2025 Southeastern Residency Conference

Title: Effect of Antidepressant Continuity on Analgosedation in Mechanically Ventilated Patients

Authors: Isabelle Perling, Sarah Blackwell, Kenda Germain, John Michael Herndon

Objective: Assess the effect of antidepressant continuity or discontinuity on analgosedation in mechanically ventilated patients. 

Self Assessment Question: True or False: Abrupt cessation of antidepressants can cause antidepressant discontinuation syndrome that typically occurs in patients using SSRI or SNRI medications with short half-lives.

Background: Selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs) are first line treatment options for depression and anxiety and are used for many other psychiatric disorders. In critically ill patients with mental disorders, psychiatric symptoms may be heightened due to a change in environment and physical condition. Despite this, many antidepressants are not continued in the critical care setting for various reasons. Abrupt cessation of antidepressants can cause antidepressant discontinuation syndrome (ADS), with symptoms including agitation, mood changes, insomnia, dizziness, nausea, and vomiting. ADS has a mean onset of two days after discontinuation and is most common in patients using agents with short half-lives. The syndrome can mimic hyperactive intensive care unit (ICU) delirium, which may lead to increased sedative doses to maintain goal sedation, while the underlying cause is left untreated.

Methods: This is a single center, retrospective chart review in patients who were on SSRI or SNRI therapy prior to a hospitalization where they were subsequently intubated. Included patients were 18 years of age or older, receiving outpatient SSRI or SNRI therapy prior to hospitalization, and initiated on mechanical ventilation within 48 hours of admission. Patients with current substance abuse, need for deeper sedation, acute neurological events, chronic invasive mechanical ventilation, pregnancy, or incarceration were excluded. Patients who restarted SSRI or SNRI therapy between 49 and 72 hours were also excluded. Outcomes were compared between patients who resumed their SSRI or SNRI within 48 hours of intubation and patients for whom their SSRI or SNRI was held for more than 72 hours after intubation. The primary endpoint was the dose of IV analgosedation at 72 hours represented by the fraction of IV sedation score (FISS). FISS is a novel scoring system created to compare analgosedation medications and doses for patients on various agents. It is calculated by dividing the dose of each analgosedation agent by the typical maximum dose at the facility. Each of these are then added together to create the numerical FISS. Secondary endpoints included FISS at 24 and 48 hours, RASS at 24, 48, and 72 hours, ICU and hospital lengths of stay, duration of mechanical ventilation, and duration of IV analgosedation. Statistical tests included the student’s t-test and the Wilcoxon rank sum test.

Results: Forty patients were analyzed. FISS was similar between patients who continued their antidepressant and the discontinuity group at 72 hours post intubation, 0.95 ± 1.02 vs. 0.60 ± 0.66 (p = 0.194). There was no difference in FISS at 24 and 48 hours, RASS, ICU and hospital LOS, and duration of mechanical ventilation or analgosedation.

Conclusion: Antidepressant continuity did not result in a difference in analgosedation needs or other outcomes. The novel FISS offers a practical way to compare analgosedation needs across various agents but needs external validation for external use.

Contact information: isabelle.perling@orlandohealth.com