The effect of intranasal administration of remifentanil on intubating conditions and airway response after sevoflurane induction of anesthesia in children.

BACKGROUND: Intubation without the use of muscle relaxants in children is frequently done before IV access is secured. In this randomized controlled trial, we compared intubating conditions and airway response to intubation (coughing and/or movement) after sevoflurane induction in children at 2 and 3 min after the administration of intranasal remifentanil (4 mcg/kg) or saline. METHODS: One hundred eighty-eight children, 1-7-yr old, were studied. Nasal remifentanil (4 mcg/kg) or saline was administered 1 min after an 8% sevoflurane N2O induction. The sevoflurane concentration was then reduced to 5% in oxygen, and ventilation assisted/controlled. An anesthesiologist blinded to treatment assignment used a validated score to evaluate the conditions for laryngoscopy and response to intubation. Blood samples for determination of remifentanil blood concentrations were collected from 17 children at baseline, 2, 3, 4, and 10 min after nasal administration of remifentanil. RESULTS: Good or excellent intubating conditions were achieved at 2 min (after the remifentanil bolus) in 68.2% and at 3 min in 91.7% of the children who received intranasal remifentanil versus 37% and 23% in children who received placebo (P<0.01). The mean remifentanil plasma concentrations (+/-sd) at 2, 3, 4, and 10 min were 1.0 (0.60), 1.47 (0.52), 1.70 (0.46), and 1.16 (0.36) ng/mL, respectively. Peak plasma concentration was observed at 3.47 min. There were no complications associated with the use of nasal remifentanil. CONCLUSIONS: Nasal administration of remifentanil produces good-to-excellent intubating conditions in 2-3 min after sevoflurane induction of anesthesia.

Clinical spectrum and histopathologic features of chronic hepatitis C infection in children.

OBJECTIVE: To define the natural history and outcomes of children infected with hepatitis C virus (HCV) at birth or in early childhood. STUDY DESIGN: This retrospective, prospective study identified 60 HCV-infected children through a transfusion look-back program (group 1) and by referrals (group 2). Perinatal/transfusion history, clinical course, and laboratory studies were correlated with findings from 42 liver biopsy specimens. RESULTS: Mean age at infection was 7.1 months, and duration of infection 13.4 years. The sources of infection were blood transfusion (68%), perinatal transmission (13%), and both (7%). Most patients were asymptomatic; three referral patients had advanced liver disease at presentation. Mean alanine aminotransferase level was normal in 25%, 1 to 3 times normal in 62%, and greater than 3 times normal in 13%. Liver biopsy specimens showed minimal to mild inflammation in 71%, absent or minimal fibrosis in 88%, and bridging fibrosis in 12%. Age at infection and serum gamma-glutamyltranspeptidase correlated with fibrosis; serum alanine aminotransferase correlated with inflammation unless complicated by comorbidity. Repeat biopsies within 1 to 4 years in four patients showed no significant progression in three and cirrhosis in one. Two patients died after liver transplantation. CONCLUSIONS: Children with chronic HCV infection are generally asymptomatic. By 13 years after infection, 12% of patients had significant fibrosis. Patients enrolled by referral had more severe liver disease than those identified through the look-back program, demonstrating the importance of selection bias in assessing the long-term outcome of HCV infection.

Immunohistochemical analyses of MUC5AC mucin expression in sinus mucosa of children with sinusitis and controls.

OBJECTIVES: The purpose of this study was to analyze MUC5AC protein expression in sinus mucosal specimens of children with and without chronic sinusitis. METHODS: Morphometric, histologic, and immunohistochemical analyses were carried out on sinus mucosa of 7 children with chronic sinusitis and 6 children without sinusitis. RESULTS: MUC5AC protein was expressed in a subset of goblet cells in the surface epithelium, but not in the submucosal glands in either pediatric population. The number of goblet cells that expressed MUC5AC mucin was not significantly different in patients with and without chronic sinusitis. All specimens had similar numbers of goblet cells in the surface epithelium. CONCLUSIONS: The data demonstrate that neither goblet cell hyperplasia nor increased MUC5AC expression occurs in the sinus mucosa of children with chronic sinusitis. This suggests that in contrast to asthma, in which goblet cell hyperplasia is present in the lower respiratory tract, mucus hypersecretion in pediatric chronic sinusitis may involve other secretory cells, eg, submucosal glandular cells, and mucins secreted by these glandular cells.

