Plasma Inorganic Fluoride Concentrations after Sevoflurane Anesthesia in Children

Background: Sevoflurane is degraded in vivo in adults yielding plasma concentrations of inorganic fluoride [Fluorine sup -] that, in some patients, approach or exceed the 50-micro Meter theoretical threshold for nephrotoxicity. To determine whether the plasma concentration of inorganic fluoride [Fluorine sup -] after 1-5 MAC *symbol* h sevoflurane approaches a similar concentration in children, the following study in 120 children scheduled for elective surgery was undertaken.

Methods: Children were randomly assigned to one of three treatment groups before induction of anesthesia: group 1 received sevoflurane in air/oxygen 30% (n = 40), group 2 received sevoflurane in 70% N2 O/30% O2 (n = 40), and group 3 received halothane in 70% N2 O/30% O sub 2 (n = 40). Mapleson D or F circuits with fresh gas flows between 3 and 6 l/min were used. Whole blood was collected at induction and termination of anesthesia and at 1, 4, 6, 12, and 18 or 24 h postoperatively for determination of the [Fluorine sup -]. Plasma urea and creatinine concentrations were determined at induction of anesthesia and 18 or 24 h postoperatively.

Results: The mean (+/-SD) duration of sevoflurane anesthesia, 2.7+/-1.6 MAC *symbol* h (range 1.1-8.9 MAC *symbol* h), was similar to that of halothane, 2.5+/-1.1 MAC *symbol* h. The peak [Fluorine sup -] after sevoflurane was recorded at 1 h after termination of the anesthetic in all but three children (whose peak values were recorded between 4 and 6 h postanesthesia). The mean peak [Fluorine sup -] after sevoflurane was 15.8+/-4.6 micro Meter. The [Fluorine sup -] decreased to < 6.2 micro Meter by 24 h postanesthesia. Both the peak [Fluorine sup -] (r2 = 0.50) and the area under the plasma concentration of inorganic fluoride-time curve (r2 = 0.57) increased in parallel with the MAC *symbol* h of sevoflurane. The peak [Fluorine sup -] after halothane, 2.0+/-1.2 micro Meter, was significantly less than that after sevoflurane (P < 0.0001) and did not correlate with the duration of halothane anesthesia (MAC *symbol* h; r2 = 0.007). Plasma urea concentrations decreased 24 h after surgery compared with preoperative values for both anesthetics (P < 0.01), whereas plasma creatinine concentrations did not change significantly with either anesthetic.     

Sevoflurane Depresses Myocardial Contractility Less than Halothane during Induction of Anesthesia in Children

Background: Cardiovascular stability is an important prerequisite for any new volatile anesthetic. We compared echocardiographically derived indices of myocardial contractility during inhalation induction with sevoflurane and halothane in children.

Methods: Twenty children were randomized to receive either halothane or sevoflurane for inhalation induction of anesthesia. No preoperative medications were given. Myocardial contractility was evaluated at baseline and at sevoflurane and halothane end-tidal concentrations of 1.0 minimum alveolar concentration (MAC) and 1.5 MAC.

Results: There were no differences between groups in patient age, sex, physical status, weight, or height. Equilibration times and MAC multiples of sevoflurane and halothane were comparable. Vital signs remained stable throughout the study. Left ventricular end-systolic meridional wall stress increased with halothane but remained unchanged with sevoflurane. Systemic vascular resistance decreased from baseline to 1 MAC and 1.5 MAC with sevoflurane. Halothane depressed contractility as assessed by the stress-velocity index and stress-shortening index, whereas contractility remained within normal limits with sevoflurane. Total minute stress and normalized total mechanical energy expenditure, measures of myocardial oxygen consumption, did not change with either agent.     

