garbage truck

Popliteal Artery Injury from Blunt Trauma: A Trauma Case

Author: Stephen Alerhand MD (@SAlerhand)
(Resident Physician, Icahn School of Medicine at Mount Sinai) // Edited by: Alex Koyfman MD (@EMHighAK)

garbage truckEMS notification

“19 y/o M found sitting on curb after being struck by garbage truck. + LOC. Aox3, with obvious deformity to right lower extremity.”

Primary Survey

HR 112            RR 25                        BP 108/54                        100% O2 sat RA

A: screaming in pain, aox3, waxing/waning comprehension
B: equal breath sounds b/l
C: moderately swollen R thigh w/ anterior ecchymoses, cold and pale distal extremity w/o palpable pulses, RLE ttp throughout
D: unable to range RLE

thigh ecchymosis(similar ecchymoses/swelling here to *left* thigh)

Secondary Survey

NCAT
PERRL, TM’s clear
Wearing C-collar, no ttp
Symmetric chest rise, CTAB, no rib step-offs/ttp
Soft, non-tender abdomen
Pelvis stable
RLE as noted previously
Grossly normal spine w/o step-offs or ttp
R inguinal fold lac, perineal lac

Initial Interventions Performed (listed here, then each explained in detail)
  • 3 peripheral IV lines
  • Pelvic binder with bed sheet
  • Tourniquet
  • Massive Transfusion Protocol
  • Tranexamic Acid (TXA)
  • Perineal laceration packed with gauze
  • Endotracheal intubation
Binding the Pelvis

pelvic binding 1pelvic binding 2

  • It was suspected that there could be a pelvic fracture. The pelvis was bound using a bedsheet and large clamps.
  • Goals: prevent reinjury from pelvic motion, decrease pelvic volume, tamponade bleeding pelvic vessels, decrease pain
  • Bed sheet centered on greater trochanters for greatest mechanical stability of the pelvic ring. Tape thighs or feet together. Not too low (foley goes there, or groin access for angio-embolization) or too high (laparotomy).

Tourniquet for Hemorrhage Controltourniquet

  • Compressing the thigh compartment could facilitate clot formation. Could have been done using bed sheets as well.
  • EAST Level 3: In hemorrhage, where manual compression unsuccessful, may use tourniquet for temporary adjunct until definitive repair.
  • Current ATLS:
    • Attempt direct pressure and pressure dressings to control hemorrhage. Only then consider tourniquet.
    • Tourniquet time should be limited. Remove when definitive care is available. When correctly used, complication rate is exceedingly low.
    • Record time of placement, perform neuro exam, do not leave on for >120 min.
  • Consider elevating leg (although not necessarily immediately because you may aggravate a pelvic bony injury if present).

Massive Transfusion Protocol

MTP form

  • With increasing blood loss, giving crystalloid can cause dilutional anemia and coagulopathy.
  • MTPs are designed to mitigate the harm and impaired clot formation from the acidosis, hypothermia, and coagulopathy that develop with massive transfusion.
  • Ratio of RBC/FFP/PLT varies between institutions. 1:1:1 often recommended ratio for severe ongoing hemorrhage unlikely to be controlled quickly or adequately.

Patil V, Shetmahajan M. Massive Transfusion and Massive Transfusion Protocol. Indian Journal of Anesthesiology. 2014 Sept-Oct; 58(5): 590-595.

RBC Transfusion in Trauma (EAST)

  • Level 1: Transfusion indicated w/ evidence of hemorrhagic shock
  • Level 1: Transfusion may be indicated for acute hemorrhage and hemodynamic instability
  • Level 2: Use of only Hb as “trigger” for transfusion should be avoided. Decision should be based on: intravascular volume status, evidence of shock, duration and extent of anemia, and cardiopulmonary physiologic parameters

Classes of Hemorrhagic Shock

hemorrhagic shock classes

  • Do not forgot that the endogenous adrenergic state of trauma can artificially elevate BP.
    • Analgesics and anxiolytics will mitigate that stimulus.
  • Re-cycle the BP multiple times upon patient arrival.
Transexamic Acid in Trauma
  • Antifibrinolytic agent that binds plasminogen and blocks its conversion to plasmin, thus blocking dissolution of the fibrin clot

