Desflurane Confers Neurologic Protection for Deep Hypothermic Circulatory Arrest in Newborn Pigs

Background: Cardiopulmonary bypass (CPB) and deep hypothermic circulatory arrest (DHCA), as used for infant heart surgery, carry a risk of ischemic neurologic injury. Volatile anesthetics have neuroprotective properties against both global and focal ischemia at normothermia. The authors examined the hemodynamic and neuroprotective effects of desflurane in a piglet CPB-DHCA model.

Methods: Twenty piglets aged 5-10 days received a desflurane- (6-9% expired) or fentanyl-based anesthetic before and during CPB (before and after DHCA). DHCA lasted 90 min at 19[degrees]C brain. Cardiovascular variables (heart rate, arterial pressure, blood gases, glucose, brain temperature) were monitored. On postoperative day 2, neurologic and histologic outcomes were determined.

Results: Cardiovascular variables before, during, and after CPB were physiologically similar between groups. The desflurane group had better neurologic performance (P = 0.023) and greater postoperative weight gain (P = 0.04) than the fentanyl group. In neocortex, the desflurane group had less tissue damage (P = 0.0015) and fewer dead neurons (P = 0.0015) than the fentanyl group. Hippocampal tissue damage was less in the desflurane group (P = 0.05), but overall, neuronal cell counts in the CA1 sector of the right hippocampus were similar to those in the fentanyl group.     

Desflurane improves neurologic outcome after low-flow cardiopulmonary bypass in newborn pigs

BACKGROUND: Despite improvements in neonatal heart surgery, neurologic complications continue to occur from low-flow cardiopulmonary bypass (LF-CPB) and deep hypothermic circulatory arrest (DHCA). Desflurane confers neuroprotection against ischemia at normothermia and for DHCA. This study compared neurologic outcome of a desflurane-based with a fentanyl-based anesthetic for LF-CPB. METHODS: Thirty piglets aged 1 week received either fentanyl-droperidol (F/D), desflurane 4.5% (Des4.5), or desflurane 9% (Des9) during surgical preparation and CPB. Arterial blood gases, glucose, heart rate, arterial pressure, brain temperature, and cerebral blood flow (laser Doppler flowmetry) were recorded. After CPB cooling (22 degrees C brain) using pH-stat strategy, LF-CPB was performed for 150 min followed by CPB rewarming, separation from CPB, and extubation. On postoperative day 2, functional and histologic outcomes were assessed. RESULTS: Cardiovascular variables were physiologically similar between groups before, during, and after LF-CPB. Cerebral blood flow during LF-CPB (13% of pre-CPB value) did not differ significantly between the groups. Functional disability was worse in F/D than in Des9 (P = 0.04) but not Des4.5 (P = 0.1). In neocortex, histopathologic damage was greater in F/D than in Des4.5 (P = 0.03) and Des9 (P = 0.009). In hippocampus, damage was worse in F/D than in Des9 (P = 0.01) but not Des4.5 (P = 0.08). The incidences of ventricular fibrillation during LF-CPB were 90, 60, and 10% for F/D, Des4.5 (P = 0.06), and Des9 (P = 0.0002), respectively. CONCLUSIONS: Desflurane improved neurologic outcome following LF-CPB compared with F/D in piglets, indicated by less functional disability and less histologic damage, especially with Des9. Desflurane may have produced cardiac protection, suggested by a lower incidence of ventricular fibrillation.     

Desflurane Improves Neurologic Outcome after Low-flow Cardiopulmonary Bypass in Newborn Pigs

Background: Despite improvements in neonatal heart surgery, neurologic complications continue to occur from low-flow cardiopulmonary bypass (LF-CPB) and deep hypothermic circulatory arrest (DHCA). Desflurane confers neuroprotection against ischemia at normothermia and for DHCA. This study compared neurologic outcome of a desflurane-based with a fentanyl-based anesthetic for LF-CPB.

