injury Association (ASIA) impairment scale. Two patients were classified as type 3, and one was classified as type 2 based on the MRI spinal cord classification. Intraoperative neurophysiological monitoring (IONM) was consistently negative throughout the corrective procedure, and intraoperative wake-up tests were normal. The average time to DPND development was 11.8h (range, 4-18h), and all three patients achieved complete recovery of neurological function after undergoing revision surgery. A total of 14 articles involving 31 patients were included in the literature review. The mean time to onset of DPND was found to be 25.2h, and 85.3% (29/34) of patients experienced DPND within the first 48h postoperatively, with the most common initial symptoms being decreased muscle strength and sensation (26 patients, 83.9%). Regarding neurological function recovery, 14 patients were able to reach ASIA grade E, while 14 patients were not able to reach ASIA grade E. Univariate analysis revealed that preoperative diagnosis (p = 0.004), operative duration (p = 0.017), intraoperative osteotomy method (p = 0.033), level of neurological deficit (p = 0.037) and deficit source (p = 0.0358) were significantly associated with neurological outcomes. Furthermore, multivariate regression analysis indicated a strong correlation between preoperative diagnosis (p = 0.003, OR, 68.633; 95% CI 4.299-1095.657) and neurological prognosis. Our findings indicate that spinal cord ischemic injury was a significant factor for patients experiencing DPND and distraction after corrective surgery may be a predisposing factor for spinal cord ischemia. Additionally, it is important to consider the possibility of DPND when limb numbness and decreased muscle strength occur within 48h after corrective scoliosis surgery. Moreover, emergency surgical intervention is highly recommended for DPND caused by mechanical compression factors with a promising prognosis for neurological function, emphasizing the importance of taking into account preoperative orthopedic diagnoses when evaluating the potential for neurological recovery.

Timing of intraoperative neurophysiological monitoring (IONM) recovery and clinical recovery after termination of pediatric spinal deformity surgery due to loss of IONM signals

Background ContextIntraoperative neurophysiological monitoring (IONM) is used to reduce the risk of spinal cord injury during pediatric spinal deformity surgery. Significant reduction and/or loss of IONM signals without immediate recovery may lead the surgeon to acutely abort the case. The timing of when monitorable signals return remains largely unknown. PurposeThe goal of this study was to investigate the correlation between IONM signal loss, clinical examination, and subsequent normalization of IONM signals after aborted pediatric spinal deformity surgery to help determine when it is safe to return to the operating room. Study Design/SettingThis is a multicenter, multidisciplinary, retrospective study of pediatric patients (<18 years old) undergoing spinal deformity surgery whose surgery was aborted due to a significant reduction or loss of IONM potentials. Patient SampleSixty-six patients less than 18 years old who underwent spinal deformity surgery that was aborted due to IONM signal loss were enrolled into the study. Outcome MeasuresIONM data, operative reports, and clinical examinations were investigated to determine the relationship between IONM loss, clinical examination, recovery of IONM signals, and clinical outcome. MethodsInformation regarding patient demographics, deformity type, clinical history, neurologic and ambulation status, operative details, IONM information (eg, quality of loss [SSEPs, MEPs], laterality, any recovery of signals, etc.), intraoperative wake-up test, postoperative neurologic exam, postoperative imaging, and time to return to the operating were all collected. All factors were analyzed and compared with univariate and multivariate analysis using appropriate statistical analysis. ResultsSixty-six patients were enrolled with a median age of 13 years [IQR 11-14], and the most common sex was female (42/66, 63.6%). Most patients had idiopathic scoliosis (33/66, 50%). The most common causes of IONM loss were screw placement (27/66, 40.9%) followed by rod correction (19/66, 28.8%). All patients had either complete bilateral (39/66, 59.0%), partial bilateral (10/66, 15.2%) or unilateral (17/66, 25.8%) MEP loss leading to termination of the case. Overall, when patients were returned to the operating room 2 weeks postoperatively, nearly 75% (40/55) had monitorable IONM signals. Univariate analysis demonstrated that bilateral SSEP loss (p=.019), bilateral SSEP and MEP loss (p=.022) and delayed clinical neurologic recovery (p=.008) were significantly associated with having unmonitorable IONM signals at repeat surgery. Multivariate regression analysis demonstrated that delayed clinical neurologic recovery (> 72 hours) was significantly associated with unmonitorable IONM signals when returned to the operating room (p=.006). All patients ultimately made a full neurologic recovery. ConclusionsIn children whose spinal deformity surgery was aborted due to intraoperative IONM loss, there was a strong correlation between combined intraoperative SSEP/MEP loss, the magnitude of IONM loss, the timing of clinical recovery, and the time of electrophysiological IONM recovery. The highest likelihood of having a prolonged postoperative neurological deficit and undetectable IONM signals upon return to the OR occurs with bilateral complete loss of SSEPs and MEPs.

