Text V. Withdrawal of Ventilatory Support

a) Weaning or withdrawal. Ventilatory support is a technique for testing the infant to see how well he manages without the ventilator. “Weaning” is a misleading term because it inmplies that you may be able to teach the patient to get along without the ventilator.

b) Individualization. A plan for withdrawal of ventilatory support is necessary. Reduce that parameter which is considered to be most excessive and most hazardous to the patient, and reassess arterial blood gases.

c) CPAP at 4 to 6 cm water alone usually can be tried when a rate of 10 to 12 per minute is tolerated by the infant. The inspired oxygen concentration is kept the same or raised by 5%. At this point an arterial blood gas value is obtained in 20 to 30 minutes. Most infants who weigh is less than 1,250 gm do not tolerate CPAP, but do well if extubated when ventilator settings are low (12-14 cm H2O inspiratory pressure and a rate of 12-14 per minute).

d) Caution. When using slow rates (10 to 15 breaths per minute), avoid excessive inspiratory times. An inspiratory time of 0.4 seconds should be adequate and should not exceed 0.6 seconds. Thus, at a rate of 15 breaths per minute the I:E ratio should be 1:3 to 1:10. Remember, slowing the rate by increasing the inspiratory time increases mean airway pressure. When ordering a rate change, be sure to specify a change in inspiratory time, expiration time, or both.

e) Deterioration of the infant’s blood gas status during the above process requires return to the previously effective ventilator settings. Reassess the infant for complications of ventilatory therapy or for a new problem such as patent ductus arteriosus, low hematocrit reading, cold stress, atelectasis, mechanical problem with the ventilatory system, etc.

28. Read and translate text VI with the help of the dictionary: