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Same day discharge or outpatient surgery for intracranial procedures has become possible with the advent of image-guided minimally invasive approaches to surgery and availability of short-acting anesthetic agents. In addition, patient satisfaction and the benefits of avoiding hospital stay have resulted in the evolution of neurosurgical day surgery. We reviewed our experience and the available literature to determine the perioperative factors involved which have promoted and will improve this concept in the future. Craniotomy and biopsy for supratentorial brain tumors and surgical clipping of intact cerebral aneurysms have been successfully performed as day surgeries. Patient perceptions and satisfaction surveys have helped in better understanding and delivery of care and successful outcomes. There are major differences in health care across the globe along with socioeconomic, medicolegal, and ethical disparities, which must be considered before widespread application of this approach. Nevertheless, collaborative effort by surgeons, anesthesiologists, and nurses can help in same day discharge of patients after cranial neurosurgery.

In this review, we will discuss the anesthetic approach to outpatient neurosurgical procedures: craniotomy for tumor, anterior cervical decompression and fusion, and lumbar discectomy. The anesthesia team must be involved for the entire perioperative period: preoperative screening in preadmission clinic to optimize patient comorbidities and to assess suitability for same-day discharge; judicious sedation and anesthesia with short-acting agents and minimally invasive surgical techniques to expedite surgeries and minimize complications; and aggressive treatment of pain, nausea, and vomiting coupled with vigilance for complications and assessment of readiness for discharge. Successful day surgery programs focus on patient safety, optimized surgical and anesthetic techniques, and the selection and education of appropriate patients. The safety and feasibility of ambulatory neurosurgery depend on the development of stringent protocols and collaboration from nursing, surgery, and anesthesia teams.

BACKGROUND Stereotactic headframe-based imaging is often needed for target localization during surgery for insertion of deep brain stimulators. A major concern during this surgery is the need for emergency airway management while an awake or sedated patient is in the stereotactic headframe. The aim of our study was to determine the ease of emergency airway management with a stereotactic headframe in situ. MATERIALS AND METHODS We conducted an observational study using a mannequin. A Leksell stereotactic headframe was placed on a mannequin in the operating room and the frame was fixed to the operating room table. Anesthesia personnel were asked to insert a #4 laryngeal mask and then to intubate the mannequin, using both direct (DL) and video laryngoscopy (VL). In addition, participants were asked to perform the same airway techniques in the mannequin without the headframe. Data were analyzed for time taken for airway management using different devices with and without the headframe. In addition, we compared the time taken to secure the airway between different participant groups. RESULTS Thirty anesthesia personnel (7 residents, 12 fellows, and 11 consultants) participated in the study. With the headframe in situ, 97% of participants were able to insert a laryngeal mask on their first attempt; 93% and 97% of participants were able to intubate the mannequin using DL and VL respectively on their first attempt. Without the stereotactic headframe, all participants were able to insert the laryngeal mask and intubate on the first attempt. The average time taken to insert a laryngeal mask and intubate the mannequin using DL and VL with the headframe in situ was 39.3, 58.6, and 54.8 seconds, respectively. CONCLUSIONS Our study showed that both laryngeal mask insertion and tracheal intubation can be performed with a stereotactic headframe in situ. A laryngeal mask is the quickest airway device to insert and can be inserted while the mannequin is in the standard surgical position. Further study is needed to validate the results in patients.

Macroglossia, an abnormal swelling of the tongue, is a rare post-operative complication often associated with serious airway obstruction and prolonged intubations. Currently, there is a paucity of information on the true incidence, aetiology, and complications associated with macroglossia. A thorough review of the literature was carried out so as to summarise the characteristics of reported cases of macroglossia and to present potential treatments and preventive strategies. A literature search was conducted in PubMed to identify human case reports of macroglossia after neurosurgical procedures including spine, published in English from 1974 to December 2015. A total of 26 reports with 36 cases of macroglossia were identified. Macroglossia was most commonly reported after sub-occipital and/or posterior fossa craniotomies and spine surgeries in prone or park-bench positions. It is more common after procedures lasting >8 h. The aetiology of macroglossia is multi-factorial and possible mechanisms included local mechanical tongue compression interfering with venous and/or lymphatic drainage, regional venous thrombosis and/or local trauma. Complications included airway obstruction, re-intubation, difficult re-intubation, prolonged intubation and Intensive Care Unit stay and tongue necrosis. Prevention, awareness of the possibility, and early recognition are the best forms of treatment.

Management of the airway may be challenging in patients undergoing occipito-cervical spine fusions (OCF). Changes in the occipito-cervical angle (dOC2A) of fusion after surgery may result in acute airway obstruction, dyspnea and/or dysphagia. Objectives of the study were to review the airway management of patients during posterior OCF, determine the incidence, nature and risk factors for postoperative airway adverse events (AEs), and to determine the relationship between airway AEs and the change in dOC2A. In this retrospective cohort of 59 patients, following extubation in the operating room (OR), there were no complications in 43 (73%) patients (Group 1). Sixteen (27%) patients (Group 2) had airway complications; 4 requiring reintubation and 12 having delayed extubation. The number of vertebral levels fused (>6), presence of difficult intubation and duration of surgery (>5 h) were significantly associated with AEs. There was no significant difference in the dOC2A between the groups (−1.070 ± 5.527 versus −4.375 ± 10.788, p = 0.127). Airway management in patients undergoing OCF poses a challenge for the anesthesiology and surgical teams. The incidence of AEs was 27%. The decision to extubate immediately after surgery needs to be individualized. Factors such as difficult intubation, number of vertebral levels fused and duration of surgery have to be considered. A significant correlation between dOC2A and postoperative AEs could not be established. Risk factors for postoperative AEs are multifactorial and prospective evaluation of these factors is indicated.

