C. Anthony Ryan

No resuscitation and withdrawal of therapy in a neonatal and a pediatric intensive care unit in Canada

Study objective: To compare and contrast the modes of death in a neonatal(NICU) and a pediatric (PICU) intensive care unit. Design: Retrospective analysis of patient records. Subjects: All newborn infants and children ( Results: The mortality rate in the PICU was 8.7% (73/839) compared with 5.6% (75/1333) in the NICU (p=0.007). Withdrawal of therapy was the most common cause of death in both units and occurred more commonly in the NICU (NICU=69% vs PICU=34%; p=0.01). There were significantly more deaths as a result of failed cardiopulmonary resuscitation (CPR) in the PICU than in the NICU (29% vs 13%; p=0.046). Death after no-CPR orders occurred with equal frequency in both units (NICU 17%; PICU 15%). Brain death accounted for 22% (16/87) of PICU deaths; no infant in the NICU was declared brain dead (p Conclusions: This study confirms that both withdrawal of therapy and no-CPR orders are part of current clinical practice in both the NICU and PICU settings. The ethical foundations and implications of these practices need further elaboration.

Extracorporeal membrane oxygenation in infants with congenital diaphragmatic hernia and cardiac malformations

Since the introduction of neonatal extracorporeal membrane oxygenation (ECMO) in Canada, the authors have treated three infants with congenital diaphragmatic hernia (CDH) who had serious congenital cardiac anomalies (among 26 infants with CDH treated with ECMO). To determine the incidence of and outcome for infants with combined lesions who received ECMO, 19 years data (April 1973 to October 1992) from the Extracorporeal Life Support Organization (ELSO) registry were reviewed. Seventeen infants with combined cardiac and diaphragmatic lesions were registered as receiving ECMO in the United States or Canada. Thus, the incidence of combined cardiac and diaphragmatic lesions was 2.5 per thousand neonates (17 of 6,295) receiving ECMO and 13 per thousand neonates (17 of 1,318) receiving ECMO for CDH. Five (29.4%) of the 17 infants survived. A congenital cardiac lesion may not be an absolute contraindication to ECMO in infants with CDH. Decisions to cannulate for ECMO should be based on the potential outcome of the underlying cardiac defect.

Seizures due to lidocaine toxicity in a child during cardiac catheterization.

SummaryA 17-month-old boy developed grand mal seizures secondary to lidocaine toxicity during balloon dilatation of a congenital pulmonary valve stenosis. Lidocaine at 38 mg/kg (nine times the recommended maximum dose of 4.5 mg/kg) was administered during a 90-min period in order to optimize local anesthesia. This resulted in toxic serum lidocaine levels (8.7 mg/L; therapeutic range, 1.5–5 mg/L) at the time of seizures. Caution should be exercised with local anesthetics during invasive cardiac catheterizations. Hypercarbia (which lowers the seizure threshold to local anesthetics) should be avoided and the temptation to exceed the maximum recommended dose resisted.

Congenital diaphragmatic hernia: Associated malformations-cystic adenomatoid malformation, extralobular sequestration, and laryngotracheoesophageal cleft: Two case reports

Two infants with unusual bronchopulmonary malformations associated with congenital diaphragmatic hernia (CDH) are presented. One infant had extralobular sequestration and cystic adenomatoid malformation of the lower lobe, in addition to a left-sided CDH. The second infant had a laryngotracheoesophageal cleft extending to the carina (type III) in addition to a left-sided CDH. These associated malformations can have major implications in terms of diagnosis, resuscitation, and surgical management of infants with CDH.

Directly measured arterial oxygen saturation in the newborn infant

An understanding of oxygen transport is fundamental to the management of the critically ill neonate, because at no other time in life is the oxyhemoglobin dissociation curve in such a state of flux? Current practice relies almost exclusively on oxygen tension as an index of oxygenation, but oxygen content and saturation and the affinity of hemoglobin for oxygen are also important in tissue oxygen delivery. We directly measure arterial oxygen hemoglobin saturation with a co-oximeter and calculate P503 (the Po2 at which the blood is 50% saturated) as a guide in the management of oxygen therapy. With this information we establish daily limits for the transcutaneous Po2 monitors in order to maintain HbO2% between 80% and 90%. We were impressed with the high carboxyhemoglobin levels recorded by the co-oximeter, but found that this is a feature of the instrument in the presence of fetal hemoglobin. +,5 This study was undertaken to test the hypothesis that the measured HbCO% is related to the HbF%; we postulated that it could provide an indirect but simple method of determining HbF concentration.

