Intraoperative mechanical power and postoperative pulmonary complications in low-risk surgical patients: a prospective observational cohort study.

BACKGROUND: Inadequate intraoperative mechanical ventilation (MV) can lead to ventilator-induced lung injury and increased risk for postoperative pulmonary complications (PPCs). Mechanical power (MP) was shown to be a valuable indicator for MV outcomes in critical care patients. The aim of this study is to assess the association between intraoperative MP in low-risk surgical patients undergoing general anesthesia and PPCs. METHODS: Two-hundred eighteen low-risk surgical patients undergoing general anesthesia for elective surgery were included in the study. Intraoperative mechanical ventilatory support parameters were collected for all patients. Postoperatively, patients were followed throughout their hospital stay and up to seven days post discharge for the occurrence of any PPCs. RESULTS: Out of 218 patients, 35% exhibited PPCs. The average body mass index, tidal volume per ideal body weight, peak inspiratory pressure, and MP were significantly higher in the patients with PPCs than in the patients without PPCs (30.3 ± 8.1 kg/m2 vs. 26.8 ± 4.9 kg.m2, p < 0.001; 9.1 ± 1.9 ml/kg vs. 8.6 ± 1.4 ml/kg, p = 0.02; 20 ± 4.9 cmH2O vs. 18 ± 3.7 cmH2O, p = 0.001; 12.9 ± 4.5 J/min vs. 11.1 ± 3.7 J/min, p = 0.002). A multivariable regression analysis revealed MP as the sole significant predictor for the risk of postoperative pulmonary complications [OR 1.1 (95% CI 1.0-1.2, p = 0.036]. CONCLUSIONS: High intraoperative mechanical power is a risk factor for developing postoperative pulmonary complications. Furthermore, intraoperative mechanical power is superior to other traditional mechanical ventilation variables in identifying surgical patients who are at risk for developing postoperative pulmonary complications. CLINICAL TRIAL REGISTRATION: NCT03551899; 24/02/2017.

The effect of the addition of nefopam to intraoperative ketoprofen and acetaminophen on postoperative morphine requirements after laparoscopic cholecystectomy: a randomized controlled trial.

BACKGROUND: Few studies investigated the use of nefopam for pain control after laparoscopic cholecystectomy in the context of multimodal analgesia. The aim of this study was to evaluate the effect of adding nefopam to ketoprofen and acetaminophen given before the end of laparoscopic cholecystectomy. METHODS: In this double-blind, controlled study, 90 patients undergoing laparoscopic cholecystectomy during sevoflurane-dexmedetomidine-based anesthesia were randomized to receive either ketoprofen and acetaminophen or nefopam, ketoprofen, and acetaminophen for postoperative pain control before the end of surgery. The primary outcome was total morphine consumption in the Postanesthesia Care Unit (PACU). RESULTS: PACU morphine consumption was significantly lower in the experimental group compared to the control group (0.9±1.8 mg vs. 2.3±2.4 mg, respectively; P=0.004, Cohen's d=0.63). In the experimental group, a smaller proportion of patients received morphine in PACU (24% vs. 60%, respectively; P=0.001), morphine during the first 24 hours after surgery (47% vs. 77%, respectively; P=0.004), and acetaminophen on the floor (76% vs. 93%, respectively; P=0.039) compared with the control group. The average pain score during PACU stay was also significantly lower in the experimental group (1.7±2.0 vs. 2.7±2.0, P=0.01). Median time to first morphine requirement (44.0 minutes, 95% CI [(31.96 to, 52.21)] was shorter in the control group than in the experimental group (higher than the 90 minutes-last time point taken in PACU). CONCLUSIONS: Adding nefopam to ketoprofen and acetaminophen before the end of laparoscopic cholecystectomy provides a reduction in morphine consumption with superior analgesia in PACU.

Harlequin syndrome during peripheral cardiopulmonary bypass in a patient with an obstructing tracheal schwannoma: A case report.

