Jay H. Shapiro

Frequency of anesthetic cardiac arrests in infants: Effect of pediatric anesthesiologists

STUDY OBJECTIVE To determine whether the presence of pediatric anesthesiologists decreases the frequency of anesthetic-related cardiac arrests in infants (children who are 1 year of age or younger). DESIGN A comparative retrospective study of anesthetics and cardiac arrests during a 7-year period. SETTING The main operating room (OR) suite of a large university hospital. PATIENTS All patients age 1 year or less undergoing surgical anesthesia from July 1983 through March 1990. INTERVENTIONS Computerized anesthetic and operative patients records were queried for patient age, ASA physical status, body weight, surgical procedure, intraoperative complications, and the identity of the attending anesthesiologist. In each case, it was determined whether a pediatric anesthesiologist was in attendance and whether a cardiac arrest due to anesthesia occurred. Pediatric anesthesiologists were identified as those with pediatric fellowship training or the equivalent. The study population was divided into two groups: (1) the pediatric anesthesiologist group, with 2,310 patients whose anesthetics were supervised by pediatric anesthesiologists; (2) the nonpediatric anesthesiologist group, with 2,033 patients. MEASUREMENTS AND MAIN RESULTS Mean age and weight were comparable in the two groups, and the distribution of physical status did not differ. No anesthesia-related cardiac arrests occurred in the pediatric anesthesiologist group; four anesthetic cardiac arrests occurred in the nonpediatric anesthesiologist group, for a frequency of 19.7 per 10,000 anesthetics. This difference between provider groups is significant (Fishers exact probability test, p = 0.048). CONCLUSIONS The results suggest that the use of pediatric anesthesiologists for all infants 1 year of age or younger might decrease anesthetic morbidity in this age-group.

Bradycardia during anesthesia in infants. An epidemiologic study.

Background:The frequency and morbidity of bradycardia during anesthesia in infants are not well documented. This study sought to determine the frequency of bradycardia during anesthesia in infants (0 to 1 yr) compared to that in older children, describe causes and morbidity, and identify factors that influence its frequency. Methods:Computerized information abstracted from 7,979 anesthetic records of patients ages 0–4 yr undergoing non-cardiac surgery were examined for the presence or absence of intraoperative bradycardia. To study bradycardia in infants, 4,645 anesthetics in patients aged 0–1 yr were considered. Those with bradycardia to heart rates less than 100 beats/min were examined for causes, morbidity, and treatment of the bradycardia. For analysis of influencing factors, the frequency of bradycardia in infants was related to age, sex, race, ASA physical status, surgical site (body cavity), complexity (major or minor) and duration, type of primary anesthetist, type of supervising anesthesiologist, and anesthetic agents. Logistic regression was used to estimate the significance (P < 0.05) and odds ratios for each. Results:The frequency of bradycardia was 1.27% In the 1st yr of life, but only 0.65% in the third and 0.16% in the 4th yr, a significant difference. Causes of bradycardia in infants included disease or surgery in 35%, the dose of inhalation agent in 35%, and hypoxemia in 22%. Morbidity included hypotension in 30%, asystole or ventricular fibrillation in 10%, and death in 8%. Treatment involved epinephrine in 30% and chest compression in 25%. Associated factors included an ASA physical status of 3–5 (vs. 1 or 2) and longer (vw. shorter) surgery. Bradycardia was less than half as likely when the supervising anesthesiologist was a member of the Pediatric Anesthesia Service as with other anesthesiologists (P < 0.001). Conclusions:Bradycardia is more frequent in infants undergoing anesthesia compared to older children and is associated with substantial morbidity. It is more likely in sicker infants undergoing prolonged surgery and less likely when a pediatric anesthesiologist is present.

Raising eyebrows: problems that get anesthesiologists' attention.

There are many clinical situations of concern that may be unique to pediatric anesthesiologists. The author discusses four of the more common presentations: asthma, cystic fibrosis, anterior mediastinal masses, and latex allergy. Many such issues can be resolved before surgery by consultation with members of the operating team. Some issues may require additional input from nonsurgical pediatric specialists. By maintaining good communication between the anesthesiologist and the surgeon, delays and cancellations can be minimized and patient care enhanced.

Methemoglobin levels during prolonged combined nitroglycerin and sodium nitroprusside infusions in infants after cardiac surgery

Nitroglycerin (NTG) and sodium nitroprusside (SNP) are routinely used perioperatively in infants with congenital heart defects. In this study, NTG and SNP were infused in the operating room to increase venous capacitance, reduce systemic and pulmonary afterload, facilitate weaning off cardiopulmonary bypass, stabilize hemodynamics for transport to the intensive care unit (ICU), and reduce the fluid resuscitation needed upon arrival in the ICU. Because of the risk for accumulation of methemoglobin (MetHb) and cyanmethemoglobin (cyan-MetHb) during prolonged continuous infusion of NTG and SNP, it was decided to (1) quantify ICU use, (2) measure % MetHb at 12-hour intervals, and (3) look indirectly for the accumulation of cyan-MetHb by comparing simultaneous pulse oximetry (SpO2) (Nellcor N-100 [Nellcor, Haywood, CO]) and CO-oximetry (SaO2) (Corning 270 [Corning, Medfield, MA]). A total of 69 arterial samples were obtained from 16 infants (median age 4.4 months) following cardiac surgery with bypass. Median doses of NTG, 6.0 mg/kg (range 0.7 to 27.5), and SNP, 3.3 mg/kg (range 0.6 to 33.4), were infused over a median of 64.5 hours (range 12 to 183) (N = 16 patients). The median MetHb was 0.6% (range 0.0 to 1.5) after infusions of NTG, 1.8 micrograms/kg/min (range 0.5 to 4), and SNP, 1.3 micrograms/kg/min (range 0.3 to 8.4) (N = 69 measurements). Regression analysis of oximetry data yielded the equation: SpO2 = 1.04 SaO2 - 3.7%, r = 0.97. The mean difference between SpO2 and SaO2 data pairs was 0.0% (bias) with a SD (precision) of +/- 2.3%.(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesia by the pediatric specialist.

There is increasing evidence that involvement of pediatric anesthesiologists in the perioperative care of infants and children can positively impact outcome. Considerable data have emerged in the past several years that clearly show that infants and small children experience untoward events at a much higher rate than do older children and adults. Herein the author presents some of this literature as well as data suggesting that anesthesiologists with interest and additional training in the care of infants and children can improve anesthesia outcomes. Even in these days of cost containment, it makes sense to provide the best pediatric team to care for the pediatric patient during the perioperative experience.