Evaluation of propofol anesthesia in morbidly obese children and adolescents.

BACKGROUND: Poor characterization of propofol pharmacokinetics and pharmacodynamics in the morbidly obese (MO) pediatric population poses dosing challenges. This study was conducted to evaluate propofol total intravenous anesthesia (TIVA) in this population. METHODS: After IRB approval, a prospective study was conducted in 20 MO children and adolescents undergoing laparoscopic surgery under clinically titrated propofol TIVA. Propofol doses/infusion rates, hemodynamic variables, times to induction and emergence, and postoperative occurrence of respiratory adverse events (RAE) were recorded, along with intraoperative blinded Bispectral Index/BIS and postoperative Ramsay sedation scores (RSS). Study subjects completed awareness questionnaires on postoperative days 1 and 3. Propofol concentrations were obtained at predetermined intra- and post-operative time points. RESULTS: Study subjects ranged 9 - 18 years (age) and 97 - 99.9% (BMI for age percentiles). Average percentage variability of hemodynamic parameters from baseline was ≈ 20%. Patients had consistently below target BIS values (BIS < 40 for >90% of maintenance phase), delayed emergence (25.8 ± 22 minutes), increased somnolence (RSS ≥ 4) in the first 30 minutes of recovery from anesthesia and 30% incidence of postoperative RAE, the odds for which increased by 14% per unit increase in BMI (p ≤ 0.05). Mean propofol concentration was 6.2 mg/L during maintenance and 1.8 mg/L during emergence from anesthesia. CONCLUSIONS: Our findings indicate clinical overestimation of propofol requirements and highlight the challenges of clinically titrated propofol TIVA in MO adolescents. In this setting, it may be advantageous to titrate propofol to targeted BIS levels until more accurate weight-appropriate dosing regimens are developed, to minimize relative overdosing and its consequences.

Staged palliation of hypoplastic left heart syndrome: trends in mortality, cost, and length of stay using a national database from 2000 through 2009.

Staged surgical palliation has revolutionized the care of patients with hypoplastic left heart syndrome (HLHS), although the outcomes of survival and cost at a national level remain unclear. This study sought to evaluate (1) trends in HLHS surgical outcomes including in-hospital mortality, length of stay (LOS), and cost, and (2) patient and hospital risk factors associated with these outcomes. Hospitalizations for patients with HLHS, including stage I, II, and III palliations, were analyzed using the Kids' Inpatient Database from 2000 through 2009. Trends in mortality, LOS, and cost were analyzed and chi-squared tests were used to test association between categorical variables. Patient and hospital characteristics associated with death were analyzed using logistic regression and associations with LOS were analyzed using ordinary least squared regression. There were 16,923 hospital admissions in patients with HLHS of which 5,672 (34%) included surgical intervention. Total (3,201-5,102) and surgery-specific admissions (1,165-1,618) increased from 2000 to 2009. Mortality decreased 14% per year in stage III palliations (odds ratio [OR] 0.86; 95% confidence interval [CI]: 0.79-0.94) and 6% per year for stage I palliations (OR 0.94; 95% CI 0.90-0.99) but not for stage II palliations (OR 1.01; 95% CI; 0.89-1.14). Length of stay increased for stage I and II palliations; however, per-patient hospital cost decreased in 2009. In conclusion, recent decrease in per patient cost for staged surgical palliation for HLHS has correlated temporally with improved mortality.

A comparison of inhalational inductions for children in the operating room vs the induction room.

