Overweight/obesity and gastric fluid characteristics in pediatric day surgery: implications for fasting guidelines and pulmonary aspiration risk.

BACKGROUND: The safety of 2-h preoperative clear liquid fasts has not been established for overweight/obese pediatric day surgical patients. Healthy children and obese adults who fasted 2 h have small residual gastric fluid volumes (GFVs), which are thought to reflect low pulmonary aspiration risk. We sought to measure the prevalence of overweight/obesity in our day surgery population. We hypothesized that neither body mass index (BMI) percentile nor fasting duration would significantly affect GFV or gastric fluid pH. In children who were allowed clear liquids up until 2 h before surgery, we hypothesized that overweight/obese subjects would not have increased GFV over lean/normal subjects and that emesis/pulmonary aspiration events would be rare. METHODS: Demographics, medical history, height, and weight were recorded for 1000 consecutive day surgery patients aged 2-12 yr. In addition, 1000 day surgery patients (age 2-12 yr) undergoing general endotracheal anesthesia were enrolled. After tracheal intubation, a 14-18F orogastric tube was inserted and gastric contents evacuated. Medications, fasting interval, GFV, pH, and emetic episodes were documented. Age- and gender-specific Center for Disease Control and Prevention growth charts (2000) were used to determine ideal body weight (IBW = 50th percentile) and to classify patients as lean/normal (BMI 25th-75th percentile), overweight (BMI > or = 85th to <95th percentile), or obese (BMI > or = 95th percentile). RESULTS: Of all day surgery patients, 14.0% were overweight and 13.3% were obese. Obese children had lower GFV per total body weight (P < 0.001). When corrected for IBW, however, volumes GFV(IBW) were identical across all BMI categories (mean 0.96 mL/kg, sd 0.71; median 0.86 mL/kg, IQR 0.96). Preoperative acetaminophen and midazolam contributed to increased GFV(IBW) (P = 0.025 and P = 0.001). Lower GFV(IBW) was associated with ASA physical status III (P = 0.024), male gender (P = 0.012), gastroesophageal reflux disease (P = 0.049), and proton pump inhibitor administration (P = 0.018). GFV(IBW) did not correlate with fasting duration or age. Decreased gastric fluid acidity was associated with younger age (P = 0.005), increased BMI percentile (P = 0.036), and African American race (P = 0.033). Emesis on induction occurred in eight patients (50% of whom were obese, P = 0.052, and 75% of whom had obstructive sleep apnea, P = 0.061). Emesis was associated with increased ASA physical status (P = 0.006) but not with fasting duration. There were no pulmonary aspiration events. CONCLUSIONS: Twenty-seven percent of pediatric day surgery patients are overweight/obese. These children may be allowed clear liquids 2 h before surgery as GFV(IBW) averages 1 mL/kg regardless of BMI and fasting interval. Rare emetic episodes were not associated with shortened fasting intervals in this population.

Perioperative course in 118 infants and children undergoing coarctation repair via a thoracotomy: a prospective, multicenter experience.

OBJECTIVE: The hospital course for pediatric coarctation repair has not been described. We had 4 aims: (1) to determine the influence of age, anatomy, and type of repair on aortic crossclamp time, (2) to determine the impact of age or aortic crossclamp time on postoperative morbidity, (3) to describe current antihypertensive strategies, and (4) to describe antihypertensive medications at hospital discharge. METHODS: Data were obtained from a prospective randomized multicenter esmolol safety and efficacy trial. The study included patients who were scheduled for a coarctation repair receiving esmolol as their first-line antihypertensive medication in the operating room (n = 118; weight > or = 2.5 kg and age < 6 years). RESULTS: (1) Patient age and type of coarctation did not affect the aortic crossclamp time. (2) Younger age, but not aortic crossclamp time, was associated with a significantly longer time to extubation and longer hospital length of stay. (3) A combination of esmolol and sodium nitroprusside (Nipride, Roche, Basel, Switzerland) provided excellent early blood pressure control. (4) At discharge, 64% of patients were receiving antihypertensive medications. Older patients were more likely to be discharged with antihypertensive medication (91% of patients aged 2-6 years, P < .0002). CONCLUSION: The study describes a multi-institutional approach to the repair of isolated coarctation in infants and children. Patients repaired by end-to-end anastomosis had shorter aortic crossclamp time, younger patients had longer hospital length of stay, a majority of patients had sodium nitroprusside (Nipride) added to esmolol for early blood pressure control, and older patients were more likely to be discharged with antihypertensive medication.

