Comparison of remifentanil and fentanyl in patients undergoing craniotomy for supratentorial space-occupying lesions

Effects of an Early Intensive Blood Pressure-lowering Strategy Using Remifentanil and Dexmedetomidine in Patients with Spontaneous Intracerebral Hemorrhage: A Multicenter, Prospective, Superiority, Randomized Controlled Trial

BACKGROUND

Although it has been established that elevated blood pressure and its variability worsen outcomes in spontaneous intracerebral hemorrhage, antihypertensives use during the acute phase still lacks robust evidence. A blood pressure-lowering regimen using remifentanil and dexmedetomidine might be a reasonable therapeutic option given their analgesic and antisympathetic effects. The objective of this superiority trial was to validate the efficacy and safety of this blood pressure-lowering strategy that uses remifentanil and dexmedetomidine in patients with acute intracerebral hemorrhage.

METHODS

In this multicenter, prospective, single-blinded, superiority randomized controlled trial, patients with intracerebral hemorrhage and systolic blood pressure (SBP) 150 mmHg or greater were randomly allocated to the intervention group (a preset protocol with a standard guideline management using remifentanil and dexmedetomidine) or the control group (standard guideline-based management) to receive blood pressure-lowering treatment. The primary outcome was the SBP control rate (less than 140 mmHg) at 1 h posttreatment initiation. Secondary outcomes included blood pressure variability, neurologic function, and clinical outcomes.

RESULTS

A total of 338 patients were allocated to the intervention (n = 167) or control group (n = 171). The SBP control rate at 1 h posttreatment initiation in the intervention group was higher than that in controls (101 of 161, 62.7% vs. 66 of 166, 39.8%; difference, 23.2%; 95% CI, 12.4 to 34.1%; P < 0.001). Analysis of secondary outcomes indicated that patients in the intervention group could effectively reduce agitation while achieving lighter sedation, but no improvement in clinical outcomes was observed. Regarding safety, the incidence of bradycardia and respiratory depression was higher in the intervention group.

CONCLUSIONS

Among intracerebral hemorrhage patients with a SBP 150 mmHg or greater, a preset protocol using a remifentanil and dexmedetomidine-based standard guideline management significantly increased the SBP control rate at 1 h posttreatment compared with the standard guideline-based management.

EDITOR’S PERSPECTIVE

Intraoperative application of low-dose dexmedetomidine or lidocaine for postoperative analgesia in pediatric patients following craniotomy: a randomized double-blind placebo-controlled trial

Background

Postoperative pain is a common occurrence in pediatric patients following craniotomy, often leading to negative outcomes. Intravenous dexmedetomidine and lidocaine are commonly used adjuvant medicines in general anesthesia to reduce perioperative opioid consumption and relieve postoperative pain in adults. While they show promise for use in pediatrics, the evidence of their application in pediatric craniotomy patients is limited. Therefore, we aimed to compare the effects of dexmedetomidine and lidocaine on postoperative pain in pediatric patients following craniotomy.

Methods

We conducted a randomized, double-blind, single-center trial on children scheduled for craniotomy. The 255 recruited participants aged 1-12 years were randomly assigned to intraoperatively receive a loading intravenous dose of either dexmedetomidine 1 μg·kg-1 or lidocaine 2 mg·kg-1 or normal saline for 15 min followed by dexmedetomidine 0.5 μg·kg-1·h-1 or lidocaine 1 mg·kg-1·h-1 or normal saline until the sutures of endocranium were completed. The primary outcome was the cumulative sufentanil consumption within 24 h post-surgery.

Results

A total of 241 patients were included in the statistical analysis. The primary outcome did not show any significant differences among the three groups (median (IQR) lidocaine group: 3.36 (1.32-5.64) μg vs. dexmedetomidine group: 3.12 (1.36-6.39) μg vs. control group 3.46 (1.77-7.62) μg, p = 0.485). Among the secondary outcomes, there was a statistically significant but small reduction in sufentanil consumption within 2 h, postoperative FLACC/WBFS/NRS pain scores within 4 h after surgery and postoperative Ramsay sedation scores in dexmedetomidine group (p < 0.05). Regarding postoperative complications, the incidence of electrolyte disturbance within 24 and 48 h after surgery was significantly higher in control group compared to the other two groups. There were no significant differences in intraoperative opioid consumption, postoperative frequency of remedy medication, or length of hospitalization among the three groups. No adverse events related to lidocaine or dexmedetomidine were observed.

Conclusions

There were no significant differences in the primary outcome among the three groups. Although dexmedetomidine showed some benefits in reducing postoperative opioid consumption within the first 2 h and pain intensity within the first 4 h post-surgery, these findings should be interpreted with caution. Further research is required to comprehensively assess the outcomes and determine the optimal administration strategy.

Clinical Trial Registration

[http://www.chictr.org.cn/index.aspx], identifier [ChiCTR1800019411].

Ultrasound-guided superficial cervical plexus block reduces opioid consumption in patients undergoing craniotomy via suboccipital retrosigmoid approach: a randomized controlled trial

INTRODUCTION

The effectiveness of superficial cervical plexus block (SCPB) at decreasing opioid use and improving hemodynamic stability during suboccipital retrosigmoid craniotomy has not been established. The aim of this study is to evaluate the analgesic effect of preoperative ultrasound-guided SCPB for craniotomy via a suboccipital retrosigmoid approach.

METHODS

This was a prospective, single-center, randomized, double-blind, parallel-group controlled trial. One hundred and six adult patients undergoing suboccipital retrosigmoid craniotomy were randomly allocated into either the SCPB group (n=53) to receive 10 mL of 0.5% ropivacaine or the control group (n=53) to receive 0.9% normal saline injected into the superficial layer of prevertebral fascia guided by ultrasound. The primary outcome was the cumulative consumption of sufentanil with patient-controlled intravenous analgesia (PCIA) within 24 hours. Secondary outcomes included the overall perioperative consumption of opioids, the area under the curve of the pain score from 1 hour to 48 hours (AUC1-48), intraoperative hemodynamic parameters, and anesthesia depth.

RESULTS

The mean PCIA pump cumulative consumption of sufentanil in the first 24 hour postoperative period was significantly lowered by SCPB (5.0 µg vs 9.8 µg, 95% CI: -8.0 to -2.4; p=0.001). The total perioperative consumption of sufentanil (45.0 µg vs 54.5 µg, 95% CI: -14.8 to -4.1; p=0.001) was also significantly decreased by SCPB. The incidence of severe pain within 24 hours was decreased by SCPB (7.5% vs 26.4%, p=0.01). SCPB significantly decreased the AUC1-48 of the pain score. Intraoperative hemodynamic parameters and anesthesia depth were similar between groups (p>0.05).

DISCUSSION

SCPB provides effective analgesia in patients undergoing craniotomy and tumor resection via suboccipital retrosigmoid approach. SCPB demonstrates an opioid-sparing effect and allows for the maintenance hemodynamic stability at an appropriate depth of anesthesia.

