Hemodialysis followed by continuous hemofiltration for treatment of lithium intoxication in children.

Hemodialysis is the usual recommended treatment for severe lithium intoxication; however, rebound of lithium levels may require repeated hemodialysis treatments. We proposed that the addition of continuous hemofiltration after hemodialysis would prevent rebound by providing ongoing clearance of lithium. We report two pediatric patients with lithium intoxication treated by hemodialysis followed by continuous venovenous hemofiltration with dialysis (CVVHD). Both patients were symptomatic at presentation and had initial lithium levels more than three times the usual therapeutic range. Hemodialysis followed by CVVHD resulted in rapid resolution of symptoms, followed by continuous clearance of lithium without requiring repeated hemodialysis sessions. Both patients had return of normal mental status during CVVHD treatment, and neither patient experienced complications of hemodialysis or CVVHD. Total duration of treatment with hemodialysis followed by CVVHD was 34.5 hours for the first patient and 26 hours for the second patient. We conclude that hemodialysis followed by CVVHD is a safe and effective approach to the management of lithium intoxication in children.

Amino acid loss and nitrogen balance in critically ill children with acute renal failure: a prospective comparison between classic hemofiltration and hemofiltration with dialysis.

HYPOTHESIS: Amino acid (AA) loss is not equivalent on continuous venovenous hemofiltration (CVVH) compared with continuous venovenous hemodiafiltration (CVVHD). Amino acid supplementation may be necessary to adjust for a greater clearance on CVVH to maintain nitrogen balance similar to that of CVVHD. OBJECTIVE: To compare AA losses and nitrogen balance between CVVH and CVVHD in children with acute renal failure. SETTING: Pediatric patients in the pediatric intensive care unit of a tertiary referral center. DESIGN: Prospective randomized crossover study in consecutive children who required hemofiltration. PATIENTS: A total of 12 plasma clearance studies for AA and urea, consisting of 24-hr collections of ultrafiltrate and urine for nitrogen balance, was performed on six patients during CVVH and CVVHD. Patients received total parenteral nutrition (TPN) with caloric intake 20% to 30% above their resting energy expenditure measured by indirect calorimetry and 1.5 g/kg/day protein of TPN. Study conditions were comprised of 2 L/hr/1.73 m2 of dialysate or prefiltered replacement fluid and hemofilter flow rates of 4 mL/kg/min were maintained for all patients. METHODS AND MAIN RESULTS: Amino acid clearances were greater on CVVH than CWHD, except for glutamic acid, where clearance was 6.73+/-2.31 (SEM) mL/min/1.73 m2 on CVVH and 7.59+/-2.79 mL/min/1.73 m2 for CVVHD (NS). The clearance difference between the two modalities was 30%. Urea clearance was equivalent (30.1+/-1.74 mL/min/1.73 m2 and 29.0+/-.97 mL/min/1.73 m2) for CVVH and CVVHD, respectively. Amino acid loss on CVVH and CVVHD was similar (12.50+/-1.29 g/day/1.73 m2 vs. 11.61+/-1.86 g/day/1.73 m2, respectively), representing 12% and 11%, respectively, of the daily protein intake. The catabolic state, as measured by urea nitrogen appearance, was high for all patients during the 48-hr study period with a mean of 291 mg/kg/day during CVVH, and 245 mg/kg/day for CVVHD. Nitrogen balance varied from a negative 12.95 g/day/1.73 m2 to a positive 4.93 g/day/1.73 m2 on CVVH and a negative 7.69 g/day/1.73 m2 to a positive 5.50 g/day/1.73 m2 on CVVHD. CONCLUSIONS: Clearance of AA is greater on CVVH than on CVVHD, but no significant difference in AA loss was present between the two therapies. Nitrogen balance often is not met on either therapy when a standard 1.5 g/kg/day protein and a resting energy expenditure of 120% to 130% of calories is delivered by TPN.

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.

Extracorporeal life support: the University of Michigan experience.

The University of Michigan experience with extracorporeal life support (ECLS) in 1000 consecutive patients between 1980 and 1998 is the largest series at one institution in the world. Among this patient population, survival to hospital discharge in moribund patients with respiratory failure was 88% in 586 neonates, 70% in 132 children, and 56% in 146 adults. Survival in moribund patients with cardiac failure was 48% in 105 children and 33% in 31 adults. This article describes the University of Michigan's overall ECLS patient experience, the progression of ECLS from laboratory experiments to clinical application at the bedside, the expansion of the technology to other centers, and current ECLS technology and outcomes. Despite the challenges faced in clinical research in this field, our experience and that of others has shown that ECLS saves lives of patients with acute cardiac or pulmonary failure in a variety of clinical settings.

