Influence of sevoflurane and isoflurane anesthesia on renal function in elderly patients

We examined the influence of sevoflurane and isoflurane anesthesia on renal function in elderly patient who underwent gastrectomy. Plasma inorganic fluoride level was significantly higher in sevoflurane group compared with isoflurane group from 3 hours after the beginning of anesthesia to the 3rd operative day. In contrast, parameters such as urinary beta 2 microglobulin, urinary N-acetyl-beta-D-glucosaminidase, and urinary gamma-GTP activities increased in both groups, but the increase was not significant. Serum BUN and creatinine levels were within normal limits. These results suggest that elderly patients without renal dysfunction appear unlikely to have any significant problem after prolonged sevoflurane anesthesia.     

Perfusion of ischemic myocardium during anesthesia with sevoflurane

BACKGROUND: Sevoflurane produces direct vasodilation of coronary arteries in vitro and decreases coronary vascular resistance in vivo, pharmacologic properties that may contribute to the development of "coronary steal." This investigation examined the effects of sevoflurane on the distribution of regional myocardial perfusion in chronically instrumented dogs with steal-prone coronary artery anatomy. METHODS: Dogs were chronically instrumented for measurement of aortic and left ventricular pressure, diastolic coronary blood flow velocity and subendocardial segment length. After recovery from surgery, dogs underwent repetitive, brief, left anterior descending coronary artery (LAD) occlusions via an implanted hydraulic vascular occluder to enhance collateral development. A progressive left circumflex coronary artery (LCCA) stenosis was also obtained using an ameroid constrictor. After development of LCCA stenosis, the LAD was totally occluded to produce a model of multivessel coronary artery disease. Systemic hemodynamics, regional contractile function and myocardial perfusion measured with radioactive microspheres were assessed in the conscious state and during sevoflurane anesthesia at 1.0 and 1.5 MAC with and without restoration of arterial blood pressure and heart rate to conscious levels. RESULTS: Total LAD occlusion with simultaneous LCCA stenosis increased heart rate, mean arterial pressure, left ventricular systolic and end-diastolic pressures, end-diastolic segment length, and rate-pressure product in conscious dogs. Subsequent administration of sevoflurane caused dose-related decreases in arterial pressure, left ventricular systolic pressure, double product, and peak rate of increase of left ventricular pressure at 50 mmHg. Perfusion of normal myocardium was unchanged during sevoflurane anesthesia. In contrast, sevoflurane caused dose-dependent decreases in blood flow to myocardium supplied by the stenotic LCCA, which returned to control levels after restoration of heart rate and arterial pressure. No reduction in collaterally derived blood flow to the occluded region was produced by 1.0 or 1.5 MAC sevoflurane. No redistribution of blood flow away from the occluded LAD region to normal or stenotic myocardium occurred during sevoflurane anesthesia. In fact, increases in the ratio of blood flow between occluded and normal zones or occluded and stenotic zones were observed in the subepicardium during 1.5 MAC sevoflurane with maintenance of the heart rate and arterial pressure at conscious levels. CONCLUSIONS: The results demonstrate that sevoflurane does not reduce or abnormally redistribute myocardial blood flow derived from coronary collateral vessels in a chronically instrumented canine model of multivessel coronary artery obstruction.     

Recovery parameters after sevoflurane and isoflurane anesthesia

Trauma patients who succumb to their injuries do so by one of several mechanisms discussed in this article. The most common include head injury, exsanguination, sepsis, and multiple organ failure. The article also discusses adverse consequences of hypothermia, including a model for calculating total heat loss.     

