Ellise Delphin

Use of succinylcholine during elective pediatric anesthesia should be reevaluated.

The occurrence of a cardiac arrest during anesthesia in a child undergoing elective surgery is a rare but devastating event. Arrests due to equipment failure, human error, or misjudgment are potentially preventable by improved monitoring and training of personnel (1-3). Arrests due to the intrinsic properties of drugs or an idiosyncratic or allergic reaction to drugs used in anesthetic practice may be more difficult to prevent, as long as the drugs continue to be used. We now present another case of a prolonged cardiac arrest after succinylcholine use in an apparently healthy child, who was later shown to have occult neuromuscular disease. We suggest that elective use of succinylcholine in pediatric anesthesia should be reevaluated.

Noncardiac surgery in long-term implantable left ventricular assist-device recipients

ObjectiveThe authors describe their experience with left ventricular assist-device (LVAD) recipients undergoing noncardiac surgery and delineate surgical, anesthetic, and logistic factors important in the successful intraoperative management of these patients. Summary Background DataLeft ventricular assist-devices have become part of the armamentarium in the treatment of end-stage heart failure. As the numbers of patients chronically supported with long-term implantable devices grows, general surgical problems that are commonly seen in other hospitalized patients are becoming manifest. Of particular interest is the intraoperative management of patients undergoing elective noncardiac surgical procedures. MethodsThe anesthesia records and clinical charts were reviewed for eight ventricular assist-device recipients undergoing general surgical procedures between August 1, 1990 and August 31, 1994. ResultsA total of 12 procedures were performed in 6 men and 2 women averaging 52.7 years of age. Mean time elapsed from device implantation to operation was 68 ± 35 days. Conventional inhalational and intravenous anesthetic techniques were well tolerated in these patients undergoing diverse surgical procedures. No perioperative mortality was observed. Five of eight patients went on to successful cardiac transplantation. ConclusionsHemodynamic recovery after LVAD insertion has defined a new group of patients who develop noncardiac surgical problems often seen in other critically ill patients. Recognition of the unique potential problems that the LVAD recipient may encounter in the perioperative period—in particular patient positioning, device limitations, and fluid and inotropic management—will ensure an optimal surged outcome for LVAD recipients undergoing noncardiac surgery.

Incidence of atrial fibrillation after mild or moderate hypothermic cardiopulmonary bypass

Objectives: Atrial fibrillation remains a significant source of morbidity after coronary artery bypass grafting (CABG). Whether cardiopulmonary bypass (CPB) temperature influences the occurrence of postoperative atrial fibrillation in CABG patients has not been specifically examined. In the present study, we reviewed postoperative data from patients who were prospectively randomized to mild or moderate hypothermic CPB for elective CABG to determine the incidence of postoperative atrial fibrillation. Design: Randomized, single center, observational study. Setting: Tertiary university medical center. Patients: Adults undergoing elective CABG surgery. Interventions: Enrolled patients were prospectively randomized to mild (34°C [93.2°F]) or moderate (28°C [82.4°F]) hypothermic CPB. Measurements and Main Results: The incidence of postoperative atrial fibrillation was determined by review of ICU and hospital records. There was a significantly higher incidence of atrial fibrillation in the moderate compared with the mild hypothermic CPB group. Patients who had postoperative atrial fibrillation were significantly older than those without atrial fibrillation. Furthermore, a significant increase in the relative risk of developing postoperative atrial fibrillation was found for both age and CPB temperature. Conclusions: Our results indicate that the temperature of systemic cooling during CPB is an important factor in the development of atrial fibrillation after CABG surgery. In addition, this study confirms that increasing age is a significant determinant of postoperative atrial fibrillation.