Methods: Thirty piglets aged 1 week received either fentanyl-droperidol (F/D), desflurane 4.5% (Des4.5), or desflurane 9% (Des9) during surgical preparation and CPB. Arterial blood gases, glucose, heart rate, arterial pressure, brain temperature, and cerebral blood flow (laser Doppler flowmetry) were recorded. After CPB cooling (22[degrees]C brain) using pH-stat strategy, LF-CPB was performed for 150 min followed by CPB rewarming, separation from CPB, and extubation. On postoperative day 2, functional and histologic outcomes were assessed.

Results: Cardiovascular variables were physiologically similar between groups before, during, and after LF-CPB. Cerebral blood flow during LF-CPB (13% of pre-CPB value) did not differ significantly between the groups. Functional disability was worse in F/D than in Des9 (P = 0.04) but not Des4.5 (P = 0.1). In neocortex, histopathologic damage was greater in F/D than in Des4.5 (P = 0.03) and Des9 (P = 0.009). In hippocampus, damage was worse in F/D than in Des9 (P = 0.01) but not Des4.5 (P = 0.08). The incidences of ventricular fibrillation during LF-CPB were 90, 60, and 10% for F/D, Des4.5 (P = 0.06), and Des9 (P = 0.0002), respectively.     

Xenon Impairs Neurocognitive and Histologic Outcome after Cardiopulmonary Bypass Combined with Cerebral Air Embolism in Rats

Background: The neuroprotective properties of xenon may improve cerebral outcome after cardiac surgery using cardiopulmonary bypass (CPB). However, its disposition to expand gaseous bubbles that during CPB present as cerebral air emboli (CAE) could abolish any beneficial effect or even worsen cerebral outcome. Therefore, the authors studied the impact of xenon on neurologic, cognitive, and histologic outcome after CPB combined with CAE in rats.

Methods: With institutional review board approval, 40 rats were assigned to four groups (n = 10). In two CPB-CAE groups, rats were subjected to 90 min of normothermic CPB with 10 repetitively administered CAEs (0.3 [mu]l/bolus). Rats in two sham groups were not exposed to CPB and CAE. Groups were further subdivided into xenon (56%; 20 min before, during, and 30 min after CPB) and nitrogen groups. Neurologic and cognitive function was tested until postoperative day 14, when cerebral infarct volumes were determined.

Results: Animals of the CPB-CAE groups showed transient deficits in gross neurologic function. Further, rats of the CPB-CAE-xenon group demonstrated impaired fine motor and cognitive performance persisting until postoperative day 14. Consistently, infarct volumes were larger in the CPB-CAE-xenon group compared with the CPB-CAE-nitrogen group (P = 0.03).     

地氟烷在二尖瓣置换手术中对缺血再灌注心肌的保护作用

在心脏外科手术中心肌缺血再灌注(ischemia-reperfusion,I-R)损伤的防治是急需解决的问题。缺血预处理(ischemic preconditioning,IPC)具有心肌保护作用[1,2]。研究显示挥发性麻醉药也具有类似IPC的麻醉药预处理(anesthetic-induced preconditioning,APC)作用[3,4],能减轻I-R后     

Xenon impairs neurocognitive and histologic outcome after cardiopulmonary bypass combined with cerebral air embolism in rats

