Effect of suxamethonium vs rocuronium on onset of oxygen desaturation during apnoea following rapid sequence induction

This study investigates the effect of suxamethonium vs rocuronium on the onset of haemoglobin desaturation during apnoea, following rapid sequence induction of anaesthesia. Sixty patients were randomly allocated to one of three groups. Anaesthesia was induced with lidocaine 1.5 mg.kg^?1, fentanyl 2 μg.kg^?1 and propofol 2 mg.kg^?1, followed by either rocuronium 1 mg.kg^?1 (Group R) or suxamethonium 1.5 mg.kg^?1 (Group S). The third group received propofol 2 mg.kg^?1 and suxamethonium 1.5 mg.kg^?1 only (Group SO). The median (IQR [range]) time to reach S_pO ₂ of 95% was significantly shorter in Group S (358 (311–373 [215–430]) s) than in Group R (378 (370–393 [366–420]) s; p = 0.003), and shorter in Group SO (242 (225–258 [189–370]) s) than in both Group R (p < 0.001) and Group S (p < 0.001). When suxamethonium is administered for rapid sequence induction of anaesthesia, a faster onset of oxygen desaturation is observed during the subsequent apnoea compared with rocuronium. However, time to desaturation is prolonged whenever lidocaine and fentanyl precede suxamethonium.     

Effect of alpha-stat vs. pH-stat strategies on cerebral oximetry during moderate hypothermic cardiopulmonary bypass

BACKGROUND AND OBJECTIVES: This study was undertaken to compare the effect of alpha-stat vs. pH-stat strategies for acid-base management on regional cerebral oxygen saturation (RsO2) in patients undergoing moderate hypothermic haemodilution cardiopulmonary bypass (CPB). METHODS: In 14 adult patients undergoing elective coronary artery bypass grafting, an awake RsO2 baseline value was monitored using a cerebral oximeter (INVOS 5100). Cerebral oximetry was then monitored continuously following anaesthesia and during the whole period of CPB. Mean +/- SD of RsO2, CO2, mean arterial pressure and haematocrit were determined before bypass and during the moderate hypothermic phase of the CPB using the alpha-stat followed by pH-stat strategies of acid-base management. Alpha-stat was then maintained throughout the whole period of CPB. RESULTS: The mean baseline RsO2 in the awake patient breathing room air was 59.6 +/- 5.3%. Following anaesthesia and ventilation with 100% oxygen, RsO2 increased up to 75.9 +/- 6.7%. Going on bypass, RsO2 significantly decreased from a pre-bypass value of 75.9 +/- 6.7% to 62.9 +/- 6.3% during the initial phase of alpha-stat strategy. Shifting to pH-stat strategy resulted in a significant increase of RsO2 from 62.9 +/- 6.3% to 72.1 +/- 6.6%. Resuming the alpha-stat strategy resulted in a significant decrease of RsO2 to 62.9 +/- 7.8% which was similar to the RsO2 value during the initial phase of alpha-stat. CONCLUSION: During moderate hypothermic haemodilutional CPB, the RsO2 was significantly higher during the pH-stat than during the alpha-stat strategy. However, the RsO2 during pH-stat management was significantly higher than the baseline RsO2 value in the awake patient breathing room air, denoting luxury cerebral perfusion. In contrast, the RsO2 during alpha-stat was only slightly higher than the baseline RsO2, suggesting that the alpha-stat strategy avoids luxury perfusion, but can maintain adequate cerebral oxygen supply-demand balance during moderate hypothermic haemodilutional CPB.     

Supplementation of pre-oxygenation in morbidly obese patients using nasopharyngeal oxygen insufflation

During apnoea following induction of anaesthesia, morbidly obese patients may suffer a rapid decrease in oxygen saturation. This study compares pre-oxygenation alone with pre-oxygenation followed by nasopharyngeal oxygen insufflation on the onset of desaturation occurring during the subsequent apnoea. A randomised controlled trial was performed in 34 morbidly obese patients undergoing gastric bypass or gastric band surgery. Seventeen patients received nasopharyngeal oxygen supplementation following pre-oxygenation (Study group, body mass index = 41.8 (6.9) kg.m(-2)), and the other 17 patients received pre-oxygenation alone (Control group, body mass index = 42.7 (5.4) kg.m(-2)). Time from the onset of apnoea until S(p)o(2) fell to 95% was compared between the two groups with a cut-off of 4 min. In the control group, the S(p)o(2) fell from 100% to 95% during the subsequent apnoea in 145 (27) s, with a significantly negative correlation (r(2) = 0.66, p < 0.05) between the time to desaturation to 95% and the body mass index. In the study group, the S(p)o(2) was maintained in 16 of 17 patients at 100% for 4 min when apnoea was terminated. In conclusion, nasopharyngeal oxygen insufflation following pre-oxygenation in morbidly obese patients delays the onset of oxyhaemoglobin desaturation during the subsequent apnoea.     

Do desipramine [10,11-dihydro-5-[3-(methylamino) propyl]-5H-dibenz[b,f]azepine monohydrochloride] and fluoxetine [N-methyl-3-phenyl-3-[4-(trifluoromethyl)phenoxy]-propan-1-amine] ameliorate the extent of colonic damage induced by acetic acid in rats?

The present study was designed to compare the anti-inflammatory and antioxidant effects of two antidepressant drugs, desipramine [10,11-dihydro-5-[3-(methylamino) propyl]-5H-dibenz-[b,f]azepine monohydrochloride] and fluoxetine [N-methyl-3-phenyl-3-[4-(trifluoromethyl)phenoxy]-propan-1-amine], administered with variable doses, on experimentally induced colitis in rats. Two doses for each drug (10 and 20 mg/kg/day i.p.) were injected in 48 adult male albino rats for 2 weeks after induction of colitis by intracolonic administration of 2 ml of 3% acetic acid. Several parameters, including macroscopic (ulcer score index) and biochemical such as myeloperoxidase (MPO), reduced glutathione (GSH), tumor necrosis factor (TNF)-alpha, and interleukin (IL)-1beta, were measured using standard assay procedures. The study demonstrates that both desipramine and fluoxetine significantly attenuated the extent and the severity of the macroscopic signs of cell damage. Both drugs significantly reduced tissue MPO activity in a dose-dependent manner. Both desipramine and fluoxetine, at either dose, significantly increased GSH in colonic tissue. Desipramine and fluoxetine, at either dose, significantly reduced TNF-alpha and IL-beta. Desipramine at the dose of 20 mg/kg produced more decrease in the level of TNF-alpha compared with the effect of the smaller dose, but fluoxetine at 10 mg/kg diminished more in the level of IL-1beta compared with the effect of the larger dose. The present data indicate that both desipramine and fluoxetine have anti-inflammatory and antioxidants effects in experimentally induced colitis in rats, opening the avenue to their possible protective role in patients with inflammatory bowel disease.