Acute poisoning in a children's hospital: a 2-year experience.

In a 2-year retrospective review, 90 patients were treated in a children's hospital for acute overdoses. In 90%, the history was the most important indicator of poisoning. On physical examination, 64% of patients were found to have altered sensorium, and 69% of cases were confirmed with a routine qualitative toxicology screening test. Accidental overdoses were most frequently due to ingestion of petroleum distillates, digoxin, carbamazepine, and theophylline. Suicidal patients ingested alcohol, barbiturates, tricyclic antidepressants, benzodiazepines, and aspirin. The majority of children with accidental overdoses received medical attention within 2 hours, but suicidal patients presented significantly later. Appropriate treatment with gastric lavage or emesis was used for 85% of patients on an emergency basis prior to admission. The inpatient therapy is based on continued gastrointestinal decontamination, basic organ system support, and monitoring for toxic effects and complications of therapy. Specific antidotes were available for only 10% of patients. In this study, 50% of patients were able to be discharged to their homes after one day of hospitalization. Pediatric patients treated in the intensive care unit incur less morbidity than adults in a similar setting. Adolescents who attempt suicide and are treated in the intensive care unit are likely to take prescription drugs in a similar manner as their adult counterparts.

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 less than .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.

Effect of pentoxiphylline on oxygen transport during hypothermia.

At least two investigators have demonstrated a reduction in O2 extraction during induced hypothermia (Cain and Bradley, J. Appl. Physiol. 55: 1713-1717, 1983; Schumacker et al., J. Appl. Physiol. 63: 1246-1252, 1987). We hypothesized that administration of pentoxiphylline (PTX), a theobromine that lowers blood viscosity and has vasodilator effects, would increase O2 extraction during hypothermia. To test this hypothesis, we studied O2 transport in anesthetized, paralyzed, mechanically ventilated beagles exposed to hypoxic hypoxia during either 1) normothermia (38 degrees C), 2) hypothermia (30 degrees C), or 3) hypothermia + PTX (30 degrees C and PTX, 20 mg.kg-1.h-1). Measurements included arterial and mixed venous PO2, hemoglobin concentration and saturation, cardiac output, systemic vascular resistance (SVR), blood viscosity, and O2 consumption (VO2). Critical levels of O2 delivery (DO2, the product of arterial O2 content and cardiac output) were determined by a system of linear regression. Hypothermia significantly decreased base line cardiac output (-35%), DO2 (-37%), and VO2 (-45%), while increasing SVR and blood viscosity. Addition of PTX increased cardiac output (35%) and VO2 (14%), and returned SVR and blood viscosity to normothermic levels. Hypothermia alone failed to significantly reduce the critical level of DO2, but addition of PTX did [normothermia, 11.4 +/- 4.2 (SD) ml.kg-1.min-1; hypothermia, 9.3 +/- 3.6; hypothermia + PTX, 6.6 +/- 1.3; P less than 0.05, analysis of variance]. The O2 extraction ratio (VO2/DO2) at the critical level of DO2 was decreased during hypothermia alone (normothermia, 0.60 +/- 0.13; hypothermia, 0.42 +/- 0.16; hypothermia + PTX, 0.62 +/- 0.19; P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Acute circulatory failure in children.

Circulatory failure exists when tissue metabolic demand exceeds availability. The most common cause of inadequate perfusion in children is hypovolemia. If recognized and treated early, hypovolemic shock responds readily to volume expansion. For those patients who do not respond, intelligent recommendations for pharmacologic support of the circulation are based on evaluation of hemodynamic parameters which include indices of flow, pressure, and resistance.

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.

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.

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.

The pulmonary hemodynamic response to perioperative anesthesia in the treatment of high-risk infants with congenital diaphragmatic hernia.