Risk of resistant infections with Enterobacteriaceae in hospitalized neonates.

OBJECTIVE: To determine the risk factors associated with progression from colonization to infection with health care-associated antimicrobial-nonsusceptible Enterobacteriaceae (ANE) in critically ill neonates. STUDY DESIGN: During a 3-year period (1998 to 2000), surveillance rectal cultures were performed on neonates admitted to our Level III neonatal intensive care unit after a cluster of four cases of ANE infection were identified in 1998. ANE were defined as members of the Enterobacteriaceae family that exhibited nonsusceptibility to ceftazidime or laboratory evidence of extended spectrum beta-lactamase (ESBL) production. RESULTS: A total of 1,710 patients were admitted to the neonatal intensive care unit during the study period. Of the 1,710 patients 300 (18%) were excluded from the risk factor analysis. Of the 1,410 remaining neonates the incidence of health care-associated ANE colonization was 17% (240 of 1,410 patients), and 14% of the colonized patients (34 of 240 patients) developed ANE infections. Of the 206 ANE-colonized patients who did not develop disease, 60 (29%) harbored ESBL-producing isolates. Of the 34 ANE-infected patients, 14 (41%) yielded growth of ESBL-producing isolates. Multiple logistic regression analysis revealed that colonized neonates with very low birth weights (<1,000 g) and those who had received prolonged exposures to antimicrobial agents were at increased risk of ANE infections. CONCLUSIONS: Colonization with ANE places hospitalized neonates at risk for development of systemic infections. Very low birth weight (<1,000 g) and prolonged exposure to antimicrobial agents were the only two independent risk factors associated with ANE infection.

Recalibration of the pediatric risk of admission score using a multi-institutional sample.

STUDY OBJECTIVE: Case-mix adjustment is a critical component of quality assessment and benchmarking. The Pediatric Risk of Admission (PRISA) score is composed of descriptive, physiologic, and diagnostic variables that provide a probability of hospital admission as an index of severity. The score was developed and validated in a single tertiary pediatric hospital emergency department (ED) after exclusion of children with minor injuries and illnesses. We provide a multi-institutional recalibration and validation of the PRISA score and test its performance in 4 additional EDs, including patients with minor injuries and illnesses. METHODS: Masked, photocopied, randomly selected medical records of ED patients from 2000 were abstracted and were used to test the performance (discrimination and calibration) of the original PRISA score. This sample differed from the original PRISA sample by including 5 hospitals and including patients with minor injuries and minor illnesses. Independent variables included components of acute and chronic history, physiologic variables, and 3 ED therapies. The dependent variable was hospital admission. PRISA was then recalibrated as needed by using an 80% development sample and a 20% validation sample. Area under the curve and the Hosmer-Lemeshow goodness-of-fit test were used to measure, respectively, discrimination and calibration of the PRISA score after recalibration. We then applied the recalibrated PRISA score to secondary outcomes to test construct validity. We reasoned that a valid measure of ED severity should also be associated with the secondary outcomes of mandatory admissions (admissions using > or =1 inpatient resources) and ICU admissions. RESULTS: The recalibrated PRISA score performed well in all deciles of predicted probability of admission. The area under the curve was 0.81 and the calibration was good (Hosmer-Lemeshow 10.658; df=8; P=.222) for the development sample, and the area under the curve was 0.785 with excellent calibration (Hosmer-Lemeshow 8.341; df=9; P=.500) for the validation sample. The overall development sample had 423.9 admissions predicted and 423 observed; the validation sample had 112.1 predicted and 110 observed. CONCLUSION: The PRISA score has been recalibrated and performs well in EDs of tertiary pediatric hospitals. Comparison with this benchmark may allow individual EDs to improve their performance and may provide insight into best practices.

Increases in serum levels of troponin I are associated with cardiac dysfunction and disease severity in pediatric patients with septic shock.

