Marwan Zidan

Nasopharyngeal airway pressures in bronchiolitis patients treated with high-flow nasal cannula oxygen therapy.

Background Heated, humidified, high-flow nasal cannula oxygen therapy (HHHFNC) has been used to improve ventilation in preterm infants. There are no data on airway pressures generated and efficacy in bronchiolitis. Objective The objective of this study was to determine nasopharyngeal (NP) pressures generated with HHHFNC therapy in bronchiolitis. Methods We conducted a prospective, observational study to measure NP pressures at varying flow rates of HHHFNC therapy in moderate to severe bronchiolitis. Vital signs, bronchiolitis severity scores, and oxygen saturation were also noted. Results Twenty-five patients were enrolled (mean, 78.1 [SD, 30.9] days; weight, 5.3 [SD, 1.1] kg). Nasopharyngeal pressures increased linearly with flow rates up to 6 L/min. Beyond 6 L/min, pressure increase was linear but less accelerated. On average, NP pressure increased by 0.45 cm H2O for each 1-L/min increase in flow rate. There were significant differences between pressures in open- and closed-mouth states for flow rates up to 6 L/min. At 6 L/min, the pressure in open-mouth state was 2.47 cm H2O and that in closed-mouth state was 2.74 cm H2O (P < 0.001). Linear regression analysis revealed that only flow (not weight or gender) had an effect on generated pressure. Bronchiolitis severity scores improved significantly with HHHFNC therapy (pre: 14.5 [SD, 1.4], post: 10.4 [SD, 1.2]; P < 0.001). Conclusions Increasing flow rates of HHHFNC therapy are associated with linear increases in NP pressures in bronchiolitis patients. Larger studies are needed to assess the clinical efficacy of HHHFNC therapy in bronchiolitis.

Cumulative Corticosteroid Exposure and Infection Risk After Complex Pediatric Cardiac Surgery

BACKGROUND Children undergoing cardiac surgery may receive corticosteroids preoperatively to temper cardiopulmonary bypass-related inflammation, postoperatively for hemodynamic instability, and periextubation to reduce airway edema. Recent data have associated preoperative corticosteroids with infection. We aimed to determine if there is a relationship between cumulative corticosteroid exposure and infection. METHODS A retrospective review of children who underwent cardiac surgery at our institution from January 2009 to July 2010 was performed. To limit study heterogeneity, patients who were 5 years or younger with basic Aristotle score of 7 or higher and intensive care unit stay of 7 days or more were included. Infections during the first 30 postoperative days were recorded, defined as clinically relevant positive blood, urine, respiratory, or wound cultures, or culture-negative sepsis treated with 7 or more days of antimicrobial therapy. Multivariate logistic regression analysis was performed to determine independent risk factors for infection. RESULTS Seventy-six patients were reviewed. All patients received intraoperative methylprednisolone, 48% received postoperative hydrocortisone, and 86% received periextubation dexamethasone. Twenty-six patients (36%) had 58 infections. On univariate analysis, patients with infection had greater median comprehensive Aristotle score (14.5 [intraquartile range (IQR): 12.5 to 16] versus 11.5 [IQR: 10 to 13.1], p = 0.001), maximum vasoactive inotrope score (29 [IQR: 24 to 40] versus 24 [IQR: 17 to 31], p = 0.031, days endotracheally intubated (12 [IQR: 7 to 30] versus 5 [IQR: 4 to 6.5], p < 0.001), and days of corticosteroid exposure (7 [IQR: 5 to 12] versus 4 [IQR: 2 to 5), p < 0.001). Also, patients with infections more often underwent delayed sternal closure (p = 0.008). On multivariate analysis, days endotracheally intubated (p = 0.023) and days of corticosteroid exposure (p = 0.015) remained significant. CONCLUSIONS For children undergoing complex cardiac surgery, greater cumulative duration of corticosteroid exposure is independently associated with postoperative infection.

Improving the utilization of admission order sets in a computerized physician order entry system by integrating modular disease specific order subsets into a general medicine admission order set

CASE DESCRIPTION We evaluated the effects of integrating order subsets for the most common medical diagnoses into a general medical admission order set of our electronic medical records (EMR) in order to improve order set integration by clinicians. METHODS OF IMPLEMENTATION We identified the most common primary and secondary diagnoses for patients admitted to our medical service and developed order subsets comprising only of the orders necessary for the management of these individual diagnoses. Using the capabilities of our computerized physician order entry (CPOE), we nested these order subsets into the general order set and evaluated the resulting change in order set utilization by our clinicians. EXAMPLE AND OBSERVATIONS The total number of order sets used by clinicians in all departments increased fivefold during the 16-month period following the implementation of the integrated order sets in July 2008. A before and after time series was used to analyze the trend in increased order set usage and showed an effect of the intervention (p=0.023). DISCUSSION Integration of disease specific order subsets into a single general admission order set significantly improved the overall adoption of order sets by clinicians. This provides health care systems with the opportunity to improve patient safety and implement evidence based care in clinical practice.