右美托咪啶对小儿七氟烷吸入全麻的影响

目的:观察右美托咪啶对小儿上肢手术七氟烷吸入全麻效果的影响。方法:拟在吸入七氟烷诱导麻醉下行择期上肢手术的小儿患者120例,随机分为3组(n=40):对照组(c组)、低、高剂量右美托咪啶组(D1-2组),分别在麻醉诱导前15min静脉输注15mL生理盐水、右美托咪啶0.25μg/kg和0.5μg/kg(药物浓度为0.5μg/mL)。分别于输注生理盐水(或右美托咪啶)前(T0)、神经阻滞前(T1)、神经阻滞时刻(T2)、切皮时(T3)、手术30min(T4)、手术结束(T5)时记录各时间点BIS值、MAP、HR、呼吸末七氟烷浓度(CE)和呼吸功能指标(VT、MV、PETCO2、RR和SPO2),以及诱导时间、手术出血量。结果:与C组比较,D1、D2组诱导时间明显缩短(P<0.05);与C组和D1组比较,D2组T2~5时点的BIS值均明显降低;与D1组比较,D2组T4时点的CE值显著降低(P<0.05);与C组和D1组比较,D2组T1~5时点的MAP、HR值均降低(P<0.05);与C组相比,D1、D2组在T3~4时点的VT、MV值降低,差异有统计学意义(P<0.05)。结论:右美托咪啶能够加快小儿上肢手术七氟烷诱导时间,减少吸入麻醉药用量,血流动力学稳定和镇静加强,但高剂量右美托咪啶对循环及呼吸有一定抑制作用。     

Anesthesia Depth-dependent Features of Electroencephalographic Bicoherence Spectrum during Sevoflurane Anesthesia

Background: Growth pattern in the electroencephalographic bicoherence spectrum has recently been found to relate to anesthetic depth, and bicoherence analysis can reflect behavior of the thalamocortical reverberating network. Because the thalamocortical network is known to represent a key factor in sleep by anesthesia, systematic and qualitative bicoherence studies of different anesthetic depths is necessary throughout all pairs of frequencies.

Methods: Sixteen patients were anesthetized using sevoflurane (1, 2, or 3%) combined with remifentanil (0.4 [mu]g [middle dot] kg-1 [middle dot] min-1). Raw electroencephalographic signals were collected, and bicoherence was estimated in all pairs of frequencies, between 0.5 and 40 Hz at 0.5-Hz intervals.

Results: Sevoflurane (1%) caused two main peaks, spindle frequencies (11.0 +/- 1.2 Hz, 44.7 +/- 12.3% [bicoherence growth]) and [delta]-[theta] frequencies (5.4 +/- 0.5 Hz, 33.0 +/- 8.4%), in the diagonal line of biphasic bicoherence plots. High concentrations of sevoflurane (2% and 3%) shifted these peaks to 9.8 +/- 1.1 Hz, 46.2 +/- 12.7%; 8.7 +/- 1.3 Hz, 37.2 +/- 13.7% and 4.9 +/- 0.5 Hz, 44.6 +/- 7.0%; 4.3 +/- 0.8 Hz, 45.2 +/- 10.6%, respectively. Sevoflurane caused a third bicoherence peak to appear in another heterogeneous pair frequency (pair of [alpha] basal frequency and its double frequency), outside the diagonal line, which also inherited the behavior of [alpha] bicoherence peaks at different anesthetic depths.     

Effects of the Water Content of Soda Lime on Compound A Concentration in the Anesthesia Circuit in Sevoflurane Anesthesia

Background: Sevoflurane anesthesia is usually performed with fresh gas flow rates greater than 2 l/min due to the toxicity of compound A in rats and limited clinical experience with sevoflurane in low-flow systems. However, to reduce costs, it would be useful to identify ways to reduce compound A concentrations in low-flow sevoflurane anesthesia. This goal of this study was to determine if compound A concentrations can be reduced by using soda lime with water added.

Methods: Low-flow sevoflurane anesthesia (fresh gas flow of 1 l/min) was performed in 37 patients using soda lime with water added (perhydrated soda lime) or standard soda lime as the carbon dioxide (CO sub 2) absorbent. The soda lime was not changed between patients, but rather was used until CO2 rebreathing occurred. The perhydrated soda lime was prepared by spraying 100 ml distilled water onto 1 kg fresh soda lime, and water was added only when a new bag of soda lime was placed into the canister. Compound A concentrations in the circle system, soda lime temperatures, inspired and end-tidal CO2 and end-tidal sevoflurane concentrations, and CO2 elimination by the patient were measured during anesthesia.

