Awake Craniotomy Without Bispectral Index Monitoring in a Rural Setting of Eastern Indonesia: A Case Report

Technical Summary: Awake Craniotomy Without Bispectral Index Monitoring in a Rural Indonesian Setting

Problem Statement
Awake craniotomy is the standard of care for resecting brain tumors involving eloquent cortex to minimize permanent neurological deficits. While Bispectral Index (BIS) monitoring is widely recommended to guide sedation depth and prevent intraoperative awareness or respiratory depression, these devices remain unavailable in most rural hospitals in low- and middle-income countries (LMICs) due to high procurement costs, maintenance constraints, and limited technical expertise. This gap is particularly acute in regions like Maluku Province, eastern Indonesia, where a single provincial referral center serves a geographically dispersed population without access to advanced neuromonitoring infrastructure. There is a lack of described, reproducible protocols for performing these complex procedures safely in resource-limited settings without electronic depth-of-anesthesia monitoring.

Methodology
The authors present a single-case report of a 36-year-old male (ASA II, 83 kg) undergoing an awake craniotomy for a left frontal high-grade glial neoplasm involving Broca's area at Siloam Hospital Ambon. The procedure utilized an asleep–awake–asleep protocol adapted for a resource-constrained environment:

• Sedation Strategy: Instead of BIS, sedation depth was titrated using the Ramsay Sedation Scale (RSS), targeting a score of 2–3 (cooperative, oriented, calm, and responsive to verbal commands).
• Pharmacological Regimen:
  • Dexmedetomidine: Administered as a loading dose of 1.0 mcg/kg over 15 minutes, followed by a maintenance infusion of 0.2–0.7 mcg/kg/hour.
  • Analgesia: A multimodal approach included a scalp block using 20 mL of a mixture (bupivacaine 0.5% 15 mL + lidocaine 2% 5 mL) targeting six nerve territories, supplemented by systemic opioids (fentanyl, pethidine) and local infiltration by the surgeon.
  • Hemodynamic Management: Intraoperative hypertension (SBP up to 165 mmHg) occurring without patient-reported pain was managed with IV clonidine (75 mcg) rather than additional dexmedetomidine to avoid oversedation.
• Preoperative Preparation: Structured counseling across two sessions covered the procedure, language tasks (naming, repetition, counting), and communication expectations.
• Monitoring: Standard monitoring (ECG, NIBP, SpO2, arterial line) was used; no electronic neuromonitoring was employed.

Key Results

• Clinical Outcome: The patient remained fully conscious, cooperative, and communicative throughout the cortical language mapping and tumor resection phases. No supplemental propofol or ketamine was required during the awake phase.
• Safety Profile: There were no episodes of respiratory depression, oxygen desaturation, or excessive sedation (RSS > 4). Two transient hypertensive episodes were successfully managed with clonidine.
• Postoperative Course: The patient was extubated immediately upon wound closure, admitted to the ICU for overnight monitoring, and discharged to the ward on postoperative day 1 with intact neurological function and no new deficits.
• Protocol Adherence: The team successfully maintained the target RSS of 2–3 through systematic clinical assessment and infusion titration, demonstrating that the "asleep–awake–asleep" approach is feasible without BIS.

Significance and Claims
The paper claims that awake craniotomy can be performed safely in rural LMIC hospitals without BIS monitoring by relying on specific, low-technology adaptations:

1. Pharmacological Precision: Accurate dosing of dexmedetomidine (loading and maintenance) is critical to avoid the 60-fold overdose risk associated with unit errors (mcg/kg/min vs. mcg/kg/hour).
2. Clinical Substitution: The Ramsay Sedation Scale serves as a validated, equipment-independent alternative to electronic monitoring when applied rigorously with frequent assessments.
3. Multimodal Analgesia: A comprehensive scalp block is essential to manage pain during pin fixation and incision, compensating for the lack of electronic feedback.
4. Reproducibility: The described protocol uses only medications available on Indonesia's national formulary and standard operating room monitoring, making it directly replicable in other resource-limited settings without capital expenditure.

The authors conclude that the absence of advanced neuromonitoring does not preclude safe, complex neurosurgical anesthesia when pharmacological precision and systematic clinical assessment replace electronic surrogates. They acknowledge limitations, including the single-case design and lack of postoperative MRI or definitive histopathology at the time of reporting, attributing these to the resource-constrained context rather than methodological choices.