Acute Stress Disorder

Definition

Acute stress disorder (ASD) is an anxiety disorder characterized by a cluster of dissociative and anxiety symptoms occurring within one month of a traumatic event. (Dissociation is a psychological reaction to trauma in which the mind tries to cope by "sealing off" some features of the trauma from conscious awareness).

Description

Acute stress disorder is a new diagnostic category that was introduced in 1994 to differentiate time-limited reactions to trauma from post-traumatic stress disorder (PTSD).

Causes and symptoms

Acute stress disorder is caused by exposure to trauma, which is defined as a stressor that causes intense fear and, usually, involves threats to life or serious injury to oneself or others. Examples are rape, mugging, combat, natural disasters, etc.

The symptoms of stress disorder include a combining of one or more dissociative and anxiety symptoms with the avoidance of reminders of the traumatic event. Dissociative symptoms include emotional detachment, temporary loss of memory, depersonalization, and derealization.

Anxiety symptoms connected with acute stress disorder include irritability, physical restlessness, sleep problems, inability to concentrate, and being easily startled.

Key terms

Depersonalization — A dissociative symptom in which the patient feels that his or her body is unreal, is changing, or is dissolving.

Derealization — A dissociative symptom in which the external environment is perceived as unreal.

Dissociation — A reaction to trauma in which the mind splits off certain aspects of the trauma from conscious awareness. Dissociation can affect the patient's memory, sense of reality, and sense of identity.

Trauma — In the context of ASD, a disastrous or life-threatening event.

Diagnosis

Diagnosis of acute stress disorder is based on a combination of the patient's history and a physical examination to rule out diseases that can cause anxiety. The essential feature is a traumatic event within one month of the onset of symptoms. Other diagnostic criteria include:

The symptoms significantly interfere with normal social or vocational functioning
The symptoms last between two days and four weeks.

Treatment

Treatment for acute stress disorder usually includes a combination of antidepressant medications and short-term psychotherapy.

Prognosis

The prognosis for recovery is influenced by the severity and duration of the trauma, the patient's closeness to it, and the patient's previous level of functioning. Favorable signs include a short time period between the trauma and onset of symptoms, immediate treatment, and appropriate social support. If the patient's symptoms are severe enough to interfere with normal life and have lasted longer than one month, the diagnosis may be changed to PTSD. If the symptoms have lasted longer than one month but are not severe enough to meet the definition of PTSD, the diagnosis may be changed to adjustment disorder.

Patients who do not receive treatment for acute stress disorder are at increased risk for substance abuse or major depressive disorders.

Prevention

Traumatic events cannot usually be foreseen and, thus, cannot be prevented. However, in theory, professional intervention soon after a major trauma might reduce the likelihood or severity of ASD. In addition, some symptoms of acute stress disorder result from biochemical changes in the central nervous system, muscles, and digestive tract that are not subject to conscious control.

Resources

Books

Corbman, Gene R. "Anxiety Disorders." In Current Diagnosis, edited by Rex B. Conn, et al. Vol. 9. Philadelphia: W. B. Saunders Co., 1997.

Eisendrath, Stuart J. "Psychiatric Disorders." In Current Medical Diagnosis and Treatment, 1998, edited by Stephen McPhee, et al., 37th ed. Stamford: Appleton & Lange, 1997.

acute

[ah-kūt´]

1. sharp.

2. having severe symptoms and a short course. Some serious illnesses that were formerly considered acute (such as myocardial infarction) are now recognized to be acute episodes of chronic conditions.

acute care the level of care in the health care system that consists of emergency treatment and critical care. Called also secondary care.

acute coronary syndrome a classification encompassing clinical presentations ranging from unstable angina through myocardial infarctions not characterized by alterations in Q waves; the classification sometimes also includes myocardial infarctions characterized by altered Q waves.

acute respiratory distress syndrome (ARDS) a group of symptoms accompanying fulminant pulmonary edema and resulting in acute respiratory failure; called also shock lung, wet lung, and many other names descriptive of etiology or clinical manifestations. Many etiologic factors have been associated with ARDS, including shock, fat embolism, fluid overload, oxygen toxicity, fluid aspiration, narcotic overdose, disseminated intravascular coagulation, multiple transfusions, inhalation of toxic gases, diffuse pulmonary infection, and systemic reactions to sepsis, pancreatitis, and massive trauma or burns.