Definition, Frequency and Risk Factors for Intra-Operative Spinal Cord Injury: A Knowledge Synthesis.

Mixed-methods approach. Intra-operative spinal cord injury (ISCI) is a devastating complication of spinal surgery. Presently, a uniform definition for ISCI does not exist. Consequently, the reported frequency of ISCI and important risk factors vary in the existing literature. To address these gaps in knowledge, a mixed-methods knowledge synthesis was undertaken. A scoping review was conducted to review the definitions used for ISCI and to ascertain the frequency of ISCI. The definition of ISCI underwent formal review, revision and voting by the Guidelines Development Group (GDG). A systematic review of the literature was conducted to determine the risk factors for ISCI. Based on this systematic review and GDG input, a table was created to summarize the factors deemed to increase the risk for ISCI. All reviews were done according to PRISMA standards and were registered on PROSPERO. The frequency of ISCI ranged from 0 to 61%. Older age, male sex, cardiovascular disease including hypertension, severe myelopathy, blood loss, requirement for osteotomy, coronal deformity angular ratio, and curve magnitude were associated with an increased risk of ISCI. Better pre-operative neurological status and use of intra-operative neuromonitoring (IONM) were associated with a decreased risk of ISCI. The risk factors for ISCI included a rigid thoracic curve with high deformity angular ratio, revision congenital deformity with significant cord compression and myelopathy, extrinsic intradural or extradural lesions with cord compression and myelopathy, intramedullary spinal cord tumor, unstable spine fractures (bilateral facet dislocation and disc herniation), extension distraction injury with ankylosing spondylitis, ossification of posterior longitudinal ligament (OPLL) with severe cord compression, and moderate to severe myelopathy. ISCI has been defined as "a new or worsening neurological deficit attributable to spinal cord dysfunction during spine surgery that is diagnosed intra-operatively via neurophysiologic monitoring or by an intraoperative wake-up test, or immediately post-operatively based on clinical assessment". This paper defines clinical and imaging factors which increase the risk for ISCI and that could assist clinicians in decision making.

Negative pressure suction test: An intraoperative airway maneuver to assess effectiveness of surgical correction of tracheobronchomalacia.

Surgical correction of tracheobronchomalacia (TBM) has evolved greatly over the past decade, with select pediatric institutions establishing dedicated surgery and anesthesia teams to navigate the complexities and challenges of surgical airway repairs. Although anesthetic techniques have evolved internally over many years to improve patient safety and outcomes, many of these methods remain undescribed in literature. In this article, we describe the intraoperative negative pressure suction test. This simulates the negative pressure seen in awake and spontaneously breathing patients, including the higher pressures seen during coughing which induce airway collapse in patients with TBM. Also known as the Munoz maneuver in surgical literature, this test has been performed on over 300 patients since 2015. The negative pressure suction test allows for controlled intraoperative assessment of surgical airway repairs, replaces the need for risky intraoperative wake-up tests, increases the chances of a successful surgical repair, and improves anesthetic management for emergence and extubation. We provide a guide on how to perform the test and videos demonstrating its efficacy in intraoperative airway evaluation. As surgeries to repair TBM become more prevalent in other pediatric institutions, we believe that pediatric patients and anesthesia providers will benefit from the insights and methods described here.

The effect of dexmedetomidine on wake-up test quality when muscle relaxants are not used: A randomized control trial.

