ABD – part 3

This is the third and final part of what I hope you will agree has been a fascinating short series of BLOGs by Dr RS, a UK Consultant in Emergency Medicine. My final vote of thanks to him for taking the time to do this.  If you haven’t seen the first two parts, you may want to consider reading them before launching into the final chapter –


In parts 1 and 2 the history, causes and underlying physiology were discussed. In the final piece, the treatment options available will be described, according to the current best medical evidence available, along with personal experience of treating patients presenting at various aspects of the Acute Behavioural Disturbance spectrum.

GENERAL CONSIDERATIONS

Established medical evidence for the specific treatment of this condition is extremely limited; recently the results of trials into the management of severe agitation, and observed prehospital care have been published building the evidence base (albeit in different healthcare models to the UK). Prior to this, most treatment has been transposed from the management of agitated patients as a result of psychiatric illness. As indicated by the prior two articles in this series, pertinent to the management of ABD is the recognition that this is a MEDICAL emergency, as opposed to a psychiatric one. The prehospital management of such cases would necessitate a separate article (which I am happy to provide if requested).

Initial Assessment –

The initial assessment of a patient presenting with suspect ABD is challenging, and poses risks to medical, paramedical and police staff. By definition the patient is in a delirious state, and as such unable to understand efforts to try and provide medical assistance; attempts to verbally de-escalate are ineffective, and delay urgent medical intervention. The patient is in a state of fear, and believes persons are attempting to inflict harm; this can result in resistance to the most basic of medical care (for example measuring vital signs), to intense violent outbursts resulting in injury to themselves and care providers. If brought to the Emergency Department by police, the use of handcuffs and fast straps is often necessary to facilitate transport to definitive care.

Rapid SENIOR clinical assessment, based on observations is required to establish the diagnosis (raised body temperature, rapid pulse, delirium); it is rarely of immediate practical use to obtain blood tests (a finger-stick blood glucose can be measured to exclude a low blood sugar).

Initial Management –

The primary goals of resuscitation (for this is a life-threatening condition) are to administer rapid sedation, cooling, and fluids. The practicalities of delivering these interventions can be challenging; to obtain intravenous access in a patient that is combative can be incredibly difficult due to limb movement, collapse of the veins (from dehydration), lack of veins from intravenous drug use, and the very real risk of a needlestick injury to staff. Injuries to staff, and the number of staff required to physically restrain a patient who is often incredibly strong pose additional issues.

SEDATION

The aim of sedation is to reduce the extreme agitation as a result of the chemical disturbance within the brain; this is NOT simply to make the patient “easy to manage” nor used as a punishment. Without sedation, agitation will continue to escalate to the point of cardiovascular collapse. Sedation of a patient with ABD is not without risk; consideration of loss of protective airway reflexes, and suppression of the respiratory drive leading to hypoxia (low blood oxygen levels) are the primary complications, as is a sudden loss of blood pressure (hypotension).

The choice of sedation agent has been the subject of recent research; the time of peak action, method of administration, and complications from the drugs themselves necessitates consideration. Established management of agitation for psychiatric practise utilises lorazepam (a benzodiazepine), and haloperidol (an ‘antipsychotic’ or neuroleptic) injected into the muscle. The time of onset to peak effect is usually in the region of 20 minutes; for life-threatening ABD this is time-to-effect is to protracted to have a meaningful application. Within the Emergency Department, the use of intravenous benzodiazepine medications (diazepam, lorazepam, midazolam) offer one solution, however the doses required may be considerably higher to achieve effect. The use of neuroleptic medications, may have an adjunctive role but are probably best avoided in patients with ECG changes secondary to acidosis (which may be difficult to establish).

If intravenous access is impossible to establish (or poses too great a risk to staff), the possibility of intra-osseous access can be considered (but again risks to staff, displacement of the needle, and lack of access to a suitable site can obviate its use). In such situations, the threat to life of the patient due to the need for restraint, hyperthermia (increased body temperature), and continuing acidosis may necessitate the use of intra-muscular ketamine; ketamine is an anaesthetic drug that has a rapid onset of action when given into the muscle (within 5 minutes), however a doctor must possess the necessary skills to manage a patient’s airway once administered.
The administration of emergency anaesthesia in extreme cases is often the only option to provide life-saving treatment; this is a complex task, and necessitates care from clinicians who possess the appropriate skill set. Emergency anaesthesia enables formal airway control, the administration of powerful sedation, and ventilatory support to a patient who is imminently at risk of cardiac arrest, or whose aggression and agitation is such that risk to staff and themselves is of such a severity no other options exist.

INTRAVENOUS FLUIDS

Once sedation has been achieved, it is imperative to obtain intravenous access. At this point, blood samples for the measurement of acidosis, blood electrolytes, kidney and liver function tests, and creatine kinase (to measure muscle breakdown), clotting studies, and full blood count (measuring platelets, white cells and red blood cells) should be taken. An ECG to establish any abnormal rhythm or electrical conduction abnormalities is necessary.

The administration of cooled fluids (usually saline) aids in supporting the circulation (due to fluid loss from dehydration and sweating), promoting the excretion of muscle proteins released, and cooling of the body core temperature. Usually 1 to 2 litres of fluid are required to restore fluid losses, and aid in recovery from acidosis.

The role of administering bicarbonate as a fluid in acidotic states is often advised against by the medical literature; however in cases of severe acidosis with ECG changes and low pressure unresponsive to fluid resuscitation, a dose of bicarbonate may reverse the negative effects on the heart, and this decision is usually reserved on a case-by-case basis.

COOLING

Cooling is the third aspect of the resuscitation of the patient with ABD; this is achieved by stripping the clothes, the use of ice, and cooled fluids. Paracetamol and ibuprofen will not lower the body temperature; by the reduction of agitation through sedation, the process of heat generation from muscle activity is negated.

AFTERCARE

Once past the initial resuscitation phase, the cause for the ABD requires consideration; overwhelmingly drugs of abuse are responsible and time for the body to metabolise these agents and excrete them is the only treatment necessary. On-going sedation and fluid therapy may be required to support the patient for the next 24-48 hours. In a select group of cases, severe disturbance of thought process may continue, and necessitate specialist psychiatric assessment and treatment.

To conclude, the incidence of acute behavioural disturbance within the UK is increasing. Whilst controversial, and some clinicians may refute the existence of the condition, I am a firm believer that ABD is a distinct clinical entity that proves challenging to the police and medical personnel. With greater knowledge of the condition, and increased recognition by Emergency clinicians the fatal outcomes may be reduced, but not entirely eliminated. Should anyone have further questions, or request input I am more than happy to assist.


IMG_0053IMG_0052Winner of the President’sMedal from the Royal College of Psychiatrists.

Winner of the Mind Digital Media Award


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