Cardiac rhabdomyoma with cardiac arrest

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A prospective study of femoral catheter-related thrombosis in children

OBJECTIVES

To establish the incidence and correlate clinical findings of femoral venous catheter-related thrombus formation in critically ill children.

RESEARCH DESIGN

Observational prospective blinded study.

SETTING

University-affiliated pediatric hospital intensive care unit.

PATIENTS

Twenty children admitted to the pediatric intensive care unit who had percutaneous femoral venous catheters placed while in the pediatric intensive care unit.

INTERVENTIONS

None.

MEASUREMENTS

Duplex Doppler ultrasonography evaluation of femoral vein catheters at 1 to 2, 3 to 5, and 7 to 10 days after placement was used to detect the presence of thrombus formation and venous occlusion. Demographic patient data, pediatric risk of mortality scores, and clinical findings, including leg swelling and whether catheters would aspirate blood, were also recorded. Continuous data were analyzed using the Mann-Whitney U Test, and categorical data were compared with Fisher's Exact Test. Statistical significance was assigned at a P value of .05 or less.

CONCLUSIONS

The overall incidence of catheter-related femoral vein thrombus formation was 35% (7/20). Ipsilateral leg swelling and the inability to aspirate blood from the catheter were significantly associated with thrombus formation. Patients who developed thrombi were younger and smaller than those who did not. In six of seven patients, thrombus formation was clinically occult when first demonstrated by ultrasonography.

Repair of a laryngotracheoesophageal cleft in an infant by means of extracorporeal membrane oxygenation

Few survivors have been reported following attempted repair of laryngotracheoesophageal clefts (LTECs). The major challenge is maintaining oxygenation, both during the surgical repair and during the postoperative period of healing. We report a neonate with an LTEC extending to the carina whose successful repair was facilitated by extracorporeal membrane oxygenation (ECMO) begun intraoperatively and continued postoperatively for 11 days. The intraoperative surgical exposure of the defect was excellent. Postoperative trauma to the fresh tracheal repair from ventilatory pressures and endotracheal tube motion was eliminated through the use of ECMO. The patient was discharged without a tracheotomy and with a normal voice, cry, and swallow. According to this result, the use of ECMO may represent a significant advance in facilitating the correction of major laryngotracheoesophageal anomalies. The rationale, advantages, disadvantages, and potential pitfalls of this approach are presented, as well as preoperative and postoperative documentation of our results.

Spontaneous pneumomediastinum

A case of spontaneous pneumomediastinum with cervical emphysema is reported. Spontaneous pneumomediastinum may complicate processes that decrease pulmonary interstitial pressure or increase intraalveolar pressure leading to alveolar rupture. Free air may then tract along blood vessels and decompress into the soft tissues of the neck. Clinical symptoms include neck and chest pain, dysphonia, and shortness of breath. Care is supportive unless the patient has a history of trauma or foreign body aspiration. Symptoms typically resolve within days.

Drowning and immersion injuries in children

Drowning and immersion injuries are leading causes of mortality and morbidity in children. An increasing amount of epidemiologic information is available. New modalities for managing respiratory failure, such as extracorporeal membrane oxygenation, are being explored. The realization that aggressive neurointensive care does not improve desirable outcome after near-drowning has led to investigations on preventing secondary brain injury that focus on monitoring and restoring cerebral oxygenation and circulation, reversing hypothermia, and maintaining normal blood glucose levels. Efforts at early neurologic prognostication and identification of victims who are likely to die or persist in a vegetative state are increasingly accurate and are highly relevant. Critical care physicians are more likely to withhold or withdraw support from victims who have minimal likelihood of meaningful recovery.

