JOURNAL OF IRANIAN SOCIETY ANAESTHESIOLOGY AND INTENSIVE CARE
Year:2005 | Volume:27 | Issue:49|Papers Count:13

Background and Objectives: Difficulty in tracheal intubation has always been a problem in both elective and emergency setting. The aim of this study was to compare the newly designed test, the Upper Lip Bite Test, (UIBT) with prevailing Tests - the Hyomental / Thyrosternal distances (HMD, TSD) and the Mandible length (ML) in predicting difficulty in intubation. Materials and Method: A total of 300 patients meeting the inclusion criteria were enrolled in this study. Each patient was assessed by a resident of anesthesiology, regarding the ULBT, HMD, TSD and ML, and laryngoscopy was performed by the anesthetics blinded to the measurements obtained and grading recorded using the Cormack and Lehane larynogoscopic grading system. The data obtained were analyzed using Chi square and ANOVA. Results: The results showed 11.3% incidence of difficult intubation. Sensitivity and specificity of ULBT were 94% and 100% respectively, being the highest compared to TSD which were the lowest being 88% and zero percent respectively ULBT class III had a direct correlation with HMD, <3.5 cm (p=0.00), and ML <9 cm (p=0.00).UIBT had the highest positive and negative predictive values (100% and 47%) respectively. Accuracy of ULBT was found to be 94%, again the highest among the four tests. Conclusion: In conclusion, ULBT was found to have the highest sensitivity and specificity and accuracy, and could be used as a single bed test in predicting difficulty in intubation.    

known as a mainstay in respiratory management of ARDS patients. Pressure controlled - inverse ratio (PC-IRV) with I/E=2/1 ventilation is another technique which can be used for respiratory management of these patients. AS there is still controversy in which technique is the best for respiratory management in ARDS patients, this study was done to compare the effect of CMV+PEEP and PC-IRV on pulmonary and hemodynamic parameters in ARDS patients. Materials and Method: In this prospective randomized clinical trial study, 50 ARDS patients requiring mechanical ventilation were divided into two groups. 25 of them underwent mechanical ventilation with CMV+PEEP (group 1) and the other 25 were ventilated with PCV-IRV technique (group 2). Ventilatory parameters (Vt, RR, PEEP, FiO2) and inspiratory flow waveform were kept constant in both groups. Mean arterial blood press Peak Inspiratory Pressure (PIP), Mean Airway Pressure (MAP), Plateau Pessure (Pplat), Peak Inspiratory Pressure (PIP), ABG, and PaO2/FiO2 were measured at first and sixth hours after the start of mechanichal ventilation in both groups and the results were compared to those obtained at hour zero. Results: PaO2 and PaO2/FiO2 were both increased at first and sixth hour of ventilatory support in both groups, and the PaO2/FiO2 obtained at the first and 6th hour was significantly higher in patients on PC-IRV compared to patients on CMV+PEEP. PIP was significantly less in PC-IRV group when compared to CMV + PEEP group at the first and 6th hour of ventilation. Pplat remianed less than 30 cm of water in PC-IRV group. MAP was increased insignificantly at first and 6th hour PC-IRV group. Mean arterial pressure was decreased insignificantly in both groups. Decrease of pulse pressure was significantly less in PC-IRVgroup at hour 6th in comparison to hour zero. Conclusion: In comparison to CMV+PEEP, PC-IRV technique increases oxygenation and decreases PIP in ARDs patients.    

