Scalp Block versus Local Infiltration Anesthesia for Skull-Pin Placement in DBS Surgery: Better Hemodynamics and Less Antihypertensive Medication?

Aim: In awake deep brain stimulation (DBS) surgery, acute high blood pressure (BP) is a major risk factor for intracranial bleeding. To minimize pain and hypertensive conditions, sufficient local anesthesia is mandatory that does not interfere with intraoperative assessments. In this study, we evaluated whether local instillation of anesthetics (LA) or a scalp block (SB) prior to frame fixation could improve intraoperative analgesia and hemodynamics and reduce the dose of analgesics as well as antihypertensive medication. To our knowledge, this is the first study to compare both methods during awake DBS surgery.

Methods: Intraoperative cardiovascular parameters and perioperative medication of 47 patients who underwent DBS surgery were retrospectively analyzed (LA, n = 29; SB, n = 18). Primary study end points were intraoperative systolic BP (means, peaks ≥ 160 mm Hg) and heart rate. Secondary end points were use of intraoperative antihypertensive medication and perioperative analgesics.

Results:: Patients with SB showed significantly lower mean systolic BP values (LA 153.7 ± 2.2 mm Hg vs SB 140.7 ± 3.4 mm Hg; p = 0.001) and hypertensive peaks ≥ 160 mm Hg (LA 37.7 ± 4.6% vs SB 13.4 ± 3.0%; p = 0.013) during the first 2 hours of surgery when compared with LA patients. Patients with LA required significantly higher doses of antihypertensive urapidil to stabilize BP than SB patients (LA 20.5 ± 3.9 mg/h vs SB 3.4 ± 0.6 mg/h; p < 0.001). No patients treated with SB had intracranial bleedings as opposed to two hemorrhage cases in LA patients. The intraoperative dose of remifentanil was significantly higher in SB patients (LA 0.0 ± 0.0 mg/h vs SB 0.04 ± 0.02 mg/h; p = 0.04), whereas the doses of paracetamol and metamizole showed no significant difference between the two groups. When the impulse generator (IPG) was implanted the same day, SB patients needed significantly less remifentanil during the second intervention (LA 0.583 ± 0.049 mg/h vs SB 0.223 ± 0.044 mg/h; p = 0.003).

Conclusion: Our data suggest that SB might be superior to LA for DBS surgery with respect to BP control. Intraoperative need for remifentanil was higher in the SB group during the first procedure and lower during the second procedure when the IPG was implanted the same day. Larger prospective, randomized, and controlled studies are needed to finally confirm the promising present study results.