Pertinence of the CPSP to emergency medicine specialists

The emergency room:

An emergency room physician is on duty on a hectic day at a children’s hospital, and his first two patients include a three-year-old boy with hives, swollen lips, a hoarse voice and dyspnea after peanut ingestion, and a 10-year-old girl with dehydration, Kussmaul’s breathing and lethargy. The physician correctly diagnoses the boy with anaphylaxis (ANAP), and diagnoses the girl with diabetic ketoacidosis (DKA) and questions the possibility of cerebral edema (CE). Both children have serious life-threatening medical conditions that require urgent, carefully selected interventions. In each case, the potential for death or devastating permanent neurological sequelae exists. What can be gained by including the two conditions in the Canadian Paediatric Surveillance Program (CPSP)?

Anaphylaxis:

Small retrospective studies suggest that the incidence of ANAP is increasing in North America; at the same time, however, there is concern that ANAP is underdiagnosed in children. One problem that compounds a clear understanding of the epidemiology of ANAP is the lack of a standard definition. Some physicians restrict the diagnosis of ANAP to conditions that are life-threatening, while others use the term ‘anaphylaxis’ to include all severe acute allergic reactions. One advantage of the CPSP study on ANAP is that it provides all participants with a standard case definition. To date, there have been 491 reports of anaphylaxis of all 833 CPSP reports. This number seems to indicate that participants are adhering to the broader case definition and are reporting all severe, acute systemic allergic reactions, not just those that are life-threatening. Educational resources will be needed for health professionals, as well as for educators, patients and families, to encourage the use of the broader case definition.

Cerebral edema in diabetic ketoacidosis:

It is not clear whether CE in children with DKA is an integral part of the disease process (idiosyncratic) or a complication of fluid or other management (iatrogenic). A recent 15-year retrospective review (1) of 61 matched cases in the United States suggested that the risk of CE in DKA (CE-DKA) was associated with factors that were present both at presentation (increased initial serum urea nitrogen and decreased initial partial pressure of carbon dioxide) and during treatment (bicarbonate administration and failure of the serum sodium to rise during treatment). The CE-DKA CPSP study, which commenced in July 1999, has generated 40 reports in the first 18 months (15 cases are confirmed; eight cases are under review). Three children died, resulting in a significant mortality rate of 20% in the confirmed cases. Five cases have involved children presenting with CE before treatment was initiated. Preliminary results do not show a decreased partial pressure of carbon dioxide to the degree reported in the recent retrospective analysis, but a case control study is pending. The dissemination of the CE-DKA case definition, the protocol and an educational resource article has increased participant awareness, resulting in more timely and uniformly comparable data.

Results from the CE-DKA CPSP study will add to the body of evidence to consider whether the cause of CE in children with DKA is idiosyncratic rather than iatrogenic. The three deaths show that DKA is a serious condition; every child who presents with DKA should be monitored closely for signs of CE. Management guidelines for DKA, which are currently being drafted by the Ontario Ministry of Health, recommend not giving bicarbonate if a child’s pH is above 7. Further, a continuous intravenous infusion of insulin should be administered, and not a bolus of insulin.

Conclusion:

The CPSP is highly pertinent to all paediatric health care providers, including emergency medicine specialists.

Figure 1).

Portion of the Canadian Paediatric Surveillance Program’s reporting card