Results: Compound A concentrations were significantly lower for the perhydrated soda lime (1.9 +/- 1.8 ppm; means +/- SD) than for the standard soda lime (13.9 +/- 8.2 ppm). No differences were seen between the two types of soda lime with regard to the temperature of the soda lime, end-tidal sevoflurane concentrations, or CO2 elimination. Compound A concentration decreased with the total time of soda lime use for both types of soda lime. The CO2 absorption capacity was significantly less for perhydrated soda lime than for standard soda lime.     

Use of Intranasal Fentanyl in Children Undergoing Myringotomy and Tube Placement during Halothane and Sevoflurane Anesthesia

Background: Many children are restless, disoriented, and inconsolable immediately after bilateral myringotomy and tympanosotomy tube placement (BMT). Rapid emergence from sevoflurane anesthesia and postoperative pain may increase emergence agitation. The authors first determined serum fentanyl concentrations in a two-phase study of intranasal fentanyl. The second phase was a prospective, placebo-controlled, double-blind study to determine the efficacy of intranasal fentanyl in reducing emergence agitation after sevoflurane or halothane anesthesia.

Methods: In phase 1, 26 children with American Society of Anesthesiologists (ASA) physical status I or II who were scheduled for BMT received intranasal fentanyl, 2 [mu]g/kg, during a standardized anesthetic. Serum fentanyl concentrations in blood samples drawn at emergence and at postanesthesia care unit (PACU) discharge were determined by radioimmunoassay. In phase 2, 265 children with ASA physical status I or II were randomized to receive sevoflurane or halothane anesthesia along with either intranasal fentanyl (2 [mu]g/kg) or saline. Postoperative agitation, Children's Hospital of Eastern Ontario Pain Scale (CHEOPS) scores, and satisfaction of PACU nurses and parents with the anesthetic technique were evaluated.

Results: In phase 1, the mean fentanyl concentrations at 10 +/- 4 min (mean +/- SD) and 34 +/- 9 min after administering intranasal fentanyl were 0.80 +/- 0.28 and 0.64 +/- 0.25 ng/ml, respectively. In phase 2, the incidence of severe agitation, highest CHEOPS scores, and heart rate in the PACU were decreased with intranasal fentanyl. There were no differences between sevoflurane and halothane in these measures and in times to hospital discharge. The incidence of postoperative vomiting, hypoxemia, and slow respiratory rates were not increased with fentanyl.     

Changes in Electroencephalogram and Autonomic Cardiovascular Activity during Induction of Anesthesia with Sevoflurane Compared with Halothane in Children

Background: This study was design to assess clinical agitation, electroencephalogram (EEG) and autonomic cardiovascular activity changes in children during induction of anesthesia with sevoflurane compared with halothane using noninvasive recording of EEG, heart rate, and finger blood pressure.

Methods: Children aged 2-12 yr premedicated with midazolam were randomly assigned to one of three induction techniques: 7% sevoflurane in 100% O2 (group SevoRAPID); 2%, 4%, 6%, and 7% sevoflurane in 100% O2 (group SevoINCR); or 1%, 2%, 3%, and 3.5% halothane in 50% N2O-50% O2 (group HaloN2O). An additional group of children who received 7% sevoflurane in 50% N2O-50% O2 (group SevoN2O) was enrolled after completion of the study. Induction was videotaped. EEG, heart rate, and finger blood pressure were continuously recorded during induction until 5 min after tracheal intubation and analyzed in frequency domain using spectral analysis.

Results: Agitation was more frequent when anesthesia was induced with 100% O2 compared to the mixture of oxygen and nitrous oxide. No seizures were recorded in any group. In the four groups, induction of anesthesia was associated with an increase in EEG total spectral power and a shift toward the low-frequency bands. Sharp slow waves were present on EEG tracings of the three sevoflurane groups, whereas slow waves and fast rhythms (spindles) were observed in the halothane group. Sevoflurane induced a greater withdrawal of parasympathetic activity than halothane and a transient relative increase in sympathetic vascular tone at loss of eyelash reflex.     

