A review of scalp blockade for cranial surgery

Regional Anesthesia Techniques in Modern Neuroanesthesia Practice: A Narrative Review of the Clinical Evidence

Neurosurgical procedures are often associated with significant postoperative pain that is both underrecognized and undertreated. Given the potentially undesirable side effects associated with general anesthesia and with various pharmacological analgesic regimens, regional anesthetic techniques have gained in popularity as alternatives for providing both anesthesia and analgesia for the neurosurgical patient. The aim of this narrative review is to present an overview of the regional techniques that have been incorporated and continue to be incorporated into modern neuroanesthesia practice, presenting in a comprehensive way the evidence, where available, in support of such practice for the neurosurgical patient.

Dexmedetomidine Prevents Chronic Incisional Pain After Brain Tumor Resection: A Secondary Analysis of the Randomized Control Trial

BACKGROUND

Dexmedetomidine was reported to reduce postoperative acute pain after neurosurgery. However, the efficacy of dexmedetomidine for preventing chronic incisional pain is uncertain.

METHODS

This article is a secondary analysis of a randomized, double-blind, placebo-controlled trial. Eligible patients were randomly allocated to either the dexmedetomidine group or the placebo group. Patients assigned to the dexmedetomidine group were given a 0.6 μg kg -1 dexmedetomidine bolus followed by a 0.4 μg kg -1 h -1 maintenance dose until dural closure; placebo patients were given comparable amounts of normal saline. The primary end point was the incidence of incisional pain at 3 months after craniotomy evaluated by numerical rating scale scores and defined as any score >0. The secondary end points were postoperative acute pain scores, sleep quality, and Short-Form McGill Pain Questionnaire (SF-MPQ-2) at 3 months after craniotomy.

RESULTS

From January 2021 to December 2021, a total of 252 patients were included in the final analysis: the dexmedetomidine group (n = 128) and the placebo group (n = 124). The incidence of chronic incisional pain was 23.4% (30 of 128) in the dexmedetomidine group versus 42.7% (53 of 124) in the placebo group (risk ratio, 0.55; 95% confidence interval, 0.38-0.80; P = .001). The overall severity of chronic incisional pain was mild in both groups. Patients in the dexmedetomidine group had lower acute pain severity on movement than those in the placebo group for the first 3 days after surgery (all adjusted P < .01). Sleep quality did not differ between groups. However, the SF-MPQ-2 total sensory ( P = .01) and neuropathic pain descriptor ( P = .023) scores in the dexmedetomidine group were lower than those in the placebo group.

CONCLUSIONS

Prophylactic intraoperative dexmedetomidine infusion reduces the incidence of chronic incisional pain as well as acute pain score after elective brain tumor resections.

Association of scalp block with intraoperative hemodynamic profiles and postoperative pain outcomes at 24-48 hours following craniotomy: An updated systematic review and meta-analysis of randomized controlled studies

BACKGROUND

Despite the demonstrated analgesic efficacy of scalp block (SB) during the immediate postoperative period, the impact of SB on pain outcomes at postoperative 24 and 48 h in adults receiving craniotomy remains unclear.

METHODS

The databases of Medline, Embase, and Cochrane Central Register were searched from inception to January 2022 for available randomized controlled trials (RCTs). The primary outcome was the severity of pain at postoperative 24 and 48 h, while the secondary outcomes included morphine consumption, hemodynamic profiles after surgical incision and in the postanesthesia care unit (PACU), and risk of postoperative nausea/vomiting (PONV).

RESULTS

Meta-analysis of 12 studies revealed a lower pain score [MD = -0.83, p = 0.03, 375 patients, certainty of evidence (COE): low] and morphine consumption (MD = -9.21 mg, p = 0.03, 246 patients, COE: low) at postoperative 24 h, while there were no differences in these pain outcomes at postoperative 48 h (COE: low). The use of SB significantly decreased intraoperative heart rate (MD = -10.9 beats/min, p < 0.0001, 189 patients, COE: moderate) and mean blood pressure (MD = -13.02 mmHg, p < 0.00001, 189 patients, COE: moderate) after surgical incision, but these hemodynamic profiles were comparable in both groups in the PACU setting. There was also no difference in the risk of PONV between the two groups (RR = 0.78, p = 0.2, 299 patients, COE: high).

