Comparison of Propofol-remifentanil with Thiopental-remifentanil for Tracheal...

[Full title: Comparison of Propofol-remifentanil with Thiopental-remifentanil for Tracheal Intubation Without Using Muscle Relaxants, a Double Blind Randomized and Clinical Trial Study]

Life International Journal of Pharmacology ISSN 1811-7775 Life science alert ansinet Asian Network for Scientific Information

International Journal of Pharmacology 2 (2) 265-267, 2006 ISSN 1811-7775 2006 Asian Network for Scientific Information Comparison of Propofol-remifentanil with Thiopental-remifentanil for Tracheal Intubation Without Using Muscle Relaxants, a Double Blind Randomized and Clinical Trial Study Sussan Soltani Mohammadi and Farhood Tofighi Department of University of Medical Sciences, Tehran, Iran Abstract: In this study, we compared propofol + remifentanil with thiopental + remifentanil without using muscle relaxant for hemodynamic responses and intubation conditions in 100 ASA, Class I and II patients were randomly assigned to two equal groups. After premedication with midazolami 0.03 mg kg intravenously, remifentanil 1 ug kg were given in each group. In Group I, propofol 2.5 mg kg and in Group II, thiopental 5 mg kg were given intravenously. After 90s, trachea was intubated. Intubation conditions were classified by the anesthesiologist performing the intubation as: excellent, good, fair and poor. Systolic, mean, diastolic arterial blood pressure and heart rate were recorded as baseline, after the induction and 1, 3, 5, 10, 15 min after the intubation. Data were analyzed by Chi-square, independent t-test, paired t-test and repeated measures ANOVA. p<0.05 was statistically significant. The tracheal intubation conditions were excellent in 60%, good in 32% and fair in 16% of Group I and 12, 12 and 16% in Group II, respectively (p = 0.166). The difference in hemodynamic changes in each group and between the two groups were statistically significant (p = 0.001). In Group I, 52% and in Group II, 24% need intravenous ephedrine for treatment of hypotension (p = 0.004). Atropine were given intravenously in 4 patients of Group I and non of Group II for bradycardia (p-0.059). The results suggest that propofol 2.5 mg kg remifentanil 4 µg kg ' compared with thiopental 5 mg kg | | remifentanil 4 µg kg ' has no priority for tracheal intubation condition but with more hemodynamic changes. Key words: Tracheal intubation, remifentanil, propofol, muscle relaxant. INTRODUCTION Tracheal intubation is usually facilitated by administration of a muscle relaxant to supplement drugs given for the induction of anesthesia. Neuromuscular blocking drugs and their antagonists have potential side effects that may result in slower recovery. Also in many surgeries, muscle relaxation is undesirable or not required. Remifentanil is an ultra short acting opioid, which effectively attenuates the hemodynamic responses to laryngoscopy and tracheal intubatio (Glass et al., 1999). The trachea can be reliably intubated without a neuromuscular block in patients who have received remifentanil followed by propofol (Klemo et al., 2000). Also remifentanil with thiopental may be useful for tracheal intubation when neuromuscular block is not induced (Mahmut et al., 2003). In some studies propofol was superior to barbiturates in decreasing muscle tone and abolishing laryngeal response to tracheal intubation (Brown et al. 1991; Hovorka et al., 1991; Steven et al., 1997). We designed a randomized double-blind clinical trial study to compare the intubation conditions and hemodynamic responses of patients after induction of anesthesia by propofol 2.5 mg kg + remifentanil with thiopental 5 mg kg + remifentanil without using muscle relaxants. 4 μg kg 4 ug kg MATERIALS AND METHODS This clinical trial was performed in Dr. Shariati IIospital of Tehran University of Medical Sciences in 2001. After the Institutional Review Board approval and informed consent were given, 100 ASA physical status I and II patients aged 15-60 years, scheduled for elective surgeries under general anesthesia shorter than one hour duration were admitted to the study. The patients were randomized into two equal groups by a computergenerated randomization list that was drown up by the statistician and the sequence was concealed until interventions were assigned Exclusion criteria included a history of hypertension, asthma or allergic reactions, drug or alcohol abuse, coronary artery disease and predicted difficulty in intubation or airway maintenance. After starting standard monitoring of ECG, NIBP and pulse oximeter, all patients were given 5 ml, kg¯¹ normal saline 0.9% and premedicated with midazolani 0.03 mg kg IV, approximately 10 min before the induction Corresponding Author: Sussan Soltani Mohammadi, Anesthesology and Intensive care Medicine, Dr. Shariati Hospital, Telman University of Medical Sciences, North Kargar Ave, Tehran, Iran Tel: 198-21-22295296, 98-912-1226683 Fax: 98-21-88633039 265

