LETTER TO EDITOR
Year : 2013 | Volume
| Issue : 1 | Page : 107-108
As an analgesic ketamine versus fentanyl for total intravenous anesthesia
Musa Ezici1, Azize Bestas2, Omer Lutfi Erhan2
1 Departments of Anesthesiology and Reanimation, Special Osmaniye Sevgi Hospital, 80100-Osmaniye, Turkey
2 Firat University School of Medicine, 23119-Elazig, Turkey
Departments of Anesthesiology and Reanimation, Firat University School of Medicine, 23119-Elazig
Source of Support: None, Conflict of Interest: None
|Date of Web Publication||30-Mar-2013|
|How to cite this article:|
Ezici M, Bestas A, Erhan OL. As an analgesic ketamine versus fentanyl for total intravenous anesthesia. Saudi J Anaesth 2013;7:107-8
We read the article titled "Comparison of two drug combinations in total intravenous anesthesia: Propofol-ketamine and propofol-fentanyl" by Bajwa et al.  published in your esteemed journal with great interest. In their study, the researchers compared the anesthesia and recovery characteristics of two different total intravenous anesthesia application (TIVA) involving propofol-ketamine (Group I) or propofol-fentanyl (Group II) combinations. Although the results of the research concluded statistically significantly higher heart rate (HR), systolic and diastolic blood pressure values of the patients to whom propofol-ketamine was administered than the ones of the group to whom propofol-fentanyl was administered, it was determined to be clinically minimally higher. In addition, in the first 10 min of post-operative period, Group II was observed to have better recovery scores, and only 4% of the patients in Group I were observed to have post-ketamine sequelae.
We also conducted a similar study. Our study aimed to compare ketamine with fentanyl as a co-anesthetic agent at TIVA. After obtaining the Local Ethic Committee and the written informed consent, 60 male patients aged between 18 years to 60 years from American Society of Anesthesiology (ASA) physical status I-II who scheduled for elective inguinal hernia surgery were included in the study. Patients were randomly divided into four groups. Anesthesia was induced with midazolam (0.15 mg/kg) - ketamine (1 mg/kg) in Group midazolam-ketamine (MK), with propofol (1-2 mg/kg) - ketamine (1 mg/kg) in Group propofol-ketamine (PK), with midazolam (0.15 mg/kg) - fentanyl (3 μg/kg) in Group midazolam-fentanyl (MF), and with propofol (1-2 mg/kg) - fentanyl (3 μg/kg) in Group propofol-fentanyl (PF). Anesthesia was maintained with midazolam (0.15-0.4 mg/kg/h) - ketamine (0.01-0.02 mg/kg/h) in Group MK, with propofol (5-8 mg/kg/h) - ketamine (0.01-0.02 mg/kg/h) in Group PK, with midazolam (0.15-0.4 mg/kg/h) - fentanyl (0.05-0.10 mg, every 30 min) in Group MF, and with propofol (5-8 mg/kg/h) - fentanyl (0.05-0.10 mg, every 30 min) in Group PF. Depth of anesthesia was adjusted according to clinical responses. Vecuronium was used as a muscle relaxant in all groups Administration anesthetics was stopped about 10 min before the end of surgery (before the start of skin closure). HR, noninvasive mean arterial pressure (MAP), and pulse oximetry (SpO 2 ) were recorded at 12 time-points (from pre-anesthesia to postoperative 90 th min). As well as recovery characteristics of anesthesia, the severity of postoperative pain were also monitored by Visual Analogue Scale (score 0-10) at 15 th , 30 th , 45 th , 60 th , 75 th and 90 th min, postoperatively. In addition, blood samples were taken for determining serum adrenaline, noradrenaline, renin, aldosterone, adrenocorticotropic hormone (ACTH), glucose and cortisol levels at three time points (before and during anesthesia, 24 th h, postoperative). One-way ANOVA with Tukey Honestly Significant Difference, Chi-square or Fisher's exact tests were used for statistical analysis.
