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The purpose of this study was to evaluate intraoperative glucose control.Prospective unblinded study.Tertiary care center.Diabetic (n = 17) and nondiabetic (n = 23) patients undergoing elective cardiac surgery.Diabetics received a modified insulin regimen consisting of a fixed rate infusion of regular insulin, 10 U/m2/h, and a variable infusion of D10W, adjusted to maintain glucose between 101 to 140 mg/dL.Baseline glucose was higher in diabetics versus nondiabetics (mean +/- standard error of the mean: 203 +/- 27 v 117 +/- 3 mg/dL, p0.005). After baseline, insulin levels were increased in diabetics to 410 to 568 microU/mL. Corresponding insulin levels in nondiabetics were 12 to 40 microU/mL. Compared with baseline, glucose was decreased by 10% +/- 29% in diabetics during hypothermic cardiopulmonary bypass and increased by 21% +/- 30% in nondiabetics (p0.005). After discontinuation of bypass, glucose was lower in diabetics (137 +/- 12 mg/dL) versus nondiabetics (162 +/- 8 mg/dL, p0.005). Nine diabetics had adequate intraoperative glycemic control during hypothermic bypass (glucose 123 +/- 8 mg/dL, insulin 550 +/- 68 microU/mL, glucose infusion rate 1.87 +/- 0.29 mg/kg/min), 6 approached adequate control near the end of surgery (glucose 147 +/- 8 mg/dL, insulin 483 +/- 86 microU/mL, glucose infusion rate 0.35 +/- 0.05 mg/kg/min), and 2 never achieved control. Diabetics with elevated initial glucose300 mg/dL did not achieve adequate glycemic control. Four diabetics (3 with renal failure) required injection of 50% dextrose after bypass for hypoglycemia.Adequate glycemic control can be achieved in most diabetics during cardiac surgery using a modified insulin clamp technique provided initial glucose is300 mg/dL.

To compare a sevoflurane-nitrous oxide (N2O) general anesthetic technique with a standard technique of propofol for induction, and isoflurane-N2O for maintenance.Prospective, randomized study.University-affiliated tertiary-care hospital.62 adults undergoing elective surgery using the laryngeal mask airway (LMA).Patients received either the standard technique of propofol for induction and isoflurane-N2O for maintenance (controls) or sevoflurane-N2O for both induction and maintenance of general anesthesia.Induction and emergence times, heart rate, blood pressure, oxygen saturation, and end-tidal carbon dioxide were recorded.Time to loss of consciousness was faster after propofol (mean +/- SEM: 51 +/- 3 sec) than after sevoflurane-N2O (85 +/- 10 sec; p0.05). Ready for surgery times, were however, similar between groups (10 +/- 1 vs. 11 +/- 1 min, respectively). All patients in the control group had apnea after LMA insertion compared with 4 patients in the sevoflurane-N2O group (p0.05). Heart rate was lower 5 and 10 minutes after LMA insertion in the sevoflurane-N2O group (69 +/- 3 and 66 +/- 3 bpm) versus the control group (81 +/- 3 bpm and 74 +/- 3 bpm, p0.05). After cessation of anesthetic gases, there were no differences in time to LMA removal, eye opening, or exiting the operating room (OR) between the control group (7, 8, and 10 min) and sevoflurane-N2O groups (7, 8, and 12 min, respectively). The majority of patients in both groups (92% to 97%) rated their anesthetic experience as excellent or good.Sevoflurane-N2O and propofol provided comparable conditions for LMA insertion. Sevoflurane-N2O was not associated with a faster return of consciousness or faster time to exit the OR compared with isoflurane-N2O.

Objective: To determine the patterns of oxygen consumption (Vo 2 ) using indirect calorimetry (IC) for the first 24 hrs after serious blunt traumatic injury. Design: Prospective, observational study. Setting: Surgical intensive care unit of a Level 1 trauma center. Patients: Sixty-six mechanically ventilated patients with blunt traumatic injury and Injury Severity Score >15. Interventions: IC for 24 hrs postinjury. Patients were resuscitated to standard parameters of perfusion. Measurements and Main Results: Mean patient age was 50.1 ± 18.7 yrs with a mean Injury Severity Score 30.7 ± 11.3). Mean Vo 2 for all patients for the 24-hr study period was 168.5 ± 29.5 mL/min/m 2 , The level of Vo 2 was not related to Injury Severity Score, the number or combination of organ systems injured, or to the use of vasoactive agents. Patients >65 yrs of age had significantly lower Vo 2 (p =.0038) compared with patients ≤50 yrs. Vo 2 did not change over time after resuscitation to normal parameters of perfusion. Mean Vo 2 was 156.5 ± 63.2 mL/min/m 2 in patients who developed multiple organ dysfunction, and 172.4 ± 33.3 mL/min/m 2 in those who did not develop multiple organ dysfunction (p =.16). Conclusions: Seriously injured patients are hypermetabolic in the early postinjury period. The level of Vo 2 is unrelated to injury severity or number of organ systems involved. Elderly patients can be expected to have lower levels of Vo 2 . Vo 2 does not change significantly in response to resuscitation to normal parameters of perfusion. Vo 2 measured by IC did not predict the development of multiple organ dysfunction.

