Cerebral autoregulation derived blood pressure targets in elective neurosurgery.

Poor postoperative outcomes may be associated with cerebral ischaemia or hyperaemia, caused by episodes of arterial blood pressure (ABP) being outside the range of cerebral autoregulation (CA). Monitoring CA using COx (correlation between slow changes in mean ABP and regional cerebral O2 saturation-rSO2) could allow to individualise the management of ABP to preserve CA. We aimed to explore a continuous automated assessment of ABPOPT (ABP where CA is best preserved) and ABP at the lower limit of autoregulation (LLA) in elective neurosurgery patients. Retrospective analysis of prospectively collected data of 85 patients [median age 60 (IQR 51-68)] undergoing elective neurosurgery. ABPBASELINE was the mean of 3 pre-operative non-invasive measurements. ABP and rSO2 waveforms were processed to estimate COx-derived ABPOPT and LLA trend-lines. We assessed: availability (number of patients where ABPOPT/LLA were available); time required to achieve first values; differences between ABPOPT/LLA and ABP. ABPOPT and LLA availability was 86 and 89%. Median (IQR) time to achieve the first value was 97 (80-155) and 93 (78-122) min for ABPOPT and LLA respectively. Median ABPOPT [75 (69-84)] was lower than ABPBASELINE [90 (84-95)] (p < 0.001, Mann-U test). Patients spent 72 (56-86) % of recorded time with ABP above or below ABPOPT ± 5 mmHg. ABPOPT and ABP time trends and variability were not related to each other within patients. 37.6% of patients had at least 1 hypotensive insult (ABP < LLA) during the monitoring time. It seems possible to assess individualised automated ABP targets during elective neurosurgery.

Preoperative triage to detect SARS-CoV-2 infection in surgical patients: lessons learned for resuming surgery.

PURPOSE: To define the impact of the COVID-19 outbreak on hospital surgical activity and assess the incidence of perioperative COVID-19 within two protocolized screening pathways for elective and non-elective surgery. METHODS: We conducted a prospective cohort study of adults undergoing surgery during the COVID-19 outbreak. The elective pathway included telephone surveys and a quantitative polymerase-chain-reaction test (RT-PCR) only for patients who were asymptomatic and at low risk of infection. Only patients with negative screening underwent surgery. In the non-elective pathway, preoperative screening was performed during the hospital admission. RESULTS: Among 835 patients considered for the elective pathway, 725 had negative RT-PCR results and underwent surgery. This reflects an 83% reduction in surgical activity from 2019. Moreover, 596 patients underwent non-elective surgery, representing a 28% reduction. Preoperatively, 39 patients (6.5%) tested positive for SARS-CoV-2 and underwent surgery through the non-elective pathway, vs. none in the elective pathway (p < 0.001). Postoperatively, 1.4% of elective surgery patients and 2.2% of non-elective surgery patients tested positive (p > 0.05). Mortality was higher in non-elective surgery (0.6% vs. 2.9%, p < 0.001) and in patients with COVID-19 (0% vs. 14%, p < 0.001). CONCLUSIONS: The low incidence of COVID-19 in elective surgeries during the outbreak demonstrates the importance and effectiveness of preoperative screening, combining surveys and RT-PCR.

Effects on cerebral blood flow of position changes, hyperoxia, CO2 partial pressure variations and the Valsalva manoeuvre: A study in healthy volunteers.