BACKGROUND: The neuroprotective properties of xenon may improve cerebral outcome after cardiac surgery using cardiopulmonary bypass (CPB). However, its disposition to expand gaseous bubbles that during CPB present as cerebral air emboli (CAE) could abolish any beneficial effect or even worsen cerebral outcome. Therefore, the authors studied the impact of xenon on neurologic, cognitive, and histologic outcome after CPB combined with CAE in rats. METHODS: With institutional review board approval, 40 rats were assigned to four groups (n = 10). In two CPB-CAE groups, rats were subjected to 90 min of normothermic CPB with 10 repetitively administered CAEs (0.3 microl/bolus). Rats in two sham groups were not exposed to CPB and CAE. Groups were further subdivided into xenon (56%; 20 min before, during, and 30 min after CPB) and nitrogen groups. Neurologic and cognitive function was tested until postoperative day 14, when cerebral infarct volumes were determined. RESULTS: Animals of the CPB-CAE groups showed transient deficits in gross neurologic function. Further, rats of the CPB-CAE-xenon group demonstrated impaired fine motor and cognitive performance persisting until postoperative day 14. Consistently, infarct volumes were larger in the CPB-CAE-xenon group compared with the CPB-CAE-nitrogen group (P = 0.03). CONCLUSIONS: This is the first demonstration in which the neurologic effects of CAE have been examined in a rat model of CPB. Xenon exposure aggravated the neurologic dysfunction that is produced by CAE during CPB; potential neuroprotective effects of xenon may have been masked by the effects of xenon on CAE.     

Desflurane accelerates patient response during the wake-up test for scoliosis surgery

PURPOSE: To evaluate if desflurane possesses a shorter wake-up onset time and less incidence of recall than fentanyl-based anesthesia. METHODS: Forty ASA class I-II adolescents, were enrolled into either a desflurane (DES) group, or a fentanyl (FEN) group for scoliosis surgery. Bispectral index (BIS) was monitored continuously in all patients throughout the procedure; the relationship between the wake-up time and BIS value was evaluated. RESULTS: Patients in the DES group had a significantly shorter wake-up onset than patients in the FEN group (4.1 +/- 0.6 vs 8.9 +/- 2.1 min, P < 0.01). No recall occurred during the wake-up test in the DES group, while five patients had recall in the FEN group, including two patients who recalled a given colour. Extubation time was significantly shorter in the DES group than in the FEN group (7.2 +/- 0.6 vs 16 +/- 11.9 min, P < 0.01). BIS values were significantly higher in the FEN group than in the DES group during anesthesia. (62 +/- 4.5 vs 42 +/- 5.3, P < 0.05) BIS after the wake-up test was similar in both groups (90 +/- 2.9 vs 93.8 +/- 2.5). There was a latency period (3.3 +/- 1.2 min) between the maximal BIS value and wake-up time in the FEN group but not in the DES group. CONCLUSIONS: DES provides a significantly shorter onset time during the wake-up test and a rapid emergence after scoliosis surgery. BIS monitoring during the wake-up test was more informative when anesthesia was maintained with DES compared to FEN infusion.     

Cerebral air emboli differentially alter outcome after cardiopulmonary bypass in rats compared with normal circulation

BACKGROUND: Cerebral air emboli (CAE) are thought to contribute to adverse cerebral outcomes following cardiac surgery with cardiopulmonary bypass (CPB). This study was designed to investigate the effect of escalating volumes of CAE on survival and neurologic and histologic outcomes. In addition, the effect of xenon administration during CAE on these outcomes was determined. METHODS: With institutional review board approval, four groups were studied (n = 15). In two CPB-CAE groups, rats were subjected to 90 min CPB with 10 repetitively administered CAE. Rats in two sham-CAE groups were also exposed to CAE but not to CPB. Rats were randomly assigned to sequential dose cohorts receiving CAE ranging from 0.2 to 10 microl in a dose-escalating fashion. Groups were further subdivided into xenon (56%) and nitrogen groups. Rats with severe neurologic damage were killed; others were neurologically tested until postoperative day 7, when infarct volumes were determined. Survival and neurologic and histologic outcomes were tested with logistic regression analyses (P < 0.05). RESULTS: This study demonstrates a dose-dependent relation between CAE volumes and survival, neurologic outcome, and histologic outcome. For all outcomes, CPB adversely affected the dose-effect curves compared with sham-CAE groups (P < 0.05). Xenon demonstrated no impact on either outcome. CONCLUSIONS: This study describes the successful incorporation of CAE in a rodent CPB model and allows identifying suitable CAE volumes for subsequent studies. CAE exhibit a differential effect on outcome in rats undergoing CPB versus those not exposed to CPB. Perioperative administration of xenon remained without any effect on outcome.     