TRIAL REGISTRATION NUMBER

NCT04036812.

Dexmedetomidine vs. lidocaine for postoperative analgesia in pediatric patients undergoing craniotomy: a protocol for a prospective, randomized, double-blinded, placebo-controlled trial

Background

Postoperative pain is a common problem that occurs in pediatric patients following neurosurgery which may lead to severe complications. Dexmedetomidine is a commonly used adjuvant medicine in craniotomy owing to its sedative, amnestic, analgesic, and neuroprotective properties. Besides, studies suggest that lidocaine has similar effects on sedation, analgesia, and neuroprotection. Both two adjuvants can reduce postoperative pain after neurosurgery in adults. However, it is still unknown whether dexmedetomidine or lidocaine can reduce postoperative pain in children undergoing craniotomy, and if yes, which is a better medicine choice. Therefore, we aimed to compare the effect of dexmedetomidine vs. lidocaine on postoperative pain in pediatric patients after craniotomy.

Methods/design

We will perform a randomized (1:1:1), double-blind, placebo-controlled, single-center trial. Children aged 1–12 years scheduled for craniotomy will be eligible for inclusion. The 255 recruited participants will be stratified by age in two strata (1–6 years and 7–12 years), and then each stratum will be equally randomized to three groups: group D (infusion of dexmedetomidine [intervention group]), group L (infusion of lidocaine [intervention group]), and group C (infusion of normal saline [control group]). Patients will be followed up at 1 h, 2 h, 4 h, 24 h, and 48 h after surgery. The primary outcome will be total sufentanil consumption within 24 h after surgery.

Discussion

In this clinical trial, we expect to clarify and compare the postoperative analgesic effect of dexmedetomidine vs. lidocaine infusion on pediatric patients undergoing craniotomy. We believe that the results of this trial will provide more choices for postoperative analgesia for the pediatric population.

Trial registration

Chinese ClinicalTrials.gov ChiCTR1800019411. Registered on 10 November 2018

Perioperative Management of Aneurysmal Subarachnoid Hemorrhage

Aneurysmal subarachnoid hemorrhage is an acute neurologic emergency. Prompt definitive treatment of the aneurysm by craniotomy and clipping or endovascular intervention with coils and/or stents is needed to prevent rebleeding. Extracranial manifestations of aneurysmal subarachnoid hemorrhage include cardiac dysfunction, neurogenic pulmonary edema, fluid and electrolyte imbalances, and hyperglycemia. Data on the impact of anesthesia on long-term neurologic outcomes of aneurysmal subarachnoid hemorrhage do not exist. Perioperative management should therefore focus on optimizing systemic physiology, facilitating timely definitive treatment, and selecting an anesthetic technique based on patient characteristics, severity of aneurysmal subarachnoid hemorrhage, and the planned intervention and monitoring. Anesthesiologists should be familiar with evoked potential monitoring, electroencephalographic burst suppression, temporary clipping, management of external ventricular drains, adenosine-induced cardiac standstill, and rapid ventricular pacing to effectively care for these patients.

Dexmedetomidine Reduces Perioperative Opioid Consumption and Postoperative Pain Intensity in Neurosurgery: A Meta-analysis

BACKGROUND

Dexmedetomidine (DEX) has been administered to patients during neurosurgery. Some studies have found that DEX could reduce perioperative opioid consumption and postoperative pain intensity. However, no firm conclusions have been reached. The purpose of this meta-analysis was to assess the efficacy of DEX for managing pain in neurosurgical patients.

MATERIALS AND METHODS

A comprehensive literature review was conducted to identify randomized controlled trials (RCTs) focusing on the effects of DEX on perioperative opioid consumption and postoperative pain intensity in patients undergoing neurosurgery. PubMed, the Web of science, the Cochrane Library, and Scopus were searched. The resulting data were combined to calculate the pooled mean differences (MDs), standard MDs or odds ratios (ORs), and 95% confidence intervals (CIs), as appropriate. Heterogeneity and potential publication bias were assessed. Furthermore, a trial sequential analysis was performed to improve the precision of our findings.

RESULTS

A total of 11 published RCTs involving 674 patients undergoing neurosurgery (335 patients, 339 controls) were included in this meta-analysis. There were significant differences in postanesthesia care unit (PACU) visual analog scale scores between the groups (MD=-1.54, 95% CI, -2.33 to 0.75, I=87%, P=0.0001). In addition, there were significant differences in PACU opioid requirements between the treatment and control groups (standard MD=-0.88, 95% CI, -1.74 to 0.02, I=91%, P=0.05). Furthermore, intraoperative opioid consumption was significantly reduced in the treatment group (MD=-127.75, 95% CI, -208.62 to 46.89, I=98%, P=0.002).

CONCLUSIONS

DEX could reduce perioperative and PACU opioid consumption as well as postoperative pain intensity.

Application of remifentanil for conscious sedation and analgesia in short-term ERCP and EST surgery

This study aims to observe and evaluate the use of remifentanil in conscious sedation and analgesia for the safety and comfort of patients undergoing short-term endoscopic retrograde cholangiopancreatography (ERCP) and endoscopic sphincterotomy (EST).Sixty-eight patients who underwent ERCP and EST were randomly divided into two groups: research group and control group. Patients in the research group were intravenously injected with remifentanil (80-2/3* age) for 1 to 2 minutes, combined with the intravenous injection of propofol (20-30 mg) during the course of treatment. ERCP surgery was performed when Ramsay sedation scale (RSS) score reached 2-3. During the surgery, patients were closely monitored for cough symptoms, aspiration, and respiratory and circulatory system performance, and timely treatment was performed. Sedative drugs were not given in patients in the control group.In research group, the circulatory and respiratory depression of patients was mild, only one patient needed to be treated, and there was no arrhythmia requiring treatment. Five patients had respiratory depression (blood oxygen saturation decreased to <90%), which was immediately corrected. There were no interruptions during surgery due to body movement, cough, or aspiration.The use of remifentanil for conscious sedation and analgesia can be broadly applied in short-term ERCP, which greatly improves patient comfort during the surgery. This approach may bear promise for a widespread use in future clinical practice.

