Evaluation of a pediatric intensive care residency curriculum.

OBJECTIVE: To teach residents to recognize and treat critically ill or injured infants, children, and adolescents in a 1-month, intensivist-designed, second-year resident pediatric intensive care rotation curriculum while maintaining optimal patient care and resident educational satisfaction. DESIGN: Descriptive evaluation of an intensivist-designed, second-year resident pediatric intensive care rotation curriculum from September 1994 to May 1996. SETTING: Multispecialty 16-bed pediatric intensive care unit (ICU) staffed by five pediatric critical care physicians in a university-affiliated children's hospital supporting a pediatric residency program. PATIENTS: None. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Our second-year resident pediatric ICU rotation curriculum consisted of direct patient care, participation in clinical rounds under the supervision of a pediatric critical care attending physician, and a 1-month formal curriculum. A standardized test evaluated resident pediatric critical care knowledge before and after the pediatric ICU rotation. Number and type of resident procedures were documented. Four-point Likert scale questionnaires were used to evaluate resident educational satisfaction and resident performance. Opportunity cost, the graduate medical education return on educational investment, the critical care attending physician's return on resident investment, and the optimal teaching time for number of rotation residents were calculated. Unit demographics were documented. Data analysis included multivariate analysis, t-test, and chi-squared techniques. Significance was defined as p < .05, rotated factor loading > 0.5, and Eigenvalues > or = 1. Kmeans identified clusters. From September 1994 to May 1996, 71 residents, 34 (48%) from pediatric or medicine-pediatric programs and 37 (52%) from emergency medicine residency programs, participated in our second-year pediatric ICU resident educational process. All residents showed improvement between pretest and posttest knowledge scores (p < .05). Seventy percent of the variance in critical care attending physician evaluations of the residents during their pediatric ICU rotation was based on bedside clinical skills (31%), communication skills (20%), and basic knowledge base (19%). Critical care attending physician evaluations of residents placed residents into three clusters: "hands-on," "well-rounded," or "book-heavy" residents. Prerotation test scores, postrotation test scores, and numbers of procedures performed did not correlate with how critical care attending physicians evaluated overall performances of individual residents. Three factors explained 61% of the variances in resident satisfaction with the pediatric ICU rotation: clinical experience (27%), formal didactics (18%), and text availability (16%). Resident educational satisfaction did not appear to depend on access to procedures. Critical care attending physicians spent a minimum of 12.6 hrs/wk involved in resident education. The opportunity cost for using critical care attending physicians to provide 12.6 resident teaching hours per week was calculated as $111,384/yr. Pediatric ICU patient demographics, morbidity, and mortality did not change during the introduction of the resident educational program in the pediatric ICU. CONCLUSIONS: During a required pediatric ICU resident rotation, balancing the resident's educational and decision-making autonomy needs and the critical care attending physician's desire to provide consistent bedside care of the critically ill child is an ongoing interactive process that requires substantial personnel, time, and financial commitments. It is possible to maintain patient care in the pediatric ICU and provide residents with a satisfying pediatric ICU experience. Trends in financial reimbursement may limit our present time commitment to the resident pediatric ICU curriculum.

A study of desmopressin and blood loss during spinal fusion for neuromuscular scoliosis: a randomized, controlled, double-blinded study.

BACKGROUND: Studies examining the use of desmopressin acetate (DDAVP) have shown variable results in DDAVP's efficacy for reducing blood loss. Studies of adults having cardiac surgery and of children having spinal fusion have suggested that patients with complicated medical histories and complex surgical procedures may benefit from use of DDAVP. Therefore, this study was designed to examine the homeostatic effects of DDAVP in children with severe cerebral palsy undergoing spinal fusion. METHODS: A randomized, double-blinded, and placebo-controlled trial of DDAVP was designed to enroll 40 patients. However, termination of the study was advised by the Institutional Review Board after 21 patients were enrolled. All patients had spastic quadriplegic-type cerebral palsy and were randomly assigned to one of two groups. The DDAVP group received 0.3 microg/kg DDAVP in 100 ml normal saline, and the placebo group received normal saline alone. All patients were anesthetized with nitrous oxide, oxygen, isoflurane, and fentanyl. Factor VIIIC and von Willebrand's factor (vWF) concentrations were measured in blood drawn before DDAVP infusion and 1 h after infusion. Blood pressure was maintained at a systolic pressure of less than 100 mmHg. Use of crystalloids, packed erythrocytes, platelets, and fresh frozen plasma were based on criteria established by protocol. Estimated blood loss was assessed by weighing sponges and measuring suctioned blood from canisters. RESULTS: Estimated blood loss (intraoperative and postoperative) and amount of packed erythrocytes transfused were similar for the DDAVP and placebo groups. Concentrations of both factor VIIIC and vWF were significantly greater after DDAVP infusion when compared with concentrations after placebo infusion. CONCLUSIONS: In the children who had complex spinal fusion, there was no difference in estimated blood loss between those who received DDAVP and those who received a placebo. Administration of DDAVP significantly increased factor VIIIC and vWF levels.