Large-dose pretreatment with methylprednisolone fails to attenuate neuronal injury after deep hypothermic circulatory arrest in a neonatal piglet model

Conflicting results have been reported with regard to the neuroprotective effects of steroid treatment with cardiopulmonary bypass (CPB) and deep hypothermic circulatory arrest (DHCA). We evaluated the mode and severity of neuronal cell injury in neonatal piglets after prolonged DHCA and the possible neuroprotective effect of systemic pretreatment (>6 h before surgery) with large-dose methylprednisolone (MP). Nineteen neonatal piglets (age, <10 days; weight, 2.1 +/- 0.5 kg) were randomly assigned to 2 groups: 7 animals were pretreated with large-dose systemic MP (30 mg/kg) 24 h before surgery, and 12 animals without pharmacological pretreatment (saline) served as control groups. All animals were connected to full-flow CPB with cooling to 15 degrees C and 120 min of DHCA. After rewarming to 38.5 degrees C with CPB, animals were weaned from CPB and survived 6 h before they were killed, and the brain was prepared for light and electron microscopy, immunohistochemistry, and TUNEL-staining. Quantitative histological studies were performed in hippocampus, cortex, cerebellum, and caudate nucleus. Systemic pretreatment with large-dose MP lead to persistent hyperglycemia but no significant changes of cerebral perfusion. Necrotic and apoptotic neuronal cell death were detected in all analyzed brain regions after 120 min of DHCA. In comparison to the control group, large-dose pretreatment with systemic MP lead to an increase of necrotic neuronal cell death and induced significant neuronal apoptosis in the dentate gyrus of the hippocampus (P = 0.001). In conclusion, systemic pretreatment with large-dose MP fails to attenuate neuronal cell injury after prolonged DHCA and induces regional neuronal apoptosis in the dentate gyrus.     

Cerebral Air Emboli Differentially Alter Outcome after Cardiopulmonary Bypass in Rats Compared with Normal Circulation

Background: Cerebral air emboli (CAE) are thought to contribute to adverse cerebral outcomes following cardiac surgery with cardiopulmonary bypass (CPB). This study was designed to investigate the effect of escalating volumes of CAE on survival and neurologic and histologic outcomes. In addition, the effect of xenon administration during CAE on these outcomes was determined.

Methods: With institutional review board approval, four groups were studied (n = 15). In two CPB-CAE groups, rats were subjected to 90 min CPB with 10 repetitively administered CAE. Rats in two sham-CAE groups were also exposed to CAE but not to CPB. Rats were randomly assigned to sequential dose cohorts receiving CAE ranging from 0.2 to 10 [mu]l in a dose-escalating fashion. Groups were further subdivided into xenon (56%) and nitrogen groups. Rats with severe neurologic damage were killed; others were neurologically tested until postoperative day 7, when infarct volumes were determined. Survival and neurologic and histologic outcomes were tested with logistic regression analyses (P < 0.05).

Results: This study demonstrates a dose-dependent relation between CAE volumes and survival, neurologic outcome, and histologic outcome. For all outcomes, CPB adversely affected the dose-effect curves compared with sham-CAE groups (P < 0.05). Xenon demonstrated no impact on either outcome.     

血管紧张素受体的表达在地氟醚预处理心肺转流前后的变化

目的　研究血管紧张素受体Ⅰ型、Ⅱ型 (AT1、AT2 )在地氟醚预处理心肺转流 (CPB)前后的变化。方法　选择行瓣膜置换术病人 2 0例 ,随机分为两组 :D组CPB前吸入 6 %～ 9%地氟醚 ,持续时间不少于 30min ;F组以芬太尼为主行全凭静脉麻醉。分别于CPB前后取右心耳组织约5 0mg ,逆转录聚合酶链式反应 (Rt PCR)测其中AT1、AT2受体的基因表达。 结果　两组病人在CPB前后AT1受体均有表达 ,组内比较无显著差异 (P >0 0 5 ) ,组间比较差异显著 ,即F组高于D组 (P<0 0 1 ,P <0 0 5 ) ;CPB前两组病人的AT2受体均无表达 ,CPB后均见AT2受体表达 ,以D组显著高于F组 (P <0 0 1 )。结论　血管紧张素受体参与了地氟醚预处理对缺血 再灌注心肌的影响     

Modified ultrafiltration may not improve neurologic outcome following deep hypothermic circulatory arrest.

