Objectives

This guideline is designed to support clinicians within their deployed scope of practice provide general anaesthesia. It aims to provide a safe and reasonable approach, recognising that clinical teams will provide tailored care depending their experience, training, operational constraints and the presenting patient. Multiple activities are likely to be performed by the anaesthetic team, these areas have their own guidelines and for the sake of brevity have been de-emphasised here.

Scope

What preparation should be done prior to casualty arrival?

What equipment might be needed for an RSI in different locations?

What drugs might be used during an RSI in different situations?

What are the considerations for the anaesthetist during damage control surgery?

What different communication tools can be used before and during damage control resuscitation/surgery?

What different strategies can be used for specific clinical problems?

Audience

Anaesthetists

Peri-operative practitioners

Emergency medicine physicians

Emergency department nurses

Pre-hospital practitioners

Initial Assessment & Management

Before the casualty arrives

• Number, type and severity of casualties?
• Airway at risk or already secured?
• Likely to need massive transfusion?
• Ongoing or concurrent - clinical and operational? 

• Consider likely casualty flow (within and beyond the facility)
• Consider potential courses of action and brief medical teams 
• Determine need to split team between casualties / clinical areas 
• Remember - temperature / acidosis / calcium / coagulopathy 

• Airway equipment, oxygen, suction, ventilator
• Anaesthetic drugs (consider pre-made "wet packs")
• Prioritise large bore venous access - consider invasive lines
• Environmental considerations - patient warming and pressure care  

Damage control resuscitation - anaesthetic considerationsDamage control resuscitation requires concurrent and coordinated activity from the whole team. This process will likely be lead by the emergency physician initially. Exact roles will be determined by clinical priorities and team composition. Coordination with the clinical director and facility OC is essential to maintain situational awareness for appropriate planning. 

Catastrophic Haemorrhage

Identify (including early exposure and roll) and stop the bleed. If external control of ongoing catastrophic bleeding impossible, all efforts should be directed at immediate surgical control of bleeding. This may require induction of anaesthesia in an unstable patient - adjust drug doses, ventilation and fluids accordingly. Consideration should be given as to the appropriate location for induction of anaesthesia.

Airway

See airway guidelines. Oxygenation is the priority at all times. Asses airway and placement of adjuncts, capnography is advised when airway adjuncts are placed and mandated following tracheal intubation. Take a view on likely course and potential for deterioration given location and onward care. Basic airway manoeuvres (including postural changes), devices (including a pillow) and suction may temporise threatened airways. An obstructed or unsafe airway maybe an indication for urgent RSI.

Breathing

Administer high flow oxygen in the critically ill patient, in everyone else titrate (94-98%). Multi-modal analgesia will assist with chest drain insertion and may improve ventilation. Respiratory distress may be an indication for RSI. In severe hypovolaemic shock, aim to minimise intra-thoracic pressure during positive pressure ventilation. 

Circulation

Critical / emergency care is largely impossible without IV / IO access, the anaesthetist is well placed to assist in its placement. Prioritise large bore venous access either peripheral or central, consider use of ultrasound to assist. Aim to administer a balanced transfusion if ongoing haemorrhage. Anticipate coagulopathy - address low temperature, low calcium and acidosis. Aim for haemostatic resuscitation, try to avoid shock, consider fresh whole blood and use of adjuncts including TXA / fibrinogen. Be guided by primarily by physiological parameters in the hyper acute phase. Point of care testing, including blood gas and coagulation assays are informative but take time to process, as a result they may delay active treatment and will often be behind the curve. 

Disability and distress 

See analgesia and sedation guidelines. RSI may be indicated if GCS is reduced. If induction of anaesthesia has been performed maintain anaesthesia usually with an IV agent and ideally via a pump. Ready the patient for onward transfer.

Environment / everything else

Expose the patient and consider the need for further examination, either to complete initial survey or to review following interventions to track progression. Maintain dignity, hygiene and aim for normothermia. Review investigations. Complete documentation and ensure accurate prescriptions. 

The command huddle 

Periodically a pause to share findings, decision-making and predicted trajectory is important. The commonly termed a "command huddle" allows the clinicians responsible for care to maintain situational awareness and maintain the tempo of care. In smaller teams it is often appropriate for all members to be included in these reviews. 