Safety of remifentanil in transsphenoidal surgery: A single-center analysis of 540 patients

Although some studies have examined the efficacy and safety of remifentanil in patients undergoing neurosurgical procedures, none has examined its safety in transsphenoidal operations specifically. In this study, all transsphenoidal operations performed by a single author from 2008 to 2015 were retrospectively reviewed to evaluate the safety of remifentanil in a consecutive series of patients. During the study period, 540 transsphenoidal operations were identified. Of these, 443 (82.0%) patients received remifentanil intra-operatively; 97 (18.0%) did not. The two groups were well-matched with regard to demographic categories, comorbidities, and pre-operative medications (p>0.05), except pre-operative tobacco use (p=0.021). Patients were also well-matched with regard to radiographic features and surgical techniques. Patients who received remifentanil were more likely to harbor a macroadenoma (78.1% vs. 67.0%, p=0.025), and had slightly longer anesthesia time on average (269.2minvs. 239.4min, p=0.024). All pathologic diagnoses were well-matched between the two groups, except that patients receiving remifentanil were more likely to harbor a non-functioning adenoma (46.5% vs. 26.8%, p<0.001). Analysis of post-operative complications showed no significant difference between patients who received remifentanil and those who did not, and length of stay and prevalence of ICU stay did not differ between the two groups. In a well-matched series of 540 patients undergoing transsphenoidal surgery, remifentanil was found to be a safe anesthetic adjunct. There were no significant differences in post-operative hospital course or complications in patients who did and did not receive intra-operative remifentanil.

Management of Elevated Intracranial Pressure

Elevated intracranial pressure (ICP) is a primary cause of morbidity and mortality for many neurologic disorders. The relationship between ICP and brain volume is influenced by autoregulatory processes that can become dysfunctional. As a result, neurologic damage can occur by systemic and intracranial insults such as ischemia and excitatory amino acids. Therefore, survival is dependent on optimizing ICP and cerebral perfusion pressure. Treatment of intracranial hypertension requires intensive monitoring and aggressive therapy. Intracranial pressure monitoring techniques such as intraventricular catheters are useful for determining ICP elevations before changes in vital signs and neurologic status. Therapeutic modalities, generally aimed at reducing cerebral blood volume, brain tissue, and cerebrospinal fluid (CSF) volume, include nonpharmacologic (CSF removal, controlled hyperventilation, and elevating the patient’s head) and pharmacologic management. Mannitol and sedation are first-line agents used to lower ICP. Barbiturate coma may be beneficial in patients with elevated ICP refractory to conventional treatment. The use of prophylactic antiseizure therapy and optimal nutrition prevents significant complication. Currently, investigations are directed at discovering useful neuroprotective agents that prevent secondary neurologic injury.

Remifentanil in Combination With Propofol Is Suitable for Use in the Dental Outpatient Setting

Although several adjuncts to the general anesthetic propofol have been proposed, there is insufficient research identifying the ideal agent, and in what dosage, to combine with propofol in dental outpatient anesthesia. Here we examined the combination of remifentanil or nitrous oxide and propofol in patients with severe dental avoidance undergoing dental treatment in the outpatient setting. Eighty patients were randomized to 4 groups and administered propofol/saline solution (PS; n = 20), propofol/remifentanil 0.25 μg/kg/min (PRe-0.25; n = 20), propofol/remifentanil 0.125 μg/kg/min (PRe-0.125; n = 20), or propofol/66% nitrous oxide (PN; n = 20). During anesthesia, the bispectral index value was kept between 40 and 60. Body movements and hemodynamic changes during anesthesia, emergence, and recovery as well as anesthetic cost were compared between the combinations. Body movements were observed in all patients administered PS but in no patients administered PRe-0.25, PRe-0.125, or PN. Postoperative nausea was observed in 5 patients (25%) administered PRe-0.25 and in 1 patient (5%) administered PN. Although both PRe-0.125 and PN were useful clinically, PRe-0.125 was the least expensive combination.

Comparison of Dexmedetomidine and Remifentanil on Airway Reflex and Hemodynamic Changes during Recovery after Craniotomy

PURPOSE

During emergence from anesthesia for a craniotomy, maintenance of hemodynamic stability and prompt evaluation of neurological status is mandatory. The aim of this prospective, randomized, double-blind study was to compare the effects of dexmedetomidine and remifentanil on airway reflex and hemodynamic change in patients undergoing craniotomy.

MATERIALS AND METHODS

Seventy-four patients undergoing clipping of unruptured cerebral aneurysm were recruited. In the dexmedetomidine group, patients were administered dexmedetomidine (0.5 μg/kg) for 5 minutes, while the patients of the remifentanil group were administered remifentanil with an effect site concentration of 1.5 ng/mL until endotracheal extubation. The incidence and severity of cough and hemodynamic variables were measured during the recovery period. Hemodynamic variables, respiration rate, and sedation scale were measured after extubation and in the post-anesthetic care unit (PACU).

RESULTS

The incidence of grade 2 and 3 cough at the point of extubation was 62.5% in the dexmedetomidine group and 53.1% in the remifentanil group (p=0.39). Mean arterial pressure (p=0.01) at admission to the PACU and heart rate (p=0.04 and 0.01, respectively) at admission and at 10 minutes in the PACU were significantly lower in the dexmedetomidine group. Respiration rate was significantly lower in the remifentanil group at 2 minutes (p<0.01) and 5 minutes (p<0.01) after extubation.

CONCLUSION

We concluded that a single bolus of dexmedetomidine (0.5 μg/kg) and remifentanil infusion have equal effectiveness in attenuating coughing and hemodynamic changes in patients undergoing cerebral aneurysm clipping; however, dexmedetomidine leads to better preservation of respiration.

Dexmedetomidine as an Anesthetic Adjuvant in Patients Undergoing Transsphenoidal Resection of Pituitary Tumor

BACKGROUND

Transnasal transsphenoidal (TNTS) resection of pituitary tumors involves wide fluctuation in hemodynamic parameter and causes hypertension and tachycardia due to intense noxious stimuli during various stages of surgery. None of routinely used anesthetic agents effectively blunts the undesirable hemodynamic responses, and therefore usually there is a need to use increased doses of anesthetic agents. Dexmedetomidine (DEX) an α-2 adrenergic receptor agonist, because its sympatholytic and antinociceptive properties may ensure optimal intraoperative hemodynamic stability during critical moments of surgical manipulation. In addition, DEX reduced the anesthetic requirement with rapid recovery at the end of surgery. The main aim of our study was to evaluate the effect of DEX on perioperative hemodynamics, anesthetic requirements, and recovery characteristics in patients undergoing TNTS resection of pituitary tumors.

MATERIALS AND METHODS

Forty-six patients scheduled for elective TNTS resection of pituitary tumor were randomized to receive a continuous infusion of DEX (group D) or 0.9% saline (group C). Patients in both the groups were subjected to a standardized anesthesia comprising of induction with propofol, fentanyl, vecuronium, and positive pressure ventilation with O2/air (1:1)/isoflurane. The response entropy target range during maintenance of anesthesia was 40 to 60. The hemodynamic variables at various stages of surgery, intraoperative anesthetic, and analgesic and recovery characteristics were recorded.

RESULTS

Total fentanyl consumption during the study period was significantly lower in group D compared with group C (4.7 and 7.7 µg/kg, respectively; P<0.01). End-tidal isoflurane concentration requirement was found to be significantly reduced in group D compared with group C throughout the surgical period. Fentanyl and end-tidal isoflurane concentration requirement was reduced in group D compared with group C by 40% and 33.3%, respectively. Heart rate and mean arterial pressure were significantly higher in the group C compared with group D after intubation, during various stages of surgery and immediately after extubation. The group D had excellent surgical conditions and lesser bleeding in comparison to group C. Emergence time and extubation time were significantly shorter in group D compared with group C.