OBJECTIVE: Modified ultrafiltration (MUF) improves systolic blood pressure and left ventricular performance, as well as lowering transfusion requirements, after cardiopulmonary bypass (CPB). MUF has also been shown to enhance acute cerebral metabolic recovery after deep hypothermic circulatory arrest (DHCA), but whether this improves neurologic outcome is unknown. METHODS: Sixteen neonatal piglets underwent CPB and 90 min of DHCA. The hematocrit was maintained between 25 and 30%. Alpha-stat blood gas management was used. After separation from CPB, animals were randomized to 15 min of MUF (n = 8) or no intervention (n = 8). Neurologic injury was assessed with behavior scores and histologic examination. Standardized behavior scores were obtained on post-operative days 1, 3, and 6 (0 = no deficit to 95 = brain death). The percentage of injured neurons by hematoxylin and eosin staining and the degree of reactive astrocytosis by glial filbrillary acidic protein (GFAP) immunohistochemistry were assessed to determine histologic scores in the neocortex and hippocampus (0 = no injury to 4 = diffuse injury). RESULTS: There were no statistically significant differences between groups during CPB. After MUF, the hematocrit was significantly higher (40% +/- 5.7 vs. 28% +/- 3.9, P < 0.001). There were no significant differences in behavior scores between groups (p > 0.1). There was resolution of deficits by day 6 in all animals. Neuronal injury was present in 81% (13/16) of the animals with no statistically significant differences between groups in incidence or severity. CONCLUSIONS: Use of MUF after DHCA does not prevent neuronal injury or improve neurologic outcome in this neonatal swine model.     

Early recovery, cognitive function and costs of a desflurane inhalational vs. a total intravenous anaesthesia regimen in long-term surgery

BACKGROUND: The purpose of the study was to compare time of recovery, return of cognitive function, post-anaesthetic care unit (PACU) stay and costs of a propofol/remifentanil (TIVA) with a desflurane/fentanyl-based anaesthesia (desflurane group) in surgical procedures lasting more than 150 min. METHODS: Forty-nine patients undergoing elective abdominal prostatectomy were allocated randomly to receive bispectal index (BIS)-controlled desflurane/fentanyl (n=24) or propofol/remifentanil (n=25). Awakening, clinical recovery, direct drug acquisition and post-operative pain treatment were documented. Cognitive skills were tested using the Mini-Mental Status (MMST) test. RESULTS: Extubation was significantly faster with desflurane (6.9+/-3.5 min) than with TIVA (11.2+/-4.0 min) as well as times for stating name and date of birth (desflurane: 6.1+/-3.9 and 6.6+/-4.0 min; TIVA: 12.4+/-11.5 min and 13.4+/-11.3 min). There were no significant differences in PACU discharge times or MMS scores between the groups. Significantly more patients suffered post-operative nausea and vomiting (PONV) in the desflurane (33% vs. 0%) than the TIVA group. Overall costs were significantly higher in the TIVA (58.8+/-11.6 euro) than in the desflurane group (35.0+/-5.7 euro). CONCLUSION: Patients undergoing prolonged surgical procedures showed a faster early recovery after desflurane/fentanyl than using TIVA, whereas stay in the PACU and recovery of cognitive function were similar in both groups. Costs of a TIVA regimen were significantly higher than using a desflurane-based anaesthesia technique.     

