Effect of repeated exposure to isoflurane on liver of rats subjected to hypoxia and enzyme induction Histopathological and histochemical study

Forty eight white rats divided into 8 equal groups were used. Group 1 was exposed to 100% O2. Group 2 exposed to isoflurane 1% in O2. Group 3 exposed to hypoxic mixture [10% O2 in N2]. Group 4 exposed to isoflurane 1% in the hypoxic mixture. The rats of the other four groups were pretreated with 0.1% phenobarbitone in milk 5 days before and throughout the whole experiment. Exposure was done in special exposure box for 30 minutes every other day for 12 exposures. Liver sections stained with Hx and E and PAS to detect histopathological changes and histochemically to detect liver enzyme activity. Mild histopathological and histochemical changes were detected in all groups when compared with the control ones, indicating absence of hepatic insult following exposure to isoflurane alone or combined with hypoxia and enzyme induction

Effect of repeated exposure to isoflurane on the liver of rats fed on low protein diet Histopathological and histochemical study

Forty eight white rats divided into 8 equal groups were used. The animals of the first four groups were fed on a standard diet composed of milk and bread ad libitum. While the rats of the other four groups were kept on a special diet composed of bread in water, i.e. relatively protein poor diet ad libitum. Group I was exposed to O2 100%. Group II was exposed to 1% isoflurane in O2. Group III was exposed to hypoxic mixture [10% O2 in N2]. Group IV was exposed to 1% isoflurane carried by the hypoxic mixture. The animals of the last four groups kept on low protein diet were exposed in a similar sequence like the first 4 groups. Exposure was 30 minutes every other day for 12 exposures. No histopathological changes detected in rats exposed to O2 100%, fed on either types of food. While mild histopathological changes in the form of focal fatty change or vacular degeneration in other groups. Depressed activity of acid phosphatase, lactic dehydrogenase and succinic dehydrogenase enzymes were observed in groups maintained on low protein diet which was the probable cause for this depressed activity

Effect of repeated exposure to isoflurane on the liver of stressed rats Histopathological and histochemical study

Twenty four male white rats divided into 4 equal groups were used in this study. Group I was kept as a control. Group II was exposed to 1% isoflurane in oxygen 30 minutes every other day for 12 exposures. The rats of groups III and IV were subjected for 20 minutes of stress by hitting on their cages in non rhythmic way. Group III was exposed to 1% isoflurane in O2 for 12 exposures like group II. Liver sections stained with Hx and E and PAS showed no histopathological changes in groups I and III, focal fatty change in group II and vacular degeneration with ballooning of the hepatocytes in group IV. Mild depression of acid phosphatase, lactic and succinic dehydrogenase enzyme activity in stressed rats in groups III and V. These changes were mild and signify no pathological importance

Respiratory function profile in response to some narcotic analgesics

Thirty ASAI adult volunteers classified into 3 equal groups were chosen. Their mean age and body weight were 27 years and 65.4 kg, respectively. Pentazocine [0.3 mg/kg], butorphanol [0.03 mg/kg] and morphine [0.16 mg/kg] were injected i.m. to the members of groups 1, 2 and 3, respectively. In all members of the three groups recording of respiratory rate and d battery of respiratory function tests were done before, half an hour and one hour after the injection of the drugs. These tests include VC, FVC, FEVI, FEER [0.2-1.2] and FMEFR [25-75%]. No significant changes in the studied parameters were observed with pentazocine, while significant decrease in respiratory rate was recorded half an hour after morphine and one hour after both butorphanol and morphine administration. The two drugs had no significant effect on other respiratory function tests. There was significant reduction in respiratory rate in both butorphanol and morphine groups half an hour and one hour after the injection on comparison with pentazocine group

End tidal carbon dioxide [PETCO2] as a monitor and guide for neuromuscular recovery

This study was planned to evaluate the validity of monitoring PETC02 in assessing the degree of block following the use of nondepolarizing muscle relaxant and a guide for recovery of myoneural function. Twenty patients were included in this study. General anesthesia was induced with thiopentone sod. and maintained with gas-oxygen, halothan and relaxant [pancuronium]. The patients were classified into 2 groups according to the mode of analgesia. The patients were mechanically ventilated except for periods of 5 minutes where spontaneously ventilation through a T-piece at different grades of block. During these periods PETCO2, TV and RR were recorded. Significant elevation of PETCO2 were recorded at high degree of block associated with significant decrease in TV and increase in RR. With recovery of myoneural block PETCO2 decreased to reach near basal level and TV increased toward the starting volume with RR remained significantly high meaning that there discrenible relationship between the degree of peripheral neuromuscular block and respiratory performance. Monitoring of PETCO2 during block by relaxants can be used as a guide to monitor the degree of block and recovery of myoneural function

Effect of priming dose of thiopentone sodium on the total dose requirement

This study was designed to evaluate the effect of priming dose of thiopentone sodium on the total dose requirement when thiopentone is used as a sole anesthetic for D and C operation. 50 adult ASAI female patients undergoing D and C operation were chosen and divided to 5 equal groups, 10 patients each. The first group was kept as a control where the drug was given in a bolus dose of 5 mg/kg followed by incremental dose as required. The second and third groups were given 1 and 2 mg/kg, respectively, 2 minutes before administration of the anesthetizing dose. The same was repeated with forth and fifth groups except the priming dose, which was given 4 minutes before the anesthetizing dose. Recovery was assessed by return of eyelid and eyelash reflect. The total required dose was calculated/kg for each patient. Significant reduction in the total required dose was recorded in all patients received priming dose in comparison with the control bolus group and the best reduction was in the second group who received 1 mg as priming dose 2 minutes before the anesthetizing dose. No significant difference in the duration of action of the total dose given to the control and studied groups