Surgical resection of obstructive tracheal tumors can be challenging to cardiothoracic surgeons and anesthesiologists. It is often difficult in these cases to maintain oxygenation by face mask ventilation during induction of general anesthesia. Also, the extent and location of these tracheal tumors can preclude conventional induction of general anesthesia and subsequent successful endotracheal intubation. Peripheral cardiopulmonary bypass (CPB) under local anesthesia and mild intravenous sedation may be safe to support the patient until securing a definitive airway. We describe a case of a 19-year-old female with a tracheal schwannoma, who developed differential hypoxemia (Harlequin, or North-South, syndrome) after institution of awake peripheral femorofemoral venoarterial (VA) partial CBP.

Respiratory Adverse Events After LMA® Mask Removal in Children: A Randomized Trial Comparing Propofol to Sevoflurane.

BACKGROUND: The removal of the laryngeal mask airway (LMA®) in children may be associated with respiratory adverse events. The rate of occurrence of these adverse events may be influenced by the type of anesthesia. Studies comparing total intravenous anesthesia (TIVA) with propofol and sevoflurane are limited with conflicting data whether propofol is associated with a lower incidence of respiratory events upon removal of LMA as compared to induction and maintenance with sevoflurane. We hypothesized that TIVA with propofol is superior to sevoflurane in providing optimal conditions and improved patient's safety during emergence. METHODS: In this prospective, randomized, double-blind clinical trial, children aged 6 months to 7 years old were enrolled in 1 of 2 groups: the TIVA group and the sevoflurane group. In both groups, patients were mechanically ventilated. At the end of the procedure, LMAs were removed when patients were physiologically and neurologically recovered to a degree to permit a safe, natural airway. The primary aim of this study was to compare the occurrence of at least 1 respiratory adverse event, the prevalence of individual respiratory adverse events, and the airway hyperreactivity score following emergence from anesthesia between the 2 groups. Secondary outcomes included ease of LMA insertion, quality of anesthesia during the maintenance phase, hemodynamic stability, time to LMA removal, and incidence of emergence agitation. RESULTS: Children receiving TIVA with propofol had a significantly lower incidence (10.8.% vs 36.2%; relative risk, 0.29; 95% CI [0.14-0.64]; P = .001) and lower severity ( P = .01) of respiratory adverse outcomes compared to the patients receiving inhalational anesthesia with sevoflurane. There were no statistically significant differences in secondary outcomes between the 2 groups, except for emergence agitation that occurred more frequently in patients receiving sevoflurane ( P < .001). CONCLUSIONS: Propofol induction and maintenance exerted a protective effect on healthy children with minimal risk factors for developing perioperative respiratory complications, as compared to sevoflurane.

A sequential allocation study to determine the ED50 of Dexmedetomidine as an adjuvant to lidocaine intravenous regional anesthesia.

BACKGROUND: Intravenous regional anesthesia is an easy and reliable anesthetic technique, but its use is limited by tourniquet pain. Clonidine is effective in overcoming this shortcoming when used with intravenous regional anesthesia at a dose of 1 µg/kg. Dexmedetomidine has also been used successfully at a dose of 0.5 µg/kg. OBJECTIVE: Based on the potency ratios of clonidine and dexmedetomidine (8 to 1) we hypothesize that a lower dexmedetomidine dose would provide patients with 50 min of pain free tourniquet time. METHODS: After informed consent, patients received intravenous regional anesthesia with lidocaine and dexmedetomidine following a sequential allocation scheme. The first patient received a dose of 0.5 µg/kg of dexmedetomidine. The dose was then adjusted in 0.1 µg/kg gradients for the following patients depending on the success of the previous block. If a patient experienced tourniquet pain prior to 50 min, the next patient received a higher dose. If not, the dose was decreased. Recruitment continued until 6 independent crossovers were observed with a minimum of 20 patients. The median effective dose ED50 of dexmedetomidine was calculated using the modified up-and-down method. MAIN OUTCOME MEASURES: The median effective dose of dexmedetomidine (ED50) that provides 50 min of tolerance to the tourniquet during a lidocaine intravenous regional anesthesia by a sequential Dixon up-and-down allocation study. RESULTS: The ED50 of dexmedetomidine that provided 50 min of tolerance to the tourniquet was 0.30 ± 0.06 µg/kg. CONCLUSION: We determined that the dexmedetomidine dose necessary to provide 50 min of pain free tourniquet time during intravenous regional anesthesia was higher than expected based on the relative alpha-2 adrenergic receptor selectivity of dexmedetomidine compared to clonidine. TRIAL REGISTRATION: Clinicaltrials.gov: Retrospectively registered ( NCT05342870 ; registration date: 25/04/2022).