Epileptiform Electroencephalogram during Mask Induction of Anesthesia with Sevoflurane

Background: Sevoflurane is suggested as a suitable anesthetic agent for mask induction in adults. The authors recently found that hyperventilation during sevoflurane-nitrous oxide-oxygen mask induction is associated with cardiovascular hyperdynamic response. We tested the hypothesis that the hyperdynamic response can be explained by electroencephalography (EEG) findings.

Methods: Thirty women were randomly allocated to receive sevoflurane-nitrous oxygen-oxygen mask induction using a single-breath method, followed by either spontaneous breathing (n = 15) or controlled hyperventilation (n = 15) for 6 min. EEG was recorded. Blood pressure and heart rate were recorded at 1-min intervals.

Results: Epileptiform EEG activity (spikes or polyspikes) was seen in all patients with controlled hyperventilation, and in seven patients with spontaneous breathing (P< 0.01). Jerking movements were seen in three patients with controlled hyperventilation. In the controlled hyperventilation group, heart rate increased 54% from baseline at 4 min after induction (P< 0.001). Mean arterial pressure increased 17% (P< 0.05), peaking at 3 min. In the spontaneous breathing group, heart rate showed no change, and mean arterial pressure decreased by 14% (P< 0.01) at 6 min. Heart rate and mean arterial pressure differed significantly between the groups from 2 min after beginning of the induction to the end of the trial. An increase in heart rate of more than 30% from baseline always was associated with epileptiform EEG activity.     

Absence of Bronchodilation during Desflurane Anesthesia: A Comparison to Sevoflurane and Thiopental

Background: Bronchospasm is a potential complication in anyone undergoing general anesthesia. Because volatile anesthetics relax bronchial smooth muscle, the effects of two newer volatile anesthetics, desflurane and sevoflurane, on respiratory resistance were evaluated. The authors hypothesized that desflurane would have greater bronchodilating effects because of its ability to increase sympathetic nervous system activity.

Methods: Informed consent was obtained from patients undergoing elective surgery with general anesthesia. We recorded airway flow and pressure after thiopental induction and tracheal intubation (baseline) and for 10 min after beginning volatile anesthesia (~ 1 minimum alveolar concentration inspired). Respiratory system resistance was determined using the isovolume technique.

Results: Fifty subjects were randomized to receive sevoflurane (n = 20), desflurane (n = 20), or thiopental infusion (n = 10, 0.25 mg [middle dot] kg-1 [middle dot] h-1). There were no differences between groups for age, height, weight, smoking history, and American Society of Anesthesiologists physical class. On average, sevoflurane reduced respiratory resistance 15% below baseline, whereas both desflurane (+5%) and thiopental (+10%) did not decrease respiratory resistance. The respiratory resistance changes did not differ in patients with and without a history of smoking during sevoflurane or thiopental. In contrast, administration of desflurane to smokers resulted in the greatest increase in respiratory resistance.     

Graded Hypercapnia and Cerebral Autoregulation during Sevoflurane or Propofol Anesthesia

Background: Hypercapnia abolishes cerebral autoregulation, but little is known about the interaction between hypercapnia and autoregulation during general anesthesia. With normocapnia, sevoflurane (up to 1.5 minimum alveolar concentration) and propofol do not impair cerebral autoregulation. This study aimed to document the level of hypercapnia required to impair cerebral autoregulation during propofol or sevoflurane anesthesia.

Methods: Eight healthy subjects received a remifentanil infusion and were anesthetized with propofol (140 [mu]g [middle dot] kg-1 [middle dot] min-1) and sevoflurane (1.0-1.1% end tidal) in a randomized crossover study. Ventilation was adjusted to achieve incremental increases in arterial carbon dioxide partial pressure (Paco2) until autoregulation was impaired. Cerebral autoregulation was tested by increasing the mean arterial pressure (MAP) from 80 to 100 mmHg with phenylephrine while measuring middle cerebral artery flow velocity by transcranial Doppler. The autoregulation index, which has a value ranging from 0 to 1, representing absent to perfect autoregulation, was calculated, and an autoregulation index of 0.4 or less represented significantly impaired autoregulation.

