Fentanyl sequestration in lungs during cardiopulmonary bypass.

Serum fentanyl concentrations were measured before, during, and after cardiopulmonary bypass and correlated with changes in total protein, albumin, hematocrit, pH, and PCO2 in five patients undergoing cardiac surgery. Serum fentanyl concentrations, total protein, albumin, and hematocrit declined with initiation of bypass but remained unchanged thereafter. PCO2 and pH did not change. In an additional seven patients, simultaneous pulmonary-artery and radial-artery fentanyl concentrations were measured. During bypass, when little, if any blood flowed through the pulmonary circulation, pulmonary artery fentanyl concentrations were higher than systemic arterial concentrations, but when lung ventilation and perfusion were restored, radial artery concentrations rose and pulmonary artery concentrations fell, indicating fentanyl sequestration in the lungs during bypass.

Doxepin effects on chronic pain, depression and plasma opioids.

Thirty patients with chronic low back or cervical pain combined with clinical depression were studied in a six-week, randomized, double-blind comparison of doxepin and placebo. Dependent variables included Hamilton Depression Scores, the Clinical Global Assessment Scale, and Profile of Mood States (POMS), and subjective ratings (visual analogue scales) of pain severity, percent of time pain felt, and effect of pain on activity, muscle tension, sleep, mood, and analgesic drug consumption. Plasma levels of doxepin, desmethyldoxepin, beta-endorphin, and enkephalin-like activity were also measured. Significant improvements in the doxepin-treated group compared to the placebo group were seen in Hamilton scores, Global Assessment Scale, Profile of Mood States, percent of time pain felt, and effect of pain on sleep, muscle tension, and mood. Some improvement was observed after 1 week, although most improvement occurred at 6 weeks, when the mean doxepin dose was 2.5 mg/kg and plasma doxepin and desmethyldoxepin averaged 70 ng/ml. Nonspecific enkephalin-like activity (but not beta-endorphins) increased for the treatment group and decreased for the placebo group. The efficacy of doxepin compared with that of placebo was thus documented in several depressive and pain parameters, indicating that doxepin is a valuable treatment for patients with chronic pain and depression.

Doxepin's effects on chronic pain and depression: a controlled study.

Sixty patients with chronic pain of the low back or cervical spine concomitant with clinical depression were studied in a 6-week, randomized, double-blind comparison of doxepin and placebo. Significant improvements in the doxepin-treated group compared to placebo or to baseline values were seen on Hamilton depression scores, Global Assessment Scale scores, pain severity, percent of time pain felt, and effect of pain on activity, sleep, and muscle tension. Some improvements were observed after 1 week of treatment; the most improvement occurred at 6 weeks, when the mean doxepin dosage was approximately 200 mg/day and plasma doxepin and nordoxepin averaged 80 ng/ml. No significant harmful effects were observed. Neither plasma beta-endorphin nor enkephalin-like activity demonstrated significant differences from baseline. These data indicate that doxepin is a valuable treatment for patients with chronic pain and depression.

Acute effects of dobutamine and isoproterenol after implantation of a total artificial heart.

The hemodynamic effects of dobutamine and isoproterenol infusions were studied in five Holstein calves 1 day before and 2 days after the implantation of a Jarvik-7 total artificial heart (TAH). Cardiac output was decreased, and systemic vascular resistance (SVR) and pulmonary vascular resistance were increased after TAH implantation. Administration of dobutamine before TAH implantation caused an increase in heart rate, and discontinuation of dobutamine decreased cardiac output. Administration of dobutamine after TAH implantation caused decreases in mean arterial pressure and SVR. Isoproterenol increased heart rate and cardiac output and decreased SVR before TAH implantation. Isoproterenol produced no significant hemodynamic effects after TAH implantation. These results describe the hemodynamic effects that could be expected from normal clinical infusions of these drugs in the patient who is supported by the TAH as a bridge to heart transplantation; these results are of additional interest in that they describe the peripheral effects of the two agents independent of cardiac effects.

The cardiac donor: a six-year experience.

From March 1, 1979, to March 1, 1985, the University of Arizona received 223 cardiac donor referrals. Sixty-two were accepted: 15 local, 23 regional (less than 370 km or 200 nautical miles), and 24 distant (370 to 1556 km or 200 to 840 nautical miles). Thirty-eight donor deaths were due to motor vehicle accidents, 10 to gunshot wounds, 6 to cerebral disease, and 8 to other closed-head lesions. The mean time from injury to brain death was 65 +/- 5 hours (+/- standard error of the mean [SEM]) and from brain death to organ donation, 12 +/- 3 hours. The mean ischemic time for the donor hearts ranged from 30 to 233 minutes (mean +/- SEM, 128 +/- 7 minutes). Fifty patients, otherwise acceptable, were refused as cardiac donors because an ABO-compatible recipient was not available. Two regionally procured hearts failed at operation, 1 because of unrecognized donor sepsis and 1 from a patient on large-dose inotropic support. Although there was no difference in myocardial function, median survival with follow-up through June 30, 1985, of patients receiving locally, regionally, and distantly procured organs was 59 months, 18 months, and 21 months, respectively. Cumulative proportion 1-year survival was 93%, 56%, and 61%, respectively. The 2-year survival was 85% for patients given locally procured hearts, 43% for those with regionally procured hearts, and 38% for those with a heart from a distant donor. Survival curves showed significantly longer survival for locally procured organs than regionally or distantly procured organs (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Priming and recognition in ECT-induced amnesia.