Predictors of postoperative pain, opioid consumption, and functionality after arthroscopic shoulder surgery: A prospective observational study.

PURPOSE: This study aims to identify predictors of postoperative pain and opioid consumption after shoulder surgery to help optimize postoperative pain protocols. STUDY DESIGN: Observational cohort study. METHODS: One thirty-four patients undergoing arthroscopic shoulder repair were included. Variables related to the patient, surgery and anesthesia were collected and correlated with postoperative pain intensity, analgesic consumption, and functionality up to 1-month post-surgery. We used mixed-effect linear models to estimate the association of gender, interscalene block (ISB), preoperative shoulder pain, non-steroidal anti-inflammatory drugs (NSAIDs) consumption before surgery, and type of surgery with each of the following outcomes: postoperative pain scores, opioid consumption, and functionality. We further analyzed the data for pain scores and opioid consumption per body weight using the multiple linear regression analysis to demonstrate the aforementioned associations specifically at 1 h, 6 h, 12 h, 24 h, 72 h, 1 week and 1 month after surgery. RESULTS: Omitting the ISB was associated with higher postoperative pain and cumulative opioid consumption over the first 24 h after surgery. Rotator cuff repair and stabilization surgeries were found to be predictive of higher postoperative pain at 24 h, 72 h, and 1 week and lower functionality at 1 week after surgery. Preoperative shoulder pain and NSAIDs consumption were also predictive of postoperative pain and cumulative opioid consumption. CONCLUSION: Omitting a single shot ISB is a strong predictor of postoperative pain and opioid consumption in the early postoperative phase, beyond which the type of surgery, particularly rotator cuff repair and stabilization surgery, emerges as the most important predictor of postoperative pain and functionality.

Outcomes following Craniosynostosis Surgery at a Tertiary Care Center in the Middle East.

BACKGROUND: Despite advancements in craniosynostosis surgery, open surgical approaches remain crucial for the management of infants >6 months of age and in those with complex synostosis. The clinical features of craniosynostosis remain poorly characterized in the Middle East. This study sought to assess the clinical features and outcomes of infants undergoing craniosynostosis surgery at a tertiary care center in Lebanon. METHODS: A retrospective review was performed of all patients who underwent craniosynostosis surgery from December 2006 to December 2018 at the American University of Beirut Medical Center, Lebanon. Clinicodemographic characteristics, complications, and recurrence outcomes were recorded and evaluated using descriptive statistics. RESULTS: Thirty-five infants met the inclusion criteria, with a mean age of 9.0 ± 4.0 months. The most common site of suture involvement was metopic (28.6%), followed by unilateral coronal (25.7%), sagittal (20.0%), bicoronal (8.6%), and multiple sites (17.1%). Five patients (14.3%) had syndromic synostosis. Median estimated blood loss was 200 mL, and median volume of transfused packed red blood cells was 180 mL. Two patients (5.7%) experienced postoperative complications, including postoperative blood transfusion (n = 1)and wire protrusion requiring removal (n = 1). Three patients (8.6%) required reoperation: 2 (5.7%) for resynostosis and 1 for traumatic fracture repair. Caregivers of all patients reported high satisfaction with cosmetic outcomes 4 weeks postoperatively. CONCLUSIONS: With appropriate perioperative precautions, open craniosynostosis surgery can be performed with minimal complications, low recurrence rates, and satisfactory cosmetic outcomes. Additional population-level data are needed to better characterize craniosynostosis patterns and outcomes in the Middle East.