Stagnara wake-up test is a simple reproducible neuromonitoring method during spinal surgery which replaces the evoked potential monitoring in the absence of neuromonitoring facilities. Dexmedetomidine (DEX) effect on the intraoperative wake-up test is still unclear. The present study was conducted to evaluate the effectiveness of DEX on the quality of wake-up test during spinal correction surgery. A randomized controlled study was carried out over 62 patients randomized into two equal groups planned for elective minimally invasive corrective spine surgery. Instead of atracurium administration in the control group, patients in the experimental group were administered titrated continuous intravenous infusion of DEX at a dose of 0.2-0.7 μg/kg/hour. Lidocaine 2% spray around the vocal cords was done in both the groups to facilitate toleration of the endotracheal tube. The DEX group showed statistically significant longer duration and better quality of the wake-up test. Statistically significant better haemodynamic state, a lower amount of intraoperative sedatives and higher amount of intraoperative analgesics were also evident in the DEX group. The postoperative Ramsay sedation scale was significantly lower in the DEX group just after extubation. The DEX use has shown an improving effect on the wake-up test quality, with slightly prolonged wake-up time. The present work supports the use of DEX as an adjuvant drug alleviating the need for the neuromuscular blockade, inducing a better haemodynamic profile, exhibiting better sedation and improving the awakening condition.

Deformity angular ratio is associated with neuromonitoring changes without a vertebral column resection: spinal deformity is more influential than type of surgery

PurposeThe purpose of this study is to investigate the effect of the deformity angular ratio (DAR) on intra-operative neuromonitoring (IONM) signal changes during posterior spinal fusion (PSF) without vertebral column resection (VCR).MethodsRetrospective review of severe pediatric spinal deformity patients treated with PSF without VCR or three-column osteotomy from 2008 to 2018. Exclusion criteria were prior instrumentation, lack of IONM, and incomplete radiographic data. Coronal DAR (C-DAR), sagittal DAR (S-DAR), and total DAR (T-DAR) were calculated and compared between patients with IONM signal loss and those without.ResultsTwo hundred and fifty-three patients met inclusion criteria. Forty-seven of two hundred and fifty-three (19%) patients had IONM signal loss. Intra-operative wake-up test was performed in seven cases; three of seven (43%) had a neurological deficit on wake-up test. All neurological deficits resolved at a mean of 41 days postop. IONM loss was associated with increased kyphosis (p = 0.003) and was not associated with Cobb angle (p = 0.16). S-DAR (p = 0.03) and T-DAR (p = 0.005) were associated with IONM signal loss but C-DAR was not (p = 0.06). Increased incidence of IONM signal loss was seen with S-DAR > 7 (p = 0.02) or T-DAR > 27 (p = 0.02). Twenty-four of ninety-two (26%) patients with S-DAR > 7 had IONM signal loss compared to twenty-three of one hundred and sixty-one (14%) with S-DAR ≤ 7 (OR, 2.1; 95% CI, 1.1–4.0). Seven of sixteen (44%) patients with T-DAR > 27 had signal loss compared to forty of two hundred and thirty-seven (17%) patients with T-DAR ≤ 27 (OR, 3.8; 95% CI, 1.3–10.9).ConclusionPatients with S-DAR > 7 or T-DAR > 27 have a higher risk of IONM loss during pediatric PSF even in the absence of a VCR or three-column osteotomies.Level of evidence II.

Dexmedetomidine dosage in critically ill patients undergoing intraoperative wake-up test

Objective:The aim of this study was to find the optimum dosage of dexmedetomidine in Spinal Orthopedic Scoliosis Correction Surgery when used in combination with propofol and remifentanil in American Society of Anesthesiologists (ASA) III patients with severe scoliosis undergoing intraoperative wake-up test.Materials and methods:We selected a total of 60 ASA III ≤40 years old patients who underwent Spinal Orthopedic Scoliosis Correction Surgery (SOSCS) and randomized them into groups A, B, and C. Group A was administered 0.2 μg/(kg·h) of dexmedetomidine, group B 0.3 μg/(kg·h), and group C 0.4 μg/(kg·h). The main parameters monitored were: wake-up time; wake-up quality; adverse effects that occur while the patient is awake; postoperative awareness of intraoperative wake-up test; heart rate (HR); mean arterial pressure (MAP); and oxygen saturation (SpO2). Values of these parameters were monitored at 7 timestamps separated by 5 minutes >30 minutes.Results:Group B had a higher MAP at 10 minutes before wake-up (P = .03) and at the moment of wake-up (P = .04) than group A. The Wake-up time of group A was 14.95 ± 7.42 minutes, group B was 14.7 ± 6.52 minutes, which was significantly shorter than that of group C 21.3 ± 10.02 minutes (P = .02). The wake-up quality was excellent. All other parameters had no significant statistical differences.Conclusion:Doses of 0.2 to 0.3 μg/(kg·h) have shorter wake-up time and fewer hemodynamic fluctuations compared to 0.4 μg/(kg·h).