Advanced Assessment & Management

Rapid Sequence Induction (RSI)

It is likely that deployed general anaesthesia will be be required for unscheduled or emergency care. Within the wider clinical team, "RSI" is synonymous with emergency anaesthesia, an intervention undertaken to provide critical care or facilitate surgery. Clinicians should remember the considerable additional demands on the operational patient pathway demanded by the anaesthetised patient and should explore alternatives wherever practicable (procedural sedation / regional anaesthesia / delayed treatment etc).

While the components of an RSI have changed over the years the clinical objectives have not. Clinicians still aim to induce anaesthesia and secure the airway whilst reducing the risk of pulmonary aspiration. Consideration however must also be given to the other potential risks including but not limited to: difficult airway, cervical spine injury, hypoxia, hypercapnia and cardiovascular compromise.

The approach to deployed anaesthesia should be pragmatic and tailored to the patient and situation. Deployed anaesthesia, even for routine cases is a high consequence, low frequency intervention. The anaesthetic team should seek to anticipate, communicate and mitigate concerns. The safest course of action is likely to be that which is most familiar to the clinical team present.

Indications

Indications for RSI in the resus bay:

• Compromised airway eg facial trauma
• Inadequate ventilation eg pneumonia
• Low GCS or agitation eg head injury
• Humanitarian eg uncontrollable pain
• Anticipated deterioration - eg facial burn

Indications for RSI on the operating table:

• Anticipated high aspiration risk eg emergency surgery

Equipment and Team

Equipment should include:

• BVM or Mapleson C (Water's) with appropriate mask 
• Yankauer suction (consider NGT / drain) 
• 2 sizes of working laryngoscope (including VL)
• Appropriately sized ETT (+ 1 size below) and lubricant 
• Bougie (consider 1st line)
• End-tidal CO₂ (ideally waveform) 
• Catheter mount and HMEF
• Syringe and tube tie / tape
• Pillow or positioning aid
• Difficult airway - (OPA / NPA / SGA / X-blade and stylet / bronchoscope and Aintree)
• Can't oxygenate - No 10 scalpel / 6mm ETT

Team should include (+potential actions):

• Anaesthetist - airway lead 
• Experienced anaesthetic assistant
• 2nd clinician to give drugs and monitor cardiovascular changes
• Team leader made aware prior to RSI and present to coordinate emergency actions eg thoracostomy in case of tension pneumothorax, blood transfusion in case of CVS compromise

Induction drugs

In major trauma these drugs are routinely used. Discussion of pharmacokinetic / pharmacodynamic discussion is beyond the scope of this guideline.  

Preferred agents

• Fentanyl 1-2μg/kg at induction. Short acting analgesic, may obtund hypertension of laryngoscopy. Consider higher doses in isolated head injuries. Caution in hypovolaemia, consider omitting or lowering the does.
• Ketamine 1-2mg/kg. More cardio stable than propofol. Analgesic and sedative properties depending on dose. Likely to precipitate a tachycardia.
• Rocuronium 1mg/kg. Preferred paralysing agent. Intubating conditions at one minute, may be slower if low cardiac output. Painful on injection. Stable at STP for 90 days. 

Alternatives

• Suxamethonium 1.5 mg/kg (caution in hyperkalaemia, spinal cord injury > 10 days, burns >24 hrs)
• Midazolam 0.02-0.05 mg/kg at induction
• Propofol 2 mg/kg or using TCI algorithm, caution in hypotension

Points to consider:

Hypovolaemia

In order to control haemorrhage surgery and therefore anaesthesia may be required prior to optimisation. Shocked patients are demonstrate a greater neurological (relatively conserved cerebral blood flow) and cardiovascular (low protein binding following resuscitation, often under-filled, dependent on sympathetic drive) sensitivity to anaesthetic agents; consider dose reductions. Induction agents with a high therapeutic index are preferred to reduce risks of awareness and haemodynamic compromise. Following induction, positive pressure ventilation will likely reduce cardiac filling in hypovolaemia and tamponade, and may precipitate tension pneumothorax.

