Aeromedical Retrieval of the Acutely Disturbed Patient – 2015

Monitored with ketamine infusion at 80mg/hr

Monitored with ketamine infusion at 80mg/hr, unintubated


Original article by Dr Minh Le Cong
( commenced in 2014 and updated for 2015)

The retrieval of a disturbed patient is one of the most challenging situations for the prehospital and retrieval practitioner. It involves medical, legal and ethical decisions. If aeromedical transport is required, it will likely involve aviation laws and decision making too. Priorities for transport can be difficult to judge when faced with remote patient locations and conflicting other missions. Night time transport , particularly by air can be problematic to negotiate. The disturbed patient poses multiple levels of complexity in retrieval planning, logistics and clinical care. Ultimately the balance must be sought for the needs of the patient but also for the safety of all parties involved in the process.

Medicolegal, aviation and ethical considerations
In most countries, there exist specific laws governing the medical situation whereby a person is suffering from an acute diminished capacity for informed consent, due to either a mental illness, intoxication or physical illness. This often involves the legal process to conduct an involuntary medical assessment and treatment of the person unable to give consent due to their acute incapacity. As transport maybe required for such assessment to be performed, this element is usually written into the appropriate legislative act as well. These acts generally impose time limits upon the involuntary assessment process, pending formal diagnosis and treatment by authorised providers, usually a mental health specialist medical practitioner.
A universal guiding principle of such acts involving involuntary detention and assessment is the use of minimal restraint, physical and chemical, to enable adequate completion of the process. What minimal restraint constitutes is left open for interpretation by health professionals and other agencies involved in the transport and assessment of such patients under the relevant acts. Certainly health professionals from various backgrounds have interpreted the use of minimal restraint principle , differently.

All countries with aviation laws , have legislated that the pilot in charge of the safe operation of an aircraft, is empowered to refuse any passengers, deemed to present a risk to such safe operation. In addition pilots in general are empowered, to request the assistance of other passengers or emergency services, to restrain a disturbed passenger to enable safe conduct of the flight. The principle of minimal restraint is also applied here.

Whilst it is often assumed that the safe operation of an aircraft is paramount, this does not absolve the duty of care and ethical considerations for patient rights and quality care without informed consent. Is the restraint required for managing a disturbed patient on a 2 hour flight different to that required for a 2 hour observation in an emergency department? Ethically there should be no difference. However the limitations of the aeromedical environment are oft used to justify different approaches to restraint. Is this evidence based or simply a product of prejudice, poor understanding and a culture of zero tolerance towards mental health patients? Is there a best practice approach meeting the needs of all?

Decision making and risk assessment for the disturbed patient retrieval
There exists a whole separate discussion on the merits of managing disturbed and agitated patients in remote areas, but let us assume for now , that the decision has been made that an acutely agitated patient requires aeromedical transport to a higher level facility. Let us also assume the patient is under the involuntary section of the relevant mental health act.

Clearly the process of planning for such a retrieval is to undertake a formal risk assessment. There exists no validated risk assessment tools for the aeromedical retrieval setting but several do exist for emergency mental health and criminal prison settings. The elements most useful to identify truly high risk patients, based on expert opinion and extrapolated from psychiatric research are

1. past history of violence
2. acute intoxicated state
3. acute environmental stressor
4. the need for sedation in the preceding 24 hrs
5. history of current or substance abuse, including nicotine.

In the authors experience, the benefit of a formal risk assessment process is in mission planning, well before the retrieval team meets the patient. This allows adequate staffing and planning for restraint measures. Ideally a high risk patient identified during risk assessment will be assigned a retrieval team of at least two providers, with the non technical and technical skills in managing a wide range of agitated behaviour.
The common mistakes at this stage are in not performing a risk assessment or more likely not performing it adequately. The next most common mistake is in ignoring the risk assessment

During handover it is important to reassess the risk based on direct contact and communication with the patient. Many handovers of patients are conducted on the tarmac to allow speed of transport and avoid delays. This is often a mistake and despite causing delays, it is prudent to do a proper handover and risk assessment at the referring facility with referring staff on hand to clarify questions and provide assistance. All identified high risk patients should be performed as a facility handover, despite the temptation to load and go quickly to make it a faster transport.

Part of but essential to any risk assessment of the agitated patient is a proper medical examination and review. The risk assesssment is not just for safety of the retrieval team, it is above all for the safety of the agitated patient . Finding reversible causes of agitation will greatly reduce the need for restraint and allow adherence to principle of minimal restraint. Sedation during transport in the unintubated patient is like any other anaesthetic, and should be performed with adequate assessment of airway, medical fitness and risks of complications like aspiration, airway obstruction etc.

Preparing the disturbed patient for transport
Like all critical retrievals, the key is in stabilisation and preparation for transport. Treating the agitation is incredibly helpful and will often make the difference between using minimal restraint and excessive force. Obvious reversible causes should be sought and addressed.