Int. J. Pharamacol., 2 (2): 265-267, 2006 Table 1: Scoring criteria for conditions of intubation Grade Excellent Good Tair Poor Scoring Criteria Flaccid relaxation of jaw muscles, good cord visualization, cord well separated-abducted, no bucking Jaw muscles well relaxed, good cord visualization, slight cord movement, minimal bucking Conditions less favorable, jaw muscle relaxed, cord visualization fair but allowing intubation, bucking on intubation Poor relaxation of jaw, poor cord visualization, unable to intubate or if intubated marked bucking and body movement. of anesthesia in the operating room. Then remifentanil (Vial 2 mg, Ultiva M,Glaxowellcome) 4 µg kg were given over 30 sec. In Group I, propofol (Amp 10 mil, propofol- "lipuro1%, B.Brown Melsungen AG) 2.5 mg kg¯¹ and in Group, thiopental (Vial thiopental 1 g, SANDOZAustria) 5 mg kg were given intravenously for induction of anesthesia. The coded test syringes of the induction agents were prepared by an independent anesthesiologist. in a total volume of 20 mL with envelopes, therefore, all of anesthesia personnel were blinded to the induction agents. Patients were ventilated manually with 100% oxygen, ninethy seconds after completion of drug administration, laryngoscopy and tracheal intubation were attempted by one anesthesiologist, using macintosh 3 laryngoscope blade and a 7.5 or 8 mm endotracheal tube for women and men respectively. The anesthesiologist performing the intubation assessed and scored each patient's condition at laryngoscopy and tracheal intubation using criteria in Table 1. Patients who could not be intubated on the first allempl, were given succinylcholine 1 mg kg IV and intubation was completed. Anesthesia was maintained with 0.7% halothane and 50% NO. Hypotension (mean arterial blood pressure [MA] <25% from baseline for 60 sec) was treated with ephedrine 5-10 mg IV. bradycardia (heart rate [HR] <<50 bpm for 60 sec if hypotension occur) was treated with atropine 20 μg kg IV. Heart rate (HR), systolic arterial blood pressure (SAP) and diastolic arterial blood pressure (DAP) were recorded as baseline (before any instrumentation), after induction and 1, 3, 5, 10 and 15 min after the intubation 1 For sample size calculation we considered excellent and good condition as acceptable and fair and poor as non acceptable condition. Sample size was calculated to detect 20% difference in percentile of acceptable tracheal intubation condition with c = 0.05 and statistical power of 0.8. Statistical analysis was performed With SPSS package (SPSS Inc, Chicago, IL, USA). Data were analyzed by independed t-test, Chi-square or fisher exact test and repeated measures ANOVA when appropriate. p<0.05 was considered statistically significant. RESULTS There were no significant differences in patient's demographic data between the two groups, Table 2 (p>0.05, independed t-test). Table 2: Comparing demographic data between the two gmups Age (year) Sex (M/F) Weight (kg) Group I 50) 34.2+9" 18/32 65.2±10.1* Group In 50) 39-5" 30/20 |.3=:5. 3* "mcan+SD, There were no significant differences between groups. 70 60 50 40 30 20 10 0 Excellent Propofol and remifentanil Thiopental and remifentanil Good Fair Fig. 1: Distribution of patients in different intubation conditions The tracheal intubation conditions were considered excellent in 30(60%) patients, good in 16(32%) and fair in 1(16%) patients of Group I and were excellent in 21(12%), good in 21(42%) and fair in 8(16%) patients of Group II respectively (p = 0.166, Chi-square). Poor condition did not observe in any group. The percentage of tracheal intubation conditions is shown in Fig. 1. In Group 1, 52% and in Group 1, 24% needed intravenous ephedrine for treatment of hypotension (Chi-square, p = 0.004). Atropine were given in 4 patients of Group 1 and none of Group 11 for bradycardia (fisher exact test, p = 0.059). Hemodynamic changes in MAP and HR were significant in cach group and between the two groups (repeated measures ANOVA, p<0.05). In Propofol + remifentanil group there was more decrease in MAP, Fig. 2 HR did not increase in any group after intubation (Fig. 2). DISCUSSION Results of this study suggested that propofol 2.5 mg kg remifentanil 4 ug kg¯ compared with thiopental 5 mg kg + remifentanil 4 µg kg¯¹ had no statistically difference for tracheal intubation condition in 266

