• Case Study #3: Head Injury or CVA?

    by Alan Batt. Last modified: 03/03/14

    ctscan

    Patient & Apparent Chief Complaint

    A 68 year old male presents to ambulance crew through emergency call after falling from his bicycle at an unknown speed.

    History

    Patient was cycling on quiet country road when he fell from his bicycle. He was not wearing a helmet at the time. His friend found him semi-conscious on the road. He was placed sitting in a car that stopped to help where he was still sitting on arrival of ambulance crew.

    Initial Clinical Findings

    • Airway – partially obstructed, large amounts of vomit evident
    • C Spine – suspected (MOI: fall, altered LOC)
    • Breathing – regular
    • Circulation – Pulse present, regular, skin colour pale, cap refill delayed (>2 sec)
    • Disability – LOC before ambulance arrival; patient experiencing periods of lucidity, alternating with responding to voice

    Clinical Impression

    Head injury secondary to fall

    AMPLE History

    • A No known allergies
    • M Currently taking ant-hypertensive medications
    • P History of hypertension, investigated for right sided weakness 2/52 previous to event
    • L Last oral intake lunch earlier that day
    • E Found semi-conscious on road after fall from bike, no evidence of collision with vehicle

    Observations – Prehospital

    • Pulse rate 58bpm
    • Pulse rhythm Regular
    • ECG rate 58
    • ECG rhythm Sinus bradycardia
    • Resp rate 20 per minute, normal, regular
    • Resp quality Equal air entry bilaterally
    • SaO2% 99% on 15lpm via NRB
    • Cap Refill >2secs
    • BP 136/101
    • Pupils Left size 3, reactive. Right unreactive, (damaged in surgery)
    • GCS 15/15 (E4, V5, M6)
    • BGL 7.1mmol/l

    Prehospital care & management

    O2 @15lpm commenced via non-rebreather mask. Cervical collar applied. Patient extricated from vehicle via rapid extrication, as vomiting profusely, unable to manage airway adequately. Secured to longboard, transferred to ambulance. Suction provided as patient’s level of consciousness began to deteriorate, snoring respirations evident.

    En-route, GCS reduced to 3/15, patient unresponsive. OPA inserted, not tolerated. Vomiting profusely, incontinent of urine, decorticate posturing evident. Transported in right lateral position to allow for airway management. On arrival at ED  patient exhibiting decerebrate posturing.

    In-hospital care & management

    Patient triaged as Category 1 (Life-Threatening Condition) with Head Injury, Spinal Injury, Unconscious. Brought directly to Resus room. Aggressive airway management commenced. Patient sedated, paralysed and intubated (RSI). Urinary catheter inserted. Blood tests taken.

    Clinical Findings

    No overt head injury evident. Query cause of fall. Sent for CT Brain. Large hypertensive bleed found on scan. Patient sent to ICU on ventilator. Patient diagnosed with severe hypoxic brain injury secondary to hypertensive CVA. Family and healthcare provider joint decision to turn off ventilatory support 26 hours post-event.

    Identification of all interventions initiated and rationale

    • Oropharyngeal airway – to protect the airway due to decreased level of consciousness
    • Suction – to clear the airway of vomit due to patient’s inability to maintain own airway
    • Pulse oximetry – to monitor oxygen saturation levels in the blood
    • Supplemental oxygen – to re-oxygenate patient
    • Cervical collar and longboard – to provide support and protection to cervical spine due to serious mechanism of injury suggestive of spinal injury
    • 3 Lead ECG – to identify any life-threatening arrhythmias
    • 12 Lead ECG – to identify any life-threatening arrhythmias or ECG changes indicative of myocardial damage (primary cause of fall, secondary to hypoxia etc.)
    • CXR – to identify pneumothorax, pleural effusion etc. that may increase morbidity
    • Blood tests – to identify any electrolyte imbalances etc.
    • Urinary catheter – to monitor urinary output to ensure adequate renal function
    • CT Brain – to identify any cerebral haemorrhage or infarct that may be indicative of primary cause of fall.