The continuing high mortality in congenital diaphragmatic hernia led us to study the cardiopulmonary disturbances associated with this lesion. Since these infants infrequently have right-to-left shunting in the operating room, we adopted a treatment protocol of: continuing general anesthesia in the postoperative period using fentanyl and pancuronium; cardiac catheterization postoperatively, including placement of a pulmonary artery line and a pulmonary angiogram; rapid frequency ventilation; moderate fluid restriction; and avoidance of vasodilators until other means of management had clearly failed. Fourteen high-risk infants, presenting within 6 hours of birth, were studied and compared to 17 high-risk infants, who served as historical controls. As revealed by the physiologic data acquired in the catheterization laboratory, high-risk infants divided into "Responder" and "Nonresponder" groups. Seven of 10 "Responders" actually shunted left to right during the catheterization, demonstrating a low pulmonary vascular resistance. Seven of 10 subsequently demonstrated significant right-to-left shunting at the level of the ductus and the foramen ovale, indicating the hyperreactivity of the pulmonary vascular bed. All but one was managed successfully by ventilatory adjustments and deepening of the level of anesthesia. "Nonresponders" had a fixed right-to-left shunt unresponsive to any medical or ventilatory manipulation. All "Nonresponders" died. Pulmonary angiography suggested a smaller diameter of the affected pulmonary artery compared to the main pulmonary artery in the "Nonresponders." This implies true hypoplasia resulting in a vasculature too small to accept a full cardiac output. Survival in the treatment group "Responders" was eight of 10 (80%) v seven of 14 (50%) in the control group.(ABSTRACT TRUNCATED AT 250 WORDS)

Renal and hemodynamic effects of dopamine in infants following cardiac surgery.

The renal and hemodynamic effects of dopamine were measured during the immediate postoperative period in six infants following repair of congenital cardiac defects. Dopamine was infused at rates of 5, 10, and 15 micrograms/kg/min. Cardiac index (CI) increased significantly at a dopamine infusion rate of 15 micrograms/kg/min. The glomerular filtration rate (GFR) and urine output increased at dopamine infusion rates of 5 and 10 micrograms/kg/min and returned to baseline at 15 micrograms/kg/min. No significant changes occurred in right atrial pressure (RAP), left atrial pressure (LAP), systemic artery pressure, systemic vascular resistance (SVR), or pulmonary vascular resistance (PVR). Heart rate (HR) increased slightly at a dopamine infusion rate of 15 micrograms/kg/min. Pulmonary artery pressure (PAP) increased significantly in only one patient. These data demonstrate that infants require high doses of dopamine to produce the hemodynamic effects seen in adults and that these higher doses may be used without adverse renal effects.

The cardiovascular effects of isoproterenol in the preterm newborn lamb.

We studied the effects of an isoproterenol infusion on cardiac output and the distribution of blood flow in 5 preterm newborn lambs. Cardiac output and regional organ blood flow were measured by injecting radionuclide-labeled microspheres into the superior vena cava and left ventricle. We found that an average infusion of 0.5 microgram/kg X min of isoproterenol increased cardiac output 73% which correlated closely with an increase in stroke volume, but not with HR. The increase in systemic blood flow was distributed exclusively to the myocardium and skeletal muscle, bone, and skin. We conclude that isoproterenol increases cardiac output in preterm newborn lambs similarly to adults and that the stroke volume of the immature heart is more changeable than previously thought.

Nitrous oxide analgesia for refractory pain in the terminally ill.

Nitrous oxide analgesia was used in the management of the terminal hospitalization of four adolescents and one child with disseminated cancer. All patients had severe pain that was unresponsive to standard regimens of narcotics and various narcotic analgesia-stimulant combinations. In each case, the addition of nitrous oxide led to an obvious improvement in symptoms of pain, anxiety, and agitation, while simultaneously improving appetite, mood, and the capacity to communicate. There were no side effects except those related to the discomfort of wearing a mask. Acceptance of the procedure by patient, family, and staff was universal and enthusiastic. The procedure is safe, easily administered, and noninvasive. Nitrous oxide can be useful in managing terminal illness refractory to standard pain control measures.