BACKGROUND: There has been debate about the use of an induction room (IR) compared with an operating room (OR) for inhalational induction in children. The quality of the anesthesia induction between these two physical environments has not been studied previously. We sought to compare child distress, OR utilization and efficiency, and parental satisfaction and safety, between an IR and an OR. METHODS: In a prospective observational study, we studied 501 developmentally appropriate children ages 1-14 years, American Society of Anesthesiologists (ASA) physical status I-III, presenting for the inhalational induction of anesthesia, undergoing outpatient or outpatient-admit ENT surgery. Inductions were performed in an IR (IR group) or OR (OR group) with parent(s) present. Child behavioral compliance was assessed using the Induction Compliance Checklist (ICC), a validated observational scale from 0 to 10 consisting of 10 behaviors; an ICC score ≥4 was considered poor behavioral compliance. Times for transport, anesthesia start, ready for surgery, surgery finish, out of OR, and total case process times were recorded. OR utilization and OR efficiency was derived using these times. Data on number and experience of clinical providers were also collected. Parent satisfaction with the induction was measured using a satisfaction survey. Safety was measured by recording respiratory complications during induction. The chi-squared test was conducted to determine whether induction location was associated with level of behavioral compliance. A multivariable proportional odds model was used to control for risk factors. OR utilization and efficiency were analyzed using the Wilcoxon-Mann-Whitney test. RESULTS: There were no significant differences in ICC scores between the groups (P-value = 0.12). Anesthesia, nonoperative, and transport time were statistically less in the OR group when compared with the IR group, although total case process times were similar in both groups. While OR efficiency was significantly higher for the OR group (P-value = 0.0096), OR utilization did not differ between groups (P-value = 0.288). The OR group had a significantly higher number of anesthesia providers and a more experienced surgical team. Parents in the two groups were equally satisfied with their experience during induction, and none of the subjects had respiratory complications during the anesthesia induction. CONCLUSIONS: We found no differences in child distress, parent satisfaction, and respiratory complications between inductions conducted in the IR vs the OR. Differences in utilization, efficiency, and turnover were minimal and not operationally significant. Capital equipment, space, and staffing strategies should be key drivers in considerations for the use of IRs, and in the design of ORs with IRs.

Preclincial testing of sorafenib and RAD001 in the Nf(flox/flox) ;DhhCre mouse model of plexiform neurofibroma using magnetic resonance imaging.

BACKGROUND: Neurofibromatosis type 1 (NF1) is an inherited disease predisposing affected patients to variable numbers of benign neurofibromas. To date there are no effective chemotherapeutic drugs available for this slow growing tumor. Molecularly targeted agents that aim to slow neurofibroma growth are being tested in clinical trials. So preclinical models for testing potential therapies are urgently needed to prioritize drugs for clinical trials of neurofibromas. PROCEDURE: We used magnetic resonance imaging (MRI) to monitor neurofibroma development in the Nf1(flox/flox) ;DhhCre mouse model of GEM grade I neurofibroma. Based on studies implicating mTOR and Raf signaling in NF1 mutant cells, we tested the therapeutic effect of RAD001 and Sorafenib in this model. Mice were scanned to establish growth rate followed by 8 weeks of drug treatment, then re-imaged after the last dose of drug treatment. Tumor volumes were determined by volumetric measurement. RESULTS: We found that rate of tumor growth varied among mice, as it does in human patients. RAD001 inhibited its predicted target pS6K, yet there was no significant decrease in the tumor volume in RAD001 treated mice compared to the vehicle control group. Sorafenib inhibited cyclinD1 expression and cell proliferation in tumors, and volumetric measurements identified significant decreases in tumor volume in some mice. CONCLUSION: The data demonstrate that volumetric MRI analysis can be used to monitor the therapeutic effect in the preclinical neurofibroma drug screening, and suggest that Sorafenib might have clinical activity in some neurofibromas.

Brief Rating of Aggression by Children and Adolescents (BRACHA): development of a tool for assessing risk of inpatients' aggressive behavior.

This study evaluated the Brief Rating of Aggression by Children and Adolescents-Preliminary Version (BRACHA 0.8), an actuarial method of assessing the risk of aggressive behavior by hospitalized children and adolescents. Licensed psychiatric social workers used a 16-item questionnaire to assess all patients seen in the emergency department (ED) of a major urban children's hospital. Over a six-month period, 418 patients (age range, 3.5-19.0 years) underwent psychiatric hospitalization after ED evaluation. The hospital nursing staff recorded the inpatients' behavior, with the Overt Aggression Scale (OAS). Inpatients were deemed aggressive if, during the first six days of their hospital stay, they scored one or higher on any OAS subscale. We evaluated questionnaire properties, items, and demographic covariates (e.g., age, sex, and living situation) by using factor analyses, logistic regression models, and receiver operating characteristic (ROC) methods. A total of 292 aggressive acts were committed by 120 (29% of 418) patients. Fourteen of the 16 items predicted (p < .007) inpatient aggression and showed good internal consistency (Cronbach's α = 0.837). Age was inversely related to probability of aggression and was incorporated into the final assessment instrument. Predictive power was comparable with other published risk assessment instruments (ROC areas of .75 for any aggression and .82 for aggression toward others). BRACHA 0.8 shows promise in rapidly assessing risk of inpatient aggression, but further studies are needed to establish the reliability and validity of the instrument.

