Neurobehavioral Outcomes in Children After Out-of-Hospital Cardiac Arrest

OBJECTIVE

This study examined 12-month neurobehavioral outcomes in children who survived out-of-hospital cardiac arrest (OH-CA), were comatose after resuscitation, and were enrolled in a clinical trial to evaluate targeted temperature management to hypothermia (33.0°C) or normothermia (36.8°C) (Therapeutic Hypothermia after Pediatric Cardiac Arrest, Out-of-Hopsital [THAPCA-OH]; NCT00878644).

METHODS

Baseline functioning was assessed by caregiver responses on the Vineland Adaptive Behavior Scales-Second Edition (VABS-II) soon after OH-CA (based on functioning before OH-CA); children with broadly normal baseline functioning (VABS-II ≥70) were included in the THAPCA-OH primary outcome. VABS-II was completed again 12 months later. Then, face-to-face cognitive evaluations were completed. Analyses evaluated changes in VABS-II composite, domain, and subdomain scores and cognitive functioning at follow-up.

RESULTS

Ninety-six of 295 enrolled children were alive at 12 months; 87 of 96 had broadly normal baseline functioning (VABS-II ≥70). Follow-up was obtained on 85/87. Forty-two of 85 had VABS-II ≥70 at 12 months. VABS-II composite, domain, and subdomain scores declined significantly between baseline and 12-month follow-up (P < .001). Declines were greatest in older children. Most children displayed well below average cognitive functioning. Older age at cardiac arrest and higher baseline VABS-II scores were predictive of greater decline in neurobehavioral function. Treatment with hypothermia did not influence neurobehavioral outcomes.

CONCLUSIONS

This is the largest study exploring long-term neurobehavioral outcomes in children surviving OH-CA who were comatose after resuscitation. Results revealed significant neurobehavioral morbidity across multiple functional domains, based both on caregiver reports and performance on objective cognitive measures, in survivors 1 year later.

Development and validation of the pediatric risk estimate score for children using extracorporeal respiratory support (Ped-RESCUERS)

PURPOSE

To develop and validate the Pediatric Risk Estimation Score for Children Using Extracorporeal Respiratory Support (Ped-RESCUERS). Ped-RESCUERS is designed to estimate the in-hospital mortality risk for children prior to receiving respiratory extracorporeal membrane oxygenation (ECMO) support.

METHODS

This study used data from an international registry of patients aged 29 days to less than 18 years who received ECMO support from 2009 to 2014. We divided the registry into development and validation datasets by calendar date. Candidate variables were selected for model inclusion if the variable independently changed the mortality risk by at least 2 % in a Bayesian logistic regression model with in-hospital mortality as the outcome. We characterized the model's ability to discriminate mortality with the area under curve (AUC) of the receiver operating characteristic.

RESULTS

From 2009 to 2014, 2458 non-neonatal children received ECMO for respiratory support, with a mortality rate of 39.8 %. The development dataset contained 1611 children receiving ECMO support from 2009 to 2012. The model included the following variables: pre-ECMO pH, pre-ECMO arterial partial pressure of carbon dioxide, hours of intubation prior to ECMO support, hours of admission at ECMO center prior to ECMO support, ventilator type, mean airway pressure, pre-ECMO use of milrinone, and a diagnosis of pertussis, asthma, bronchiolitis, or malignancy. The validation dataset included 438 children receiving ECMO support from 2013 to 2014. The Ped-RESCUERS model from the development dataset had an AUC of 0.690, and the validation dataset had an AUC of 0.634.

CONCLUSIONS

Ped-RESCUERS provides a novel measure of pre-ECMO mortality risk. Future studies should seek external validation and improved discrimination of this mortality prediction tool.

Therapeutic hypothermia after out-of-hospital cardiac arrest in children

BACKGROUND

Therapeutic hypothermia is recommended for comatose adults after witnessed out-of-hospital cardiac arrest, but data about this intervention in children are limited.

METHODS

We conducted this trial of two targeted temperature interventions at 38 children's hospitals involving children who remained unconscious after out-of-hospital cardiac arrest. Within 6 hours after the return of circulation, comatose patients who were older than 2 days and younger than 18 years of age were randomly assigned to therapeutic hypothermia (target temperature, 33.0°C) or therapeutic normothermia (target temperature, 36.8°C). The primary efficacy outcome, survival at 12 months after cardiac arrest with a Vineland Adaptive Behavior Scales, second edition (VABS-II), score of 70 or higher (on a scale from 20 to 160, with higher scores indicating better function), was evaluated among patients with a VABS-II score of at least 70 before cardiac arrest.