The safety, efficacy, and pharmacokinetics of esmolol for blood pressure control immediately after repair of coarctation of the aorta in infants and children: a multicenter, double-blind, randomized trial.

OBJECTIVES: Blood pressure control is important after repair of coarctation of the aorta. We report the first prospective multi-institutional trial addressing the safety and efficacy of esmolol after repair of coarctation of the aorta in infants and children. METHODS: The primary objective of this phase IIIb, multicenter, double-blind, randomized, dose-ranging trial was the efficacy of esmolol to control hypertension. Candidates included subjects younger than 6 years and weighing 2.5 kg or more who underwent surgical intervention for coarctation of the aorta and required therapy for systemic hypertension. One hundred sixteen subjects received esmolol: 36 received a low dose (125 microg/kg), 43 received a medium dose (250 microg/kg), and 37 received a high dose (500 microg/kg). The primary outcomes were the change in systolic blood pressure and the need for additional antihypertensive rescue medication 5 minutes after the initiation of esmolol. RESULTS: All dose groups showed a significant decrease from baseline in systolic blood pressure (-9.6 +/- 16.3 mm Hg, P < .001). There were no differences in systolic blood pressure response at 5 minutes between dose groups (high, medium, or low) or age groups. The need for rescue medication at 5 minutes was not different between dose groups. All dose groups showed similar incidences of adverse events. There were no serious adverse events. DISCUSSION: Esmolol can be administered safely to patients younger than 6 years after repair of coarctation of the aorta. In the dose range of 125 to 500 microg/kg, esmolol significantly decreased systolic blood pressure.

The effect of topical tetracaine eye drops on emergence behavior and pain relief after strabismus surgery.

INTRODUCTION: Pediatric strabismus surgery may be associated with postoperative nausea, vomiting, and emergence agitation (restlessness, thrashing, crying, moaning, disorientation). We hypothesize that emergence agitation after strabismus surgery is in part related to pain and that topical tetracaine ophthalmic drops can decrease the intensity and incidence of postoperative pain and emergence agitation. METHODS: Eighty-eight subjects aged 1 to 12 years scheduled for strabismus surgery were enrolled in a double-masked randomized control trial. The patients were randomized to one of three groups: Group A received normal saline drops before and after surgery; Group B received normal saline drops before and tetracaine 1% drops after surgery; Group C received tetracaine 1% drops before and after surgery. An observer masked to group assignment assessed each patient in the postanesthesia care unit (PACU) using both a behavior scale and a modified behavioral pain scale. RESULTS: Patients in Group A were found to be in significantly more pain than Groups B or C at 5 minutes after arrival to the PACU (p < 0.013). Using the behavior scale, a significantly greater proportion of patients in Group A were crying or crying and thrashing at 5, 15, and 30 minutes after arrival to the PACU (5 minutes, p < 0.019; 15 minutes, p < 0.041; 30 minutes, p < 0.021). There was no significant difference between groups in total PACU time, PACU vomiting, PACU morphine use, or pain at home. CONCLUSIONS: Postoperative strabismus surgery pain was improved by the use of preoperative, and pre- and postoperative, tetracaine drops. Emergence agitation was not fully evaluated by the behavioral scale, and therefore, the effect of tetracaine drops on emergence agitation was not clarified. This study suggests that tetracaine drops can lead to a less stressful early postoperative experience for the patient.

Variation in standards of research compensation and child assent practices: a comparison of 69 institutional review board-approved informed permission and assent forms for 3 multicenter pediatric clinical trials.

OBJECTIVE: To systematically compare standards for compensation and child participant assent in informed permission, assent, and consent forms (IP-A-CFs) approved by 55 local institutional review boards (IRBs) reviewing 3 standardized multicenter research protocols. METHOD: Sixty-nine principal investigators participating in any of 3 national, multicenter clinical trials submitted standardized research protocols for their trials to their local IRBs for approval. Copies of the subsequently IRB-approved IP-A-CFs were then forwarded to an academic clinical research organization. This collection of IRB-approved forms allowed for a quasiexperimental retrospective evaluation of the variation in informed permission, assent, and consent standards operationalized by the local IRBs. RESULTS: Standards for compensation and child participant assent varied substantially across 69 IRB-approved IP-A-CFs. Among the 48 IP-A-CFs offering compensation, monetary compensation was offered by 33 as reimbursement for travel, parking, or food expenses, whereas monetary or material compensation was offered by 22 for subject inconvenience and by 13 for subject time. Compensation ranged widely within and across studies (study 1, $180-1425; study 2, $0-500; and study 3, $0-100). Regarding child participant assent, among the 57 IP-A-CFs that included a form of assent documentation, 33 included a line for assent on the informed permission or consent form, whereas 35 included a separate form written in simplified language. Of the IP-A-CFs that stipulated the documentation of assent, 31 specified > or =1 age ranges for obtaining assent. Informed permission or consent forms were addressed either to parents or child participants. CONCLUSION: In response to identical clinical trial protocols, local IRBs generate IP-A-CFs that vary considerably regarding compensation and child participant assent.

