Scalp block for analgesia after craniotomy: A meta-analysis

Cost-effectiveness and efficacy of scalp block for elective supratentorial craniotomy in resource-limited settings: A randomized controlled trial

Background

Remifentanil is favored for neurosurgical pain management, but its utilization in low- and middle-income countries (LMICs) is limited. Scalp block techniques are effective in LMICs, but cost-effectiveness is uncertain. This study compares costs and perioperative outcomes of scalp block versus fentanyl infusion in patients undergoing elective supratentorial craniotomy.

Methods

A prospective double-blind randomized controlled trial was conducted with 36 patients aged 18- 65 years undergoing elective supratentorial craniotomy. Patients were randomly assigned to receive either scalp block with 0.5% bupivacaine (Group S) or fentanyl infusion (Group F), with normal saline placebo administered in both groups. The primary endpoint was the anesthetic costs, with secondary endpoints including perioperative opioid consumption, intraoperative hemodynamic changes, and perioperative complications.

Results

The cost of fentanyl was significantly lower than that of local anesthetics (3.31 [3.31, 3.75] vs. 4.27 [4.27, 4.27] United States dollars, P < 0.001). However, the overall anesthetic cost did not differ significantly between groups. Group F demonstrated a significant reduction in mean arterial pressure immediately and 5 min after pin insertion compared to Group S (75.8 [13.9] vs. 92.5 [16.9] mmHg, P = 0.003 and 67.7 [6.4] vs. 78.5 [10.7] mmHg, P < 0.001, respectively).

Conclusion

Fentanyl infusion presents cost advantages over scalp block in LMIC settings. However, prudent opioid use is imperative. This study underscores the need for ongoing research to optimize neurosurgical pain management and evaluate long-term safety implications.

Scalp Nerve Block for Enhanced Pain Control and Analgesic Optimization in Elective Craniotomy: A Randomized Controlled Trial with Analgesia Nociception Index Monitoring

BACKGROUND

In patients who are candidates for craniotomy, scalp nerve blocks have been shown to be effective in relieving pain intensity as well as postoperative hemodynamic stability after surgery, but the results have been inconsistent. We aimed to assess the effect of scalp block on pain control, intraoperative drug use under Analgesia Nociception Index (ANI) monitoring, and postoperative pain in patients who were candidates for elective craniotomy.

METHODS

In this randomized, single-blinded clinical trial study, candidates for craniotomy were randomly (using the block randomization method) divided into 2 groups before entering the operating room. The first group received a scalp block with bupivacaine (intervention), and the second group did not receive a scalp block (control) besides the routine anesthetic procedure in these patients. ANI, hemodynamic parameters, and the amounts of received remifentanil were conducted and compared.

RESULTS

Patients under scalp block received less dosage of fentanyl than the nonscalp block group (mean = 57.14 ± 15.59 mcg vs. 250.00 ± 65.04 mcg, respectively). Similarly, the dose of remifentanil required in the scalp block group was less (mean = 3.04 ± 1.95 mg and 5.54 ± 2.57 mg, respectively). No difference was observed in hemodynamic parameters such as blood pressure and heart rate (before, during, and after surgery). However, the group receiving scalp block had higher ANI means than the control group.

CONCLUSIONS

Scalp nerve block has an effective role in pain control (increasing ANI), consequently reducing the need for analgesic drugs such as fentanyl and remifentanil following craniotomy without changing the hemodynamic condition.

Scalp Nerve Block, Local Anesthetic Infiltration, and Postoperative Pain After Craniotomy: A Systematic Review and Network Meta-analysis of Randomized Trials

The most efficacious methods for controlling postoperative pain in craniotomy remain unknown. A systematic review and network meta-analysis were performed to compare the efficacies of different strategies of scalp nerve block (SNB), scalp infiltration (SI), and control in patients undergoing craniotomy. MEDLINE, Embase, and CENTRAL databases were searched for randomized controlled trials. The primary outcome was postoperative 24-hour pain score, and the secondary outcome was opioid consumption within the first 24 hour after surgery. The effect was estimated using the between-group mean difference and ranked using the surface under the cumulative ranking curve (SUCRA) score. Twenty-four randomized trials were identified for inclusion. SNB using ropivacaine reduced postoperative 24-hour pain score when compared with control (mean difference [95% credible interval], -2.04 [-3.13, -0.94]; low quality), and when compared with SI using ropivacaine (-1.77 [-3.04, -0.51]; low quality) or bupivacaine (-1.96 [-3.65, -0.22]; low quality). SNB using ropivacaine was likely the most efficacious method for pain control (SUCRA, 91%), and also reduced opioid consumption within the first postoperative 24 hours as compared with control (mean difference [95% credible interval], -11.91 [-22.42, -1.4]; low quality). SNB using bupivacaine, lidocaine, and epinephrine combined, and SNB using ropivacaine, were likely the most efficacious methods for opioid consumption reduction (SUCRA, 88% and 80%, respectively). In summary, different methods of SNB / SI seem to have different efficacies after craniotomy. SNB using ropivacaine may be superior to other methods for postcraniotomy pain control; however, the overall quality of evidence was low.