1. Nicotine withdrawal – this is often neglected but can be readily addressed with early initiation of nicotine replacement therapy, as patches or gum. A medical assessment of likely nicotine addiction will enable this common cause of agitation to be planned for well ahead of transport time. Allowing the patient to smoke is reasonable if that can be supervised safely, up until time of loading onto transport vehicle.
2. Fear of flying – it is underestimated the fear of flying and it may well be unethical to subject a truly phobic patient to this stress. Often this can be managed adequately with approrpaite sedation but simple communication and education goes a long way to help alleviate anxiety
3. Hunger/thirst – this is a tricky one as it is prudent to keep a patient as fasted as possible in the event of need for deep sedation or indeed intubation as part of overall restraint management or in an emergency. However clear fluids are reasonable up until 2 hrs from transport time and the use of lollies may help.
4. Toiletting – a full bladder is very disturbing and efforts to ensure adequate toiletting prior to flight will help reduce agitation related to this.
5. Pain – any acute pain condition will exarcebate underlying agitation from another cause. A balance of adequate analgesia and sedation must be struck by the diligent retrieval provider. Early adequate analgesia plan will assist the transport greatly

Agitated patients, particularly those with chronic substance abuse disorders or are on regular psychiatric medications often require above average levels of acute sedation to help control their distressing symptoms. The key here is to start regular oral sedation early, well before the time for transport. If this is done early enough in sufficient doses , then the need for retrieval sedation is almost eliminated in the authors experience.

Oral benzodiazepines combined with an antipsychotic are sufficient in many cases but need to be given regularly to maintain sufficient plasma levels. Think of how you would treat a patient in acute alcohol withdrawal. They often need oral diazepam 1-2 hrly. Oral sedation when supervised by trained health professionals is exceptionally safe even when given frequently.

The minimum preparations for aeromedical retrieval of a disturbed patient under the involuntary section of the mental health act are
1. IV access x 2
2. Fasted state ideally
3. adequate oral sedation for preceding 12 hrs
4. Use of physical restraints
5. two person retrieval team with skills for procedural sedation and Advanced airway management

Several aeromedical organisations utilise a single retrieval provider ( nurse or paramedic) and a police officer . This is usually for patients assessed as low risk. This is not the author’s preferred approach. The retrieval must provide the same if not greater level of sedation care than that would be occur in hospital. This generally dictates having at least two trained clinicians for procedural sedation. If intubation might be needed to control the airway and afford deep level sedation then at least one of these retrieval team members must be competent in advanced airway management and emergency general anaesthesia.

If all goes well and to plan, then the retrieval team should not need to provide much transport sedation at all. However, there will be some patients who require ongoing sedation during transport and this must be provided in a safe yet efficacious manner.

Retrieval sedation
The goal of retrieval sedation is to provide the agitated patient with a calmer and more relaxed state, yet still remain cooperative enough to obey verbal commands from retrieval staff. A safe sedation level must be maintained albeit at times deeper levels of sedation may be required during more distressing parts of the transport i.e engine startup, take off.
A validated sedation scoring system is a valuable tool in monitoring sedation depth and safety. The one I utilise is the Richmond Agitation Sedation Score. It is important to aim for a target sedation range and have good reason to go deeper or lighter. All procedural sedation is a type of anaesthesia and so meticulous attention to airway assessment, medical fitness for anaesthesia and a rescue plan in event of complications , is mandatory. In an aeromedical retrieval, if sedation complications occur such as apnoea or airway obstruction, then rather than try to recover the patient and then have to resedate, it may be more prudent to proceed to general anaesthesia and advanced airway support for the rest of the journey.
It is far better to have planned for this well before hand and obviate the need to provide emergency anaesthesia in a moving vehicle with only one assistant.

Two common situations are encountered in retrieval of the highly disturbed patient. Firstly, the retrieval team arrives and the patient is still combative and highly disturbed. Traditionally this has usually necessitated emergency rapid sequence induction and intubation to control the behaviour and the risk of harm to all. This is not without significant risk in and of itself so research by the author and colleagues has found that rapid procedural sedation with ketamine has often allowed adequate control and the ability to transport the patient safely without needing invasive airway management. This is now regularly performed using intravenous infusion of ketamine, physical restraints and full monitoring including non invasive capnography. We have done this for up to 4 hour flight retrievals with no significant complications.

The traditional concerns of emergence delirium and worsening of psychosis with ketamine have not been an issue in our clinical experience during aeromedical retrieval. Local psychiatrists have examined transported patients over an extended period of time and have not reported any obvious worsening of their psychotic conditions.

The second most common retrieval situation is the retrieval team arriving to find the patient withdrawn but otherwise cooperative, despite a risk assessment of extreme level . This might be due to recent sedatives taking effect or a natural course of their acute mental illness. In these situations it is often prudent to perform the handover at the facility and transfer the patient over onto the transport stretcher and apply restraints to test their acceptance of the retrieval process. The retrieval provider may choose to hold off on further sedation and observe the behaviour of the patient. What must not be compromised is the application of physical restraints. These are an important safety element to mitigate any unexpected agitated behaviour. It is our experience that on several occasions patients who were assessed as high risk but who appeared totally calm and cooperative during handover , have gone on to become significantly and unexpectedly agitated during flight. One theory is that acute nicotine withdrawal sets in during the course of a long flight. Another theory is that the summative effects of altitude, vibration and noise eventually produces enough stress as to trigger agitation in a patient who is already distressed by mental health symptoms.
Either way, it is not good for a retrieval team to have to physically struggle with a patient inflight. This is why the preflight placement and securing of adequate physical restraints is so important. Many feel embarrassed in applying the restraints securely or feel that to do so is overtly aggressive to the patient. The approach the author takes it to explain these are safety straps and are necessary for the transport to occur.