OBJECTIVES: Myocardial cell injury may contribute to cardiac dysfunction in septic shock. Troponin I is a biochemical marker of myocardial cell injury and death. We hypothesized that troponin I is increased in pediatric patients with septic shock and correlates with cardiac dysfunction and disease severity. DESIGN: Prospective, observational study. SETTING: Children's medical center. PATIENTS: Twenty-three patients with septic shock and cardiovascular failure were enrolled. MEASUREMENTS AND MAIN RESULTS: Serum troponin I was measured at admission and serially over 72 hrs. Within 24 hrs of study enrollment, echocardiograms were performed to determine left ventricular ejection fraction, systolic fractional shortening, heart rate corrected mean velocity of circumferential fiber shortening, and end-systolic wall stress. Requirement for inotropic support (stratified as low, moderate, or high), number of organ system failures, and other demographic data (including Pediatric Risk of Mortality III) were collected. Troponin I was increased on admission in 13 of 23 patients (57%) and at 12 hrs in ten of 22 patients (46%). In all cases, troponin I was maximal within 12 hrs of admission. Admission troponin I was inversely correlated to ejection fraction and fractional shortening and directly correlated to wall stress. Patients who had increased admission troponin I had lower heart rate corrected mean velocity of circumferential fiber shortening (preload and heart rate independent measure of left ventricular systolic function) and higher wall stress (measure of afterload) compared with patients with normal troponin I. Admission troponin I correlated with Pediatric Risk of Mortality III and organ system failure but did not correlate with requirement for inotropic support. CONCLUSIONS: Troponin I was increased in >50% of septic children early in their illness. Increased admission troponin I was associated with decreased measures of systolic cardiac function, as measured by echocardiography, and correlated with severity of illness. Early myocardial cell injury may contribute to the development of subsequent organ failure in septic shock, and measuring troponin I on admission may be helpful in assessing severity of sepsis.

Decreasing variability in faculty ratings of student case presentations: a faculty development intervention focusing on reflective practice.

BACKGROUND: Faculty perceptions of medical student knowledge are often based on case presentations, but their assessment of student performance can vary significantly based on content, presentation skill, and interpersonal characteristics. PURPOSE: To determine if a brief faculty development intervention could significantly decrease (>or= 20%) faculty members' variability in rating student case presentations in the ambulatory setting. METHODS: During the 1998-99 academic year, we videotaped 10 third-year medical students during one well-child presentation. Seven general pediatric faculty rated the videotapes using a validated scoring instrument measuring content: History of Present Illness (HPI), Past Medical History, and Physical Exam (PE); and communication skill: Precision of Language, Fluency, and Economy. Baseline ratings were from June to September 1999 and then repeated in October to November 2000 following a workshop where faculty reflected on the rating process and decreasing rating variance. The change in mean faculty ratings of the student's overall performance and for each item and the change in the mean difference in standard deviation before and after the workshop were analyzed. RESULTS: Internal consistency of the scoring instrument using Cronbach's alpha was 0.88. The mean faculty rating for overall presentation performance and the PE did not significantly change after the workshop, whereas for all other items it did. The mean standard deviation of faculty ratings decreased significantly for the overall performance and all other items except HPI. CONCLUSION: Despite using a validated scoring instrument to rate student case presentations significant variability exists among faculty, with rating inflation likely. A brief faculty development intervention using "reflection-on-action" was associated with more congruent ratings in the short term.

Differences in severity-adjusted pediatric hospitalization rates are associated with race/ethnicity.

OBJECTIVE: Racial/ethnic disparities in health care delivery have been well described, but little is known about such disparities for children who seek emergency care. The objective of this study was to test the hypothesis that severity-adjusted emergency department pediatric admission rates are associated with race/ethnicity. METHODS: Secondary analyses were conducted of an established database of 16 emergency departments that participated in a national study to validate the Pediatric Risk of Admission II score, which is used to measure severity of illness. Patients were randomly selected by the coordinating center from daily emergency department visit logs. Crude and severity-adjusted admission rates were compared among the 3 most common races/ethnicities: white, black, and Hispanic. Adjusted admission rates were calculated by using the standardized admission ratio, which was calculated by dividing the observed admissions by the predicted admissions, when predicted was calculated from the Pediatric Risk of Admission II score. RESULTS: After exclusion of 3 sites that recorded race/ethnicity in <10% of patients, there were 13 sites with 8952 patients in the 3 major race/ethnicity groups. Black and Hispanic patients were similar to each other and different from white patients; therefore, these 2 groups were combined for analyses. Both crude (8.2% vs 5.3%) and severity-adjusted (standardized admission ratio: 1.71 vs 1.1) admission rates were higher in white than in nonwhite patients. Standardized admission ratios were close to 1.0 in both race/ethnicity groups in the higher quintiles of illness severity. In contrast, white patients were admitted at 1.5 to 2 times the expected rate in the lowest 2 quintiles of severity. CONCLUSIONS: There are differences in both crude and adjusted admission rates between white and black/Hispanic patients. The results are more consistent with high rates of discretionary admissions for white patients with low illness severity than with underadmitting severely ill black or Hispanic patients.