Seizure control following palliative resective surgery for intractable epilepsy-a pilot study.

BACKGROUND Patients with intractable epilepsy who have bilateral epileptic foci may not qualify for curative epilepsy surgery. In some cases palliative resection may be undertaken with a goal to decrease seizure frequency and improve quality of life. Here we present data on the outcome of palliative epilepsy surgery in children. METHODS We reviewed medical charts of children who underwent palliative resection for intractable epilepsy during the years 1999-2013 at Childrens Hospital of Michigan. The palliative intent of resection was declared preoperatively. Outcome was assessed in terms of seizure reduction. RESULTS There were 18 patients (11 males, median age of surgery was 3.5 years [range 0.5-16 years]). The median duration of follow-up after surgery was 12.5 months (range 6-60 months). Hemispherectomy was the most commonly performed palliative resection (nine patients), followed by lobectomy (six patients), multilobar resection (one patient), and tuberectomy (two patients). Reduction in seizure frequency was observed in 11 patients, with eight patients achieving seizure freedom on antiepileptic drugs and three with >50% reduction in seizure frequency. Transient improvement in seizure frequency occurred in two patients, whereas there was no benefit in five patients. CONCLUSIONS Beneficial effects of epilepsy surgery may be realized in carefully selected situations wherein the most epileptogenic focus is resected to reduce seizure burden and improve quality of life.

Listeria and enterococcal infections in neonates 28 days of age and younger: Is empiric parenteral ampicillin still indicated?

Introduction Empiric parenteral ampicillin has traditionally been used to treat listeria and enterococcal serious bacterial infections (SBI) in neonates 28 days of age or younger. Anecdotal experience suggests that these infections are rare. Existing data suggest an increasing resistance to ampicillin. Guidelines advocating the routine use of empiric ampicillin may need to be revisited. Objective This study aimed to describe the epidemiology and ampicillin sensitivity of listeria and enterococcal infections in neonates 28 days of age and younger who presented to 2 pediatric emergency departments (ED) in Michigan. Methods We conducted a 2-center, retrospective chart review (2006–2010) of neonates 28 days of age or younger who were evaluated for SBI in the ED. We abstracted and compared relevant demographic, historical and physical details, laboratory test results, and antibiotic sensitivity patterns to ampicillin from the eligible patient records. Results We identified SBI in 6% (72/1192) of neonates 28 days of age or younger who were evaluated for SBI, of which 0.08% (1/1192) neonates had enterococcal bacteremia and 0.08% (1/1192) neonates had listeria bacteremia. A total of 1.4% (15/1192) of patients had enterococcal urinary tract infection (UTI). Urinalysis is less helpful as a screening tool for enterococcal UTI when compared with Escherichia coli UTI (P < 0.001). Seventy-three percent (11/15) of urine isolates had an increase of minimal inhibitory concentrations, which indicate gradual development of resistance to ampicillin. Conclusions Listeria is an uncommon cause of neonatal SBI in febrile neonates who presented to the ED. Empiric use of ampicillin may need to be reconsidered if national data confirm very low listeria and enterococcal prevalence and high ampicillin resistance patterns.

Severe Intraventricular Hemorrhage in Extremely Premature Infants: Are high Carbon Dioxide Pressure or Fluctuations the Culprit?

OBJECTIVE This study aims to examine the association between measures of hypercapnia and fluctuation in Pco 2 and severe intraventricular hemorrhage (IVH) and to evaluate the prevalence of hypercapnia, hypocapnia, and fluctuations in Pco 2 in the initial 72 hours of life among premature infants. STUDY DESIGN Retrospective study of premature infants with birth weight < 1,250 g, who were receiving some respiratory support. All blood gases obtained in the first 3 days of life were collected. Univariate and multivariate analyses were performed to assess the association of hypercapnia, and fluctuations in Pco 2 with severe IVH. RESULT Our cohort included 285 patients, of whom 84% were intubated. Only 20% patients had all blood gases in the normocapnia range; 9% had at least 1 gas with hypercapnia; 51% had at least 1 gas with hypocapnia, and 20% patients had both hypercapnia and hypocapnia at different times. Infants with severe IVH (n = 41) had significantly higher peak Pco 2 and greater fluctuations in Pco 2 within a short interval, compared with those without severe IVH (n = 227). After controlling for gestational age, gender, antenatal steroid exposure, presence of hypercapnia, and Apgar score at 5 minutes, fluctuation in Pco 2 remained significantly associated with severe IVH. CONCLUSION Fluctuations in Pco 2 within a short period may be more significantly associated with severe IVH than the mere presence of hypercapnia.