Enhanced Recovery After Surgery is a multimodal perioperative care pathway designed to achieve early discharge in patients undergoing major surgery. Recent advances in neurosurgery allow for shorter duration of anesthesia and surgery, faster recovery, and earlier discharge from hospital. The purpose of this retrospective observational study was to assess the incidence of early discharge from hospital in patients undergoing craniotomy for supratentorial brain tumours as well as to explore the associated perioperative factors, anesthesia techniques, and complications. The medical records of all patients who underwent craniotomy (less than four-hour duration) for supratentorial tumour over a five-year period were retrospectively reviewed. The data analyzed included the postoperative discharge destination, type of anesthesia—i.e., general anesthesia (GA) vs awake craniotomy (AC), and the incidence of adverse events. Data from 329 patients [mean (SD) age 48 (12) yr; 164 male, 165 female] were analyzed, including 198 (AC, n = 157; GA, n = 41) patients who were preoperatively scheduled for same-day discharge. Successful same-day discharge occurred in 175/198 (88.4%) of these patients (AC, n = 139; GA, n = 36). Five (2.9%) of the 175 patients (4 AC, 1 GA) with same-day discharge required readmission to hospital within the first 12 hr after discharge. Six (1.8%) of the 329 total patients had a documented postoperative intracranial bleed, but none occurred after initial discharge from hospital. Same-day discharge from hospital is possible in carefully selected patients after both GA and AC for supratentorial tumour surgery.

Introduction: Depth of anaesthesia (DOA) monitors are shown to reduce the intra-operative dose of anaesthetic agents, provide haemodynamic stability and shorten emergence times. Electroencephalography (EEG) based DOA monitors such as bispectral index (BIS) and entropy have been calibrated and validated in healthy subjects. Hence the clinical effectiveness of these monitors may be affected when monitoring patients with neurological disorders (e.g., epilepsy, dystonia, dementia and Parkinson’s disease). The aim of this study was to determine whether BIS and entropy correlate with each other and with clinical indices of DOA in patients with movement disorders under general anaesthesia (GA). Materials and Methods: We conducted a prospective, observational study in patients with movement disorders undergoing internalization of deep brain stimulators. All patients received standard GA with age-adjusted mean alveolar concentration (aaMAC) of an inhalational agent between 0.7 and 1.1. BIS and entropy sensors were applied on the patient’s left forehead. Data collected included clinical parameters and EEG-based DOA indices. Correlation analysis was performed between entropy, BIS and the clinical indices of DOA. Bland Altman analysis was performed to determine the agreement between BIS and entropy. Results: Thirty patients were studied (mean age was 58.4 ± 11 years, male: female 18:12 and weight 79.2 ± 17 kg). Indications for deep brain stimulation were Parkinson’s disease (n = 25), essential tremors (n = 2) and dystonia (n = 3). There was a very strong positive correlation between BIS and response entropy (RE) (r = 0.932) and BIS and state entropy (SE) (r = 0.950) and a strong negative correlation among aaMAC and BIS, RE and SE with r values of −0.686, −0.788 and −0.732, respectively. However, there was no correlation between BIS, RE, SE and haemodynamic values. Conclusion: Our study showed that BIS and entropy perform well in patients with movement disorders. There was a good correlation between the BIS and entropy devices. Haemodynamic parameters were not reliable indicators of DOA in these patients.

With increasing fiscal restraints on health care systems, procedural cost-effectiveness has become an important metric for evaluating surgical procedures. While outpatient craniotomy has been shown to be safe and effective, the economic implications of this procedure has yet to be examined. Here, we present the first cost analysis comparing inpatient versus outpatient awake craniotomy for tumor resection/biopsy.We conducted a retrospective chart review on consecutive patients undergoing awake craniotomy for tumor resection/biopsy at a publicly funded tertiary care center from Sept 2014 to Aug 2015. Patient demographics, comorbidities and surgical factors were recorded. Direct and indirect costs for each patient visit were calculated based on institutional records.A total of 50 consecutive patients undergoing awake craniotomy for tumor resection were included in this study (29 outpatients, 21 inpatients). Rates of complications and 30-day readmission were similar between groups. The total costs associated with inpatient surgery were nearly double that of outpatient surgery ($10649 versus $5242, P 0.001). In-patient surgery resulted in a nearly 6-fold increase in unit/bed costs compared to out-patient surgery ($4142 versus $758, P 0.001). There were no differences in the costs incurred from the operating room, laboratory, or anesthesia departments.Costs associated with outpatient craniotomy are nearly half compared to inpatient craniotomy and this is largely driven by reductions in bed resource utilization and allied health services. Outpatient neurosurgery for tumor resection is therefore a safe and feasible option for appropriately selected patients and confers an overall cost reduction.

Anesthetic modality and hemodynamic management during mechanical thrombectomy (MT) for acute ischemic stroke (AIS) are potential contributors to the success of revascularization. The aims of our study were to review the hemodynamic management by anesthesiologists and clinical outcomes in patients undergoing MT under conscious sedation.Retrospective cohort study of patients with anterior circulation AIS from January 2012 to March 2016. Primary outcome was hemodynamic intervention, defined as administration of vasoactive drugs to maintain systolic blood pressure (BP) between 140 and 180 mm Hg. The secondary outcome was poor hemodynamic control, defined as BP outside target for15 minutes despite hemodynamic intervention. We performed regression analysis to determine the predictors of hemodynamic intervention and poor hemodynamic control.A total of 126 patients were included in this study; 92% (116) receiving conscious sedation and 8% (10) no sedation. Upon arrival to the neuroradiology suite, systolic BP was140 mm Hg in 30.2% of the patients and180 mm Hg in 14.3%. Hemodynamic intervention was required in 38.9% of patients; 15.1% for hypotension and 19.8% for hypertension. In the multivariate analysis, systolic BP on hospital admission (odds ratio, 1.02; 95% confidence interval, 1.00-1.04; P=0.019) constituted a predictor for hemodynamic intervention. Poor hemodynamic control occurred in 12.7% of patients, with lower baseline systolic BP being associated with higher risk of intraprocedural hypotension (odds ratio, 0.92; 95% confidence interval, 0.89-0.96; P0.001). In-hospital mortality was 13.6%.Hemodynamic intervention is frequent during MT under conscious sedation. The routine presence of anesthesiologists during MT may be helpful in maintaining hemodynamic stability and allow rapid treatment of emergent complications. An individualized approach with tailored hemodynamic targets is required during management of patients undergoing MT for AIS.

