Journal of Clinical Anesthesiology: Open Access

Background: The purpose of this randomized observer-blinded clinical trial was to evaluate the utility of remifentanil compared with nitroglycerin for deliberate hypotensive anaesthesia throughout tympanoplasty.

Methods: Patients planned for elective typanoplasty under general anaesthesia were allocated to receive either intravenous infusion of nitroglycerin 2-5 μg/kg/min (group NTG), or remifentanil 0.2-0.5 μg /kg/min (group REMI). The primary outcome measures were to keep up MAP between 60 and 70 mmHg with ideal vision of operative site.

Results: Both studied agents induced deliberate hypotensive anaesthesia and achieved ideal vision of the surgical site by decreasing bleeding, but optimum vision was provided at reasonable hypotension (MAP 70-75) in group REMI however similar situation was provided at MAP 65–69 mmHg in group NTG.

Conclusion: Remifentanil and nitroglycerin are safe, efficient and might be advisable for deliberate hypotensive anaesthesia throughout tympanoplasty. However, remifentanil was superior as it provided optimum vision of the surgical site through decreasing intra operative bleeding with reasonable reduction in MAP, and mild tachycardia throughout tympanoplasty.

Study Objective: Delirium is an important complication after surgical intervention. One of the potential risk factors for cognitive disorders is deterioration in cholinergic neurotransmission including anticholinergic medications. We hypothesize that changes in blood cholinesterases (CHE) are associated with postoperative delirium.

Design: Prospective cohort study.

Setting: Postoperative delirium was assessed at least once daily in all included patients (n=103) preoperatively and on the first and third postoperative day during their stay on the intensive care unit (ICU) or in hospital.

Patients: undergoing a surgery on the head were included.

Interventions and Measurements: Postoperative delirium was assessed using the Intensive Care Delirium Screening Checklist (ICDSC). Blood samples were taken parallel to delirium testing and analyzed for serum anticholinergic activity (SAA) using radioactive competitive assay; acetyl- and butyrylcholinesterase activities (ACHE, BuCHE) were measured spectrophotometrically. Furthermore, patients’ characteristics and medication were recorded. Logistic regression analysis was used to evaluate potential predictors of postoperative delirium.

Main Results: Postoperative delirium was identified in 32% of patients and was associated with significant longer duration of surgery, prolonged artificial ventilation, and longer stays on the ICU and in hospital. In contrast to ACHE and SAA, a significantly reduced BuCHE (mean of n=3 time points ± SD, U/l) was associated with delirious patients (2918.9 ± 645) compared to non-delirious (3484.0 ± 928.4). Reduction in BuCHE was associated with a higher number of administered drugs with greater anticholinergic potency (≥ 1, classified according to the Anticholinergic Drug Scale).

Conclusion: Patients with reduced pre- or postoperative BuCHE activity are at higher risk for the development of postoperative delirium, this may be because of polypharmacy with anticholinergic drugs.

Highlights:

• Postoperative delirium was investigated in head and neck cancer patients.

• Delirium was associated with reduced pre- and postoperative BuCHE activity.

• Reduced BuCHE activity seems to be associated with polypharmacy of anticholinergic drugs.