BACKGROUND: Maintaining adequate blood pressure to ensure proper cerebral blood flow (CBF) during surgery is challenging. Induced mild hypotension, sitting position or unavoidable intra-operative circumstances such as haemorrhage, added to variations in carbon dioxide and oxygen tensions, may influence perfusion. Several of these circumstances may coincide and it is unclear how these may affect CBF. OBJECTIVE: To describe the variation in transcranial Doppler and regional cerebral oxygen saturation (rSO2), as a surrogate of CBF, after cardiac preload and gravitational positional changes. DESIGN: Observational study. SETTING: Operating room at Hospital Clínic de Barcelona. VOLUNTEERS: Ten healthy volunteers, white, both sexes. INTERVENTIONS: Measurements were performed in the supine, sitting and standing positions during hyperoxia, hypocapnia and hypercapnia protocols and after a Valsalva manoeuvre. MAIN OUTCOME MEASURES: Cardiac index (CI), haemodynamic and respiratory variables, maximal and mean velocities (Vmax, Vmean) (transcranial Doppler) and rSO2 were acquired. Results were analysed using a generalised estimating equation technique. RESULTS: CI increases more than 16% after a preload challenge were not accompanied by differences in rSO2 or Vmax - Vmean. With positional changes, Vmean decreased more than 7% (P = 0.042) from the supine to the seated position. Hyperoxia induced a cerebral rSO2 increase more than 6% (P = 0.0001) with decreases in Vmax, Vmean and CI values more than 3% (P = 0.001, 0.022 and 0.001) in the supine and standing position. During hypocapnia, CI rose more than 20% from supine to seated and standing (P = 0.0001) with a 4.5% decrease in cerebral rSO2 (P = 0.001) and a decrease of Vmax - Vmean more than 24% in all positions (P = 0.001). Hypercapnia increased cerebral rSO2 more than 17% (P = 0.001), Vmax - Vmean more than 30% (P = 0.001) with no changes in CI. After a Valsalva manoeuvre, rSO2 decreased more than 3% in the right hemisphere in the upright position (P = 0.001). Vmax - Vmean decreased more than 10% (P = 0.001) with no changes in CI. CONCLUSION: CBF changes in response to cerebral vasoconstriction and vasodilatation were detected with rSO2 and transcranial Doppler in healthy volunteers during cardiac preload and in different body positions. Acute hypercapnia had a greater effect on recorded brain parameters than hypocapnia.

Experience with "Fast track" postoperative care after deep brain stimulation surgery.

BACKGROUND: A 24-h-stay in the post-anesthesia care unit (PACU) is a common postoperative procedure after deep brain stimulation surgery (DBS). OBJECTIVE: We evaluated the impact of a fast-track (FT) postoperative care protocol. METHODS: An analysis was performed on all patients who underwent DBS in 2 periods: 2006, overnight monitored care (OMC group), and 2007-2013, FT care (FT group). RESULTS: The study included 19 patients in OMC and 95 patients in FT. Intraoperative complications occurred in 26.3% patients in OMC vs. 35.8% in FT. Post-operatively, one patient in OMC developed hemiparesis, and agitation in 2 patients. In FT, two patients with intraoperative hemiparesis were transferred to the ICU. While on the ward, 3 patients from the FT developed hemiparesis, two of them 48h after the procedure. Thirty eight percent of FT had an MRI scan, while the remaining 62% and all patients of OMC had a CT-scan performed on their transfer to the ward. One patient in OMC had a subthalamic hematoma. Two patients in FT had a pallidal hematoma, and 3 a bleeding along the electrode. CONCLUSIONS: A FT discharge protocol is a safe postoperative care after DBS. There are a small percentage of complications after DBS, which mainly occur within the first 6h.

Anaesthetic and ICU management of aneurysmal subarachnoid haemorrhage: a survey of European practice.

BACKGROUND: Many aspects of the perioperative management of aneurysmal subarachnoid haemorrhage (SAH) remain controversial. It would be useful to assess differences in the treatment of SAH in Europe to identify areas for improvement. OBJECTIVE: To determine the clinical practice of physicians treating SAH and to evaluate any discrepancy between practice and published evidence. DESIGN: An electronic survey. PARTICIPANTS: Physicians identified through each national society of neuroanaesthesiology and neurocritical care. INTERVENTIONS: A 31-item online questionnaire was distributed by the ENIG group. Questions were designed to investigate anaesthetic management of SAH and diagnostic and treatment approaches to cerebral vasospasm. The survey was available from early October to the end of November 2012. RESULTS: Completed surveys were received from 268 respondents, of whom 81% replied that aneurysm treatment was conducted early (within 24 h). Sixty-five percent of centres treated more than 60% of SAH by coiling, 19% had high-volume clipping (>60% of aneurysms clipped) and 16% used both methods equally. No clear threshold for arterial blood pressure target was identified during coiling, temporary clipping or in patients without vasospasm after the aneurysm had been secured. Almost all respondents used nimodipine (97%); 21% also used statins and 20% used magnesium for prevention of vasospasm. A quarter of respondents used intra-arterial vasodilators alone, 5% used cerebral angioplasty alone and 48% used both endovascular methods to treat symptomatic vasospasm. In high-volume clipping treatment centres, 58% of respondents used endovascular methods to manage vasospasm compared with 86% at high-volume coiling treatment centres (P < 0.001). The most commonly used intra-arterial vasodilator was nimodipine (82%), but milrinone was used by 23% and papaverine by 19%. More respondents (44%) selected 'triple-H' therapy over hypertension alone (30%) to treat vasospasm. CONCLUSION: We found striking variability in the practice patterns of European physicians involved in early treatment of SAH. Significant differences were noted among countries and between high and low-volume coiling centres.