CONCLUSION

This meta-analysis demonstrated that scalp block not only provided hemodynamic stability immediately after surgical incision but was also associated with a lower pain score and morphine consumption at postoperative 24 h. Further studies are needed for elucidation of its findings.

Effect of Scalp Nerve Block Combined with Intercostal Nerve Block on the Quality of Recovery in Patients with Parkinson’s Disease after Deep Brain Stimulation: Protocol for a Randomized Controlled Trial

Background: Parkinson’s disease (PD) patients who receive deep brain stimulation (DBS) have a higher risk of postoperative pain, which will affect their postoperative quality of recovery (QoR). Scalp nerve block (SNB) and intercostal nerve block (ICNB) can alleviate postoperative pain, yet their effect on postoperative QoR in PD patients has proven to be unclear. Therefore, we have aimed to explore the effect of SNB paired with ICNB on postoperative QoR. Methods: To explore the effect, we have designed a randomized controlled trial in which 88 patients with PD will be randomly assigned to either an SNB group or control group, receiving either SNB combined with ICNB or without before surgery. The primary outcome will be a 15-item QoR score at 24 h after surgery. The secondary outcomes will include: 15-item QoR scores at 72 h and 1 month after surgery; the numeric rating scale pain scores before discharge from the postanesthesia care unit (PACU) at 24 h, 72 h, and 1 month after surgery; rescue analgesics; nausea and vomiting 24 h after operation and remifentanil consumption during operation; emergence agitation; the duration of anesthesia and surgery; time to respiratory recovery, time to response, and time to extubation; the PACU length of stay; as well as adverse events. Proposed protocol and conclusion: Our findings will provide a novel method for the management of recovery and acute pain after DBS in PD patients. This research was registered at clinicaltrials.gov NCT05353764 on 19 April 2022.

Influence of Levobupivacaine Regional Scalp Block on Hemodynamic Stability, Intra- and Postoperative Opioid Consumption in Supratentorial Craniotomies: A Randomized Controlled Trial

BACKGROUND

The anesthetic management of supratentorial craniotomy (CR) necessitates tight intraoperative hemodynamic control. This type of surgery may also be associated with substantial postoperative pain. We aimed at evaluating the influence of regional scalp block (SB) on hemodynamic stability during the noxious events of supratentorial craniotomies and total intravenous anesthesia, its influence on intraoperative anesthetic agents' consumption, and its effect on postoperative pain control.

METHODS

Sixty patients scheduled for elective CR were prospectively enrolled. Patient, anesthesiologist, and neurosurgeon were blind to the random performance of SB with either levobupivacaine 0.33% (intervention group [group SB], n = 30) or the same volume of saline (control group [group CO], placebo group, n = 30). General anesthesia was induced and maintained using target-controlled infusions of remifentanil and propofol that were adjusted according to hemodynamic parameters and state entropy of the electroencephalogram (SE), respectively. Mean arterial blood pressure (MAP), heart rate (HR), SE, and propofol and remifentanil effect-site concentrations (Ce) were recorded at the time of scalp block performance (Baseline), and 0, 1, 3, and 5 minutes after skull-pin fixation (SP), skin incision (SI), CR, and dura-mater incision (DM). Morphine consumption and postoperative pain intensity (0-10 visual analog scale [VAS]) were recorded 1, 3, 6, 24, and 48 hours after surgery. Propofol and remifentanil overall infusion rates were also recorded. Data were analyzed using 2-tailed Student unpaired t tests, 2-way mixed-design analysis of variance (ANOVA), and Tukey's honestly significant difference (HSD) tests for post hoc comparisons as appropriate.