Objective: To evaluate the neuromuscular, ventilatory, and cardiovascular effects of rocuronium and vecuronium. Design: Randomized, prospective, blinded study. Setting: Tertiary care teaching center, single institution. Participants: Patients undergoing elective coronary artery bypass graft procedure. Interventions: Patients received rocuronium, 1.0 mg/kg (n = 17), or vecuronium, 0.15 mg/kg (n = 15), during fentanyl induction of anesthesia. Measurements and Main Results: Measures consisted of time to visual loss of orbicularis oculi twitches in response to facial nerve stimulation, ease of mask ventilation, hemodynamics, need for vasoactive drugs, and tracheal intubating conditions. Median time to twitch loss was faster (p 84 s). Within 45 seconds, only 3 of 17 patients in the rocuronium group had moderate-to-severe difficulty with mask ventilation versus 12 of 15 patients in the vecuronium group (p < 0.05). Tracheal intubating conditions were excellent in all patients after rocuronium. In the vecuronium group, intubating conditions were excellent in 46%, good in 27%, and poor in 27% (p < 0.05v rocuronium). Patients receiving vecuronium were more likely to require ephedrine and phenylephrine for hypotension (1015 patients v 517 patients for rocuronium, p < 0.05). There were no clinically important differences in hemodynamic variables, oxygen metabolism, or myocardial ischemia between groups. Conclusion: During narcotic induction of anesthesia, rocuronium was associated with lower requirement for vasopressors, faster onset of neuromuscular blockade, and better conditions for mask ventilation and tracheal intubation compared with vecuronium.

To test the hypothesis that warming intravenous (i.v.) fluids in conjunction with convective warming results in less intraoperative hypothermia (core temperature36.0 degrees C) than that seen with convective warming alone.Prospective, randomized study.University affiliated tertiary care teaching hospital.61 ASA physical status, I, II, and III adults undergoing major surgery and general anesthesia with isoflurane.All patients received convective warming. Group 1 patients received warmed fluids (setpoint 42 degrees C). Group 2 patients received room temperature fluids (approximately 21 degrees C).Lowest and final intraoperative distal esophageal temperatures were higher (p0.05) in Group 1 (mean +/- SEM: 35.8 +/- 0.1 degrees C and 36.6 +/- 0.1 degrees C) versus Group 2 (35.4 +/- 0.1 degrees C and 36.1 +/- 0.1 degrees C, respectively). Compared with Group 1, more Group 2 patients were hypothermic at the end of anesthesia (10 of 26 patients, or 38.5% vs. 4 of 30 patients, or 13%; p0.05). After 30 minutes in the recovery room, there were no differences in temperature between groups (36.7 +/- 0.1 degrees C and 36.5 +/- 0.1 degrees C in Groups 1 and 2, respectively). Intraoperative cessation of convective warming because of core temperature greater than 37 degrees C was required in 33% of Group 1 patients (vs. 11.5% in Group 2; p = 0.052).The combination of convective and fluid warming was associated with a decreased likelihood of patients leaving the operating room hypothermic. However, average final temperatures were greater than 36 degrees C in both groups, and intergroup differences were small. Care must be taken to avoid overheating the patient when both warming modalities are employed together.

We evaluated whether warming i.v. fluids resulted in less hypothermia (core temperature35.5 degrees C) compared with room-temperature fluids. Thirty-eight adult outpatients undergoing elective gynecological surgery of30 min were randomized to two groups: fluid warming at 42 degrees C or control (room temperature fluids at approximately 21 degrees C). All patients received general anesthesia with isoflurane, tracheal intubation, standard operating room blankets and surgical drapes, and passive humidification of inspired gases. Tympanic membrane (core) temperatures were measured at baseline and at 15-min intervals after induction. The incidence of shivering and postoperative requirement for meperidine and/or radiant heat were evaluated. Core temperatures were lower in the control compared with the warm fluid group at the end of surgery (35.6 +/- 0.1 degrees C vs 36.2 +/- 0.1 degrees C; P0.05). More patients had final core temperature35.5 degrees C in the control compared with the warm fluid group (35% vs 0%; P0.05). There were no differences in time to discharge from the postanesthesia care unit or the incidence of shivering between the groups. We conclude that fluid warming, in conjunction with standard heat conservation measures, was effective in maintaining normothermia during outpatient gynecological surgery; however, there was no improvement in patient outcome.Women who received i.v. fluid at body temperature had significantly higher core temperatures during and after outpatient gynecological surgery compared with women who received i.v. fluids at the temperature of the operating room.

Objective The purpose of this study was to evaluate the relation of oxygen delivery (DO 2 ) to the occurrence of multiple organ dysfunction (MOD) in patients with ruptured abdominal aortic aneurysms (AAA). Background Data Patients with ruptured AAA are at high risk for the development of MOD and death. Previous reports of high-risk general surgical patients have shown improved survival when higher levels of DO 2 are achieved. Methods Hemodynamic data were collected at 4-hour intervals on 57 consecutive patients (mean age, 70.5 years) who survived 24 hours after repair of infrarenal ruptured AAA. Patients were resuscitated to standard parameters of perfusion (pulse, blood pressure, urine output, normal base deficit). MOD was determined based on six organ systems. Standard parametric (analysis of variance, t tests) and nonparametric (chi square, Wilcoxon) tests were used to compare hemodynamic data, red blood cell requirements, colon ischemia, and organ failure for patients with and without MOD. Results Patients who developed MOD had a significantly lower cardiac index and DO 2 for the first 12 hours; the difference was most significant at 8 hours. Logistic regression analysis demonstrated that the strongest predictors of MOD were DO 2 , early onset of renal failure, and total number of red blood cells transfused. Conclusions DO 2 is an earlier and better predictor of MOD after ruptured AAA than previously identified risk factors. Failure to achieve a normal DO 2 in the first 8 hours after repair is strongly associated with the development of MOD and a high mortality. Strategies to restore normal DO 2 may be useful to improve outcome in these high-risk patients.