CONCLUSIONS

DEX as an anesthetic adjuvant improved hemodynamic stability and decreased anesthetic requirements in patients undergoing TNTS resection of pituitary tumor. In addition, DEX provided better surgical field exposure conditions and early recovery from anesthesia.

Options for perioperative pain management in neurosurgery

Moderate-to-severe pain following neurosurgery is common but often does not get attention and is therefore underdiagnosed and undertreated. Compounding this problem is the traditional belief that neurosurgical pain is inconsequential and even dangerous to treat. Concerns about problematic effects associated with opioid analgesics such as nausea, vomiting, oversedation, and increased intracranial pressure secondary to elevated carbon dioxide tension from respiratory depression have often led to suboptimal postoperative analgesic strategies in caring for neurosurgical patients. Neurosurgical patients may have difficulty or be incapable of communicating their need for analgesics due to neurologic deficits, which poses an additional challenge. Postoperative pain control should be a priority, because pain adversely affects recovery and patient outcomes. Inconsistent practices and the quality of current analgesic strategies for neurosurgical patients still leave room for improvement. Given the complexity of postoperative pain management for these patients, multimodal strategies are often required to optimize pain control and at the same time limit undesired side effects.

Effects of Anesthetic Management on Early Postoperative Recovery, Hemodynamics and Pain After Supratentorial Craniotomy

Various clinical trials have assessed how intraoperative anesthetics can affect early recovery, hemodynamics and nociception after supratentorial craniotomy. Whether or not the difference in recovery pattern differs in a meaningful way with anesthetic choice is controversial. This review examines and compares different anesthetics with respect to wake-up time, hemodynamics, respiration, cognitive recovery, pain, nausea and vomiting, and shivering. When comparing inhalational anesthetics to intravenous anesthetics, either regimen produces similar recovery results. Newer shorter acting agents accelerate the process of emergence and extubation. A balanced inhalational/intravenous anesthetic could be desirable for patients with normal intracranial pressure, while total intravenous anesthesia could be beneficial for patients with elevated intracranial pressure. Comparison of inhalational anesthetics shows all appropriate for rapid emergence, decreasing time to extubation, and cognitive recovery. Comparison of opioids demonstrates similar awakening and extubation time if the infusion of longer acting opioids was ended at the appropriate time. Administration of local anesthetics into the skin, and addition of corticosteroids, NSAIDs, COX-2 inhibitors, and PCA therapy postoperatively provided superior analgesia. It is also important to emphasize the possibility of long-term effects of anesthetics on cognitive function. More research is warranted to develop best practices strategies for the future that are evidence-based.

A randomized trial to identify the most effective dose of remifentanil during Le Fort I osteotomy

PURPOSE

The Le Fort I osteotomy (L-I) requires extensive dissection and manipulation of tissue, causing hemodynamic instability and an undesirable postoperative stress response. This study aimed to clarify the most effective dose of remifentanil during L-I.

MATERIALS AND METHODS

This study was designed as a prospective, randomized, controlled double-blinded study. Patients (American Society of Anesthesiologists physical status I to II) undergoing L-I were randomly assigned to receive anesthesia with propofol and remifentanil under 3 remifentanil dose conditions: 0.25 μg/kg/minute (group 1), 0.5 μg/kg/minute (group 2), and 0.75 μg/kg/minute (group 3). All patients underwent L-I with propofol and remifentanil target-controlled anesthesia. The study endpoints were mean arterial pressure (MAP) and heart rate. Data were recorded before L-I (20-minute period before surgery), during L-I (from the beginning of surgery to downfracture), and after L-I (20-minute period after downfracture). Average age, gender, average body mass index, aimed maxillary position, average bispectral index, average surgery time, and average blood loss also were examined. Data were analyzed using the Bartlett test and then 1-way analysis of variance with the Bonferroni multiple comparison test.

RESULTS

Data were obtained from 20 patients (9 men, 11 women). The average operating times for groups 1, 2, and 3 were 53.1, 46.7, and 49 minutes, respectively. The age range was 18 to 46 years (average, 26.05 yr). The rate of MAP increase from before to during L-I in group 1 was 10.8% (n = 7). The rate of MAP increase from before to during L-I in group 3 was 2.1% (n = 6). Group 3 showed a significantly lower rate of MAP increase during and after L-I compared with group 1 (P < .05).

CONCLUSION

Remifentanil administration at 0.75 μg/kg/minute stabilized hemodynamics during L-I without major side effects. Results indicated that the standard index of remifentanil administration during L-I should be 0.75 μg/kg/minute when using oxygen, propofol, and remifentanil for general anesthesia.

Dexmedetomidine in the supratentorial craniotomy

OBJECTIVE

In this double-blind prospective clinical study, we investigated the effects of fentanyl and dexmedetomidine as adjuvant agents in supratentorial craniotomies on the following: hemodynamic changes during perioperative and recovery periods, brain edema perioperatively, recovery times and side effects, such as hypertension, shivering, nausea and vomiting.

MATERIALS AND METHODS

Thirty consenting ASA physical status I-II patients undergoing intracranial tumor surgery were randomly divided in two groups. In group D (n=15), dexmedetomidine was infused as a 1 μg/kg bolus dose 10 minutes before induction of anesthesia and maintained with 0.4-0.5 μg/kg/min during the operation. In group F (n=15), animals were given fentanyl 0.02 μg/kg/min as an infusion for anesthesia maintenance. At induction, fentanyl was given as a 2 μg/kg dose in group D and as a 4 μg/kg dose in group F. Hemodynamic changes, recovery times and postoperative side effects were recorded before induction, during the perioperative period and 24 hours postoperatively.

RESULTS

In group D; MAP and HR values after intubation, after skull clamp insertion and after extubation were lower than in group F (p<0.05). In group D, cerebral relaxation scores were also significantly lower. Recovery times were found to be shorter in group D as compared to group F; the same trend was observed for the supplemental opioid requirement. During the postoperative period, there was no shivering, nausea or vomiting in group D, but in group F, 3 patients complained of shivering, and 2 patients experienced nausea and vomiting.

CONCLUSION

In our study, we found that dexmedetomidine controlled the hemodynamic changes better than fentanyl perioperatively, after extubation and during the early postoperative period. Our results suggest that that dexmedetomidine is safer and more effective in controlling hemodynamic changes during surgical stimulation than the standard agents used in neuroanesthesia.

[Effect of intraoperative esmolol infusion on anesthetic, analgesic requirements and postoperative nausea-vomitting in a group of laparoscopic cholecystectomy patients]

PURPOSE

Postoperative pain and nausea/vomitting (PNV) are common in laparoscopic cholecystectomy patients. Sympatholytic agents might decrease requirements for intravenous or inhalation anesthetics and opioids. In this study we aimed to analyze effects of esmolol on intraoperative anesthetic-postoperative analgesic requirements, postoperative pain and PNV.