Extracorporeal membrane oxygenation: support for overwhelming pulmonary failure in the pediatric population. Collective experience from the extracorporeal life support organization

Data from the Extracorporeal Life Support Organization (ELSO) regarding the use of extracorporeal membrane oxygenation (ECMO) in pediatric patients with respiratory failure are reviewed. Two hundred eighty-five children between the ages of 14 days and 18 years were supported with ECMO between January 1982 and September 1991. Although these data represent the experience of 52 ECMO centers, seven centers accounted for over 50% of the total. The patients had a mean age of 33 +/- 48 months with a median age of 13 months: 137 (48%) were male and 148 (52%) were female. There were numerous primary pulmonary diagnoses: the two most common were presumed viral pneumonia (32%) and adult respiratory distress syndrome (28%). Entry criteria for ECMO, although poorly defined and specific to each institution, attempted to identify children with an 85% to 100% predicted mortality. The survival rate with ECMO was 47% (135/285). Pre-ECMO mechanical ventilatory support was extreme with an FIO2 .97 +/- .07 and a mean airway pressure (MAP) 23.6 +/- 8 cm H2O used to achieve PaO2 of 50 +/- 39 and PaCO2 51 +/- 22 mm Hg. The MAP was significantly higher in nonsurvivors versus survivors (25.3 +/- 8.7 v 22.0 +/- 7.1 cm H2O, P < .01). The duration of ECMO was 4 hours to 35.5 days with a mean of 245 +/- 165 hours, which is approximately 10 days. Duration for survivors was 222 +/- 151 hours compared with 266 +/- 176 hours for nonsurvivors. ECMO complications are divided into two categories: mechanical (directly related to the ECMO circuit) and medical (patient related).(ABSTRACT TRUNCATED AT 250 WORDS)

Extracorporeal membrane oxygenation

Extracorporeal membrane oxygenation is still a relatively new technology that has recently achieved recognition after initial clinical disappointment in the late 1970s. At present, it is considered standard therapy for the full-term infant with PPHN who fails CMV and extraordinary, heroic therapy for older children and adults with ARF or cardiac failure, or both. Currently, the emphasis is on developing new technologies for increasing safety and effectiveness. Areas of interest include heparinless circuits, carotid artery reconstruction, improved monitoring, and expanding applications of VV ECMO. As ECMO becomes safer and more effective, it is believed that new and expanding patient populations will emerge to include premature infants, earlier intervention in term infants, and more liberal application to pediatric and adult populations.

Delayed repair and preoperative ECMO does not improve survival in high-risk congenital diaphragmatic hernia

It has been suggested that delayed repair with preoperative stabilization might improve survival in high-risk (symptomatic within 6 hours of birth) congenital diaphragmatic hernia (CDH). This study compares the results of immediate operation versus delayed repair using extracorporeal membrane oxygenation (ECMO) when necessary. Since we first used ECMO in 1984, 101 high-risk CDH infants have been treated. Prior to 1987, we used immediate repair and postoperative ECMO if necessary. Between 1987 and 1990 we combined delayed operation (24 to 36 hours) with preoperative ECMO as necessary. No infant in this series was excluded from ECMO therapy unless absolute contraindications existed (prematurity, intracranial hemorrhage, or other major anomalies). Fifty-five patients received immediate operation and 46 had delayed repair. The two groups were comparable populations based on gestational age, birth weight, age at onset of symptoms, Apgar scores, best postductal PO2 (BPDPO2), and frequency of antenatal diagnosis. There was no statistically significant difference in overall survival between the two groups. Differences in survival among subpopulations (BPDPO2 greater than 100 or less than 100, antenatal diagnosis, inborn v outborn) also are not significant. The requirement for ECMO was similar in both groups. Survivors in the delayed repair group were ventilated longer and on ECMO longer, but had fewer late deaths (greater than 21 days) and fewer pulmonary sequelae (O2 dependency at discharge) than infants in the immediate repair group (P less than .05).(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiotoxicity during treatment of severe childhood asthma