Rising use of CT in child visits to the emergency department in the United States, 1995-2008.

PURPOSE: To describe nationwide trends and factors associated with the use of computed tomography (CT) in children visiting emergency departments (EDs) in the United States between 1995 and 2008. MATERIALS AND METHODS: This study was exempt from institutional review board oversight. Data from the 1995-2008 National Hospital Ambulatory Medical Care Survey were used to evaluate the number and percentage of visits associated with CT for patients younger than 18 years. A mean of 7375 visits were sampled each year. Data were subcategorized according to multiple patient and hospital characteristics. The Rao-Scott χ(2) test was performed to determine whether CT use was similar across subpopulations. RESULTS: From 1995 to 2008, the number of pediatric ED visits that included CT examination increased from 0.33 to 1.65 million, a fivefold increase, with a compound annual growth rate of 13.2%. The percentage of visits associated with CT increased from 1.2% to 5.9%, a 4.8-fold increase, with a compound annual growth rate of 12.8%. The number of visits associated with CT at pediatric-focused and non-pediatric-focused EDs increased from 14,895 and 316,133, respectively, in 1995 to 212,716 and 1,438,413, respectively, in 2008. By the end of the study period, top chief complaints among those undergoing CT included head injury, abdominal pain, and headache. CONCLUSION: Use of CT in children who visit the ED has increased substantially and occurs primarily at non-pediatric-focused facilities. This underscores the need for special attention to this vulnerable population to ensure that imaging is appropriately ordered, performed, and interpreted.

EMG and MRI are independently related to shoulder external rotation function in neonatal brachial plexus palsy.

BACKGROUND: Few studies exist with regard to the ability of electromyography (EMG) and volumetric magnetic resonance imaging (MRI) of the infraspinatus muscle to complement the physical assessment of active global shoulder external rotation (GER) in the neonatal brachial plexus palsy (NBPP) population. Therefore, the purpose of this study was to evaluate the relationships of EMG and MRI with active GER based on analysis of the infraspinatus muscle. METHODS: Seventy-four NBPP patients (mean age, 5 y 1 m; range, 1 y 1 m to 13 y 3 m) who had undergone physical examination of the shoulder, EMG evaluation of the infraspinatus muscle, and shoulder MRI were included in this study. The outcome variable active GER was dichotomized into <0 degree active GER (poor) and ≥0 degree active GER (good). The interference pattern on EMG of the infraspinatus muscle was graded on a 6-point scale and dichotomized into ≤4 and ≥5. On shoulder MRI, infraspinatus muscle volume was measured. The infraspinatus muscle interference pattern and volume were compared with active GER. RESULTS: Interference pattern on EMG of the infraspinatus muscle was significantly related to the Mallet Score (P=0.0022), with a poor interference pattern associated with an approximately 7 times higher likelihood [odds ratio=7.391; 95% confidence interval (2.054, 26.588)] of poor active GER. Infraspinatus muscle volume decrease on MRI was also significantly related to active GER (P=0.0413), with each percent volume decrease corresponding to an increase of 0.094 in the odds of having a poor Mallet Score for active GER [odds ratio=1.094; 95% confidence interval (1.004, 1.193)]. CONCLUSIONS: The interference pattern of the infraspinatus muscle on EMG and the infraspinatus muscle volume on MRI are strongly related to active GER as assessed by the Mallet Score. Integrating clinical assessment with electrophysiological and imaging findings may improve the accuracy in evaluating shoulder dysfunction in NBPP and provide improved guidance in selecting interventions specific to the patient's pattern of deficits. LEVEL OF EVIDENCE: Diagnostic study, level II.