Effect of postoperative Trendelenburg position on shoulder pain after gynecological laparoscopic procedures: a randomized clinical trial.

BACKGROUND: Laparoscopic surgery has become a standard of care for many gynecological surgeries due to its lower morbidity, pain and cost compared to open techniques. Unfortunately, the use of carbon dioxide (CO2) to insufflate the abdomen is the main contributor to post-operative shoulder pain. METHODS: We aim to assess the effect of postoperative Trendelenburg position on shoulder pain after gynecological laparoscopic procedures. We hypothesize that maintaining the patient in Trendelenburg for 24 h postoperatively will significantly decrease postoperative shoulder pain and analgesic consumption. After obtaining written informed consent, 108 patients were prospectively randomized into two groups. In the control group, patients underwent standard gynecologic laparoscopic procedures; then after passive deflation of the pneumoperitoneum at the end of the surgery, the patients were placed in supine head up position in the post anesthesia care unit (PACU) and received our institution's common postoperative care. Patients in the intervention group were subjected to the same maneuver but were positioned in a Trendelenburg position (20 °) once fully awake and cooperative in the PACU and retained this position for the first 24 h. Numerical rating scale (NRS) was used to assess shoulder pain and nausea upon patient arrival to the PACU, at 4, 6, 12 (primary outcome) and 24 h postoperatively. Time to first rescue pain medication, total rescue pain medications and overall satisfaction with pain control were recorded. 101 patients were included in the final data analysis. RESULTS: Both groups were comparable in terms of baseline characteristics. NRS pain scores were significantly lower in the intervention group at 12 h compared to the control group (0 [0-1] versus 5 [1-4], p < 0.001), furthermore improvement in postoperative shoulder pain between time of arrival to PACU (time zero) and 12 h postoperatively was significantly higher in patients allocated to the experimental group compared to the control group. Pain scores were significantly lower in patients allocated to the experimental group versus the control group (0 [0-1] versus 5 [1-4], p < 0.001). CONCLUSION: In conclusion, Trendelenburg position is an easy non-pharmacologic intervention that is beneficial in reducing postoperative shoulder pain following gynecologic laparoscopic surgery. TRIAL REGISTRATION: Retrospectively registered at Clinicaltrials.gov, registration number NCT04129385,  date of registration: June 28, 2019.

Propofol use in children: updates and controversies.

Advantages of propofol use in children may include less airway complications, less emergence agitation, and less postoperative behavioral changes. However, needle phobia and the complexity of total intravenous anesthesia set-up, as well as the pharmacokinetic and pharmacodynamic restrictions may limit the wide use of propofol-based anesthesia in the form of total intravenous anesthesia. Furthermore, pediatric infusion models and monitoring techniques are not fully validated yet. The choice of anesthesia type in children seems to be the result of a complex interplay between many factors related to the patient and the provider as well as logistic and operational factors that contribute to the decision-making process. Propofol has earned its place as a valuable choice in pediatric anesthesia. In addition, propofol and inhalation anesthesia should not be looked at as mutually exclusive; a combination of both may sometimes be the best approach to complex clinical dilemmas.

Preprocedural ultrasound versus landmark techniques for spinal anesthesia performed by novice residents in elderly: a randomized controlled trial.