We prospectively evaluated 20 patient admissions for severe exacerbation of childhood asthma at The Children's Hospital, Boston, to detect evidence of cardiotoxicity. Evidence of cardiotoxicity was found in all six patient admissions for which isoproterenol infusion was utilized. This included marked elevation of serum creatine phosphokinase isoenzyme (CPK-MB) levels and electrocardiogram abnormalities consistent with transient myocardial ischemia. Peak serum CPK-MB levels were significantly lower and electrocardiogram abnormalities were significantly less frequent during 14 patient admissions for which isoproterenol infusion was not utilized. Risk factors associated with cardiotoxicity included tachycardia, hypercapnia, acidosis, and intravenous isoproterenol therapy. We conclude that cardiotoxicity is not infrequent during therapy for severe exacerbations of childhood asthma. Electrocardiograms and measurement of serum CPK-MB levels are sensitive, useful, and readily obtained indicators of cardiotoxicity. Abnormalities of these studies may detect cardiotoxicity prior to the occurrence of more blatant or catastrophic manifestations of cardiotoxicity. We therefore recommend serial monitoring of serum CPK-MB levels and electrocardiograms for all children requiring an admission to the intensive care unit for management of severe asthmatic exacerbation.

Extracorporeal life support for cardiac assist in pediatric patients. Review of ELSO Registry data

The collected data on extracorporeal membrane oxygenation (ECMO), now referred to as extracorporeal life support (ECLS), for pediatric cardiac support has not been analyzed. The purpose of this study was to review the Extracorporeal Life Support (ELSO) Registry data to evaluate the results, identify possible predictors of outcome, and attempt to establish criteria. From 1981 to June of 1990, 189 patients were placed on ECLS for cardiac assist. The age range was 0-204 months (median, 7 months). Mean time on ECLS was 115 +/- 75 hours. Fourteen patients were placed on ECLS as a bridge to transplant or for management of transplant rejection. All of the remaining 175 patients were treated in the postoperative period. The causes of mortality included lack of improvement in cardiovascular function in 69 (37%) of the patients, major central nervous system damage in 28 (15%), uncontrollable hemorrhage in three (2%), sepsis in three (2%), and pulmonary interstitial disease in two (1%). The Registry data were examined for predictors of outcome. There was no significant difference between survivors and nonsurvivors when compared for duration of ECLS, mechanical complications, arterial or venous blood gases, ventilation settings, or hemodynamics. Forty-three percent of 189 pediatric patients treated with ECLS for cardiac failure survived. The highest survival, 61%, occurred in right-sided lesions and the lowest, 18%, in post-Fontan. Mediastinal bleeding, cardiac arrest, renal failure, and prolonged intubation were all associated with a poor outcome. Most deaths were attributed to irreversible cardiac or brain injury, suggesting that results could be improved by earlier identification of high-risk patients and earlier institution of ECLS.

The effect of extracorporeal membrane oxygenation on the survival of neonates with high-risk congenital diaphragmatic hernia: 45 cases from a single institution

At The Children's Hospital, Boston (TCH), in the 3 years before extracorporeal membrane oxygenation (ECMO) was available, infants with high-risk congenital diaphragmatic hernia (CDH) had a 47% survival rate. In February 1984, ECMO was introduced and offered to all high-risk CDH infants with a 100% predicted mortality. Since February 1984, 45 infants with high-risk CDH presented to TCH. Twenty-six (58%) were supported with ECMO; 19 (42%) never met the criteria for 100% predicted mortality and were supported with conventional mechanical ventilation (CMV). Overall survival was 49%. Nine (35%) of the 26 ECMO patients survived. Thirteen (68%) of the 19 CMV patients survived. Although there was no change in survival, there was a change in the cause of death. Deaths in the ECMO group were either early (n = 8, secondary to a complication of ECMO or lack of pulmonary improvement) or late (n = 9). The late deaths were infants who were successfully weaned from ECMO, never weaned from CMV, and who died secondary to complications of chronic lung disease.

Complications of mechanical ventilation in a children's hospital multidisciplinary intensive care unit

During a 12-week period, 204 consecutive patients admitted to the multidisciplinary intensive-care unit of a children's hospital were prospectively studied for complications of mechanical ventilation.

METHOD

A respiratory therapist completed a standardized data form at the end of each shift for each ventilated patient. Patient age, sex, length of ventilation, diagnosis, and complications were noted. Complications were classified as relating to the endotracheal tube (ETT), the ventilator, or the patient's medical management, and were analyzed according to incidence (number per 100 patients or per 100 ventilator days) and to associated mortality.