Outcome-associated factors in pediatric patients treated with extracorporeal membrane oxygenator after cardiac surgery.

BACKGROUND: The use of the extracorporeal membrane oxygenator (ECMO) for postoperative cardiac patients has not resulted in the same high success rate as when ECMO is used for neonates with pulmonary hypertension or pulmonary failure. The reason for this is poorly understood. METHODS AND RESULTS: We analyzed retrospectively all pediatric patients placed on ECMO after surgery for a congenital heart lesion between 1981 and 1995 (n = 64). Patients had a two-ventricular repair (A) or pulmonary blood flow supplied by an aortopulmonary shunt (B) or by a cavopulmonary connection (C). Indication for ECMO was unsatisfactory hemodynamics due to (1) ventricular dysfunction, (2) pulmonary failure, (3) pulmonary hypertension, or (4) a combination or (5) for unclear reasons. Hospital survival was related to these and other factors. Overall hospital survival was 33%; 42% of group A patients survived to discharge, whereas only 25% and 17% survived in groups B and C, respectively. Survival was unrelated to the indication for ECMO but appeared to be lower when ECMO was initiated in the operating room or > 50 hours after surgery. Except for one patient with pneumonia, no patient survived who was on ECMO for > 208 hours. ECMO discontinuation in nonsurvivors was due to neurological (30%) or multiple complications (39%), the lack of return of cardiac function (12%), or other reasons (15%). CONCLUSIONS: This review suggests that the diagnosis of single ventricle, initiation of ECMO in the operating room or > 50 hours after surgery, and ECMO for > 208 hours are associated with patient nonsurvival. Noncardiac complications more frequently led to discontinuation of ECMO than did failure of the return of cardiac function.

Mechanical ventilation and arterial blood gas measurements 24 hours postextracorporeal life support for survivors of pediatric respiratory failure.

OBJECTIVE: To summarize our institutional experience concerning mechanical ventilation support and blood gas measurements in the 24-hr period following extracorporeal life support (ECLS) for pediatric acute respiratory failure. DESIGN: Descriptive study. SETTING: A tertiary pediatric referral center. PATIENTS: Children aged 1 month to 18 yrs treated with ECLS for acute respiratory failure at University of Michigan Hospitals from November 1982 to June 1993. All patients aged 1 month to 18 yrs who received ECLS for acute respiratory failure were included. Patients who received ECLS primarily for cardiac support or who had a diagnosis of congenital gastrointestinal malformation (i.e. congenital diaphragmatic hernia) were excluded. INTERVENTIONS: ECLS for severe pediatric respiratory failure. MEASUREMENTS AND MAIN RESULTS: Forty-nine children were treated at our center with ECLS for acute respiratory failure 36 (73%) survived. Ventilator settings immediately after decannulation from ECLS for survivors were as follows: FIO2 0.53 +/- 0.18 (SD); intermittent mandatory ventilation (IMV) 29.6 +/- 1.18 breaths/min, positive end-expiratory pressure 5.3 +/- 1.6 cm H2O, mean airway pressure 12.6 +/- 2.9 cm H2O, and peak inspiratory pressure 31.7 +/- 5.5 cm H2O. Arterial blood gas measurements at decannulation were PaO2 89.4 +/- 30.9 torr (11.9 +/- 4.1 kPa), PaCO2 43.7 +/- 9.7 torr (5.8 +/- 1.3 kPa), and pH 7.39 +/- 0.07. Twenty-four hours after decannulation, ventilator settings and arterial blood gas measurements were as follows: FIO2 0.42 +/- 0.14, IMV 27.4 +/- 13.5 breaths/min, positive end-expiratory pressure 5.2 +/- 1.6 cm H2O, mean airway pressure 12.0 +/- 3.4 cm H2O, peak inspiratory pressure 31.1 +/- 6.5 cm H2O, PaO2 77.0 +/- 16.9 torr (10.3 +/- 2.3 kPa), PaCO2 44.9 +/- 8.4 torr (6.0 +/- 1.1 kPa), and pH 7.40 +/- 0.07. Variables associated with oxygenation status (P[A-a]O2) and mean airway pressure (oxygenation index) improved during the immediate 24-hr period postbypass (p < .05). CONCLUSIONS: Successful decannulation from ECLS for > 24 hrs resulted in long-term survival in 97% (36/37) of children. Ventilator parameters and arterial blood gas measurements during the 24-hr period following bypass have been described for this population. Such conventional support may indicate safe levels of oxygen and mechanical ventilation pressures for the postbypass recovering lung.