To determine the relative efficacy of heat conservation and convective warming in maintaining perioperative normothermia, (central temperatureor = 36 degrees C).Thirty-seven patients undergoing elective gynaecological, orthopaedic, or general surgery scheduled to last two hours were prospectively studied. Patients were randomized to one of two groups. Group 1 patients received heat conservation with reflective blankets (Thermadrape, Vital Signs, Inc., Totowa, NJ) applied preoperatively and warmed i.v. fluids (Hotline SIMS Level I Technologies, Inc, Rockland, MA), Group 2 patients received convective warming (BairHugger, Augustine Medical Inc., Eden Prairie, MN) after induction of anaesthesia and i.v. fluids at room temperature. All patients received general anaesthesia with isoflurane. Tympanic membrane and forearm-fingertip skin temperature gradients were measured perioperatively at 15 min intervals.Central temperature decreased after induction to a minimum level of 35.9 +/- 0.1 degrees C in group 1 and 36.0 +/- 0.1 degrees C in group 2 and then increased towards pre-induction values in group 2, and were higher (P0.05) than in group 1: 95% group 2 patients had central temperatureor = 36.0 degrees C at the end of surgery (vs 69% of group 1, P0.05). During the first 30 min in PACU, central temperatures were higher in group 1 than in group 2 (36.8 +/- 0.1 degrees C vs 36.2 +/- 0.2 degrees C, P0.05). After 60 min, central temperatures were similar (36.8 degrees C). The incidence of shivering and degree of peripheral cutaneous vasoconstriction were also similar.Patients receiving convective warming were more likely to leave the operating room normothermic, and had higher central temperatures during the first 30 min in the recovery room. The intergroup temperature differences were small, and by 60 min, had disappeared.

To evaluate the tracheal intubating conditions and neuromuscular blocking characteristics of divided dose mivacurium or single dose rocuronium.Thirty-two patients undergoing elective surgery were studied. Anaesthesia was with propofol 2 mg.kg-1, followed by an infusion of 150 micrograms.kg-1.min.1. Patients were randomized to receive either mivacurium-0.15 mg.kg-1 followed 30 sec later by 0.1 mg.kg-1, or rocuronium- 0.9 mg.kg-1, followed 30 sec later by placebo. Tracheal intubating conditions were assessed 90 sec after the initial dose of relaxant by an anaesthetists who was unaware of patient group. The electromyographic (EMG) response of the first dorsal interosseus muscle to ulnar nerve train-of-four was measured.Successful tracheal intubation was performed in all patients after both mivacurium and rocuronium. Intubating conditions (jaw relaxation, open visible vocal cords) were judged to be good-excellent in all but one patient before insertion of the tracheal tube. However, patients receiving mivacurium were more likely to experience coughing and bucking after tracheal tube insertion (10/16 patients) than those receiving rocuronium (3/16 patients, P0.05). No patient in the rocuronium group experienced moderately vigorous coughing and bucking after insertion of the tracheal tube vs six patients in the mivacurium group (P0.05). Time to 10 and 25% recovery of neuromuscular function was faster (P0.05) after divided dose mivacurium (20 +/- 1 and 23 +/- 1 min, respectively) than after rocuronium (45 +/- 5 and 57 +/- 8 min, respectively).The results suggest that, during conditions of the study, divided dose mivacurium is not recommended for a 90-sec tracheal intubation in patients where moderate coughing and bucking is deemed unacceptable.

To compare the fluid warming capabilities of the Hotline and Flotem IIe devices in surgical patients, and whether warming intravenous (i.v.) fluids with the Hotline device resulted in less hypothermia and less need for other warming methods compared with the Flotem IIe device.Part 1. Prospective, nonrandomized. Part 2. Prospective, randomized.Teaching hospital, tertiary care center.Part 1. 24 adult patients undergoing elective surgery. Part 2. 49 adult patients scheduled for major elective orthopedic or gynecologic surgery of greater than 2 hours' duration with general anesthesia.Part 1. Insertion of sterile in-line thermistors along the path of fluids delivered using the Hotline or Flotem device. Part 2. Patients were randomly assigned to receive i.v. fluids via the Hotline (n = 21) or Flotem IIe (n = 18) warmers. Intervention for core hypothermia [lower esophageal temperature (Teso) less than 35.5 degrees C], was with forced air warming. Intervention for postoperative shivering was with meperidine by a nurse who was blinded to the treatment group.Part 1. Temperature of infused fluids before and after the warmer (T in and T out) and before the fluid entered the patient after insertion of a standard 84 cm extension set having a stopcock for injection of medications (T distal). Part 2. Tympanic (Ttym) was recorded before induction of anesthesia (baseline) and at 15-minute intervals after induction. Teso was recorded at 15-minute intervals after induction. The maximum intraoperative Ttym decline from baseline (delta Ttym max) was calculated.Part 1. Flow rates were between 1 and 33 ml/min. T out and T distal (mean +/- SEM) of fluids infused through the Hotline device were warmer compared with those infused via the Flotem IIe device (Hotline T out: 35.7 +/- 0.1 degrees C and Hotline T distal: 33.4 +/- 0.2 degrees C vs. Flotem IIe T out: 28.9 +/- 0.2 degrees C and Flotem IIe T distal: 28.3 +/- 0.2 degrees C; p0.001 between warmers). Part 2. Maximal decrease in Ttym from preoperative baseline (before intervention) was greater in the Flotem IIe compared with the Hotline group (delta Ttym max = -1.4 +/- 0.1 vs. -0.9 +/- 0.1 degree C, p = 0.01). Five patients in the Flotem IIe group required forced air warming for treatment of hypothermia versus none in the Hotline group (p0.01). Postoperatively, five patients in the Flotem IIe group required treatment with meperidine for severe shivering versus one patient in the Hotline group (p0.05).The Hotline device delivered fluids to the patient at consistently warmer temperatures compared with the Flotem IIe device during actual clinical conditions. This was associated with maintenance of near normal core temperatures throughout the procedure in the Hotline group, and a decreased need for interventions such as forced-air warming and treatment for severe shivering.

