JOURNAL OF IRANIAN SOCIETY ANAESTHESIOLOGY AND INTENSIVE CARE
Year:2003 | Volume:24 | Issue:43|Papers Count:10

The effects of positive ventilation on hepatic elimination of phenytion with low extraction ratio characteristic have not yet been studied. In an observational prospective study, seven patients with Traumatic Brain Injury (4 females & 3 males), older than 18 years old, GCS<8, intubated with Acute Lung Injury (pao2/Fio2 <300) & without any history of hepatic, renal, cardiac diseases, not reciveing phenytion & drugs affecting phenytion metabolism, were included. The mean (±SD) for age, CLer & Alb were 45± 21 years, 144± 58 ml/min & 3.7±55 ml/min. The mean & range for height, weight, ideal body weight & APACHE II were 167 (160-175) cm, 64(55-70) kg, 63(54-73)kg & 21(12-28) respectively. For our intubated & mechanically ventilated Traumatic Brain Injury patients, we considered 0 MAP b.p.e=108.72± 10.62 mmHg, MAP a.p.e=114.48± 8.11 mmHg P.value=0.32 MAP=Mean arterial pressure Ctrough b.p.e=12.57± 1.99 mg/l, Ctrough a.p.e=10.42± 3.63 mg/I. P.value=0.09 In the presence of MAP elevation Ctrough b.p.e=17.82±7.27 mg/l, Ctrough a.p.e=22.95± 4.43mg/I P.value= 0.23 In the presence of MAP elevation maxalue=0.25 In the presence of MAP elevation Vrnaxb.p.e= 6.85± 0.23mg/kg/d, Vmax a.p.e= 7.28± 0.85 mg.kg/d Vmaxb.p.e= 6.48± 2.16mg/kg/d, Vmaxa.p.e=6.15±1.81 mg.kg/d P.value= 0.41 In the presence of MAP reduction We concluded that although there is not any statistically significant correlation between mean arterial pressure (MAP) & pharmacokinetic key paramaters of phenytoin following PEEP elevation (Pvalue>0.05), but clinically PEEP can cause MAP to be increased, leading to increasing & Decreasing of Vmax& Ctrough respectively & vice versa.

Considering the existing conflicted results of previous studies regarding to the effect of midazolam on IOP, we decided to study the effect of midazolam premedication on intraocular pressure (lOP).In a double blinded clinical trial, 40 patients ASAI, (50-70 years old), that were scheduled for cataract extraction under general anesthesia were divided into two separate groups, study group (A) in which patients received midazolam 0.03 mg/Kg IV as premedicatin and control group (B) in which patients received 2ml normal saline as a placebo at random. At regular intervals, the changes in vital signs and lOP were measured.In the study group, lOP decreased about 8.4% whereas; it increased almost 9.4% in control group (p<0.05). Likewise, the changes of vital signs in the two groups were in reverse direction (increase in control group vs. decrease in study group); systolic blood pressure 6.7% increase vs. 10% decrease, diastolic blood pressure 8% increase vs. 10% decrease and heart rate 8.5% increase vs. 5.4% decrease (p<0.05).This study shows that intravenous administration of midazolam 5 min prior to induction of general anesthesia, is an effective and safe method for reduction of lOP and can be used easily in intraocular procedures.