Effect Of Dexmedetomidine On Intraoperative Wake-Up Test During Spinal Surgery: A Meta-Analysis Of Randomized Controlled Trials

The safety and effectiveness of Dexmedetomidine (DEX) for intraoperative wake-up test are still controversial. The meta-analysis was performed to evaluate the safety and effectiveness of DEX for intraoperative wake-up test during spinal surgery.

Effectiveness of dexmedetomidine for intraoperative wake-up test during spinal surgery: a meta-analysis of randomized placebo-controlled clinical trials

Objective To explore the safety and effectiveness of dexmedetomidine in intraoperative wake-up during spinal surgery. Methods We searched PubMed, EMbase, Web of Science, Chinese biomedical database (CBM) and China national knowledge infrastructure (CNKI) for clinical randomized controlled trials about the effects of dexmedetomidine on intraoperative wake-up during spinal surgery. RevMan 5.3 software was used for Meta analysis of the included studies. Results Fourteen randomized controlled trials involving 696 patients were included in the Meta-analysis study. The patients were divided into two groups: a dexmedetomidine group (n=348) and a control group (n=348). Results showed that no significant difference in wake-up time was found between two groups [mean deviation (MD)=0.18, 95%CI:-0.27-0.36, P=0.44]. However, compared with the control group, the dexmedetomidine group presented substantially improvement in wake-up quality [relative risk (RR)=2.02, 95%CI: 1.58-2.68, P<0.001. RR=1.69, 95%CI: 1.30-2.21, P<0.001], and lower MAP and HR levels at wake-up time (MD=-13.39, 95%CI: -18.20-8.58, P<0.01. MD=-14.53, 95%CI: -17.44-11.61, P<0.01]. Conclusions Dexmedetomidine can not prolong wake-up time and may contribute to improvement in wake-up quality and maintain hemodynamic stability during wake-up period in spinal surgery. However, due to the existence of various biases, more high quality studies are needed to confirm the results. Key words: Dexmedetomidine; Spinal surgery; Wake-up; Meta-analysis

Population pharmacokinetic-pharmacodynamic model of propofol in adolescents undergoing scoliosis surgery with intraoperative wake-up test: a study using Bispectral index and composite auditory evoked potentials as pharmacodynamic endpoints

BackgroundIn adolescents limited data are available on the pharmacokinetics (PK) and pharmacodynamics (PD) of propofol. In this study we derived a PK-PD model for propofol in adolescents undergoing idiopathic scoliosis surgery with an intraoperative wake-up test with reinduction of anesthesia using both Bispectral Index (BIS) and composite A-line ARX index (cAAI) as endpoints.MethodsFourteen adolescents (9.8–20.1 years) were evaluated during standardized propofol-remifentanil anesthesia for idiopathic scoliosis surgery with an intraoperative wake-up test with reinduction of anesthesia. BIS and cAAI were continuously measured and blood samples collected. A propofol PKPD model was developed using NONMEM.ResultsThe time courses of propofol concentrations, BIS and cAAI values during anesthesia, intra-operative wakeup and reduction of anesthesia were best described by a two-compartment PK model linked to an inhibitory sigmoidal Emax PD model. For the sigmoidal Emax model, the propofol concentration at half maximum effect (EC50) was 3.51 and 2.14 mg/L and Hill coefficient 1.43 and 6.85 for BIS and cAAI, respectively. The delay in PD effect in relation to plasma concentration was best described by a two compartment effect-site model with a keo of 0.102 min− 1, ke12 of 0.121 min− 1 and ke21 of 0.172 min− 1.ConclusionsA population PKPD model for propofol in adolescents was developed that successfully described the time course of propofol concentration, BIS and cAAI in individuals upon undergoing scoliosis surgery with intraoperative wake-up test and reinduction of anesthesia. Large differences were demonstrated between both monitors. This may imply that BIS and cAAI measure fundamentally different endpoints in the brain.