Deliberate hypotensive epidural anesthesia for patients with normal and low cardiac output

The use of hypotensive anesthesia is contraindicated in patients with ventricular dysfunction, even though afterload reduction often improves ventricular performance. The purpose of this study was to prospectively assess systemic hemodynamic responses to deliberate hypotension with epidural anesthesia in patients with chronic left ventricular dysfunction. Hemodynamic measurements were performed in 29 patients undergoing total hip arthroplasty under deliberate hypotensive epidural anesthesia using low-dose intravenous epinephrine infusion to maintain mean arterial pressure (MAP) at 50-60 mm Hg. Intraoperative MAP decreased from 100 +/- 16 to 56 +/- 9 mm Hg by 30 min after epidural injection (P < 0.0005). Concurrently, cardiac index (CI) increased from a preanesthetic baseline value of 2.9 +/- 0.5 to 3.3 +/- 0.9 L.min-1.m-2 at 30 min (P < 0.005) after epidural injection and stroke volume index (SVI) increased from 41 +/- 8 to 50 +/- 14 mL.beat-1.m-2 30 min after epidural injection (P < 0.005). Heart rate and central venous and pulmonary artery diastolic pressures were maintained under hypotension with epidural anesthesia in all patients. During deliberate hypotension with epidural anesthesia, patients with a history of congestive heart failure or low preanesthetic CI (< or = 2.5 L.kg-1.m-2) increased their CI and SVI into the normal range. There were no significant perioperative complications in either of these groups. Hypotensive epidural anesthesia can be used successfully in patients with low cardiac output from ventricular dysfunction undergoing total hip arthroplasty.     

Neuromuscular blockade with vecuronium and its reversal with edrophonium during total intravenous anesthesia, neuroleptanalgesia and sevoflurane anesthesia

The neuromuscular blocking effect of vecuronium and its reversibility ith edrophonium were studied under total intravenous anesthesia (TIVA) and compared with those under NLA or sevoflurane anesthesia (SA) in 30 surgical patients. The degree of neuromuscular blockade was evaluated by acceleration of thumb adduction in response to supramaximal stimulation of the ulnar nerve using Accelograph (Biometer). TIVA was induced with droperidol 0.25 mg.kg-1, fentanyl 2-4 micrograms.kg-1 and ketamine 2 mg.kg-1, and maintained with continuous infusion of ketamine 2 mg.kg-1.h-1 with 30-35% O2 in air. NLA was induced with droperidol 0.25 mg.kg-1 and fentanyl 5-10 micrograms.kg-1 and maintained with 66% nitrous oxide in oxygen. SA was induced with thiamylal 5 mg.kg-1 i.v. and maintained with 66% nitrous oxide in oxygen supplemented with sevoflurane (1 MAC). A single bolus intravenous injection of vecuronium 0.1 mg.kg-1 was used for paralysis and reversed with edrophonium 0.75 mg.kg-1 followed by atropine 0.015 mg.kg-1 when the TOF ratio returned to 25%. The times required from administration of vecuronium to completion of maximal block with TIVA, NLA and SA were 196.5 +/- 52.2 sec, 182.5 +/- 47.6 sec and 166.0 +/- 69.0 sec, respectively. There was no significant difference among them. The times from completion of maximal block to 25% recovery of the twitch height in TIVA and NLA were 39.5 +/- 11.0 min and 37.4 +/- 5.8 min without significant difference. Those values, however, were significantly shorter than 64.5 +/- 35.2 min of SA.(ABSTRACT TRUNCATED AT 250 WORDS)     

Dynamic cerebral autoregulation during sevoflurane anesthesia: a comparison with isoflurane

OBJECTIVE: To study the incidence and pattern of epilepsy in patients with periventricular leukomalacia (PVLM) in two specialty clinic settings. BACKGROUND: Motor and cognitive deficit as well as epilepsy are common in patients with PVLM. With modern imaging techniques, PVLM is now easily recognized. METHODS: Epileptic seizures and syndromes as well as motor and cognitive deficits were correlated with MRI findings. Two patient populations were studied: Group A-children with cerebral palsy and PVLM presenting to a center for children with motor disability (n = 19); and Group B-epileptic patients with PVLM presenting to a tertiary epilepsy center (n = 12). A single patient with PVLM and epilepsy who underwent extensive investigations, including intracranial EEG telemetry, is reported. RESULTS: In Group A, 47% of patients had epilepsy (9/19). PVLM was found in 1.27% of patients investigated for epilepsy at a tertiary epilepsy center (12/942). The majority of patients in both groups had multiple seizure types, with complex partial seizures being most common. Of patients with seizures (Groups A and B), 85.7% had intractable epilepsy (18/21). Intracranial EEG in the illustrative case demonstrated a multifocal epileptic process with occipitotemporal predominance. CONCLUSIONS: PVLM was an uncommon underlying cause in patients presenting with epilepsy (Group A); however, patients presenting with motor disability and PVLM (Group B) had a high incidence of seizures. PVLM in epileptic patients is associated with multiple seizure types and medically refractory disease.     