METHODS

Sixty patients have been included. Propofol, remifentanil and vecuronium were used for induction. Study groups were as follows; I - Esmolol infusion was added to maintenance anesthetics (propofol and remifentanil), II - Only propofol and remifentanil was used during maintenance, III - Esmolol infusion was added to maintenance anesthetics (desflurane and remifentanil), IV - Only desflurane and remifentanil was used during maintenance. They have been followed up for 24h for PNV and analgesic requirements. Visual analog scale (VAS) scores for pain was also been evaluated.

RESULTS

VAS scores were significantly lowest in group I (p=0.001-0.028). PNV incidence was significantly lowest in group I (p=0.026). PNV incidence was also lower in group III compared to group IV (p=0.032). Analgesic requirements were significantly lower in group I and was lower in group III compared to group IV (p=0.005). Heart rates were significantly lower in esmolol groups (group I and III) compared to their controls (p=0.001) however blood pressures were similar in all groups (p=0.594). Comparison of esmolol groups with controls revealed that there is a significant decrease in anesthetic and opioid requirements (p=0.024-0.03).

CONCLUSION

Using esmolol during anesthetic maintenance significantly decreases anesthetic-analgesic requirements, postoperative pain and PNV.

Comparative induction of controlled circulation by magnesium and remifentanil in spine surgery

AIM: To evaluate the efficacy of magnesium sulfate (MGS) in comparison with remifentanil for induction of relative hypotension in posterior fusion of spine (PSF).

METHODS: In this randomized clinical trial, 40 patients with the American Society of Anesthesiologists I and II physical status undergoing lumbar PSF were randomized to receive remifentanil (REM) 0.15 μg/kg or MGS 50 mg/kg for controlled hypotension. The administering anesthesiologist was blinded to the medication. Continuous infusion was maintained at a fixed volume rate to deliver precalculated doses of either study drugs. All other aspects of anesthesia and surgery were similar in the two groups. The target mean arterial pressure (MAP) range used in this study was 60-70 mmHg. In the course of surgery, the hemodynamic variables, volume of blood loss, urine output, fluid intake and surgeon’s satisfaction were recorded. Data was analyzed with SPSS version 13.0 and P values less than 0.05 were considered significant.

RESULTS: Twenty patients in the MGS group and 19 patients in the REM group were studied. There was no difference between the two groups in the hemodynamic variables, blood loss, urine output, fluid requirement and surgeon’s satisfaction for exposure. The target MAP was achieved in 75% of Mg and 58% of remifentanil groups. Although a higher number of patients in the REM group required nitroglycerin (42.1%) to reach the target MAP than those in the MGS group (25%), this difference was not statistically significant (P = 0.32).

CONCLUSION: Our findings showed that in patients undergoing lumbar PSF surgery, remifentanil and MGS have a similar hypotensive effect and comparable amount of blood loss without any significant adverse effects.

Effect of remifentanil on the hemodynamic responses and recovery profile of patients undergoing single jaw orthognathic surgery

The aim of this study was to compare fentanyl-based versus remifentanil-based anesthesia with regards to the intraoperative hemodynamic stress response and recovery profiles in patients undergoing Le Fort I osteotomy. Seventeen patients were randomly divided into two groups: patients in the F-group received 2 μg/kg fentanyl intravenously followed by an infusion of 0.03-0.06 μg/kg/min, while patients in the R-group received a 0.5 μg/kg bolus of remifentanil followed by an infusion of 0.0625-0.250 μg/kg/min. Mean arterial pressure and heart rate were recorded at the following points: before anesthetic induction, at endotracheal intubation, 5 min after intubation, at incision, just before the osteotomy, during the osteotomy, during the maxillary fracturing, at suturing, at extubation, 5 min after extubation, and then 15 and 30 min postoperatively. Heart rate and mean arterial pressure were significantly lower in the R-group in comparison to the F-group from t1 to t9 (P<0.05). All measured recovery times were significantly shorter in the R-group (P<0.05). The incidence of postoperative side effects was comparable between groups. Remifentanil-based anesthesia is an appropriate alternative to fentanyl during Le Fort I orthognathic surgery; it promotes hemodynamic stability, blunts the stress response to noxious stimuli, and provides a better recovery profile.

Neurologic complications of anesthesia

Neurologic complications after anesthesia are relatively uncommon but occasionally severe. Intraoperative intracranial hypertension in patients with brain masses, delayed arousal, and postoperative delirium and cognitive dysfunction are among the main complications of general anesthesia. Neuropathy and transient gluteal and leg pain are the most frequent complications of regional blockade. Seizures are infrequent with both anesthesia modalities. Patients with primary neurologic disorders, such as neurodegenerative or neuromuscular conditions, can be at risk for specific complications, and the anesthesia plan must be cautiously adjusted in these patients. In the neurointensive care unit, the complications from large doses of anesthetic agents used for suppression of seizures or control of intracranial pressure are different from those seen perioperatively. Propofol infusion syndrome can be life-threatening when administered for those indications.

Esmolol: a unique Beta-blocker in maintaining cardiovascular stability following neurosurgical procedures

PURPOSE

Patients with increased intracranial pressure (ICP) are prone to severe cardiac and or cerebral complications following emergence from general anesthesia and especially post-extubation phase. Administering beta blockers including esmolol is believed to be helpful in providing a stable hemodynamic at the end of the surgery and recovery stages and reducing recovery phase length.

METHOD

In a double-blind prospective randomized clinical trial, 60 adult patients with ASA (American Society of Anesthesiologist) class of I-II scheduled to undergo elective neurosurgery operations were randomly divided into two groups receiving esmolol (n=30) and placebo (n=30) as IV infusion within four minutes prior to extubation continued by an IV infusion for 10 minutes after extubation.

RESULT

There was a significant difference between two groups regarding the changes of systolic blood pressure and heart rate at all studied stages after extubation (P≤0.05). However, no significant difference existed between esmolol and control groups regarding recovery and extubation times emphasizing the fact that esmolol is of excellent early recovery and extubation profiles.

CONCLUSION

Esmolol is advised to be used in preventing hyperdynamic status throughout extubation phase without extending recovery phase length.

Superior recovery profiles of propofol-based regimen as compared to isoflurane-based regimen in patients undergoing craniotomy for primary brain tumor excision: a retrospective study

PURPOSE

Studies comparing the recovery profiles of isoflurane- and propofol-based anesthesia for major intracranial surgery have reported contradictory results. The aim of our study was to clarify the emergence status in both regimens by investigating uniformly managed neuroanesthesia cases.

METHODS

The anesthesia database at Yamagata University Hospital covering the period 2002-2005 was retrospectively investigated for adult patients who underwent craniotomy for primary brain tumor excision. General anesthesia was provided by an isoflurane- (ISO group) or propofol-based (PROP group) regimen. Times to extubation and operating room (OR) discharge, perioperative consciousness levels, and perioperative variables were compared.

