Effects of Barbiturates on the body are listed here. Thiopentone decreases the tidal volume and the effect on respiratory rate is biphasic ranging from tachypnea during light anesthesia to a progressive slowing of respiration with deepening anesthesia. However, like propofol, functional residual capacity is not reduced by thiopentone.
Effects of Barbiturates on the body administered IV for the induction of anesthesia produce dose-dependent depression of medullary and pontine ventilatory centers. It inhibits both isocapnic hypoxia and hypercapnia induced ventilatory drive.
Apnea occurs in the presence of other depressant drugs used for preoperative medication. Resumption of spontaneous ventilation after a single IV induction dose of barbiturate is characterized by a slow frequency of breathing and decreased tidal volume.
One of the effects of barbiturates on the body is that the thiopental produces transient bronchospasm, which may be blocked by atropine pretreatment. The mechanism is still not clear. It worsens histamine-induced or serotonin receptor mediated bronchoconstriction.
Laryngeal reflexes and the cough reflex is not depressed until large doses of barbiturates have been administered. Gagging, laryngospasm, head movement and difficulty in insertion of the laryngeal mask airway are more common using thiopentone than propofol. Induction with thiopental and the effects of barbiturates on the body causes increased respiratory resistance after tracheal intubation than propofol