John Palmisano

Respiratory syncytial virus morbidity and mortality estimates in congenital heart disease patients: a recent experience.

ObjectiveTo determine recent morbidity and mortality rates from respiratory syncytial virus infection in a pediatric congenital heart disease population. DesignRetrospective cohort study design. SettingThe C. S. Mott Childrens Hospital, University of Michigan Medical Center. PatientsA total of 740 pediatric patients hospitalized at the University of Michigan Medical Center for symptomatic respiratory syncytial virus infection, of whom, 79 patients had clinically important congenital heart disease. InterventionsNone. Measurements and Main ResultsWe retrospectively examined the charts of 740 patients hospitalized at our childrens hospital from July 1, 1983 to June 30, 1990 with symptomatic respiratory syncytial virus infection to assess morbidity and mortality outcomes. Seventy-nine patients had congenital heart disease and 40 of these patients had pulmonary hypertension. For the entire cohort and a subset of patients with community-acquired infection, those patients with congenital heart disease had longer durations of hospitalization and greater need for, and days of, both intensive care and mechanical ventilation than patients without congenital heart disease. Mortality risk for respiratory syncytial virus community-acquired infection was not different for congenital heart disease vs. noncongenital heart disease patients (0.0% vs. 0.2%; p = 1.00). When examining only patients with congenital heart disease, those patients with pulmonary hypertension had increased hospital days and greater intensive care and mechanical ventilation durations compared with patients without this diagnosis. The overall mortality rate was low and was equally low for congenital heart disease groups with or without pulmonary hypertension (2.5 vs. 2.6). For community-acquired illness, no mortality was found in either congenital heart disease group. When the cohort of congenital heart disease patients was divided into pre- and postribavirin administration eras, no differences in mean hospital duration, ICU days, and mechanical ventilation days were noted. Of the 79 congenital heart disease patients, only two died during their hospitalization in which respiratory syncytial virus infection occurred. Both patients had nosocomial-acquired respiratory syncytial virus and both were from the postribavirin administration cohort. One of these two patients had received antiviral therapy. Neither death was secondary to respiratory syncytial virus respiratory failure (based on pathologic examination). ConclusionsWe conclude that respiratory syncytial virus mortality risk in pediatric patients with congenital heart disease is less than the risk reported a decade ago. Respiratory syncytial virus infection in congenital heart disease patients with pulmonary hypertension is associated with increased morbidity but not increased mortality rates. The markedly decreased respiratory syncytial virus mortality risk in patients with congenital heart disease currently experienced is likely secondary to improvements in intensive care management and advances in the surgical correction in this population rather than antiviral therapy.

Predictors of Habitual Snoring and Obstructive Sleep Apnea Risk in Patients With Asthma

BACKGROUND A high prevalence of obstructive sleep apnea (OSA) symptoms was reported in patients with asthma. Our goal was to evaluate factors associated with habitual snoring and OSA risk in these patients. METHODS Patients with asthma were surveyed at specialty clinics with the Sleep Apnea scale of the Sleep Disorders Questionnaire (SA-SDQ) and questions about the frequency of asthma symptoms (National Asthma Education and Prevention Program guidelines), followed by medical record review. SA-SDQ scores >or= 36 for men and >or= 32 for women defined high OSA risk. Logistic regression was used to model associations with habitual snoring and high OSA risk. RESULTS Among 244 patients, 37% snored habitually and 40% demonstrated high OSA risk. Independent predictors of habitual snoring included gastroesophageal reflux disease (GERD) [odds ratio (OR), 2.19; 95% confidence interval (CI), 1.19 to 4.02] and use of an inhaled corticosteroid (ICS) [OR, 2.66; 95% CI, 1.05 to 6.72]. High OSA risk was predicted by asthma severity step (OR, 1.59; 95% CI, 1.23 to 2.06), GERD (OR, 2.70; 95% CI, 1.51 to 4.83), and ICS use (OR, 4.05; 95% CI, 1.56 to 10.53). Linear, dose-dependent relationships of ICS with habitual snoring and high OSA risk were seen (p = 0.004 and p = 0.0006, respectively). Women demonstrated a 2.11 times greater odds for high OSA risk (95% CI, 1.10 to 4.09) when controlling for the above covariates. CONCLUSIONS Symptoms of OSA in patients with asthma are predicted by asthma severity, coexistent GERD, and use of an ICS in a dose-dependent fashion. The well-recognized male gender predominance for OSA symptoms is not apparent in these patients. Further exploration of these relationships may help to explain the increased prevalence of OSA in asthma and provide new insights into the reported female predominance of asthma morbidity.