Spine surgeries are increasingly being performed as a day or short-stay surgery programs. Peripheral nerve block provide site-specific pain relief with few side effects, thereby reducing surgical stress and enhancing quality of recovery. The aim of our study was to determine the effect of a superficial cervical plexus block (SCPB) on postoperative quality of recovery and analgesia in patients undergoing elective anterior cervical discectomy and fusion (ACDF).After Research Ethics Board approval, we enrolled adults ( 18 yr) scheduled for elective single- or two-level ACDF in this randomized double-blind clinical trial. Participants were randomized to receive either a SCPB (0.25% bupivacaine, 10 mL) or No Block. The primary outcome measure was the quality of recovery at 24 hr, measured using the 40-item quality of recovery questionnaire (QoR-40). In addition, comparisons between groups were also made for postoperative opioid consumption and discharge times.Forty-six patients were randomized to receive either a SCPB block (n = 23) or No Block (n = 23). Median [interquartile range] aggregated global QoR-40 scores at 24 hr were significantly greater in the SCPB group, indicating good quality of recovery compared with the No Block group (179 [116-195] vs 157 [97-196], respectively; median difference, 22; 95% confidence interval [CI], 7 to 34; P = 0.002]. There were no differences between the SCPB and the No Block group with regard to mean (standard deviation) postoperative opioid consumption at 24 hr [22.9 (13.6) mg vs 24.6 (9.5) mg, respectively; mean difference 1.7; 95% CI, -5.2 to 8.7; P = 0.620] and the number of patients discharged within 24 hr (15 vs 12, respectively; P = 0.550).We showed that preoperative SCPB is an effective strategy for improving the early quality of recovery in patients undergoing single- or two-level ACDF. Nevertheless, there was no impact on opioid consumption or discharge times. This trial was registered at www.clinicaltrials.gov (NCT01662219).

Introduction Controlling the arterial carbon dioxide tension (PaCO2) to reduce the cerebral blood flow (CBF) and the intracranial pressure is a common practice in neuroanesthesia. A change in CBF in response to change in PaCO2 is termed as cerebrovascular reactivity to carbon dioxide (CVR-CO2). Studies have shown that, both inhalational and intravenous anesthetic agents have variable effects on CVR-CO2 and the effect of anesthetic agents on CVR also varies with many physiological and pathologic conditions. The objectives of this review were to evaluate the effect of anesthetic agents on the CVR-CO2 in adults and to determine how this response is modified by other physiological and pathologic factors. Methods We conducted a systematic search of the databases of Medline, Embase, Cochrane Central Register of Controlled Trials, and Cochrane Database of Systematic Reviews using related term components for both CVR-CO2 and anesthesia. Our primary outcome of this review was to determine whether the CVR-CO2 is maintained under anesthesia. The other endpoints of this review are to determine the effect of other factors (age, sex, medical comorbidities, and cerebrovascular pathology) on the CVR-CO2 under anesthesia. Because of the methodological heterogeneity in the primary studies, quantitative analysis of the data was not possible, and therefore, we have summarized the data qualitatively. Results Our search strategy yielded 1356 citations. After excluding nonpertinent papers, 38 studies were included for the systematic review. Nineteen randomized controlled trials and 19 observational studies met inclusion criteria and a total of 793 patients were studied. Transcranial Doppler was the most commonly used method for measuring CBF and changing the respiratory rate and/or minute ventilation were the most commonly used method to change the CO2 tension. CVR-CO2 is maintained with both inhalational and intravenous anesthetic agents within the range of concentrations used in clinical anesthesia. At doses leading to a broadly equivalent depth of anesthesia, the reactivity value was highest with isoflurane and the least with propofol. Individual agents differ in their degree of reactivity to hypercapnic and hypocapnic stimuli. CVR-CO2 is impaired in elderly patients when compared with young patients with both sevoflurane and propofol anesthesia. In patients with medical comorbidities, the CVR-CO2 impairment under anesthesia was associated with the severity of the underlying diseases and not the anesthetic agents. Conclusions Our systematic review showed that within the clinical anesthesia concentrations, CVR-CO2 is maintained under both propofol and inhalational agents. However, most of the information available is from non-neurosurgical patients and these studies also suffer from significant methodological heterogeneity. Therefore, we were limited by the amount and the quality of data available for this review.

Background: Monitoring the depth of anaesthesia can be a challenge in patients undergoing supratentorial craniotomy because the conventional sensors for both bispectral index and entropy monitors lose their contact with a brain after scalp elevation. The new sensors for the entropy monitor are more flexible and can be placed in different locations. The purpose of this study was to determine the feasibility on the use of new GE entropy sensors in monitoring depth of anaesthesia in patients undergoing supratentorial craniotomy. Materials and Methods: We retrospectively reviewed the data from 20 consecutive patients undergoing supratentorial craniotomy who had the monitoring of the depth of anaesthesia using modified entropy sensors. Prior to the induction of anaesthesia, the new GE entropy sensor (P/N M1038681) was applied in a modified fashion. We measured the state entropy (SE) and response entropy (RE) at 12 perioperative time points. Entropy values were compared with the clinical indices of depth of anaesthesia. Results: Data from 20 consecutive patients (orbitozygomatic craniotomy [10] and bifrontal craniotomy [10]) were analysed. Monitoring was possible in all the patients. The changes in entropy values correlated with clinical indices of depth of anaesthesia. However, some patients showed variations in absolute values (RE and SE) during the intraoperative period without any changes in the level of anaesthetic depth. Conclusions: Monitoring the depth of anaesthesia is feasible with the use of new entropy sensors in patients undergoing supratentorial craniotomy. In contrast to standard sensors, the new sensors offer flexibility with the placement.