ARDS is characterized clinically by dyspnea, tachypnea, tachycardia, cyanosis, and hypoxemia. Pa_O_₂/FI_O_₂ remains low (below 2 cc) even with oxygen therapy at high oxygen concentrations. The lung compliance is decreased so that the lung is stiffer and more difficult to ventilate. Chest radiographs show signs of bilateral interstitial and alveolar edema. Cardiac filling pressures are normal, and the pulmonary capillary wedge pressure is below 18 torr.

Most authorities consider that the syndrome has three phases or stages that characterize its progression: the exudative stage, the fibroproliferative or proliferative stage, and the resolution or recovery stage. The exudative stage comes first, two to four days after onset of lung injury, and is distinguished by the accumulation of excessive fluid in the alveoli with entrance of protein and inflammatory cells from the alveolar capillaries into the air spaces. The fibroproliferative stage comes second and is characterized by an increase in connective tissue and other structural elements in the lungs in response to the initial injury. It begins between the first and third weeks after the initial injury and may last up to ten weeks. Microscopic examination reveals lung tissue that appears densely cellular. The patient is at risk for pneumonia, sepsis, and pneumothorax at this time. The third stage is the resolution or recovery stage. During this stage the lung reorganizes and recovers, although it continues to show signs of fibrosis. Lung function may continue to improve for as long as six to twelve months or even longer, depending on the precipitating condition and severity of the injury. It is important to remember that there are often different levels of pulmonary recovery in patients with ARDS.

Some authorities refer to a fourth phase or stage of ARDS, the period after the resolution or recovery stage. Some patients continue to experience health problems caused by the acute illness, such as coughing, limited exercise tolerance, and fatigue. Anxiety, depression, and flashback memories of the critical illness may also occur and be similar to posttraumatic stress disorder.

Treatment and Patient Care. Mechanical ventilation must be begun at the first signs of hyperventilation and hypoxemia, before obvious signs of respiratory distress develop. A cuffed endotracheal tube or tracheostomy tube is used to maintain an airway. The patient is ventilated at the lowest oxygen concentration that maintains the arterial oxygen saturation (Sa_O_₂) at 90 per cent. positive end-expiratory pressure (PEEP) or continuous positive airway pressure (CPAP) may be used to increase the number of alveoli that remain open at the end of exhalation and thus decrease pulmonary shunt. hemodynamic monitoring, using a swan-ganz catheter, is done to measure cardiac output, pulmonary capillary wedge pressure, and right atrial wedge pressure. An arterial line is placed to continuously monitor blood pressure and measure arterial blood gases. A diuretic such as furosemide (Lasix) may be administered to reduce fluid volume overload and pulmonary edema. If infection develops, antibiotics are administered. Hemodynamic parameters, arterial blood gas levels, intake and output, breath sounds, vital signs, inspiratory pressure, tidal volume, inspired oxygen concentration, and end-expiratory pressure are all continuously monitored.

acute situational reaction a transient, self-limiting acute emotional reaction to severe psychological stress. See acute stress disorder, adjustment disorder, posttraumatic stress disorder, and brief reactive psychosis.

acute stress disorder an anxiety disorder characterized by development of anxiety, dissociation, and other symptoms within one month following exposure to an extremely traumatic event, the symptoms including reexperiencing the event, avoidance of trauma-related stimuli, anxiety or increased arousal, and some or all of the following: a subjective sense of diminished emotional responsiveness, numbing, or detachment, derealization, depersonalization, and amnesia for aspects of the event. If persistent, it may become posttraumatic stress disorder.

acute stress reaction acute situational reaction.

acute stress disorder

1. development of characteristic symptoms within the first 4 weeks after a psychologically traumatic event that was outside the range of usual human experience. These include dissociative phenomena (numbing or detachment), decreased awareness of surroundings, derealization, depersonalization, and selective amnesia; reexperiencing the event and attempting to avoid stimuli reminiscent of the trauma, marked anxiety, and various symptoms of autonomic arousal.

2. a DSM diagnosis that is established when specified criteria are met.

acute stress disorder

A psychiatric disorder that occurs within a month after experiencing or witnessing a traumatic event, characterized by symptoms such as flashbacks or amnesia, problems with concentration and sleep, emotional numbness, and persistent negative mood.

a·cute stress dis·or·der

(ASD) (ă-kyūt stres dis-ōrdĕr)

Development of characteristic symptoms within the first 4 weeks after a psychologically traumatic event that was outside the range of usual human experience.