To determine the influence of anesthetic technique and primary drug on operating room (OR) exit time (time between end of surgery until time patient exists the OR) after addition of desflurane to the hospital formulary.Prospective study.Ambulatory surgery unit of a university hospital.1,568 outpatients requiring anesthesia.Addition of desflurane to the hospital formulary, and substitution of desflurane vaporizers for enflurane vaporizers in the ambulatory surgery unit.The following information was recorded for all anesthetic encounters over a six-month time interval: demographics, duration of surgery, primary anesthetic technique, primary anesthetic drug, and exit times. General anesthesia was used in 907 patients [desflurane: 209 patients, isoflurane: 429 patients, halothane: 192 patients, propofol: 72 patients, other intravenous (i.v.): 5 patients], major conduction anesthesia (spinal and epidural) in 43 patients, peripheral nerve blocks in 90 patients, and i.v. sedation in 528 patients. The exit time was significantly greater (0.05) in patients who received general anesthesia (mean +/- SEM 14 +/- 0.2 min) compared with spinal/epidural (8 +/- 0.7 min), nerve blocks (8 +/- 0.4 min) and i.v. sedation (7 +/- 0.2 min). Exit times were longer in older patients receiving general anesthesia (exit time = 12.3 + 0.04 x age, SE = 6.7 min, p0.0009), whereas exit times were shorter in older individuals receiving i.v. sedation (exit time = 8.97 - 0.038 x age, SE = 3.6 min, p0.0001). For patients receiving i.v. sedation, exit times were shorter as duration of surgery increased (exit time = 7.86 - 0.015 x duration of surgery, SE = 3.6 min, p0.0002). Primary anesthetic drug did not affect exit times.Regional anesthesia and i.v. sedation were associated with faster OR exit times compared with general anesthesia. Despite desflurane's shorter elimination kinetics and recovery characteristics, use of this drug did not result in shorter exit times.

The study evaluated the warming ability and flow rates associated with four fluid warming devices during pressure driven infusion and during wide open gravity driven roller clamp infusion. Warmers tested were the Astotherm, Flotem IIe, Level 1 System 250 and a modified cardioplegia heat exchanger. Fluids tested were crystalloid, red cells diluted with 200 ml, 0.9% saline, and undiluted red cells. The volume of fluid and outlet temperatures (point where i.v. tubing would be attached to the patient) were measured for each fluid and compared among warmers for each flow rate condition. For pressure driven infusion of red cells and crystalloid, the System 250, and modified heat exchanger delivered warmer fluids (33-35 degrees C) at higher flow rates (160-740 ml.min-1) than the Astotherm and Flotem (23-31 degrees C, 44-268 ml.min-1, P0.05). For gravity driven infusion, the System 250 delivered the warmest fluids (33-36 degrees C, P0.05) compared with the modified heat exchanger (29-35 degrees C), Astotherm (26-32 degrees C) and Flotem (26-27 degrees C). In conclusion, the modified heat exchanger and System 250 were moderately effective (outlet temperature32 degrees C) in warming crystalloid and red cells at pressure driven flow rates. Only the System 250 warmed red cells35 degrees C at gravity driven flow rates. The Flotem and Astotherm were not effective in warming rapidly infused solutions. None of the warmers tested was able to deliver fluids at normothermia (36.5 degrees C).

The purpose of the study was to compare the relative effectiveness of several combinations of tapes and taping methods with respect to the force required to pull out intravenous catheters. A simulated forearm model consisting of a section of firm PVC pipe was used for the first and second series of experiments. In the third experiment, one method of taping catheters was compared in the PVC model and in volunteers. Pull-out forces were measured with a force transducer and recorded on paper. In the first experiment, catheters secured with Curity tape resisted pullout to a greater extent than those with Transpore tape and provided approximately twice the force advantage (P < 0.05). In the second experiment using Curity tape, minimum forces to dislodge the catheters were (means ± SD) 53 ± 13, 82 ± 13, 113 ± 29, 124 ± 24, 176 ± 29 and 141 ± 46 N, for methods 1–6, respectively. In the third series, the minimum pullout forces were higher for Curity than with Transpore tape for both the human and simulated PVC forearm surfaces (63 ± 11 and 55 ± 12 N vs 52 ± 7 and 44 ± 12 N, P < 0.01), and the pullout forces were higher for the simulated vs the human skin surface for both tape types (P < 0.01). Compared with Curity tape, Transpore tape was more likely to fail by tape fracture in both the simulated and human skin surfaces (P < 0.05). The data suggest that there are important differences in pullout forces and mechanisms of dislodgement depending on taping method and tape type. Curity tape, using method 5 or 6, was superior to Transpore tape and the other taping methods in resisting pullout.

diagnosis 25.8 days (range 1–63, s.d. 13.2). By end of year 1, 30% grew Pseudomonas (inc aeruginosa), 36% had abnormal chest x-rays, 27% required IV antibiotics. No correlation between number of contacts with the team and abnormal x-ray, need for intravenous antibiotics, psychosocial issues or positive respiratory (lavage & cough swab) samples in year 1. Children with pancreatic insufficiency had more contacts with the nurse in the year following diagnosis (16 contacts more, 95%CI 4.6–27.3, p = 0.007) than children who were pancreatic sufficient. Per additional week of oral antibiotics, children had 0.7 more contacts (95%CI 0.1 to 1.3, p = 0.025). When both variables were taken into account, pancreatic insufficiency and an additional week of oral antibiotics were associated with 14.5 more contacts (95%CI 3.7–25.4, p = 0.01) and 0.6 more contacts (95%CI 0.04–1.1, p = 0.04) respectively. Conclusion: Data shows more communication with parents whose children are pancreatic insufficient and need more oral antibiotics. It is unclear whether this reflects increased clinical need or parental anxiety. Screening has revolutionised CF care and we employ a policy of frequent contact & support responsive to parental needs.