RESULTS

Of the 202 surgeries performed during the study period, 77 and 82 patients were anesthetized with isoflurane and propofol, respectively. Demographic data were comparable between the two groups, although the American Society of Anesthesiology grade was worse in the PROP group. Extubation times [39.5 ± 14.6 min (ISO) vs. 29.5 ± 14.9 min (PROP); P < 0.001] and OR discharge times [67.2 ± 18.0 (ISO) vs. 53.9 ± 17.6 min (PROP); P < 0.001] were significantly shorter in the PROP, with significantly better immediate consciousness levels. The differences in levels of consciousness persisted for several hours postoperatively. PROP patients had significantly higher urine outputs and lower body temperatures during anesthesia. The incidences of shivering, nausea, vomiting, and convulsions were not significantly different between the groups. The time to discharge was similar between the groups.

CONCLUSIONS

Propofol was associated with a better recovery profile and neurological condition than isoflurane, as indicated by shorter extubation and OR discharge times and better postoperative consciousness.

Administration of Remifentanil in Establishing a more Stable Post-anesthesia Cardiovascular Status in Neurosurgical Procedures

INTRODUCTION

Emergence from general anesthesia and especially post-extubation phase are the stages associated with cardiovascular hyperdynamic status in which patients with increased intracranial pressure (ICP) could be affected by severe cardiac and or cerebral complications. Administering remifentanil could be helpful in maintaining the hemodynamic stability at the end of the surgery and recovery stages and reducing recovery phase length.

METHODS

In a double-blind prospective randomized clinical trial, 60 adult patients with ASA (American Society of Anesthesiologist) class of I-II scheduled to undergo elective neurosurgery operations were randomly divided into two groups receiving remifentanil and placebo as IV infusion within four minutes prior to extubation continued by an IV infusion for 10 minutes after extubation.

RESULTS

There was a significant difference between two groups regarding the changes of Mean Arterial Pressure after extubation and five minutes after extubation (P˂ 0.001).Remifentanil group compared with control group was of significant difference at all heart rate values after extubation (P< 0.001).

CONCLUSION

Remifentanil could be used in preventing hyperdynamic status throughout extubation phase without extending recovery phase length. However, administration of this medication should be performed cautiously.

Anesthesia and Intensive care implications for pituitary surgery: Recent trends and advancements

The advancements in neuro-endocrine surgical interventions have been well supported by similar advancements in anesthesiology and intensive care. Surgery of the pituitary tumor poses unique challenges to the anesthesiologists and the intensivists as it involves the principles and practices of both endocrine and neurosurgical management. A multidisciplinary approach involving the endocrine surgeon, neurosurgeon, anesthesiologist, endocrinologist and intensivist is mandatory for a successful surgical outcome. The focus of pre-anesthetic checkup is mainly directed at the endocrinological manifestations of pituitary hypo or hyper-secretion as it secretes a variety of essential hormones, and also any pathological state that can cause imbalance of pituitary secretions. The pathophysiological aspects associated with pituitary tumors mandate a thorough airway, cardiovascular, neurologic and endocrinological assessment. A meticulous preoperative preparation and definite plans for the intra-operative period are the important clinical components of the anesthetic strategy. Various anesthetic modalities and drugs can be useful to provide a smooth intra-operative period by countering any complication and thus providing an uneventful recovery period.

Remifentanil versus fentanyl compared in a target-controlled infusion of propofol anesthesia: quality of anesthesia and recovery profile

PURPOSE

The aim of the present study was to compare the clinical properties of fentanyl versus remifentanil in a target-controlled infusion (TCI) of propofol anesthesia regimen with bispectral index (BIS) monitoring.

METHODS

Forty consenting patients scheduled for elective septorhinoplasty were prospectively studied as one of two groups: fentanyl (group F) or remifentanil (group R). After loading boluses of fentanyl 3 microg kg(-1) or remifentanil 1 microg kg(-1) were administered, the continuous infusion of fentanyl or remifentanil was started at a rate of 0.03 or 0.15 microg kg(-1) min(-1), respectively. Propofol infusion was then commenced with a 3 microg ml(-1) effect site concentration (Ce) by means of a TCI device. The Ce propofol was adjusted to keep BIS at 50 +/- 10.

RESULTS

The general mean value of propofol Ce for group F and group R was 4.0 and 3.5 microg ml(-1), respectively. As to the recovery profile, the eye opening time (mean, 6.7 vs. 4.6 min), extubation time (mean, 7.3 vs. 4.7 min), and orientation time (mean, 7.6 vs. 4.9 min) were found to be significantly longer in group F than in group R.

CONCLUSION

We concluded that in propofol-based TCI anesthesia under BIS supervision for septorhinoplasty operations, remifentanil was better than fentanyl, especially with respect to emergence from total intravenous anesthesia (TIVA). Furthermore, the durations of anesthesia and operation were rather short, which indicates that fentanyl can be safely used.

[Anaesthesia for endocrine tumor removal]

Endocrine tumors could be defined by their ability to produce structural proteins or hormones common to nervous and endocrine cells. They might induce physiological transforms or outcome adverse events which should be well known in order to prevent or treat them early. The goal of this review was to describe these changes, to describe preoperative assessment, and to discuss intraoperative monitoring and drugs choice based on the literature from the last 30 years. As an example, it should be noticed that: (1) preoperative blood pressure control is essential to prepare phaeochromocytoma for surgery. It should be followed during anaesthesia by intensive fluid load, reversible anaesthetic drugs and rational cardiovascular medications use (as for example remifentanil, sevoflurane, calcium channel blockers and esmolol), and after surgery by narrow clinical and biological monitoring; (2) after medullar thyroid cancer, main adverse events include cervical compressive haematoma and recurrent laryngeal nerve injury as for any thyroid surgery; (3) during pituitary surgery, air embolism might be expected, whereas water dysregulation (diabetes insipidus), corticotroph insufficiency, cerebrospinal fluid (CSF) leak might occur postoperatively. In acromegaly, difficult endotracheal intubation is possible whereas severe Cushing's syndrome may be complicated with hypertensive cardiac failure, infections, thrombosis, delayed cicatrisation; (4) somatostatine analogs are a keystone in carcinoid tumors preoperative and anaesthetic management.

Impact of anesthetic agents on cerebrovascular physiology in children

The role of the pediatric neuroanesthetist is to provide comprehensive care to children with neurologic pathologies. The cerebral physiology is influenced by the developmental stage of the child. The understanding of the effects of anesthetic agents on the physiology of cerebral vasculature in the pediatric population has significantly increased in the past decade allowing a more rationale decision making in anesthesia management. Although no single anesthetic technique can be recommended, sound knowledge of the principles of cerebral physiology and anesthetic neuropharmacology will facilitate the care of pediatric neurosurgical patients.