Association of emergency department care factors with admission and discharge decisions for pediatric patients.

OBJECTIVE: We evaluated overutilization or underutilization of inpatient resources to measure the emergency department (ED) decision-making process and its association with the following care factors: annual pediatric volume, presence or absence of a pediatric emergency medicine specialist; and presence or absence of ED residents. STUDY DESIGN: Block random selection, using the three care factors, of 16 hospitals with pediatric intensive care units. The Pediatric Risk of Admission (PRISA II) Score was used to measure illness severity. Decision-making was evaluated for admissions (Admission Index: observed minus predicted admissions) and returns (Return Index: observed minus predicted 72-hour returns). The Combined Index was a weighted average of the Admission and Return Indexes. RESULTS: There were 11,664 patients enrolled. Residents but not volume or pediatric emergency medicine specialists were associated with the decision-making performance indexes in multivariable analysis (no residents versus residents: Admission Index: 2.5 of 1000 patients versus 34.8 of 1000, P = .082; Return Index: -3.0 of 1000 versus 33.6 of 1000, P = .039; Combined Index: 1.9 of 1000 versus 35.5 of 1000, P = .024. CONCLUSIONS: There is significant variability in ED decision-making for children. Residents but not volume or presence of a pediatric emergency medicine specialist are associated with increased differences in admission decisions. The process by which these differences occur was not investigated.

The Pediatric Risk of Hospital Admission score: a second-generation severity-of-illness score for pediatric emergency patients.

OBJECTIVE: To develop and validate a second-generation severity-of-illness score that is applicable to pediatric emergency patients. The Pediatric Risk of Admission (PRISA) score was developed in a single hospital and was recalibrated and validated in 2, previous, small studies from academic pediatric hospitals. This study was performed to develop and validate a score in a larger sample of diverse hospitals. METHODS: Emergency departments (EDs) were block randomly selected as part of a study on ED quality on the basis of 3 care characteristics: annual patient volume (high or low compared with national median), presence or absence of a pediatric emergency medicine subspecialist, and presence or absence of residents. Patients were selected randomly on the basis of daily arrival logs. Medical records were photocopied, and abstracted data included demographic, historical, physiologic, and therapeutic information. The total sample was randomly divided into a 75% development sample and a 25% validation sample. Univariate and multivariate analyses were used to model the risk of mandatory admission, admissions for which preidentified, inpatient medical resources were used. The resulting multiple logistic regression model coefficients were converted to integer scores. Calibration (Hosmer-Lemeshow goodness of fit) and discrimination (area under the ROC curve) were used to measure performance. As a measure of construct validity, proportions of patients in ordered risk intervals were correlated with the outcomes of admission, mandatory admission, and ICU admission. RESULTS: Sixteen EDs enrolled 11664 patients. Mean patient age (+/-SD) was 6.8 +/- 5.8 years, and 53% were male. Nine percent arrived by emergency medical services, and 6.9% were admitted. The most common diagnoses were minor injuries, otitis media, and fever. The multivariate analysis yielded a score with 7 historical variables, 8 physiologic variables, 1 therapy (oxygen) term, and 1 interaction term. Calibration was excellent. In the development sample, 442 mandatory admissions were predicted and 442 were observed (total chi2 = 2.275), and in the validation sample, 136.6 were predicted and 145 were observed (chi2 = 8.575). The area under the receiver operator characteristic curve was 0.82 +/- 0.01 (SE) in the development sample and 0.77 +/- 0.02 in the validation sample. In ordered predicted risk intervals, the proportion of patients with admissions, mandatory admissions, and ICU admissions increased in a linear manner. CONCLUSIONS: The second-generation PRISA II score for pediatric ED patients has been developed and validated in a large sample of diverse hospitals. Performance characteristics indicate that PRISA II will be useful for institutional comparisons, benchmarking, and controlling for severity of illness when enrolling patients in clinical trials.

Stable prevalence but changing risk factors for sudden infant death syndrome in child care settings in 2001.