RESULTS

Demographics and length of anesthetic procedure of group CO and SB were comparable. SP, SI, and CR were associated with a significantly higher MAP in group CO than in group SB, at least at one of the time points of recording surrounding those noxious events. This was not the case at DM. Similarly, HR was significantly higher in group CO than in group SB during SP and SI, at least at 1 of the points of recording, but not during CR and DM. Propofol and remifentanil Ce and overall infusion rates were significantly higher in group CO than in group SB, except for propofol Ce during SP. Postoperative pain VAS and cumulative morphine consumption were significantly higher in group CO than in group SB.

CONCLUSIONS

In supratentorial craniotomies, SB improves hemodynamic control during noxious events and provides adequate and prolonged postoperative pain control as compared to placebo.

Regional Anesthesia in Neuroanesthesia Practice

Regional anesthesia has been an undervalued entity in neuroanesthetic practice. However, in the past few years, owing to the development of more advanced techniques, drugs and the prolific use of ultrasound guidance, the unrecognised potential of these modalities have been highlighted. These techniques confer the advantages of reduced requirements for local anesthetics, improved hemodynamic stability in the intraoperative period, better pain score postoperatively and reduced analgesic requirements in the postoperative period. Reduced analgesic requirement translates into lesser side effects associated with analgesic use. Furthermore, the transition from the traditional blind landmark-based techniques to the ultrasound guidance has increased the reliability and the safety profile. In this review, we highlight the commonly practised blocks in the neuroanesthesiologist's armamentarium and describe their characteristics, along with their individual particularities.

Effect of Scalp Nerve Block with Ropivacaine on Postoperative Pain in Patients Undergoing Craniotomy: A Randomized, Double Blinded Study

Scalp nerve block with ropivacaine has been shown to provide perioperative analgesia. However, the best concentration of ropivacaine is still unknown for optimal analgesic effects. We performed a prospective study to evaluate the effects of scalp nerve block with varied concentration of ropivacaine on postoperative pain and intraoperative hemodynamic variables in patients undergoing craniotomy under general anesthesia. Eighty-five patients were randomly assigned to receive scalp block with either 0.2% ropivacaine, 0.33% ropivacaine, 0.5% ropivacaine, or normal saline. Intraoperative hemodynamics and post-operative pain scores at 2, 4, 6, 24 hours postoperatively were recorded. We found that scalp blockage with 0.2% and 0.33% ropivacaine provided adequate postoperative pain relief up to 2 h, while administration of 0.5% ropivacaine had a longer duration of action (up to 4 hour after craniotomy). Scalp nerve block with varied concentration of ropivacaine blunted the increase of mean arterial pressure in response to noxious stimuli during incision, drilling, and sawing skull bone. 0.2% and 0.5% ropivacaine decreased heart rate response to incision and drilling. We concluded that scalp block using 0.5% ropivacaine obtain preferable postoperative analgesia compared to lower concentrations. And scalp block with ropivacaine also reduced hemodynamic fluctuations in craniotomy operations.

REGIONAL ANESTHESIA FOR NEUROSURGERY

During neurosurgery procedures it is vital to assure optimal cerebral perfusion and oxygenation. Despite physiological autoregulation of brain perfusion, maintaining hemodynamic stability and good oxygenation during anesthesia is vital for success. General anesthesia with mechanical ventilation and current drugs provide excellent hemodynamic condition and it is the first choice for most neurosurgery procedures. However, sometimes it is very hard to avoid brief increase or decrease in blood pressure especially during period of intense pain, or without pain stimulation. This could be detrimental for patients presented with high intracranial pressure and brain edema. Modifying anesthesia depth or treatment with vasoactive drugs usually is needed to overcome such circumstances. On the other hand it is important to wake the patients quickly after anesthesia for neurological exam. That is why regional anesthesia of scalp and spine could show beneficial effects by decreasing pain stimuli and hemodynamic variability with sparing effect of anesthetics drugs. Also regional techniques provide excellent postoperative pain relief, especially after spinal surgery

