Introduction

As the name implies, the intensive care unit (ICU) is where a hospital's sickest patients who require accelerated and concentrated care are admitted. Many of these patients, an estimated 33% of all admissions, are admitted for respiratory failure of one etiology or another and subsequently are intubated and placed on mechanical ventilatory control. Part of the standard of care for intubation is to sedate the patient continuously to reduce pain and anxiety; decrease oxygen consumption and the body's stress response; prevent patient-ventilator desynchrony; reduce adverse neurocognitive impacts such as depression and post-traumatic stress disorder and ventilator-associated events including pneumonia and tracheostomy, and reduce total nursing requirements.

Mechanically ventilated patients frequently experience pain from mechanical ventilation, endotracheal suctioning, indwelling catheters, surgical incisions, and repositioning in bed.[1] The medications used to initiate and maintain sedation in an intensive care unit include benzodiazepines (eg, diazepam, lorazepam, and midazolam), opioid analgesics (eg, fentanyl, hydromorphone, morphine, remifentanil), propofol, dexmedetomidine, ketamine, and antipsychotics (eg, haloperidol, quetiapine, and ziprasidone). No sedative is found to be superior in efficacy or mortality. However, The Society of Critical Care Medicine guidelines recommend avoiding benzodiazepines due to evidence of a longer duration of intubation. The choice of which sedative is best lies in the practitioner's clinical assessment of individual patient scenarios, weighing the risk/benefit profile of the medicine for each patient.

Regardless of which sedative agent was utilized, total continuous sedation was found to be associated with an extension of the total length of intubation and increased length of the ICU stay and limited the ability to assess the mental status of the patient properly, increasing the risk of delirium, and suppressed brainwave function seen on EEG, linking to increased 6-month mortality. It was assessed that daily, short-term cessation of sedation, a "sedation vacation," improved patient care outcomes. As per the evidence-based practice, sedation should be interrupted at least every day in mechanically ventilated patients to evaluate the patient's need to remain on intravenous continuous sedation.[2] Benefits of this approach include the ability to appropriately titrate sedation, which reduces the length of ICU stay, time on mechanical ventilation, risk of ventilator-associated lung infections, and need for neurological diagnostic tests related to oversedation.[3]

A study conducted on 80 patients revealed that a daily sedation vacation protocol in patients with intravenous sedation reduced the incidence of ventilator-associated pneumonia (VAP). Therefore, nurses are recommended to use the daily sedation vacation protocol to prevent VAP.[4]

Sedation vacations were first introduced in 2000 with a study by J.P. Kress et al. published in the New England Journal of Medicine and recognized as a medical necessity for standard practice within the ICU to wean patients from mechanical ventilation. The study of spontaneous-awakening trials showed that daily sedation interruptions improved the time to extubation of 64 patients by approximately 2 days, which reduced the total admission time in the ICU by 3.5 days. Two separate trials further reinforced this study: the Awakening and Breathing Controlled trial in 2008, titled the "wake up and breathe" protocol, and the No Sedation in Intensive Care Unit Patients trial in 2010. Both supporting trials investigated the impacts of imposing a protocol to evaluate and reduce sedation in a structured format and found that spontaneous breathing trials and sedation vacations reduced ventilatory-dependent days and ICU admission days compared to nonstructured or no-sedation vacation protocols.[5][6][7][8]

Issues of Concern

Sedation vacations can sometimes result in complications, which should be addressed accordingly. When sedation is turned off, the patient may not remember that they were intubated and may be unaware of all the tubes and lines going into their body. Upon awakening, they may be confused and anxious and pull out the endotracheal tube or other deep lines. This may result in laryngeal injury/laryngeal edema, and if not addressed promptly, it can lead to respiratory failure and may result in death. If the patient is very anxious after the sedation is turned off, the sympathetic drive might be very high, resulting in tachycardia and high blood pressure. High blood pressure, especially in elderly persons, can cause a stroke or myocardial infarction.[9][10]