Simultaneous Surgical Treatment of Congenital Spinal Deformity Associated with Intraspinal Anomalies.

Study DesignProspective case series.PurposeTo study the safety, efficacy, and long-term outcomes of single-stage surgical intervention for congenital spinal deformity and intraspinal anomalies.Overview of literatureCongenital spinal deformities associated with intraspinal anomalies are usually treated sequentially, first by treating the intraspinal anomalies followed by deformity correction after a period of 3–6 months. Recently, a single-stage approach has been reported to show better postoperative results and reduced complication rates.MethodsThirty patients (23 females and seven males) were prospectively evaluated for the simultaneous surgical treatment of congenital spinal deformity with concurrent intraspinal anomalies from May 2006 to October 2016. The average age at presentation was 9.8±3.7 years, with the average follow-up duration being 49.06±8.6 months. Clinical records were evaluated for clinical, radiological, perioperative, and postoperative data.ResultsThe average angle of deformity was 56.53°±25.22° preoperatively, 21.13°±14.34° postoperatively, and 23.93°±14.99° at the final follow-up. The average surgical time was 232.58±53.56 minutes (range, 100–330 minutes), with a mean blood loss of 1,587.09±439.09 mL (range, 100–2,300 mL).ConclusionsSingle stage surgical intervention for intraspinal anomalies with congenital spinal deformity correction, including adequate intra-operative wake-up test, is a viable option in appropriately selected patients and has minimum complication rates.

Comparison of intraoperative wake-up test performed under different methods of anesthesia in patients undergoing scoliosis correction

Objective To compare the intraoperative wake-up test performed under different methods of anesthesia in the patients undergoing scoliosis correction. Methods Sixty American Society of Anesthesiologists physical status Ⅰ or Ⅱ patients of both sexes, aged 14-35 yr, undergoing elective scoliosis correction, were divided into dexmedetomidine-based anesthesia group(D group)and sevoflurane-based anesthesia group(S group), with 30 cases in each group.Patients were tracheally intubated after induction of anesthesia.Maintenance of anesthesia was as follows: remifentanil 0.3 μg·kg-1·min-1 was intravenously infused, dexmedetomidine 0.2 μg·kg-1·h-1 was intravenously infused in group D, and group S inhaled low flow sevoflurane 1 L/min with the end-tidal concentration of 0.8%-1.5%.Narcotrend index value was maintained at 30-45.The wake-up time, adverse events, requirement for vasoactive agents and blood loss during wake-up test were recorded.The wake-up quality was evaluated. Results All the patients successfully completed wake-up tests.Compared with group S, the wake-up quality was significantly increased, the incidence of agitation and bucking was decreased during wake-up test, the blood loss was reduced during wake-up test(P 0.05). Conclusion Dexmedetomidine-based anesthesia produces better efficacy for intraoperative wake-up test than sevoflurane-based anesthesia in the patients undergoing scoliosis correction. Key words: Dexmedetomidine; Anesthetics, inhalation; Scoliosis; Wake-up test

Effect of dexmedetomidine on quality of intraoperative wake-up test in patients undergoing balloon occlusion test of the internal carotid artery