Priming and recognition were tested in patients receiving electroconvulsive therapy (ECT) for treatment of a psychiatric disorder. Patients studied a list of words just prior to ECT and then received memory tests for those words after recovering from ECT. Stem-cued recall was poor (retrograde amnesia), but priming on word-stem completion was preserved. Recognition was poor on a "high-criterion" test requiring a retrieval-based judgment but partially intact on a "low-criterion" test requiring a familiarity-based judgment. The results support the familiarity-retrieval distinction in two-component theories of recognition and suggest that signal detection measures of sensitivity are not wholly independent of response criteria.

Characterization of alpha-adrenoceptor activity in the preterm piglet mesentery.

To characterize neonatal mesenteric alpha-adrenoceptor populations, an extracorporeal perfusion circuit was established to control intestinal blood flow in prematurely delivered (by cesarean section at 90% of gestational age) piglets. Activation of alpha 1-adrenoceptors was documented by observing dose-dependent increases in mesenteric perfusion pressure after intramesenteric arterial injection of methoxamine; alpha 2-adrenoceptor activity was confirmed by finding similar increases in mesenteric perfusion pressure after intramesenteric arterial injections of BHT 933. Peripheral intravenous injections of WB 4101 (a competitive alpha 1A-adrenoceptor antagonist), but not clorethylclonidine (CEC, an alpha 1B-adrenoceptor antagonist), significantly blunted (P < .05, ANOVA) the mesenteric vasoconstrictor responses to methoxamine. The mesenteric vasoconstrictor response to BHT 933 (an alpha 2-adrenoceptor agonist) also was blunted by WB 4101, but not by CEC. These data suggest that alpha 1A- and alpha 2-adrenoceptors can be activated in the small intestinal mesentery of piglets well before they reach full-term maturation, although receptor specificity has not been fully established.

Asymptomatic undetected mediastinal mass: a death during ambulatory anesthesia.

T-cell lymphoma is the fastest growing non-Hodgkin's lymphoma occurring in children. Its clinical presentation is frequently abrupt, and total tumor mass can double every few days. At the same time, the number of ambulatory anesthesia procedures for children is increasing at a rapid rate. Anesthesiologists are constantly faced with decisions regarding the adequacy of available preoperative information. What information do we need, and how recent should it be? This case shows that recent diagnostic imaging studies not showing the presence of a mediastinal lymphoma can be misleading. It provides a strong warning to all anesthesiogists involved in ambulatory anesthesia.

Anesthesia for otolaryngologic surgery involving use of a laser.

Many additional considerations go into the anesthetic management of an otolaryngologic case involving laser surgery. All these considerations involve techniques for facilitating cooperation between the anesthesiologist and the surgeon, while at the same time doing what's best for the patient. The additional risk of fire and inadvertent injury to either the patient or medical personnel should receive high-priority attention by both the surgeon and the anesthesiologist. In short, "vigilance" takes on additional and special meanings when a laser is in use.

Comparative myocardial depressive effects of propofol and thiopental.

To compare the direct myocardial effects of thiopental and propofol, concentration-contractility curves were determined by using an isolated guinea pig left atrial preparation. Contractility was measured as peak twitch tension, maximum rate of contraction (dT/dt), and maximum rate of relaxation (-dT/dt). Drug concentrations ranged from 56 microM (10 micrograms/mL) to 2800 microM (500 micrograms/mL) propofol and 3.8 microM (1 microgram/mL) to 190 microM (50 micrograms/mL) thiopental. Data were fitted to a sigmoidal inhibitory pharmacodynamic model in which an increasing incremental drug concentration is needed to cause a consistent incremental effect. Comparisons were then made of the drug concentrations at which a 50% inhibition in contractility was noted (IC50). To compare drugs on an equi-anesthetic basis, comparisons also were made between IC50 values normalized to anesthetic concentrations needed to produce anesthesia (67.8 microM and 28.1 microM for thiopental and propofol, respectively). Data from seven atrial preparations for thiopental and seven atrial preparations for propofol were analyzed. The IC50 (microM) for peak twitch tension were 20.9 +/- 6.3 and 96.6 +/- 10.1 (P < 0.05), for dT/dt were 21.1 +/- 5.9 and 86.9 +/- 8.3 (P < 0.05), and for -dT/dt were 21.0 +/- 6.1 and 84.3 +/- 9.2 (P < 0.05) for thiopental and propofol, respectively. When the normalized IC50 were compared, the differences between anesthetics became greater. For guinea pig left atria in vitro, thiopental is a more potent myocardial depressant than propofol, especially when compared relative to anesthetic potencies; neither anesthetic preferentially affects peak twitch tension, maximum rate of contraction, or maximum rate of relaxation.

