A timed reexpansion inspiratory manoeuvre (TRIM) for treating oxyhaemoglobin desaturation in children following a period of apnoea-studies in an animal model

Our clinical experience has shown that the use of a constant distending airway pressure of 30 cm water for 10 s, termed a timed reexpansion inspiratory manoeuvre (TRIM), is often successful in correcting oxyhaemoglobin desaturation in anaesthetized children. The aim of this study was to assess the efficacy of TRIM in lambs. Following a standard relaxant anaesthetic, ventilation was stopped and oxyhaemoglobin saturation allowed to fall to 70% and the time taken to return to baseline was compared between three groups. The median time was 42.5 s when ventilation was restarted with 33% oxygen in nitrous oxide (33% group), 30 s when ventilation was restarted with 100% oxygen (100% group) and 22.5 s with a TRIM before restarting ventilation with 33% oxygen in nitrous oxide (TRIM group). The correction of desaturation was more rapid in the TRIM group compared with the 33% group ( P