Objective To evaluate the effect of dexmedetomidine on the quality of intraoperative wake-up test in the patients undergoing balloon occlusion test of the internal carotid artery. Methods Forty-two patients of either sex with intracranial aneurysm, aged 57-78 yr, weighing 53-86 kg, of American Society of Anesthesiologists physical status Ⅱ or Ⅲ, scheduled for elective balloon occlusion test of the internal carotid artery under general anesthesia, were assigned into 2 groups(n=21 each)using a random number table: propofol combined with remifentanil group(group PR)and dexmedetomidine combined with propofol and remifentanil group(group DPR). In group DPR, dexmedetomidine was intravenously infused over 15 min in a loading dose of 0.5μg·kg-1 before induction of anesthesia, followed by an infusion of 0.3 μg·kg-1·h-1 throughout surgery.Propofol and remifentanil were given by target-controlled infusion(TCI)after infusion of the loading dose.The patients were mechanically ventilated after placement of the laryngeal mask airway.Maintenance of anesthesia was as follows: propofol and remifentanil were given by TCI with the target plasma concentrations of 0.5-1.0 μg/ml and 1-3 ng/ml, respectively, in group DPR; propofol and remifentanil were given by TCI with the target plasma concentrations of 3-5 μg/ml and 3-6 ng/ml, respectively, in group PR.Bispectral index(BIS)value was maintained at 40-60.Before wake-up test, propofol infusion was stopped and the target plasma concentration of remifentanil was decreased to 0.5 ng/ml in two groups, and the infusion rate of dexmedetomidine was decreased to 0.1 μg·kg-1·h-1 in group DPR.The wake-up time was recorded and the wake-up quality was assessed.After admission to the operating room(T0, baseline), at 10 min before wake-up test(T1), immediately after patients were wakened(T2), at 10 min after patients were wakened(T3)and at the end of wake-up test(T4), the mean blood pressure(MAP), heart rate, respiratory rate(RR), SpO2 and BIS values were recorded.The development of intraoperative awareness, emergence time, postoperative agitation, nausea and vomiting, regurgitation and aspiration and severe pain was recorded. Results MAP, heart rate, SpO2 and RR were all within the normal range during wake-up period in two groups.Compared with the baseline at T0, MAP was significantly decreased at T1, 3, 4 in group PR, and BIS value was decreased at T1-4 in DPR and PR groups(P 0.05). No cardiovascular events, respiratory depression, intraoperative awareness, postoperative nausea and vomiting, regurgitation and aspiration or severe pain was found in two groups. Conclusion Dexmedetomidine can raise the quality of intraoperative wake-up test in the patients undergoing balloon occlusion test of the internal carotid artery. Key words: Dexmedetomidine; Monitoring, intraoperative; Carotid artery, internal; Embolization, therapeutic; Wake-up test

Impact of Dexmedetomidine on Intraoperative Wake-Up Tests in Patients Undergoing Spinal Surgery

To evaluate the impact of dexmedetomidine (DEX) on intraoperative wake-up tests. American Society of Anesthesiologists category I or II patients were divided into two groups: a propofol-remifentanil group (group R, n = 20) and a DEX-propofol-remifentanil group (group D, n = 20). The patients in group D received DEX, whereas the patients in group R received the same volume of saline. The other anesthetic methods and drugs (propofol and remifentanil) were the same in both groups. During the wake-up test, patients were repeatedly asked to move their fingers. All the wake-up tests were successfully performed. There was no significant difference in the mean wake-up time between the two groups. Eighteen patients exhibited better wake-up quality in group D as did eight patients in group R. The patients in group D had a significantly better overall wake-up quality than those in group R (P <.05). DEX did not affect the wake-up time and increased the wake-up quality.

Posterior-only surgical correction of adolescent idiopathic scoliosis: an Egyptian experience.

Introduction: The aim of this prospective case series study is to document safety and effectiveness of high density pedicle screws through posterior only approach with intraoperative wake-up test in correction of adolescent idiopathic scoliosis (AIS).Methods: Between 2011 and 2015, all surgically treated patients for AIS were followed up for a minimum of 2 years. Clinical outcomes were evaluated using scoliosis research society-22 (SRS) questionnaire. All patients were classified according to Lenke classification. Major and minor curves Cobb angle as well as sagittal parameters were measured on whole spine X-rays. All patients underwent an intra-operative wake-up test after deformity correction and a minimum of 80% metal density of implants was used.Results: This study included 50 patients. The mean age at time of surgery was 16.8 years. The mean follow-up period was 38.1 months. The mean correction rate for the coronal Cobb angle of the major curve was 79.12%, while that of the minor curve was 68.9%. The mean thoracic kyphosis angle was 38.4° preoperatively, 29.76° postoperatively and 30.36° at the last follow-up. The mean SRS-22 questionnaire scores improved significantly at the last follow-up (P > 0.001). There were no neurological deficits at the wake-up test. No cases of pseudarthrosis or metal failure were encountered.Conclusion: This is a prospective study of at least 80% metal density pedicle screws technique and intra-operative wake-up test in Egyptian patients with AIS. It proved to be an effective and safe technique in correction of radiological parameters, with no neurological or implant related complications. It allowed excellent scoliotic and kyphotic curves correction with minimal loss of correction. On the whole it led to better quality of life.

