Safety and Efficacy of Combined Epidural/General Anesthesia During Major Abdominal Surgery in Patients With Increased Intracranial Pressure

A Cohort Study

Igor Zabolotskikh; Nikita Trembach

Disclosures

BMC Anesthesiol. 2015;15(76) 

In This Article

Methods

The paper presents the results of a cohort study conducted in 65 surgical patients (mean age 67 (65–77) years) who were undergone elective major abdominal surgery for cancer (hemihepatectomy, gastrectomy, hemicolectomy, duodeno-pancreatic resection) (mean duration of surgery - 7 (4–9) hours). Physical status was the 3 class according to American Society of Anesthesiologists (ASA) classification. Exclusion criteria were life-threatening decompensated severe systemic diseases, the 4–5 ASA class; massive intraoperative bleeding; alcohol and drug abuse;. The exclusion criteria were also contraindications for epidural anesthesia, that is, patient refusal, local infection, bleeding diathesis.

ICP was evaluated in all patients preoperatively using ODM of the central retinal vein in a horizontal position after local anesthesia of the sclera with 2 % lidocaine hydrochloride and pupil dilation with 0.5 % solution of mydriacyl. Depending on the initial ICP all patients were divided into 2 groups: 1 (N group) - patients with the normal intracranial pressure (≤12 mm Hg, n = 35) and 2 (E group) – patients with the elevated intracranial pressure (ICP > 12 mm Hg, n = 30).[13] All patients had clear consciousness (Glasgow coma scale - 15 points).

All patients were NPO for at least 8 h before surgery and received 1 ml/kg normal saline (NPO deficit) per each NPO hour before induction as a part of fluid therapy in addition to the crystalloids used for the maintenance throughout the operation. All patients were placed on the operating table in a head up 15 degrees position, tracheal intubation in all cases was performed in a modified Jackson position. Introduction of anesthesia was performed in all groups with the following drugs: propofol (2 mg/kg), fentanyl (3 mkg/kg), non-depolarizing relaxant - atracurium (0.5 mg/kg). The infusion of propofol (6–12 mg/kg/h) was used in all patients to maintain anesthesia. The depth of anesthesia was controlled by the bispectral index, which was maintained at 40–60. An epidural catheterization was performed by a 18G Tuohy needle at Th8-Th10 before induction with the administration of 40 mg of lidocaine as a test dose. A bolus of 0.2 % solution of ropivacaine was injected to the epidural space (1 ml per spinal segment) followed by a continuous infusion (6–12 ml/h) for intraoperative analgesia. The infusion was continued postoperatively. Effectiveness of analgesia was assessed by a visual analogue scale (VAS) after awaking and then every 6 h for the first day. CPP was maintained at not less than 60 mm Hg. by the bolus administration of phenylephrine (25–50 mkg) or a continuous infusion of norepinephrine (0.8 % solution in a dose required to maintain arterial pressure, which usually does not exceed 0.1 mkg/kg/min). Mechanical ventilation was performed by Fabius or Julian (Draeger, Germany) and Blease Focus (Blease, UK) with the air-oxygen mixture (FiO2 – 0.4–0.5) to provide the normocapnia. The ventilation was corrected according to capnography data and arterial blood gas analysis with the 35–40 mm Hg target level of paCO2. All patients were actively warmed using a blowing warm air. The heart rate (HR, min-1), systolic (BPs, mm Hg) and diastolic (BPd mm Hg) blood pressure, mean arterial pressure (MAP, mm Hg) (Monitor Nihon Kohden, Japan) were among the studied haemodynamic parameters. The cerebral perfusion pressure (CPP) was calculated as the difference between the mean arterial pressure and intracranial pressure (CPP = MAP-ICP (mm Hg)). ICP measurement was performed on the following stages of anesthetic management: initially, after induction, and then every hour. The following parameters of recovery from anesthesia were evaluated postoperatively: time of consciousness recovery (the period from cessation of the anesthetic to spontaneous eye opening), time of full orientation recovery (the period from cessation of the anesthetic to the time when the patient can say the name and date of birth). A CAM-ICU scale was used to evaluate the patients for the purpose to diagnose delirium (daily until the patient's discharge from the hospital). The incidence of adverse postoperative events, the length of stay in the ICU and in the hospital was also evaluated.

Statistics. Continuous data with normal distribution are given as mean ± standard deviation, otherwise as median (25–75 percentiles). The independent t-test for testing the significance of mean for independent continuous scale (of normal distribution) data, Mann–Whitney for the significance of mean for non-normal distribution data, Chi-squared or Fisher exact test for testing the significance of percentages (qualitative data) were used. A p value <0.05 was considered significant.

This study was approved by the ethics committee of KSMU, Krasnodar. All patients provided written informed consent.

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