Results: The threshold Paco2 to significantly impair cerebral autoregulation ranged from 50 to 66 mmHg. The threshold averaged 56 +/- 4 mmHg (mean +/- SD) during sevoflurane anesthesia and 61 +/- 4 mmHg during propofol anesthesia (P = 0.03). Carbon dioxide reactivity measured at a MAP of 100 mmHg was 30% greater than that at a MAP of 80 mmHg.     

Anesthesia with Sevoflurane in Bariatric Surgery

Background: Sevoflurane is a good halogen agent for bariatric surgery anesthesia because of its physical and chemical characteristics and its repartition coefficient (blood/gas = 0.65). Method: From November 1997 to April 1998, 98 bariatric surgery procedures with sevoflurane anesthesia were done: 17 lipectomies, 71 vertical gastroplasties, and 10 biliopancreatic diversions in 71 women and 27 men, average age 30.3 ± 8.3 years, with body mass index 43.9 ± 5.7. The average operating time was 50 ± 15 minutes for vertical gastroplasty, 160 ± 20 minutes for biliopancreatic diversion, and 80 ± 12 minutes for lipectomy. The technique of anesthesia was as follows: preanesthesia with atropine sulfate 0.01 mg/kg (dosage refers to ideal weight), ranitidine 50 mg, fentanyl 0.1 mg, ketorolac 60 mg; induction with propofol 0.5-1 mg/kg, succinylcholine 1 mg/kg; orotracheal intubation; maintenance with O2-N2O 50%, sevoflurane 1% to 1.5%, actracurium 0.5 mg/kg (dosage refers to ideal weight); awakening and decurarization with atropine sulfate 1 mg and prostigmine 2 mg. Results: This method permitted correct control of the anesthesia, a quick awakening with a low incidence of nausea and vomiting, a prompt regain of physical and psychological functioning, an early discharge from the hospital, and a larger turnover of patients with lower costs. Conclusion: Sevoflurane balanced anesthesia seems to be the best anesthesiologic method for bariatric surgery.     

Recovery from Sevoflurane Anesthesia: A Comparison to Isoflurane and Propofol Anesthesia

Backgroud: 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.     

Effects of Low-flow Sevoflurane Anesthesia on Renal Function: Comparison with High-flow Sevoflurane Anesthesia and Low-flow Isoflurane Anesthesia

Background: The safety of low-flow sevoflurane anesthesia, during which CF2 = C(CF3)-O-CH2 F (compound A) is formed by sevoflurane degradation, in humans has been questioned because compound A is nephrotoxic in rats. Several reports have evaluated renal function after closed-circuit or low-flow sevoflurane anesthesia, using blood urea nitrogen (BUN) and serum creatinine as markers. However, these are not the more sensitive tests for detecting renal damage. This study assessed the effects of low-flow sevoflurane anesthesia on renal function using not only BUN and serum creatinine but also creatinine clearance and urinary excretion of kidney-specific enzymes, and it compared these values with those obtained in high-flow sevoflurane anesthesia and low-flow isoflurane anesthesia.

Methods: Forty-eight patients with gastric cancer undergoing gastrectomy were studied. Patients were randomized to receive sevoflurane anesthesia with fresh gas flow of 1 l/min (low-flow sevoflurane group; n = 16) or 6-10 l/min (high-flow sevoflurane group; n = 16) or isoflurane anesthesia with a fresh gas flow of 1 l/min (low-flow isoflurane group; n = 16). In all groups, the carrier gas was oxygen/nitrous oxide in the ratio adjusted to ensure a fractional concentration of oxygen in inspired gas (FiO2) of more than 0.3. Fresh Baralyme was used in the low-flow sevoflurane and low-flow isoflurane groups. Glass balls were used instead in the high-flow sevoflurane group, with the fresh gas flow rate adjusted to eliminate rebreathing. The compound A concentration was measured by gas chromatography. Gas samples taken from the inspiratory limb of the circle system at 1-h intervals were analyzed. Blood samples were obtained before and on days 1, 2, and 3 after anesthesia to measure BUN and serum creatinine. Twenty-four-hour urine samples were collected before anesthesia and for each 24-h period from 0 to 72 h after anesthesia to measure creatinine, N-acetyl-beta-D-glucosaminidase, and alanine aminopeptidase.

