NUR1 233 Lecture : Chapter 24.docx
Document Summary
When cutting umbilical cord most cirtical and immediate adjustment is establishment of respirations. Vaginal birth: some lung fluid is squeezed from trachea and lungs. Cesarean birth: some lung fluid may be retained within alveoli. With first breath of air, newborn begins a dynamic sequence of cardiopulmonary changes. Chemoreceptors: in aorta and carotid bodies initiate neurological reflexes when po2 falls or pco2 rises and ph. Initial breathing: result of a reflex triggered by pressure changes, cool air temp, noise, light, etc. falls. I minute of birth: exaggerated respiratory reaction and the infant takes the first gasping breath and cries. Later: respirations established shallow and irregular 30-60 breaths/min with periods of periodic breathing that include pauses in respirations lasting less than 20s. Periodic breathing: occur most often during active rem sleep cycle and decrease in frequency and duration with age. Anetic periods: lasting 20s or longer indicatoin of a pathological process and should be carefully evaluated.