RESULTS

Patients ranged in age from newborn to 24 years. Sixty-three percent were male. Twenty-one percent of patients were managed by the medical staff, 11% by the general surgical staff, and 68% by the cardiac surgical staff. Average length of ventilation was 5.2 days. Overall survival rate was 91.7%. ETT complications reported as number per 100 patients were: pre-necrosis (13.0 [4/57 orally intubated patients and 23/147 nasally intubated patients]), ETT retaping complications (6.0), ETT plugging (1.0), and self-extubation (3.0). Ventilator complications reported as number per 100 ventilator days were: alarm failures (6.5), ventilator failures (0.7), and circuit problems (7.0). Medical complications reported as number per 100 patients were: massive gastric distension (8.8), right-upper-lobe collapse (4.4), pneumothorax (4.4), subcutaneous air (1.5), and pneumoperitoneum (1.0). ETT and ventilator complications showed no association with mortality. The large number of cardiac infants less than 24 months of age (n = 101) led us to further analyze this group for survival rate. We found that the survival rate was 93% for those requiring less than 7 days mechanical ventilation and 89.3% for those requiring greater than or equal to 7 days. As the study progressed, the respiratory therapists independently noted that their attentiveness to both patient and machine increased as did their awareness of complications. The incidence of alarm failure, circuit problems, and pre-necrosis was higher among the first 103 patients compared to the 101 patients entered into the study subsequently.

Oxygen extraction in lamb skeletal muscle

Past studies have found that total-body O2 extraction during hypoxia was less in 1-wk-old lambs than in older animals. It was proposed that reduced O2 extraction was secondary to suppression of growth-related oxygen consumption (VO2) in tissues such as skeletal muscle, bone, kidney, and skin, rather than a defect in peripheral O2 use. To determine the capacity of immature skeletal muscle to extract O2, we isolated the hind limb circulation of eight ketamine-anesthetized, 7- to 18-d-old lambs exposed to stagnant hypoxia by inflation of a right atrial balloon catheter. Femoral arterial and venous PO2, PCO2, pH, Hb concentration, O2 saturation, and femoral arterial blood flow (Q) were measured and hind limb O2 delivery (DO2), extraction ratio, and VO2 calculated. Individual critical levels of DO2 below which VO2 was dependent on O2 supply were determined by dual-line best-fit regression analysis. In six of eight animals, VO2 was clearly independent of supply until DO2 reached critically low levels. However, O2 extraction during extreme hypoxia appeared submaximal (baseline O2 extraction ratio, 0.22 +/- 0.06; at critical levels of DO2, 0.51 +/- 0.11; at the lowest level of Q, 0.64 +/- 0.15). When 2,4-dinitrophenol, an uncoupler of oxidative phosphorylation, was administered to four additional lambs exposed to stagnant hypoxia, O2 extraction below critical levels of DO2 increased from 0.48 +/- 0.15 to 0.79 +/- 0.10 (p less than 0.001, unpaired t test). These data suggest that initial limitations in O2 extraction were a result of the suspension of O2-consuming processes, not an irreversible defect in peripheral O2 use.

Extracorporeal Membrane Oxygenation and Conventional Medical Therapy in Neonates With Persistent Pulmonary Hypertension of the Newborn: A Prospective Randomized Study

Thirty-nine newborn infants with severe persistent pulmonary hypertension and respiratory failure who met criteria for 85% likelihood of dying were enrolled in a randomized trial in which extracorporeal membrane oxygenation (ECMO) therapy was compared with conventional medical therapy (CMT). In phase I, 4 of 10 babies in the CMT group died and 9 of 9 babies in the ECMO group survived. Randomization was halted after the fourth CMT death, as planned before initiating the study, and the next 20 babies were treated with ECMO (phase II). Of the 20, 19 survived. All three treatment groups (CMT and ECMO in phase I and ECMO, phase II) were comparable in severity of illness and mechanical ventilator support. The overall survival of ECMO-treated infants was 97% (28 of 29) compared with 60% (6 of 10) in the CMT group (P&lt; .05).