What you need to know about statistics Part I: validity of diagnostic and screening tests

The intent of this manuscript is to provide guidance and support to clinicians and investigators for reporting the results of screening and diagnostic tests. This article is the first of two parts addressing statistics in imaging research. In this part validity measures are discussed. In part II reliability measures will be discussed. In discussing validity, the following concepts will be introduced: (1) functions of diagnostic tests, (2) statistical characteristics of diagnostic tests and application of validity measures, (3) power and sample size for testing the sensitivity and specificity of the diagnostic test, (4) statistical versus clinical significance and (5) characteristics of a useful diagnostic test.

Hyponatremia during arginine vasopressin therapy in children following cardiac surgery.

Objective: To describe the incidence and severity of hyponatremia after initiation of arginine vasopressin therapy in children recovering from cardiothoracic surgery, and to compare these patients with a control group with similar disease complexity and severity who did not receive arginine vasopressin. Design: Retrospective chart review. Setting: PICU at a tertiary care university hospital. Patients: Twenty-nine patients who received arginine vasopressin for at least 6 hours during the first 48 postoperative hours following cardiothoracic surgery were compared with 47 patients who did not receive arginine vasopressin. After surgery, all patients received intravenous fluids consisting of dextrose and 0.22% saline for daily fluid requirements as well as isotonic colloid and blood products as needed for additional resuscitation. Results: Mean initial postoperative serum sodium did not differ between groups, 144.6 ± 3.4 in those patients who received arginine vasopressin and 144.5 ± 3.7 in those who did not, p = 0.969. Mean lowest sodium in the first 72 hours, however, was 134.7 ± 3.8 in those who received arginine vasopressin as compared with 137.1 ± 4.3 in the control group, p = 0.019. Hyponatremia occurred in 14 of the patients (48%) who received arginine vasopressin but only in 8 of the patients (17%) in the control group, p = 0.004. Mean age, weight, sex, Aristotle score, and duration of cardiopulmonary bypass were not statistically different between groups. Mean volumes of hypotonic fluids administered and cumulative diuretic dosing during the first 72 hours post-surgery were also not statistically different between groups. Conclusions: Hyponatremia occurred in nearly half of the infants and children receiving arginine vasopressin therapy in this study. Clinicians should be aware of this association, monitor serum sodium values closely, and consider providing less free water to these patients before hyponatremia occurs.

Frequency of Otitis Media Based on Otoendoscopic Evaluation in Preterm Infants

Objective This study was conducted to determine the frequency of otitis media in preterm neonates using otoendoscopy and tympanometry. Study Design Prospective study. Setting Wayne State University, Hutzel Women’s Hospital Neonatal Intensive Care Unit. Subjects and Methods Eighty-six preterm infants were included (gestational age <36 weeks). Otoendoscopy and tympanometry were performed to detect the presence of otitis media. Kappa statistic and logistic regression were used for statistical analysis. Results Otoendoscopy was performed in 85 patients. The frequency of otoendoscopy-diagnosed otitis media was 72.9% (62/85). Tympanometry could be performed on 69.76% of the ears. There was 73.5% agreement between the findings of tympanometry and those of otoendoscopy. The association between the presence of otitis media and gestational age at birth was statistically significant. The lower the gestational age, the higher the frequency of otoendoscopy-diagnosed otitis media (P = .001). Conclusion Otoendoscopically diagnosed otitis media is frequent in preterm neonates. There was agreement between the results of tympanometry and those of otoendoscopy. The frequency of otitis media increased with lower gestational age.

Peritoneal Drainage Versus Pleural Drainage After Pediatric Cardiac Surgery

Background: We aimed to determine whether infants undergoing cardiac surgery would more efficiently attain negative fluid balance postoperatively with passive peritoneal drainage as compared to traditional pleural drainage. Methods: A prospective, randomized study including children undergoing repair of tetralogy of Fallot (TOF) or atrioventricular septal defect (AVSD) was completed between September 2011 and June 2013. Patients were randomized to intraoperative placement of peritoneal catheter or right pleural tube in addition to the requisite mediastinal tube. The primary outcome measure was fluid balance at 48 hours postoperatively. Variables were compared using t tests or Fisher exact tests as appropriate. Results: A total of 24 patients were enrolled (14 TOF and 10 AVSD), with 12 patients in each study group. Mean fluid balance at 48 hours was not significantly different between study groups, −41 ± 53 mL/kg in patients with periteonal drainage and −9 ± 40 mL/kg in patients with pleural drainage (P = .10). At 72 hours however, postoperative fluid balance was significantly more negative with peritoneal drainage, −52.4 ± 71.6 versus +2.0 ± 50.6 (P = .04). On subset analysis, fluid balance at 48 hours in patients with AVSD was more negative with peritoneal drainage as compared to pleural, −82 ± 51 versus −1 ± 38 mL/kg, respectively (P = .02). Fluid balance at 48 hours in patients with TOF was not significantly different between study groups. Conclusion: Passive peritoneal drainage may more effectively facilitate negative fluid balance when compared to pleural drainage after pediatric cardiac surgery, although this benefit is not likely universal but rather dependent on the patient’s underlying physiology.