Anatomy for Anaesthesia in Paediatric Patients

Abstract

Anesthesia for children is attenuated by the changes that occur during growth anddevelopment. The dose of the drug is affected by the size and maturation processesof purification, as well as by the changing body composition that occurs with age.All organ systems undergo these maturation changes and most are completed in thefirst years of life. Normal physiological variables in childhood and childhood are quitedifferent from those of adults. The central nervous, cardiovascular and respiratorysystems are particularly important. Brain immaturity and plasticity impact drug sensitivity,pain responses and behavior and increase the potential damage of apoptosiswith anesthesia. The heart experiences a transition from fetal to adult circulationduring the first weeks of life. Congenital defects not diagnosed are not uncommon.The newborn is very susceptible to conditions that trigger an increase in pulmonaryvascular resistance, with reversion to fetal circulatory patterns. The anatomy and respiratorymechanics affect the apnea propensity, the maintenance of the airways, theartificial ventilation modalities, the absorption of inhalant agents and the size of thetracheal tubes. The metabolic rate and oxygen requirements increase with age. Thisphysiology influences various aspects that include the desaturation rate during apnea,hypoglycemia during hunger, cardiac output, drug metabolism, fluid requirements andheat production or loss.Key words: Physiology–respiratory system–Anatomy–bronchomotor tone–functionalresidual capacity–tracheobronchial tree–ventilationperfusion