    Learning Outcomes

    Rapid Sequence Intubation (RSI)

    Rapid Sequence Induction is the use of a sedative with a paralytic agent to facilitate endotracheal intubation in an aggressive/combative/non-compliant patient who requires airway management (such as in severe head injuries). This is an intervention currently outside the scope of practice for many Paramedics worldwide, unless operating at a Critical Care or Intensive Care Paramedic level.

    There are many studies and articles detailing both the benefits and disadvantages to performing RSI pre-hospital in the hands of Paramedics – non-anaesthetic practitioners have a higher tracheal intubation failure rate during pre-hospital RSI. (Ochs et al., 2003; Wang et al.; 2001; Sloane et al., 2000; Dunford et al., 2003; Fullerton et al., 2011; Bernard et al., 2014).

    Wang et al. (2001) comes to the conclusion that prehospital RSI can be harmful to patients with TBI. Sloane et al. (2000) found no difference in outcomes between prehospital and intrahospital RSI outcomes, with similar success and complication rates. RSI is an approved skill for Paramedics in certain jurisdictions such as San Diego, and 29 of the states in the US have medication assisted intubation protocols for use by Paramedics (Gausche-Hill, 2004)

    Severe traumatic brain injuries are associated with aspiration, bradycardia, hypoxia and further complications. Wang et al. (2001) also pose the question “Should we be intubating prehospital at all?”. This is an area of constant debate in the past few years, and opinions are mixed.

    Restrictions on RSI protocols could include, but are not limited to:

    1. That it be restricted to experienced Paramedics with a minimum qualification period
    2. That it be restricted to Paramedics that complete a required training programme, including a certain number of successful intubations in an operating theatre in addition to their initial training
    3. That these individuals maintain a certain number of intubations and medication-assisted intubations annually
    4. That there be strict protocols on its’ implementation as per clinical guidelines
    5. That is always a secondary fallback device available when undertaking RSI, such as a supraglottic airway device (LMA, Combitube etc.) in case of failed intubation

    The issues that arise with authorising RSI for prehospital use by Paramedics include prolonged scene times, induced bradycardia, raised ICP and oxygen desaturation to name a few. Additional medications would also need to be added to the list of approved medications for many practitioners in order to allow for RSI to be introduced. The implementation of this intervention in any jurisdiction needs to be investigated regarding feasibility, training requirements, syllabus construction, cost implications etc.

    Abnormal Posturing

    Abnormal posturing (pathological posturing) can often be seen in patients with a serious CNS insult/injury such as that associated with a head injury, CVA, CNS infection or other cause. Normally, when a muscle contracts, the muscles on the opposite side of the joint provide some resistance to contraction. Abnormal posturing occurs when damage to the CNS (brain or spinal cord) results in complete or partial lack of opposition to muscle contraction in various muscle groups.

    There are 2 types of posturing: decorticate and decerebrate.

    posture1Decorticate Posturing

    This involves rigidity, flexion of the arms, clenched fists, and extended legs. The arms are bent inward toward the body with the wrists and fingers bent and held on the chest. This type of posturing implies severe damage to the brain.

    Decerebrate Posturing

    This involves rigid extension of the arms and legs, downward pointing of the toes, and backward arching of the head. A severe injury to the brain at the level of the brainstem is the usual cause of decerebrate posture.

    Opisthotonos

    This is a condition of abnormal posturing that involves rigidity and severe arching of the back, with the head thrown backward. If a person with opisthotonos were laid on his or her back, only the back of the head and the heels would touch the supporting surface. This often accompanies decerebrate posturing in severe CNS insult. (Elling et al., 2007)

    A patient may alternate between different postures as their condition worsens/improves. According to Russell and Triola (1995) and Weiner and Goetz (2004) in general, patients with decorticate posturing have a better prognosis than patients who exhibit decerebrate posturing, although decerebrate posturing can be seen with some forms of reversible yet severe encephalopathies.

    Methods to reduce increased ICP associated with endotracheal intubation

    Endotracheal intubation is the definitive method of securing an airway in a patient with a severe head injury. However, endotracheal intubation is linked with a marked raise in ICP for a duration of 3-5 minutes. The exact effect this transient raise in ICP has on primary and secondary brain injury is unknown, however it is widely believed that it has a detrimental effect on secondary brain injury, due to cerebral hypoperfusion.