RESULTS

A total of 295 patients underwent randomization. Among the 260 patients with data that could be evaluated and who had a VABS-II score of at least 70 before cardiac arrest, there was no significant difference in the primary outcome between the hypothermia group and the normothermia group (20% vs. 12%; relative likelihood, 1.54; 95% confidence interval [CI], 0.86 to 2.76; P=0.14). Among all the patients with data that could be evaluated, the change in the VABS-II score from baseline to 12 months was not significantly different (P=0.13) and 1-year survival was similar (38% in the hypothermia group vs. 29% in the normothermia group; relative likelihood, 1.29; 95% CI, 0.93 to 1.79; P=0.13). The groups had similar incidences of infection and serious arrhythmias, as well as similar use of blood products and 28-day mortality.

CONCLUSIONS

In comatose children who survived out-of-hospital cardiac arrest, therapeutic hypothermia, as compared with therapeutic normothermia, did not confer a significant benefit in survival with a good functional outcome at 1 year. (Funded by the National Heart, Lung, and Blood Institute and others; THAPCA-OH ClinicalTrials.gov number, NCT00878644.).

Rationale, timeline, study design, and protocol overview of the therapeutic hypothermia after pediatric cardiac arrest trials

OBJECTIVE

To describe the rationale, timeline, study design, and protocol overview of the Therapeutic Hypothermia after Pediatric Cardiac Arrest trials.

DESIGN

Multicenter randomized controlled trials.

SETTING

Pediatric intensive care and cardiac ICUs in the United States and Canada.

PATIENTS

Children from 48 hours to 18 years old, who have return of circulation after cardiac arrest, who meet trial eligibility criteria, and whose guardians provide written consent.

INTERVENTIONS

Therapeutic hypothermia or therapeutic normothermia.

MEASUREMENTS AND MAIN RESULTS

From concept inception in 2002 until trial initiation in 2009, 7 years were required to plan and operationalize the Therapeutic Hypothermia after Pediatric Cardiac Arrest trials. Two National Institute of Child Health and Human Development clinical trial planning grants (R21 and R34) supported feasibility assessment and protocol development. Two clinical research networks, Pediatric Emergency Care Applied Research Network and Collaborative Pediatric Critical Care Research Network, provided infrastructure resources. Two National Heart Lung Blood Institute U01 awards provided funding to conduct separate trials of in-hospital and out-of-hospital cardiac arrest. A pilot vanguard phase that included half the clinical sites began on March 9, 2009, and this was followed by full trial funding through 2015.

CONCLUSIONS

Over a decade will have been required to plan, design, operationalize, and conduct the Therapeutic Hypothermia after Pediatric Cardiac Arrest trials. Details described in this report, such as participation of clinical research networks and clinical trial planning grants utilization, may be of utility for individuals who are planning investigator-initiated, federally supported clinical trials.

Early oxygenation and ventilation measurements after pediatric cardiac arrest: lack of association with outcome

OBJECTIVES

To explore oxygenation and ventilation status early after cardiac arrest in infants and children. We hypothesize that hyperoxia is common and associated with worse outcome after pediatric cardiac arrest.

DESIGN

Retrospective cohort study.

SETTING

Fifteen hospitals within the Pediatric Emergency Care Applied Research Network.

PATIENTS

Children who suffered a cardiac arrest event and survived for at least 6 hours after return of circulation.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Analysis of 195 events revealed that abnormalities in oxygenation and ventilation are common during the initial 6 hours after pediatric cardiac arrest. Hyperoxia was frequent, affecting 54% of patients. Normoxia was documented in 34% and hypoxia in 22% of patients. These percentages account for a 10% overlap of patients who had both hyperoxia and hypoxia. Ventilation status was more evenly distributed with hyperventilation observed in 38%, normoventilation in 29%, and hypoventilation in 46%, with a 13% overlap of patients who had both hyperventilation and hypoventilation. Derangements in both oxygenation and ventilation were common early after cardiac arrest such that both normoxia and normocarbia were documented in only 25 patients (13%). Neither oxygenation nor ventilation status was associated with outcome. After controlling for potential confounders, arrest location and rhythm were significantly associated with worse outcome; however, hyperoxia was not (odds ratio for good outcome, 1.02 [0.46, 2.84]; p = 0.96).

