A 58 year old man is brought in by ambulance moribund with barely palpable pulse and a sinus tachycardia.

(a) Outline you management in the first fifteen minutes. 

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College Answer

A case of near electromechanical dissociation  in a 58 year old man. This could be caused by hypovolaemic shock. anaphylaxis or cardiogenic shock etc. Therefore the candidate should have started with a comprehensive approach and be directed to specific problems.

(a) An outline is requested but it should contain some rationale. eg:

•  A/B if the patient is breathing and talking apply a 100% oxygen mask. If not. bag with face mask and high·flow (h.   LOC may improve rapidly with BP restoration, but if not, intubation and ventilation will be necessary.

•  Quickly assess the patient's volume status (JVP visible?, veins engorged). Establish best venous access  possible (peripheral IV. external jugular, femoral). If the patient appears hypovolaemic. commence bolus of fluid. Continue fluid boluses until filling  pressures appear adequate as judged by rise in NP, CVP (or PAOP) or occurrence of worsening respiratory distress(? pulmonary.oedema).

•  If the patient is not hypovolaemic on arrival or remains hypotensive despite achieving adequate filling pressures give 1mg increments of araminc and commence an inoconstrictor infusion.

•     As soon as possible insert an intra·arterial cannula. It is possible that the central BP is adequate.

Meanwhile, a primary survey should be undertaken to determine the cause and a detailed history sought. Life-threatening injuries arc excluded. The patient is quickly examined from head to foot for signs of anaphylaxis (erythema, wheals etc), cardiac failure or tamponade (venous congestion, raised JVP). Tension pneumothorax or sepsis (hot. flushed, local signs) etc.

Investigations and initial treatments should be guided by the history and signs eg. intercostal catheter.pericardio--centesis.·

Discussion

This 58 year old gentleman is about to have a PEA arrest. Perhaps "moribund" is probably not a very precise medical term, but according to the all-knowing oracle of Wikipedia it refers to a "literal or figurative state of near death", which is appropriate to describe a man with a barely palpable rapid pulse.

However difficult to palpate, the pulse is still palpable.

The patient has not yet arrested.

One's priorities, then, are to assess this patient, rapidly determine the cause of his hemodynamic instability, and reverse the immediately reversible factors.

Perhaps he has not arrested yet. Still, the 4 Hs and 4Ts apply:

  • Hypoxia
  • Hypovolemia
  • Hyper/hypokalemia
  • Hyper/hypothermia
  • Tension pneumothorax
  • Tamponade (i.e. cardiac tamponade)
  • Toxins (eg. anaphylactic reaction or intoxication)
  • Thrombus (eg. a PE or MI)

Thus, a stepwise approach to this problem would be something resembling the following:

1) Ensure personal safety

2) Perform a basic peri-arrest primary survey

  • Immediate assessment to diagnose cardiac arrest
    • Are they awake?
    • If they appear unconscious, shake them and ask "Are you alright?"
    • If they are unresponsive, look listen and feel for respiratory effort.
    • If the patient is unconscious, unresponsive, and is not breathing, call for help and start CPR.
      Otherwise, move on with the structured approach to prevent cardiac arrest
  • Airway:
    • Assess patency: best done by interrogating the patient. If he provides coherent answers to your questions, his ABCs are unlikely to be desperately compromised. If he does not, one should secure his airway - initially usig unsophisticated techniques (jaw thrush, chin lift), progressing through airway adjuncts to intubation as needed.
    • Look for presence of vomit or foreign body
    • Prepare to progress to intubation
  • Breathing
    • Observe respiratory rate
    • maintain oxygenationintially with high flow oxygen via tight-fitting reservoir mask. A high flow nonrebreather mask not only delivers around 75% FiO2, it also allows one to assess respiratory function by observing the expiratory fogging of the clear plastic, and one can hook up an end-tidal capnometer to it to detect expired CO2.
    • progress to bag-mask ventilation if respiratory arrest occurs
    • Auscultate the chest, percuss it, palpate for surgical emphysema
    • Investigate with ABG and urgent CXR
    • Specific differentials to consider before moving on with the survey:
      • Massive PE (distended neck veins, cyanosis, tachycardia and hypotension)
      • Acute severe asthma (silent hyperexpanded chest, the hint of wheeze)
      • Tension pneumothorax (unequal air entry, deviated trachea, hyper-resonant chest)
      • Massive haemothorax or effusion (unequal air entry, deviated trachea, dull percussion note over the hemithorax)
      • Pulmonary oedema (pink frothy sputum, coarse gurling creps)
  • Circulation
    • Ensure large-bore IV access
    • Measure the blood pressure non-invasively and attach ECG leads for monitoring
    • administer IV fluids as bolus
    • administer readily available vasopressors, eg. metaraminol in order to maintain cerebral perfusion
    • assess for sources of bleeding
    • ABG or FBC to assess Hb, and need for transfusion
    • rapid bedside TTE to assess cardiac chamber volume and contractility
    • Specific differentials to consider before moving on with the survey:
      • Extremes of hypovolemia (collapsed veins, empty chambers, slow capillary refill, dry mucosae, cool extremities, weak rapid pulse)
      • Haemorrhagic shock ( exactly as above but also deathly pallor)
      • Cardiac tamponade (distended neck veins, muffled heart sounds, electrical alternans on ECG)
      • Peri-arrest arrhythmia (eg. VT or SVT)
      • Severe sepsis (mottled skin, fever, hyperdynamic circulation with hypotension)
    • A fluid bolus would be an appropriate reaction in any case. A hand-operated pump giving set with a litre of crystalloid should be set up. Ideally, one should prepare for invasive arterial blood pressure monitoring.
  • Disability/neurology
    • Assess for signs of intracranial catastrophe by performing a brief neurological examination, including pupils and muscle tone/reflexes
    • Test BSL: ensure normoglycaemia
    • Specific differentials to consider before moving on with the survey:
      • Intracranial catastrophe (pupils, focal signs)
      • Seizure (increased tone, exaggerated reflexes, gaze deviation, clonus)
      • Extreme hypoglycaemia
      • Hyperglycaemic coma
      • Extremes of electrolyte derangement (eg. a sodium of 90 or 190)
      • Hepatic encephalopathy
  • Exposure/examination
    • Assess for sources of bleeding
    • Examine for features of anaphylaxis
    • Check temperature; ensure normothermia

References

References

ARC Guideline 11.2: Protocols for Advanced Life Support

 

Additionally, the ARC ALS2 manual contains several chapters dealing with pre-arrest scenarios such as this one.