Normalization of priming solution ionized calcium concentration improves hemodynamic stability of neonates receiving venovenous ECMO.

The authors' objectives in this investigation were: 1) to prospectively determine whether a normocalcemic priming solution would result in elimination of hypocalcemia after the initiation of extracorporeal membrane oxygenation (ECMO); 2) to investigate whether normocalcemia would result in improvements in the patient's hemodynamics during the initiation of ECMO; and 3) to further define the relationship between ionized calcium measurements and total calcium, serum total protein, serum albumin, and total magnesium. This was a prospective study done in our neonatal intensive care unit, and included nine neonatal patients placed on ECMO for cardiopulmonary support. The bypass circuit was primed in the standardized manner with 100 mg calcium chloride. Circuit ionized calcium measurements were performed, and additional calcium chloride was added to normalize the ionized calcium in the priming solution. Ionized calcium was measured from the circuit and the patient before the initiation of ECMO, and then again from the patient 5, 10, 15, 30, 60, 120, and 240 minutes after the initiation of ECMO. The patients' mean arterial pressure was measured simultaneously with each ionized calcium measurement. Ionized calcium, serum total calcium, total protein, serum albumin, and total magnesium were measured from blood samples simultaneously collected four times daily. There was no significant change in the ionized calcium measured in the patients after the initiation of ECMO. There was, however, a significant increase in blood pressure 5 min after the initiation of ECMO (62 +/- 7 mmHg vs 53 +/- 6 mmHg, p = 0.01). Thereafter, there was no difference in blood pressure measured when compared with pre ECMO values. A poor correlation was demonstrated between ionized calcium and total calcium (r2 = 0.35), serum total protein (r2 = 0.26), serum albumin (r2 = 0.27), and total magnesium (r2 = 0.05). On the basis of the authors' data, the initiation of ECMO with a normocalcemic prime results in a minimal change in patient ionized calcium and resolution of the hypotension previously observed. In addition, there was poor correction between ionized calcium, total calcium, and other indirect measures of ionized calcium. Ionized calcium measurements are critical for patient hemodynamic stability before bypass and should be normalized in both the patient and priming solution before the initiation of bypass.

Continuous venovenous hemodiafiltration in infants and children.

Continuous venovenous hemodiafiltration (CVVHD) is not commonly used in pediatric intensive care units due to the lack of suitable equipment needed for this technique of renal replacement therapy (RRT). We have used an adapted hemodialysis machine that includes a blood pump controller, an air leak detector, and a venous pressure monitor over the past year in the pediatric intensive care unit. Blood lines available for hemodialysis were used for CVVHD, limiting the extracorporeal circuit volume to 38 mL, which allows for CVVHD capability in an infant as small as 4.5 kg without a blood-primed circuit. We have compared this experience to previous continuous arteriovenous hemodiafiltration (CAVHD) at our institution. The two groups (CVVHD and CAVHD) were similar in age, weight, blood pressure, and indication for RRT. There was significantly less number of hemofilters used, an improved number of hours per hemofilter, and a significantly less change of RRT modality due to ineffective dialysis (CVVHD 0% v CAVHD 32%) when using CVVHD. Furthermore, an average of 48% less heparin was used in the CVVHD population. We conclude that CVVHD can be safely and effectively carried out in infants and small children with less heparinization, no need for arterial access, and less risk of ineffective RRT.

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)

Simulated pediatric cardiopulmonary resuscitation: initial events and response times of a hospital arrest team.

BACKGROUND: Cardiopulmonary resuscitation (CPR) training programs exist to enhance knowledge and skills retention. However, they do not ensure that effective CPR will be performed by trainees or resuscitation teams. One aspect of CPR effectiveness is the ability of the team to respond to an emergency call in a timely manner. METHODS: We prospectively evaluated the time required for team members to respond to an emergency call and to initiate definitive treatment in our pediatric facility. The medical staff who responded had no prior knowledge of the simulated cardiac arrest (SCA) events. All events were recorded on audio-cassette tape to determine the sequence of events and response time of arrest team members. SCA scenarios represented examples of cardiac, hematologic, renal, respiratory, and pharmacologic pathophysiology. All participants were instructed to respond as though the SCA were an actual emergency. RESULTS: From December 1991 to January 1993, 37 SCAs were evaluated. Documentation began after a concise arrest scenario had been presented to a designated nursing representative who was to be the first rescuer on the scene. The rescuer first assessed the patient's condition, activated the cardiac arrest system (median elapsed time, MET, 0.50 minutes), and then initiated single-person CPR (MET 0.58 minutes). Administration of oxygen occurred at an MET of 2.25 minutes. The first member of the arrest team to respond was the pediatric resident (MET 3.17 minutes) followed by the respiratory therapist (MET 3.20 minutes), an ICU nurse (MET 3.58 minutes), a pharmacist (MET 3.42 minutes), and anesthesiology personnel (MET 4.70 minutes). DISCUSSION: The use of SCAs (termed "Mega Code") serves as an extension of Basic Life Support and Advanced Cardiac Life Support education and provides a valuable learning experience and quality assurance tool. Limitations that might influence patient outcome during an actual in-hospital arrest have led to refinements in our cardiac arrest procedures. Of particular note was the delay in oxygen administration, which may be linked to its omission from the 1986 and 1992 American Heart Association Basic Life Support Guidelines. CONCLUSION: We believe that BLS education for hospital employees should include and emphasize oxygen delivery for resuscitation.