Jugular Venous Bulb Oxyhemoglobin Saturation During Cardiac Surgery: Accuracy and Reliability Using a Continuous Monitor

Previous studies have demonstrated the feasibility of continuously monitoring jugular venous oxygen saturation (SjO2) with a fiberoptic catheter during hypothermic cardiopulmonary bypass (CPB).In the present study, with patients maintained at either moderate (28 degrees C) or mild (32-34 degrees C) hypothermia during CPB, SjO2 values obtained from a fiberoptic catheter were compared to intermittent samples analyzed by a co-oximeter. Twenty patients scheduled for elective coronary artery or valvular surgery had a 5.5 Fr Opticath catheter inserted into the left internal jugular bulb after induction of general anesthesia. The catheter was calibrated in vitro and in vivo according to the manufacturers specifications. Catheter and co-oximetry SjO2 values obtained at four time points--1) pre-CPB, 2) target CPB temperature, 3) mid-rewarming, and 4) post-CPB--were compared using linear regression, Bland-Altman analysis, and Shrout-Fleiss interclass correlation coefficient analysis. These statistical methods revealed poor correlation between the catheter and co-oximetry SjO2 values: r = 0.44 by linear regression and 0.32 by interclass correlation coefficient analysis, and was unacceptably discrepant by Bland-Altman analysis. Oxyhemoglobin saturation values obtained continuously from a jugular venous bulb fiberoptic catheter during CPB may not accurately reflect true oxyhemoglobin saturation, and caution is warranted when interpreting SjO2 values obtained from a fiberoptic catheter during CPB. (Anesth Analg 1996;82:964-8)

Implantable cardioverter-defibrillator. Evaluation of clinical neurologic outcome and electroencephalographic changes during implantation.

During placement of implantable cardioverter-defibrillators, ventricular arrhythmias are induced to test the function of the devices. Although cerebral hypoperfusion and ischemic electroencephalographic changes occur in patients while implantable cardioverter-defibrillators are being tested, no investigation has assessed neurologic outcome in these patients. Nine patients having either implantation or change of an implantable cardioverter-defibrillator underwent neurologic examination and neuropsychometric tests before and after the operation. After induction of general anesthesia and insertion of implantable cardioverter-defibrillator leads (when needed), ventricular fibrillation, ventricular flutter, or ventricular tachycardia, was induced by means of programmed electrical stimulation. Implantable cardioverter-defibrillator testing continued until satisfactory lead placement was confirmed. The intraoperative electroencephalographic recording was analyzed for evidence of ischemic change. In all, an electroencephalogram was recorded during 50 periods of circulatory arrest. Mean duration of the arrest periods was 13.6 seconds. By means of conventional visual inspection of the raw electroencephalogram, high-amplitude rhythmic delta or theta, voltage attenuation, or loss of fast frequency activity was observed in 30 of the arrests. By means of an automated technique of electroencephalographic interpretation based on power spectral analysis, electroencephalographic changes were correctly identified in 26 of the arrests. The incidence of these electroencephalographic changes was dependent on the arrest duration. The mean interval from arrest onset to electroencephalographic change was 7.5 seconds (standard deviation +/- 1.8 seconds). In patients with electroencephalographic changes during multiple arrests, no downward trend in this interval was detected in later arrests and no evidence of persistent ischemic change was observed in electroencephalograms recorded after the conclusion of implantable cardioverter-defibrillator testing. Postoperative neurologic and neuropsychometric testing was completed in eight patients, none of whom exhibited a new neurologic deficit, exacerbation of a preexisting neurologic condition, or significant deterioration in neuropsychometric performance. We conclude that the brief arrest of cerebral circulation induced during insertion of an implantable cardioverter-defibrillator is not associated with permanent neurologic injury.

Cerebral dysfunction after cardiac operations in elderly patients

BACKGROUND Cerebral injury remains a significant complication of cardiac operations. We determined the incidence of cerebral dysfunction in a population of elderly patients undergoing open chamber cardiac operations (group 1) as compared with a younger population (group 2) and an age-matched group of elderly patients undergoing major noncardiac operations (group 3). METHODS Sixty-eight patients (55 for open chamber cardiac operations and 13 for noncardiac operations) were prospectively studied. Patients were evaluated preoperatively and postoperatively before hospital discharge using a complete neurologic examination and a battery of standard neuropsychometric tests, and at surgical follow-up with neuropsychometric tests only. RESULTS Postoperative changes detected by neurologic examination consisted of the appearance of new primitive reflexes in all groups. No statistically significant differences in incidence were found. The neuropsychometric performance of group 1 patients was statistically different from that of patients in groups 2 and 3 only in the early follow-up period. CONCLUSIONS Elderly patients having open chamber cardiac operations exhibit significantly more cerebral dysfunction in the early postoperative period than those undergoing major noncardiac operations and younger patients after open chamber procedures. These changes do not persist into the late follow-up period.