Evaluating the Anatomic Spread of Selective Nerve Scalp Blocks Using Methylene Blue: A Cadaveric Analysis

BACKGROUND

The modern scalp block consists of local anesthesia injections that target the supraorbital, supratrochlear, zygomaticotemporal, auriculotemporal, and greater and lesser occipital nerves. Limited data exist on the local anesthetic spread that occurs with this technique. This study examines the extent of the spread of a scalp block using methylene blue in a cadaveric model.

METHODS

A traditional landmark-based scalp block was performed on 6 unembalmed human cadavers using 25-G, 1.5-inch needles to inject 1 to 2 mL of methylene blue 0.1% at each nerve bilaterally; a total volume of 20 mL was injected. The cadavers were then dissected, and the spread of injectate was measured and recorded.

RESULTS

All the nerves required for analgesic coverage were appropriately stained by the injections, except for in 2 specimens where the lesser occipital nerve could not be identified. The zygomatic (stained in 2 of 8 specimens) and temporal (stained in 5 of 8 specimens) branches of the facial nerve were stained as a result of the zygomaticotemporal and/or auriculotemporal injections. Tracking from the zygomatic injection site was noted as far inferior as the temporalis muscle attachments on the mandible.

CONCLUSIONS

This cadaveric study confirms that the landmark-based technique for scalp blocks consistently stained all 6 nerves involved in scalp innervation. There was significant unintentional spread to the branches of the facial nerve when using the landmark technique.

Dexmedetomidine as an adjuvant to scalp block in patients undergoing elective craniotomy: A prospective randomized controlled trial

OBJECTIVE

Regional techniques minimize anesthetic requirements and their effects may be beneficial. There is a lack of consensus and evidence concerning alternative analgesia strategies for cranial neurosurgery. This study was designed to evaluate the effect of scalp block with or without dexmedetomidine combined with general anesthesia on hemodynamic stability, opioid consumption and postoperative pain in patients undergoing elective craniotomy.

METHODS

One hundred five patients undergoing elective craniotomy for tumor dissection were randomly divided into three groups to receive scalp block as an adjuvant to general anesthesia: with either 40 ml ropivacaine 0.5 % (Group R), 40 ml ropivacaine 0.5 % plus dexmedetomidine 1 μg/kg (Group RD) or 40 ml saline as a placebo (Group C). After a standard induction sequence using propofol, fentanyl and a single dose of rocuronium, patients were intubated. Bilateral scalp block was given immediately after induction. Anesthesia was maintained with propofol and remifentanil infusion. Five minutes before head pinning scalp block was performed by blocking the supraorbital, supratrochlear, auriculotemporal, occipital, and postauricular branches of the greater auricular nerves. All patients were monitored with electrocardiogram, invasive blood pressure, pulse oximetry and BIS monitoring. Primary outcomes measures were overall hemodynamic variables during surgery and intravenous fentanyl and remifentanil consumption. Mean arterial pressure (MAP) and heart rate (HR) were recorded at seven time-points: scalp block (T1-baseline), pin fixation (T2), skin incision (T3), drilling (T4), dura matter incision (T5), dura matter closure (T6) and skin closure (T7). For all time points it was recorded the mean value after 3 consecutive measures with 5 min interval. Secondary outcome was postoperative pain intensity using visual analog scale 24 and 48 h after surgery. VAS scores, fentanyl and remifentanil were evaluated using Kruskal-Wallis test. MAP and HR were compared by One-Way repeated measures Anova (GLMM) using time as random efect and by One-Way Anova using time as fxed efect.

RESULTS

Mean arterial pressure was significant lower at skin closure compared to baseline in group R (p < 0,001) and in group RD (p < 0,001). Patients in group RD showed significant lower heart rate at dura matter incision, dura matter closure and skin closure compared to baseline, pin fixation and skin incision time points (p < 0,001) and reported significantly less heart rate than group C (p < 0,001) and group R (p < 0,001) during dura matter incision, dura matter closure and skin closure time points. Patients in group RD receive significant lower fentanyl than group R (p < 0,01). The intraoperative consumption of remifentanil was significant higher in control group compared to group R (p < 0,01) and to group RD (p < 0,001). Additionally, remifentanil consumption was significant lower in group RD as compared to group R (p < 0,001). Postoperative pain had no statistically differences between the three groups at 24 h and 48 h after craniotomy (Preop VAS: p = 0,915, VAS 24: p = 0,284, VAS 48, p = 0,385). No adverse effects were noted.

CONCLUSION

Our study indicated that addition of dexmedetomidine to scalp block with ropivacaine 0.5% provided significantly better perioperative hemodynamic stability during elective craniotomy. Moreover, scalp block with or without dexmedetomidine reduced fentanyl and remifentanil consumption, but it didn't significantly prolonged analgesia in patients undergoing elective craniotomy.

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.

The effectiveness of scalp nerve block on hemodynamic response in craniotomy: a systematic review and meta-analysis of randomized trials

INTRODUCTION

Strategies that blunt noxious stimuli and stabilize hemodynamics may reduce perioperative cardiovascular complications and enhance recovery after craniotomy.