The study evaluated the effects of different techniques used to secure intravenous (i.v.) catheters. An angiocatheter attached to standard i.v. tubing was taped to human forearm using a standard taping method. A calibrated piezoelectric force transducer was attached to the i.v. tubing. The force applied along the longitudinal axis to pull out the taped catheter was measured and recorded on paper. Three tape types, Curity, Leukopor and Transpore, were evaluated alone, with benzoin skin pretreatment and with mastisol pretreatment. A randomized 3 x 3 block design with 20 replications per block was utilized, and a total of 180 pullout tests were performed on two adult volunteers. Without pretreatment, the forces required to dislodge catheters were (means +/- SEM) 46 +/- 2, 37 +/- 2 and 38 +/- 2 Newtons for Curity, Leukopor and Transpore tape, respectively. Corresponding values for mastisol pretreatment (64 +/- 1, 64 +/- 3 and 52 +/- 3 Newtons) were greater (P0.05) for each tape compared with benzoin (54 +/- 3, 53 +/- 2 and 40 +/- 2 Newtons) and no pretreatment. The most frequent failure mode for Transpore tape was by tape fracture, for Curity tape was by separation from the skin of tape and catheter as a single unit, and for Leukopor tape was by catheter separation while tape remained attached to skin (P0.001). The data suggest that the application of mastisol prior to taping i.v. catheters with Curity or Leukopor tape helps to minimize the risk of accidental dislodgement.

The purpose of the study was to determine the effect of nondepolarizing muscle relaxants and waiting time on muscle fasciculations after succinylcholine in anaesthetized patients. Adult men and women, 60-80 kg, received pretreatment doses of atracurium 5 mg (n = 160), pancuronium 1 mg (n = 123), d-tubocurarine 3 mg (n = 97), or vecuronium 1 mg (n = 62). Waiting times between pretreatment and succinylcholine, 100 mg, ranged between 0.6 and 5 min. Data points (presence or absence of fasciculations and waiting time) were entered for each patient. Waiting time response curves were obtained between the logit transformation of the probability of no fasciculations and the log waiting time for each drug. Statistical differences between wait time response curves were determined by non-overlapping of the associated 95% confidence intervals. The frequency of muscle fasciculations was reduced with increased waiting time for all nondepolarizers tested. Following wait times of three, four and five minutes, the probability of not fasciculating was greatest with d-tubocurarine (90, 97 and 99%, respectively) and atracurium (89, 93 and 96%). Corresponding values for pancuronium were 70, 82 and 88% and for vecuronium were 74, 82 and 86%. Waiting times to prevent fasciculations in 80% and 90% of patients were shorter with d-tubocurarine (2.46 and 3.02 min, respectively) or atracurium (2.16 and 3.24 min) than pancuronium (3.77 and 5.35 min) or vecuronium (3.73 and 6.36 min).(ABSTRACT TRUNCATED AT 250 WORDS)

Dye dilution curves have been used to calculate cardiac output under conditions of normal circulation. Unfortunately, these curves cannot be integrated easily to determine cardiac output under the low flow states of CPR. The time to initial dye appearance (circulation time), may be useful in judging relative changes in flow when studying experimental resuscitation techniques. The purpose of this study was to investigate the relationship between dye circulation times and other hemodynamic measures during CPR. Repeated measurements of coronary perfusion pressure, dye circulation times, blood gases, and end-tidal CO2 (ETCO2) were made in dogs undergoing CPR. Dye circulation time was significantly associated with the systolic, diastolic, and coronary perfusion pressures. The correlation between circulation time and ETCO2 was -0.70 (P less than 0.0001). There was no correlation with the arterial-venous PO2 gradient. There were significant correlations between the circulation time and both the A-V PCO2 and the A-V pH gradients. We conclude that dye circulation times may be used to gauge relative changes in blood flow during CPR, particularly in laboratory investigations involving repeated measurements.

Background The purpose of this study was to evaluate the efficacy of an experimental approach to forced air warming using hospital blankets or a Bair Hugger warming unit (Augustine Medical Inc., Eden Prairie, MN) to create a tent of warm air. Methods Adult patients undergoing major surgery were studied. Patients were randomized to receive forced air warming using either a commercial Bair Hugger blanket (control group, n = 44; set point, 43 degrees C) or standard hospital blankets (experimental group, n = 39; set point, 38 degrees C). Distal esophageal temperatures were monitored. Patients were contacted the following day regarding any problems with the assigned warming technique. Results Surface area covered was 36 +/- 12% (mean +/- SD) in the experimental group and 40 +/- 10% in the control group. Final temperatures at the end of surgery were similar between groups: experimental, 36.2 +/- 0.6 degrees C; control, 36.4 +/- 0.7 degrees C. A similar number of patients had esophageal temperature less than 36 degrees C at the end of surgery in both groups (experimental, 12 of 39 [31%]; control, 12 of 44 [27%]). The majority of patients were satisfied with their anesthetic and warming technique: experimental, 38 of 39 patients; control, 44 of 44 patients. There were no thermal injuries. Conclusions Standard hospital blankets heated to 38 degrees C forced air were equally as effective as commercial blankets heated with forced air at 43 degrees C. However, based on concerns expressed by the manufacturer, this experimental technique should not be used until further safety evaluation has been undertaken.