A comparison of the costs and efficacy of ondansetron and dolasetron in the prophylaxis of postoperative vomiting in pediatric patients undergoing ambulatory surgery.

UNLABELLED: Postoperative vomiting (POV) after ambulatory surgery remains a major problem. We designed this study to determine the smallest dose of dolasetron equivalent to the Food and Drug Administration approved dose of ondansetron 100 micro g/kg IV, for the prophylaxis of POV in children undergoing surgery. In this double-blinded controlled study, 204 healthy ASA I-II children aged 2-12 yr, undergoing superficial ambulatory (day-case) surgery, were randomized to receive either ondansetron 100 micro g/kg IV, or dolasetron 45, 175, 350, or 700 micro g/kg IV during a standardized perioperative regimen. The primary end-point was the incidence of complete response, defined as the absence of POV symptoms. Costs were calculated from the perspective of the hospital using a previously described model. The incidence of early (0-6 h) and 24-h emesis was more frequent in the dolasetron 45 micro g/kg group compared with the dolasetron 350 and 700 micro g/kg groups and with the ondansetron group. Repeated POV occurred more often when dolasetron was used in a dose <350 micro g/kg. There were no significant differences in emesis rates between the dolasetron 175, 350, and 700 micro g/kg groups or between these groups and the ondansetron 100 micro g/kg group. The smallest dose of dolasetron with acceptable equivalent efficacy and patient satisfaction scores to ondansetron 100 micro g/kg was 350 micro g/kg. Institutional costs for managing POV were less with dolasetron 350 micro g/kg than with ondansetron. IMPLICATIONS: This randomized double-blinded dose-ranging study concluded that dolasetron, 350 micro g/kg IV, was the smallest dose that provided acceptable equivalent efficacy and patient satisfaction scores to ondansetron, 100 micro g/kg IV, for the prophylaxis of postoperative vomiting in children undergoing outpatient surgery. However, with this dose, the costs to the institution for managing postoperative vomiting were less.

A liberalized fasting guideline for formula-fed infants does not increase average gastric fluid volume before elective surgery.

UNLABELLED: Recommended preoperative fasting intervals for infant formula vary from 4 to 8 h. We conducted a prospective, randomized, observer-blinded trial of 97 ASA physical status I and II infants scheduled for elective surgery to determine whether average gastric fluid volume (GFV) recovered from infants formula-fasted for 4 h (liberalized fast, Group L) differed from that recovered from infants allowed clear liquids up until 2 h, but fasted 8 h for formula and solids (traditional fast, Group T). In Group L, 31 of 39 subjects followed protocol and ingested formula 4-6 h before surgery. In Group T, 36 of 58 subjects followed protocol, taking clear liquids 2-5 h before the induction of anesthesia. Thirty subjects had prolonged fasts and were included only in a secondary intent-to-treat analysis. Respective mean age (5.7 +/- 2.3 versus 6.4 +/- 2.4 mo; range, 0.7-10.5 mo), weight (7.5 +/- 1.8 versus 7.5 +/- 1.1 kg), and volume of last feed (4.9 +/- 2.2 versus 4.0 +/- 2.3 oz.) did not vary between Groups L and T. GFV (L: 0.19 +/- 0.38 versus T: 0.16 +/- 0.30 mL/kg) and gastric fluid pH (L: 2.5 +/- 0.5 versus T: 2.9 +/- 1.3) did not vary. For all subjects, GFV (mL/kg) increased with age (Spearman correlation coefficient = +0.23, P = 0.03). Infant irritability and hunger and parent satisfaction were similar between groups. We conclude that average GFV after either a 4- to 6-h fast for infant formula or 2-h fast after clear liquids is small and not significantly different between groups. On the basis of these findings, clinicians may consider liberalizing formula feedings to 4 h before surgery in selected infants. IMPLICATIONS: Healthy infants aged < or =10.5 mo may drink formula up to 4 h before surgery without increasing gastric fluid volume compared with infants allowed clear liquids up to 2 h and formula 8 h before surgery.