Repeated low-flow sevoflurane anesthesia: effects on hepatic and renal function in beagles

We studied the effects of repeated low-flow sevoflurane anesthesia for 6 hours. Five beagle dogs received 1.3 MAC (3%) sevoflurane anesthesia. Anesthesia of 6 hours was repeated on at the 7th day after the first anesthesia. Compound A gas samples were collected from the inspiratory limb during anesthesia. Concentrations of serum and renal fluoride, hepatic and renal function parameters were measured during and up to 7 days after the first and second anesthesia. The peak concentration of compound A was 23.7 +/- 3.6 ppm at 2 hours and the same level remained during the anesthesia. Plasma fluoride level exceeded 50 mmol.l-1 during anesthesia and rapidly decreased to the preanesthesia level thereafter. Serum GOT increased slightly only on the first postanesthesia day. No significant changes in other blood chemistry studies were observed. The excretion of renal tubular enzymes did not increase during and after anesthesia. Repeated low flow sevoflurane anesthesia in beagles did not affect hepatic and renal function significantly.     

Induction of anesthesia and tracheal intubation with sevoflurane in adults

BACKGROUND: The speed, quality, and cost of mask induction of anesthesia and laryngeal mask airway insertion or tracheal intubation were studied in young non-premedicated volunteers given high inspired concentrations of sevoflurane (6 to 7%). METHODS: Twenty healthy persons who were 19 to 32 years old participated three times, received 6 l/min fresh gas flow, and were randomized to receive 6 to 7% sevoflurane in 66% nitrous oxide/28% oxygen by face mask until tracheal intubation (treatment 1) or until laryngeal mask airway insertion (treatment 3), or 6 to 7% sevoflurane without nitrous oxide to tracheal intubation (treatment 2). Participants exhaled to residual volume and took three vital capacity breaths of the gas mixture; thereafter ventilation was manually assisted. The time of exposure to the inhaled gas was varied for consecutive participants. It was either increased or decreased by 30-sec increments based on the failure or success of the preceding volunteer's response to laryngoscopy and intubation after a preselected exposure time. Failure was defined as poor jaw relaxation, coughing or bucking, or inadequate vocal cord relaxation. RESULTS: Loss of the lid-lash reflex in unpremedicated young volunteers was achieved in 1 min and did not differ among groups. Average time (and 95% confidence interval) for acceptable conditions for LMA insertion was achieved in 1.7 (0.7 to 2.7) min, and all participants had an immediate return of spontaneous ventilation. The time for acceptable tracheal intubating conditions after manual hyperventilation by mask was 4.7 (3.7 to 5.7) min and 6.4 (5.1 to 7.7) min in treatments 1 and 2, respectively. There were no cases of increased secretions or laryngospasm. The incidence of breath holding and expiratory stridor ("crowing") was 7.5% and 25%, respectively, during treatment 1 and 15% and 40%, respectively, during treatment 2. CONCLUSIONS: The induction of anesthesia to loss of lid reflex in young non-premedicated adults approaches the speed of intravenous induction techniques. No untoward airway responses were noted during mask induction of anesthesia with a three-breath technique. In response to intubation, no adverse airway responses, including jaw tightness, laryngospasm, and excessive coughing or bucking, occurred in participants whose duration of mask administration of sevoflurane met the appropriate times (as determined in this study).     