Esmolol blunts postoperative hemodynamic changes after propofol-remifentanil total intravenous fast-track neuroanesthesia for intracranial surgery

STUDY OBJECTIVE

To investigate whether esmolol is effective in attenuating postoperative hemodynamic changes related to sympathetic overdrive.

DESIGN

Clinical study.

SETTING

Operating room of a university hospital.

PATIENTS

60 ASA physical status I, II, and III patients, age 18 to 65 years, scheduled for elective craniotomy for supratentorial neurosurgery.

INTERVENTIONS

Patients were given total intravenous anesthesia (TIVA) during emergence from anesthesia and up to 60 minutes after extubation. Those patients who had hypertension (defined as an increase in systolic blood pressure >20% from baseline values) and tachycardia (defined as an increase >20% in heart rate from baseline) received a loading dose of 500 microg/kg esmolol in one minute, followed by an infusion titrated stepwise (50, 100, 200, and 300 microg/kg per min) every two minutes.

MEASUREMENTS

The mean dose and duration of esmolol therapy were measured.

MAIN RESULTS

Of 60 patients, 49 (82%) who received propofol-remifentanil TIVA developed significant tachycardia and hypertension soon after extubation. Treatment with esmolol (500 microg/kg in bolus maintained at a mean rate of 200 +/- 50 microg/kg per min) effectively controlled hypertension and tachycardia in 45 of 49 patients (92%; P < 0.05) within a mean 4.30 +/- 2.20 minutes. After extubation, mean esmolol infusion time was 29 +/- 8 minutes.

CONCLUSION

In patients undergoing elective neurosurgery with propofol-remifentanil TIVA, a relatively small esmolol dose and short infusion time effectively blunts early postoperative arterial hypertension and tachycardia.

Comparison of Laryngeal Mask with Endotracheal Tube for Anesthesia in Endoscopic Sinus Surgery

Background

The purpose of this study was to compare surgical conditions, including the amount of intraoperative bleeding as well as intraoperative blood pressure, during functional endoscopic sinus surgery (FESS) using flexible reinforced laryngeal mask airway (FRLMA) versus endotracheal tube (ETT) in maintaining controlled hypotension anesthesia induced by propofol-remifentanil total i.v. anesthesia (TIVA).

Methods

Sixty normotensive American Society of Anesthesiologists I—II adult patients undergoing FESS under controlled hypotension anesthesia caused by propofol-remifentanil-TIVA were randomly assigned into two groups: group I, FRLMA; group II, ETT. Hemorrhage was measured and the visibility of the operative field was evaluated according to a six-point scale.

Results

Controlled hypotension was achieved within a shorter period using laryngeal mask using lower rates of remifentanil infusion and lower total dose of remifentanil.

Conclusion

In summary, our results indicate that airway management using FRLMA during controlled hypotension anesthesia provided better surgical conditions in terms of quality of operative field and blood loss and allowed for convenient induced hypotension with low doses of remifentanil during TIVA in patients undergoing FESS.

Planning for early emergence in neurosurgical patients: a randomized prospective trial of low-dose anesthetics

BACKGROUND

For early detection of a cerebral complication, rapid awakening from anesthesia is essential after craniotomy. Systemic hypertension is a major drawback associated with fast tracking, which may predispose to formation of intracranial hematoma. Although various drugs have been widely evaluated, there are limited data with regards to use of anesthetics to blunt emergence hypertension. We hypothesized that use of low-dose anesthetics during craniotomy closure facilitates early emergence with a decrease in hemodynamic consequences.

METHODS

Three emergent techniques were evaluated in 150 normotensive adult patients operated for supratentorial tumors under standard isoflurane anesthesia. At the time of dural closure, the patients were randomized to receive low-dose propofol (3 mg.kg(-1).h(-1)), fentanyl (1.5 microg.kg(-1).h(-1)) or isoflurane (end-tidal concentration of 0.2%) until the beginning of skin closure. Nitrous oxide was discontinued after head dressing.

RESULTS

Median time to emergence was 6 min with propofol, 4 min with fentanyl, and 5 min with isoflurane (P=0.008). More patients had hypertension in the pre-extubation compared with extubation or postextubation phase (P=0.009). Comparing the three groups, fewer patients required esmolol with fentanyl use overall, and in the pre-extubation phase (P=0.01). Significant midline shift in the preoperative cerebral imaging scans was found to be an independent risk factor for emergence hypertension.

CONCLUSIONS

Pain during surgical closure may be an important cause of sympathetic stimulation leading to emergence hypertension. The use of low-doses of fentanyl during craniotomy closure is more advantageous than propofol or isoflurane for early emergence in neurosurgical patients and is the most effective technique for preventing early postoperative hypertension.

The perioperative management of pain from intracranial surgery

Analgesic therapy following intracranial procedures remains a source of concern and controversy. Although opioids are the mainstay of the "balanced" general anesthetic techniques frequently used during intracranial procedures, neurosurgeons and others have been reluctant to administer opioid analgesics to patients following such procedures. This practice is supported by the concern that the sedation and miosis associated with opioid administration could mask the early signs of intracranial catastrophe, or even exacerbate it through decreased ventilatory drive, elevated arterial carbon dioxide levels, and increased cerebral blood flow. This reluctance to use opioids following intracranial surgery is enabled by decades of training and anecdote emphasizing that pain is minimal following these procedures. However, recent data suggests otherwise, and raises the question of how to provide safe and effective analgesia for these patients. Here, this data is reviewed along with the relevant pain pathways, analgesic drugs and techniques, and the available data on their use following intracranial surgery. Although pain following intracranial surgery appears to be more intense than initially believed, it is readily treated safely and effectively with techniques that have proven useful following other types of surgery, including patient-controlled administration of opioids. The use of multimodal analgesic therapy is emphasized not only for its effectiveness, but to reduce dosages and, therefore, side effects, primarily of the opioids, that could be of legitimate concern to physicians and affect the comfort of their patients.

Remifentanil for general anaesthesia: a systematic review

We performed a quantitative systematic review of randomised, controlled trials that compared remifentanil to short-acting opioids (fentanyl, alfentanil, or sufentanil) for general anaesthesia. Eighty-five trials were identified and these included a total of 13 057 patients. Intra-operatively, remifentanil was associated with clinical signs of deeper analgesia and anaesthesia, such as fewer responses to noxious stimuli (relative risk 0.65, 95% CI 0.48-0.87), more frequent episodes of bradycardia (1.46, 1.04-2.05), more hypotension (1.68, 1.36-2.07) and less hypertension (0.60, 0.46-0.78). Postoperatively, remifentanil was associated with faster recovery (difference in extubation time of -2.03, 9.5% CI, -2.92 to -1.14 min), more frequent postoperative analgesic requirements (1.36, 1.21-1.53) and fewer respiratory events requiring naloxone (0.25, 0.14-0.47). Remifentanil had no overall impact on postoperative nausea (1.03, 0.97-1.09) or vomiting (1.06, 0.96-1.17), but was associated with twice as much shivering (2.15, 1.73-2.69). Remifentanil does not seem to offer any advantage for lengthy, major interventions, but may be useful for selected patients, e.g. when postoperative respiratory depression is a concern.