TXA

CRASH-2 Trial: Clinical Randomisation of an Antifibrinolytic in Significant Haemorrhage

  • Randomized placebo-controlled trial; n=20,000
  • Inclusion: significant hemorrhage (SBP <90, HR >110, or both) within 8 hrs of injury
  • Results:
    • 5% reduction in 28-day all-cause mortality; 16.0% to 14.5%, NNT 67
    • 8% reduction in death from bleeding; 5.7% to 4.9%, NNT 121
    • Greatest impact on reduction of bleeding death in:
      • Severe shock patients (SBP <75)
      • TXA given within 1 hr of injury
    • TXA given after 3 hrs associated w/ increased risk of death from bleeding (4.4% vs. 3.1%, RR 1.44)
      • No association w/ vasoocclusive events
      • Limitations: no standard RBC transfusion protocol, thus unclear whether effects directly from reversal of fibrinolysis
      • Take-aways:
        • 1 g administered over 10 min
        • Very cheap
        • Early administration is important. Consider pre-hospital use.

Napolitano J. et al. Tranexamic acid in trauma: how should we use it? J Trauma Acute Care Surg. 2013 Jun;74(6):1575-86.

Endotracheal Intubation in Trauma (EAST)
  • Level I Indication: hemorrhagic shock
  • Level III Indication: moderate cognitive impairment (GCS > 9-12), preoperative management
  • Level III: video laryngoscopy gives higher success rates when inline C-spine held
  • The decision to intubate a patient following traumatic injury is based on multiple factors: need for oxygenation and ventilation, mechanism of injury, predicted operative need, or concern for progression of disease.
  • Delay in intubation associated with increased mortality from 1.8% to 11.8% in one study (Miraflor E, Chuan K, Miranda MA, et al. Timing is everything: delayed intubation is associated with increased mortality in initially stable trauma patients. J Surg Res. 2011; 170: 117–121.)
ETI in the Trauma Bay
  • Waxing and waning levels of comprehension and confusion
  • Successfully passed 8.0 tube on 2nd attempt in 70 kg patient
    • Ketamine 75 mg
      • Good choice due to its sympathomimetic properties in this hypotensive patient
      • Remember that BP will drop when:
        • Endogenous adrenergic stimulus removed by sedative
        • Positive-pressure ventilation initiated
      • Rocuronium 100 mg
      • In-line manual C-spine stabilization
      • Never desaturated below 98%
        • Maintenance of O2 saturation points to value of adequate preoxygenation and apneic oxygenation
Apneic Oxygenation
  • Delivery of O2 from nasopharynx to lungs in absence of ventilation
  • Alveoli take up O2 even without diaphragmatic movements or lung expansion, due to concentration gradient. In apneic patient, O2 will move from alveoli into bloodstream. Less CO2 will move into alveoli from bloodstream. Essentially, given CO2’s high affinity for Hb, volume of CO2 returned to alveoli is less than volume of O2 removed from alveoli. Alveolar pressure thus decreases and becomes subatmospheric, generating a concentration gradient and thus flow from pharynx to alveoli of high FiO2 gas.

See evidence: Weingart S, Levitan R. Preoxygenation and Prevention of Desaturation During Emergency Airway Management. Annals Emerg Med. March 2012, 165-75.

 apneic ox in ICU

  • Found that apneic oxygenation made no difference in the ICU setting
  • Most of these patients intubated for resp failure.
    • ”For patients with pulmonary function so abnormal that provision of oxygen by mask or non-invasive ventilation was insufficient to avert intubation, providing 15 L/min by nasal cannula during intubation might be expected to be similarly ineffective.“
  • “Apneic oxygenation safe but ineffective in ICU.”
  • Would not necessarily change the practice of ED providers.
Reduction in Sedative Dose to Achieve Given Drug Effect

sedative in shockShafer S. Shock Values. Anesthesiology. Sept 2004, 567-8.
(from EMCrit)