• Consider fentanyl or ketamine to control agitation (DSI) and facilitate optimisation.
• Where practical, correct hypovolaemia prior to RSI; if impractical ensure ongoing volume resuscitation 
• Consider reduced drug dosing including omission of opiates.
• Allow for delayed onset time (reduced cardiac output)
• Reduce tidal volume and PEEP (to increase cardiac filling). 
• Aim for radial pulse if uncontrolled bleeding, aim for normal BP once surgical control
• Treat hypovolaemia with volume and treat vasoplegia with pressors

Patient positioning and ramping

Patient positioning is challenging when care is provided on a stretcher. Civilian style trollies are likely a better option if available to optimise positioning for airway management and oxygenation. The operating table allows for a degree of tilt that may facilitate pre-oxygenation or postural drainage. Additional equipment including blankets and pillows may be used to provide an pragmatic solution. Elevating stretcher back rests are available but are not easily re-positioned. Positioning for airway trauma is anticipated to be difficult when patients may prefer to be sitting prior to induction of anaesthesia, the use of additional personal to offer physical support or induction on the floor have both been described.  

C-Spine Precautions

Recent (2024) UK guidance from the Association of Anaesthetists recommends that in cases of potential cervical spine injury; attempts should be made to minimise neck movement during pre-oxygenation and facemask ventilation. If a simple manoeuvre is required to maintain an airway a jaw thrust is advised. Videolaryngoscopy is recommended and clinicians should be competent in its use. An adjunct (stylet or bougie) should be considered  when performing tracheal intubation. Cervical collars should be removed or loosened during laryngoscopy. A pragmatic "all-risks" approach, to mitigating against unnecessary cervical spine movement is recommended. 

Cricoid pressure

Application of cricoid pressure has been demonstrated to hamper laryngoscopy and increase cervical spine movement. However the most recent (2015) DAS RSI guideline still recommend its application, ie 10 N (1 kg) when the patient is awake, increasing to 30 N (3 kg) upon loss of consciousness, to be removed only if active vomiting occurs or to improve oxygenation and intubation. PUMA currently include cricoid as a optional component of RSI. The 2025 pre-hospital guidelines from the Association of Anaesthetists (UK) are equivocal but point to a poor evidence base of efficacy, risk of harm and absence from European guidelines. A pragmatic "all-risks" approach, to mitigating against aspiration of gastric contents is recommended.   

Pre-oxygenation

While pre-oxygenation is possible to achieve using a ventilator, most clinicians would advocate using a separate method of oxygen delivery to facilitate de-nitrogenation; either a "trauma" mask (with reservoir, 15 l/pm), a Mapleson C Circuit (Water's) or a BVM. This approach is likely to be more in keeping with regular practice, is simpler and less likely to result in error or delay.

VL or DL 

In UK civilian practice VLS is increasingly becoming the fist line device for intubation. The deploying anaesthetist must be familiar with the devices available on in their facility. In cases of anticipated difficulty or airway trauma the VLS may allow the wider team to visualise the airway. Use of an adjunct (eg stylet) is recommended, especially when difficulty is anticipated or when using a hyper angulated blade. 

TIVA or Volatile

Total Intra Venous Anaesthesia is growing in popularity in UK practice. There are several features of TIVA that make it appealing to deployed anaesthesia - reduced equipment, uninterrupted induction, maintenance of anaesthesia and onward sedation and clinical familiarity. If using TIVA, clinicians should consider the guidance from the Association of Anaesthetists that states processed EEG should be used when TIVA is administered together with a neuromuscular blocker. During emergency surgery for patients requiring volume resuscitation compartment model predictions are likely to be unreliable.

DMS pumps models include Marsh, Schneider (Propofol) and Minto (Remifentanil). Other protocols have been described for use in the deployed environment but are clearly more limited in their evidence base. Continuous infusion of Ketamine for sedation following induction of anaesthesia is well described in prehospital care (military and civilian). A recent scoping review "found a lack of high-quality well-designed studies investigating the use of continuous ketamine sedation on ICU. The available data suggests this intervention is safe and well tolerated, however this is of very low certainty given the poor quality of evidence."

Inhalational induction

Sevoflurane is the ideal volatile agent for inhalational induction. In the deployed environment this technique is usually likely going to be used for uncooperative or anxious child or those with difficult venous access. The major hazards associated with inhalational induction include the uncooperative child, loss of the airway and laryngospasm. A full stomach, low cardiac output state and a compromised airway are relative contraindications. Sevoflourane may either be incrementally increased or for faster induction the induction setting on the  Diamedica Draw-over Vaporiser (DDV2) will deliver in excess of 7-10% (at 20-30 deg C internal temperature). It is common practice to maintain a high inspired volatile concentration until i.v. access is gained, and the return to baseline heart and respiratory rate - useful indicators of adequate depth of anaesthesia whereby insertion of airway adjuncts or cannulation should not provoke laryngospasm. Full anaesthetic monitoring should be applied once the child is anaesthetised.