CONCLUSIONS

Despite recent resuscitation guidelines that advocate maintenance of normoxia and normoventilation after pediatric cardiac arrest, this is uncommonly achieved in practice. Although we did not demonstrate an association between hyperoxia and worse outcome, the small proportion of patients kept within normal ranges limited our power. Preclinical data suggesting potential harm with hyperoxia remain compelling, and further investigation, including prospective, large studies involving robust recording of physiological derangements, is necessary to further advance our understanding of this important topic.

Fatal and near-fatal asthma in children: the critical care perspective

OBJECTIVE

To characterize the clinical course, therapies, and outcomes of children with fatal and near-fatal asthma admitted to pediatric intensive care units (PICUs).

STUDY DESIGN

This was a retrospective chart abstraction across the 8 tertiary care PICUs of the Collaborative Pediatric Critical Care Research Network (CPCCRN). Inclusion criteria were children (aged 1-18 years) admitted between 2005 and 2009 (inclusive) for asthma who received ventilation (near-fatal) or died (fatal). Data collected included medications, ventilator strategies, concomitant therapies, demographic information, and risk variables.

RESULTS

Of the 261 eligible children, 33 (13%) had no previous history of asthma, 218 (84%) survived with no known complications, and 32 (12%) had complications. Eleven (4%) died, 10 of whom had experienced cardiac arrest before admission. Patients intubated outside the PICU had a shorter duration of ventilation (median, 25 hours vs 84 hours; P < .001). African-Americans were disproportionately represented among the intubated children and had a shorter duration of intubation. Barotrauma occurred in 15 children (6%) before admission. Pharmacologic therapy was highly variable, with similar outcomes.

CONCLUSION

Of the children ventilated in the CPCCRN PICUs, 96% survived to hospital discharge. Most of the children who died experienced cardiac arrest before admission. Intubation outside the PICU was correlated with shorter duration of ventilation. Complications of barotrauma and neuromyopathy were uncommon. Practice patterns varied widely among the CPCCRN sites.

Critical care for pediatric asthma: wide care variability and challenges for study

OBJECTIVES

To describe pediatric severe asthma care, complications, and outcomes to plan for future prospective studies by the Collaborative Pediatric Critical Care Research Network.

DESIGN

Retrospective cohort study.

SETTING

: Pediatric intensive care units in the United States that submit administrative data to the Pediatric Health Information System.

PATIENTS

Children 1-18 yrs old treated in a Pediatric Health Information System pediatric intensive care unit for asthma during 2004-2008.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Thirteen-thousand five-hundred fifty-two children were studied; 2,812 (21%) were treated in a Collaborative Pediatric Critical Care Research Network and 10,740 (79%) were treated in a non-Collaborative Pediatric Critical Care Research Network pediatric intensive care unit. Medication use in individual Collaborative Pediatric Critical Care Research Network centers differed widely: ipratropium bromide (41%-84%), terbutaline (11%-74%), magnesium sulfate (23%-64%), and methylxanthines (0%-46%). Complications including pneumothorax (0%-0.6%), cardiac arrest (0.2%-2%), and aspiration (0.2%-2%) were rare. Overall use of medical therapies and complications at Collaborative Pediatric Critical Care Research Network centers were representative of pediatric asthma care at non-Collaborative Pediatric Critical Care Research Network pediatric intensive care units. Median length of pediatric intensive care unit stay at Collaborative Pediatric Critical Care Research Network centers was 1 to 2 days and death was rare (0.1%-3%). Ten percent of children treated at Collaborative Pediatric Critical Care Research Network centers received invasive mechanical ventilation compared to 12% at non-Collaborative Pediatric Critical Care Research Network centers. Overall 44% of patients who received invasive mechanical ventilation were intubated in the pediatric intensive care unit. Children intubated outside the pediatric intensive care unit had significantly shorter median ventilation days (1 vs. 3), pediatric intensive care unit days (2 vs. 4), and hospital days (4 vs. 7) compared to those intubated in the pediatric intensive care unit. Among children who received mechanical respiratory support, significantly more (41% vs. 25%) were treated with noninvasive ventilation and significantly fewer (41% vs. 58%) were intubated before pediatric intensive care unit care when treated in a Pediatric Health Information System hospital emergency department.

CONCLUSIONS

Marked variations in medication therapies and mechanical support exist. Death and other complications were rare. More than half of patients treated with mechanical ventilation were intubated before pediatric intensive care unit care. Site of respiratory mechanical support initiation was associated with length of stay.

Multicenter cohort study of out-of-hospital pediatric cardiac arrest

OBJECTIVES

To describe a large cohort of children with out-of-hospital cardiac arrest with return of circulation and to identify factors in the early postarrest period associated with survival. These objectives were for planning an interventional trial of therapeutic hypothermia after pediatric cardiac arrest.

