Pharmacodynamics of nitrous oxide are discussed below:
Pharmacodynamics of nitrous oxide includes the cardiovascular system as well. Nitrous oxide is a myocardial depressant and reduces the cardiac output. This is offset by an increase in sympathetic nerve activity resulting in peripheral vasoconstriction and thereby a minimal change in blood pressure. This effect also tends to counter the hypotensive effect of inhaled vapours. It is supposed to stimulate the pre-ganglion nerves and increases noradrenaline concentrations, urinary catecholamines and peripheral resistance.
Respiratory system and the effect of pharmacodynamics of nitrous oxide is also an important topic to be discussed. Nitrous oxide is non-irritant to the airway and is useful as a supplement to inhalation agents, it increases the uptake of volatile agent as well as reducing the MAC of the accompanying volatile agent.
While studying Pharmacodynamics of nitrous oxide , we also come across the different diseases. In respiratory diseases it should be used with caution, it may expand the lung bullae. It does not alter the ventilatory response to CO2. During recovery, 02 should be supplemented because of diffusion hypoxia. There may be reduction in hypoxic pulmonary vasoconstriction, which may increase right to left shunt during one lung ventilation.
Central nervous system and the pharmacodynamics of nitrous oxide : There may be increase in CBF and ICP especially iii presence of tumours or head injury. If.air pockets are left within the skull during surgery, N20 may diffuse into the pockets following closure of the wound. There is an increase in cerebral metabolism. Increasing
Pharmacodynamics of nitrous oxide studies show that N2O concentrations results in reduction in amplitude of visual and somatosensory evoked potentials; no evidence of seizure activity is seen on EEG.
Other effects: N20 does not produce muscle relaxation or potentiates the action of muscle relaxants. It has little effect on hepatic or gastrointestinal function.