Experience with a modified laryngoscope in sick infants.

critically ill infants receiving supplemental oxygen for their hypoxemia may become significantly compromised by hypoxemia and bradycardia when supplemental oxygenation is interrupted to carry out laryngoscopy and tracheal intubation. It would, therefore, be desirable to devise a means of maintaining supplemental oxygenation during the procedure. A modified laryngoscope blade achieved this objective simply and efficiently. A study was performed on 8 newborn infants with hyaline membrane disease(HMD) who required laryngoscopy and tracheal intubation for progressive hypoxemia. All infants were hypoxemic during the procedure of laryngoscopy, breathing room air (mean PaO2 43 torr). The procedure was repeated with the modified blade (mean PaO2 87 torr). No significant bradycardia was noted. The procedure of intubation was less stressful both to the patient and to the operator. It would seem appropriate to use the modified laryngoscope blade in all situations where hypoxemia threatens. It would seem to have a particular place in intubation of the difficult airway.

Management of respiratory failure in infants with acute viral bronchiolitis.

Fifteen infants with acute viral bronchiolitis required mechanical ventilation. Infants were all aged less than 12 weeks and all had evidence of atelectasis or pneumonia on chest x-ray films. Respiratory syncytial virus was identified by immunofluorescence in 14 of 15 patients. Intubation and mechanical ventilation were initiated to reduce the work of breathing rather than to treat hypoxemia alone. Additional therapy included continuous positive airway pressure or positive end-expiratory pressure, sedation, aminophylline, diuretics, fluid restriction, and early feeding.

Recovery from pancuronium blockade in the neonatal intensive care unit.

Neuromuscular blockade with pancuronium and its antagonism was evaluated in 33 critically ill infants. The evoked contraction of the adductor pollicis from indirect stimulation of the ulnar nerve was measured. The neuromuscular blockade recovered spontaneously from pancuronium in seven infants, 23 required one or more doses of atropine 0.02 ng kg-1 and neostigmine 0.06 mgkg-1. In three infants the blockade failed to reverse. Immature infants less than 32 weeks did not show any significant different in their requirement for pancuronium compared with mature infants. Age and birth weight of the infant, dose of pancuronium and duration of its administration did not affect the requirements for reversal. Train-of-four and tetanus; twitch ratios were lower (P less than 0.05) in infants less than 32 weeks of developmental age reflecting immaturity of neuromuscular transmission.

Inappropriate secretion of antidiuretic hormone in a postsurgical pediatric population.

Twenty-four pediatric patients undergoing corrective posterior spinal fusion surgery for idiopathic scoliosis were studied to determine the frequency with which the syndrome of inappropriate antidiuretic hormone secretion (SIADH) developed. We measured arterial blood gases, serum and urine electrolytes and osmolalities, CVP, and urine output during and after surgery. The 20 patients receiving hypotonic iv salt solution in the immediate postoperative period experienced a significant drop in serum sodium values (6.2 +/- 2.9 mEq/L) and 5 (25%) developed SIADH as diagnosed by routine laboratory procedures. Four patients were treated with iv isotonic salt solution. No patient developed hyponatremia (serum Na+ less than 130 mEq/L) and the decrease in serum sodium (3.0 +/- 0.8 mEq/L) was not statistically significant. We conclude that SIADH occurs commonly in patients undergoing corrective vertebral surgery and that vigilant attention must be paid to their fluid and electrolyte management in the postoperative period.

Effect of isoproterenol on measured theophylline levels.

Aggressive pharmacotherapy for the treatment of patients with severe status asthmaticus includes theophylline and beta-adrenergic agonists such as isoproterenol. We found that the measured theophylline level decreased when an isoproterenol infusion was started, and this decrease persisted throughout the entire exposure to isoproterenol. When the isoproterenol infusion was discontinued, the theophylline level increased. The etiology of this observed effect is unknown.