Objective: To evaluate the cardiovascular effects of a propofol-ketamine combination in patients undergoing coronary artery surgery. Design: Prospective, randomized study. Setting: Tertiary care teaching hospital, single center. Participants: Seventy-eight adult patients. Interventions: Patients were randomly allocated to receive propofol-ketamine for induction and maintenance of anesthesia (n = 36) or fentanyl-enflurane (controls, n = 42). Measurements and Main Results: Hemodynamics and other variables were recorded during and after surgery and for 24 hours in the intensive care unit. Before cardiopulmonary bypass (CPB), there was similar incidence of treatment for hypotension (42% of patients in both groups), tachycardia (propofol-ketamine, 6%; controls, 5%), and myocardial ischemia (propofol-ketamine, 3%; controls, 12%). In the propofol-ketamine group, there was a decreased requirement for inotropic agents after CPB (22% of patients) compared with controls (49% of patients; p = 0.02). There was a reduced incidence of myocardial infarctions (creatine kinase myocardial band > 133 U/L) in the propofol-ketamine group compared with the control group (0% v 14%; p = 0.02; Fisher's exact test). Patients in the propofol-ketamine group were more likely to have their tracheas extubated within 8 hours of arrival in the intensive care unit compared with controls (33% v 7%; p = 0.01; Cochran-Mantel-Haenzel test). Conclusions: The propofol-ketamine combination was associated with a similar incidence of pre-CPB hypotension and ischemia, a decreased need for inotropes after CPB, an earlier time to tracheal extubation, and a reduced incidence of myocardial infarctions compared with controls. Copyright © 2000 by W.B. Saunders Company

The Thermostat device (Aquarius Medical Corp., Phoenix, AZ) is used in a new technique to accelerate recovery from hypothermia by mechanically distending blood vessels in the hand, thereby increasing transfer of exogenous heat to the body core. We evaluated the use of the Thermostat device in patients with mild postoperative hypothermia (36 degrees C). We studied adult patients undergoing elective surgery, general anesthesia, and neuromuscular blockade. Patients with an initial postoperative tympanic membrane temperature36 degrees C were randomized into two groups: 1) Thermostat, which consisted of a hypothermia warming mitt/seal and thermal exchange chamber for 60 min, and 2) conventional treatment, which consisted of warm blankets and/or radiant heat. Of the 191 patients enrolled, 60 (31%) developed hypothermia and were randomized to receive the Thermostat (n = 30) or conventional methods (n = 30). Fourteen patients in the Thermostat group and 17 patients in the conventional group rewarmed to 36 degrees C before discharge from the recovery room (P is not significant). There were no differences in vital signs, rewarming time, time to discharge from the recovery room, or postoperative temperature between groups. We conclude that patients with mild postoperative hypothermia rewarmed in a similar fashion, regardless of whether the Thermostat or conventional methods were used.We found that a commercially available negative pressure rewarming device (Thermostat; Aquarius Medical Corp., Phoenix, AZ) was not effective in accelerating rewarming in postoperative hypothermic surgical patients after general anesthesia.

The WuScope is a rigid, fiberoptic laryngoscope designed to facilitate tracheal intubation without the need for head extension. The study evaluated the WuScope in anesthetized patients with neck immobilization.Patients were randomized to one of two groups: those receiving fiberoptic laryngoscopy (WuScope, n = 43) and those receiving conventional laryngoscopy (Macintosh blade, n = 44). Manual in-line stablization of the cervical spine was done during intubation. Seven parameters of intubation difficulty were measured (providing an intubation difficulty scale score): number of operators, number of attempts, number of techniques, Cormack view, lifting force, laryngeal pressure, and vocal cord position.Successful intubation occurred in 95% of patients in the fiberoptic group and in 93% of patients in the conventional group. There were no differences in number of attempts. In the fiberoptic group, 79% of patients had an intubation difficulty scale score of 0, representing an ideal intubation: that is, one performed by the first operator on the first attempt using the first technique with full glottic visualization. Only 18% of patients in the conventional group had an intubation difficulty scale score of 0 (P0.001). More patients had Cormack grade 3 or 4 views with conventional than with fiberoptic laryngoscopy (39 vs. 2%, P0.001). Intubation times in patients with one attempt were slightly longer in the fiberoptic (median, 25th-75th percentiles: 30, 23-53 s) compared with the conventional group (24, 17-30 s, P0.05). Corresponding times in patients requiringone attempt were 155 (range, 112-201) s and 141 (range, 95-186) s in the fiberoptic and conventional groups, respectively (P value not significant).Compared with conventional laryngoscopy, tracheal intubation using the fiberoptic laryngoscope was associated with lower intubation difficulty scale scores and better views of the laryngeal aperture in patients with cervical imnmobilization. However, there were no differences in success rates or number of intubation attempts.

To evaluate tapes and taping methods with respect to the minimum force required to dislodge endotracheal tubes (ETTs).A simulated face model consisting of a section of PVC pipe was used. The ETT was attached to a piezo-electric force transducer and pullout force was manually applied in a vertical, right or left direction. Five tape types were tested: Curity, Leukosilk, Hy.tape, Leukopore, and Transpore, Seven taping methods were used to secure the ETT. The methods differed with respect to tape width and whether the tape was split along its longitudinal axis. Each taping condition was replicated 20 times (7 methods x 5 tapes x 3 directions) for a total of 2100 pullout tests.Minimum forces to dislodge ETTs were higher (P0.05) with Curity tape (mean +/- SD; 135 +/- 75 N) than with the other tapes (Leukosilk: 93 +/- 51 N, Hy.tape: 78 +/- 34 N, Leukopore: 47 +/- 32, and Transpore: 37 +/- 23 N). The most secure taping method was achieved by taping the ETT, using 2.5 cm wide Curity tape, in a circumferential fashion to both the upper and lower borders of the simulated mouth opening, and reinforcing these tapes with two strips applied longitudinally across the borders of the mouth opening (method 7). Taping methods which involved splitting the tape along its longitudinal axis resulted in lower minimal pullout forces whenever the pullout force was directed towards the side of attachment (P0.05 vs right and vertical direction).There are differences in ETT pullout forces and mechanisms of dislodgement depending on taping method and tape type.