Impact of preoperative assessment on timing of the operation and perioperative outcome

This retrospective study was conducted on 101 patients diagnosed as bladder cancer and subjected to radical cystectomy operation. Estimation of incidence of medical problem preoperatively, correlation between clinical and laboratory data and the impact of these on the timing of the operation and perioperative outcome were studied. Hepatic abnormalities were the most common medical problem [28.7%] followed by cardiovascular [22.8%], anemia [13.9%] and respiratory diseases [11.9%]. Hepatic patients were diagnosed through abnormal liver function tests, the operation was postponed in 2 patients only. One patient developed mild elevation in serum bilirubin postoperatively. Arrhythmias were the most common abnormality in patients with cardiovascular dysfunction [56.5%] followed by hypertension [17.4%] and ischemic heart diseases [8.7%]. 34.8% of these patients were postponed and the postoperative complications were ventricular ectopics [13.4%] and hypertension [4.34%]. 35.7% of the anemic patients were postponed for correction of anemia. 7 out of 12 patients had increase bronchovascular marking on X-ray without clinical abnormality with no postoperative complications. While for the 5 patients, who showed clinical abnormalities, the operation was postponed for treatment and the postoperative chest complications developed in 8.3% of them

Respiratory mechanics during laparoscopic nephrectomy

37 adult ASA I or II patients divided into 3 groups and subjected to laparoscopic nephrectomy were assigned for this study. Oral diazepam was used for premedication. Induction with thiopentone sodium, suxamethonium sequence and maintenance of anesthesia were achieved differently in each group. In group 1, it was N2O: O2 halothane 0.5- 1%, while in group 2 N2O: O2 morphine were used. In group 3, lumber epidural analgesia [using bupivacain 0.8 mg/kg + 2 mg morphine] preceded general anesthesia, N2O: O2 was used for maintenance. Pancuronium was the non-depolarizing muscle relaxant used. Intraperitoneal CO2 insufflation was performed in lateral decubitus position. Respiratory mechanics including total chest compliance, peak inspiratory pressure, respiratory and expiratory resistance were recorded for every patient, before and after maximal CO2 insufflation and after deflation of CO2. Significant decrease in total chest compliance and significant increase in both peak inspiratory pressure and expiratory resistance were recorded with maximal CO2 insufflation. This was recorded in all groups studied irrespective to the mode of balanced anesthesia used. CO2 pneumoperitoneum during laparoscopic nephrectomy adds to the ventilatory impairment induced by anesthesia and lateral decubitus position which mandate careful adjustment of patient ventilation during the procedure

Gastric acidity during laparoscopy a preliminary study

Twelve adult ASA I or II patients subjected to laparoscopic nephrectomy were used in this study. Oral diazepam was given 2 hours before induction of anesthesia. Thiopentone sodium, suxamethonium sequence, was used for induction and N2O: O2 [65: 35] halothane 0.5-1% and pancuronium [0.1 mg/kg] were used for maintenance of anesthesia and controlled ventilation. Intraperitoneal insufflation of CO2 was done after turning the patient to lateral decubitus position. Nasogastric tube was introduced before CO2 insufflation to evacuate the stomach and to get the first sample of gastric secretion. The second sample was withdrawn just after deflation of CO2. Similarly two arterial blood samples were withdrawn. Gastric acidity was determined in the two samples and was expressed as mmol/L. Also, arterial pH and level of arterial CO2 pressure [PaCO2] in the two blood samples were also measured. The duration of CO2 insufflation was recorded for each patient. Significant increase in gastric acidity was observed at the end of CO2 insufflation and similarly was PaCO2, while arterial pH showed significant decrease. Significant positive correlation existed between the level of gastric acidity and PaCO2 after deflation of CO2, which was not the case with either arterial pH or duration of CO2 insufflation. The increased gastric acidity during laparoscopic procedures using CO2 pneumoperitoneum puts those patients more at risk

Arterial gasometry during laparoscopic nephrectomy

Thirty seven adult patients undergoing laparoscopic nephrectomy were chosen for this study. They were divided into three groups. Premedication was with oral diazepam. Thiopentone-suxamethonium were used for induction of anesthesia and endotracheal intubation. Maintenance of anesthesia was by N2O: O2 halothan 0.5-1% in group 1 and N2O: O2 morphine in group 2. In group 3 epidural analgesia using bupivacaine and morphine preceded general anesthesia which was maintained by N2O: O2. Muscle relaxation was achieved by pancuronium. Intraperitoneal insufflation of CO2 was performed in lateral decubitus position. Arterial blood samples were collected during the operation for determination of PaO2, PaCO2, SO2, pH and PAO2. Maintenance of significantly high PaO2, SO2, PAO2 and P[A-a]O2 over the basal level was achieved after increasing inspired O2 concentration from 21% to 35%. Significant increase in PaCO2 and P50 and significant decrease in pH extending to the postoperative period, were observed due to storage of excess CO2 in body tissue during the prolonged procedure. Arterial blood gas monitoring may be required to detect developing hypercarbia and acidosis during laparoscopic nephrectomy