In a randomized double blind clinical trial, 100 patients with ASA physical status I and II who underwent lower abdominal or lower extremities surgery under spinal anesthesia, were randomly allocated into two groups. In hypertonic saline (HS) group, 1.6 ml/Kg of hypertonic saline and in normal saline (NS) group 13 ml/Kg were infused as fluids for hydration prior to block, for initial fluid administration, thus all the patients received equal amounts of sodium (2mmol/Kg). Heart rate, mean arterial blood pressure, Na, Cl, K and Osmolality were measured at 5 points: 1. Before injection of Pretreatment, 2. After injection of Pretreatment, 3. After spinal anesthesia, 4. After the end of surgery, 5. After recovery from anesthesia (Dorsiflesxion, Plantar flexion of both toes). Demographic parameters, duration, level of spinal anesthesia, heart rate, MAP and injected ephedrin had no statistically significant differences. In both groups there were significant increases in HR and systolic blood pressure (p<0.01). In HS group NA, Cl, and osmolality increased significantly (p<0.01). There were no significant changes in K in both groups. Injected volumes in HS group were significantly less than the NS group (p<0.01).Generally, hemodynamic effects of 7.5% hypertonic saline are similar to normal saline, but patients with compromised cardiovascular system in whom adminstration could not be tolerated or in situations where there is not enough time or a patent line for injection does not exist, hypertonic saline is a better choice than normal saline.

Reducing neuroendocrine responses to surgical trauma during anesthesia has always attracted the attention of anesthesiologists. To achieve the goal, drugs such as beta blocker's, clonidin, opioids and local anestheties are commonly used before painful stimulation has started. Magnesium sulfate is another drug which has been used for this purpose.To evaluate the effects of magnesium sulfate on reducing the neuroendocrine, stress and acute phase responses, in a double blind randomized clinical trial study 50 patients aged 15-45 yr. ASA I, II undergoing laparoscopic surgery under general anaesthasia were studied.Patients were divided in two groups with 25 patients in each group.One group received an infusion of Mgs04 10%, 0.25ml/kg in 20 minutes before induction of anesthesia, while control group, received an infusion of normal saline 0/25 ml/kg in 20 minutes before induction of anesthesia. During surgery the patients received these components at a rate of 0.04 ml/kg/hr via the infusion pumps. Anesthesia was induced with midazolam 0/1 mg/kg fentanyl 3mg/kg and atracurium 0.4 mg/kg as a muscle relaxant. For the maintenance of anesthesia midazolam infusion 1mcg/kg/min. Fentanyl 1 mcg/kg was administered. Then the level of neuroendocrine hormones in serum was measured by using radio-Immunoassay method.We concluded that in contrast to previous studies, no significant reduction in norepinephrine level was noted following administration of magnesium sulfnte given before laryngoscopy.

The major responsibility of the anesthesiologist is to provide adequate respiration for the patient by airway management. For this reason endotracheal intubation is used currently during general anesthesia. Laryngoscope and intubation are powerful noxious stimuli, and this response may have unacceptable cardiovascular effects. Furthermore, deeper levels of anesthesia are required to blunt the response to laryngoscope and intubation that is not suitable for cardiac patients. The other recommended option is use of fiberoptic laryngoscope for tracheal intubation. There are some studies proving hemodynamic stability with fiberoptic laryngoscope.On the other hand there are some studies that don't confirm and reject this hypothesis, because hemodynamic stability is very important specially in cardiac surgery. The present study is a prospective randomized clinical trial analysis on 50 patients undergoing open heart surgery in Shahid Rajaii Heart Center. Inclusion criteria included: ASA physical status 2 and airway class 1 and 2 Cormack patients with mean age 53± 8 years and mean ejection fraction of 47± 3% Patients were divided into two groups (n=25 in each group). In each groups 16 patients were male and 9 of them were female. Selection of the type and the dose of premedication and anesthetic drugs in two groups were the same. The patients were randomly intubated by laryngoscope and fiberoscope. Their heart rate and blood pressure were recorded in 5 stages. The required time for intubation with each of the instruments was recorded by the assistant of the investigator. After collection of data and statistically analysis, we found that although the heart rate and blood pressure changes were important clinically at different stages of anesthesia, there were no significant differences between the two groups.(p<0.05)