Cerebral revascularization is used to augment or replace cerebral blood flow in patients at risk of developing cerebral ischemia. These include patients with moyamoya disease, occlusive cerebrovascular disease, skull base tumors, and complex aneurysms. Our aim in this review is to provide a comprehensive update of both surgical and anesthetic aspects of cerebral revascularization procedures. The anesthetic concerns for most patients presenting for different types of bypass procedures are similar and include the maintenance of adequate cerebral perfusion to prevent cerebral ischemia. Patients with complex aneurysms and tumors have additional considerations related to the surgical treatment of the underlying pathology.

Background: Cerebral vasospasm is a common and devastating complication after a subarachnoid haemorrhage (SAH). Current guidelines for treatment recommend hypertension with euvolaemia. Endovascular therapy with cerebral angioplasty and possible administration of intra-arterial vasodilators is indicated in patients who fail medical treatment. The objective of our study was to review the haemodynamic management and anaesthetic care of patients undergoing endovascular therapy for cerebral vasospasm in our institution. Materials and Methods: The medical records of all patients who underwent endovascular therapy for cerebral vasospasm between, April 2006 and September 2012, were reviewed retrospectively. Patients with clinical vasospasm were treated initially by inducing hypertension to systolic pressures of 140 to 170 mmHg; Endovascular treatment was performed, if there was no clinical improvement. Data was collected on blood pressure measurements, anaesthetic management, duration and complications of hypertensive therapy and outcome. The differences in the pre- and post-angioplasty systolic blood pressure were statistically analysed. Results: A total of 45 patients had 47 endovascular interventions, with balloon angioplasty for proximal vessel spasm and 16 (34%) patients had additional intra-arterial injection of a vasodilator agent. Onset of vasospasm was 7 days (range 2-15 days) after SAH. Vasospasm was usually seen in multiple vessels in the same patient regardless of the site of ruptured aneurysm and was present unilaterally in 80% of the patients. All patients had a general anaesthesia for the procedure. Prior to endovascular treatment 68.9% patients required vasopressors, but post angioplasty 93.3% required them. Norepinephrine was the most commonly used (66.2%). Angioplasty was successful in reversing the cerebral vasospasm as assessed by angiography in all patients with no intra-procedure complications. Overall 80% of patients were discharged from hospital to home or to a rehabilitation centre. Conclusion: Cerebral vasospasm affects multiple vessels in the same patient. Despite endovascular therapy being a successful intervention for proximal vessel spasm, most patients still required induced hypertension with even higher levels post angioplasty compared to pre angioplasty.

Background: Subthalamic nucleus deep brain stimulation (STN–DBS) has become a standard treatment for many patients with Parkinson’s disease (PD). The reported clinical outcome measures for procedures done under general anesthesia (GA) compared to traditional local anesthetic (LA) technique are quite heterogeneous and difficult to compare. The aim of this systematic review and metaanalysis was to determine whether the clinical outcome after STN–DBS insertion under GA is comparable to that under LA in patients with Parkinson’s disease. Methods: The databases of Medline Embase, Cochrane library and Pubmed were searched for eligible studies (human trials, English language, published between 1946 and January of 2016). The primary outcome of this study was to assess the postoperative improvement in the symptoms, evaluated using either Unified Parkinson’s Disease Rating Scale (UPDRS) scores or levodopa equivalent dosage (LEDD) requirement. Results: The literature searches yielded 395 citations and six retrospective cohort studies with a sample size of 455 (194 in GA and 261 in LA) were included in the analysis. Regarding the clinical outcomes, there were no significant differences in the postoperative Unified Parkinson’s disease rating scale and levodopa equivalent drug dosage between the GA and the LA groups. Similarly, the adverse events and target accuracy were also comparable between the groups. Conclusions: This systematic review and meta-analysis shows that currently there is no good quality data to suggest equivalence of GA to LA during STN-DBS insertion in patients with PD, with some factors trending towards LA. There is a need for a prospective randomized control trial to validate our results.

During spinal surgery, intraoperative monitoring of motor-evoked potentials (MEPs) is a useful means of assessing the intraoperative integrity of corticospinal pathways. However, MEPs are known to be particularly sensitive to the suppressive effects of inhalational halogenated anesthetic agents.To investigate the effects of increasing end-tidal concentrations of desflurane and sevoflurane anesthesia in a background of propofol and remifentanil with multipulse cortical stimulation on intraoperative monitoring of MEPs.In this randomized crossover trial, 14 consecutive patients (7 in each arm) undergoing major spine surgery, under a background anesthetic of propofol (75 to 125 mcg/kg/min) and remifentanil (0.1 to 0.2 mcg/kg/min), were randomly assigned to receive the sequence of inhalational agents studied: either DES-SEVO (desflurane followed by sevoflurane); or SEVO-DES (sevoflurane followed by desflurane). Multiples (0.3, 0.5, and 0.7) of minimum alveolar concentration (MAC) of desflurane and sevoflurane were administered. After a washout period of 15 minutes using high fresh oxygen/air flows, each of the patients then received the other gas as the second agent. Cortical stimulation was achieved with a train of 5 equivalent square pulses, each 0.05 ms in duration, delivered at 2 ms intervals. MEP recordings were made in the upper limb (UL) from first dorsal interosseus and lower limb (LL) from tibialis anterior with subdermal needle electrodes.At 0.3 MAC desflurane, there was no statistical significant difference in transcranial-evoked MEP amplitudes from the baseline in both UL and LL stimulation. However, this was not the case for sevoflurane for which even a low concentration at 0.3 MAC significantly depressed MEP amplitudes of LL (but not UL) from baseline value. Desflurane at 0.5 and 0.7 MAC depresses LL MEP to 58.4% and 59.9% of baseline, respectively (P0.05), whereas sevoflurane at 0.3, 0.5, and 0.7 MAC depresses LL MEP to 66.2%, 41.3%, and 25.3% of baseline, respectively (P0.05). There was no difference in latency of the responses at any MAC.Inhalational anesthetic agents (sevofluranedesflurane) suppress MEP amplitudes in a dose-dependent manner. The use of 0.3 MAC of desflurane (but not sevoflurane) provided good MEP recordings acceptable for clinical interpretation for both upper and LLs. The LL appears to be more sensitive to anesthetic-induced depression compared with the UL. All patients studied had normal neurological examination hence, these results may not be applicable to those with preexisting deficits.

