In the immediate post operative period, the common cause of respiratory insufficiency could be because of the following except

Causes of Acute Post-operative shoness of breath MI and hea failure Chest infections Pulmonary embolism Exacerbation of asthma or COPD In mild hypovolemia, the systemic blood circulation is maintained by shifting the blood from splanchnic circulation to the systemic circulation Healthy volunteers could have 10-15% of their blood volume removed with no significant change in hea rate, BP, cardiac output or blood flow to the splanchnic bed Ref: Bailey and love 27th edition Pgno : 292