Anesthesia for cardiac transplantation.

As the number of cardiac transplantation recipients grows, more centers will be performing cardiac transplantations and more anesthesiologists will be confronted with such patients. This chapter is intended to impart to the reader the basic knowledge necessary to manage both the donor and recipient intraoperatively. It is not intended to provide a complete description of the entire field including such areas as the surgical procedure or the immunologic theories involved. Rather, it is hoped that with the information provided, the anesthesiologist may optimally care for this patient group and perhaps become stimulated to investigate this area of medical science in more detailed sources.

A noninvasive method of estimating mean pulmonary artery pressure in the pneumatic total artificial heart.

Accurate hemodynamic monitoring is essential for the clinical management of the recipient of a total artificial heart (TAH). The high incidence of pulmonary congestive disorders in this population complicates this already formidable task. Lack of diagnostic pulmonary artery pressure (PAP) information is recognized as a fundamental source of these problems. Because conventional methods of obtaining hemodynamic information are difficult to implement in TAH recipients, improvement of TAH case management depends on the development of innovative monitoring strategies. Noninvasive monitoring techniques have been developed for three (right atrial pressure, left atrial pressure, and aortic pressure) of the four auxiliary circulatory pressures used to quantify hemodynamic performance. Development of the fourth, for PAP, was the subject of this work. We developed a noninvasive, in vitro method of estimating mean PAP in the Jarvik-7 TAH (Symbion, Inc, Salt Lake City, UT) recipient. This information was obtained by analyzing the relationship between the pneumatic right drive pressure (RDP) and PAP waveforms produced by a Jarvik-7 (70 ml) connected to a Donovan mock circulation and driven by a Utahdrive System IIIe Controller (Symbion, Inc, Salt Lake City, UT). Total artificial heart driver parameters (i.e., heart rate, percent systole, and vacuum) were manipulated to produce a range of ventricular filling volumes (FV), from 40 to 60 ml, for three distinct states of the pulmonary vasculature: hypotensive, normal, and hypertensive. A unique multiple-linear regression equation was derived for each FV from the RDP-PAP relationship exhibited under these conditions. Comparison of computed estimates of PAP with actual measurements showed overall average correlations of greater than 0.92, with a standard error of the estimate of less than 1.9 mm Hg. The mean difference between actual and computed PAP measurements was -0.03 +/- 2.0 Hg. Estimations were accurate within 8.5% of true PAP values. Additional experimentation revealed that while the RDP-PAP relationships are dependent on FV, they are independent of the manner in which FV was obtained. Estimates proved useful over the clinical operating range of the pneumatic heart driver, as well as over the normal physiologic range of PAP in the human. This method is readily applicable to a computer-based monitoring implementation, although its effectiveness needs to be demonstrated in vivo.

Prospective comparison of use of the laryngeal mask and endotracheal tube for ambulatory surgery.

We examined the response to the laryngeal mask (LM) compared to the endotracheal tube (ETT) in patients undergoing ambulatory anesthesia. The differences in management by the anesthesiologists for these two airways were also examined. Peripheral orthopedic procedures were studied in 44 outpatients randomized to receive a LM or ETT, and either spontaneous or controlled ventilation. Anesthesia was induced with propofol and succinylcholine intravenously (i.v.) and maintained with N2O and isoflurane. Anesthesiologists were allowed to determine ventilatory variables and anesthetic concentration. Hemodynamic and ventilatory measurements were made during the anesthesia. Barium sulfate was poured into the oropharynx after the airway was secure. Fiberoptic examination through the LM was performed at the beginning and at the end of the administration of each anesthetic. Radiographs were taken at the end of the anesthetic administration before LM or ETT removal to look for barium in the trachea. After airway removal, presence of blood on the airway, sore throat, coughing, nausea, vomiting, shivering, and amount of morphine demanded during recovery were noted. No barium in the trachea or bronchial tree was seen in any of the radiographs. The ETT was associated with greater hemodynamic response not only to airway placement (P < 0.05), but also to surgical incision (P < 0.05) and airway removal (P < 0.05). Spontaneous or controlled ventilation favored neither airway, although the ETT was associated with increased work of inspiration with controlled ventilation (P < 0.05). Anesthesiologists tended to elect smaller tidal volumes, faster ventilation rates, and lower anesthetic concentrations for patients with the LM (P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Postoperative hypothermia in adults: relationship of age, anesthesia, and shivering to rewarming.