EVIDENCE ACQUISITION

Our systematic literature review and meta-analysis investigated whether scalp nerve block (SNB) reduces the acute hemodynamic response compared with non-SNB (scalp infiltration or control) in adult patients undergoing elective craniotomy. We searched MEDLINE, EMBASE, CENTRAL, and two Chinese databases for randomized trials. Primary outcomes included mean arterial pressure and heart rate during skull pin insertion and surgical incision in craniotomy. Secondary outcomes included incidence of hypertension and dosage of intraoperative analgesic opioids used. Random-effects models were used for meta-analyses.

EVIDENCE SYNTHESIS

SNB significantly reduced the mean arterial pressure (mean difference: -14.00 mmHg; 95% confidence interval [CI]: -19.71 to -8.28) and heart rate (mean difference: -11.55 beat/min; 95% CI: -19.31 to -3.80), when compared with non-SNB during skull pin insertion. A similar trend was observed during skin incisions (SNB vs. non-SNB, mean difference in mean arterial pressure: -9.46 mmHg; 95% CI: -14.53 to -4.38; mean difference in heart rate: -9.34 beat/min; 95% CI: -15.40 to -3.28). Subgroup analysis showed that, compared with scalp infiltration, SNB reduced mean arterial pressure and heart during pin insertion but not during skin incisions. SNB also reduced the incidence of intraoperative hypertension, but no difference was observed in intraoperative opioid consumption when compared with non-SNB.

CONCLUSIONS

SNB alleviated the craniotomy-associated hemodynamic response. SNB may be superior to scalp infiltration in maintaining hemodynamic stability during pin insertion. However, high-quality trials are still needed to provide more conclusive evidence.

Comparison of effects of dexmedetomidine added to ropivacaine versus ropivacaine alone infiltration scalp block for attenuation of the haemodynamic response to skull pin placement in neurosurgical procedures: A double-blind, randomised clinical trial

BACKGROUND AND AIMS

Skull pin head holder application is intensely painful and is accompanied with abrupt increase in heart rate and arterial blood pressure. We aimed to determine the effects of adding dexmedetomidine to ropivacaine scalp block in attenuating the haemodynamic response to skull pin insertion in neurosurgical procedures.

METHODS

Sixty patients were randomly allocated to receive scalp block with 25 ml of 0.5% ropivacaine added with either normal saline (control group) or dexmedetomidine (1 μg/kg) after anesthesia induction. A standard uniform general endotracheal anaesthesia protocol was followed in all study subjects. Heart rate and blood pressure measurements were made at baseline, 1, 3, 5, 10, and 15 min following skull pin placement. Student's independent t-test, Chi-square test and repeated measure analysis of variance were used to analyse the obtained data.

RESULTS

There was no significant attenuation of heart rate (P = 0.418), systolic (P = 0.542), diastolic (P = 0.793) and mean blood pressure (P = 0.478) with addition of dexmedetomidine to ropivacaine.

CONCLUSIONS

The addition of dexmedetomidine (1 μg/kg) to 25 ml of 0.5% ropivacaine offers no additional benefit over 25 ml of 0.5% ropivacaine alone scalp block in attenuating the haemodynamic response to skull pin placement in neurosurgical procedures.

Preoperative Versus Postoperative Scalp Block Combined With Incision Line Infiltration for Pain Control After Supratentorial Craniotomy

OBJECTIVE

Postoperative pain after craniotomy is a significant clinical problem that is sometimes underestimated, although moderate or severe pain in early postoperative period complicates up to 60% of cases. The purpose of this prospective randomized multicenter trial was to determine the optimal timing for selective scalp block in patients undergoing general anesthesia for supratentorial craniotomy.

MATERIALS AND METHODS

After ethics committee approval and informed consent, 56 adult patients were enrolled, and randomly assigned to receive a selective scalp block combined with incision line infiltration preoperatively or postoperatively.

RESULTS

Postoperative pain at 24 hours after the procedure was recorded in all 56 enrolled patients. In patients assigned to receive a scalp block preoperatively, median VAS score at 24 hours after surgery was 0 (0 to 2), and in patients assigned to receive a scalp block postoperatively it was 0 (0 to 3) (P>0.05). There was no difference in severity of pain at 24, 12, 6, and 2 hours after surgery between the 2 study groups, but the amount of fentanyl administered intraoperatively was lower in patients assigned to the preoperative scalp block group (1.6±0.7 vs. 2.4±0.7 mkg/kg/h, P=0.01).

DISCUSSION

This study confirms and extends available clinical evidence on the safety and efficacy of selective scalp blocks for the prevention of postoperative pain. Recorded data suggest that there is no difference in terms of occurrence and severity of postoperative pain regardless of whether the scalp block is performed preoperatively (after general anesthesia induction) or postoperatively (before extubation). Patients assigned to receive a scalp block combined with incision line infiltration preoperatively needed less intraoperative opioids than those assigned to postoperative scalp block.

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.