Desflurane--general anesthesia for cesarean section compared with isoflurane and epidural anesthesia

Desflurane 2.5% was compared to Isoflurane 0.5% in a randomized study in terms of maternal and newborn effect on both groups with epidural anesthesia. Fifty patients under general anesthesia were randomly designated to receive either desflurane 2.5% or isoflurane 0.5% maintained in a 50-50% nitrous oxide and oxygen mixture. Twenty-five patients were assigned to receive epidural anesthesia using 15 ml ropivacaine 7.5 mg/ml with fentanyl 100 micrograms. Intraoperative hemodynamic changes, blood loss and maternal awareness were recorded. Apgar scores at 1 and 5 min., neurologic adaptive capacity scores (NACS) at 2 and 24 hours and umbilical vein blood gas analysis were done to assess the neonatal outcome. Intraoperatively, heart rate and blood pressure changes were similar in both desflurane and Isoflurane group at 0.4% MAC (minimal alveolar concentration). Blood loss and arterial blood gas analysis were not problematic and did not differ significantly between the three groups. In the desflurane group, the patients were more easily awake and cooperative compared to the isoflurane group. The patients were interviewed about intraoperative awareness 24 and 48 h after the operation. None of them reported awareness during the operation. Similarly, the level of postoperative comfort was the same in both groups. Comparing the general and epidural anesthetic groups, no differences could be detected in neonatal outcomes. Conclusion is that there is one significant difference between desflurane 2.5% and isoflurane 0.5% anesthesia for cesarean section and it is the rapid recovery characteristic with desflurane which makes it an attractive alternative to TIVA (total intravenous anesthesia) and to other inhalational anesthetics available to obstetric anesthesiologists.     

Protective effect of sivelestat sodium (Eraspol) on postoperative lung dysfunction in patients with type A acute aortic dissection: a pilot study

AIM: The authors evaluated the protective effect of sivelestat sodium on postoperative lung dysfunction in patients with type A acute aortic dissection who underwent aortic arch surgery with cardiopulmonary bypass (CPB) under deep hypothermia with circulatory arrest (DHCA). METHODS: Twelve patients with type A acute aortic dissection who underwent aortic arch replacement under CPB with DHCA and were pretreated with or without sivelestat sodium (sivelestat group, N.=7 patients; control group, N.=5 patients) were observed. The ratio of arterial oxygen tension to inspired oxygen fraction (P/F ratio) was measured as a parameter of pulmonary function before and after operation. The number of white blood cells was also counted as an index of inflammatory reaction before and after the operation. RESULTS: The P/F ratio decreased significantly after operation in the control group. However, the P/F ratio was unchanged between before and after operation in the sivelestat group. The number of white blood cells tended to increase after operation in the control group, whereas it decreased significantly after operation in the sivelestat group. CONCLUSION: The present study demonstrated the protective effect of sivelestat sodium on postoperative lung injury in patients with acute type A aortic dissection undergoing aortic arch surgery under CPB with DHCA.     

Cardiopulmonary bypass induces neurologic and neurocognitive dysfunction in the rat.

BACKGROUND: Neurocognitive dysfunction is a common complication of cardiac surgery using cardiopulmonary bypass (CPB). Elucidating injury mechanisms and developing neuroprotective strategies have been hampered by the lack of a suitable long-term recovery model of CPB. The purpose of this study was to investigate neurologic and neurocognitive outcome after CPB in a recovery model of CPB in the rat. METHODS: Fasted rats (n = 10) were subjected to 60 min of normothermic (37.5 degrees C) nonpulsatile CPB using a roller pump and a membrane oxygenator. Sham-operated controls (n = 10) were not subjected to CPB. Neurologic outcome was assessed on days 1, 3, and 12 after CPB using standardized functional testing. Neurocognitive outcome, defined as the time (or latency) to finding a submerged platform in a Morris water maze (an indicator of visual-spatial learning and memory), was evaluated daily from post-CPB days 3-12. Histologic injury in the hippocampus was also evaluated. RESULTS: Neurologic outcome was worse in the CPB versus the sham-operated controls at all three measurement intervals (P < 0.001). The CPB group also had longer water maze latencies compared with the sham-operated controls (P = 0.004), indicating significant neurocognitive dysfunction after CPB. No difference in histologic injury between groups was observed. CONCLUSIONS: CPB caused both neurologic and neurocognitive impairment in a rodent recovery model. This model could potentially facilitate the investigation of CPB-related injury mechanisms and possible neuroprotective interventions.     