BACKGROUND: Spinal anesthesia using the midline approach might be technically difficult in geriatric population. We hypothesized that pre-procedural ultrasound (US)-guided paramedian technique and pre-procedural US-guided midline technique would result in a different spinal anesthesia success rate at first attempt when compared with the conventional landmark-guided midline technique in elderly patients. METHODS: In this prospective, randomized, controlled study, one hundred-eighty consenting patients scheduled for elective surgery were randomized into the conventional surface landmark-guided midline technique (group LM), the pre-procedural US-guided paramedian technique (group UP), or the pre-procedural US-guided midline technique (group UM) with 60 patients in each group. All spinal anesthesia were performed by a novice resident. RESULTS: The successful dural puncture rate on first attempt (primary outcome) was higher in groups LM and UM (77 and 73% respectively) than in group UP (42%; P < 0.001). The median number of attempts was lower in groups LM and UM (1 [1] and 1 [1-1.75] respectively) than in group UP (2 [1, 2]; P < 0.001). The median number of passes was lower in groups LM and UM (2 [0.25-3] and 2 [0-4]; respectively) than in group UP (4 [2-7.75]; P < 0.001). The time taken to perform the spinal anesthesia was not different between groups LM and UM (87.24 ± 79.51 s and 116.32 ± 98.12 s, respectively) but shorter than in group UP (154.58 ± 91.51 s; P < 0.001). CONCLUSIONS: A pre-procedural US scan did not improve the ease of midline and paramedian spinal anesthesia as compared to the conventional landmark midline technique when performed by junior residents in elderly population. TRIAL REGISTRATION: Retrospectively registered at Clinicaltrials.gov, registration number NCT02658058, date of registration: January 18, 2016.

Dexmedetomidine for Improved Quality of Emergence From General Anesthesia: A Dose-Finding Study.

BACKGROUND: Dexmedetomidine provides smooth and hemodynamically stable emergence at the expense of hypotension, delayed recovery, and sedation. We investigated the optimal dose of dexmedetomidine for prevention of cough, agitation, hypertension, tachycardia, and shivering, with minimal side effects. METHODS: In this prospective, randomized, double-blind trial, 216 adult patients were randomly assigned to dexmedetomidine 1 µg/kg (D 1), 0.5 µg/kg (D 0.5), 0.25 µg/kg (D 0.25), or control (C). During emergence, cough, agitation, hemodynamic parameters, shivering, time to extubation, and sedation scores were recorded. RESULTS: A total of 190 patients were analyzed. The respective incidences for the groups D 1, D 0.5, and D 0.25 versus group C were 48%, 64%, and 64% vs 84% for cough-corrected P < .003 between groups D 1 and C; 33%, 34%, and 33% vs 72% for agitation-corrected P < .003 between group C and each of the study groups; and 4%, 2%, and 7% vs 22% for shivering-corrected P = .03 and corrected P = .009 between groups D 1 and D 0.5 versus group C, respectively. The percent increase from baseline blood pressure on extubation for the 3 treatment groups was significantly lower than group C. Percent increase in heart rate was lower than control in groups D 1 and D 0.5 but not in group D 0.25. Time to extubation and sedation scores were comparable. However, more hypotension was recorded during the emergence phase in the 3 treatment groups versus group C. CONCLUSIONS: D 1 at the end of surgery provides the best quality of emergence from general anesthesia including the control of cough, agitation, hypertension, tachycardia, and shivering. D 0.5 also controls emergence phenomena but is less effective in controlling cough. The 3 doses do not delay extubation. However, they cause dose-dependent hypotension.

Pre- and Post-therapy Assessment of Clinical Outcomes and White Matter Integrity in Autism Spectrum Disorder: Pilot Study.

Objective: This pilot study aims to identify white matter (WM) tract abnormalities in Autism Spectrum Disorders (ASD) toddlers and pre-schoolers by Diffusion Tensor Imaging (DTI), and to correlate imaging findings with clinical improvement after early interventional and Applied Behavior Analysis (ABA) therapies by Verbal Behavior Milestones Assessment and Placement Program (VB-MAPP). Methods: DTI scans were performed on 17 ASD toddlers/pre-schoolers and seven age-matched controls. Nine ASD patients had follow-up MRI 12 months following early intervention and ABA therapy. VB-MAPP was assessed and compared at diagnosis, 6 and 12 months after therapies. Tract-Based Spatial Statistics (TBSS) was used to measure fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD), and radial (RD) diffusivity. Results: VB-MAPP scores improved at 6 and 12 months after early intervention and ABA therapy compared to scores at baseline. TBSS analysis showed significant FA decrease and/or RD increase in ASD patients before therapy vs. controls in inferior fronto-occipital fasciculi, uncinate fasciculi, left superior fronto-occipital fasciculus, forceps minor, left superior fronto-occipital fasciculus, right superior longitudinal fasciculus, corona radiate bilaterally, and left external capsule. A significantly FA increase in 21 tracts and ROIs is reported in post- vs. pre-therapy DTI analysis. Conclusion: DTI findings highlighted ASD patient WM abnormalities at diagnosis and confirmed the benefits of 12 months of early intervention and ABA therapy on clinical and neuro imaging outcomes.

