Peter N. Cox

Desmopressin (1-deamino-8-D-arginine vasopressin, DDAVP) has been used in children with von Willebrand disease (VWD) and Hemophilia A for almost 35 years. This treatment has substantially lowered the number of children exposed to human plasma derived products, with a good safety profile, and at very low cost. The response to DDAVP has been shown to be associated with age, baseline factor level, and genetic mutations. A DDAVP challenge test is recommended. DDAVP has also been used to prevent and treat bleeding episodes in children with platelet function defects and other disorders associated with bleeding tendency.

BACKGROUND: Among adults who have a cardiac arrest outside the hospital, the survival rate is known to be poor. However, less information is available on out-of-hospital cardiac arrest among children. This study was performed to determine the survival rate among children after out-of-hospital cardiac arrest and to identify predictors of survival. METHODS: We reviewed the records of 101 children (median age, two years) with apnea or no palpable pulse (or both) who presented to the emergency department at the Hospital for Sick Children in Toronto. The characteristics of the patients and the outcomes of illness were analyzed. We assessed the functional outcome of the survivors using the Pediatric Cerebral and Overall Performance Category scores. RESULTS: Overall, there was a return of vital signs in 64 of the 101 patients; 15 survived to discharge from the hospital, and 13 were alive 12 months after discharge. Factors that predicted survival to hospital discharge included a short interval between the arrest and arrival at the hospital, a palpable pulse on presentation, a short duration of resuscitation in the emergency department, and the administration of fewer doses of epinephrine in the emergency department. No patients who required more than two doses of epinephrine or resuscitation for longer than 20 minutes in the emergency department survived to hospital discharge. The survivors who were neurologically normal after arrest had had a respiratory arrest only and were resuscitated within five minutes after arrival in the emergency department. Of the 80 patients who had had a cardiac arrest, only 6 survived to hospital discharge, and all had neurologic sequelae. CONCLUSIONS: These results suggest that out-of-hospital cardiac arrest among children has a very poor prognosis, especially when efforts at resuscitation continue for longer than 20 minutes and require more than two doses of epinephrine.

OBJECTIVES: To test the hypotheses that during small tidal volume ventilation (5 mL/kg) deliberate volume recruitment maneuvers allow expansion of atelectatic lung units and that a high positive end-expiratory pressure (PEEP) above the lower inflection point of the pressure/volume (PV) curve is not necessarily required to maintain recruited lung volume in acute lung injury. DESIGN: Prospective, randomized, controlled animal study. SETTING: An animal laboratory in a university setting. SUBJECTS: Adult New-Zealand rabbits. INTERVENTIONS: We studied a) the relationship of dynamic loops during intermittent positive pressure ventilation to the quasi-static PV curve, and b) the effect of lung recruitment on oxygenation, end-expiratory lung volume (EELV), and dynamic compliance in two groups (n = 4 per group) of lung-injured animals (lung lavage model): 1) the sustained inflation group, which received ventilation after a recruitment maneuver (sustained inflation); and 2) the control group, which received ventilation without any lung recruitment. MEASUREMENTS AND MAIN RESULTS: In the presence of PV hysteresis, a single sustained inflation to 30 cm H2O boosted the ventilatory cycle onto the deflation limb of the PV curve. This resulted in a significant increase in EELV, oxygenation, and dynamic compliance despite equal PEEP levels used before and after the recruitment maneuver. Furthermore, after a single sustained inflation, oxygenation remained high over 4 hrs of ventilation when a PEEP above the critical closing pressure of the lungs, defined as "optimal" PEEP, was used and was significantly higher compared with that in the control group ventilated at equal PEEP without preceding lung recruitment. CONCLUSIONS: The observation that ventilation occurs on the deflation limb of the tidal cycle-specific PV curve allows placement of the ventilatory cycle, by means of a recruitment maneuver, onto the deflation limb of the PV envelope of the optimally recruited lung. This strategy ensures sufficient lung volume recruitment to maintain the lungs during the tidal cycle while using relatively low airway pressures.