Heart rate (beat/min) Intl. J. Pharamacol., 2 (2): 265-267, 2006 100 -- Induction Propofol + Remifentanyl --Thipoental + Remifentanyl 110 100 90 80- 70- 60 Base Induction 1 min 3 min 5 min 10 min 15 min Time -- Induction Propofol + Remifentanyl --Thipoental + Remifentanyl Although remifentanil more than 1 µg kg¯ is associated with clinically muscle rigidity, no patient. manifested signs of rigidity in our study that was correlated with findings of Steven et al. (1997). When remifentanil co-administered with a hypnotic drug, may nol cause muscle rigidity (Steven and Wheatly, 1994). Furthermore, pretreatment with benzodiazepines may be effective in preventing opioid induced muscle rigidity (Sunford et al., 1994). In summary, our results suggested that remifentanil 4 µg kg + propofol 2.5 mg kg compared with remifentanil 1 µg kg + thiopental sodium 5 mg kg¯ provide no better condition for tracheal intubation and is associated with more hemodynamic changes in propofol group. So it is recommended for tracheal intubation with opioids and hypnotic agents without relaxants, to use appropriate induction agent. AKCNOWLEDGEMENT using muscle With special thanks to development Research Center of Dr. Shariati Hospital for statistical consult. Mean arterial pressure (mm Hg) 90 80 70 60 Base Induction 1 min 3 min Time 5 min 10 min 15 min Fig. 2 Ileart Rate (IIR) and Mean Arterial Pressure (MAP) responses to induction agents and intubation; base before any instrumentation, induc after bolus dose of hypnotic agent, 1 min one minutes after intubation, 3 min three miles aller intubation; 5 min 5 min aller intubation, 10 min 10 min after intubation, 15 min 15 min after intubation healthy premedicated patients with favorable anatomy. These findings did not correlate with the findings of Brown et al. (1991) that observed propofol is superior to barbiturates in decreasing muscle tone and abolishing laryngeal response to tracheal intubation. Propofol + remifentanil were associated with more decrease in MAP and HR but, HR decrease after the first minute of intubation and then increase compared with thiopental group which supports the findings of IIovorka et al. (1991). REFERENCES Glass, P.S.A., T.J. Gan and S. Howell, 1999. A review of pharmacokinetics and pharmacodynamics of remifentanil. Anesth. Analg., 89: 7-14. Klemola, U.M., S. Mennander and L. Saarinvaara, 2000. Tracheal intubation without use of muscle relaxants: Remifentanil or alfentanil in combination with propofol. Acta Anesthesiol. Scand., 11: 65-69. Mahmut, D., E. Gedik, A. But, G.N. Kadir and E. Ozturk, 2003. Remifentanil with thiopental for tracheal intubation without muscle relaxants. Anesth Analg.. 96: 1336-1339. Brown G.W, N. Patel and F.R. Ellis, 1991. Comparison of propofol and thiopental for laryngeal mask insertion. Anesthesia 46: 771-772. Hovorka, J., P. Honkovaara and K. Kartilla. 1991. Tracheal intubation aller induction of anesthesia with thiopental or propofol without muscle relaxants. Acta Anesthesiol. Scand. 35: 326-328. Steven, J., M.V. Vercovo and K. Harris, 1997. Trachcal intubation using alfentanil and no muscle relaxant is the choice of hypnotic important. Anesth Analg., 87: 1222-1226. Steven, J.B., L. Wheatley, 1998. Tracheal intubation in ambulatory surgery patients: Using remifentanil and propofol without muscle relaxants. Anesth Analg., 86: 45-49. Sunford, T.J. Jr., M.B. Weinger and N.T. Smith, 1994. Pretreatment with sedativehypnotics but not with nondepolarizing muscle relaxant, attenuates alfentanil induced muscle rigidity. J. Clin. Anesth., 8: 473-480. 267