Journal of anesthesia
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Journal of anesthesia · Mar 1997
Effects of bupivacaine and lidocaine on cardiac function in awake and pentobarbital-anesthetized rats.
Using an implanted Doppler crystal, we evaluated emodynamic changes induced by subconvulsive doses of bupivacaine and lidocaine in awake and pentobarbitalanesthetized rats. Low doses of lidocaine (2.0 mg·kg-1) and bupivacaine (0.5 mg·kg-1) changed hemodynamics minimally. ⋯ Under pentobarbital anesthesia, a high dose of lidocaine reduced mean arterial pressure significantly shortly after the injection, but bupivacaine did not. Thus, it is unlikely that bupivacaine has more potent cardiotoxicity than lidocaine in subconvulsive doses.
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CO2 absorbents acting on sevoflurane produce compound A [CF2=C(CF3)OCH2F]. Rats breathing 25-50 ppm of compound A for 3-12 h demonstrate corticomedullary renal injury. Several halogenated alkenes also produce a well described corticomedullary lesion by conversion of glutathione conjugates of these alkenes to cysteine s-conjugates and subsequent metabolism by renal cysteine conjugate β-lyase to nephrotoxic halothionoacetyl halides. ⋯ In rats exposed to 800 ppm compound A, pretreatment with AOAA increased necrosis from 63.8±30.1% to 81.2±27.7% (P<0.1). Unlike many other halogenated alkenes, compound A does not appear to produce renal injury by conversion of a cysteine S-conjugate to a toxic thiol, nor does injury require metabolism mediaited by cytochrome P-450. Injury may result from direct toxicity of compound A or by an undetermined metabolic pathway.
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Journal of anesthesia · Mar 1997
Effects of fentanyl on cardiovascular response during rapid sequence induction in hypertensive patients.
This study was carried out to evaluate the effects of fentanyl on cardiovascular and catecholamine responses during rapid sequence induction (RSI) in hypertensive patients. Twenty-eight patients were allocated into one of 3 groups: group 1 (n=7) consisted of normotensive patients receiving no fentanyl, group 2 (n=10) consisted of normotensive patients receiving fentanyl, and group 3 (n=11) consisted of hypertensive patients receiving fentanyl. RSI was performed with thiamylal (4mg·kg-1) and succinylcholine (2mg·kg-1) for all groups. ⋯ Group 2 showed a significant increase in HR at T3 but not in SAP or catecholamines. Group 3 showed no increase in SAP, HR, or catecholamines throughout the time course. The results suggest that fentanyl is useful to suppress sympathoadrenal and cardiovascular responses to RSI in hypertensive patients as well as normotensive patients.
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Journal of anesthesia · Mar 1997
Parasympathetic nervous activity after administration of atropine and neostigmine using heart rate spectral analysis.
Recently, heart rate spectral analysis has become recognized as a powerful tool for quantitatively evaluating autonomic nervous system activity. The purpose of this study was to analyze parasympathetic nervous activity by heart rate spectral analysis after administration of atropine and neostigmine for reversal of residual neuromuscular blockade. For our study, 36 female patients (26-37 years of age), ASA physical status (PS) I, who were scheduled for laparoscopic examination, were randomly allocated to one of the following four groups: In group A (1∶1), 9 patients received 1.0mg atropine followed 4 min later by 1.0 mg neostigmine. ⋯ In group A, the HF-p increased after neostigmine but did not differ from the control. The difference between groups D and B was not statistically significant. From the results of this study, we concluded that the muscarinic effect of neostigmine could not be sufficiently blocked by atropine at 1/2 dosages of neostigmine, but could be sufficiently blocked by atropine at equivalent dosages of neostigmine, under light isoflurane anesthesia.