Both propofol and volatile anesthetics are commonly used for maintenance of anesthesia in patients undergoing neurosurgical procedures. The effects of these two classes of drugs on cerebral hemodynamics have been compared in many clinical trials The objectives of this review were to evaluate the cerebral hemodynamic effects, operative conditions, recovery profiles, postoperative complications, and neurological outcomes of propofol-based vs volatile-based anesthesia for craniotomy. MEDLINE®, EMBASE™, Cochrane, and other relevant databases were searched for randomized controlled trials that compared propofol-maintained anesthesia with volatile-maintained anesthesia in adult patients undergoing elective craniotomy. The primary outcome measure was the intraoperative brain relaxation score. Secondary outcome measures included intraoperative cerebral hemodynamics (intracranial pressure [ICP], cerebral perfusion pressure [CPP]), cardiovascular changes, recovery profiles, postoperative complications, and clinical outcomes (neurological morbidity, mortality, quality of life). A meta-analysis was conducted using a random effects model to compare the outcomes of the two anesthetic techniques. Fourteen studies (1,819 patients) met inclusion criteria and were analyzed. Brain relaxation scores were similar between the two groups after dural opening; however, ICP was lower (weighted mean difference of −5.2 mmHg; 95% confidence interval −6.81 to −3.6) and CPP was higher (weighted mean difference of 16.3 mmHg; 95% confidence interval 12.2 to 20.46) in patients receiving propofol-maintained anesthesia. Postoperative complications and recovery profiles were similar between the two groups, except for postoperative nausea and vomiting being less frequent with propofol-maintained anesthesia. There were inadequate data to perform a meta-analysis on clinical outcome. Propofol-maintained and volatile-maintained anesthesia were associated with similar brain relaxation scores, although mean ICP values were lower and CPP values higher with propofol-maintained anesthesia. There are inadequate data to compare clinically significant outcomes such as neurological morbidity or mortality.

Background: Ambulatory day surgery is an evolving specialty in line with demands of modern medicine, health care services, and economics, but its role in neurovascular surgery remains controversial. The purpose of this study was to describe our experience of patients undergoing elective clipping of intact cerebral aneurysms as day surgery. Methods: This retrospective and prospective observational study was carried out as a cohort review of patients who underwent outpatient clipping of an intact intracranial aneurysm at the Toronto Western Hospital, University Health Network, between May 2009 and November 2012. Patients were categorized as success (discharged on the same day) or failure (requiring unplanned postoperative hospital admission) of day surgery. Data included the preoperative assessment of the patient, anesthetic management, postoperative care, and the incidence of perioperative complications. Outcomes were duration of hospital stay, and any problems preventing same-day discharge. Results: During the study period 25 patients aged 54±9 years underwent outpatient aneurysm repair. Seventeen patients (68%) successfully completed day surgery, and 8 patients (32%) were admitted to the hospital after surgery due to perioperative complications. Duration of hospital stay in the failure group ranged from 2 to 18 days. Conclusions: Our data demonstrates that surgical clipping of unruptured cerebral aneurysms may be performed in an outpatient setting. Careful selection of day surgery candidates and postoperative assessment for complications is needed. Further research is needed to identify potential risk factors and to target patient subgroups for successful ambulatory surgery.

Deep brain stimulation (DBS) can be an effective treatment option for patients with essential tremor and Parkinson’s disease. This review provides an overview on the functioning of neurostimulators and recent advances in this technology and presents an updated guide on the anesthetic management of patients with an implanted neurostimulator undergoing surgery or medical intervention. A search was conducted on MEDLINE®, EMBASE™, and Cochrane Database of Systematic Reviews databases to identify studies published in English from 1974 to December 2015. Our search also included relevant and available incident reports from the manufacturers, Health Canada, the United States Food and Drug Administration, and the European Medicines Agency. Thirty of 232 articles identified were found to be relevant to this review. Deep brain stimulation systems now offer a range of options, including pulse generators with dual-channel capabilities, rechargeable batteries, and current-control modes. Preoperatively, the anesthesiologist should ascertain the indications for DBS therapy, identify the type of device implanted, and consult a DBS specialist for specific precautions and device management. The major perioperative concern is the potential for interactions with the medical device resulting in patient morbidity. Neurostimulators should be turned off intraoperatively to minimize electromagnetic interference, and precautions should be taken when using electrosurgical equipment. Following surgery, the device should be turned on and checked by a DBS specialist. The anesthesiologist plays an important role to ensure a safe operating environment for patients with an implanted DBS device. Pertinent issues include identifying the type of device, involving a DBS-trained physician, turning off the device intraoperatively, implementing precautions when using electrosurgical equipment, and checking the device postoperatively.

Perioperative hypoxia is a serious complication resulting in morbidity and mortality. There are various causes of hypoxia, but frequently it is associated with airway management during general anesthesia. Monitoring of oxygen saturation is routinely performed.