Time-dependent changes in heart rate and pupil size during desflurane or sevoflurane anesthesia

To better characterize alterations in autonomic function associated with prolonged anesthesia, we tested the hypothesis that the time-dependent effects of sevoflurane and desflurane differ. We studied seven male volunteers, each anesthetized for 8 h with 1.25 minimum alveolar anesthetic concentration desflurane on one study day and with 8 h sevoflurane on another. These volunteers did not undergo surgery and were minimally stimulated during the study. Measurements included blood pressure, heart rate, pupillary size and light reactivity, concentrations of serum catecholamines, and carbon dioxide production. Over time, heart rate and pupil size increased significantly. During 6 of the 14 anesthetics (45%), heart rate at some point exceeded 95 bpm; similarly, pupil size at some time exceeded 5 mm during 8 anesthetics (57%). In contrast, plasma catecholamine concentrations and carbon dioxide production remained unchanged, and blood pressure remained nearly constant. There are thus substantial time-dependent changes in autonomic functions during prolonged anesthesia, even in unstimulated, nonsurgical volunteers, but we could not detect a difference in these changes during desflurane compared with sevoflurane anesthesia. Implications: Pupil size and heart rate changes are used to guide the delivery of anesthesia. In volunteers, pupil size and heart rate increased with increasing duration of constant desflurane or sevoflurane anesthesia. Thus, anesthetic duration alters heart rate and pupil size independent of surgery and changes in anesthetic delivery.     

Neuromuscular effects of rocuronium during sevoflurane, isoflurane, and intravenous anesthesia

The potency and time course of action of rocuronium were studied in patients anesthetized with 66% nitrous oxide in oxygen and 1.5 minimum alveolar anesthetic concentration of sevoflurane or isoflurane, or a propofol infusion. Potency was estimated by using the single-bolus technique. Neuromuscular block was measured by stimulation of the ulnar nerve and by recording the force of contraction of the adductor pollicis muscle. The mean (95% confidence limits) of the 50% and 95% effective doses were estimated tobe 142 (129-157) and 265 (233-301) microg/ kg, 165 (146-187) and 324 (265-396) microg/kg, and 183 (163-207) and 398 (316-502) microg/kg during sevoflurane, isoflurane, and propofol anesthesia, respectively (P < 0.05 for sevoflurane versus propofol). The mean +/- SD times to onset of maximal block after rocuronium 0.6 mg/kg were 0.96 +/- 0.16, 0.90 +/- 0.16, and 1.02 +/- 0.15 min during sevoflurane, isoflurane, and propofol anesthesia, respectively. The respective times to recovery of the first response in the train-of-four (TOF) stimulation (T1) to 25% and 90% were 45 +/- 13.1 and 83 +/- 29.3 min, 35 +/- 6.1 and 56 +/- 15.9 min, and 35 +/- 9.2 and 55 +/- 19.4 min. The times to recovery of the TOF ratio to 0.8 were 103 +/- 30.7, 69 +/- 20.4, and 62 +/- 21.1 min, and the 25%-75% recovery indices were 26 +/- 11.7, 12 +/- 5.0, and 14 +/- 6.9 min, respectively. There were no differences among groups in the times for onset of action or to recovery of T1 to 25%. However, the times for recovery of T1 to 90%, TOF ratio to 0.8, and recovery index in the sevoflurane group were all significantly longer compared with the other two groups (P < 0.05, < 0.01, and < 0.01, respectively). We conclude that the effects of rocuronium, especially duration of action, are significantly enhanced during sevoflurane compared with isoflurane and propofol anesthesia. IMPLICATIONS: In routine clinical use, the effects of rocuronium are enhanced by sevoflurane, in comparison with isoflurane and propofol anesthesia, and the recovery is slower. Particular attention should be paid to monitoring of neuromuscular block during sevoflurane anesthesia.     

Antiemetic activity of propofol after sevoflurane and desflurane anesthesia for outpatient laparoscopic cholecystectomy