Comparison of cuffed and uncuffed endotracheal tubes in young children during general anesthesia.

BACKGROUND: Uncuffed endotracheal tubes are routinely used in young children. This study tests a formula for selecting appropriately sized cuffed endotracheal tubes and compares the use of cuffed versus uncuffed endotracheal tubes for patients whose lungs are mechanically ventilated during anesthesia. METHODS: Full-term newborns and children (n = 488) through 8 yr of age who required general anesthesia and tracheal intubation were assigned randomly to receive either a cuffed tube sized by a new formula [size(mm internal diameter) = (age/4) + 3], or an uncuffed tube sized by the modified Cole's formula [size(mm internal diameter) = (age/4) + 4]. The number of intubations required to achieve an appropriately sized tube, the need to use more than 21.min-1 fresh gas flow, the concentration of nitrous oxide in the operating room, and the incidence of croup were compared. RESULTS: Cuffed tubes selected by our formula were appropriate for 99% of patients. Uncuffed tubes selected by Cole's formula were appropriate for 77% of patients (P < 0.001). The lungs of patients with cuffed tubes were adequately ventilated with 2 1.min-1 fresh gas flow, whereas 11% of those with uncuffed tubes needed greater fresh gas flow (P < 0.001). Ambient nitrous oxide concentration exceeded 25 parts per million in 37% of cases with uncuffed tubes and in 0% of cases with cuffed tubes (P < 0.001). Three patients in each group were treated for croup symptoms (1.2% cuffed; 1.3% uncuffed). CONCLUSIONS: Our formula for cuffed tube selection is appropriate for young children. Advantages of cuffed endotracheal tubes include avoidance of repeated laryngoscopy, use of low fresh gas flow, and reduction of the concentration of anesthetics detectable in the operating room. We conclude that cuffed endotracheal tubes may be used routinely during controlled ventilation in full-term newborns and children during anesthesia.

Preoperative oral ondansetron for pediatric tonsillectomy.

This prospective, randomized, double-blind, placebo-controlled study evaluated the antiemetic efficacy of preoperative oral ondansetron, 0.075 mg/kg or 0.15 mg/kg, in 136 preadolescent children premedicated with midazolam 0.5 mg/kg per os and dexamethasone 0.1 mg/kg intravenously prior to undergoing tonsillectomy with isoflurane anesthesia. The incidence of vomiting during the 24 h after tonsillectomy was significantly reduced (P < 0.04) by ondansetron 0.15 mg/kg compared with placebo and ondansetron 0.075 mg/kg (15%, 38%, and 36%, respectively). There was a significant reduction (P < 0.03) in the mean number of vomiting episodes per patient during the 24 h immediately after tonsillectomy in the ondansetron 0.15 mg/kg group compared with the placebo and ondansetron 0.075 mg/kg study groups (0.2 +/- 0.6, 0.8 +/- 1.3, and 0.8 +/- 1.3, respectively). The need for antiemetic rescue therapy (ondansetron 0.15 mg/kg intravenously after three episodes of emesis prior to discharge) was significantly greater in children who received placebo compared with the ondansetron 0.15 mg/kg study group (13% vs 0%, P < 0.05). We conclude that ondansetron 0.15 mg/kg, administered orally prior to tonsillectomy, is associated with reduced postoperative vomiting in preadolescent children. In addition, the preoperative oral administration of ondansetron 0.075 mg/kg is no more effective than placebo in preventing posttonsillectomy vomiting in preadolescent children.

Ondansetron reduces the incidence and severity of poststrabismus repair vomiting in children.