Pain management in neurocritical care; an update

PURPOSE OF REVIEW

Pain management in neurocritical care is a subject often avoided because of concerns over the side-effects of analgesics and the potential to cause additional neurological injury with treatment. The sedation and hypercapnia caused by opioids have been feared to mask the neurological examination and contribute to elevations in intracranial pressure. Nevertheless, increasing attention to patient satisfaction has sparked a resurgence in pain management. As opioids have remained at the core of analgesic therapy, the increasing attention to pain has contributed to a growing epidemic of opioid dependence. In this review, we summarize the most recent literature regarding opioids and their alternatives in the treatment of acute pain in patients receiving neurocritical care.

RECENT FINDINGS

Studies on pain management in neurocritical care continue to explore nonopioid analgesics as part of a multimodal strategy aimed at decreasing overall opioid consumption. Agents including local anesthetics, acetaminophen, ketamine, gabapentinoids, and dexmedetomidine continue to demonstrate efficacy. In addition, the prolonged longitudinal course of many recent trials has also revealed more about the transition from acute to chronic pain following hospitalization.

SUMMARY

In an era of increasing attention to patient satisfaction mitigated by growing concerns over the harms imposed by opioids, alternative analgesic therapies are being investigated with promising results.

Description of a regional anaesthesia technique for the dorsal cranium in the dog: a cadaveric study

OBJECTIVE

To identify landmarks and to describe a technique for nerve blockade of the dorsal cranium in dogs.

STUDY DESIGN

Anatomic cadaveric study.

ANIMALS

A total of 39 dog cadavers, weighing 18.0 ± 9.7 kg (mean ± standard deviation).

METHODS

The study was performed in three parts. In the initial part, cadavers were dissected to determine the location of the frontal, zygomaticotemporal, and major occipital nerves, and to identify prominent landmarks for their blockade. In the second part, one technique was developed to block each of the frontal and zygomaticotemporal nerves, and two techniques, rostral and caudal, were developed to block the major occipital nerve. Injection solution was 0.05% methylene blue in 0.5% bupivacaine. In the third part, cadavers were used to test the techniques developed in the second part with 0.04 mL kg^-1 of the same injectate administered at each site (maximal volume 0.5 mL per site). The length of nerve stained was measured, with a length ≥6 mm considered successful. Confidence intervals were calculated using Fisher's exact test.

RESULTS

Success rates (95% confidence interval) for the frontal, zygomaticotemporal, and rostral and caudal locations for the major occipital nerve were 94% (80-99%), 91% (76-98%), 74% (58-86%) and 77% (59-89%), respectively. With a combination of both locations, the success rate for the major occipital nerve was 100% (90-100%).

CONCLUSION AND CLINICAL RELEVANCE

This study describes a simple regional anaesthesia technique using palpable anatomical landmarks that may provide analgesia for dogs undergoing craniotomy.

Local anesthetics for brain tumor resection: current perspectives

This review summarizes the added value of local anesthetics in patients undergoing craniotomy for brain tumor resection, which is a procedure that is carried out frequently in neurosurgical practice. The procedure can be carried out under general anesthesia, sedation with local anesthesia or under local anesthesia only. Literature shows a large variation in the postoperative pain intensity ranging from no postoperative analgesia requirement in two-thirds of the patients up to a rate of 96% of the patients suffering from severe postoperative pain. The only identified causative factor predicting higher postoperative pain scores is infratentorial surgery. Postoperative analgesia can be achieved with multimodal pain management where local anesthesia is associated with lower postoperative pain intensity, reduction in opioid requirement and prevention of development of chronic pain. In awake craniotomy patients, sufficient local anesthesia is a cornerstone of the procedure. An awake craniotomy and brain tumor resection can be carried out completely under local anesthesia only. However, the use of sedative drugs is common to improve patient comfort during craniotomy and closure. Local anesthesia for craniotomy can be performed by directly blocking the six different nerves that provide the sensory innervation of the scalp, or by local infiltration of the surgical site and the placement of the pins of the Mayfield clamp. Direct nerve block has potential complications and pitfalls and is technically more challenging, but mostly requires lower total doses of the local anesthetics than the doses required in surgical-site infiltration. Due to a lack of comparative studies, there is no evidence showing superiority of one technique versus the other. Besides the use of other local anesthetics for analgesia, intravenous lidocaine administration has proven to be a safe and effective method in the prevention of coughing during emergence from general anesthesia and extubation, which is especially appreciated after brain tumor resection.