Extracorporeal life support for pediatric respiratory failure : predictors of survival from 220 patients

The purpose of this report was to examine the Extracorporeal Life Support Organization registry database for predictors of outcome for severe pediatric respiratory failure managed with extracorporeal life support. Design:Retrospective cohort study. Setting:Extracorporeal Life Support Organization data registry. Patients:All nonneonatal pediatric patients who were treated in the United States with extracorporeal life support for severe pediatric respiratory failure reported to the Extracorporeal Life Support Organization registry as of August 1991. Patients with congenital heart disease and congenital gastrointestinal malformations were excluded from study. Interventions:Venoarterial or venovenous extracorporeal life support for severe life-threatening pulmonary failure. Measurements and Main Results:As of August 1991, 220 pediatric patients meeting study entry criteria were reported to the Registry having received extracorporeal life support for severe pulmonary failure, since 1982. Forty-six percent (102 of 220 patients) were successfully managed with this technology and survived to hospital discharge. The mean patient age was 36.8 ± 51.6 months. Fifty-one percent of the patients were male. The mean duration of mechanical ventilation before extracorporeal life support was 6.3 ± 5.9 days. Mean blood gas and ventilatory measurements obtained before extracorporeal life support were as follows: Paco2 52 ± 23 torr (6.9 ± 3.0 kPa); Pao2 59 ± 32 torr (7.8 ± 4.3 kPa); estimated alveolar-arterial oxygen gradient 561 ± 63.4 torr (74.8 ± 8.5 kPa); peak airway pressure 49.5 ± 13.1 cm H2O; mean airway pressure 24.3 ± 8.2 cm H2O; positive end-expiratory pressure 11.8 ± 6.3 cm H2O; ventilator rate 58 ± 64.4 breaths/min; and FIO2 0.98 ± 0.07. The mean duration of extracorporeal life support for all patients was 247 ± 164 hrs. For the 102 survivors, the mean time for decannulation from extracorporeal life support to extubation from mechanical ventilation was 6.5 ± 7.6 days. Step-wise multivariate logistic regression modeling found the following variables to be associated with patient survival: a) patient age, b) days of mechanical ventilation before extracorporeal life support, c) peak inspiratory pressure, d) alveolar-arterial oxygen gradient, and e) extracorporeal life support administered since December 31, 1988 (all p < .05). Conclusions:Extracorporeal life support may represent an effective rescue therapy for some selected pediatric patients with severe respiratory failure for whom conventional mechanical ventilation support has failed to improve. Predictors of survival for this life-support therapy exist that may be helpful for individual patient prognostication and future prospective study. (Crit Care Med 1993; 21:1604–1611)

Extracorporeal life support for severe pediatric respiratory failure: An updated experience 1991–1993