Background and Objective: Laryngoscopy and tracheal intubation may be accompanied by tachycardia, hypertension, and mycocardial ischemia in susceptible individuals. Materials and Methods: In a single blinded study, we compared hemodynamic effects and recovery time of remifentanil and prpofol (group I) with alfentanil and prpofol (group 11)for anesthesia in cataract surgery. The study was clinical trial and single blinded. It was performed in 60 patients in ASA Class II assigned for elective cataract surgery under general anesthesia. They were allocated consequently into two groups. After receiving ringer solution 5 ml/kg, patients in group 1 received alfentanil 20, μg/kg and those in group 2 received remifentanil 1 , μg/kg each 30 seconds. Propofol was administered 1.5 mg/kg for induction of anesthesia and cisatracurium 0.15 mg/kg for ETintubation. Anesthesia was maintained in group I with propofol (50-100, μg/kg/min), and remifentanil (0.1 μg/kg/min) in group 2 to keep BIS in a range of 50-60), and alfentanil (1, μg/kg/min).SBP and HR of the patients were recorded at pre-determined times. Extubation time (ET) and recovery time (RT) were also recorded in both groups one hour after discharge from recovery room. The patients were asked for amnesia during anesthesia. Results: HR and SBP of patients reduced in the two groups after induction of anesthesia but this reduction was not significant (SBP: 114.89 mmHg in alfentanil group vs. 113.71 mmHg in remifentanil group; HR: 69.13 bpm in alfentanil vs. 65.42 in remifentanil group; (p>0.05). The hemodynamic changes were not significantly different between the two groups (p> 0.05). SBP and HR during laryngoscopy and intubation did not increase significantly (SBP: 114.23 mmHg in alfentanil group vs. 110.53 mmHg in remifentanil group: HR: 66.03 bpm in alfentanil vs. 63.50 in remifentanil group; (p>0.05). The extubation time and discharge time from the Recovery room were 10.7 (±1.94) and 13.93 (±73.85) minutes, and 5 (±1.94) and 7.03 (±1.89) minutes in group I and 11respectively (p> 0.005). None of the patients declared any recall of events that happened during the anesthesia. Conclusion: We concluded that the compound of propofol and remifentanil can be used as a safe substitute for the compound of propofol and alfentanil for eye surgery, without significant hemodynamic changes. We also found that the recovery time was shorter in the propofol and remifentanil group. The only problem concerning the widespread use of remifentanil is its higher price compared to alfentanil.      

Background and Objective: Electro convulsive therapy is an effective treatment in many psychiatric disorders such as major depression or schizophrenia. Hypertension, tachycardia myocardial ischemia or infarction and cerebrovasular accident are complications of ECT. We designed this clinical trial, prospective, double blinded; placebo controlled and crosses over study to compare cardiovascular effects of different remifentanil doses in standardized ECT. Materials and Method: 22 depressed patients were studied. Each patient received four times ECT which was given every other day. Before induction of anesthesia the patients were premedicated with 0.5 of atropine and one of the three doses of remifentamil (25, 50, 100 µg) or placebo. Anesthesia was induced with propofol 0.75 mg/kg and succinyl choline 1.2 mg/kg. Then electrical stimulation above the threshold was applied. We recorded heart rate (HR) systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial blood pressure (MAP). Before any drug administration, before electrical stimulation, at 1- minute intervals, and 12, 15, 20 , 25 minutes after ECT. The time of electroencephalographic convulsion, motor convulsion, recovery time, obeys of commands and spontaneous breathing was the same in all patients. Results: The peak HR after ECT was significantly lower in 100 μg group compared with the placebo group. We concluded that 100 μg remifentanil can modify hyperdynamic responses in ECT.      

Background and Objective: Postoperative pain accounts one of the most disturbing complications after various surgeries and could result in harmful physiologic consequence. Some investigators had reported that corticosteroids effectively induce and prolong the duration of local anesthetics. The aim of this study was to assess the efficacy of intravenous dexamethasone in prevalence and severity of postoperative pain. Materials and Method: In a randomized, double-blinded, placebo- controlled prospective study, 30 ASA I & 11, male above and under 50 years-old patients scheduled for elective surgical reconstruction of inguinal hernia under general anesthesia were enrolled and randomly assigned into control or case groups. Before induction of anesthesia, in control group, normal saline (2 ml) and in case group, dexamethasone (8 mg, 2 ml) was injected intravenously. The time between the ends of the surgery and pain beginning, occurrence and severity of postoperative pain by Visual Analoue scale (VAS) and the total postoperative administered analgesic dose were measured. Results: The age mean was 38.37±18.80. There were no significant defenses in means of age, surgery duration and fentanyl administration during surgery between control and case groups. The mean of pain severity (VAS) and the overall administered analgesic dose were significantly lower and time between surgery completion and pain initiation was significantly longer in case group compared to control group (p<0.05, Mann- Whitney Test). There were no significant differences between mentioned variables (except age) in above and under 50 years-old groups. In case group pain severity (VAS) was significantly higher over 50 years-old compared to under 50 years-old and the time between end of surgery and pain beginning was significantly longer (p<0.05, Mann-Whitney Test). Conclusion: Intravenous administration of 8 mg intravenous dexamethasone before induction of anesthesia significantly decreases the postoperative pain severity and the total administered analgesic and increases time betweeen the end of the surgery and pain beginning.      