The purpose of the study was to evaluate the ability of five commercially available devices utilizing a variety of heat exchange technologies to deliver normothermic (37 degrees C) fluids. Conditions of slow (6.5 mL/ min), moderate (13-25 mL/min), and rapid (gravity and pressure driven flows, roller clamp wide open) infusion were simulated. Fluid temperatures were measured using rapid response thermistors after the fluid exited the heat exchanger (T outlet) and before delivery to the patient intravenously (IV) (T distal). Devices tested were the FW537, H1000, Hotline, BairHugger, and Flotem IIe. Fluids tested were crystalloid at room temperature and red cells diluted with saline (11-19 degrees C). At slow and moderate flows, T distal of crystalloid was between 35.3 and 37.9 degrees C for Hotline at 42 degrees C, 33.8 and 37.7 degrees C for H1000 at 42 degrees C, 29.4 and 34.2 degrees C for BairHugger, 26.1 and 31.5 for Flotem IIe, and 23.8 and 32.1 for FW537 at 42 degrees C. With gravity and pressure driven flows, T distal of crystalloid were 39.0 and 38.9 for H1000 at 42 degrees C, 38.7 and 38.4 degrees C for FW537 at 42 degrees C, 34.7 and 28.9 degrees C for Hotline at 42 degrees C, 29.2 and 24.2 degrees C for BairHugger, and 29.7 and 24.2 degrees C for Flotem. In conclusion, only the H1000 at 42 degrees C was effective at delivering normothermic fluids at all clinically relevant flow rates. The Hotline at 42 degrees C was effective at slow and moderate flow, whereas the FW537 was effective only at rapid flow.

Study objective Concerns exist about the effect of flexible fiberoptic bronchoscopy (FFB) on intracranial pressure (ICP). We studied the effect of FFB on cerebral hemodynamics in patients with severe head injury. Design Prior to FFB, patients were anesthetized and muscle relaxants were given as necessary to eliminate coughing. Comparisons were made of mean arterial pressure (MAP), ICP, and cerebral perfusion pressure (CPP) prior to, during, and after FFB, as well as comparisons of mean cerebral hemodynamic values in an 8-hour period before and after FFB. Observations were made of changes in neurologic status post-FFB. Setting Surgical intensive care unit of Level 1 Trauma Center. Patient population Fifteen patients with severe head injury in whom ICP was monitored and who required FFB for diagnosis of nosocomial pneumonia or treatment of lobar collapse. Results Pre-FFB ICP averaged 14.3 mm Hg (range, 6 to 26 mm Hg). During FFB, patients experienced a mean increase in ICP of 13.5 mm Hg above basal values (p=0.0001). At peak ICP, MAP increased from a baseline of 92.3 mm Hg (SD±16.1) to 111.5 mm Hg (±13.9). Mean CPP was 83.7 mm Hg at peak ICP (range, 52 to 121 mm Hg), a 14.0% increase over baseline. The ICP and MAP returned to basal levels following bronchoscopy. No patient had a clinically significant increase in ICP or demonstrated any deterioration in Glasgow Coma Scale score or neurologic examination findings post-FFB. Conclusions Although FFB causes an increase in ICP in patients with severe head injury, MAP also rises, and an adequate CPP is maintained. The ICP returns to basal levels after the procedure. When properly performed, FFB does not adversely affect neurologic status in patients with severe head injury.

Previous investigations have shown that peripheral injection of medication during cardiac arrest leads to prolonged circulation times and low peak drug levels. Current Advanced Cardiac Life Support guidelines suggest that administering a bolus of flush solution after injection of medication may hasten drug delivery, but there is little evidence to support this. The purpose of this study is to investigate the effect of peripheral bolus injection on circulation times during cardiac arrest. Measurements of circulation times were made following injection of indocyanine green dye both with and without a bolus of 20 mL saline flush into a peripheral vein of mongrel dogs. There was no difference in systolic, diastolic, or coronary perfusion pressures during the injections with or without bolus injection. Similarly, there was no difference in end-tidal CO2 or in arterial-venous PO2, PCO2, or pH gradient. The circulation time without bolus injection was 77.7 +/- 42.7 seconds while circulation time with the saline flush was 48.3 +/- 20.9 seconds (P less than .001). Peak dye concentration without saline flush was 3.0 +/- 1.0 mg/L, and peak dye concentration with saline flush was 3.8 +/- 0.9 mg/L (P less than .001). We conclude that a bolus injection of 20 mL of saline enhances dye circulation times and peak levels during cardiac arrest in this animal model. The clinical application of this technique warrants further investigation.