A fibrinogen receptor from group B Streptococcus interacts with fibrinogen by repetitive units with novel ligand binding sites.

Group B Streptococcus (GBS) is a frequent cause of bacterial sepsis and meningitis in neonates. During the course of infection, GBS colonizes and invades a number of host compartments, thereby interacting with different host proteins. In the present report, we describe the isolation of the fbsA gene, which encodes a fibrinogen receptor from GBS. The deduced FbsA protein is characterized by repetitive units, each 16 amino acids in length. Sequencing of the fbsA gene from five different GBS strains revealed significant variation in the number of repeat-encoding units. The deletion of the fbsA gene in the genome of GBS 6313 completely abolished fibrinogen binding, suggesting that FbsA is the major fibrinogen receptor in this strain. Growth of the fbsA deletion mutant in human blood was significantly impaired, indicating that FbsA protects GBS from opsonophagocytosis. In Western blot experiments with truncated FbsA -proteins, the repeat region of FbsA was identified as mediating fibrinogen binding. Using synthetic peptides, even a single repeat unit of FbsA was demonstrated to bind to fibrinogen. Spot membrane analysis and competitive binding experiments with peptides carrying single amino acid substitutions allowed the prediction of a fibrinogen-binding motif with the consensus sequence G-N/S/T-V-L-A/E/M/Q-R-R-X-K/R/W-A/D/E/N/Q-A/F/I/L/V/Y-X-X-K/R-X-X.

Airway complications of infant botulism: ten-year experience with 60 cases.

OBJECTIVE: The study goal was to understand the incidence, etiology, and management of airway complications in infant botulism. METHODS: We conducted a retrospective review of the period from January 1, 1987, to December 31, 1997. SETTING: Urban tertiary care children's hospital. RESULTS: Of 60 children with infant botulism, 37 (61.7%) required endotracheal intubation for a mean of 21 days. No patient required a tracheostomy. Airway complications (stridor, subglottic stenosis, granuloma formation) occurred in 5 (13.5%) of 37 patients, with 3 requiring surgical bronchoscopy. Of the 37 children, 14 (37.8%), including 4 with airway complications, had endotracheal tube leak pressures recorded. In 3 (50%) of 6 patients with measured leak pressures of greater than 40 cm H2O, airway complications developed. Complications did not develop in patients with leak pressures of less than 20 cm H2O. No correlation between length of intubation and complications could be established. CONCLUSION: Airway complications in infant botulism may be accompanied by high leak pressures and can be managed with endoscopic techniques. The study data suggest that leak pressures should be measured on a regular basis and maintained at less than 20 to 25 cm H2O. A prospective trial to study this issue is warranted. Tracheotomy is not routinely necessary. A high index of suspicion, early diagnosis, and prompt intervention are required for the optimal management of airway complications in infant botulism.

Cisapride does not prevent postoperative vomiting in children.

UNLABELLED: The peripherally acting prokinetic drug cisapride can overcome opioid-induced gastrointestinal paresis and may thereby eliminate a stimulus for postoperative vomiting. We conducted a prospective, randomized, double-blinded, controlled trial of 96 children undergoing inguinal surgery to determine whether cisapride would reduce the incidence of postoperative vomiting after general anesthesia supplemented with morphine. Group C1 patients (n = 38) received cisapride 0.3 mg/kg orally 1 h before surgery and placebo 6 h later, Group C2 (n = 28) received cisapride both before and after surgery, and Group P (n = 30) received placebo. Mean age (5.0 +/- 2.7 yr) and weight (21.0 +/- 8.6 kg), median pain scores and parent satisfaction scores, and incidence of rescue analgesic administration were similar across groups. Contrary to our hypothesis, incidences of postoperative vomiting in the hospital (32% vs 20%, P = 0.33) and at home (53% vs 46%, P = 0.33) did not vary by treatment group (with [C1 and C2] and without [P] cisapride, respectively). There was a trend toward more severe postoperative vomiting (three or more episodes) in children who received cisapride versus those who did not, both in hospital (6% vs 0%, P = 0.3) and at home (22% vs 8%) (P = 0.13). We conclude that cisapride does not prevent postoperative vomiting in this patient population and speculate that factors other than reduced gastrointestinal motility associated with general anesthesia and opioids are more important determinants of postoperative vomiting. IMPLICATIONS: Cisapride does not prevent postoperative vomiting in children and may increase its severity.