Treatment of persistent pulmonary hypertension of the newborn without hyperventilation: an assessment of diffusion of innovation.

OBJECTIVE: The treatment of neonates with persistent pulmonary hypertension of the newborn (PPHN) is controversial with no consensus on diagnostic criteria or treatments. Hyperventilation has been the therapeutic mainstay. However, two widely variant alternative approaches have been proposed: ventilation without induced alkalosis, or more aggressive therapies such as high frequency ventilation or extracorporeal membrane oxygenation. We wished to determine the extent to which these alternative treatments have diffused into practice. METHODS: A forced choice questionnaire was mailed to a sample representing 10% of 3740 practicing neonatologists. Sixty percent of those surveyed responded. Data on treatment practices was tabulated. Subanalyses with respect to training era, practice site, and geographic region were performed. RESULTS: In patients with meconium aspiration syndrome, without evidence of PPHN, 36% described their initial management as hyperventilation. If PPHN was confirmed, hyperventilation was used in 90% of patients by 44% of the respondents. Muscular paralysis and inotropic support were also used frequently. Alkali and vasodilator infusion were used less frequently. The gentle ventilation strategy proposed by Wung and James at Columbia Babies Hospital was used infrequently by 47% of respondents. Gentle ventilation was used more frequently by board-certified neonatologists than those not certified. No significant differences in practice were identified by geographic region or era of training. When standard treatment failed, only 40% of the respondents utilized rescue treatments such as high frequency ventilation or extracorporeal membrane oxygenation. CONCLUSIONS: This study documents that gentle ventilation, an easily and inexpensively adopted innovation, has not diffused into practice significantly while more expensive high technology treatments, such as high frequency ventilation and extracorporeal membrane oxygenation, have penetrated more significantly.

Impact of prolonged saline solution prime exposure on integrity of extracorporeal membrane oxygenation circuits.

OBJECTIVE: Our purpose was to evaluate the safety of the common practice of preparing extracorporeal membrane oxygenation (ECMO) circuits in advance with saline solution priming by analysis of the surfaces of circuit components and analysis of the prime solution for toxic contaminations. STUDY DESIGN: In vitro analysis of eight ECMO circuits exposed to saline prime solution for 0, 2, or 4 weeks was performed with scanning electron microscopy. Prime solution analyzed for contamination with aluminum, silicone, and diethylhexylphthalate. RESULTS: The silicone membrane and heat exchanger demonstrated surface degradation in contact with saline solution. The prime solution showed increasing concentrations of both aluminum and silicone but not diethylhexylphthalate over time. CONCLUSIONS: Advance preparation of ECMO circuits by prepriming with normal saline solution leads to significant circuit degradation. Prepriming should be avoided.

The natural history of direct hyperbilirubinemia associated with extracorporeal membrane oxygenation.

OBJECTIVE: To determine the incidence and natural history of direct hyperbilirubinemia in neonates treated with extracorporeal membrane oxygenation. DESIGN: A prospective series of patients. SETTING: A level 3 neonatal intensive care unit and center for extracorporeal membrane oxygenation in Ohio. PARTICIPANTS: Sixty-seven consecutive patients treated with extracorporeal membrane oxygenation in 33 months. INTERVENTION: None. MEASUREMENTS/RESULTS: Twenty-six (39%) developed direct hyperbilirubinemia. In 14 (54%), bilirubin levels were mildly elevated and occurred only during extracorporeal membrane oxygenation therapy. Levels were more severely elevated in the remaining 12 patients (46 +/- 10 mumol/L [2.7 +/- 0.6 mg/dL] vs 159 +/- 101 mumol/L [9.3 +/- 5.9 mg/dL], P less than .0001). Duration and severity of hyperbilirubinemia were correlated. Hyperbilirubinemia resolved in all patients by 9 weeks after extracorporeal membrane oxygenation therapy. No structural abnormalities or infectious agents were identified as causes. Aluminum levels were evaluated for 40 patients, were not in the toxic range, and did not correlate with hyperbilirubinemia. Multiple linear regression analysis suggested that hyperbilirubinemia in these cases resulted from interaction of injuries, with the primary contributor being hemolysis during extracorporeal membrane oxygenation. CONCLUSIONS: Direct hyperbilirubinemia occurs frequently in patients treated with extracorporeal membrane oxygenation and may be severe. However, direct hyperbilirubinemia typically resolves without short-term sequelae. Hemolysis may be an important contributing factor.

Severe respiratory failure in neonates: mortality and morbidity rates and neurodevelopmental outcomes.

OBJECTIVE: To compare the survival, neurodevelopmental, and health outcomes of children with severe respiratory illness treated with and without extracorporeal membrane oxygenation (ECMO). DESIGN: Prospective collection of clinical and demographic data of all neonates reaching illness severity criteria, with follow-up at 8 and 20 months of age. Patients were assigned to treatment by the attending physician. PATIENTS: Consecutive sample of 74 neonates during a 24-month period with an alveolar-to-arterial gradient exceeding 620 for 8 or more hours. RESULTS: Eighteen (69%) of 26 neonates treated with conventional therapy survived to 20 months, in comparison with 43 (90%) of 48 neonates treated with ECMO. The conventionally treated group had significantly more chronic lung disease, longer duration of oxygen therapy, more chronic reactive airway disease, and more rehospitalizations than those treated with ECMO. Hospital charges were similar in the two groups. Macrocephaly was noted in 24% of those treated with ECMO and in none of the conventional group. Of those completing evaluation, 4 (24%) of 17 conventionally treated survivors and 20 (26%) of 38 ECMO-treated survivors had neurodevelopmental impairment. CONCLUSION: Survivors of severe neonatal respiratory illness have significant pulmonary and neurodevelopmental impairment, regardless of the treatment used. Neonates treated with ECMO had neurodevelopmental outcomes similar to those of patients treated conventionally, but better pulmonary outcomes.