Anaesthesia for awake craniotomy: A retrospective study of 54 cases

Abstract

Background and Aims:The anaesthetic challenge of awake craniotomy is to maintain adequate sedation, analgesia, respiratory and haemodynamic stability in an awake patient who should be able to co-operate during intraoperative neurological assessment. The current literature, sharing the experience on awake craniotomy, in Indian context, is minimal. Hence, we carried out a retrospective study with the aim to review and analyse the anaesthetic management and perioperative complications in patients undergoing awake craniotomy, at our centre.Methods:Medical records of 54 patients who underwent awake craniotomy for intracranial lesions over a period of 10 years were reviewed, retrospectively. Data regarding anaesthetic management, intraoperative complications and post-operative course were recorded.Results:Propofol (81.5%) and dexmedetomidine (18.5%) were the main agents used for providing conscious sedation to facilitate awake craniotomy. Hypertension (16.7%) was the most commonly encountered complication during intraoperative period, followed by seizures (9.3%), desaturation (7.4%), tight brain (7.4%), and shivering (5.6%). The procedure had to be converted to general anaesthesia in one of patients owing to refractory brain bulge. The incidence of respiratory and haemodynamic complications were comparable in the both groups (P > 0.05). There was less incidence of intraoperative seizures in patients who received propofol (P = 0.03). In post-operative period, 20% of patients developed new motor deficit. Mean intensive care unit stay was 2.8 ± 1.9 day (1–14 days) and mean hospital stay was 7.0 ± 5.0 day (3–30 days).Conclusions:‘Conscious sedation’ was the technique of choice for awake craniotomy, at our institute. Fentanyl, propofol, and dexmedetomidine were the main agents used for this purpose. Patients receiving propofol had less incidence of intraoperative seizure. Appropriate selection of patients, understanding the procedure of surgery, and judicious use of sedatives or anaesthetic agents are key to the success for awake craniotomy as a procedure.

Anaesthesia Management for Awake Craniotomy: Systematic Review and Meta-Analysis

“…Data of the study characteristics are shown in Table 1 . A total of fourteen case series [ 10 , 17 , 19 , 20 , 23 , 28 , 39 , 41 , 44 , 47 , 51 , 53 , 54 , 60 ] thirteen prospective studies [ 18 , 21 , 22 , 25 – 27 , 30 , 33 , 35 , 38 , 52 , 55 , 61 ], seventeen retrospective studies [ 24 , 29 , 31 , 34 , 37 , 40 , 42 , 43 , 45 , 46 , 48 – 50 , 57 – 59 , 62 ], two RCTs [ 32 , 56 ], and one pseudo-RCT [ 36 ] comprising 5945 AC procedures in 5931 patients were analysed ( Table 1 ). Of note, during the data extraction process it appeared that nine studies [ 20 , 22 , 27 , 31 , 42 – 46 ] partially repor...…”

“…Three studies continued conscious sedation with propofol in a reduced dosage also during the awake phase [ 18 , 32 ], and the awake anaesthesia management is unknown for six studies [ 19 , 35 , 55 , 58 , 61 , 62 ]. Dexmedetomidine (around 0.1–0.7 μg kg -1 h -1 ) was continued in totally 36 procedures during the "awake" phase [ 48 , 59 , 60 ]. It could be shown, that dexmedetomidine has a minimal interference with electrocorticography (ECoG) during AC in a dosage of 0.2–0.5 μg kg -1 h-1 [ 60 ].…”

“…MAC for AC was also used efficaciously in five elderly patients (>60 years), with complex co-morbidities [ 28 ]. Intraoperative hypoxia was reported for five patients [ 36 , 59 ], but all cases could be resolved with simple dose reduction and oxygen application. One large retrospective study (n = 611) used all possible combinations of propofol, remifentanil and dexmedetomidine in patients with significantly different baseline characteristics [ 34 ].…”

“…Of note, we did not include data of patients with deterioration of a pre-existing neurological dysfunction. Twenty-nine studies [ 10 , 18 , 19 , 23 , 24 , 28 , 29 , 31 , 33 – 35 , 37 , 38 , 40 – 43 , 48 , 49 , 51 – 55 , 57 – 59 , 61 , 62 ] reported new postoperative neurological dysfunctions after 565 (14.0%) of totally 4029 AC procedures. A later follow up result (six months) was provided for 279 of these patients with new neurological dysfunction.…”

“…Of note, late neurological outcome after six months was reported in only seventeen studies comprising 2085 AC procedures in total. Considering twenty-six studies [ 10 , 18 , 19 , 23 , 24 , 28 , 29 , 34 , 35 , 37 , 38 , 40 , 41 , 43 , 48 , 49 , 51 – 55 , 57 – 59 , 61 , 62 ], which were reasonable included in our meta-analysis, the proportion of new neurological dysfunction was estimated to be 17% [95%CI: 12–23], with a high heterogeneity (I 2 = 90%) ( Fig 5 ). Meta-regression analysis did not reveal a difference depending on the anaesthesia technique (MAC/ SAS) (QM = 1.52, df = 1, p = 0.217), with an OR of 1.66 [95%CI: 1.35–3.70].…”