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 non-neonatal 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 end-expiratory 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 life-threatening 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 < 0.05). Comparisons of arterial blood gas and mechanical ventilation-related variables measured 24 hours before and again immediately before bypass were similar in the two cohorts with the exception of higher mean partial pressure of carbon dioxide (arterial) 24 hours before bypass in the recent treatment group. For our entire experience, younger age groups had greater survival rates; 100% of infants less than 1 year of age survived. 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.

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

OBJECTIVE: Recent 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. DESIGN: Retrospective, case-series chart review. SETTING: A university tertiary medical center. PATIENTS: Infants 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. INTERVENTIONS: Veno-venous or veno-arterial extracorporeal life support. MEASUREMENTS AND MAIN RESULTS: From 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. CONCLUSIONS: Based 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.

Influence of tidal volume, respiratory rate, and supplemental oxygen flow on delivered oxygen fraction using a mouth to mask ventilation device.

We examined the influence of the following parameters in determining the FiO2 delivered to a pediatric lung model using the mouth-to-mask method of resuscitation: rate of ventilation, inspiratory tidal volumes, and supplemental oxygen flow. With a ventilator rate of 20/min and tidal volumes (Vt) < or = 100 mL, an FiO2 of approximately .50 was observed with a supplemental oxygen flow of 5 L/min. Increasing the supplemental oxygen flow to 15 L/m did not appreciably increase the FiO2 (FiO2 = .53 versus FiO2 = .60, respectively), but did cause a significant and unintended increase in Vt. Similar results were noted with a ventilator rate of 12/min and Vt < or = 100 mL (FiO2 = .68 versus FiO2 = .73, respectively). We also observed a potentially hazardous situation involving the positioning of the supplemental oxygen port that might result in high inspiratory pressures (stacking of breaths) to the pediatric patient. We believe additional testing is warranted prior to widespread use of this device in children.

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

OBJECTIVE: 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 failures. 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. Stepwise 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.

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.

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

OBJECTIVE: To determine recent morbidity and mortality rates from respiratory syncytial virus infection in a pediatric congenital heart disease population. DESIGN: Retrospective cohort study design. SETTING: The C. S. Mott Children's Hospital, University of Michigan Medical Center. PATIENTS: A 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. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We retrospectively examined the charts of 740 patients hospitalized at our children's 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). CONCLUSIONS: We 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.

Use of extracorporeal life support in patients with congenital heart disease.

OBJECTIVES: To review a large experience with extracorporeal life support in patients with congenital heart disease. To determine the major causes of mortality and morbidity in order to improve the results of using this technology in this patient population. DESIGN: Retrospective chart review. PATIENTS: Twenty-five patients between the ages of 1 day and 8 yrs. These patients had congenital heart disease and were clinically felt to be at high risk for death caused by cardiac failure or by respiratory failure complicated by congenital heart disease. INTERVENTIONS: All patients in this report were placed on extracorporeal life support to allow recovery of myocardial or pulmonary function. MEASUREMENTS AND MAIN RESULTS: Of these 25 patients, 52% were weaned from bypass support and 40% survived to discharge. Patients who were not weaned from extracorporeal life support characteristically suffered from irreversible neurologic injury, multiple organ failure, or bleeding complications. Only one patient died of irreversible cardiac failure. CONCLUSIONS: Extracorporeal life support can be useful in supporting patients with congenital heart disease with life-threatening cardiac or pulmonary failure. Improvements in limiting neurologic and bleeding complications may lead to improvements in the use of extracorporeal life support for this indication. However, prospective, randomized studies are needed to appreciate the role of extracorporeal life support in these patients.