Checklists

Checklists are used frequently by anaesthetists to improve safety. Checklists help to reduce error, improve consistency and maintain safe systems of work. Widely adopted relevant examples include: equipment checklists published by the Association of Anaesthetists, RSI checklists published by the RCOA, Faculty of Intensive Care and the Surgical Safety Checklist instituted by the WHO. Checklists currently used in deployed perioperative care include the WHO surgical safety check list (full or SNAP) and the sit-rep, encompassing the STACK (Systolic, Temperature, Acidosis, Clotting, Kit). The MERT prehospital anaesthesia SOP includes a pre-RSI checklist. Consideration should be given to the local adoption of bespoke checklists, especially for low frequency high impact clinical interventions.

In the Operating Room

Positioning on Arrival in the Operating Room

Crucifix - The default patient position is Supine with both arms abducted on boards. Consider potential pressure areas (including occiput) and mitigate accordingly. Protect the eyes.

Apply forced air warmer/under warmer, and commence warming ASAP. Consider invasive temperature monitoring to guide warming. 

Don't attempt an arterial line until a strong radial pulse is palpable. Consider urinary catheterisation early. If not already inserted consider CVC for ongoing care.

Handover from the Trauma Team Leader

Handover begins when the patient is properly positioned and safely established on the ventilator / anaesthetic and full monitoring has been applied. Information should include:

• Team introduction if any new members.
• Introduction to patient (ATMIST may be repeated) 
• Summary of findings 
• Treatments given so far
• Transfusion running totals
• Outstanding issues / tasks / medications
• Provisional surgical plan
• Post op plan

Maintenance of Anaesthesia

During hypovolaemic shock, titrate fentanyl and volatile / TCI anaesthetic agents carefully. The priority is haemodynamic resuscitation and survival. 

When bleeding is controlled, carefully titrate in further analgesia (e.g. consider fentanyl up to 15μg/kg) to reduce sympathetic tone, prevent excessive vasoconstriction and permit further volume resuscitation with blood products.

Consider how multimodal analgesia (including regional anaesthesia) may be be implemented to improve comfort, reduce stress and aid onward transfer.

Haemostatic Resuscitation

Prior to surgical control blood transfusion will likely be balanced ie 1:1 (RBC:FFP). Maintain circulating volume with blood products as per the UK Military Massive Transfusion Protocol. Depending on staffing it may be appropriate to devolve anaesthetic roles roles, separating airway interventions / anaesthesia from blood administration / resuscitation. After surgical control has been achieved and there is a degree of physiological stability a single anaesthetist may perform all these roles. During damage control resuscitation beware over-transfusion and hyperkalaemia. As resuscitation continues it is appropriate to Move from a balanced to a tailored transfusion, guided by physiology and lab tests, including blood gas analysis and viscoelastic testing. Be wary of: hyperkalaemia, hypocalcaemia, hypothermia, acidosis and evolving coagulopathy.

Non Technical Skills - Communication and Teamworking

Leadership, followership, teamwork, and situational awareness and communication amongst the team are all vital to ensure safe care.

Maintain effective 2-way communication with Surgery, Radiology, Critical Care and the Deployed Medical Director (if present).

The WHO CHECKLIST (or abridged DCS snap brief should be used before every case, an aide memoir can be found on the theatre documentation. 

A sit rep including time check, STACK (Systolic Temperature, Clotting and Kit), and surgical plan can be considered every 10-30 minutes, after 2+2 blood transfusion or whenever deemed appropriate. These short re-caps help to maintain whole team situational awareness and assist with dynamic decision making. Surgical teams are likely to be focused while operating; plans for onward transfer, time constraints and resource limitations need to be communicated in a considerate fashion. Clinical concerns should be raised early and especially if regarding a patients physiological status is deteriorating.

Encourage and facilitate passage of key information from  surgeons, especially:

• Release or application of tourniquets, vascular clamps or endovascular occlusive
• Difficult surgical control of haemorrhage
• Surgical evidence of coagulopathy
• Changes in surgical findings or plan

Preparing for Post-operative Care

• Agree next destination (e.g. critical care, aeromed or CT [where available])
• Ensure effective post-operative analgesia, including systemic analgesics and regional anaesthesia
• Handover to the receiving team

Prolonged Casualty Care

See critical care 

Paediatric Considerations

The Association of Paediatric Anaesthetists provides a comprehensive learning resource: Paediatric Anaesthesia for Beginners online which may serve a useful aide memoir.