  • This study calculated the reduction in dose to achieve a given drug effect in animals with hemorrhage, compared to animal controls.
  • Preferential perfusion to brain in shock.
    • Sedative reaches higher concentrations, faster onset, deeper effect.
      • Lower dose of sedative needed.
Increase in Rocuronium dose to achieve given drug effect

rocc

Ezri T. et al. Changes in onset time of rocuronium in patients pretreated with ephedrine and esmolol – the role of cardiac output. Acta Asesthiol Scand. 2003;47:1067-72.
(from EMCrit)

  • Dose of 0.6 mg/kg given in this study.
  • Statistically significant changes in cardiac output from administering Ephedrine and Esmolol.
  • Consider 1.6 mg/kg
  • In shock, less perfusion to periphery.
    • Higher dose of paralytic needed. You don’t want to be in a tube-now situation where you push the meds but the patient is not properly paralyzed.
Recap of Initial Interventions

3 peripheral IV lines
Pelvic binder with bed sheet
Tourniquet
Massive Transfusion Protocol
Transexamic Acid
Perineal laceration packed with gauze
Endotracheal intubation

Portable Plain Films in Trauma Bay

cxrpelvis

  • Had been concerned for pelvic fracture in this patient
  • Normal pelvis xray does not rule out pelvic fractures entirely, but does rule it out as the cause of hemodynamic instability.
Now what? (OR, CT, or Angio?)

 small council

Lower Arterial Trauma (EAST)
  • Level 2: Patients w/ hard signs of arterial injury should be surgically explored (no imaging). No need for CTA unless associated skeletal or shotgun injury. Restoration of perfusion in < 6 hrs to maximize limb salvage.
Hard Signs of Arterial Injury

 ecchydistal pulse

  • Pulsatile bleeding
  • Expanding hematoma
  • Absent distal pulses
  • Cold and pale limb
  • Palpable thrill
  • Audible bruit
  • Blunt trauma injures vessels by crushing, distracting, or shearing. This results in contusion to the vessel, which may extend along its length. An intimal flap may be formed which will lead to thrombosis or dissection and subsequent rupture.
  • 1-4% of those patients without hard signs will have delayed presentation of undetected injury.
Soft Signs of Arterial Injury

foot drophematoma

  • Peripheral nerve deficit
  • Moderate hemorrhage
  • Reduced but palpable pulse
  • Injury close to major artery
  • Small hematoma
In actuality, our patient was taken to CT scan
  • R thigh steadily enlarging, more ecchymotic
  • Perineal laceration bleeding more heavily
    • Repacked w/ more gauze
  • IR paged in anticipation of vascular bleed requiring embolization
  • BP dropped to 80/60
    • Hold pressors in hemorrhagic shock
      • Raising BP will increase hemorrhage from the vessel injury and dislodge any clot that has formed
      • For unconscious patients, SBP ~70 is adequate in absence of significant brain injury
      • Inotropes will increase myocardial work in absence of adequate preload
CTA of Lower Extremities

cta1cta2cta3cta4

Recap ED Course

19 y/o M no PMH BIBEMS s/p being struck by garbage truck. Concern for massive bleeding into R thigh compartment, w/ distal extremity hypoperfusion. Pelvis bound, MTP initiated, TXA given. Intubated due to waxing/waning comprehension. Portable pelvis films w/o pelvis or femur fracture. Hypotensive in CT scanner, push-dose pressors given. CT showing popliteal artery injury. Taken to OR.

 

Additional EMDOCS references
http://www.emdocs.net/peripheral-vascular-injury-management/
http://www.emdocs.net/knee-dislocation-pearls-and-pitfalls/

2 thoughts on “Popliteal Artery Injury from Blunt Trauma: A Trauma Case”

  1. This is a great case that touched on a number of important topics in trauma and critical care management. Was there a reason that push-dose pressers given in this case (since you correctly point out the need to not give pressers in hemorrhagic shock)?

    1. I spoke with the team: It sounds like the push-dose Phenylephrine had been given almost reflexively on seeing the SBP drop, but this error was very soon thereafter recognized.

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