METHODS

A retrospective cohort study was conducted at 15 Pediatric Emergency Care Applied Research Network clinical sites over an 18-month study period. All children from 1 day (24 hrs) to 18 yrs of age with out-of-hospital cardiac arrest and a history of at least 1 min of chest compressions with return of circulation for at least 20 mins were eligible.

MEASUREMENTS AND MAIN RESULTS

One hundred thirty-eight cases met study entry criteria; the overall mortality was 62% (85 of 138 cases). The event characteristics associated with increased survival were as follows: weekend arrests, cardiopulmonary resuscitation not ongoing at hospital arrival, arrest rhythm not asystole, no atropine or NaHCO3, fewer epinephrine doses, shorter duration of cardiopulmonary resuscitation, and drowning or asphyxial arrest event. For the 0- to 12-hr postarrest return-of-circulation period, absence of any vasopressor or inotropic agent (dopamine, epinephrine) use, higher lowest temperature recorded, greater lowest pH, lower lactate, lower maximum glucose, and normal pupillary responses were all associated with survival. A multivariate logistic model of variables available at the time of arrest, which controlled for gender, age, race, and asystole or ventricular fibrillation/ventricular tachycardia anytime during the arrest, found the administration of atropine and epinephrine to be associated with mortality. A second model using additional information available up to 12 hrs after return of circulation found 1) preexisting lung or airway disease; 2) an etiology of arrest drowning or asphyxia; 3) higher pH, and 4) bilateral reactive pupils to be associated with lower mortality. Receiving more than three doses of epinephrine was associated with poor outcome in 96% (44 of 46) of cases.

CONCLUSIONS

Multiple factors were identified as associated with survival after out-of-hospital pediatric cardiac arrest with the return of circulation. Additional information available within a few hours after the return of circulation may diminish outcome associations of factors available at earlier times in regression models. These factors should be considered in the design of future interventional trials aimed to improve outcome after pediatric cardiac arrest.

Multicenter cohort study of in-hospital pediatric cardiac arrest

OBJECTIVES

1) To describe clinical characteristics, hospital courses, and outcomes of a cohort of children cared for within the Pediatric Emergency Care Applied Research Network who experienced in-hospital cardiac arrest with sustained return of circulation between July 1, 2003 and December 31, 2004, and 2) to identify factors associated with hospital mortality in this population. These data are required to prepare a randomized trial of therapeutic hypothermia on neurobehavioral outcomes in children after in-hospital cardiac arrest.

DESIGN

Retrospective cohort study.

SETTING

Fifteen children's hospitals associated with Pediatric Emergency Care Applied Research Network.

PATIENTS

Patients between 1 day and 18 years of age who had cardiopulmonary resuscitation and received chest compressions for >1 min, and had a return of circulation for >20 mins.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A total of 353 patients met entry criteria; 172 (48.7%) survived to hospital discharge. Among survivors, 132 (76.7%) had good neurologic outcome documented by Pediatric Cerebral Performance Category scores. After adjustment for age, gender, and first documented cardiac arrest rhythm, variables available before and during the arrest that were independently associated with increased mortality included pre-existing hematologic, oncologic, or immunologic disorders, genetic or metabolic disorders, presence of an endotracheal tube before the arrest, and use of sodium bicarbonate during the arrest. Variables associated with decreased mortality included postoperative cardiopulmonary resuscitation. Extending the time frame to include variables available before, during, and within 12 hours following arrest, variables independently associated with increased mortality included the use of calcium during the arrest. Variables associated with decreased mortality included higher minimum blood pH and pupillary responsiveness.

CONCLUSIONS

Many factors are associated with hospital mortality among children after in-hospital cardiac arrest and return of circulation. Such factors must be considered when designing a trial of therapeutic hypothermia after cardiac arrest in pediatric patients.

In-hospital versus out-of-hospital pediatric cardiac arrest: a multicenter cohort study

OBJECTIVES

: To describe a large multicenter cohort of pediatric cardiac arrest (CA) with return of circulation (ROC) from either the in-hospital (IH) or the out-of-hospital (OH) setting and to determine whether significant differences related to pre-event, arrest event, early postarrest event characteristics, and outcomes exist that would be critical in planning a clinical trial of therapeutic hypothermia (TH).

DESIGN

: Retrospective cohort study.

SETTING

: Fifteen Pediatric Emergency Care Applied Research Network sites.

PATIENTS

: Patients aged 24 hours to 18 years with either IH or OH CA who had a history of at least 1 minute of chest compressions and ROC for at least 20 minutes were eligible.