The Effect of Intraoperative Dexmedetomidine Versus Morphine on Postoperative Morphine Requirements After Laparoscopic Bariatric Surgery.

BACKGROUND: Dexmedetomidine is an α2 receptor agonist with sedative and analgesic properties. During bariatric surgery, its use may reduce postoperative opioid requirements, reduce their side effects, and improve quality of recovery. The aim of this prospective randomized controlled trial was to compare the effect of dexmedetomidine bolus and infusion versus morphine bolus given prior to the end of laparoscopic bariatric surgery. METHODS: Sixty morbidly obese patients (BMI > 40 kg m-2) aged 18 to 60 years, undergoing laparoscopic sleeve gastrectomy, received morphine sulfate (bolus 0.08 mg kg-1 followed by a saline infusion) (group M, n = 30) or dexmedetomidine (loading dose of 1 µg kg-1 followed by 0.5 µg kg-1 h-1) (group D, n = 30) 30 min before the end of surgery. Data collected included morphine consumption in the post-anesthesia care unit (PACU) (primary outcome) and at 24 h, pain intensity, nausea, heart rate, blood pressure, vomiting, sedation, and quality of recovery. RESULTS: There was no significant difference in morphine consumption in the PACU (group D 12.2 ± 5.44 mg, group M 13.28 ± 6.64 mg, P = 0.54) or at 24 h (group D 40.67 ± 24.78 mg, group M 43.28 ± 27.79 mg, P = 0.75); when accounting for intraoperative morphine given group M had significantly higher morphine consumption when compared to group D (23.48 ± 6.22 mg vs. 12.22 ± 5.54 mg, respectively, P < 0.01). Group D patients had more cardiovascular stability. CONCLUSIONS: Dexmedetomidine given prior to end of laparoscopic sleeve gastrectomy provides the same level of postoperative analgesia as morphine with better hemodynamic profile.

The implementation and efficacy of the Northwestern High Risk Spine Protocol.

OBJECTIVE: The aims of this study were to determine the efficacy and feasibility of implementation of the intraoperative component of a high risk spine (HRS) protocol for improving perioperative patient safety in complex spine fusion surgery. METHODS: In this paired availability study, the total number of red blood cell units transfused was used as a surrogate marker for our management protocol efficacy, and the number of protocol violations was used as a surrogate marker for protocol compliance. RESULTS: The 548 patients (284 traditional vs. 264 HRS protocol) were comparable in all demographics, coexisting diseases, preoperative medications, type of surgery, and number of posterior levels instrumented. However, the surgical duration was 70 minutes shorter in the new group (range, 32-108 minutes shorter; P < 0.0001) and the new protocol patients received a median of 1.1 units less of total red blood cell units (range, 0-2.4 units less; P = 0.006). There were only 7 (2.6%) protocol violations in the new protocol group. CONCLUSIONS: The intraoperative component of the HRS protocol, based on two Do-Confirm checklists that focused on 1) organized communication between intraoperative team members and 2) active maintenance of oxygen delivery and hemostasis appears to maintain a safe intraoperative environment and was readily implemented during a 3-year period.

Predicting major adverse cardiac events in spine fusion patients: is the revised cardiac risk index sufficient?