Effects of propofol,desflurane, and sevoflurane on recovery of myocardial function after coronary surgery in elderly high-risk patients

BACKGROUND: The present study investigated the effects of propofol, desflurane, and sevoflurane on recovery of myocardial function in high-risk coronary surgery patients. High-risk patients were defined as those older than 70 yr with three-vessel disease and an ejection fraction less than 50% with impaired length-dependent regulation of myocardial function. METHODS: Coronary surgery patients (n = 45) were randomly assigned to receive either target-controlled infusion of propofol or inhalational anesthesia with desflurane or sevoflurane. Cardiac function was assessed perioperatively and during 24 h postoperatively using a Swan-Ganz catheter. Perioperatively, a high-fidelity pressure catheter was positioned in the left and right atrium and ventricle. Response to increased cardiac load, obtained by leg elevation, was assessed before and after cardiopulmonary bypass (CPB). Effects on contraction were evaluated by analysis of changes in dP/dt(max). Effects on relaxation were assessed by analysis of the load-dependence of myocardial relaxation. Postoperative levels of cardiac troponin I were followed for 36 h. RESULTS: After CPB, cardiac index and dP/dt(max) were significantly lower in patients under propofol anesthesia. Post-CPB, leg elevation resulted in a significantly greater decrease in dP/dt(max) in the propofol group, whereas the responses in the desflurane and sevoflurane groups were comparable with the responses before CPB. After CPB, load dependence of left ventricular pressure drop was significantly higher in the propofol group than in the desflurane and sevoflurane group. Troponin I levels were significantly higher in the propofol group. CONCLUSIONS: Sevoflurane and desflurane but not propofol preserved left ventricular function after CPB in high-risk coronary surgery patients with less evidence of myocardial damage postoperatively.     

Emergence and recovery characteristics of desflurane versus sevoflurane in morbidly obese adult surgical patients: a prospective, randomized study

We compared postoperative recovery after desflurane (n = 25) versus sevoflurane (n = 25) anesthesia in morbidly obese adults (body mass index >/=35) who underwent gastrointestinal bypass surgery via an open laparotomy. After premedication with midazolam and metoclopramide 1 h before surgery, epidural catheter placement, induction of anesthesia with fentanyl and propofol, and tracheal intubation facilitated with succinylcholine, anesthesia was maintained with age-adjusted 1 minimum alveolar concentration (MAC) desflurane or sevoflurane. Fentanyl IV, morphine or local anesthetics epidurally, and vasoactive drugs as needed were used to maintain arterial blood pressure at +/-20% of baseline value and to keep bispectral index of the electroencephalogram values between 40 to 60 U. Although patients were anesthetized with desflurane for a longer time (261 +/- 50 min versus 234 +/- 37 min, mean +/- sd; P < 0.05, desflurane versus sevoflurane, respectively) and for more MAC-hours (4.2 +/- 0.9 h versus 3.7 +/- 0.8 h; P < 0.05), significantly earlier recovery of response to command and tracheal extubation occurred in patients given desflurane than in patients given sevoflurane. The modified Aldrete score was greater in desflurane-anesthetized patients on admission to the postanesthesia care unit (PACU) (P = 0.01) but not at discharge (P = 0.47). On admission to PACU, patients given desflurane had higher oxygen saturations (97.0% +/- 2.4%) than patients given sevoflurane (94.8% +/- 4.4%, P = 0.035). Overall, the incidence of postoperative nausea and vomiting and the use of antiemetics did not differ between the two anesthetic groups. We conclude that morbidly obese adult patients who underwent major abdominal surgery in a prospective, randomized study awoke significantly faster after desflurane than after sevoflurane anesthesia and the patients anesthetized with desflurane had higher oxygen saturation on entry to the PACU.     