    The use of IV lidocaine prophylactically prior to intubation (as in RSI) is recommended by Salhi & Stettner (2007) and various other authors. However, there are other authors and studies such as Robinson & Clancy (2001) who indicate that the use of IV lidocaine to mitigate rises in ICP related to intubation should not become accepted practice until further studies are carried out.

    Hyperventilation is another technique that can be used to decrease ICP. However, this should be as a last resort, after all other options have been exhausted – i.e. if death is imminent. Hyperventilation causes hypocapnia, which in turn causes cerebral vasoconstriction and thus decreased cerebral bloodflow. The end result of this is decreased ICP, however at the cost of possibly aggravating secondary brain injury due to hypoxia associated with hypoperfusion (Stocchetti et al., 2005; Smith, 2005)

    Hypoxia is also to be avoided in head injury patients, as a decreased blood oxygen saturation leads to acidosis, which results in vasodilation. Vasodilation results in an increased ICP, further compounding brain injury (Shah & Kelly, 1999)

    As per the Monro-Kellie Doctrine, ICP is directly related to the volume of contents within the cranial vault.

    v.intracranial vault = [v.brain + v.csf + v.blood]

    Therefore, to decrease ICP, blood, CSF or cerebral mass must be decreased. As the volume of CSF and amount of cerebral matter remains static, the alteration in blood flow is the main component that is adjusted (through vasoconstriction and vasodilation) to adjust ICP. (Mokri, 2001)

    The use of cervical collars in patients with severe head injuries – helpful or harmful?

    Any patient with a significant mechanism of injury is treated for suspected spinal injury as per protocol in many jurisdictions. Recent studies have shown however that the application of rigid cervical collars can result in a marked increase in ICP, with increases of up to 12mmHg noted in some studies (Hunt et al, 2001)

    The very nature of rigid cervical collars means they are applied firmly, and thus can impede venous drainage from the cranial vault. (Craig & Nielsen, 1991). They can also act as a nociceptive stimulus, further increasing ICP.

    There are limited options for replacing rigid cervical collars in the prehospital setting. The risk of spinal injury with severe head injuries is too great to recommend non-application of rigid cervical collars. As per Hunt et al. (2001) the recommendation is to x-ray and examine the patient’s cervical spine as soon as practicable on admission to the ED, and remove the rigid collar if possible at the earliest opportunity. If this is not possible, then replacement with a soft collar or other forms of spinal immobilisation is recommended.

    Primary v Secondary Brain Injury

    Primary Brain Injury

    This results from what happens to the brain at the time of initial injury.

    Secondary Brain Injury

    This results from the biological, physiological and biochemical effects that occur as a result of primary injury. Examples of this include hypoxia, necrosis, cerebral oedema, inflammation, and ischaemia. (AAOS, 2005)

    Helmet efficiency in reducing incidence of head injuries sustained whilst cycling

    According to Henderson (1995) “Wearing a helmet substantially reduces the risk of head injury to a cyclist in a crash. This has been shown by a raft of strong evidence generated by epidemiological and biomechanical research, and cited in the present report.”

    In a study carried out by Maimaris et al. (1992) a head injury was sustained by four out of 114 (4 per cent) of helmet wearers, compared with 100 out of 928 (11 per cent) of non-helmet wearers. The risk reduction in wearing a helmet was concluded to by over 60%. They also found that all the patients who had sustained traumatic brain injuries, and two fatalities which resulted from head injuries had not been wearing helmets at time of injury.

    Whilst not a legal requirement, several studies including those cited above have shown that wearing a helmet whilst cycling significantly reduces the incidence of head injuries sustained in the event of a collision or fall.