Deep brain stimulation is used for the treatment of patients with neurologic disorders who have an alteration of function, such as movement disorders and other chronic illnesses. The insertion of the deep brain stimulator (DBS) is a minimally invasive procedure that includes the placement of electrodes into deep brain structures for microelectrode recordings and intraoperative clinical testing and connection of the DBS to an implanted pacemaker. The anesthetic technique varies depending on the traditions and requirements of each institution performing these procedures and has included monitored anesthesia with local anesthesia, conscious sedation, and general anesthesia. The challenges and demands for the anesthesiologist in the care of these patients relate to the specific concerns of the patients with functional neurologic disorders, the effects of anesthetic drugs on microelectrode recordings, and the requirements of the surgical procedure, which often include an awake and cooperative patient. The purpose of this review is to familiarize anesthesiologists with deep brain stimulation by discussing the mechanism, the effects of anesthetic drugs, and the surgical procedure of DBS insertion, and the perioperative assessment, preparation, intraoperative anesthetic management, and complications in patients with functional neurologic disorders.

In ancient times, awake craniotomy was used for trepanation to treat seizures and remove a variety of morbid conditions or even to permit the escape of evil air. In modern times, this technique was initially used for removal of epileptic foci with simultaneous application of brain mapping with electrical current. Further developments brought this technique into use for resection of tumors involving functional cortex. Recently, awake craniotomy has been described as an approach for removal of supratentorial tumors nonselectively, regardless of the involvement of eloquent cortex. It has been used in North America since the 1980s, then Europe, and recently has spread into Asia. Its spread to Asia could have significant impact based on the large population of patients and the low resource utilization associated with awake craniotomy.

Anxiety is common in surgical patients, with an incidence of 60% to 92%. There is little information on the incidence and severity of preoperative anxiety in patients scheduled for neurosurgery. The aim of this study was to measure the level of preoperative anxiety in neurosurgical patients and to assess any influencing factors. After the Institutional Review Board approval and informed written consent, 100 patients booked for neurosurgery were interviewed preoperatively. Each patient was asked to grade their preoperative anxiety level on a verbal analog scale, Amsterdam Preoperative Anxiety and Information Scale, and a set of specific anxiety-related questions. The anxiety scores and the responses to the questions were compared between the sex, age, weight, diagnosis, and history of previous surgery. The mean age (+/-SD) was 50+/-13 years. The preoperative diagnosis was tumor (n=64), aneurysm (n=14), and other (n=22). Overall verbal analog scale was 5.2+/-2.7; the score was higher for female (5.8+/-2.8) than male patients (4.6+/-2.5) (P

BACKGROUND: Agriculture is one of the most hazardous occupations in the world. The aim of an occupational health service (OHS) is to reduce the risk of work-related diseases, occupational diseases and injuries and to promote workers' health. In Finland, they are part of the public health care system, but for farmers OHS is voluntary. AIMS: To explore factors associated with farmers joining farmers' occupational health services (FOHS). This knowledge is important for improving the coverage of FOHS and to motivate farmers to join. METHODS: In 2004 and 2005, we interviewed a total of 1182 full-time farmers aged 18-64, chosen randomly from the register of the Information Centre of the Ministry of Agricultural and Forestry in Finland (Tike). A stepwise multivariate logistic regression model was used to calculate odds ratios and their 95% confidence intervals for factors associated with their joining FOHS. RESULTS: Among both genders, chronic illnesses, farm size and opinion on whether membership of FOHS should be obligatory were predictors of farmers joining FOHS. Among male farmers, the production sector, the existence of a quality system on the farm and vocational education were associated with interest in joining. Among female farmers, interest was associated with physical activity. CONCLUSIONS: Emphasizing FOHS constitutes a preventive approach. All farmers should be motivated by FOHS to become aware of issues concerning safety and health at work. The potential channels for increasing its awareness are vocational education, quality systems and support from farmers who are already members. Language: en

The results of previous studies on the association between bone mineral density (BMD) and chronic spinal syndromes have been contradictory. Therefore, we studied relative BMD measured by the metacarpal index (MCI) and its associations with chronic neck and low-back syndromes and diffuse idiopathic skeletal hyperostosis (DISH).A population sample of 8000 Finns aged 30 years and over was invited to a comprehensive health examination in 1978-1980; 90% complied. In the clinical phase, a trained physician diagnosed chronic neck and low-back syndromes. Hand and chest radiographs were taken from 3568 participants to determine the MCI and to diagnose DISH. Of these, 340 subjects were re-examined clinically in 2000.After adjusting for potential confounding factors, a high MCI showed a significant cross-sectional association with chronic neck syndrome and DISH. The odds ratio (OR) per increment of one standard deviation (0.1) of MCI for chronic neck syndrome was 1.33 [95% confidence interval (CI) 1.21-1.47] and for DISH 1.29 (95% CI 1.04-1.60). No association was found between MCI and chronic low-back syndrome. In the follow-up setting, however, baseline MCI did not predict the incidence of chronic neck or low-back syndromes.Relative BMD is directly proportional to the prevalence of chronic neck syndrome. Further studies are needed to clarify the mechanisms of the association. The close association found between high relative BMD and DISH suggests a joint metabolic factor, which needs to be studied further to determine its effects on bones and intervertebral discs.

The use of functional stereotactic neurosurgery is increasing for treatment of patients with movement disorders and other chronic illnesses. The anesthetic considerations include the influence of the anesthetic agents on the microelectrode recordings and stimulation testing of an awake patient. The purpose of this study was to review the anesthetic management and incidences of intraoperative complications during functional neurosurgery in our institution. One hundred seventy-eight patients underwent an ablative procedure (n = 6) or the insertion of deep brain stimulator (n = 172) under monitored anesthesia care for movement disorders (n = 124), chronic pain (n = 20), and other procedures (n = 34). Local anesthetic was used for head frame pin sites and burr holes. No sedation/analgesia was administered to 57 (32%) patients. One patient required conscious sedation and another general anesthesia for the entire procedure. The remainder received small increments (mean +/- SD) of propofol (113 +/- 73 mg), midazolam (1.6 +/- 0.8 mg), and/or fentanyl (93 +/- 55 mug). Intraoperative complications that occurred in 16% of the patients included seizures (n = 8), change in neurologic status (n = 5), airway obstruction (n = 2), and hypertension (n = 7). Functional neurosurgery can be performed with minimal anesthesia in many patients. Awareness and vigilance can improve the identification and early treatment of intraoperative complications such as seizures, loss of airway, and changes in the neurologic status.