INTERVENTIONS

: None.

MEASUREMENTS AND MAIN RESULTS

: A total of 491 patients met study entry criteria with 353 IH cases and 138 OH cases. Major differences between the IH and OH cohorts were observed for patient prearrest characteristics, arrest event initial rhythm described, and arrest medication use. Several postarrest interventions were used differently, however, the use of TH was similar (<5%) in both cohorts. During the 0-12-hour interval following ROC, OH cases had lower minimum temperature and pH, and higher maximum serum glucose recorded. Mortality was greater in the OH cohort (62% vs. 51%, p = 0.04) with the cause attributed to a neurologic indication much more frequent in the OH than in the IH cohort (69% vs. 20%; p < 0.01).

CONCLUSIONS

: For pediatric CA with ROC, several major differences exist between IH and OH cohorts. The finding that the etiology of death was attributed to neurologic indications much more frequently in OH arrests has important implications for future research. Investigators planning to evaluate the efficacy of new interventions, such as TH, should be aware that the IH and OH populations differ greatly and require independent clinical trials.

Continuous quality improvement: reducing unplanned extubations in a pediatric intensive care unit

OBJECTIVE

Unplanned extubation (UEX) is a potentially serious complication of mechanical ventilation. Limited information is available regarding factors that contribute to UEXs and subsequent reintubation of children. We monitored UEXs in our pediatric intensive care unit (PICU) for a 5-year period to assess the incidence and patient conditions associated with UEX and to evaluate whether targeted interventions were associated with a reduced rate of UEXs.

METHODS

Over a 5-year period, demographic and clinical information was collected prospectively on all patients who required an artificial airway while admitted to the PICU. Additional information was collected for patients who experienced an UEX. Educational sessions and care management protocols were developed, implemented, and modified according to issues identified via the monitoring program.

RESULTS

From a total of 2192 patients who required 13 630 airway days (AWD), 141 (6%) patients experienced 164 UEXs. The overall rate of UEX for the study period was 1.2 UEXs per 100 AWD, and this rate decreased from 1.5 in the first year to 0.8 in the last year. UEXs were more common in children who were younger than 5 years (1.6 vs 0.6 UEX per 100 AWD) compared with older children. The UEX children experienced significantly longer length of mechanical ventilation (6 vs 3 days) and longer length of PICU stay (8 vs 4 days) compared with non-UEX children. Forty-six percent of the UEXs occurred in patients who were weaning from mechanical ventilation, and 22% of those patients required reintubation.

CONCLUSIONS

We conclude that UEX in pediatric patients is associated with longer length of mechanical ventilation and length of stay in the PICU. A continuous quality improvement monitoring and educational program that identified high-risk patients for UEX (younger patients) and patients who were at low risk for subsequent reintubation (weaning patients) contributed to a reduction of these potentially adverse events.

Outcome of pediatric patients treated with extracorporeal life support after cardiac surgery

BACKGROUND

Extracorporeal life support (ECLS) has been used for over two decades in select patients after cardiac surgery. We previously described factors associated with death in this population. We now review our recent experience to reassess factors related to mortality.

METHODS

All pediatric patients who received ECLS support within 7 days after surgery between July 1995 and June 2001 were examined to describe clinical features associated with survival. We compared the results with our prior report to assess changes in practice and outcome.

RESULTS

Seventy-four patients were followed. Fifty percent survived to discharge. Hospital survival was not significantly related to patient age, cannulation site, or indication. Thirty-five percent of patients required hemofiltration while on ECLS and were significantly less likely to survive (23% vs 65%). A multivariate analysis combining all children from our prior report with the present cohort revealed that patients who received hemofiltration were five times more likely to die (odds ratio 5.01, 95% confidence interval 2.11-11.88). Children with an adequate two-ventricular repair had lower risk of death (odds ratio 0.42, 95% confidence interval 0.19-0.91) after adjusting for patient age, study period, and hours elapsed before initiation of ECLS after surgery.

CONCLUSIONS

Patients with an adequate two-ventricle repair have significantly higher hospital survival, whereas those with single ventricle physiology or need for dialysis have decreased survival.

Nosocomial catheter-related bloodstream infections in a pediatric intensive care unit: risk and rates associated with various intravascular technologies

OBJECTIVE

Nosocomial bloodstream infections are associated with increased patient morbidity, mortality, and hospital costs. More than 90% of these infections are related to the use of intravascular catheter devices. This study was done to assess the risk and rates of catheter related-bloodstream infections (CR-BSI) associated with different intravascular technologies in a pediatric intensive care unit population.