OBJECTIVE: A total of 20% of sudden infant death syndrome (SIDS) cases in the 1990s occurred in child care settings. This is much higher than the 8% expected from Census Bureau data. Factors that were associated with child care SIDS included older age; white race; older, more educated mothers; and unaccustomed prone position. Since these findings, much emphasis has been placed on promoting a safe sleep environment in child care. The objectives of this study were to determine the proportion of SIDS occurring in child care in 2001 and to assess risk factors for SIDS in child care. METHODS: We conducted a retrospective review of all SIDS deaths that occurred in 2001 in 13 US states. Information regarding demographics, SIDS risk factors, and child care arrangements were collected and analyzed. Deaths that occurred in child care were compared with deaths that occurred during parental care. RESULTS: Of 480 deaths, 79 (16.5%) occurred in child care settings. Of these child care deaths, 36.7% occurred in family child care homes, 17.7% occurred in child care centers, 21.3% occurred in relative care, and 17.7% occurred with a nanny/babysitter at home. Infants in child care were more likely to be older and to die between the hours of 8 am and 4 pm and less likely to be exposed to secondhand smoke. There was no difference in usual, found, or placed sleep position between child care and home deaths. Approximately one half of the infants who died of SIDS in both settings were found prone, and 20% of deaths in both settings were among infants who were unaccustomed to prone sleep. CONCLUSIONS: The proportion of SIDS deaths in child care has declined slightly but still remains high at 16.5%. Infants in child care are no more likely to be placed or found prone and no more likely to be on an unsafe sleep surface. Educational efforts with child care providers have been effective and should be expanded to unregulated child care providers. In addition, there may be other, yet-unidentified factors in child care that place infants in those settings at higher risk for SIDS.

CINRG randomized controlled trial of creatine and glutamine in Duchenne muscular dystrophy.

We tested the efficacy and safety of glutamine (0.6 gm/kg/day) and creatine (5 gm/day) in 50 ambulant boys with Duchenne muscular dystrophy in a 6-month, double-blind, placebo-controlled clinical trial. Drug efficacy was tested by measuring muscle strength manually (34 muscle groups) and quantitatively (10 muscle groups). Timed functional tests, functional parameters, and pulmonary function tests were secondary outcome measures. Although there was no statistically significant effect of either therapy based on manual and quantitative measurements of muscle strength, a disease-modifying effect of creatine in older Duchenne muscular dystrophy and creatine and glutamine in younger Duchenne muscular dystrophy cannot be excluded. Creatine and glutamine were well tolerated.

What do adolescents want? An exploratory study regarding end-of-life decision-making.

PURPOSE: To explore whether differences exist between chronically ill and healthy adolescents with regard to their attitudes about end-of-life (EOL) issues. METHODS: A convenience sample of 25 adolescents without and 25 with a chronic illness, aged 13 to 21 years, were surveyed in hospital clinics, using a 25-item instrument; 60% were female and 76% were African-American. Items were developed based on previous research, interviews with health care providers, and a focus group with patients. Data were analyzed using the Fisher's exact test for 2-tailed p values. RESULTS: Ninety-six percent of chronically ill and 88% of healthy teens want to share decision-making if they are very ill; 76% prefer to discuss their wishes earlier in the course of a life-threatening illness. There was a trend for chronically ill adolescents to prefer to wait until later in the course of their illness (32% at diagnosis, 32% when first ill, 20% first hospitalization, or 16% if dying), when compared with their healthy peers (68% at diagnosis, 20% first ill, 4% first hospitalization, 8% if dying) (p = .074). Chronically ill adolescents were significantly more likely to prefer to wait to have these discussions, if the data were collapsed for time (first hospitalized and/or dying) (Fisher's p = .037). Half of all adolescents believed that they would be allowed to change their minds once they had made a decision. Eighty percent of chronically ill and 68% of healthy teens believed that their doctor would respect their wishes, while many were uncertain. CONCLUSIONS: Even teenagers without chronic illness have thoughts about end-of-life issues and have opinions remarkably similar to those of chronically ill teens. Those who are chronically ill are less likely to wish to discuss EOL issues early in their illness.

Pediatric red blood cell transfusions increase resource use.