[Diagnostic yield and postoperative management of patients submitted to brain biopsy in a university hospital]. / Eficacia diagnóstica y manejo posoperatorio de los pacientes sometidos a biopsia cerebral en un hospital universitario.

OBJECTIVE: To assess the diagnostic yield and the incidence of perioperative complications in patients undergoing an open or closed cerebral biopsy and to determine the length of intensive care monitoring, for early diagnosis and fast management of perioperative complications. MATERIAL AND METHOD: This was a retrospective analysis of all the patients that underwent brain biopsy between January 2006 and July 2012. We recorded demographic data, comorbidities, modality of biopsy, intraoperative clinical data, histological results, computed tomography scanning findings and occurrence, and type of perioperative complications and moment of appearance. RESULTS: Seventy-six brain biopsies in 75 consecutive patients (51 closed and 25 open) were analysed. Diagnostic yield was 98% for closed biopsies and 96% for open biopsies. Mortality related to the procedures was 3.9 and 4%, respectively. The incidence of major complications was 3.9% for closed biopsies and 8% for open biopsies; half of these appeared within the first 24 postoperative hours, during patient stay in the Intensive Care Unit. Age was the only risk factor for complications (P=.04) in our study. No differences in morbimortality were found between the studied groups. CONCLUSIONS: Diagnostic yield was very high in our series. Because the importance of early diagnosis of complications for preventing long-term sequelae, we recommend overnight hospital stay for observation after open or closed brain biopsy.

Relationship between intraoperative regional cerebral oxygen saturation trends and cognitive decline after total knee replacement: a post-hoc analysis.

BACKGROUND: Bilateral regional brain oxygen saturation (rSO2) trends, reflecting intraoperative brain oxygen imbalance, could warn of brain dysfunction. Various types of cognitive impairment, such as memory decline, alterations in executive function or subjective complaints, have been described three months after surgery. Our aim was to explore the potential utility of rSO2 values as a warning sign for the development of different types of decline in postoperative psychological function. METHODS: Observational post-hoc analysis of data for the patient sample (n = 125) of a previously conducted clinical trial in patients over the age of 65 years undergoing total knee replacement under spinal anesthesia. Demographic, hemodynamic and bilateral rSO2 intraoperative values were recorded. An absolute rSO2 value of <50% or a reduction of >20% or >25% below baseline were chosen as relevant cutoffs. Composite function test scores were created from baseline to three months for each patient and adjusted for the mean (SD) score changes for a control group (n = 55). Tests were used to assess visual-motor coordination and executive function (VM-EF) (Wechsler Digit Symbol-Coding and Visual Reproduction, Trail Making Test) and memory (Auditory Verbal Learning, Wechsler Memory Scale); scales were used to assess psychological symptoms. RESULTS: We observed no differences in baseline rSO2 values; rSO2 decreased significantly in all patients during surgery (P < 0.0001). Seventy-five patients (60%) had no sign of cognitive decline or psychological symptoms. Twenty-one patients (16.8%) had memory decline, 3 (2.4%) had VM-EF decline, and 33 (26.4%) had psychological symptoms. Left and right rSO2 values were asymmetric in patients who had memory decline (mean [SD] left-right ratio of 95.03 [8.51] vs 101.29 [6.7] for patients with no changes, P = 0.0012). The mean right-left difference in rSO2 was also significant in these patients (-2.87% [4.73%], lower on the right, P = 0.0034). CONCLUSIONS: Detection of a trend to asymmetry in rSO2 values can warn of possible postoperative onset of memory decline. Psychological symptoms and memory decline were common three months after knee replacement in our patients over the age of 65 years.

Craniotomy in sitting position: anesthesiology management.

PURPOSE OF REVIEW: Sitting position to surgically approach posterior fossa disorder continues to be the first choice for some neurosurgical teams. We underwent a literature research for recent published studies involving neurosurgical patients operated on in this position. Preoperative evaluation, anesthetic technique, intraoperative monitoring, detection and treatment of venous or arterial air embolism episodes, and all the reported complications were recorded. RECENT FINDINGS: A modified semisitting (lounging) position aiming to create a positive pressure in the transverse and sigmoid sinuses, with lower head and higher legs positioned above the top of the head, decreases the incidence and severity of venous air embolism. Hyperventilation, compromising cerebral blood flow, has to be avoided during a sitting position. Precordial Doppler or transesophageal echocardiography monitoring improves the detection of small venous air embolism enabling its early treatment and diminishing its consequences. Patients with known patent foramen ovale can be operated on in a sitting position, under strict protocol, with few reported clinical venous air embolism and no paradoxical air embolism. SUMMARY: Sitting position for neurosurgical procedures may be a well tolerated approach for the patient if neurosurgeons and neuroanesthesiologists undergo a strict team protocol, including all necessary monitoring and meticulously followed.