STUDY DESIGN: Observational cohort study. OBJECTIVE: To determine the accuracy of the Revised Cardiac Risk Index (RCRI) in predicting major adverse cardiac events in patients undergoing spine fusion surgery of 3 levels or more. SUMMARY OF BACKGROUND DATA: Preoperative cardiac testing is extensively guided by the RCRI, which was developed and validated in thoracic, abdominal, and orthopedic surgical patients. Because multilevel spine fusion surgery is often associated with major transfusion, we hypothesize that the RCRI may not accurately characterize the risk of cardiovascular morbidity in these patients. METHODS: After institutional review board approval, perioperative data were collected from 547 patients who underwent 3 or more levels of spinal fusion with instrumentation. Postoperative cardiac morbidity was defined as any combination of the following: arrhythmia requiring medical treatment, myocardial infarction (either by electrocardiographic changes or troponin elevation), or the occurrence of demand ischemia. The surgical complexity was categorized as anterior surgery only, posterior cervical and/or thoracic fusion, posterior lumbar fusion, or any surgery that included transpedicular osteotomies. Logistic regression analysis was performed to determine RCRI performance. RESULTS: The RCRI performed no better than chance (area under the curve = 0.54) in identifying the 49 patients (9%) who experienced cardiac morbidity. CONCLUSION: The RCRI did not predict cardiac morbidity in our patients undergoing major spine fusion surgery, despite being extensively validated in low-risk noncardiac surgical patients. Preoperative testing and optimization decisions, previously based on the RCRI, may need to be revised to include more frequent functional cardiac imaging and more aggressive implementation of pharmacologic modalities that may mitigate cardiac morbidity, similar to the preoperative evaluation for major vascular surgery. LEVEL OF EVIDENCE: 3.

Development and validation of a generalizable model for predicting major transfusion during spine fusion surgery.

BACKGROUND: Surgery for posterior spine instrumentation often requires major transfusion. The aim of this study was to develop and test the validity of a model for predicting intraoperative major transfusion (>4 U total red blood cells), based on preoperative patient and surgical variables, that was applicable to adult patients undergoing cervical, thoracic, and/or lumbar spine deformity surgery with and without osteotomies. MATERIALS AND METHODS: The perioperative data from 548 patients who underwent ≥ 3 levels of posterior spinal fusion with instrumentation between January 1, 2003 and May 30, 2009, were retrospectively collected to create a model for predicting major blood transfusion. The validity of the model was retrospectively tested with a separate data set of 95 patients who underwent surgery from June 1, 2009 through September 30, 2010. RESULTS: There was a 59.5% incidence of major transfusion in the derivation set of patients. Independent predictors of major transfusion were operation duration, number of posterior levels instrumented, surgical complexity score, and preincision hemoglobin. This model was able to predict major transfusion significantly better than a previously published model (ROCAUC=0.89; 99% confidence interval, 0.80-0.90; P<0.001). CONCLUSIONS: Our model has an increased accuracy for predicting the probability of major transfusion compared with a previously published model. In addition, our model is applicable to all types of spine fusion surgery and accounts for the complexity of surgical instrumentation, the number of levels instrumented, and the predicted duration of surgery as independent variables.

The incidence of unacceptable movement with motor evoked potentials during craniotomy for aneurysm clipping.

OBJECTIVE: To review the experience at a single institution with motor evoked potential (MEP) monitoring during intracranial aneurysm surgery to determine the incidence of unacceptable movement. METHODS: Neurophysiology event logs and anesthetic records from 220 craniotomies for aneurysm clipping were reviewed for unacceptable patient movement or reason for cessation of MEPs. Muscle relaxants were not given after intubation. Transcranial MEPs were recorded from bilateral abductor hallucis and abductor pollicis muscles. MEP stimulus intensity was increased up to 500 V until evoked potential responses were detectable. RESULTS: Out of 220 patients, 7 (3.2%) exhibited unacceptable movement with MEP stimulation-2 had nociception-induced movement and 5 had excessive field movement. In all but one case, MEP monitoring could be resumed, yielding a 99.5% monitoring rate. CONCLUSIONS: With the anesthetic and monitoring regimen, the authors were able to record MEPs of the upper and lower extremities in all patients and found only 3.2% demonstrated unacceptable movement. With a suitable anesthetic technique, MEP monitoring in the upper and lower extremities appears to be feasible in most patients and should not be withheld because of concern for movement during neurovascular surgery.