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 < 0.004) and the 100% group (P < 0.003). Oxyhaemoglobin desaturation due to apnoea in anaesthetized lambs is more effectively treated with a TRIM than by increasing the inspired oxygen fraction.
McDonald
P F
PF
Department of Paediatric Anaesthesia, Women's and Children's Hospital, North Adelaide, South Australia.
van der Walt
J H
JH
Parnis
S J
SJ
D000768:Anesthesia, General / Q000009:adverse effects*; D000818:Animals; D000833:Animals, Suckling; D001049:Apnea / Q000097:blood / Q000628:therapy*; D002648:Child; D006801:Humans; D007432:Intraoperative Period; D008176:Lung Volume Measurements; D010102:Oxygen Inhalation Therapy; D010108:Oxyhemoglobins / Q000378:metabolism*; D012121:Respiration, Artificial; D012756:Sheep
D010108:Oxyhemoglobins