Pre-operative stabilisation with delayed repair in congenital diaphragmatic hernia.

Congenital diaphragmatic hernia (CDH) remains one of the major challenges for paediatric surgeons and paediatric intensive care specialists. Death in patients with CDH is 30-60% worldwide due to severe pulmonary hypoplasia or pulmonary hypoplasia associated with persistent pulmonary hypertension, secondary to hypoxia, metabolic acidosis or myocardial insufficiency. Pre-operative stabilisation of CDH patients might reduce the risks of these complications. In a two-year period 16 high-risk patients with CDH (respiratory insufficiency less than 6 hrs after birth) underwent delayed surgery following a stabilisation period (mean 14 hrs). Continuous suctioning on a nasogastric tube resulted in total resolution of the mediastinal shift on repeat x-rays. The use of the ventilation parameters arterial alveolar oxygen gradient (A-aDO2), oxygenation index (OI) and mean airway pressure (MAP) revealed three different groups of patients: I consisting of 6 survivors, II two preventable deaths and III eight non-survivors. In this way selection of patients with CDH is possible. In patients who do not improve during the stabilisation period alternative ways of treatment have to be evaluated such as extracorporeal membrane oxygenation (ECMO), high frequency oscillation (HFO) or high frequency jet ventilation (HFJV). Application of the ventilation parameters in prospective trials of patients with CDH enables comparison between different ways of treatment in the future.

Histamine log(dose)-response curves in asthmatics. A comparison between the Wiesbadener Doppelinhalator and the De Vilbiss Model 645 nebulizer.

In 9 asthmatic patients log(dose)-response curves were obtained on 4 successive days with the Wiesbadener Doppelinhalator (WDI) and the De Vilbiss (De V) 645 nebulizer, respectively. log(dose)-response was expressed as a quadratic regression equation. From those equations the dose, causing a fall in response (FEV1) of 10% of the initial value, was obtained and defined as the provocative concentration (PC(10] or sensitivity. Moreover, the reactivity was defined as the slope of the linear regression through the steeper part of the curve. Although we compared the De V and the WDI log(dose)-response curves after correction for the different liquid output, a significantly greater sensitivity was found for the De V nebulizer. As to the reactivity, no significant differences were found. The difference in sensitivity could perhaps be explained by the fact that, as compared with the De V nebulizer, the WDI may cause a larger deposition of aerosol on the throat and the pharynx, due to the much greater linear velocity of its aerosol jet.