Demographic variables and surgical characteristics for all groups were similar. SpO 2 remained above 96% in all patients during both intraoperative and postoperative periods. During anesthesia induction, HR slightly increased in Group MK and PK whereas decreased in Group MF and PF, and MAP decreased in all groups, mostly in Group PF. Following induction of anesthesia, similar trend of HR and MAP was observed in all groups during maintenance of anesthesia and postoperative periods. Although, the values of Group PF were lower compared to other groups, hemodynamic values in all groups were in normal clinical limits. The difference between Group MK, and Group MF and PF was statistically significant only at the beginning of the surgery (P<0.05). After discontinuation of anesthetic agents, the mean times for motor response to noxious stimuli (MRNS) and verbal stimuli (MRVS), and verbal response to verbal stimuli (VRVS) were longer in Group MK and PK than in Group MF and PF. Although Group PF had the shortest mean times for MRNS, MRVS and VRVS (5.6 min, 8.7 min, and 11.7 min, respectively), Group MK had the longest mean times for MRNS, MRVS and VRVS (7.5 min, 11.5 min, and 15.4 min, respectively). In addition, in terms of recovery characteristics and rates of side effects, there was no statistically significant difference between groups. Course of change in serum hormones levels was similar, and there was no significant difference between groups (P>0.05). During anesthesia, serum adrenaline, noradrenaline (significantly in Group PK compared to Group PF P<0.01), ACTH, glucose and cortisol levels increased; however, serum aldosteron and rennin levels decreased in all groups. Although statistically not significant, nausea was observed in the fentanyl administered patients (20%) and non-intense psychometric reactions were observed in ketamine-administered patients (approximately 13%) at higher rates (P>0.05).
TIVA is provided with an intravenous hypotonic agent, mostly propofol and rarely midazolam, and an opioid. Recently, there is a great interest in the use of ketamine, a phencyclidine derivative, instead of opioids for TIVA due to its significant analgesic characteristic. , Ketamine has significant analgesic, hypotonic and amnesic effects in anesthetic dosages (1-2 mg/kg, i.v.) and analgesic effects in subanesthetic dosages (0.1-0.5 mg/kg). In addition, it prominently increases arterial blood pressure, HR and cardiac output secondarily to direct stimulation of sympathetic nervous system. It has bronchodilator effect as well as minimal respiratory depression. In addition, ketamine may lead to an increase in salivation and unpleasant psychotomimetic reactions such as hallucinations, nightmares during early recovery period.  Cardio-vascular stimulation and especially unpleasant psychotomimetic effects of ketamine limit its usage. Use of benzodiazepines or propofol may decrease both dosage requirement of ketamine and its adverse effects.
The findings of our study indicate that the combination of ketamine at subanesthetic dosage with both midazolam and propofol provides acceptable TIVA and recovery period at similar quality with other combinations with fentanyl. Differently from our study, Bajwa et al.  combined propofol at low dose (2 mg/kg/sa) with ketamine at anesthetic dosage (2 mg/kg/sa). Nevertheless, both in their study and our study, increases in hemodynamic parameters in ketamine groups compared with fentanyl groups were at minimal level and insignificant. Although fentanyl administered patients had better recovery characteristics than ketamine applied patients, recovery periods of all groups were comparable. In the conclusion part of their article, Bajwa et al. state that both propofol-ketamine and propofol-fentanyl combinations provided pleasant and safe anesthesia. We agree with the authors that ketamine can be an alternative to fentanyl as an adjunct to TIVA.
| References|| |
|1.||Bajwa SJ, Bajwa SK, Kaur J. Comparison of two drug combinations in total intravenous anesthesia: Propofol-ketamine and propofol-fentanil. Saudi J Anaesth 2010; 4:72-9. |
|2.||Gray C, Swinhoe CF, Myint Y, Mason D. Target controlled infusion of ketamine as analgesia for TIVA with propofol. Can J Anaesth 1999;46:957-61. |
|3.||Vallejo MC, Romeo RC, Davis DJ, Ramanathan S. Propofol-ketamine versus propofol-fentanyl for outpatient laparoscopy: Comparison of postoperative nausea, emesis, analgesia, and recovery. J Clin Anesth 2002;14:426-31. |
|4.||Revers JG, Glass PS, Lubarsky DA, McEvoy MD, Martinez-Ruiz R. Intravenous Anesthetics. In: Miller RD, editor. Miller's Anesthesia. 7 th ed, Vol. 1. Philadelphia, USA: Churchill Livingstone; 2010. p. 719-68. |
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