The goal of retrieval sedation is to maintain a steady level of sedation effect and avoid peaks and troughs that may cause under or over sedation. The superior strategy is an intravenous infusion. Initiating this preflight and waiting five half-lives of the infused sedative to lapse, whilst observing the effect, is a sensible strategy to achieve steady state for the sedation.

When should one just proceed directly to emergency intubation and general anaesthesia? This will always remain a clinical decision with no absolute indications but the following have been found to be a useful indicator of the need for early advanced airway management:
1. Intoxicated state – safe sedation in an intoxicated patient is challenging and can go very wrong, with several reported cases of lethal aspiration and respiratory depression occuring. It is better to err on the side of securing airway in these cases
2. Failed procedural sedation – some patients will fail even ketamine sedation. There is usually no point in persisting if the patient is clearly not improving. It is much safer to proceed to taking over airway and general anaesthesia
3. Complicating medical/surgical condition – some patients have medical conditions that will make effective and safe sedation difficult. Typical example is the patient who has taken an intentional overdose, is agitated and needing higher level ICU care at another location. Procedural sedation may be risky here as it can potentiate any overdose drugs ingested. Early airway control and general anaesthesia will facilitate the rapid but safe transport of such a patient

Physical restraints
Retrieval of the disturbed patient must include the use of approved physical restraints. Even in the intubated patient, there have been occasions of too light sedation, allowing a dramatic self extubation to occur during flight. There are several types in common use, typically ankle and wrist straps , even a body net. There is no perfect system and unless one wants to use police type restraints with body belts and handcuffs, all medical restraints do is to slow the patient down and allow clinical staff time to control the agitated behaviour, genereally by providing some acute sedation.

There are clear rules of safety to follow when physically restraining a patient. The supine position is safest whilst the prone position is the most dangerous for restraint asphyxia. Never allow a patient to struggle against their restraints. There is a clear risk, well documented of sudden death as a result of rapid lactic acidosis when intoxicated patients struggle against restraints. If this starts to occur the safest option during retrieval is to adequately sedate the patient.

Restraints need to be adequately applied and proper training and practice in their application should be mandatory for all staff that may be needed to utilise them for retrieval of the disturbed patient. This includes pilots, nurse and doctors on the retrieval team. The safety of all is paramount and requires a team approach with all members understanding what is needed by each other to ensure safe retrieval .

International perspective

There is in fact no clear consensus internationally let alone within the borders of a nation like Australia as to what constitutes best practice in the retrieval and transport of the acutely disturbed patient. Many nations do not require the aeromedical transport of such patients as distances between health care facilities are short and often a road transport is quickest and most convenient. It is only nations with large distances in between hospitals and communities in remote areas that require such a service of their aeromedical organisations. Places like Canada, Australia and USA have had the most experience in dealing with the aeromedical retrieval of disturbed patients with a mental illness. Even within Australia there exists no national guideline or policy on how to best undertake the transport of those with a mental illness, often necessitating a flight of several hours duration. The US Air Force have been utilising a standard system of assessment and management of agitated military personnel requiring aeromedical transport since WWII. An emphasis on adequate preflight stabilisation, use of physical and chemical restraints and adequate flight escorts, has allowed the USAF to conduct large numbers of aeromedical evacuations of psychiatric casualties from various conflicts right up to modern day military campaigns. It is salient point to note that USAF guidelines specifically limit the maximum level of restraint and exclude the use of intubation and general anaesthesia for their evacuated personnel requiring sedation for acute agitation.

Aviation perspective

The greatest concern unique to the aeromedical setting for disturbed patient retrievals is the risk of disruption to safe operation of the aircraft by an agitated patient. This must be respected by medical and nursing staff and it is fair to say that aviation professionals may adopt a zero tolerance approach to the matter. The fact is the risk of serious disruption is rare but has occurred with notable cases of passengers becoming violent inflight, albeit usually on commercial aircraft travel. The doctor or nurse must work with their aviation colleagues to ensure that a safe air transport will occur and so good communication of all details and planning must be made to all team members. All clinical care decisions must still reside with the treating nurse or doctor and should not be dictated by aviation staff who ultimately have the legal power to veto any passenger boarding of an aircraft in which they are charged with safe operation. The aviation concerns do not override the clinical duty of care to an involuntary patient who cannot provide informed consent. It might seem simple to accede to the requests of a pilot to intubate and anaesthetise a patient for safe transport at night, but this does not absolve a doctor or nurse of their duty of care to safely treat the patient, which may mean not proceeding with a risky intubation and not transporting until more planning and resources can be brought to bear to undertake a safer aeromedical transport.

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