Post extubation cough and larynogospasm and also bucking (straining) during emergence from anesthesia can be associated with hemodynamic changes in arterial oxygen saturation (SPa02). Recent studies have revealed that Lidocaine can diffuse across endotracheal cuff membrane and alkalinization and warming of Lidocaine can increase this capability.We decided to determine whether inflating the "SUPA" endotracheal tube's cuff with lidocaine could create a reservoir of local anesthetic, which might diffuse across the cuff membrane to anesthetize the mucosa thus attenuating stimulation during extubation.A total of 120 patients undergoing elective surgery were enrolled in a double blind randomized clinical trial, and occurrence of cough, bucking and laryngospasm noted were in four groups with endotracheal tube cuffs inflated with air, lidocaine 4%, alkalinized lidocaine 4%.Data were analyzed with SPSS windows with chi test and fisher test. There was no differece in study data between air and saline and so between lidocaine 4% and alkalinized lidocaine 4% group. Inflation of cuff with lidocaine was associated with significant decrease in occurrence of coughing and bucking compared to air and saline groups. There was no case of laryngospasm in lidocaine groups. Inflation of the "SUPA" Endotracheal tube cuff with lidocaine can significantly decrease occurence of coughing, straining and probably laryngospasm after extubation.

The action of corticosteroids in prolongation of the analgesic effects of local anesthetics in peripheral nerves is well documented. The objective of this study is to compare the sensory and motor blockade duration of intrathecal lidocaine plus dexamthasone versus plain lidocaine and lidocaine plus epinephrine.Ninety ASA I or II 20 to 45 year old men, undergoing lower abdominal surgery under spinal anesthesia with less than 60 min duration and sensory level lower than T6, in Dr. Shariaty Hospital in winter 1381, were selected for the randomized double blind prospective study. The patients were randomly allocated to lidocaine- dexamethasone (75mg lidocaine plus 8mg dexamethasone intrathecally), lidocaine (75mg lidocaine plus 2ml normal saline intrathecally) and lidocaine- epinephrine (75mg lidocaine plus 0.2mg epinephrine 1/1000 and 2 ml normal saline intrathecally) groups. Four level regression of sensory level was assumed as the end of sensory block. The duration of sensory and motor block, hypotension, bradycardia, nausea and vomiting and neurological complications were assessed.There was no significant difference between age, weight, ASA class initiation time of sensory and motor block and time in attaining the highest level of block. The duration of sensory block was significantly longer in the lidocaine - epinephrine and lidocaine- dexamethasone groups than the lidocaine group (respectively 85.7 and 82.1 min vs. 55.9 min for sensory block and 112.8 and 118.9 min vs. 79.2 for motor block; p<0.001). The incidence of nausea and vomiting and antiemetic administration, hypotension and bradycardia that needed treatment had no significant difference (p>0.05). No neurological deficit or other significant adverse effects were recorded.The addition of intrathecal dexamthasone to lidocaine significantly improves the duration of sensory and motor block following spinal anaesthesia without significant side-effects.

Abdominal complications after cardiac surgery are associated with a high mortality and morbidity rate. Due to the absence of early specific clinical signs, diagnosis is often delayed. Identification of risk factors for prediction of abdominal complications in cardiac surgical patients is the aim of this study.Within 7 months 600 adult patients undergoing open heart surgery with CPB in Tabriz Madani Heart Center were studied prospectively for abdominal complications. To determine predictive factors, all case histories and information of patients were analyzed.Abdominal complications occurred in 25 (4.1%) patients during postoperative ICU stay, one patient undergoing abdominal surgery. Early complications occurred most likely on postoperative days 4-6, consisting of bowel ischemia (ileus), abdominal pain, jaundice, GL bleeding, and pancreatitis. The death rate was 20% (5 patients). The relative risk for abdominal complications after cardiac surgery was highly increased with EF<40% (p<0.05), prolonged mechanical ventilation (p<0.03), emergency surgery (p<0.05), need for IABP or vaspressors during or after surgery (p<0.05), need to re-exploration after surgery (p<0.05), and diabetes mellitus (p<0.03).A number of predictive factors have been described to contribute to the development of abdominal complications after cardiac surgery. Knowledge of these factors may lead to earlier identification of patients at increased risk for more earlier interventions.