Background The WuScope is a rigid, fiberoptic laryngoscope designed to facilitate tracheal intubation without the need for head extension. The study evaluated the WuScope in anesthetized patients with neck immobilization. Methods Patients were randomized to one of two groups: those receiving fiberoptic laryngoscopy (WuScope, n = 43) and those receiving conventional laryngoscopy (Macintosh blade, n = 44). Manual in-line stablization of the cervical spine was done during intubation. Seven parameters of intubation difficulty were measured (providing an intubation difficulty scale score): number of operators, number of attempts, number of techniques, Cormack view, lifting force, laryngeal pressure, and vocal cord position. Results Successful intubation occurred in 95% of patients in the fiberoptic group and in 93% of patients in the conventional group. There were no differences in number of attempts. In the fiberoptic group, 79% of patients had an intubation difficulty scale score of 0, representing an ideal intubation: that is, one performed by the first operator on the first attempt using the first technique with full glottic visualization. Only 18% of patients in the conventional group had an intubation difficulty scale score of 0 (P < 0.001). More patients had Cormack grade 3 or 4 views with conventional than with fiberoptic laryngoscopy (39 vs. 2%, P < 0.001). Intubation times in patients with one attempt were slightly longer in the fiberoptic (median, 25th-75th percentiles: 30, 23-53 s) compared with the conventional group (24, 17-30 s, P < 0.05). Corresponding times in patients requiring > one attempt were 155 (range, 112-201) s and 141 (range, 95-186) s in the fiberoptic and conventional groups, respectively (P value not significant). Conclusions Compared with conventional laryngoscopy, tracheal intubation using the fiberoptic laryngoscope was associated with lower intubation difficulty scale scores and better views of the laryngeal aperture in patients with cervical imnmobilization. However, there were no differences in success rates or number of intubation attempts.

During CPR, the dynamics of the chest compression process play a major role in determining the outcome of the resuscitation effort. To quantify chest wall motion during CPR, a number of important variables must be determined, including maximum downward acceleration and velocity of the chest wall, time during which the wall is held in compression, and maximum depth and rate of chest compression. In this study, miniature accelerometers were used to record chest wall motion during simulated CPR with standard training manikins. One series of CPR tests included force measurements from a three-dimensional force platform placed under the manikin. The results of this investigation showed that American Heart Association (AHA)-certified rescuers are able to produce a consistent pattern of chest wall displacement during a manikin training exercise, and only small differences in displacement recordings are found when comparing one certified rescuer to another. Any given rescuer will usually generate a consistently repeatable acceleration pattern during CPR. However, these cyclical acceleration patterns differ markedly when comparing different certified rescuers. Mechanical CPR with a standard device produced larger peak accelerations than manual CPR. However, the maximum downward velocity was usually higher with manual CPR. In comparison with trained but clinically inexperienced individuals, rescuers with extensive in hospital experience produced relatively larger downward accelerations, longer "hold" times with the chest in compression, and maximum chest displacements that exceeded the current AHA recommendations. Measurements of the force transmitted through the manikin to a force platform clearly indicated the presence of a "hold" phase (if present) and the existence of large force components in the horizontal plane.

Flow visualization studies were conducted in a water-Plexiglas tube model which simulated flow conditions commonly encountered in major vessels. Complex secondary flow patterns in the main line downstream of a branching vessel were observed in found to be relatively independent of the diameter ratio and angle of departure of the branching tube. The ratio of branching to total flow was the prinicipal determinant of the aforementioned secondary flows. Venous and arterial branching markedly differed. Arterial-type flows produced a pair of vortex sinks downstream of the branching port. These vortex-sink flow fields, which previously have not been reported, captured fluid particles already downstream of the branching orifice and returned these particles upstream to exit via the branching tube. In a region very close to the tube wall, streamlines were also observed moving upstream to be captured by the branching vessel. The interaction of this local upstream flow with the general downstream flow produced a pair of stagnation points located downstream and lateral to the branching orifice. These stagnation regions are discussed in relation to atheroma and thrombus formation.

Avalanche data were obtained by direct observation of the Vaughan Lewis Icefall. Magnitude, time and location of each ice fall were recorded and the resulting data were analyzed statistically. An inverse relationship was found between the relative frequency and the magnitude of the avalanches. A significant diurnal variation in avalanche rate was also detected. During the early morning hours the avalanche rate reached a maximum. No secondary increase in the avalanche frequency was observed during the evening cooling period. The data indicated that a given ice fall results in an increased probability of an ice fall occurring shortly thereafter. After approximately 4 min the effect of a given avalanche no longer correlates with succeeding avalanches.

This paper deals with some experiments conducted with low-temperature seeded plasmas at atmospheric pressure. Results of the experiments indicated two modes of steady, stable current conduction between the electrodes. A thermionic process was found to be the mechanism for current emission under all conditions and the effects of potassium adsorption on electrode surfaces was found to be important. A quantitative comparison between the observed voltage-current characteristics and two current conduction theories is presented. This comparison indicated that both Joule heating and nonequilibrium heating of electrons must be considered in understanding the current conduction phenomena. Electrode heat transfer was also studied and analysis of the data indicated that an important heat transfer mechanism was the penetration of the surface work function barrier as electrons entered or left the surface.

Design details of a portable, light-weight, seismic recording system are presented together with data concerning sensitivity and frequency response. Field procedures and methods are described with emphasis on coupling the hydrophone detector to waves propagating in the glacier ice. Two of the field-recorded signals are reproduced here: the first resulted from a small serac avalanche in the ice fall and the second was produced by an unusual, local source of glacier noise.

With the addition of appropriate logic circuitry and a single-board microcomputer, a thermistor flowmeter becomes a clinically useful ventilation monitor. The microcomputer calculates upper and lower reference (voltage) levels from the baseline (normal) flow signal generated by the thermistor bridge. If the flow signal fails to pass repetitively through one or both of these reference levels, visual and audio alarms are generated. Tests performed with both high-frequency (3 Hz) and low-frequency (0.2 Hz) ventilator systems show the usefulness of this system in sensing a variety of malfunctions, including endotracheal tube occlusions, leaks, changes in flow or tidal volume, and hose disconnects.

A conventional, low-frequency ventilator was modified to ventilate dogs at high frequencies of 85 to 185 cycle/min while cardiovascular and pulmonary variables were monitored. Although gas transport was adequate, cardiac output was diminished when compared to low-frequency ventilation. The addition of an in-line pneumotachograph markedly increased PaCO2 during high-frequency ventilation. Carbon dioxide transport was primarily dependent upon the magnitude of the tidal volume at all high frequencies tested.