National trends in CT use in the emergency department: 1995-2007.

PURPOSE: To identify nationwide trends and factors associated with the use of computed tomography (CT) in the emergency department (ED). MATERIALS AND METHODS: This study was exempt from institutional review board approval. Data from the 1995-2007 National Hospital Ambulatory Medical Care Survey were used to evaluate the numbers and percentages of ED visits associated with CT. A mean of 30 044 visits were sampled each year. Data were also subcategorized according to multiple patient and hospital characteristics. The Rao-Scott χ(2) test was performed to determine whether CT use was similar across subpopulations. Data were evaluated according to exponential and logistic growth models. RESULTS: From 1995 to 2007, the number of ED visits that included a CT examination increased from 2.7 million to 16.2 million, constituting a 5.9-fold increase and a compound annual growth rate of 16.0%. The percentage of visits associated with CT increased from 2.8% to 13.9%, constituting a 4.9-fold increase and a compound annual growth rate of 14.2%. The exponential growth model provided the best fit for the trend in CT use. CT use was greater in older patients, white patients, patients admitted to the hospital, and patients at facilities in metropolitan regions. By the end of the study period, the top chief complaints among those who underwent CT were abdominal pain, headache, and chest pain. The percentage of patient visits associated with CT for all evaluated chief complaints increased-most substantially among those who underwent CT for flank, abdominal, or chest pain. CONCLUSION: Use of CT has increased at a higher rate in the ED than in other settings. The overall use of CT had not begun to taper by 2007.

Operating room traffic: is there any role of monitoring it?

BACKGROUND: Operating room (OR) human traffic has been implicated as a cause of surgical site infection. We first observed the normal human traffic pattern in our Pediatric Orthopedic ORs, and then examined the effect of surveillance on that traffic pattern. METHODS: This study consisted of 2 phases: phase I sought to observe the OR traffic pattern (number of door swings, maximum and minimum number of OR personnel, number of OR personnel at 30-minute intervals, or changes in nursing, anesthesia, or surgeon staff) during surgical cases without OR personnel being notified, and for phase II, the same traffic pattern was monitored with their knowledge. RESULTS: Two thousand four hundred forty-two minutes of surgical time were observed in phase I, and 1908 minutes were observed in phase II. There was no difference (P=0.06) in the time between door swings between phase I (1.39 min) and phase II (1.70 min), no difference (P=1.000) in the maximum number of people in the OR between phase I (11.5 people, range: 7-15 people) and phase II (11.5 people, range: 8-20 people), and no difference (P=1.000) in the minimum number of people in the OR between phase I (4.67 people, range: 4-6 people) and phase II (4.71 people, range: 3-6 people). There was a difference in the time between door swings (P=0.03) and maximum number of people in the OR (P=0.005) based on the length of the surgery (less or more than 120 min). There was no difference in the time between door swings (P=0.11), but there was a difference in the maximum number of people in the OR (P=0.002) based on type of surgery (spine vs. others). CONCLUSIONS: There was no role of surveillance of human traffic in the OR. To achieve any change in the OR traffic pattern, monitoring alone may not be sufficient; other novel techniques or incentives may need to be considered.

The relationship between amniotic fluid levels of brain-type natriuretic peptide and recipient cardiomyopathy in twin-twin transfusion syndrome.