DESIGN

Retrospective cohort study.

SETTING

A 16-bed pediatric intensive care unit in a tertiary children's hospital.

STUDY POPULATION

All admissions between July 1997 and December 1999 requiring placement of an intravascular access device for care were examined. Patients with CR-BSI were identified through ongoing surveillance using Centers for Disease Control/National Nosocomial Infections Surveillance System definitions for bloodstream infection.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Of the 2,728 admissions during the review period, 1,043 (38.3%) required placement of an intravascular access device. Bivariate analysis revealed that patients who required intravascular cannulae for extracorporeal life support had a 10-fold increased risk of developing a CR-BSI, and patients requiring vascular access for renal replacement therapy demonstrated a 4-fold increase in the risk of developing CR-BSI compared with the referent group. There was a significant increase in the CR-BSI rate associated with the use of more intravascular access devices per patient admission. Multivariate logistic regression identified the use of extracorporeal life support therapy and the total duration of use of intravascular access devices as significant independent predictors of CR-BSI when controlling for other predictors.

CONCLUSION

The use of extracorporeal life support therapy, the presence of multiple intravascular access devices, and the total duration of intravascular access device use were associated with an increase in the rate and risk of developing CR-BSI in our pediatric intensive care unit population. Larger, prospective studies may help elucidate additional factors responsible for these observations.

Use of extracorporeal life support as a bridge to pediatric cardiac transplantation

BACKGROUND

Extracorporeal life support (ECLS) has been used for post-cardiotomy rescue, but its use as a bridge to heart transplantation (OHT) in patients with post-surgical or end-stage ventricular failure remains controversial.

METHODS

Records were reviewed for patients receiving ECLS for ventricular failure from January 1991 to August 2001. Patients listed for OHT were analyzed separately. Listing for OHT requirements were improbable myocardial recovery, absence of contraindications (central nervous system damage, high pulmonary resistance, ongoing infection, etc.), and parental consent. Outcome variables included patient demographics, diagnosis, days from ECLS initiation to United Network for Organ Sharing (UNOS) listing (latency), list time, renal function, and survival to discharge.

RESULTS

Of 145 patients with ventricular failure who received ECLS, 21 pediatric patients were UNOS listed. Of 124 non-listed patients, 57 (46%) survived to discharge. All but 3 survivors were separated from ECLS in </=7 days. Twelve underwent OHT and 10 survived to discharge (list time, 6 days; median ECLS time, 14 days). Five had ECLS discontinued without undergoing OHT (1 later underwent OHT, 2 survived to discharge). Five experienced complications while receiving ECLS and died without undergoing OHT. Six of 9 patients who required dialysis for renal failure died. Of 11 infants listed, 4 were weaned from ECLS without undergoing OHT (2 survived to discharge), 5 had OHT (ECLS support, 4 days; 4 survived to discharge) and 2 died (ECLS support, 16 and 47 days).

CONCLUSIONS

(1) Extracorporeal life support can be used as a bridge to OHT (even among the infant population) for at least 2 weeks with acceptable survival and hospital discharge rates, and (2) renal insufficiency with the concomitant requirement for dialysis decreases the likelihood of survival before and after OHT.

Pediatric Extracorporeal Life Support After High Frequency Ventilation: Predictors of Survival

Previous studies of extracorporeal life support in pediatric patients have identified variables associated with survival. However, none of these studies focused on extracorporeal life support after failure of high frequency ventilation (HFV). In the present study, we determined variables associated with survival for pediatric respiratory failure patients who received HFV prior to extracorporeal life support, using data reported to the Extracorporeal Life Support Organization Registry from 1992 to 1998. Patients with neonatal diagnoses, immune compromising conditions, or congenital cardiac defects were excluded. The 243 patients who met inclusion criteria had a 58% survival rate (95% CI 48-66%). The mean age was 22 +/- 39 months. Mean duration of mechanical ventilation prior to extracorporeal life support was 6.6 +/- 5.8 days. Venoarterial extracorporeal life support was used in 72% of the patients; venovenous in 28%. The survival rate for the subset of patients with an oxygenation index greater than 42 cm H2O/torr on HFV (n = 122) was not significantly different from the overall sample. We determined that lower mean airway pressure, lower pressure amplitude, decreased oxygenation index, increased PaO2, and increased oxygen saturation on HFV were associated with increased survival in patients who were subsequently treated with extracorporeal life support.