    References (non-PubMed)

    AAOS (2005) Emergency Care and Transportation of the Sick and Injured 9th Edition. Massachusetts: Jones & Bartlett

    Elling B, Caroline N, Smith M (2007) Nancy Caroline’s Emergency Care in the Streets, 6th Edition (UK Edition). London: LWW

    Gausche-Hill, M (2004) Pediatric Airway Management for the Prehospital Professional. Massachusetts: Jones & Bartlett

    Henderson M (1995) The Effectiveness of Bicycle Helmets: A Review. Summary for the Motor Accidents Authority of New South Wales, Australia. Bicycle Helmet Safety Institute.

    JRCALC (2006) UK Ambulance Service Clinical Practice Guidelines 2006. JRCALC

    Shah S, Kelly K (1999) Emergency Neurology. Cambridge: Cambridge University Press

    Smith S (2005) ICP & Head Trauma. Presentation to US Army Medical Corps Staff, June 2005. Unpublished

    References

     
    1.

    Fullerton JN1, Roberts KJ, Wyse M. Should non-anaesthetists perform pre-hospital rapid sequence induction? an observational study. Emerg Med J. 2011 May;28(5):428-31. PMID: 20660897.

     
    2.

    Bernard SA1, Smith K, Porter R, Jones C, Gailey A, Cresswell B, Cudini D, Hill S, Moore B, St Clair T. Paramedic rapid sequence intubation in patients with non-traumatic coma. Emerg Med J. 2014 Jan 28. PMID: 24473409.

     
    3.

    Ochs M1, Davis D, Hoyt D, Bailey D, Marshall L, Rosen P. Paramedic-performed rapid sequence intubation of patients with severe head injuries. Ann Emerg Med. 2002 Aug;40(2):159-67. PMID: 12140494.

     
    4.

    Craig GR1, Nielsen MS. Rigid cervical collars and intracranial pressure. Intensive Care Med. 1991;17(8):504-5. PMID: 1797898.

     
    5.

    Dunford JV1, Davis DP, Ochs M, Doney M, Hoyt DB. Incidence of transient hypoxia and pulse rate reactivity during paramedic rapid sequence intubation. Ann Emerg Med. 2003 Dec;42(6):721-8. PMID: 14634593.

     
    6.

    Hunt K1, Hallworth S, Smith M. The effects of rigid collar placement on intracranial and cerebral perfusion pressures. Anaesthesia. 2001 Jun;56(6):511-3. PMID: 11412154.

     
    7.

    Maimaris C1, Summers CL, Browning C, Palmer CR. Injury patterns in cyclists attending an accident and emergency department: a comparison of helmet wearers and non-wearers. BMJ. 1994 Jun 11;308(6943):1537-40. PMID: 8019309.

     
    8.

    Mokri B. The Monro-Kellie hypothesis: applications in CSF volume depletion. Neurology. 2001 Jun 26;56(12):1746-8. PMID: 11425944.

     
    9.

    Salhi B1, Stettner E. In defense of the use of lidocaine in rapid sequence intubation. Ann Emerg Med. 2007 Jan;49(1):84-6. PMID: 17197290.

     
    10.

    Sloane C1, Vilke GM, Chan TC, Hayden SR, Hoyt DB, Rosen P. Rapid sequence intubation in the field versus hospital in trauma patients. J Emerg Med. 2000 Oct;19(3):259-64. PMID: 11033272.

     
    11.

    Stocchetti N1, Maas AI, Chieregato A, van der Plas AA. Hyperventilation in head injury: a review. Chest. 2005 May;127(5):1812-27. PMID: 15888864.

     
    12.

    Wang HE1, Yealy DM. Out-of-hospital endotracheal intubation: where are we? Ann Emerg Med. 2006 Jun;47(6):532-41. PMID: 16713780.

    The following two tabs change content below.
    Alan Batt

    Alan Batt

    Paramedic, educator, researcher
    Alan is a critical care paramedic, paramedic educator and prehospital researcher, currently working around the world as an educator and researcher. He has previously worked and studied across Europe, North America and the Middle East. He holds a Graduate Certificate in Intensive Care Paramedic Studies, and an MSc in Critical Care. His main interests are in care of the elderly, end-of-life care, patient safety, professionalism (including role and identity), and paramedic education.

    Tags: , , , ,

    Leave a Reply