Optimal Dose of Intravenous Oxycodone for Endotracheal Intubation

Intravenous form of oxycodone is recently used for the adjunct of anesthetic agents to avoid adverse effects of the stimulation of endotracheal intubation. The potency ratio of oxycodone to fentanyl is not absolutely defined. The aim of this study was to assess the optimal dose of intravenous oxycodone for attenuation of hemodynamic responses to laryngoscopy and endotracheal intubation.

A prospective, randomized, double-blind study was conducted. Ninety one patients were randomly divided into 5 group based on the dose of oxycodone; 0, 0.05, 0.1, 0.15, 0.2 mg/kg. After giving each assigned dose of intravenous oxycodone, anesthesia was induced with thiopental and rocuronium. Heart rate (HR) and blood pressure (BP) was collected at baseline, before intubation, 1, 2, 3 minutes after intubation. The change of BP was calculated by (highest BP after intubation - baseline BP)/baseline BP.

Endotracheal intubation is almost always associated with increase of catecholamine and arterial blood pressure. To prevent the responses to laryngoscopy and tracheal intubation, adjuvant use of opioid to sedative drugs during anesthetic induction phase are common. Intravenous form of oxycodone is recently used for the adjunct of anesthetic agents to avoid adverse effects of the stimulation of endotracheal intubation. However, The potency ratio of oxycodone to fentanyl is not absolutely defined. Therefore, the investigators aimed to assess the optimal dose of intravenous oxycodone for attenuation of hemodynamic responses to laryngoscopy and endotracheal intubation.

The patients were randomly divided into five different groups based on the dose of oxycodone; 0. 0.05, 0.1, 0.15, 0.2 mg/kg. The drug was prepared by a person who is not participating the anesthetic management and surgery of the patient. In five groups, the drug was mixed with normal saline which makes the total drug volume to be 10 ml. After monitoring was started including ECG, noninvasive blood pressure, and pulse oximetry, the anesthesiologist who has no information about the drug give the drug when starting induction of anesthesia. Thiopental 4-5 mg/kg and rocuronium 0.6-0.9 mg/kg was given subsequently. Manual ventilation was done with sevoflurane 3-5 volume% for 2-3 minutes and tracheal intubation was done. Maintenance of anesthesia was done with 50% O2 with nitrous oxide and sevoflurane. Mechanical ventilation was done with tidal volume 10 ml/kg and respiratory rate 12 /min. The baseline hemodynamic data including heart rate and blood pressure was recorded and those before intubation, 1,2,3 minutes after intubation were obtained. The discrepancies between the highest and baseline, the lowest blood pressure and heart rate and baseline were used to make out the proportion of hemodynamic changes. This proportion of the hemodynamic changes were compared in five groups. In addition, the use of vasopressor was also recorded and the frequency and the cumulative dose was compared among the groups.

Eligibility Criteria:
Inclusion Criteria:

* American Society of Anesthesiologists (ASA) class 1

Exclusion Criteria:

* ASA class over 2
* expected difficult intubation
* intubation time over 30 seconds
* intubation trial was more than once