Cisatracurium infusion for neuromuscular blockade in the pediatric intensive care unit: A dose-finding study

OBJECTIVE: To evaluate the safety and efficacy of cisatracurium besylate, a neuromuscular blocking agent in infants zero to 2 yrs of age. DESIGN: An open-label study to evaluate efficacy and safety of cisatracurium as a continuous infusion in infants. SETTING: A tertiary pediatric intensive care unit. PATIENTS: Eleven children, 0-2 yrs of age, requiring prolonged neuromuscular blockade. INTERVENTIONS: Cisatracurium besylate, 0.1 mg/kg, was administered as an intravenous bolus dose and repeated if necessary until a >90% neuromuscular blockade, as determined by train-of-four response, was achieved. Patients were allowed to recover to 90% blockade (I/IV twitch) after the initial bolus and were administered continuous infusion at 2 &mgr;g/kg/min. The continuous infusion rate was adjusted to maintain a train-of-four response of 0-I/IV, with an increase in the rate preceded by a bolus dose of cisatracurium besylate. An electromyographic monitor was used to measure recovery at the end of infusion, when possible. Heart rate and blood pressure were recorded after the initial bolus dose and after changes in infusion rates. Blood samples were drawn at steady-state during cisatracurium infusion at several different times during the study and at the end of infusion for measurement of plasma cisatracurium and laudanosine concentrations. MEASUREMENTS AND MAIN RESULTS: The mean infusion rate of cisatracurium besylate required to maintain train-of-four response of 0-I/iv was 5.4 +/- 3.0 &mgr;g/kg/min. The mean total duration of infusion was 64.5 +/- 36 hrs. Ten percent and complete neuromuscular recovery occurred at 26.6 +/- 10.4 and 74.8 +/- 32 mins, respectively, after discontinuation of infusion. Mean cisatracurium and laudanosine concentrations were 342.5 +/- 169 and 163.3 +/- 116 ng/mL, respectively. Four (37%) patients had undetectable (<5 ng/mL) cisatracurium concentrations at the time of 100% neuromuscular recovery (train-of-four response of IV/IV or no fade at 50 mA on the electromyogram). No significant hemodynamic changes were observed during treatment with cisatracurium besylate (p <.05). CONCLUSIONS: A longer period of recovery from neuromuscular blockade was observed compared with reports of older children. Recovery from neuromuscular blockade after long-term use was not associated with any adverse events in the immediate postinfusion period. Cisatracurium besylate is a safe and effective neuromuscular blocking agent for children 0-2 yrs of age.

Extracorporal life support for pulmonary hemorrhage in children: a case series

OBJECTIVE

To examine the use and outcome of extracorporeal life support in children with severe respiratory failure caused by pulmonary hemorrhage.

DESIGN

Retrospective case series report.

SETTING

Pediatric intensive care unit in a university children's hospital.

PATIENTS

Eight patients <19 yrs of age who required extracorporeal life support for severe respiratory failure associated with pulmonary hemorrhage.

INTERVENTIONS

Venoarterial or venovenous extracorporeal life support.

MEASUREMENTS

Ventilatory support parameters and systemic PaO2/FiO2 ratio before extracorporeal life support, time on extracorporeal life support, number of ventilator days, number of intensive care unit days, number of hospital days, continued bleeding on extracorporeal life support, and survival.

MAIN RESULTS

All patients had resolution of their pulmonary hemorrhage within 24 hrs. All patients survived to decannulation, extubation, and hospital discharge. All patients are alive, with follow-up times ranging from 1 to 10 yrs.

CONCLUSIONS

Extracorporeal life support is not contraindicated in patients with severe respiratory failure with associated pulmonary hemorrhage and may be a life-sustaining supportive therapy.

Efficacy of recombinant human deoxyribonuclease I in the hospital management of respiratory syncytial virus bronchiolitis

OBJECTIVE

To evaluate the effect of recombinant human deoxyribonuclease I (rhDNase) in shortening the length of the hospitalization and improving the chest radiographs (CXRs) in hospitalized infants with respiratory syncytial virus (RSV) infection as a result of its mucolytic properties.

METHODS

Randomized, double-blind, placebo-controlled investigation of 75 patients with RSV bronchiolitis. The study was conducted at the University of Michigan Medical Center and St. Joseph Mercy Hospital, both in Ann Arbor, MI.