In the context of deployed paediatric anaesthesia, care for the very small, chronically ill or complex patient is unlikely to be encountered. Most paediatric patients that have been cared for by the DMS are otherwise well children who have suffered injury. Refer to the paediatric section of CGOs for general guidance. The published age per age section should be used instead of relying on drug calculations. Age per page calculations are largely based on western children and use ideal body weights. If age is unknown or there is a disparity between a patients age and predicted weight defer to the page representing actual weight rather than age (anticipating that it is most likely for patients to be under rather than over predicted weights). Double check unfamiliar doses and consider drawing up required doses into smaller syringes rather than titrating from larger.

Premedication:

Oral midazolam 0.5 mg/kg (up to 10mg) may be helpful when managing the anxious child.  

Short procedures may be performed using only an induction dose of ketamine (2 mg/kg)

Avoid propofol for maintenance of anaesthesia unless no other option exists.

Mapleson F Breathing system

Also known as a Jackson-Rees modification to the Ayre’s T-piece is a low resistance and low dead space system. It can be used for spontaneous, assisted and controlled ventilation in all ages although is inefficient >20kg. Flows should be 3 x minute volume (4 l/min minimum flow). PEEP / CPAP is provided by partially occluding end of the bag. Scavenging is inefficient. 

Notes on neonates and infants

• More sensitive to anaesthetic drugs and less protein binding - lower doses required per kg.
• More prone to desaturation - lower FRC
• More prone to apnoea and bradycardia - age related, worse if hypoxic, hypercarbic, acidotic
• More prone to hypoglycaemia and hypothermia - check temperature and blood sugar regularly.
• Small airways - consider a roll under the shoulder and remember neutral positioning. 

Thermoregulation 

• Children are prone to hypothermia
• Thermoregulation is a significant metabolic stressor
• Monitor temperature frequently (ideal constantly)
• Maintain normothermia aggressively
• Use warm fluids
• Keep covered where possible 
• Use multimodal warming wherever possible. 

 Endobronchial intubation 

Tracheal tube size should be based on the age per page calculations or estimates from the diameter of the child’s nostril or little finger. A term infant will usually require a 3mm micro cuff tube, alternatively; internal diameter for an uncuffed tube = (age / 4) + 4. Reduce the sized by 0.5mm for micro cuffed tubes. Expected tube length at the lips (age/2 + 12).

To avoid subglottic damage ensure the tube passes easily.

Beware endobronchial intubation, especially after movement or postural change, listen carefully in both axilla.

Fix ETT securely, the trouser leg tape method is used to good effect.

Anticipated Difficult Airway

Thankfully these are uncommon. Remember good communication and utilisation of the whole team. The step wise principles are similar to those in adult practice. CICV – options will depend on surgical expertise, it is unlikely that those present will be familiar with emergency paediatric tracheostomy.

Needle cricothyroidotomy is the preferred first option. (Extend the neck using a shoulder roll, stabilise larynx with non-dominant hand, access the cric membrane with 14 or 16G cannula, aim in a (cordad) direction, confirm location by aspirating air. Connect to either an adjustable pressure limiting device or a 4 Bar O2 source with flow meter (set l/m to child’s age via a Y connector. 1:4 (inspiration : expiration). Cautiously titrate pressure to achieve chest raise, maintain upper airway to aid expiration (eg with SGA).

Surgical cricothyrotomy is suggested if needle cricothyroidotomy fails

Unanticipated Difficult Airway

Common peri-operative critical events in children

• Desaturation - due to a combination of increased work of breathing, small FRC (low intrapulmonary O2 reserve), higher basal metabolic rate and diaphragm dependence. Other causes include: - endobronchial intubation, reduced diaphragmatic compliance from stomach inflation, etc
• Laryngospasm – due to high parasympathetic tone, most likely during light anaesthesia or vagally stimulating procedures e.g. laryngoscopy or extubation
• Bradycardia – due to high parasympathetic tone, most likely during vagally stimulating procedures e.g. laryngoscopy, extubation and squint surgery