Background Metacarpal index (MCI), measured from hand radiographs as the ratio between combined cortical thickness and bone diameter, has been suggested for assessment of bone mass and risk of osteoporotic fracture. We studied MCI for its ability to predict hip fractures.Methods Hand radiographs were taken and MCI determined in 3,561 subjects from a representative population sample of 8,000 Finns who were 30 years of age or over in 1978–80. Record linkage to the National Hospital Discharge Register identified 117 subjects who had been hospitalized for primary treatment of hip fracture by the end of 1994.Results High age, low body mass index, tall stature and smoking at baseline showed, independently of each other, significant associations with low MCI. Low MCI was a strong predictor of hip fracture. When adjusted for all potential confounding factors, the relative risk of hip fracture per decrement of MCI by one standard deviation (0.1) was 1.5 (95% CI 1.2–1.8).Interpretation Low MCI is associated with kn...

Objectives. A number of previous studies have reported an inverse relationship between osteoarthritis and osteoporosis. However, the association has remained controversial because osteoarthritis in hand joints seems to associate differently from osteoarthritis in weight-bearing joints with bone mineral mass. We studied osteoarthritis in distal interphalangeal (DIP) joints and osteoarthritis in the base of the thumb (CMC-1) for their cross-sectional associations with metacarpal cortical bone mineral mass, and for their prediction of calcaneal broadband ultrasound attenuation. Methods. A population sample of 8000 Finns aged 30 yr and over was invited to a comprehensive health examination in 1978–1980; 90% complied. Hand radiographs were taken from 3568 participants to diagnose osteoarthritis in various hand joints, and to determine two indicators of cortical bone mineral mass, the combined cortical thickness (CCT) and the metacarpal index (MCI). Calcaneal broadband ultrasound attenuation was measured 20 yr later in 340 of these participants with the Sahara sonometer. Results. In the cross-sectional setting, osteoarthritis in the DIP joints and osteoarthritis in the base of the thumb (CMC-1) were significantly associated with low CCT and low MCI. These associations were proportional to the radiological severity of osteoarthritis. In the follow-up setting, symmetrical DIP osteoarthritis adjusted for age, sex, body mass index, smoking, education, workload and MCI significantly predicted low values of broadband ultrasound attenuation. Conclusions. Our results indicate a direct relation of both radiological DIP osteoarthritis and CMC-1 osteoarthritis with low cortical bone mineral mass, in proportion to the severity of osteoarthritis. The presence of symmetrical DIP osteoarthritis, a possible indicator of generalized osteoarthritis, suggests an increased risk of osteoporosis over time.

The role of anesthesia outside the operating room is rapidly expanding and evolving alongside with the advances in interventional neuroradiology. Increasingly complex diagnostic and therapeutic neuroradiological procedures are being performed on sicker patients. This review provides an overview of the principles of anesthetic management and summarizes recent advances in interventional neuroradiology.There are many new areas of development in interventional neuroradiology, but each also brings with it controversy. Use of newer agents for anesthesia and for anticoagulation may change the intraoperative management of patients. The role of neurophysiological monitoring during endovascular procedures is still to be validated. The optimal mode of treating cerebral aneurysms is still being debated. There has been increasing interest in and evidence of the efficacy of carotid artery stenting in the treatment of carotid artery disease. The utility of intraoperative magnetic resonance imaging in neurosurgery is expanding rapidly.Providing anesthesia in the interventional neuroradiology suite continues to be a challenge to the anesthesiologist. Understanding the anesthetic constraints and complexities and keeping abreast of the current developments in neuroradiology are crucial in ensuring the maximal benefits to and safety of patients.

Hyperglycemia should be avoided during neurosurgery in order to decrease the risk of neurological injury. Dexamethasone has been associated with increased blood glucose during surgery. In this prospective, nonrandomized study, we documented the blood glucose concentration changes for 12 h in 34 nondiabetic patients undergoing craniotomy and compared patients who received intraoperative dexamethasone (10 mg IV on induction and 4 mg IV 6 h later), with or without preoperative dexamethasone, with patients who did not receive dexamethasone. Blood glucose concentrations increased from the preinduction value in all groups. Patients not taking dexamethasone before surgery, but who were given it intra- and postoperatively, had the largest peak blood glucose concentrations (11.0 +/- 2.0 mmol/L, mean +/- sd; P < 0.01) compared with patients who received no dexamethasone (7.8 +/- 2.1 mmol/L) or those who had been taking dexamethasone before surgery and continued it during surgery (8.5 +/- 1.2 mmol/L). The peak blood glucose concentrations in this group occurred 9 +/- 2 h after the induction of anesthesia. We recommend that the blood glucose concentration be monitored for at least 12 h in nondiabetic patients having neurosurgery who are newly administered dexamethasone.

Objective: To examine the effect of weight changes between 20 and 50 years of age on the risk of severe knee osteoarthritis (OA) requiring arthroplasty. Subjects and methods: Cases were 55–75 year old men and women (n = 220) having had knee arthroplasty for primary osteoarthritis at the Kuopio University Hospital in 1992–93. Controls (n = 415) were randomly selected from the population of Kuopio Province. Weight at the age of 20, 30, 40, and 50 years was collected retrospectively with a postal questionnaire. Results: After adjustment for age, sex, history of physical workload, recreational physical activity, and previous knee injury, weight gain resulting to a shift from normal body mass index (BMI ⩽25 kg/m 2 ) to overweight (BMI >25 kg/m 2 ) was associated with a higher relative risk of knee OA requiring arthroplasty than persistent overweight from 20−50 years of age, compared with those with normal relative weight during the corresponding age period. The odds ratios (OR) were 3.07 (95% confidence interval 1.87 to 5.05) for those with normal weight at the age of 20 years and overweight at two or three of the ages 30, 40 or 50 years, 3.15 (1.85 to 5.36) for those with overweight from the age of 30 years, and 2.37 (1.21 to 4.62) for those with overweight from the age of 20 years, respectively. Conclusion: In adult life, a shift from normal to overweight may carry a higher risk for knee OA requiring arthroplasty than does constant overweight.