OBJECTIVE: To test the hypothesis that red blood cell transfusions are associated with increased resource utilization and mortality in critically ill children. METHODS: Five pediatric intensive care units (PICUs) participated in a retrospective, cohort analysis (1996-1999). Children with a hemoglobin value

Ketamine and midazolam is an inappropriate preinduction combination in uncooperative children undergoing brief ambulatory procedures.

BACKGROUND: We prospectively studied the effects of intramuscular (i.m.) ketamine alone, or combined with midazolam, on mask acceptance and recovery in young children who were uncooperative during induction of anaesthesia. METHODS: The Institutional Review Board (IRB) approval was obtained to study 80 children, 1-3 years, scheduled for bilateral myringotomies and tube insertion (BMT). Mask induction was attempted in all the children. Those who were uncooperative were randomly assigned to one of the four preinduction treatment groups: group I, ketamine 2 mg.kg(-1); group II, ketamine 2 mg.kg(-1) combined with midazolam 0.1 mg.kg(-1); group III, ketamine 2 mg.kg(-1) with midazolam 0.2 mg.kg(-1); or group IV, ketamine 1 mg.kg(-1) with midazolam 0.2 mg.kg(-1). Anaesthesia was continued with nitrous oxide and halothane by facemask. RESULTS: Children in all treatment groups achieved satisfactory sedation in less than 3 min following the administration of the preinduction drug(s). Compared with patients who received halothane induction (comparison group), the use of ketamine alone did not significantly (P > 0.0167, a Bonferroni corrected significance level) delay recovery and discharge times (18.8 +/- 2.5 and 82.5 +/- 30.7 min vs 12.6 +/- 4.6 and 81.0 +/- 33.8 min, P = 0.030 and P = 0.941, respectively). Patients who received ketamine/midazolam combinations, however, had significantly longer recovery and discharge times vs halothane (32.3 +/- 14.0 and 128.0 +/- 36.6 min, P = 0.001, P = 0.007, respectively). These times were so clinically unacceptable, that the study had to be terminated with only 17 patients receiving study drugs. CONCLUSIONS: It is concluded that ketamine/midazolam combination is not appropriate for preinduction of anaesthesia in paediatric ambulatory patients because of unacceptably prolonged recovery and delayed discharge times.

Partial pressure of carbon dioxide in extremely low birth weight infants supported by nasal prongs continuous positive airway pressure.

OBJECTIVE: Traditionally, delivery room management of extremely low birth weight (ELBW) infants consisted of immediate intubation and mechanical ventilation. There have been recent reports of success using nasal prongs continuous positive airway pressure (NCPAP) in this population. Data on the partial pressure of carbon dioxide (PCO(2)) in spontaneously breathing ELBW infants is very limited. The objective of this study was to determine the trend of the average PCO(2) in the spontaneously breathing ELBW infants, while on NCPAP, during the first week of life and to determine whether a brief period of mechanical ventilation affects the PCO(2) levels after extubation. METHODS: This is a retrospective cohort study of infants who had birth weights <1000 g and were admitted to the neonatal intensive care unit at our institution. These ELBW infants were divided into groups on the basis of whether they were never intubated (group 1) or were intubated for <48 hours (group 2). Average daily PCO(2) levels while on NCPAP were compared between the 2 groups. Minimum and maximum PCO(2) levels were also compared with a third group of infants (group 3), who were intubated for >48 hours and treated mainly with mechanical ventilation during the first week of life. RESULTS: Sixty-two ELBW infants were included in this study: 24 infants in group 1, 19 infants in group 2, and 19 infants in group 3. There was no significant difference between the average PCO(2) levels of group 1 and group 2 during the first week of life. The daily PCO(2) level during the first week of life for infants who were breathing spontaneously on NCPAP had a mean value of 39.73 +/- 1.78 mm Hg. There was no difference between the daily average minimum PCO(2) levels among the 3 groups. Group 3, however, had significantly higher maximum PCO(2) levels compared with the first 2 groups during days 2 through 7 of life. CONCLUSIONS: Daily average PCO(2) levels in the spontaneously breathing ELBW infants during the first week of life remains at approximately 40 mm Hg. These levels seem to be unaffected by an initial brief period of mechanical ventilation. Infants who are treated with longer periods of mechanical ventilation have higher daily maximum PCO(2) levels during the first week of life. Additional studies are required to detect neurodevelopmental outcomes of these 3 groups.

Neuroselective sensory electrodiagnostic evaluation of 4% liposomal topical lidocaine.

