INTERRUPTED VERSUS CONTINUOUS SEDATION DURING MECHANICAL VENTILATION IN THE INTENSIVE CARE UNIT

Abstract

Sedation plays an important role in the care of the critically ill patient. In the ICU,sedation is indicated in anxiety and related disorders (agitation and delirium), it is also used to induce amnesia, to decrease oxygen consumption, andto facilitate care-intubation, mechanical ventilation and nursing care.The ideal sedative drug in the ICU will be inexpensive and have minimal adverse effects. The most important sedatives frequently used in the ICU are: Benzodiazepines (Midazolam, Lorazepam, Diazepam), Propofol, Opioids (Morphine, Fentanyl, Remifentanil), Haloperidol, and α2-Agonists (Dexmedetomidine, Clonidine). Many methods have been used to assess the sedation level of patients in ICUs, both subjectiveand objective methods.

Sedative agents can be administered as boluses when required, or by continuous infusion. Sedation with continuous intravenous sedatives is often used in the early phase of critical illness, when symptoms are most acute and care is most interventional. Sedation protocols are commonplace within ICU environments and provide a structured framework that guides seda¬tive administration and monitoring. Protocolized use of sedatives may help strike a balance between inadequate and excessive sedation and thereby avoid complications.

During mechanical ventilation there is an important interaction between the patient and ventilator that is influenced by factors related to the patient, and factors related to the ventilator. Patient-ventilator asynchrony is a frequently encountered problem in mechanically ventilated patients. It is a mismatching between the patient’s breaths and ventilator-assisted breaths, as well as the inability of the ventilator’s flow delivery to match the patient’s flow demand, and is associated with adverse outcomes. Sedation is used frequently to reduce patient-ventilator asynchrony.

The strategy of daily interruption of sedative drugs allowed a focused downward titration of sedative infusion rates over time, streamlining administration of these drugs and minimizing the tendency for accumulation, providing acceptable sedation while minimizing adverse effects. Interrupted sedation during mechanical ventilation has more advantages and less disadvantages than continuous sedation.