Designing a pain management protocol for craniotomy: A narrative review and consideration of promising practices

BACKGROUND

Craniotomy is a relatively common surgical procedure with a high incidence of postoperative pain. Development of standardized pain management and enhanced recovery after surgery (ERAS) protocols are necessary and crucial to optimize outcomes and patient satisfaction and reduce health care costs.

METHODS

This work is based upon a literature search of published manuscripts (between 1996 and 2017) from Pubmed, Cochrane Central Register, and Google Scholar. It seeks to both synthesize and review our current scientific understanding of postcraniotomy pain and its part in neurosurgical ERAS protocols.

RESULTS

Strategies to ameliorate craniotomy pain demand interventions during all phases of patient care: preoperative, intraoperative, and postoperative interventions. Pain management should begin in the perioperative period with risk assessment, patient education, and premedication. In the intraoperative period, modifications in anesthesia technique, choice of opioids, acetaminophen and nonsteroidal anti-inflammatory drugs (NSAIDs), regional techniques, dexmedetomidine, ketamine, lidocaine, corticosteroids, and interdisciplinary communication are all strategies to consider and possibly deploy. Opioids remain the mainstay for pain relief, but patient-controlled analgesia, NSAIDs, standardization of pain management, bio/behavioral interventions, modification of head dressings as well as patient-centric management are useful opportunities that potentially improve patient care.

CONCLUSIONS

Future research on mechanisms, predictors, treatments, and pain management pathways will help define the combinations of interventions that optimize pain outcomes.

Effect of Local Ropivacaine on Hemodynamic Responses in Craniotomy Patients

BACKGROUND

Increased intracranial pressure (ICP) with hemodynamic is of major concern to anesthesiologists and surgeons in craniotomy surgery. Thus, the management of hemodynamic stability is essential in neuro-anesthesia. This study was performed to investigate the effect of local infiltration of 0.5% ropivacaine on hemodynamic responses in craniotomy patients.

MATERIAL AND METHODS

64 ASA class I -II patients, scheduled for elective craniotomies, were enrolled in this prospective randomized double blind placebo controlled study. These patients were randomly divided into the ropivacaine group, who were administered with 0.5% ropivacaine (n = 32), and the placebo group administered with 0.9% normal saline (NaCl) (n = 32). Anesthesia was induced with 3 µg/kg fentanyl, 5 mg/kg thiopental and 0.5 mg/kg atracurium, and was maintained with isoflurane (0.8-1 = MAC) in 50% N₂O, 1 mg/kg /30 minutes, 40% oxygen and 0.05 mg/kg /hour fentanyl. Five minutes prior to surgery, 10 mL of 0.5% ropivacaine was injected in the line of skin incision in the ropivacaine group, while 10 mL of normal saline was injected in placebo group. Thereafter, the systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial blood pressures (MABP), and heart rate (HR) were measured before infiltration into the incision area, 30 seconds, 3 minutes, 5, 10, and 30 minutes after infiltration into the scalp. For higher BP and HR, an adjunct 0.5 mcg/kg of fentanyl was prescribed and administered.

RESULTS

A significant difference was observed for SBP, DBP, MABP and HR, between the two groups at different times during craniotomy (p < 0.05). A significant decrease was observed for SBP, DBP, MABP and HR during craniotomy in 0.5% ropivacaine group as compared with placebo group (p < 0.05).

CONCLUSION

Local anesthetic of 0.05% ropivacaine scalp infiltration is effective in clinical usage of regional anesthesia for producing good quality anesthesia, it seems to be a significant choice for management of optimal hemodynamic profile, providing a better hemodynamic stability during craniotomy.

