Abstract
To ensure the utmost safety, it is recommended that prior checking the machine and breathing systems as mandatory. Certain factors beyond the control of the anaesthesiologist lead to the operative room incidences jeopardizing the anaesthetised patient which otherwise cannot be prevented by prior custom checking. Delayed occlusion of a spiral reinforced endotracheal tube during prone position anaesthesia and faulty dual control knob of fresh gas flow of an anaesthesia machine leading to inadequate ventilation are given as examples. In above events, a prior checking the machine or tracheal tube, could not prevent its occurrence. However, use of a deputy of the objects resulted in uneventful anaesthesia.