This prospective, randomized, placebo-controlled, double-blinded study evaluated the antiemetic efficacy of ondansetron and metoclopramide in 90 ASA physical status I or II children, 2-17 yr of age, undergoing strabismus repair. After anesthetic induction and prior to eye muscle manipulation, subjects received normal saline 0.3 mL/kg (Group 1), metoclopramide 0.25 mg/kg (Group 2), or ondansetron 0.15 mg/kg (Group 3), intravenously. There were no differences between groups with respect to age, weight, gender, fluids received, number of eye muscles repaired, anesthetic technique, or time in the operating room. The incidence of vomiting in Groups 1, 2, and 3 was 50%, 27%, and 10% prior to discharge, and 67%, 53%, and 30% during the 24 h after surgery, respectively. The number of children vomiting prior to discharge and within 24 h of surgery was significantly reduced in Group 3 compared with Group 1 (P < 0.003 and P < 0.015, respectively). The number of vomiting episodes per patient in Groups 1, 2, and 3 was 1.1, 0.5, and 0.1 prior to discharge, and 4.5, 2.6, and 1.2 during the 24 h after surgery (P < 0.0005 and P < 0.004, respectively). Ondansetron 0.15 mg/kg intravenously after the induction of anesthesia reduces the incidence and severity of vomiting after strabismus repair both prior to discharge from the hospital and during the 24 h after surgery.

Serum cefazolin levels during spinal fusion: effect of blood loss and duration of surgery.

Perioperative cefazolin prophylaxis is commonly employed in posterior spinal fusion (PSF) procedures, which are often lengthy and involve significant blood loss. In this study, serum levels of prophylactically administered cefazolin were measured serially during spinal fusion procedures, and the possible relationship of antibiotic concentrations to blood loss and fluid therapy were examined. Serum antibiotic levels, measured at 30-min intervals, declined with a half-life of 90 min, similar to the previously reported experience with normal adult volunteers. There was no relationship between serum half-life and blood loss or fluid replacement. An explanation for these findings is offered, along with recommendations for dosing.

Efficacy of intranasal midazolam in facilitating suturing of lacerations in preschool children in the emergency department.

Sedating children safely and effectively for minor laceration repair is a well-recognized clinical problem. A randomized, double-blind, and controlled study was conducted to evaluate the efficacy of intranasal midazolam for reducing stress during the suturing of lacerations in preschool children. Fifty-nine children with simple lacerations that required suturing were randomly assigned to one of three groups. Group 1 received intranasal midazolam, 0.4 mg/kg, prior to suturing. Group 2 received an equivalent volume of normal saline intranasally prior to suturing as a placebo. Group 3 was the control group and received no intervention prior to suturing. Heart rate, respiratory rate, blood pressure, and pulse oximetry were monitored at 5-minute intervals throughout the procedure. Subjective variables were also measured at 5-minute intervals and included a cry score, a motion score, and a struggle score. Parent satisfaction was measured via a short telephone interview the following day. There were no significant differences in outcome between the placebo group and the control group. Their results were pooled and compared with the results for the midazolam group. The midazolam group showed significant reductions for mean heart rate, maximum heart rate, and maximum systolic blood pressure when compared with the placebo/control group. Scores for two of the three subjective variables, cry and struggle, were significantly reduced for the midazolam group. The papoose board was considered unnecessary in retrospect for more than half of patients in the midazolam group compared with only one fifth of patients in the placebo/control group.(ABSTRACT TRUNCATED AT 250 WORDS)

Use of collateral airways to assess airway reactivity.

We investigated the correlation between collateral airway reactivity and other indexes of lung reactivity in response to aerosol and intravenous (iv) challenges. In four anesthetized mongrel dogs, we measured the peripheral airway resistance (Rp) to gas flow out of a wedged lung segment in different lobes on multiple occasions. We obtained dose-response curves of peripheral airways challenged with iv histamine or aerosols through the bronchoscope. During the same iv bolus challenge, whole lung airway pressure (Paw) responses to histamine were also measured. On separate occasions, changes in lung resistance (RL) were measured after the whole lung was challenged with a histamine aerosol. Reactivity was assessed from the dose-response curves for Rp and RL as the PD50 (dose required to produce a 50% increase); for changes in Paw we calculated the PD15 (dose required to produce a 15% increase over baseline). Results for Rp showed considerably more variability among different lobes in a given animal with the aerosol challenge through the bronchoscope than with the iv challenge. With aerosol challenge there were no significant differences in the mean PD50 for Rp among any of the animals. However, with the iv challenge two of the dogs showed significant differences from the others in reactivity assessed with Rp (P less than 0.01). Moreover, the differences found in the peripheral airways with iv challenge reflected differences found in whole lung reactivity assessed with either iv challenge (Paw vs. Rp, r2 = 0.96) or whole lung aerosol challenge (RL vs. Rp, r2 = 0.84). We conclude that the measurement of the collateral resistance response to iv challenge may provide a sensitive method for assessing airway reactivity.