Background and Objectives: Anesthesia clinic is a center for pre-operative evaluation and preparation of the patients. The aims of this clinic are obtaining the essential data and history of the patient, optimizing his/her condition in case of any co-existing disease before operation and selecting the best method of anesthesia on the day of surgery. Materials and Method: In an interventional pre-post study clinical and paraclinical procedures, bed day occupation and all related costs were evaluated and compared before and after establishment of anesthesia clinic in Labbafinezhad Hospital. The diagnostic procedures ( clinic), medical consultation, mean of bed-occupancy, day-admission, postponed operations and operation room related costs in the above 2 mentioned times were evaluated and compared. Results: There were no significant differences between 2 groups in terms of sex, ASA Class and type of surgery. The number of admitted patients in the year of 1998 was about triple that of the year of 2001 (2.11 days versus 0.55 days) (p= 0.000) Chest X-ray was ordered for 0.18% patients of 1998 group, whereas it decreased to 0 for 2001 group, the number of ordered medical laboratory exams in group 2 (2001) were significantly less than group 1 (1998). BUN (p=0.016), FBS (p=0.000), CBC (p=0.004), ESR (p=0.006), Creatinine (p=0.000), Urine analysis (p=0.000), Urine culture (p=0.000), Cholesterol (p=0.000), Triglyceride (p=0.000) Medical consultations in group 2 were less than group 1 (chi-squre= 154.7, p=0.000). The comparison of peri-operative costs in all aspects showed a decrease after establishing of anesthesia clinic (p<0.000). The anesthesia related postponed operations had been decreased to 0 in group 2. Conclusion: Regarding our findings, establishing the anesthesia clinic is essential and cost-effective.    

Background and Objective: The laryngeal mask airway has an important role in airway management in the operating room and also as an emergency airway adjunct in other locations. In common practice propofol and muscle relaxant are used for insertion of laryngeal mask, but propofol as a sole anesthetic is associated with undesirable airway responses such as coughing and gagging. In this study we evaluate the effect responses of remifentanil with propofol in decreasing these complications. Materials and Method: We performed a randomized double- blinded study to compare the hemodynamic changes and condition of insertion of LMA in 90 patients with ASA Class I, 11, in 3 groups. Group R1 (n=30) received 0.25 µg/kg remifentanil and 2.5 mg/kg propofol, group R2 (n= 30) 0.5 mg/kg remifentanil and 2.5 mg/kg propofol, and Group P (n=30) receive normal saline and 2.5 mg/kg propofol. Then hemodynamic changes, apneic time, condition of insertion mask and airway patency were compared between the three groups. Results: Remifentanil significantly improved the condition of insertion of mask in group R1: 80.33% (25.30), and group R2: 90.6% (29.30 (in comparison to group P: 40% (12.30). Hemodynamic changes in group R1 was less than R2. Patients in group R1 were apneic for 1.75±0.9 min in comparison to 2.35±1.3 min in group R2. Conclusion: Administration of 0.25 mg/kg remifentanil with 2.5 mg/kg propofol provides less hemodynamic changes and excellent condition for insertion of the LMA.      

Background and Objective: In order to reduce complications of tracheal intubation due to penetration of N20 into the tracheal tube cuff which increase cuff pressure and reduce perfusion of tracheal mucosa, we compared saline with air for inflation of the tracheal tube cuff. Materials and methods: In a .randomized double blind clinical trial study, 60 patients anesthetized by the same technique, allocated into two groups. In group A, air and in group S, saline was used for inflation of the tube cuff. At the end of anesthesia, tracheal mucosa under the cuff was observed by fiber optic laryngoscope, and mucosal lesions were evaluated. Incidence of sore throat, dysphagia and hoarseness on recovery and 24 hours later were recorded. Data were evaluated by Chi-square and independent sample T-test and p<0.05 was statistically considered significant. Results: Sever mucosal lesions (2nd degree) were 23.34% in group A and zero in group S. Zero and first degree lesions were 16.66%, 60% in group A versus 87.09% 12.91% in group S,  respectively (p=0.002). Mean of sore throat was 12.27% in group A versus 24.72% in the other group (p=0.56). Incidence of sore throat in recovery was 93.3% in group A and 77.4% in group S (p=0.65), but after 24 hours it was 83.3% and 29% respectively (p=0.001). Dysphagia and hoarseness was 86.6%, 43.3% in group A and 67.7%, 58% in group S, in recovery (p>0.05). After 24 hours, dysphagia and hoarseness were 40%, 23.3% in group A and 63%, 6.45% in group S respectively (p=0.04). Conclusion: Inflation of tracheal tube cuff with saline is a safe and effective method to reduce the complications of intubation after general anesthesia.