Results: The average inspired concentration of compound A was 20 +/- 7.8 ppm (mean +/- SD), and the average duration of exposure to this concentration was 6.11 +/- 1.77 h in the low-flow sevoflurane group. Postanesthesia BUN and serum creatinine concentrations decreased, creatinine clearance increased, and urinary N-acetyl-beta-D-glucosaminidase and alanine aminopeptidase excretion increased in all groups compared with preanesthesia values, but there were no significant differences between the low-flow sevoflurane, high-flow sevoflurane, and low-flow isoflurane groups for any renal function parameter at any time after anesthesia.     

Greater Incidence of Delirium during Recovery from Sevoflurane Anesthesia in Preschool Boys

Background: In the authors' clinical experience, preschool children are more likely to show delirium after sevoflurane than are older children.

Methods: Sixty-three preschool boys aged 3-5 yr (classified as American Society of Anesthesiologists [ASA] physical status I), and 53 school-age boys aged 6-10 yr (ASA physical status I) who underwent minor urologic surgery were randomly assigned to receive either halothane or sevoflurane, thus creating four groups: preschool-halothane (n = 32), preschool-sevoflurane (n = 31), school-halothane (n = 27), and school-sevoflurane (n = 26). Anesthesia was induced by inhalation of halothane or sevoflurane in oxygen and was maintained at 1 minimum alveolar concentration of each agent throughout surgery. For intra- and postoperative analgesia, caudal block with 0.5-1.0 ml/kg 0.25% plain bupivacaine and topical infiltration with 3-5 ml 1% lidocaine were provided for all patients. Recovery characteristics and incidence of delirium on emergence were compared among the four groups.

Results: Two patients in the preschool-halothane group, one in the preschool-sevoflurane group, and one in the school-halothane group were excluded from the comparison because of insufficient analgesia or agitation before induction. In both age groups, the time to emergence from sevoflurane was significantly faster (about 3 min) than from halothane. The incidence of delirium during recovery in the preschool-sevoflurane group (40%) was significantly greater than that in the other groups (preschool-halothane, 10%; school-halothane, 15.4%; school-sevoflurane, 11.5%).     

Leukocyte-Endothelium Interaction in the Rat Mesenteric Microcirculation during Halothane or Sevoflurane Anesthesia

Background: The effects of inhalational anesthetics on the microcirculation, including leukocyte dynamics, remain to be clarified. The authors investigated halothane and sevoflurane anesthesia to determine if these agents evoked leukocyte adhesion through endothelial cell-dependent mechanisms involving such adhesion molecules.

Methods: Rats were anesthetized with halothane or sevoflurane in 100% oxygen and the lungs were mechanically ventilated. Leukocyte behavior in mesenteric venules was recorded through intravital video microscopy under monitoring microvascular hemodynamics. To examine the mechanisms for leukocyte rolling and adhesion, these studies were repeated after animals were pretreated with a monoclonal antibody against P-selectin (MAb PB1.3) or against intracellular adhesion molecule-1 (ICAM-1; MAb 1A29): P-selectin required for rolling of circulating leukocytes and ICAM-1 for firm adhesive interactions with leukocyte integrins.

Results: Under baseline anesthetic conditions (1 minimum alveolar concentration [MAC]), venular wall shear rates, an index of the disperse force on marginating leukocytes, in the sevoflurane-treated rats were about two times higher than those with halothane. At 2 MAC, halothane caused a marked arteriolar constriction and decreasing shear rates concurrent with an increasing density of venular leukocyte adhesion. Sevoflurane at 2 MAC induced leukocyte rolling and adhesion, which were attenuated by PB1.3 and 1A29, without alterations in the wall shear rates. Halothane-induced leukocyte adhesion was not prevented by PB1.3 but it was by 1A29.