Frequency, magnitude, and duration of hypothermia (core body temperature less than 36.0 C) in the recovery room (RR) were determined in 198 adults. In addition, the influence of age, anesthetic technique, and shivering on the rewarming process was assessed. Tympanic membrane temperatures were recorded on admission to the RR and every 15 minutes thereafter until discharge from the RR. Sixty percent of the subjects had temperatures less than 36.0 C on admission to the RR. Elderly subjects (greater than or equal to 60 yr) had lower RR admission and discharge temperatures and experienced longer duration of hypothermia than did younger patients. General anesthesia was associated with a significantly more rapid rate of increase in postoperative temperature and a shorter duration of hypothermia than was regional anesthesia. The incidence of shivering and the incidence of hypothermia were significantly related 30 and 45 minutes after admission to the RR. Duration of hypothermia varied with different operative procedures.

Succinylcholine pretreatment with magnesium sulfate.

The effect of pretreatment with 60 mg/kg magnesium sulfate on the neuromuscular blockade and consequent potassium release produced by 1.5 mg/kg succinylcholine in ten normal patients was compared with ten saline pretreated control patients. Magnesium had no significant effect on the characteristics of the paralysis. In control patients, serum potassium increased by an average of 0.57 +/- 0.20 (SEM) mmol/L. No patient in the magnesium group had an increase in serum potassium (mean change -0.05 +/- 0.02 mmol/L). The difference between the groups was statistically significant (P less than 0.01).

Effects of halothane and fentanyl anesthesia on plasma beta-endorphin immunoreactivity during cardiac surgery.

We studied the effects of halothane anesthesia (n = 6) and fentanyl anesthesia (n = 9; 50-100 micrograms/kg) on plasma beta-endorphin immunoreactivity as a measure of stress response during coronary artery bypass grafting, including cardiopulmonary bypass. Plasma levels of beta-endorphin immunoreactivity measured prior to induction, after induction, after intubation, after skin incision, during cardiopulmonary bypass, and on leaving the operating room were significantly higher in patients given halothane during cardiopulmonary bypass and on leaving the operating room than they were in patients given fentanyl.

Precision and accuracy of intraoperative temperature monitoring.

Using tympanic membrane (TM) temperature as a standard for core temperature, we quantitated the accuracy and precision of seven other temperature monitoring sites during anesthesia, namely, the nasopharynx, esophagus, rectum, bladder, axilla, forehead, and great toe. Accuracy was quantitated as the difference between TM temperature and the temperature at each of the other sites; precision was quantitated as the correlation between TM temperature and the temperature at each of the other sites. Results indicate that the accuracy of measurements made using the great toe, forehead, and axilla is less than the accuracy of measurements made using the nasopharynx, esophagus, bladder, and rectum. Precision of measurements made using the nasopharynx, esophagus, and bladder is greater than the precision at the axilla, forehead, and rectum, and much higher than the precision at the great toe. Measurements of body temperature using the nasopharynx, esophagus, and bladder are recommended for intraoperative use as providing the best combination of accuracy and precision.

General anesthesia for morbidly obese patients--an examination of postoperative outcomes.

Specific postoperative outcomes were assessed in 67 morbidly obese subjects who received general anesthesia for gastric stapling. Each patient was randomly assigned to receive N2O:O2 combined with fentanyl (n = 20), enflurane (n = 24), or halothane (n = 23). Time from last skin stitch until the patient opened eyes on command was significantly less for the fentanyl group (3.0 +/- 0.7 min) than for the enflurane group (13.2 +/- 1.9 min) or the halothane group (17.4 +/- 2.9 min) with P less than 0.05. However, no significant differences in time from last skin stitch to extubation were noted among the fentanyl (16.2 +/- 7.4 min), enflurane (15.2 +/- 1.6 min), and halothane (21.6 +/- 5.8 min) groups (P greater than 0.05). Recovery room (RR) admission temperatures were similar for the three groups: fentanyl, 36.1 +/- 0.1 degrees C; enflurane, 35.7 +/- 0.2 degrees C; and halothane, 36.0 +/- 0.1 degrees C (P greater than 0.05). Total RR time was not significantly different: fentanyl, 108 +/- 6 min, enflurane, 118 +/- 4 min; and halothane, 112 +/- 10 min (P greater than 0.05). In addition, no difference in RR and 24-hour postoperative narcotic (meperidine) requirements was demonstrated among the anesthetic groups. These data suggest that increased lipid solubility of volatile anesthetics (halothane or enflurane) produces neither delayed awakening nor prolonged recovery time in morbidly obese subjects. Considering the early (24 hour) postoperative outcomes studied, there is little to commend one general anesthetic technique over another in the obese subset of the population.