BACKGROUND: Controversy exists regarding the effectiveness of propofol to prevent postoperative nausea and vomiting. This prospective, randomized, single-blinded study was designed to evaluate the antiemetic effectiveness of 0.5 mg/kg propofol when administered intravenously after sevoflurane- compared with desflurane-based anesthesia. METHODS: Two hundred fifty female outpatients undergoing laparoscopic cholecystectomy were assigned randomly to one of four treatment groups. All patients were induced with intravenous doses of 2 mg midazolam, 2 microg/kg fentanyl, and 2 mg/kg propofol and maintained with either 1-4% sevoflurane (groups 1 and 2) or 2-8% desflurane (groups 3 and 4) in combination with 65% nitrous oxide in oxygen. At skin closure, patients in groups 1 and 3 were administered 5 ml intravenous saline, and patients in groups 2 and 4 were administered 0.5 mg/kg propofol intravenously. Recovery times were recorded from discontinuation of anesthesia to awakening, orientation, and readiness to be released home. Postoperative nausea and vomiting and requests for antiemetic rescue medication were evaluated during the first 24 h after surgery. RESULTS: Propofol, in an intravenous dose of 0.5 mg/kg, administered at the end of a sevoflurane-nitrous oxide or desflurane-nitrous oxide anesthetic prolonged the times to awakening and orientation by 40-80% and 25-30%, respectively. In group 2 (compared with groups 1, 3, and 4), the incidences of emesis (22% compared with 47%, 53%, and 47%) and requests for antiemetic rescue medication (19% compared with 42%, 50%, and 47%) within the first 6 h after surgery were significantly lower, and the time to home-readiness was significantly shorter in duration (216 +/- 50 min vs. 249 +/- 49 min, 260 +/- 88 min, and 254 +/- 72 min, respectively). CONCLUSIONS: A subhypnotic intravenous dose of propofol (0.5 mg/kg) administered at the end of outpatient laparoscopic cholecystectomy procedures was more effective in preventing postoperative nausea and vomiting after a sevoflurane-based (compared with a desflurane-based) anesthetic.     

Recovery from sevoflurane anesthesia: a comparison to isoflurane and propofol anesthesia

BACKGROUND: Sevoflurane has a lower blood:gas partition coefficient than isoflurane, which may cause a more rapid recovery from anesthesia; it also might cause faster emergence times than for propofol-based anesthesia. We evaluated a database that included recovery endpoints from controlled, randomized, prospective studies sponsored by Abbott Laboratories that compared sevoflurane to isoflurane or propofol when extubation was planned immediately after completion of elective surgery in adult patients. METHODS: Sevoflurane was compared to isoflurane in eight studies (N=2,008) and to propofol in three studies (N=436). Analysis of variance was applied using least squares method mean values to calculate the pooled mean difference in recovery endpoints between primary anesthetics. The effects of patient age and case duration also were determined. RESULTS: Sevoflurane resulted in statistically significant shorter times to emergence (-3.3 min), response to command (-3.1 min), orientation (-4.0 min) and first analgesic (-8.9 min) but not time to eligibility for discharge (-1.7 min) compared to isoflurane (mean difference). Times to recovery endpoints increased with increasing case duration with isoflurane but not with sevoflurane (patients receiving isoflurane took 4-5 min more to emerge and respond to commands and 8.6 min more to achieve orientation during cases longer than 3 hr in duration than those receiving sevoflurane). Patients older than 65 yr had longer times to orientation, but within any age group, orientation was always faster after sevoflurane. There were no differences in recovery times between sevoflurane and propofol. CONCLUSIONS: Recovery from sevoflurane was 3-4 min faster than with isoflurane in all age groups, and the difference was magnified in longer-duration surgical cases (> 3 hr).     

Continuous thoracic epidural blockade in combination with general anesthesia with nitrous oxide, oxygen, and sevoflurane in two patients with myasthenia gravis

Continuous thoracic epidural anesthesia (T4/5) using 4-5 ml.h-1 of 1.5% lidocaine with 1:200,000 epinephrine and inhaled anesthesia using nitrous oxide, oxygen and sevoflurane were performed in two patients, (40 and 22 yr-old females) with myasthenia gravis. This combined anesthetic technique provided muscle relaxation for endotracheal intubation and optimal operating conditions, including muscle relaxation and stability of hemodynamics during transsternal thymectomy. Further, continuous epidural anesthesia using 4 ml.h-1 of 0.25% bupivacaine provided postoperative pain relief without other analgesics and stable postoperative respiratory conditions. In conclusion, we confirm the benefits of this technique which provides not only safe and stable conditions during the surgery, but also an improved comfort for patients in the postoperative period following transsternal thymectomy for myasthenia gravis.     