OBJECTIVE: We sought to evaluate amniotic fluid brain natriuretic peptide (BNP) levels as a biomarker of recipient twin (RT) cardiomyopathy (RTCM) in twin-twin transfusion syndrome. STUDY DESIGN: Amniotic fluid samples were obtained from 157 twin-twin transfusion syndrome RTs and from 6 singletons (controls) from 2007 through 2009. N-terminal prohormone BNP (NT-proBNP) levels were quantified by enzyme-linked immunosorbent assay. RTCM was classified as mild (IIIA), moderate (IIIB), or severe (IIIC) by fetal echocardiography. The relationship between NT-proBNP and RTCM was evaluated using analysis of variance. The ability of NT-proBNP to predict moderate or greater RTCM was evaluated by receiver operating characteristic analysis. RESULTS: There is a significant positive correlation between NT-proBNP levels and worsening RTCM (r = 0.33; P < .001). NT-proBNP thresholds of 569 fmol/mg and 369 fmol/mg had a sensitivity of 70% and 87%, and specificity of 67% and 42%, respectively, in predicting moderate or greater RTCM. CONCLUSION: This is the first large case series that demonstrates a relationship between NT-proBNP and RTCM. This pathophysiologic insight supports ongoing efforts to develop screening biomarkers.

Oral contrast for abdominal computed tomography in children: the effects on gastric fluid volume.

BACKGROUND: Oral enteric contrast medium (ECM) is frequently administered to achieve visualization of the gastrointestinal tract during abdominal evaluation with computed tomography (CT). Administering oral ECM less than 2 hours before sedation/anesthesia violates the nothing-by-mouth guidelines and in theory may increase the risk of aspiration pneumonia. In this study we measured the residual gastric fluid when using a protocol in which ECM is administered up to 1 hour before anesthesia/sedation. We hypothesized that patients receiving ECM 1 hour before anesthesia/sedation would have residual gastric fluid volume (GFV) >0.4 mL/kg. METHODS: Anesthesia and radiology reports, CT images, and department incident reports were reviewed between January 2005 and June 2009 for all patients who required sedation/anesthesia for abdominal CT. For each patient, the volume of contrast or stomach fluid was calculated using a region of interest outlining the stomach portion containing high-attenuation fluid and low-attenuation of other gastric contents. Information obtained from anesthesia/sedation reports included demographic characteristics, presenting pathology, drugs used for anesthesia/sedation induction and maintenance, airway interventions, method for securing endotracheal tube, and complications related to ECM administration, including oxygen desaturation, vomiting, coughing, bronchospasm, laryngospasm, and aspiration. RESULTS: We identified 365 patients (mean age = 32 months; range = 0.66 to 211.10 months) who received oral/IV contrast material before anesthesia/sedation for abdominal CT and 47 patients (mean age = 52 months; range = 0.63 to 215.84 months) who received only IV contrast material and followed the traditional fast. For those who received oral contrast, the mean contrast volume administered was 18.10 mL/kg (range = 1.5 to 82.76 mL/kg). The median GVF 1 hour after completing the oral contrast was significantly higher than that in patients who received only IV contrast (0.38 mL/kg vs. 0.15 mL/kg, P = 0.0049). GFV exceeded 0.4 mL/kg in 189 patients (178 of 365 [49%] in the oral contrast group vs. 11 of 47 [23%] in the IV contrast group) (χ(2) = 10.7874, P = 0.0010). Among those who received oral contrast, 207 patients had general anesthesia and 158 patients had deep sedation. Two cases of vomiting were reported in the general anesthesia group with no evidence of pulmonary aspiration identified. CONCLUSION: For children receiving an abdominal CT, the residual GFV exceeded 0.4 mL/kg in 49% (178/365) of those who received oral ECM up to 1 hour before anesthesia/sedation in comparison with 23% (11/47) of those who received IV-only contrast.

Supplementing desflurane with intravenous anesthesia reduces fetal cardiac dysfunction during open fetal surgery.