Benefit of general anesthesia monitored by bispectral index compared with monitoring guided only by clinical parameters. Systematic review and meta-analysis

The bispectral index parameter is used to guide the titration of general anesthesia; however, many studies have shown conflicting results regarding the benefits of bispectral index monitoring. The objective of this systematic review with meta-analysis is to evaluate the clinical impact of monitoring with the bispectral index parameter. The search for evidence in scientific information sources was conducted during December 2013 to January 2015, the following primary databases: Medline/PubMed, LILACS, Cochrane, CINAHL, Ovid, SCOPUS and TESES. The criteria for inclusion in the study were randomized controlled trials, comparing general anesthesia monitored, with bispectral index parameter with anesthesia guided solely by clinical parameters, and patients aged over 18 years. The criteria for exclusion were studies involving anesthesia or sedation for diagnostic procedures, and intraoperative wake-up test for surgery of the spine. The use of monitoring with the bispectral index has shown benefits reducing time to extubation, orientation in time and place, and discharge from both the operating room and post anesthetic care unit. The risk of nausea and vomiting after surgery was reduced by 12% in patients monitored with bispectral index. Occurred a reduction of 3% in the risk of cognitive impairment postoperatively at 3 months postoperatively and 6% reduction in the risk of postoperative delirium in patients monitored with bispectral index. Furthermore, the risk of intraoperative memory has been reduced by 1%. Clinically, anesthesia monitoring with the BIS can be justified because it allows advantages from reducing the recovery time after waking, mainly by reducing the administration of general anesthetics as well as the risk of adverse events.

Benefit of general anesthesia monitored by bispectral index compared with monitoring guided only by clinical parameters. Systematic review and meta-analysis

BackgroundThe bispectral index parameter is used to guide the titration of general anesthesia; however, many studies have shown conflicting results regarding the benefits of bispectral index monitoring. The objective of this systematic review with meta-analysis is to evaluate the clinical impact of monitoring with the bispectral index parameter. MethodsThe search for evidence in scientific information sources was conducted during December 2013 to January 2015, the following primary databases: Medline/PubMed, LILACS, Cochrane, CINAHL, Ovid, SCOPUS and TESES. The criteria for inclusion in the study were randomized controlled trials, comparing general anesthesia monitored, with bispectral index parameter with anesthesia guided solely by clinical parameters, and patients aged over 18 years. The criteria for exclusion were studies involving anesthesia or sedation for diagnostic procedures, and intraoperative wake-up test for surgery of the spine. ResultsThe use of monitoring with the bispectral index has shown benefits reducing time to extubation, orientation in time and place, and discharge from both the operating room and post anesthetic care unit. The risk of nausea and vomiting after surgery was reduced by 12% in patients monitored with bispectral index. Occurred a reduction of 3% in the risk of cognitive impairment postoperatively at 3 months postoperatively and 6% reduction in the risk of postoperative delirium in patients monitored with bispectral index. Furthermore, the risk of intraoperative memory has been reduced by 1%. ConclusionClinically, anesthesia monitoring with the BIS can be justified because it allows advantages from reducing the recovery time after waking, mainly by reducing the administration of general anesthetics as well as the risk of adverse events.

Significant Alerts in Intraoperative Neurophysiologic Monitoring during Severe Spinal Deformity Surgeries- A Categorical Description Experience in Tertiary Care Referral Center from the Subcontinent