No effect of hyperketonemia on local cerebral glucose utilization in conscious rats.

Local cerebral glucose utilization was measured by the [14C]2-deoxy-D-glucose method in conscious control and hyperketonemic rats. Hyperketonemia was induced by 3 days of starvation or by infusion of 3-hydroxybutyrate in fed rats. These treatments produced combined blood ketone body concentrations (acetoacetate + 3-hydroxybutyrate) of from 1.2 to 2.4 mM. Neither treatment significantly affected glucose utilization in any of the 15 brain regions studied. These observations indicate that hyperketonemia in resting, conscious rats does not interfere with brain uptake and phosphorylation of glucose.

Cerebral metabolic responses to electroconvulsive shock and their modification by hypercapnia.

Brain glucose metabolism was studied in paralyzed, ventilated rats given electroconvulsive shock (ECS) under normocapnic and hypercapnic conditions. Brains were obtained with a freeze-blowing apparatus. Rates of glucose utilization were determined with [2-14C]glucose and [3H]deoxyglucose as tracers. In normocapnic rats, ECS caused a large increase in the rate of glycolysis to 5--6 mumol/g/min. Brain lactate levels increased three- to fourfold. The stimulation of glucose metabolism was reflected in decreased brain glucose 6-phosphate concentration as early as 2--3 s after ECS. There were significant decreases in brain glucose and glycogen levels at 20 and 30 s after ECS. The decreases in endogenous brain glucose accounted for most of the increases in glucose utilization measured isotopically, implying that influx of glucose from blood into brain did not increase greatly over these time periods. Animals made hypercapnic by respiration with 10% CO2 for 2 min prior to ECS were different in their metabolic responses to ECS in several ways. The increases in glycolytic rate and lactate content of brain were half of those found in normocapnic rats. Brain glycogen and glucose concentrations did not change significantly in the hypercapnic rats during seizure activity. Thus, hypercapnia lessened the stimulation of glycolysis caused by ECS, but increased net influx of glucose from blood to brain. The mechanisms of these effects of hypercapnia are uncertain, but it is postulated that the effect on glycolytic activity is due to the acidosis and that the effect on glucose transport is due to an increase in capillary surface area.

Brain carbohydrate metabolism in developing rats during hypercapnia.

Brain glucose metabolism was studied in developing rats at ages 10 and 20 days postnatal under normal and hypercapnic conditions. Brains were removed and frozen within 1 s with a freeze-blowing apparatus. Glucose utilization was measured with [2-14C]glucose and [3H]deoxyglucose as tracers. Metabolites were determined by standard enzymatic techniques. Data from [3H]deoxyglucose phosphorylation indicated that normal brain glucose utilization increased almost threefold between the 10th and 20th postnatal days. From the relative rates of utilization of the two isotopes in the 20-day-old control group, it appeared that about 25% of 14C label derived from metabolism of [2-14C]glucose was lost from brain (probably as lactate) rather than entering the Krebs cycle. Under hypercapnic conditions (20% CO2-21% O2-59% N2), rates of glucose utilization by brain were decreased by one-half at both ages and there were progressive decreases in the concentrations of many intermediary metabolites. The bases for concluding that these metabolites were used to supplement glucose as a fuel for respiration, rather than being lost by leakage into blood, are discussed. Despite the differences in brain glucose metabolism between 10-day-old and 20-day-old rats, their responses to hypercapnia are remarkably similar: Rates of glucose utilization are reduced to approximately the same proportion of the original rate by 20% CO2, and endogenous metabolites (particularly glutamate and lactate) appear to be oxidized as replacement fuels.