Sympathetic response during cardiopulmonary bypass: Mild versus moderate hypothermia

OBJECTIVE To determine the sympathetic response during cardiopulmonary bypass at mild (34 degrees C) and moderate (28 degrees C) hypothermia. DESIGN A randomized study. SETTING Tertiary university hospital. PATIENTS Adults undergoing elective coronary artery bypass graft surgery. INTERVENTIONS None. MEASUREMENTS AND MAIN RESULTS Plasma norepinephrine, epinephrine, and neuropeptide Y concentrations were measured. Moderate, but not mild, hypothermic cardiopulmonary bypass evoked a significant sympathetic response with increases in plasma norepinephrine and neuropeptide Y concentrations. A significantly higher incidence of postoperative atrial fibrillation was also observed in the moderate hypothermic compared with the mild hypothermic group. CONCLUSIONS Our results indicate that the degree of hypothermia significantly influences the sympathetic response during cardiopulmonary bypass. The higher incidence of postoperative atrial fibrillation in the moderate hypothermic group suggests that the enhanced sympathetic response might be one contributing factor in the development of atrial fibrillation.

Prophylactic epsilon-aminocaproic acid (EACA) administration minimizes blood replacement therapy during cardiac surgery.

B leeding after cardiopulmonary bypass is a frequent complication of perioperative patient care. To determine whether prophylactic treatment with e-aminocaproic acid (EACA) minimizes bleeding after cardiopulmonary bypass, a retrospective cohort of patients (n = 350) undergoing coronary artery bypass graft (CABG) or valve replacement surgery were evaluated for intraoperative and postoperative allogeneic blood component therapy. We selected EACA as the drug for prophylaxis in order to provide short-term competitive inhibition of the plasmin-mediated conversion of fibrinogen and fibrin to their respective degradation products. Because existing data show that excessive fibrinolytic activity represents a substantial factor in the hemorrhage tendency that follows cardiopulmonary bypass (l-3), we hypothesized that prebypass EACA administration would be a useful adjunct to existing blood conservation techniques.

Safety of repeat aprotinin administration for LVAD recipients undergoing cardiac transplantation

BACKGROUND Anecdotal reports of allergic and anaphylactic reactions after aprotinin therapy have raised concern that its repeat use may be associated with substantial morbidity. METHODS To address this concern, we reviewed our experience with all patients who underwent implantation of a left ventricular assist device and subsequent cardiac transplantation with perioperative use of aprotinin. RESULTS Twenty-three patients received full-dose aprotinin during left ventricular assist device implantation and subsequent cardiac transplantation. All patients tolerated primary exposure to aprotinin without complication. One episode of anaphylaxis after secondary exposure was treated with rapid institution of cardiopulmonary bypass. Although renal dysfunction was observed shortly after cardiac transplantation in 30.4% of patients, the effect was transient and occurred in the presence of cyclosporine. The one perioperative death after secondary exposure was unrelated to bleeding complications. No clinically evident thromboembolic events were documented. CONCLUSIONS Primary and secondary exposure to aprotinin during operation with cardiopulmonary bypass is associated with limited intraoperative blood use, a low incidence of transient renal dysfunction and anaphylaxis, a rare need of reoperation for bleeding, and no clinical thromboembolic events.

A new device to smooth pediatric inhalation induction.

are less than a quarter of the time to loss of conjugate gaze with either halothane or isoflurane quoted by Kingston; our time to tracheal intubation with isoflurane (without neuromuscular blockade or topical anesthesia, and with spontaneous ventilation throughout the procedure) in 49 children was 252 2 30 sec, which is also considerably less than the times to loss of conjugate gaze with either agent quoted by Kingston. In view of the central role played by inhalation anesthesia in such critical situations as failed intubation, the factors that lie behind the difference between our study and Kingstons, and the study by Pandit et al. that Kingston cited (Anesthesiology 1982;59:A445), demand further scrutiny.