Renal function and oxygen consumption during bacteraemia and endotoxaemia in rats

BACKGROUND: The hypothesis that renal failure during septic shock may occur as a result of hypoxia-related cell dysfunction was investigated in two rat models of distributive shock. METHODS: Pentobarbitone-anaesthetized rats received either a bolus (1 ml) of living Escherichia coli bacteria (hospital-acquired strain, 1 x 10(9) CFU/ml; BA-group, n = 7), or a 1-h infusion of endotoxin (E. coli O127.B8: 8 mg/kg; ET-group, n = 7), or saline to serve as time matched controls (C-group, n = 7). RESULTS: Urine flow in the BA- and ET-group reached a nadir at 1 h, but thereafter increased and reached values higher than control at 3 h. At this time point, renal oxygen delivery had decreased, in the BA-group mainly due to a fall in arterial oxygen content and in the ET-group to a fall in renal plasma flow (clearance of 131I-hippurate). However, renal oxygen extraction had significantly increased, by 31% in the BA and by 59% in the ET group, while renal oxygen consumption remained the same. Net tubular sodium reabsorption had decreased by 55% in the BA and by 25% in the ET group, due to a fall in glomerular filtration rate (clearance of creatinine). Hence, an excess oxygen consumption was found which was caused neither by an increased renal glucose release nor by the presence of an increased number of leukocytes stuck in the glomeruli. Renal tubular cells showed normal morphology. An indication that proximal tubular function in the BA and ET group remained largely intact were normal ATP levels, absence of urinary glucose, and a normal fractional excretion of sodium. However, since urine flow had increased in shocked rats at 3 h, water appeared selectively lost. CONCLUSIONS: Our data indicate that in rat models of septic shock renal failure is not caused by cortical hypoxia or a shortage of cellular energy supply.     

Environmental monitoring during gaseous induction with sevoflurane

Recent research has shown that gaseous induction in adults with sevoflurane is an acceptable technique. This study was undertaken to assess if gaseous induction using sevoflurane carried in both oxygen alone, and in nitrous oxide and oxygen combined, would provide acceptable pollution levels. As an occupational exposure standard has not been set for sevoflurane, we used the target level of 20 ppm set by the manufacturer. Environmental monitoring was carried out in the anaesthetic room during eight lists where consecutive triple vital capacity sevoflurane inductions were performed. Time-weighted averages for both gases over the duration of the lists were well below the occupational exposure standards (mean 1.1 (range 0.6-1.7) for sevoflurane and 17.3 (12-23) for nitrous oxide). There were high peak concentrations during the induction process (8.3 (4.1-17) for sevoflurane and 172.4 (65-310) for nitrous oxide) although these decreased to low concentrations between anaesthetic inductions. Personal sampling was carried out from the anaesthetist's breathing zone and concentrations were also low (1.2 (0.8-2.1) for sevoflurane and 45.9 (10.1-261.6) for nitrous oxide.     

Renal function after nephrectomy for Wilms'' tumor]

In times of reduced monetary resources of the current German health system, it is more and more difficult for the German physicians to comply with the high medicinal care standard and to practice economically. Nevertheless, the economical reasons cannot deny the high medical quality standards. Regarding the principle of the unity of jurisdiction, the validity of the social welfare law, that a performance has to be "just sufficient and suitable", must concur with the demand of liability law of "indication of the medical service". The economical duties reach their limit when they increase the risk for the patient. On the other hand, the economy interests have to be regarded by the "principle of the allowed risk". Therefore, it should be considered that in every single case the severity and probability of the risk has to be weighed against the cost aspect.     

Comparative study of recovery times and psychomotor function after anesthesia with desflurane or isoflurane

At variance with the earlier belief that mitochondrial genomes are represented by circular DNA molecules, a large number of organisms have been found to carry linear mitochondrial DNA. Studies of linear mitochondrial genomes might provide a novel view on the evolutionary history of organelle genomes and contribute to delineating mechanisms of maintenance and functioning of telomeres. Because linear mitochondrial DNA is present in a number of human pathogens, its replication mechanisms might become a target for drugs that would not interfere with replication of human circular mitochondrial DNA.