Introduction Intraoperative Neurophysiological monitoring (IONM) has become a standard of care in spinal deformity surgeries to minimize the incidence of new onset neurological deficit. It has largely averted the use of historic intraoperative wake-up test. The risk of new neurologic deficit, in such cases, is high and frequency of significant alerts in neuro-monitoring can distress the surgeon so it is essential for the surgeon to know about the various categories of alerts and their management. Study Design Retrospective review of all spinal deformity surgeries performed with IONM in an Indian hospital over a period from 2011–2015. Material and Methods All except two patients were subjected to IONM by transcranial electrical motor evolked potentials (TCeMEP) during the spinal deformity surgery. These two patients were monitored with SSEP. Patients were included in the study only if complete demographic data, operative reports and neuromonitoring data and post-operative neurological data were available for review. A significant IONM alert during MEP monitoring was defined as 80% or more decrement in the MEP amplitude, or Increase in threshold of 100 V or more from baseline. During SSEP monitoring, significant alert was defined as 50% or greater decrease from baseline in the amplitude or latency prolongation by 10% or more. A full neurologic recovery was defined as a return to baseline for all MEP and SSEP signals. The systemic and surgical causes of IONM alerts and the postoperative neurological status were recorded. Results Total 43 patients underwent the surgery for severe spinal deformities with neuromonitoring. The average age was 13.2 years (6–38), and male:female ratio was 11:32. Diagnoses included idiopathic scoliosis (26), congenital scoliosis (6), congenital kyphosis (5), congenital kyphoscoliosis (2), post-infectious kyphosis (3), and post-traumatic kyphosis (1). The average kyphosis was 84; (45–136); the average scoliosis was 89; (62–128). There were total 21 IONM alerts in 16 patients (37%). The most common causes were Hypotension (5), drug induced (4), distraction (4), deformity correction (3), SPO/Ponte/PSO osteotomies (2), Tachycardia (2) and Screw placement (1). Reversal of the inciting cause resulted in complete reversal of the alert in 90% of the times. Two patients wake up with neurodeficit (Screw placement and deformity correction) which recovered over few weeks. One patient showed persistent alerts but wake up without any deficit. Conclusion IONM alerts are frequent during severe spinal deformity surgery. In our study more than 50% of the alerts were associated with anesthetic management (hypotension, drugs and tachycardia). So in case of significant alert, surgeon should not get stressed out but to analyze whether the cause is systemic and the first step is to maintain the mean blood pressure. However, the most common cause of persistent IONM alert were screw malposition and deformity correction. Careful surgical technique supported by IONM and their interpretation can reduce neurologic mishaps.

Application of awaking anesthesia with laryngeal mask airway in strabismus surgery

Objective To evaluate the feasibility of the intraoperative wake-up test in strabismus surgery anaesthetized with laryngeal mask airway (LMA). Methods A total of 169 strabismus patients were randomly divided into 2 groups. The first group had general anesthesia with intraoperative wake-up test and the other group without the test. In the first group, operated muscles were first tightened with a slipknot. Then, the patient was awakened to examine the eye position. If the position was orthoptic, finish up the operation. Otherwise, general anesthesia with LMA was reinstalled and the surgical procedures were repeated until the orthoptic position was achieved.The patients who did not receive intraoperative wake-up test underwent surgery according to the preoperative assessment. Results Among 87 patients in the group with intraoperative wake-up test, three of them were not cooperative after awaking and were abandoned. All 82 patients in the group without intraoperative wake-up test finished surgeries successfully. The success rate of the group with intraoperative wake-up test was 98.85% one week after the operation, which was significantly higher than that 91.46% in the other group (P=0.030). One year after the operation, the success rates of surgery in patients with and without intraoperative wake-up test were 95.4% and 85.37% respectively. There was statistically significant difference between two groups (P=0.035). Conclusion Awaking anesthesia with LMA is safe and effective in strabismus surgery, which can improve the success rate. The patients could tolerate the LMA and complete the adjustment of eye position successfully. Key words: Surgery, strabismus; Anesthesia, awaking; Airway, mask, laryngeal

Wake-up test in total hip arthroplasty with high-riding developmental dysplasia.

Total hip arthroplasty (THA) for patients with Crowe type IV developmental dysplasia of the hip is technically challenging. This group of patients has a higher incidence of nerve injury during THA. Although neurophysiologic intraoperative monitoring has been developed to provide nerve monitoring, it is not always available. The wake-up test has been used for intraoperative spinal cord monitoring during major spinal surgery, but no study has reported the use of the wake-up test for neurologic monitoring during THA in patients with severe developmental dysplasia of the hip. The authors retrospectively reviewed 22 THA procedures in 20 patients with Crowe type IV developmental dysplasia of the hip who underwent the wakeup test during THA. In the current study, 1 patient could not dorsiflex her foot during the wake-up test. Therefore, the authors immediately reduced the length of limb lengthening by 1 cm. Postoperative drop foot and numbness occurred but resolved completely 2 months later. None of the patients who showed no deficits in motion of the feet during the intraoperative wake-up test had signs of postoperative nerve injury. In the current study, there was no false-positive or false-negative finding. The authors concluded that the wake-up test, which is simple, safe, and reliable, is a useful technique and a possible alternative to neurophysiologic intraoperative monitoring in checking nerve function during THA in patients with severe developmental dysplasia of the hip.