Perioperative Factors Contributing the Post-Craniotomy Pain: A Synthesis of Concepts

The perioperative management of post-craniotomy pain is controversial. Although the concept of pain control in non-neurosurgical fields has grown substantially, the understanding of neurosurgical pain and its causative factors in such a population is inconclusive. In fact, the organ that is the center of pain and its related mechanisms receives little attention to alleviate distress during neurosurgical procedures. In contrast to the old belief that pain following intracranial surgery is minimal, recent data suggest the exact opposite. Despite the evolution of various multimodal analgesic techniques for optimal pain control, the concern of post-craniotomy pain remains. This paradox could be due to the lack of thorough understanding of different perioperative factors that can influence the incidence and intensity of pain in post-craniotomy population. Therefore, this review aims to give an in-depth insight into the various aspects of pain and its related factors in adult neurosurgical patients.

How I do it: Awake craniotomy

BACKGROUND

Awake craniotomy allows continuous assessment of a patient's clinical and neurological status during open brain surgery. This facilitates early detection of interference with eloquent cortex, and hence can allow a surgeon to maximize resection margins without compromising neurological function.

METHODS

Awake craniotomy requires an effective scalp blockade, intraoperative assessment, and a carefully co-ordinated theatre team. A variety of clinical and electrophysiological techniques can be used to assess cortical function.

CONCLUSIONS

Effective scalp blockade and awake craniotomy provides the opportunity to intraoperatively assess cortical function in the awake patient, thus providing an important neurosurgical option for lesions near eloquent cortex.

Efficacy and Safety of a Lidocaine and Ropivacaine Mixture for Scalp Nerve Block and Local Infiltration Anesthesia in Patients Undergoing Awake Craniotomy

BACKGROUND

Mixtures of various local anesthetics, such as lidocaine and ropivacaine, have been widely used. However, their efficacy and safety for scalp nerve blocks and local infiltration during awake craniotomy have not been fully elucidated.

METHODS

We prospectively investigated 53 patients who underwent awake craniotomy. Scalp block was performed for the blockade of the supraorbital, supratrochlear, zygomaticotemporal, auriculotemporal, greater occipital, and lesser occipital nerves with a mixture containing equal volumes of 2% lidocaine and 0.75% ropivacaine, including 5 μg/mL of epinephrine. Infiltration anesthesia was applied at the site of skin incision using the same mixture. The study outcomes included changes in heart rate and blood pressure after head pinning and skin incision, and incidence of severe pain on emergence from anesthesia. Total doses and plasma concentrations of lidocaine and ropivacaine were measured at different time points after performing the block.

RESULTS

The heart rate and blood pressure after head pinning were marginally, but significantly, increased when compared with baseline values. There were no significant differences in heart rate and blood pressure before and after the skin incision. Nineteen percent of the patients (10/53) complained of incisional pain at emergence from anesthesia. The highest observed blood concentrations of lidocaine and ropivacaine were 1.9±0.9 and 1.1±0.4 μg/mL, respectively. No acute anesthetic toxicity symptom was observed.

CONCLUSIONS

Scalp block with a mixture of lidocaine and ropivacaine seems to provide effective and safe anesthetic management in patients undergoing awake craniotomy.

Awake craniotomy for brain tumor: indications, technique and benefits

Increasing interest in the quality of life of patients after treatment of brain tumors has led to the exploration of methods that can improve intraoperative assessment of neurological status to avoid neurological deficits. The only method that can provide assessment of all eloquent areas of cerebral cortex and white matter is brain mapping during awake craniotomy. This method helps ensure that the quality of life and the neuro-oncological result of treatment are not compromised. Apart from the medical aspects of awake surgery, its economic issues are also favorable. Here, we review the main aspects of awake brain tumor surgery. Neurosurgical, neuropsychological, neurophysiological and anesthetic issues are briefly discussed.