Typically affects only a segment of the hemidiaphragm
Is due to incomplete muscularisation of the diaphragm with a thin membranous sheet replacing the normal diaphragmatic muscle.
Over time this region stretches and on inspiration does not contract normally.
Sudden rupture can occur with increase in intra-abdominal pressure (e.g. coughing, straining during light anesthesia or extubation etc)
True rupture (if it happens) – Effects:
Mass effect of the abdominal viscera–>direct compression of the heart, mediastinal shift
Compression of vena cava and pulmonary veins–> impairs venous return, decreased cardiac output.
So we should maintain adequate depth of anaesthesia
Avoid Nitrous oxide (expansion of intra-abdominal viscera can impair the circulation and respiration)
Reference: Anaesthetic Management of an Adult Patient with Diaphragmatic Eventration
Azhar Rehman*, Zafar Ali Mirza, Saad Yousuf and Asma Abdus Salam