RESULTS

The respiratory rate, wheezing, and retraction difference scores, obtained by subtracting the hospital discharge score from the corresponding hospital admission score, show no difference between the two groups, but the CXR difference scores show that the rhDNase group improved by 0.46 while the placebo group worsened by 0.60 (p < 0.001). Analysis of covariance for the hospital discharge CXR score after adjusting for the hospital admission score for both groups was done. There was a difference in scores between the two groups, with adjusted mean for the study group of 2.03, and 2.76 for the placebo group (p < 0.001). Paired t test statistics in each of the two groups were computed. For the placebo group, the mean increase of 0.60 was significant (p = 0.02), and the mean decrease of 0.46 for the rhDNase group was also significant (p = 0.02). A one-way analysis of covariance with the hospital discharge CXR scores as the dependent variable and the hospital admission score as the covariate showed that there was a significant difference between the groups (p = 0.01).

CONCLUSION

In patients with RSV bronchiolitis, there was significant improvement in the CXRs with the use of rhDNase compared to significant worsening in the placebo group. To our knowledge, this is the first report of the use of rhDNase to treat RSV bronchiolitis.

Venovenous versus venoarterial extracorporeal life support for pediatric respiratory failure: are there differences in survival and acute complications?

OBJECTIVES

To examine the Extracorporeal Life Support Organization (ELSO) registry database of infants and children with acute respiratory failure to compare outcome and complications of venovenous (VV) vs. venoarterial (VA) Extracorporeal Life Support (ECLS).

DESIGN

Retrospective cohort study.

SETTING

ELSO registry for pediatric pulmonary support.

PATIENTS

All nonneonatal pediatric pulmonary support ECLS cases treated at U.S. centers and reported to the ELSO registry as of July 1997. Patients were excluded if they had one or more of the following diagnoses: hematologic-oncologic, cardiac, abdominal surgical, burn, metabolic, airway, or immunodeficiency disorder.

INTERVENTIONS

Venoarterial or venovenous extracorporeal life support for severe pulmonary failure.

MEASUREMENTS AND MAIN RESULTS

From 1986 to June of 1997, 763 pediatric patients met the inclusion criteria. Overall, 595 were initially managed with VA bypass, and 168 with VV bypass. The VA group was younger (mean +/- SD, 26.1+/-42.2 months for VA vs. 63.5+/-68.7 months for VV) and smaller (11.8+/-15.1 kg vs. 22.9+/-23.8 kg) (p<.001). There were no differences between groups in number of days on mechanical ventilation before ECLS, number of hours on ECLS, or number of hours on mechanical ventilation post-ECLS in survivors. Mean pH and Paco2 values, positive end-expiratory pressure, and mean airway pressure just before placing the patient on ECLS were also similar. VA-treated patients had higher Fio2 requirements (p = .034), lower Pao2 (p = .047), and lower Pao2/Fio2 ratio (p = .014) just before cannulation. There was a trend of higher peak inspiratory pressure in VA-treated patients (p = .053). Overall, survival rate was not different for the two groups (55.8% for VA vs. 60.1% for VV; p = .33). Central nervous system complications were not different between the two groups. Examination of the same variables was then conducted after dividing the patients into four subgroups. There were no significant differences in survival or complications during bypass between VV and VA modes of ECLS in any subgroup. Stepwise logistic regression modeling was performed to control for variables associated with the outcome survival for VV and VA-treated groups, and variables measured before bypass were identified as being associated with improved survival. There was a trend of improved survival in the VV-treated patients (p = .12).

CONCLUSIONS

Overall survival of pediatric patients with acute respiratory failure supported by VA or VV ECLS was comparable. A randomized clinical trial may be useful in clarifying these observations.

Severity of illness models for respiratory syncytial virus-associated hospitalization

The objective of this investigation was to examine the feasibility of multivariate severity of illness models for pediatric patients hospitalized with respiratory syncytial virus (RSV) infection. From a preexisting retrospective cohort study database, all infants and children 2 yr of age or younger with community-acquired RSV infection admitted to the University of Michigan's C. S. Mott Children's Hospital during nine epidemics were examined. The study group consisted of 802 hospitalized patients younger than 2 yr of age with community-acquired RSV infection; 182 (23%) patients had prolonged hospital length of stay defined as 7 d or greater. Multivariate logistic regression modeling of nine variables measurable during the first hospital day was strongly associated with prolonged hospitalization (p < 0.0001). Receiver operator characteristic curve analysis resulted in an area under the curve of 0.894, indicating excellent model discrimination. Goodness-of-fit testing indicated excellent model calibration for observed versus predicted outcomes (p = 0.216). We conclude that severity of illness models for RSV-associated hospitalization with excellent predictive properties in terms of classification, discrimination, and calibration are possible. Further study is required to determine if such models are generalizable across multiple centers and epidemics.