Hemodynamic, hepatorenal, and postoperative effects of desflurane-fentanyl and midazolam-fentanyl anesthesia in coronary artery bypass surgery

OBJECTIVE: The purpose of this study was to compare the hemodynamic, hepatorenal, and postoperative effects of desflurane-fentanyl and midazolam-fentanyl anesthesia during coronary artery bypass surgery. DESIGN: Prospective study. SETTING: University hospital. PARTICIPANTS: Sixty patients undergoing elective coronary artery bypass grafting surgery with ejection fraction more than 45%. INTERVENTIONS: Anesthesia was induced with etomidate, 0.2 mg/kg, and fentanyl, 5 microg/kg, in group D (n = 30) and with midazolam, 0.1 to 0.3 mg/kg, and fentanyl, 5 microg/kg, in group M (n = 30). Anesthesia was maintained with desflurane, 2% to 6%, and fentanyl, 15 to 25 microg/kg, in group D and midazolam infusion, 0.1 to 0.5 mg/kg/h, and fentanyl, 15 to 25 microg/kg, in group M. MEASUREMENTS AND MAIN RESULTS: Hemodynamic monitoring included a 5-lead electrocardiogram, a radial artery catheter, and a pulmonary artery catheter. Data were obtained before induction of anesthesia (t0), after induction of anesthesia (t1), after intubation (t2), after surgical incision (t3), after sternotomy (t4), before cardiopulmonary bypass (t5), after protamine infusion (t6), and at the end of the surgery (t7). Blood samples were obtained to measure total bilirubin, aspartate aminotransferase, gamma glutamyl transferase, lactate dehydrogenase, alkaline phosphatase, creatinine, and blood urea nitrogen just before induction of anesthesia and at the first, fourth, and 14th days postoperatively. CONCLUSIONS: Intraoperative hemodynamic responses were similar in both groups, and transient hepatic and renal dysfunctions were observed in the postoperative period in both groups. The extubation and intensive care unit discharge times were found to be shorter in the desflurane-fentanyl group.     

Effects of Propofol, Desflurane, and Sevoflurane on Recovery of Myocardial Function after Coronary Surgery in Elderly High-risk Patients

Background: The present study investigated the effects of propofol, desflurane, and sevoflurane on recovery of myocardial function in high-risk coronary surgery patients. High-risk patients were defined as those older than 70 yr with three-vessel disease and an ejection fraction less than 50% with impaired length-dependent regulation of myocardial function.

Methods: Coronary surgery patients (n = 45) were randomly assigned to receive either target-controlled infusion of propofol or inhalational anesthesia with desflurane or sevoflurane. Cardiac function was assessed perioperatively and during 24 h postoperatively using a Swan-Ganz catheter. Perioperatively, a high-fidelity pressure catheter was positioned in the left and right atrium and ventricle. Response to increased cardiac load, obtained by leg elevation, was assessed before and after cardiopulmonary bypass (CPB). Effects on contraction were evaluated by analysis of changes in dP/dtmax. Effects on relaxation were assessed by analysis of the load-dependence of myocardial relaxation. Postoperative levels of cardiac troponin I were followed for 36 h.

Results: After CPB, cardiac index and dP/dtmax were significantly lower in patients under propofol anesthesia. Post-CPB, leg elevation resulted in a significantly greater decrease in dP/dtmax in the propofol group, whereas the responses in the desflurane and sevoflurane groups were comparable with the responses before CPB. After CPB, load dependence of left ventricular pressure drop was significantly higher in the propofol group than in the desflurane and sevoflurane group. Troponin I levels were significantly higher in the propofol group.