UNLABELLED: We used a neuroselective transcutaneous electrical stimulus to determine the onset time of cutaneous anesthesia with 4% liposomal lidocaine under occluded and nonoccluded conditions. The pain tolerance threshold (PTT) was used to atraumatically evaluate nociception. Twenty adult volunteers had liposomal lidocaine applied to the volar surface of each forearm for durations ranging from 0 through 30 min (at 5-min intervals) under occluded and nonoccluded conditions. The PTT was determined using three different frequencies (2000 Hz, 250 Hz, 5 Hz) stimulating A beta, A delta, and C fibers, respectively. The time to reach the maximum PTT achieved defined the anesthetic onset time for each frequency. A differential onset of cutaneous anesthesia among the three frequencies was clearly demonstrated, however there was no significant difference in onset time between occluded and nonoccluded conditions. Blockade of C fiber transmission occurred significantly earlier than that of A delta (P = 0.029), which occurred earlier than that of A beta (P = 0.001) as determined using the Wilcoxon's signed rank test. We conclude that a mean onset time of approximately 4 +/- 2 min for blockade of C fiber transmission and 6 +/- 4 min for A delta fiber transmission suggests that painful stimuli such as venipuncture may be attenuated as early as 7 min. IMPLICATIONS: An average onset time of approximately 7 min for topical 4% liposomal lidocaine was determined using neuroselective neurostimulation. This suggests that procedural pain such as venipuncture may be attenuated in this time frame. This technique requires correlation with conventional sensory measurements.

Rapid emergence does not explain agitation following sevoflurane anaesthesia in infants and children: a comparison with propofol.

BACKGROUND: Emergence agitation in children is frequently associated with the use of the new highly insoluble volatile anaesthetics. Rapid emergence has been cited as one of the possible causes. Propofol also permits rapid emergence from general anaesthesia but is not associated with agitation. METHODS: The emergence characteristics of children receiving sevoflurane and propofol anaesthesia were examined. After induction with sevoflurane, 53 children, aged 2-36 months, who were undergoing ambulatory surgery, were randomized to receive maintenance anaesthesia with either sevoflurane or propofol. Introperative analgesia with either 2 micro g x kg-1 of intravenous fentanyl or a caudal block with 0.25% bupivacaine was supplied according to surgical procedure. An observer blinded to anaesthetic technique recorded the time to achieve extubation and recovery and assessed emergence behaviour. Data were analysed using Wilcoxon scores, Kruskal-Wallis test, chi-square and multiple regression analysis. RESULTS: The results showed that the time to extubation and recovery were similar between the two study groups, but that emergence agitation was significantly higher in the sevoflurane group compared with the propofol group. No relationship between analgesic technique and agitation scores was found. CONCLUSIONS: Although both sevoflurane and propofol allow for rapid emergence from general anaesthesia, only sevoflurane is associated with a high incidence of emergence agitation in infants and young children. Rapid emergence does not fully explain this phenomena.

Auscultation of bilateral breath sounds does not rule out endobronchial intubation in children.

We performed orotracheal intubation in 153 consecutive pediatric patients undergoing cardiac catheterization. Auscultation of bilateral breath sounds was confirmed. By fluoroscopy, the tip of the endotracheal tube (ETT) was seen in the right mainstem bronchus in 18 patients (11.8%) and in a low position, defined as within 1 cm above the carina, in 29 patients (19.0%). All of the 18 patients with right mainstem intubation were children <120 mo of age, and 7 were infants <12 mo of age (Fisher's exact test; P = 0.013). The age, weight, and ETT size for children who had endobronchial and low tracheal positions were significantly (P < 0.001) less than for those who had midtracheal positions. The failure to diagnose mainstem intubation by auscultation alone may be related to the use of the Murphy eye ETT, which reduces the reliability of chest auscultation in detecting endobronchial intubation. Suggested measures for preventing endobronchial intubation include maintaining increased awareness of the imperfection or lack of accuracy of the auscultatory method, assessing insertion depth by checking the length scale on the tube, and minimizing the patient's head and neck movement after intubation. When extreme flexion or extension of the neck is expected after ETT insertion, the resultant change in ETT final position must be anticipated and taken into consideration when deciding on the depth of ETT insertion. This approach resulted in a decrease in improper tube positioning from 20% when the study was initiated to 7.1% in the last 98 patients.