Psychological and psychiatric disturbances occur frequently in mechanically ventilated patients, and cause patients, their loved ones, and their caregivers considerable distress. This chapter familiarizes the reader with commonly observed psychological and psychiatric symptoms in ventilated critically ill patients; briefly discusses the challenge of making a psychiatric diagnosis in the context of the ventilated patient; and describes what is known of the three disorders most commonly described in this patient population: delirium, depression, and posttraumatic stress disorder.
Traditional psychological and psychiatric assessments in the adult patient rely on the patient’s ability to engage in conversation. Baseline psychological health and personality, a patient’s relationship with his or her acute or chronic illness, a patient’s emotional response to it, and the clinical context in which the patient is placed are typically considered in this evaluation. Assessment of the psychological and psychiatric state of a mechanically ventilated patient is hindered by the presence of an endotracheal tube, which makes verbal communication impossible. A tracheotomy with a talking valve, and a face mask, also limits speech. Beyond problems of verbal communication, the sudden and dramatic onset of a ventilated patient’s illness, the use of pharmacologic sedation, the layout of an intensive care unit (ICU), and a critical care physician’s unfamiliarity with psychological assessments have hampered descriptions of psychiatric and psychological issues.
Psychiatric diagnoses are made on the basis of clinical criteria. These criteria were, for many decades, highly variable depending on a school of thought and geographical provenance. Lobotomies, incremental electroshock therapy to re-create neuropsychiatric normalcy, and insulin-coma treatments exposed psychiatric professionals to scientific and public criticism. Over the last 40 years, psychiatric diagnoses have been structured more rigorously by experienced psychiatrists based on symptom and disease classifications through the use of systems such as the International Classification of Diseases (ICD) from the World Health Organization, and the Diagnostic and Statistical Manual of Mental Disorders (DSM) from the American Psychiatric Association. The tenth revision of the International Statistical Classification of Diseases and Related Health Problems (ICD-10) was published in 1991; the fourth revision of the Diagnostic and Statistical Manual of Mental Disorders, DSM-IV-TR, was published in 2000. The ICD-11 is expected in 2011 and the DSM-V update is anticipated in 2013.
The ICD-10 and the DSM-IV-TR rely on diagnostic criteria compiled by expert psychiatrists and, in the case of the DSM-IV, on the basis of described and published patient symptoms. Two problems become apparent when applying these diagnostic criteria to critically ill patients. The first is the challenge of applying diagnostic criteria to a mechanically ventilated patient if the symptom constellations have been gathered in a different—usually ambulatory—population. Apathy, for instance, a feature of depression, may be expected in a septic ventilated patient receiving propofol, making its value as a diagnostic criterion of depression in this context uncertain. The second is that these DSM or ICD criteria have not been investigated in terms of validity in ventilated patients, whether acutely or ...