Clinical Significance

Sedation vacation is a balancing act of tightly titrating the sedative dose to provide agitation-free, comfortable sedation in the lowest dosage possible. It is patient-specific, as various disease processes and patient tolerances necessitate different doses of medicine. Two primary scale systems are utilized to assess the degree of sedation and agitation present during a sedation vacation withdrawal period to determine the vacation's success versus the need for continued sedation. These are the RIker Sedation-Agitation Scale (SAS) and the Richmond Agitation-Sedation Scale (RASS).[11]

SAS places a numerical value on a patient's mental status, where 1 is an unarousable state, 4 is a calm and cooperative patient, and 7 is a dangerously agitated or combative patient. RASS has a similar parameter of mental status assessment, with -5 being unarousable, 0 being alert and calm, and +4 being a dangerously agitated or combative patient. These scales provide input when determining how aggressively protocol is implemented. Baseline mental status is also assessed by the ability to follow commands, including eye-opening and tracking, hand squeezing, or tongue protrusion.[12][13]

Several proposed guidelines offer guidance on assessing and addressing sedation vacations. One such protocol with proven benefit is the Wake-Up and Breathe protocol, which combines spontaneous awakening trials where sedative medicine is withdrawn to awaken the patient with spontaneous breathing trials where the body's readiness to extubate from mechanical ventilation is assessed in a stepwise fashion.[14]

The ability to undergo a spontaneous awakening trial is assessed for safety, specifically monitoring for active seizures, active alcohol withdrawal, agitation, use of paralytic agents, active myocardial ischemia, and elevated intracranial pressure. Spontaneous awakening trials cannot be attempted if any are present and should be reevaluated in 24 hours. If none are present, a sedation vacation should be attempted. Markers of failure include agitation per SAS or RASS scales, pain, a respiratory rate greater than 35 breaths per minute, oxygen saturation less than 88%, respiratory distress, or acute cardiac arrhythmia. Any markers of failure should prompt the restarting of sedatives at 50% of the previous dosage with a reassessment within 24 hours.

If spontaneous awakening is successful, a spontaneous breathing trial should be performed. Markers that it is safe to do so include no agitation, oxygen saturation greater than 88%, FiO₂ less than 50%, PEEP less than 8 cm H₂O, no active myocardial ischemia, minimal vasopressor requirements, and good inspiratory efforts. If any are present, restart sedation and reevaluate in 24 hours. Signs of spontaneous-breathing trial failure include respiratory rate greater than 35 or less than 8 breaths per minute, oxygen saturation less than 88%, signs of respiratory distress, mental status changes, or acute cardiac arrhythmia. If none of these are present, it is appropriate to consider the extubation of the patient. If the patient has been intubated for more than 48 hours and has no cuff leak, a steroid dose can be given 4 to 5 hours before extubation, and another dose can be given 4 to 5 hours after extubation. This has been shown to decrease the rate of reintubation and laryngeal edema.[15]

The reason for sedation vacation or breathing trial failing should be identified and addressed accordingly. If the patient is getting agitated and is delirious, antipsychotics can be tried. If anxious, anxiolytics can be tried, or if in pain, low-dose fentanyl drip/morphine drip or patch can be administered. Patient delirium and agitation can be very well controlled on dexmedetomidine. The medication does not suppress the respiratory center; therefore, the patient can be extubated while on continuous dexmedetomidine infusion. Attention should be paid to home medications, and if clinically permitted, a patient who is on any anxiolytics, antipsychotics, or chronic pain medications should continue them while sedated or restart them in a timely fashion to prevent withdrawal.[10]

Enhancing Healthcare Team Outcomes

Mechanically ventilated patients often experience discomfort from various factors, resulting in patients requiring continuous intravenous sedation, including analgesia. A sedation vacation is needed to assess the patient's neurologic status and establish the necessity for the continuation of sedation. The evidence-based practice recommends giving the patient a break from sedation at least daily. This will lead to reduced mechanical ventilation time, decreased ICU stay length, and a lower risk of ventilator-associated pneumonia.

An interprofessional team approach is crucial in achieving the best outcomes in mechanically ventilated patients who undergo sedation vacation protocol. The critical care nursing staff and respiratory therapists play a vital role. Many quality improvement projects have revealed that adherence of the nursing staff to sedation vacation protocol achieves the best patient outcomes.