[Detection of venous air embolism and patent foramen ovale in neurosurgery patients in sitting position]. / Detección de embolismo aéreo venoso y de foramen oval permeable en pacientes neuroquirúrgicos intervenidos en posición de sedestación.

INTRODUCTION: Early detection of venous air embolism (VAE) during neurosurgical procedures in sitting position decreases the severity of its complications. OBJECTIVES: our aim was to analyse the detection of VAE and its impact on patients operated in a sitting position, verify air aspiration through a central venous catheter and assess the feasibility of the routine use of transcranial Doppler (TCD) for intraoperative diagnosis of patent foramen ovale (PFO). MATERIAL AND METHODS: We performed a prospective study of consecutive neurosurgical procedures performed in the sitting position for 5 years. Precordial Doppler and end-tidal carbon dioxide were the diagnostic methods for VAE. PFO was explored by TCD after anaesthetic induction. RESULTS: 136 patients were operated in the sitting position, 93 craniotomies and 43 cervical spine procedures. Twenty-two patients (16.2%) were diagnosed with VAE (21.5% of craniotomies and 4.7% of spinal surgeries; p=.013). In 59% of cases, air was aspirated through the central venous catheter. There was haemodynamic involvement in 3 patients, impaired oxygenation in 4 and clinically relevant pneumocephalus in 5 of them. Two patients (1.4%) were diagnosed with PFO, but did not present episodes of VAE or paradoxical air embolism. CONCLUSIONS: The series analysed confirmed a higher incidence of VAE in craniotomies than in cervical spine surgery in a sitting position. We were able to aspirate air through the central venous catheter in more than half the cases. No patients suffered critical intraoperative complications following our approach. The low incidence of PFO detected with TCD will imply a modification of our protocol performed on anaesthetised patients.

Transcranial Doppler pulsatility index: what it is and what it isn't.

BACKGROUND: Transcranial Doppler (TCD) pulsatility index (PI) has traditionally been interpreted as a descriptor of distal cerebrovascular resistance (CVR). We sought to evaluate the relationship between PI and CVR in situations, where CVR increases (mild hypocapnia) and decreases (plateau waves of intracranial pressure-ICP). METHODS: Recordings from patients with head-injury undergoing monitoring of arterial blood pressure (ABP), ICP, cerebral perfusion pressure (CPP), and TCD assessed cerebral blood flow velocities (FV) were analyzed. The Gosling pulsatility index (PI) was compared between baseline and ICP plateau waves (n = 20 patients) or short term (30-60 min) hypocapnia (n = 31). In addition, a modeling study was conducted with the "spectral" PI (calculated using fundamental harmonic of FV) resulting in a theoretical formula expressing the dependence of PI on balance of cerebrovascular impedances. RESULTS: PI increased significantly (p < 0.001) while CVR decreased (p < 0.001) during plateau waves. During hypocapnia PI and CVR increased (p < 0.001). The modeling formula explained more than 65% of the variability of Gosling PI and 90% of the variability of the "spectral" PI (R = 0.81 and R = 0.95, respectively). CONCLUSION: TCD pulsatility index can be easily and quickly assessed but is usually misinterpreted as a descriptor of CVR. The mathematical model presents a complex relationship between PI and multiple haemodynamic variables.

Bilateral Bispectral Index Monitoring Performance in the Detection of Seizures in Nonanesthetized Epileptic Patients: An Observational Study.