Objective: The purpose of this study was to examine our recent experience with children who had acute respiratory failure managed with extracorporeal life support (ECLS) from 1991 to 1993, to determine whether a change in survival rate had occurred in comparison with our previous experience. Design: Historic and prospective cohort study. Setting: A tertiary pediatric referral center. Patients: All nonneonatal pediatric patients treated with ECLS for severe, life-threatening respiratory failure were examined. Overall, 25 patients have been managed with this life-support technique in the past 28 months. Eighty-four percent (21/25) were transferred to our medical center because of failure of conventional mechanical ventilation therapy. Descriptive data of the recent cohort were as follows (mean ± SD): age 60±75 months, weight 23.6±24.8 kg, and male gender 44%. Duration of intubation before ECLS was 5.8±2.7 days. Arterial blood gas values and ventilator settings immediately before ECLS were as follows: fraction of inspired oxygen, 0.98±0.08; mean airway pressure, 21.6±6.2 cm H2O; peak inspiratory pressure, 45.5±9.6 cm H2O; positive endexpiratory pressure, 11.0±4.3 cm H2O; partial pressure of oxygen (arterial), 56±20 mm Hg (7.4±2.7 kilopascals); partial pressure of carbon dioxide (arterial), 46±17 mm Hg (6.1±2.3 kPa); and estimated alveolar-arterial oxygen tension difference, 572±81 mm Hg (76.3±10.8 kPa). Mean duration of ECLS was 373±259 hours. Of 25 recently treated patients, 22 (88%) survived their lifethreatening respiratory illness to be discharged home; this represented a statistically improved survival rate in comparison with the 58% survival rate previously reported by us for similar patients (p Conclusions: Treatment with ECLS is an evolving pulmonary rescue therapy with an 88% survival rate in our recent experience. The survival rate has improved to levels that may not greatly improve in the near future, especially for patients less than 1 year of age. Better patient selection or improved management strategies or both may be responsible for the improved patient outcome.

Extracorporeal life support for pediatric respiratory failure

ObjectivesThe purposes of this report are to a) describe the University of Michigan experience with venoarterial or venovenous extracorporeal life support for severe pediatric pulmonary rescue therapy, and b) examine survivors and nonsurvivors for differences that might be useful for examination in future, prospective studies. DesignCase series report. Phase I study of safety and effectiveness of extracorporeal life support for pediatric respiratory failure. SettingUniversity of Michigan Medical Center. PatientsNon-neonatal pediatric patients treated with extracorporeal life support for severe respiratory failure at the University of Michigan. InterventionsExtracorporeal life support for pulmonary failure. Measurements and Main ResultsFrom November 1982 until May 1991, 25 pediatric patients underwent extracorporeal life support for severe pulmonary failure. Twenty patients were treated in the last 36 months. Sixty percent (15/25 patients) survived their life-threatening respiratory illness, were weaned from mechanical ventilation, and were discharged home. The mean patient age was 4.1 yrs, and mechanical ventilation duration before extracorporeal life support was 5.9 days. Mean blood gas data and mechanical ventilation pressures before extracorporeal life support were: peak inspiratory pressure of 48.6 cm H2O, mean airway pressure of 21.9 cm H2O, positive end-expiratory pressure of 9.7 cm H2O, PaCO2 of 43 torr (5.7 kPa), PaO2 of 69 torr (9.1 kPa), estimated alveolar-arterial oxygen gradient of 563 torr (75 kPa), and FIO2 of 0.98. Variables associated with survival included: age of survivors vs. nonsurvivors, 2.1 vs. 7.1 yrs (p < .02); peak inspiratory pressure of survivors vs. nonsurvivors, 43.1 vs. 57.9 cm H2O (p < .03); mean airway pressure of survivors vs. nonsurvivors, 18.4 vs. 27.2 cm H2O (p < .03); and positive end-expiratory pressure of survivors vs. nonsurvivors, 8.1 vs. 12.1 cm H2O (p < .01). There were no differences detectable in the blood gas values (PaO2, PaCO2, P[A-a]O2) in survivors and nonsurvivors before extracorporeal life support. The number of days mechanical ventilation was used before extracorporeal life support in survivors and in nonsurvivors was similar. ConclusionExtracorporeal life support is an effective rescue therapy for pediatric patients with severe respiratory failure (University of Michigan survival rate of 60%). (Crit Care Med 1992; 20:1112–1118)

Predictors of outcome of severe respiratory syncytial virus-associated respiratory failure treated with extracorporeal membrane oxygenation