Home Nebulizers in Childhood Asthma Parental Perceptions and Practices

Seventy five percent of 91 parents of asthmatic children (aged 6 months to 15.4 years) with home nebulizers, responded to a questionnaire that sought to document parental experience with this form of therapy. The most common indications for acquiring a nebulizer were inability to use metered dose inhalers and poor response or intolerance to oral medications. When the children were classified into those who used the nebulizer daily (27/69) and those who used it less than daily (42/69), we found that the daily users were more likely to be in the severest category of asthma, by parental assessment, prior to the home nebulization program (p = 0.0035). Retrospective, uncontrolled comparison before and after the acquisition of a home nebulizer showed significant decreases both in hospital admissions (1.7 vs 0.7; p < 0.001) and total in-patient days (4.1 vs 1.7; p < 0.0001). Home nebulizers are well tolerated by parents and children alike and may be associated with decreased morbidity.

Unusual Cause of Methadone Poisoning

ABSTRACT. A child with respiratory distress was found to have been given an antibiotic which was reconstituted with methadone. A delay in standard emergency room management led to a delay in diagnosis and treatment.

Pulse oximetry during hemorrhagic hypotension and cardiopulmonary resuscitation in the rabbit

A new transcutaneous oxygen saturation monitor, the pulse oximeter, was evaluated during hemorrhagic hypotension and cardipuimonary resuscitation (CPR) in six anesthetized and paralyzed adult rabbits. A combined transcutaneous oxygen and carbon dioxide electrode was evaluated simultaneously. The animals were initally subjected to graded hemorrhage and reinfusion. The transcutaneous saturation correlated significantly with arterial oxygen saturation until severe hypotension ensued and pulsation could no longer be detected. TcPO2 began to fall and TcPCO2 values began to rise, compared with arterial values, as the blood pressure fell below 100 mm Hg. Asystole was then induced and CPR instituted. Probe movement during CPR produced a fallacious appearance of pulsation and a spurious estimate of saturation. TcPO2 was between 0 to 4 torr and the TcPCO2 was in excess of 150 torr during CPR; neither correlated with arterial values. Pulse oximetry is a valuable method of continuously monitoring arterial oxygenation over a wide range of blood pressures, but it is adversely affected by probe movement. Further studies are required to determine the clinical limitations of this useful device.

Radiological decompression of bowel gas and return of mediastinal shift in congenital diaphragmatic hernia: A signal for surgical repair?☆

The objective of this study was to document the pattern of bowel gas decompression and mediastinal shift in infants with congenital diaphragmatic hernia (CDH) before delayed surgical correction. The setting was the Neonatal Intensive Care Unit, Royal Alexandra Hospital, Edmonton. The design was a retrospective review of radiographs and charts of all infants with CDH between January 1990 and December 1993. Bowel gas in the upper and middle one third of the hemithorax was classified as grade III and grade II, respectively. Bowel gas in the lower one third of the hemithorax or absent bowel gas was classified as grade I. All the infants showed partial return of the contralateral shift in the mediastinum toward the midline when comparing the admission chest radiographs with the immediate preoperative films. Complete return of the mediastinum to normal (using the first postoperative radiograph as the gold standard) occurred in all but 1 of the 10 infants on extracorporeal membrane oxygenation (ECMO) (90%) and 7 of 13 (54%) of conventionally treated infants (P = .12). At the time of the first radiograph, a similar proportion of non-ECMO and ECMO infants (61% versus 70%, respectively) had either grade II or III bowel gas patterns. By 72 hours none of the non-ECMO-treated infants (who were paralyzed with muscle relaxants) had bowel gas in the middle and upper one third of the hemithorax. In contrast, 66% of infants on ECMO still had a grade II bowel gas pattern at 72 hours (P < .05), with 4 infants showing an actual increase in bowel gas after discontinuation of muscle relaxation.(ABSTRACT TRUNCATED AT 250 WORDS)

Asymptomatic subclavian steal syndrome in children following cardiac surgery: A potential hazard with re-operation?

SummaryWe describe a case of fatal hypoxic—ischemic encephalopathy, leading to brain death following the modified Fontan procedure in a child with asymptomatic subclavian steal syndrome (SSS). This patients brain death was most likely multifactorial in view of his postoperative course. However, we believe that the presence of the SSS contributed to the abnormal cerebral circulation during surgery and postoperatively, leading to brain death. The presence of SSS in patients undergoing an open-heart procedure may be a risk factor cerebral ischemia or brain death.