BACKGROUND: The aim of this observational study was to determine whether bilateral bispectral index (BIS) monitoring can detect seizures in epileptic patients. METHODS: Four-channel frontal BIS monitoring and standard 40-channel electroencephalography monitoring were conducted in epileptic patients undergoing evaluation for epilepsy surgery. The BIS numerical value, signal quality index, electromyography, suppression ratio, and color density spectral array were continuously recorded. In patients with electroencephalography-confirmed seizures, the mean value and trend (slope of linear regression) of bilateral BIS monitor parameters were analyzed from 1 minute before to 1 minute after seizure onset. RESULTS: Of 48 patients included in the study, 21 (43.8%) had at least 1 seizure. BIS numerical value was not able to detect focal or focal to bilateral tonic-clonic seizures. Considering all seizures, the only significant differences between recordings 1 minute before and 1 minute after seizure onset were a decrease in the signal quality index slope from 1 hemisphere (0.039±0.297 vs. -0.085±0.321, respectively; P =0.029) and in the mean signal quality index recorded from both hemispheres (left hemisphere: 65.775±30.599 vs. 61.032±26.285; P =0.016 and right hemisphere: 63.244±31.985 vs. 59.837±27.360; 0.029); these differences were not maintained after Hochberg adjustment for multiple comparisons. In seizures occurring during sleep, there was a change in the electromyography slope of 1 hemisphere before and after seizure onset (-0.141±0.176 vs. 0.162±0.140, respectively; P =0.038). There were variable responses in BIS parameters in the 3 patients who developed focal nonconvulsive seizure clusters. CONCLUSION: Bilateral BIS monitoring was not able to detect the occurrence of seizures in epileptic patients.

Association between preoperative serum lactate concentrate with tumor cell proliferative index in primary brain tumor.

BACKGROUND: Elevated preoperative lactate levels have been reported in patients admitted for resection of brain tumors. As histologic type and tumor grade have also been linked to lactate concentration, we hypothesized that preoperative lactate concentration in patients with brain tumors may be associated with tumor proliferation. We describe the relationship between preoperative plasma lactate levels, and the cell proliferation marker Ki-67 in brain tumor surgery. METHODS: In this cross-sectional study, records of patients who underwent craniotomy between June 2017 and February 2018 at our Hospital were reviewed to select glioma and meningioma cases in which lactate concentrations in plasma and degree of cell proliferation were registered. Bivariable and linear regression analyses were used to assess the association between lactate concentrations and the Ki-67 Index. RESULTS: Lactate concentrations in plasma and Ki-67 Index were available in 55 patients. Meningioma cases had a mean concentration of 1.2 (0.1) mmol/L compared to diffuse astrocytic and oligodendroglial tumors cases with 1.7 (0.1) mmol/L (P<0.01). Both variables had a low positive correlation in meningiomas (Spearman's r, 0.29; 95% CI, -0.10-0.61; P=0.13) and a high correlation in gliomas (Spearman's r, 0.64; 95% CI, 0.33-0.82; P<0.01). The pooled analysis showed a high correlation index (Spearman's r, 0.61; 95% CI, 0.40-0.76; P<0.01). A linear regression model showed that the Ki-67 Index explained 43% of the variation in lactate (P<0.01). CONCLUSIONS: Brain tumors with higher rates of cell proliferation have higher plasma lactate levels. In this scenario, lactate concentrations may not only reflect systemic perfusion.

Use of second generation supraglottic airway device for endovascular treatment of unruptured intracranial aneurysms: a retrospective cohort.

BACKGROUND: We aimed to assess the feasibility of using supraglottic devices as an alternative to orotracheal intubation for airway management during anesthesia for endovascular treatment of unruptured intracranial aneurisms in our department over a nine-year period. METHODS: Retrospective single center analysis of cases (2010-2018). Primary outcomes: airway management (supraglottic device repositioning, need for switch to orotracheal intubation, airway complications). SECONDARY OUTCOMES: aneurysm complexity, history of subarachnoid hemorrhage, hemodynamic monitoring, and perioperative complications. RESULTS: We included 187 patients in two groups: supraglottic device 130 (69.5%) and orotracheal intubation 57 (30.5%). No adverse incidents were recorded in 97% of the cases. Three supraglottic device patients required supraglottic device repositioning and 1 supraglottic device patient required orotracheal intubation due to inadequate ventilation. Three orotracheal intubation patients had a bronchospasm or laryngospasm during awakening. Forty-five patients (24.1%) had complex aneurysms or a history of subarachnoid hemorrhage. Thirty-three of them (73.3%) required orotracheal intubation compared to 24 of the 142 (16.9%) with non-complex aneurysms. Two patients in each group died during early postoperative recovery. Two in each group also had intraoperative bleeding. A post-hoc analysis showed that orotracheal intubation was used in 55 patients (44%) in 2010 through 2014 and 2 (3.2%) in 2015 through 2018, parallel to a trend toward less invasive blood pressure monitoring from the earlier to the later period from 34 (27.2%) cases to 5 (8.2%). CONCLUSION: Supraglottic device, like other less invasiveness protocols, can be considered a feasible alternative airway management approach in selected patients proposed for endovascular treatment of unruptured intracranial aneurisms.

