Alternatives to ECMO

Extracorporeal Membrane Oxygenation with Veno-Venous Bypass and Apneic Oxygenation for Treatment of Severe Neonatal Respiratory Failure

Seven newborn infants with life-threatening respiratory failure were treated with veno-venous (V-V) extracorporeal lung support and apneic oxygenation after maximal ventilatory and pharmacological treatment failed. Diagnosis were meconium aspiration syndrome in 3 cases, respiratory distress syndrome in 2, sepsis in 1, congenital diaphragmatic hernia in 1. Before ECMO 6 infants received tolazoline, 4 surfactant, 3 high frequency ventilation, 1 prostaglandin E, 1 epoprostenol, 2 nitric oxide. Newborns were highly hypoxemic at admission and all but one underwent rescue cannulation. V-V bypass was performed with a single lumen single cannula and tidal flow was generated by an alternating clamp using a non-occlusive roller pump. The mean duration of bypass was 162, 4±162.3 hours and infants were extubated 94.5±74.8 hours after decannulation. Five newborns survived and two died. Growth and neurologic development of the older children is normal. The extracorporeal lung support with V-V bypass associated with apneic oxygenation was effective in reversing severe neonatal respiratory failure unresponsive to maximal ventilatory and pharmacological support. An early referral, prior to meeting ECMO criteria, is important in order to avoid hypoxic complications preceding ECMO.

Simulation models in the planning of health care facilities: an application in the case of neonatal extracorporeal membrane oxygenation

OBJECTIVES

To investigate whether modelling techniques can be used in the planning of health care facilities for patients requiring neonatal extracorporeal membrane oxygenation (ECMO).

METHODS

In a micro-simulation model the number of patients that will have to be referred to facilities abroad is estimated for any number of neonatal ECMO patients presenting annually for treatment in The Netherlands, and any number of ECMO facilities. The inputs to the model consist of the number of ECMO facilities, the number of patients presenting annually, the duration of treatment and the date on which patients present for ECMO treatment. The model is estimated on data from The Netherlands for 1992, during which 29 patients were treated in three facilities. Several future scenarios are modelled, principally one in which a potential increase to 56 patients per year is foreseen.

RESULTS

The model indicates that, if such an increase takes place, no additional ECMO facilities will be necessary in The Netherlands if between three and four referrals annually to centres outside the region (or abroad) are considered acceptable and feasible. In that situation, it is expected that on 22 occasions each year two patients will be treated simultaneously, for a total of 81 days. On ten occasions, all three facilities will be occupied at the same time, for 21 days in total. On 199 days, at least one of the facilities will be occupied.

CONCLUSION

The current study shows that the acceptability and feasibility of patient referrals to ECMO centres abroad is an important issue which health care planners will have to consider. The study also shows that modelling techniques can provide information that is useful to policy-makers in the planning of health care facilities.

Occupational exposure during nitric oxide inhalational therapy in a pediatric intensive care setting

OBJECTIVE

To determine the amount of occupational exposure to nitric oxide (NO) and nitrogen dioxide (NO2) during NO inhalational therapy.

DESIGN

In a standard pediatric intensive care room, 800 ppm NO was delivered to a high-frequency oscillator and mixed with 100% O2 to obtain 20 ppm NO in the inspiratory gas flow. NO and NO2 concentrations in room air were measured using a chemiluminescence analyzer. Air samples were taken from a height of 150 cm at a horizontal distance of 65 cm from the ventilator in a nonventilated and in a well-ventilated room with and without an expiratory gas exhaust under normal intensive care environmental conditions.

SETTING

Pediatric intensive care unit in a university children's hospital.

MEASUREMENTS AND RESULTS

Maximal concentrations of NO and NO2 were reached after 4 h NO use. Without exhaust, in a nonventilated room, environmental NO and NO2 concentration rose to a maximum of 0.462 and 0.064 ppm, respectively. With the use of an expiratory gas exhaust, NO and NO2 concentrations were 0.176 and 0.042 ppm, respectively. With normal air-conditioning, these values were 0.075 and 0.034 ppm, respectively, without the use of an expiratory gas exhaust. With expiratory gas exhaust added to normal air-conditioning, values for NO and NO2 were 0.035 and 0.030 ppm, respectively.

CONCLUSIONS

The use of 20 ppm NO, even under minimal room ventilation conditions, did not lead to room air levels of NO or NO2 that should be considered toxic to adjacent intensive care patients or staff. Slight increases in NO and NO2 concentrations were measurable but remained within occupational safety limits. The use of an exhaust system and normal room ventilation lowers NO and NO2 concentrations further to almost background levels.