OBJECTIVE To examine the Extracorporeal Life Support Organization registry data base for all infants and children with respiratory syncytial virus-associated respiratory failure managed with extracorporeal life support, to delineate predictors of outcome. DESIGN Retrospective cohort study. SETTING Extracorporeal Life Support Organization data registry. PATIENTS All pediatric patients treated in the United States with extracorporeal life support for severe pediatric respiratory syncytial virus-associated respiratory failure reported to the registry, from 1982 through June 1992. INTERVENTIONS Venoarterial or venovenous extracorporeal life support. MEASUREMENTS AND MAIN RESULTS As of June 1992, fifty-three pediatric patients meeting study entry criteria were reported to the Pediatric Respiratory Failure Registry (n = 412) as having received extracorporeal membrane oxygenation (ECMO) for severe respiratory syncytial virus infection with pulmonary failure. Forty-nine percent (26/53) were successfully managed and survived to hospital discharge. The mean patient age was 5.0 +/- 8.6 months. Duration of mechanical ventilation before institution of extracorporeal life support was 8.1 +/- 6.2 days. Multivariate logistic regression analysis found four variables to be associated with patient nonsurvival at the p < 0.05 level: male gender, longer duration of mechanical ventilation before ECMO, higher peak inspiratory pressure, and lower ratio of arterial oxygen tension to fraction of inspired oxygen. Era of treatment was not associated with outcome. Receiver operator characteristic curve analysis of this multivariate model resulted in cutoff points of r = 0.5 and 0.1 that resulted in 92% sensitivity and 81% specificity (false-positive ratio 19%) and 96% sensitivity and 73% specificity (false-positive ratio 27%), respectively. CONCLUSIONS Predictors of outcome of severe respiratory failure caused by respiratory syncytial virus infection managed with ECMO exist, and multivariate predictive models with high sensitivity and low false-positive risk are possible. Similar mathematical models may be helpful in establishing criteria for future trials of ECMO versus conventional respiratory support.

Alveolar-arterial oxygen gradients before extracorporeal life support for severe pediatric respiratory failure: Improved outcome for extracorporeal life support-managed patients?

ObjectiveRecent reports have described the usefulness of the alveolar-arterial oxygen tension difference (P[A-a]o2) in predicting mortality in children with acute respiratory failure managed with mechanical ventilation. We reviewed our experience with extracorporeal life support for acute pediatric respiratory failure and specifically examined P(A-a)o2 measurements during the 24 hrs before extracorporeal life support to determine if defined cutoffs established with conventional mechanical ventilation were applicable to extracorporeal life-support survival. DesignRetrospective, case-series chart review. SettingA university tertiary medical center. PatientsInfants and children (n = 36), one month to 18 yrs of age, with severe life-threatening respiratory failure who were believed to have failed conventional mechanical ventilatory support. InterventionsVeno-venous or veno-arterial extracorporeal life support. Measurements and Main ResultsFrom 1982 to 1992, we managed 36 pediatric patients with severe respiratory failure using extracorporeal life support. We identified 28 patients who had P(A-a)o2 values of >400 torr (>53.3 kPa) for the 24-hr time period before placement on bypass.At the time of bypass initiation, all blood gas and mechanical ventilator parameters except Paco2 showed trends of worsening pulmonary function, compared with measurements done 24 hrs before bypass initiation. Oxygenation-related variables showed statistically significant worsening trends when measured 24 hrs before bypass, compared with the time of bypass: P(A-a)o2 539 vs. 582 torr (71.9 vs. 77.6 kPa), p <.01; Pao2/FIO2 ratio 70 vs. 57 torr (9.3 vs. 7.6 kPa), p <.05; oxygenation index 32 vs. 47 cm H2O/torr, p <.01; and FIO2 0.94 vs. 0.98, p <.05. Sixty-one percent of extracorporeal life support-managed patients (17 of 28) survived their life-threatening respiratory illness to be discharged home. ConclusionsBased on previous reports of the utility of P(A-a)o2 measurements to predict mortality, our preliminary evidence suggests that extracorporeal life support results in 62% survival for pediatric respiratory failure patients predicted to have no chance of survival using conventional mechanical ventilation. Prospective, randomized trials of children with severe acute respiratory failure managed with mechanical ventilation vs. extracorporeal life support may be indicated. (Crit Care Med 1994; 22:620–625)