Hemodynamic Response, Coughing and Incidence of Cerebrospinal Fluid Leakage on Awakening with an Endotracheal Tube or Laryngeal Mask Airway in Place after Transsphenoidal Pituitary Surgery: A Randomized Clinical Trial.

We aimed to compare systemic and cerebral hemodynamics and coughing during emergence after pituitary surgery after endotracheal tube (ETT) extubation or after replacing ETT with a laryngeal mask airway (LMA). Patients were randomized to awaken with an ETT in place or after replacing it with an LMA. We recorded mean arterial pressure (MAP), heart rate, middle cerebral artery (MCA) flow velocity, regional cerebral oxygen saturation (SrO2), cardiac index, plasma norepinephrine, need for vasoactive drugs, coughing during emergence, and postoperative cerebrospinal fluid (CSF) leakage. The primary endpoint was postoperative MAP; secondary endpoints were SrO2 and coughing incidence. Forty-five patients were included. MAP was lower during emergence than at baseline in both groups. There were no significant between-group differences in blood pressure, nor in the number of patients that required antihypertensive drugs during emergence (ETT: 8 patients (34.8%) vs. LMA: 3 patients (14.3%); p = 0.116). MCA flow velocity was higher in the ETT group (e.g., mean (95% CI) at 15 min, 103.2 (96.3-110.1) vs. 89.6 (82.6-96.5) cm·s-1; p = 0.003). SrO2, cardiac index, and norepinephrine levels were similar. Coughing was more frequent in the ETT group (81% vs. 15%; p < 0.001). CSF leakage occurred in three patients (13%) in the ETT group. Placing an LMA before removing an ETT during emergence after pituitary surgery favors a safer cerebral hemodynamic profile and reduces coughing. This strategy may lower the risk for CSF leakage.

Combination of diffusion tensor and functional magnetic resonance imaging during recovery from the vegetative state.

BACKGROUND: The rate of recovery from the vegetative state (VS) is low. Currently, little is known of the mechanisms and cerebral changes that accompany those relatively rare cases of good recovery. Here, we combined functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI) to study the evolution of one VS patient at one month post-ictus and again twelve months later when he had recovered consciousness. METHODS: fMRI was used to investigate cortical responses to passive language stimulation as well as task-induced deactivations related to the default-mode network. DTI was used to assess the integrity of the global white matter and the arcuate fasciculus. We also performed a neuropsychological assessment at the time of the second MRI examination in order to characterize the profile of cognitive deficits. RESULTS: fMRI analysis revealed anatomically appropriate activation to speech in both the first and the second scans but a reduced pattern of task-induced deactivations in the first scan. In the second scan, following the recovery of consciousness, this pattern became more similar to that classically described for the default-mode network. DTI analysis revealed relative preservation of the arcuate fasciculus and of the global normal-appearing white matter at both time points. The neuropsychological assessment revealed recovery of receptive linguistic functioning by 12-months post-ictus. CONCLUSIONS: These results suggest that the combination of different structural and functional imaging modalities may provide a powerful means for assessing the mechanisms involved in the recovery from the VS.

Anaesthesia for endoscopic neurosurgical procedures.

PURPOSE OF REVIEW: Endoscopic neurosurgical procedures are becoming more frequent and popular in the treatment of intracranial disease. When endoscopy involves the intraventricular structures, irrigating solutions are required and may contribute to sudden and sharp increases in intracranial pressure. More recently, nasal endoscopic approach has been used to perform skull base surgery for aneurysms and tumours. We have analysed published articles in order to detect anaesthesia management and perioperative complications. RECENT FINDINGS: Sudden and dangerously low decreases in cerebral perfusion pressures do not provoke the 'traditional Cushing's response' usually associated with significantly high intracranial pressure. It is important to note that tachycardia (not bradycardia) and/or hypertension are the most frequent haemodynamic complications during neuroendoscopic procedures. With the transnasal approach severe intraoperative haemorrhage is the most important complication to consider followed by direct injury to surrounding neural structures. SUMMARY: Invasive arterial blood pressure and intracranial pressure should be measured continuously during neuroendoscopies to detect early intraoperative cerebral ischaemia instead of waiting for the appearance of bradycardia which may be a late sign. General anaesthesia remains the technique of choice. Intracranial haemorrhage increases the likelihood of perioperative complications. Close postoperative monitoring is required to diagnose and treat complications such as convulsions, persistent hydrocephalus, haemorrhage or electrolytic imbalance.