To illustrate the anesthetic management of a craniotomy for suprasellar meningioma in a 28-week pregnant woman and to review the considerations for fetal monitoring during surgery.A 33-yr-old woman presented at 28 weeks of gestation with rapidly deteriorating vision in her right eye. Neuroradiological investigations revealed a large suprasellar meningioma extending into the frontal lobe. She underwent a craniotomy for excision of the tumour at 28 weeks gestation because of the risk of irreversible blindness. Anesthetic management was tailored for pregnancy and an intracranial tumour. Intraoperative blood pressure was maintained within 10% of baseline and respiratory variables were stable. No fetal heart rate monitoring was used during the surgery, as there was no plan to perform an emergency Cesarean delivery even in the event of change in fetal monitoring. The aim was to treat the mother aggressively for any untoward events. She made a good neurological recovery after the procedure and had a spontaneous vaginal delivery at 40 weeks of gestation without any neonatal complications.Anesthetic management of a brain tumour during pregnancy should be tailored to the individual patient according to the circumstances. It is possible to perform this type of procedure without fetal heart rate monitoring. The decision regarding fetal monitoring should be based on the consensus of the multidisciplinary care team and the mother.

Purpose To compare the recovery profiles, efficacy and safety of remifentanil and morphine for transitional analgesia with fentanyl in patients undergoing elective craniotomy for supratentorial mass lesions.

Background Opioids are known to stimulate surface electroencephalographic activity in patients with temporal lobe epilepsy. The objective of the current study was to compare the electrocorticographic activation effects of the newer short-acting opioid remifentanil with those of alfentanil during epilepsy surgery under general anaesthesia. Methods Thirteen patients undergoing temporal lobe epilepsy surgery under general anaesthesia received alfentanil 30 μg kg−1 and remifentanil 1 μg kg−1 as i.v. boluses in sequence. The design was a randomized double-blind cross-over study. After opening the dura, electrocorticogram (ECoG) electrode contact strips were placed over the temporal and supratemporal neocortex and depth electrodes were inserted in the amygdala and hippocampus. Alfentanil 30 μg kg−1 or remifentanil 1 μg kg−1 were administered randomly in a blinded fashion. The ECoG was recorded continuously before and after the injection of each drug. The interictal epileptiform activity (spikes and sharp waves) above baseline was analysed. Results Both drugs increased epileptiform activity especially that recorded from depth electrodes in the temporal limbic structures. No epileptiform activity was recorded from the electrodes overlying the supratemporal neocortex before or after drug administration. The more potent activator was alfentanil, which caused an increase in activation from baseline of 99.8% compared with 67.4% for remifentanil. In addition, alfentanil activated the epileptiform activity in 3 patients in which remifentanil had no effect. There were no changes in heart rate after the opioid boluses. Both remifentanil and alfentanil caused significant reductions in blood pressure at 3 and 5 min after administration. Conclusion We conclude that at the doses used in this study, alfentanil is the better opioid for intraoperative activation of the ECoG in neurosurgical patients undergoing resection of a temporal lobe epileptic focus. This pharmacological activation of epileptiform activity assists in localizing and confirming the site of surgical excision. Neither alfentanil nor remifentanil activated epileptiform activity in non-epileptic brain tissue.

Study Objective: To assess the frequency of postoperative nausea and vomiting (PONV) in patients following an awake craniotomy compared to general anesthesia for tumor surgery. Design: Prospective observational and chart review of all patients having a craniotomy for tumor during one year. Setting: Postanesthesia care unit (PACU) and intensive care unit (ICU) of a university hospital. Patients: 187 patients were reviewed. 107 patients who had a craniotomy for supratentorial tumor that was less than six hours in duration were analyzed and compared (50 awake craniotomy vs . 57 general anesthesia). Interventions: Medical records were reviewed for events after the first four hours until discharge. The occurrence and the time of any nausea, vomiting; the administration of antiemetics and analgesic drugs; and complications were documented. Measurements: Frequency of nausea, vomiting, administration of antiemetics and analgesia, and outcome between the two groups were compared using Chi-square and Student's t -test. Main Results : The frequency of nausea (4% vs. 23%; p=0.012) and vomiting (0% vs. 11%; p=0.052) were less in patients having an awake craniotomy compared to general anesthesia, but only during the first four hours. The administration of postoperative analgesia was not different between the two groups and did not influence the frequency of PONV. Conclusion: The frequency of PONV during the initial recovery phase was less in patients having an awake craniotomy for tumor surgery than in patients having a similar procedure with general anesthesia.

Background: The use of intraoperative neuromonitoring is a well-established method of detecting neurologic injuries during spine surgery. Anaesthesia, especially inhalational agents, influence motor evoked potential (MEP) monitoring. The aim of our study was to compare the effect of balanced anaesthesia (BA) (intravenous plus inhalational anaesthesia) and total intravenous anaesthesia (TIVA) on the incidence of intraoperative neuromonitoring changes, interventions performed and neurological outcomes of patients following high-risk spinal surgery. Methods: After Research and Ethics Board approval, a retrospective review of 155 patients who underwent spinal surgery with MEP was performed. Data were collected on changes in MEP and/or somatosensory evoked potential, interventions performed and neurological outcomes. Patients were divided into BA and TIVA groups and data were analysed. Results: A total of 152 patients were eligible for the study (mean age 54 ± 17, male: female 45:55). A BA technique was used in 62% and TIVA in 38%. Desflurane (