The long-term effect of craniotomy on temporalis muscle function

OBJECTIVE

The objective of this study was to evaluate jaw movements and the masticatory muscle in patients who underwent craniotomy for treatment of cerebral aneurysm.

STUDY DESIGN

Descriptive study.

RESULTS

There were 71 patients evaluated between 4 and 6 months after craniotomy, by means of a systematized approach. Their mean age was 45.3 years. Thirty-four (47.9%) patients complained of headache during dental evaluation. Twenty (28.2%) patients reported pain during normal jaw movements. There was a correlation between pain complaints and jaw movements during dental examinations (P = .03). Patients with postcraniotomy headache had more masticatory muscle tenderness on palpation than those without post-craniotomy headache (P < .02). Jaw protrusion was worse than the reference values (P < .01).

CONCLUSIONS

Headache was the complaint in 47.9% of the sample. Jaw movement was statistically a pain-precipitating factor. Patients who suffered from postcraniotomy headache had more masticatory muscle tenderness. There were functional jaw limitations.

Anaesthesia for elective neurosurgery

Neuroanaesthesia continues to develop and expand. It is a speciality where the knowledge and expertise of the anaesthetist can directly influence patient outcome. Evolution of neurosurgical practice is accompanied by new challenges for the anaesthetist. Increasingly, we must think not only as an anaesthetist but also as a neurosurgeon and neurologist. With the focus on functional and minimally invasive procedures, there is an increased emphasis on the provision of optimal operative conditions, preservation of neurocognitive function, minimizing interference with electrophysiological monitoring, and a rapid, high-quality recovery. Small craniotomies, intraoperative imaging, stereotactic interventions, and endoscopic procedures increase surgical precision and minimize trauma to normal tissues. The result should be quicker recovery, minimal perioperative morbidity, and reduced hospital stay. One of the peculiarities of neuroanaesthesia has always been that as much importance is attached to wakening the patient as sending them to sleep. With the increasing popularity of awake craniotomies, there is even more emphasis on this skill. However, despite high-quality anaesthetic research and advances in drugs and monitoring modalities, many controversies remain regarding best clinical practice. This review will discuss some of the current controversies in elective neurosurgical practice, future perspectives, and the place of awake craniotomies in the armamentarium of the neuroanaesthetist.

Awakening management after neurosurgery for intracranial tumours

PURPOSE OF REVIEW

Major complications after intracranial surgery occur in 13-27% of patients. These complications may have multiple causes, but a body of arguments suggests that the haemodynamic and metabolic changes of anaesthesia recovery may be responsible for intracranial complications. The aim of this review is to explain the rationale of this hypothesis and analyse the recent studies relevant to neuroanaesthesia recovery.

RECENT FINDINGS

Rapid recovery and extubation after intracranial tumour surgery is desirable in order to make an early diagnosis of intracranial complications. Since light pharmacological sedation may worsen a neurological deficit, short-acting anaesthetics are preferable intraoperatively. Extubation in the operating room, however, may be associated with agitation, increased oxygen consumption, catecholamine secretion, hypercapnia and systemic hypertension. This may exacerbate cerebral hyperaemia observed even during an uneventful recovery, leading to cerebral oedema or haemorrhage.

SUMMARY

Pain, hypothermia, hypercapnia, hypoxia, hypoosmolality, hypertension, and anaemia should be avoided during emergence. Early emergence is associated with minimal haemodynamic and metabolic changes. If there is any doubt as to whether the patient should be extubated in the operating room, a gradual emergence in the intensive care unit makes it possible to decide whether or not extubation can be performed safely.

Dexmedetomidine as an anaesthetic adjuvant in patients undergoing intracranial tumour surgery: a double-blind, randomized and placebo-controlled study †

BACKGROUND

Dexmedetomidine (DEX) has been shown to provide good perioperative haemodynamic stability with decreased intraoperative opioid requirements. It may have neural protective effects, and thus may be a suitable anaesthetic adjuvant to neurosurgical anaesthesia.

METHODS

Fifty-four patients scheduled for elective surgery of supratentorial brain tumour were randomized to receive in a double-blind manner a continuous DEX infusion (plasma target concentration 0.2 or 0.4 ng ml(-1)) or placebo, beginning 20 min before anaesthesia and continuing until the start of skin closure. The DEX groups received fentanyl 2 microg kg(-1) at the induction of anaesthesia and before the start of operation, the placebo group 4 microg kg(-1), respectively. Anaesthesia was maintained with nitrous oxide in oxygen and isoflurane.

RESULTS

The median times from the termination of N2O to extubation were 6 (3-27), 3 (0-20) and 4 (0-13) min in placebo, DEX-0.2 and DEX-0.4 groups, respectively (P<0.05 anova all-over effect). The median percentage of time points when systolic blood pressure was within more or less than 20% of the intraoperative mean was 72, 77 and 85, respectively (P<0.01), DEX-0.4 group differed significantly from the other groups. DEX blunted the tachycardic response to intubation (P<0.01) and the hypertensive response to extubation (P<0.01). DEX-0.4 group differed in the heart rate variability from placebo (93 vs 82%, P<0.01).

CONCLUSIONS

DEX increased perioperative haemodynamic stability in patients undergoing brain tumour surgery. Compared with fentanyl, the trachea was extubated [corrected] faster without respiratory depression.

A Comparison Between Scalp Nerve Block and Morphine for Transitional Analgesia After Remifentanil-Based Anesthesia in Neurosurgery

We compared transitional analgesia provided by scalp nerve block (SNB) or morphine after remifentanil-based anesthesia in neurosurgery. Fifty craniotomy patients were randomly divided into two groups: morphine (morphine 0.1 mg x kg(-1) IV after dural closure and an SNB performed with 20 mL of 0.9% saline at the end of surgery) and block (10 mL of 0.9% saline instead of morphine after dural closure and an SNB performed with a 1:1 mixture of bupivacaine 0.5% and lidocaine 2% at the end of surgery). Postoperative pain was assessed at 1, 2, 4, 8, 12, 16, and 24 h using a 10-point numerical rating scale. Analgesia consisted of subcutaneous codeine. Average numerical rating scale scores were similar between the two groups at each time interval. Total codeine dosage was also similar, except at 4 h postoperatively when it was higher in the block group. The delay before administration of the first dose of codeine was not statistically different between groups: 45 min (20-2880) vs 30 min (10-2880), median and range for the block and morphine group, respectively. Postoperative hemodynamics were similar for both groups. The incidence of nausea and vomiting was slightly more frequent in the morphine group, but the occurrence of confusion did not differ between groups. In conclusion, SNB provides a quality of transitional analgesia that is similar to that of morphine with the same postoperative hemodynamic profile.