OBJECTIVE: To lower the incidence and severity of fetal cardiovascular depression during maternal fetal surgery under general anesthesia. AIM: We hypothesized that supplemental intravenous anesthesia (SIVA) with propofol and remifentanil would lower the need for high-dose inhalational anesthesia and provide adequate maternal depth of anesthesia and uterine relaxation. SIVA technique would minimize prolonged fetal exposure to deep inhalational anesthetics and significant intraoperative fetal cardiovascular depression. BACKGROUND: Fetal hypoxia and significant fetal hemodynamic changes occur during open fetal surgery because of the challenges such as surgical manipulation, hysterotomy, uterine contractions, and effects of anesthetic drugs. Tocolysis, a vital component of fetal surgery, is usually achieved using volatile anesthetic agents. High concentrations of volatile agents required to provide an appropriate degree of uterine relaxation may cause maternal hypotension and placental hypoperfusion, as well as direct fetal cardiovascular depression. METHODS: We reviewed medical records of 39 patients who presented for ex utero intrapartum treatment and mid-gestation open fetal surgery between April 2004 and March 2009. Out of 39 patients, three were excluded because of the lack of echocardiographic data; 18 patients received high-concentration desflurane anesthesia and 18 patients had SIVA with desflurane for uterine relaxation. We analyzed the following data: demographics, fetal medical condition, anesthetic drugs, concentration and duration of desflurane, maternal arterial blood pressure, intraoperative fetal echocardiogram, presence of fetal bradycardia, and need for intraoperative fetal resuscitation. RESULTS: Adequate uterine relaxation was achieved with about 1.5 MAC of desflurane in the SIVA group compared to about 2.5 MAC in the desflurane only anesthesia group (P = 0.0001). More fetuses in the high-dose desflurane group compared to the SIVA group developed moderate-severe left ventricular systolic dysfunction over time intraoperatively (P = 0.02). 61% of fetuses in the high-dose desflurane group received fetal resuscitative interventions compared to 26% of fetuses in the SIVA group (P = 0.0489). CONCLUSION: SIVA as described provides adequate maternal anesthesia and uterine relaxation, and it allows for decreased use of desflurane during open fetal surgery. Decreased use of desflurane may better preserve fetal cardiac function.

Susceptibility of transcranial electric motor-evoked potentials to varying targeted blood levels of dexmedetomidine during spine surgery.

BACKGROUND: Dexmedetomidine has been increasingly used as an adjunct to opioid-propofol total intravenous anesthesia (TIVA). The authors tested the hypothesis and found that clinically relevant blood levels of dexmedetomidine do not produce significant attenuation of the amplitude of transcranial electric motor-evoked potentials either independently or by interaction with propofol in a dose-dependent manner. METHODS: The authors planned to recruit 72 patients with idiopathic scoliosis who had posterior spine fusion surgery during propofol and remifentanil TIVA with dexmedetomidine as an adjunct. However, the authors terminated the study after enrolling 44 patients because of change in surgical technique. Before administering dexmedetomidine, baseline transcranial electric motor-evoked potentials were acquired during TIVA with remifentanil and propofol. Patients were randomized to varying targeted blood levels of dexmedetomidine (0.4, 0.6, and 0.8 ng/ml) and propofol (2.5, 3.75, and 5 microg/ml) using a factorial design. The primary outcome variable was amplitude of transcranial electric motor-evoked potential. The secondary outcome was amplitude of cortical somatosensory-evoked potentials. RESULTS: Of the 44 recruited patients, 40 completed the study, and their data were analyzed. The administration of dexmedetomidine in increasing doses as an adjunct to propofol-based TIVA caused a clinically and statistically significant attenuation of amplitudes of transcranial electric motor-evoked potentials. CONCLUSION: The authors conclude that under the stimulation conditions used, dexmedetomidine as an anesthetic adjunct to propofol-based TIVA at clinically relevant target plasma concentrations (0.6-0.8 ng/ml) can significantly attenuate the amplitude of transcranial electric motor-evoked potentials.

The effect of antibacterial soap on impetigo incidence, Karachi, Pakistan.

We conducted a study to determine if soap containing 1.2% triclocarban would be effective in reducing the incidence of impetigo. We randomized 162 households in a low-income neighborhood of Karachi, Pakistan, to receive a regular supply of 1.2% triclocarban-containing soap (n = 81) or an identically appearing placebo (n = 81); 79 households in a nearby neighborhood were enrolled as standard practice controls. After adjustment for household clustering and covariates, the incidence of impetigo among children living in households receiving triclocarban-containing soap (1.10 episodes per 100 person-weeks) was 23% lower than in households receiving placebo soap (P = 0.28) and 43% lower than the standard habit and practice controls (P = 0.02). The routine use of triclocarban-containing soap by children living in a community with a high incidence of impetigo was associated with a reduced incidence of impetigo.