Chronic otitis media requiring ventilation tubes in tracheotomized ventilator dependent children

The occurrence of sinusitis and middle ear effusions has frequently been attributed to the obstruction of the sinus ostia and/or eustachian tube. In the intensive care unit setting, edema caused by the irritation from nasogastric, nasotracheal and orotracheal tubes has been associated with this pathology and has been responsible for occult sepsis in this population. Our investigation was performed to determine the risk of chronic otitis media with effusion necessitating myringotomy with tympanostomy tubes among tracheotomized, ventilator dependent children in a consecutive series of children admitted to our recently created stable ventilator unit. We retrospectively reviewed the medical records of all tracheotomized, chronically ventilator dependent children < 48 months of age who had been hospitalized in this unit from the initial opening in September 1990 to January 1993. Data collected consisted of patient demographics, gestational age, cognitive abilities, age at onset of mechanical ventilation, age at tracheostomy, age at myringotomy, presence of nasogastric and gastroenterostomy tubes and evidence of gastric-esophageal reflux. All children underwent a tracheostomy procedure subsequent to the onset of mechanical ventilation. Of these patients, 9/12 (75%) later required myringotomy with tympanostomy tube placement following the occurrence of chronic otitis media with effusion. Ventilation tubes for chronic otitis media with effusion were not required in 3 patients. Using a case control study design, we examined the need of myringotomy tubes for children requiring continuous mechanical ventilation versus those requiring night-time only ventilation. The risk of myringotomy tubes in the continuously ventilated group (9/9) was significantly greater than the risk in the intermittently ventilated group (0/3) P < 0.01.(ABSTRACT TRUNCATED AT 250 WORDS)

Lidocaine toxicity after subcutaneous infiltration in children undergoing cardiac catheterization

Abstract The administration of subcutaneous lidocaine as a local anesthetic is readily observed in dental, orthopedic, and minor surgical procedures as well as for the insertion of monitoring catheters. The use of any local anesthetic presents significant risk to the patient, and extreme caution should be exercised in its administration1. Significant complications resulting from lidocaine toxicity have been reported.2–5 However, it is not well recognized that an elevated serum lidocaine level may result from the subcutaneous infiltration of lidocaine. Although the guidelines for the subcutaneous infiltration of lidocaine are established for children, these recommendations are often exceeded. In our study of 10 sequential patients, we describe 2 cases of lidocaine toxicity that occurred in children undergoing cardiac catheterization. This study was designed to determine if elevated serum lidocaine levels could occur after subcutaneous infiltration in children.

Sleep-Disordered Breathing in Michigan: A Practice Pattern Survey

Objectives: This survey sought to determine whether self-professed sleep specialists in the State of Michigan show practice variations in the diagnosis and management of sleep-disordered breathing (SDB), and whether such variations occur between pulmonologists and neurologists. Methods: Questionnaires on practice volume and patterns during the prior 12 months were mailed to physician members of the Michigan Sleep Disorders Association (n = 119); 67 were completed and returned. Results: Respondents reported that they personally saw a median of 8 new patients each week for suspected SDB; estimates were that 86% of these patients were eventually confirmed to have SDB. Most patients (82%) had laboratory-based polysomnography after an initial clinic evaluation, and most (69%) of those treated for SDB received continuous positive airway pressure. However, practice patterns differed substantially among respondents, even when the analysis was limited to the 42 who reported board certification by the American Board of Sleep Medicine. For example, among all surveyed practices the likelihood that suspected SDB would be evaluated with a split-night diagnostic and treatment polysomnogram varied from 0 to 90%. The likelihood of SDB treatment with bilevel positive airway pressure varied from 0 to 50%, with automatically titrating devices from 0 to 100%, with surgery from 0 to 100% (0 to 50% among certified practitioners), and with oral appliances from 0 to 20%. The practice patterns of pulmonologists and neurologists did not differ significantly. Conclusion: Approaches to SDB vary widely in Michigan, though not according to clinician background in pulmonary medicine or neurology. A patient’s experience, in both assessment and treatment, could differ substantially based on which clinician is consulted.