Role of extracorporeal membrane oxygenation in selected pediatric respiratory problems

Between 1984 and 1988, 89 infants and children with severe respiratory failure were supported by extracorporeal membrane oxygenation. Major clinical diagnoses included congenital diaphragmatic hernias (34), meconium aspiration syndrome (26), and sepsis (8). Extracorporeal membrane oxygenation was used for patients with a predicted mortality rate of at least 80% based on an oxygenation index greater than 0.4. Venoarterial bypass was accomplished by way of right cervical cannulation of the common carotid artery and internal jugular vein. Overall survival was 71% but varied widely by diagnosis and progressively improved over time. The average extracorporeal membrane oxygenation run was 5.7 days. Intracranial hemorrhage was the most serious complication occurring in 16% of patients. Mechanical circuit complications were seen in 22% but rarely related to significant morbidity. Extracorporeal membrane oxygenation appears to provide effective cardiopulmonary support for selected pediatric respiratory problems. It affords those with potentially reversible pathophysiology the temporal opportunity for successful medical or surgical therapies.

Fetal diaphragmatic hernia: ultrasound diagnosis and clinical outcome in 38 cases

A previously published survey has evaluated the natural history and clinical outcome of fetal diaphragmatic hernia (CDH) in 94 cases. This study showed that the prenatal diagnosis is accurate, the mortality is high (80%), and polyhydramnios is a prenatal predictor of poor clinical outcome. As a follow-up study, 38 consecutive cases of CDH diagnosed in utero were evaluated and treated by the same surgical team. This permitted detailed assessment of prognostic factors and evaluation of the impact of extracorporeal membrane oxygenation (ECMO) on outcome. We found the following. (1) Survival is poor despite optimal postnatal therapy including ECMO. (2) Polyhydramnios is both a common prenatal marker for CDH (present in 69% of fetuses) and a predictor for poor clinical outcome (only 18% survival), but tends to occur after the second trimester. (3) Amniocentesis is indicated to rule out chromosomal abnormalities that were present in 16% of fetuses. (4) All 14 fetuses diagnosed prior to 25 weeks' gestation died. Improved postnatal therapy or surgical intervention before birth will be necessary to salvage the CDH fetus with an early gestational diagnosis or associated polyhydramnios.

Neurological complications of hemolytic-uremic syndrome

Of 78 children identified with hemolytic-uremic syndrome at the Children's Hospital, Boston, from 1976 to 1986, 16 patients (20.5%) had neurological manifestations during their hospitalization. The most common manifestations were significant alterations in consciousness (coma, stupor) in 12 patients, and either generalized or partial seizures in ten patients. Others included hemiplegia (4 patients), decerebrate posturing (3), cortical blindness (2), hallucinations (1), and dystonic posturing (1). Cranial computed tomographic scans were abnormal in eight of 11 patients scanned. The abnormalities included diffuse cerebral edema (4 patients), large vessel infarctions (3), diffuse multiple small infarcts (4), and multiple hemorrhages (1). Five patients died as a result of their central nervous system complications, and six had neurological sequelae at discharge. Five patients recovered and at discharge had no evidence of neurological dysfunction.

Use of the postductal PaO2 as a predictor of pulmonary vascular hypoplasia in infants with congenital diaphragmatic hernia

Infants with congenital diaphragmatic hernia (CDH) demonstrate a wide range of anatomic and physiologic abnormalities that result in decreased pulmonary perfusion. We have used the patients' ability to achieve at least one postductal PaO2 greater than 100 torr while on maximal ventilation with 100% oxygen during the first 24 hours of life as the clinical marker to identify the degree of pulmonary perfusion. Patients were grouped as follows: group 1 had at least one postductal PaO2 greater than 100 torr, and group 2 patients never had a postductal PaO2 above 100 torr. To see if this classification did reflect pulmonary vascular abnormalities, we compared the pulmonary arteriograms of these two groups of CDH infants for size of the main pulmonary arteries (PAs), size of the lungs, and degree of peripheral vascular obstructive disease (PVO). Infants in group 2 had significantly smaller ipsilateral and contralateral main PAs, as well as smaller ipsilateral lungs with more severe PVO. We propose the postductal PaO2 as the clinical marker for identification of the degree of pulmonary perfusion.