Trauma, VS, and Shock
Here is a brief summary of my 30-minute presentation:
No single vital sign is reliable to determine severity of injury or degree of traumatic shock. There have been papers that indicate correlation of mortality/injury severity with increased HR, RR > 25, BP <90, and GCS < 14.[i]
Location of palpable pulse does not correlate accurately with estimated BP, is no longer taught in ATLS, and should not be used as a surrogate to estimate blood pressure. It can be useful to assess improvement or decline in a single patient over time.[ii],[iii]
When automated BP measurements have been studied, they significantly overestimate BP in hypotensive trauma patients. Consider using a manual cuff if there is any question of the accuracy of the BP. Definitely cycle the initial BP two or three times to verify.[iv]
ATLS guidelines for degree of shock are not based on firm literature, and will tend to underestimate the degree of shock based on HR and BP. Do not rely on this to assess stability of your trauma patient – take the entire picture into account.[v],[vi],[vii],[viii],[ix]
Shock Index is also not completely reliable, but may be more sensitive than HR or BP alone to assess severity of injury and degree of shock. SI is calculated as HR/SBP. Results > 0.9 suggest increased level of injury and shock.[x],[xi],[xii],[xiii]
SBP < 110mmHg may be a more sensitive indicator of severity of injury, level of hemorrhagic shock, and impending mortality than the traditional 90mmHg. This previous cutoff is not based in any specific literature, and is used by arbitrary convention, likely based on estimated needs for cerebral and renal perfusion.[xiv],[xv],[xvi],[xvii]
If you’re in the mood for some easy listening on the topic of trauma resuscitation, I suggest the following:
http://emcrit.org/podcasts/trauma-resuscitation-dutton/
http://emcrit.org/podcasts/severe-trauma-karim-brohi/
https://www.emrap.org/episode/april2005/trauma
Disclaimer: My lecture and EMSGH blog post are a summary of my personal opinions, based on extensive literature review, well-vetted online podcast and blogs, training I have received both within and outside of SGH/DMC, and personal experience. Any implementation into your personal practice should be thoroughly discussed with your attending, and if any question persists, with ED and hospital administration.
[i] Pacagnella RC, Souza JP, Durocher J, Perel P, Blum J, Winikoff B, Gülmezoglu AM. A systematic review of the relationship between blood loss and clinical signs. PLoS One. 2013;8(3):e57594. doi: 10.1371/journal.pone.0057594. Epub 2013 Mar 6. Review. Erratum in: PLoS One. 2013;8(6). PMID: 23483915
[ii] Deakin CD, Low JL. Accuracy of the advanced trauma life support guidelines for predicting systolic blood pressure using carotid, femoral, and radial pulses: observational study. BMJ. 2000 Sep 16;321(7262):673-4. PMID: 10987771
[iii] Poulton TJ. ATLS paradigm fails. Ann Emerg Med. 1988 Jan;17(1):107. PubMed PMID: 3337405
[iv] Davis JW, Davis IC, Bennink LD, Bilello JF, Kaups KL, Parks SN. Are automated blood pressure measurements accurate in trauma patients? J Trauma. 2003 Nov;55(5):860-3. PubMed PMID: 14608157
[v] Guly HR, Bouamra O, Little R, Dark P, Coats T, Driscoll P, Lecky FE. Testing the validity of the ATLS classification of hypovolaemic shock. Resuscitation. 2010 Sep;81(9):1142-7. PMID: 20619954
[vi] Guly HR, Bouamra O, Spiers M, Dark P, Coats T, Lecky FE; Trauma Audit and Research Network. Vital signs and estimated blood loss in patients with major trauma: testing the validity of the ATLS classification of hypovolaemic shock. Resuscitation. 2011 May;82(5):556-9. PMID: 21349628
[vii] Mutschler M, Nienaber U, Brockamp T, Wafaisade A, Wyen H, Peiniger S, Paffrath T, Bouillon B, Maegele M; TraumaRegister DGU. A critical reappraisal of the ATLS classification of hypovolaemic shock: does it really reflect clinical reality? Resuscitation. 2013 Mar;84(3):309-13. PMID: 22835498
[viii] Mutschler M, Paffrath T, Wölfl C, Probst C, Nienaber U, Schipper IB, Bouillon B, Maegele M. The ATLS(®) classification of hypovolaemic shock: a well established teaching tool on the edge? Injury. 2014 Oct;45 Suppl 3:S35-8. PMID: 25284231
[ix] Mutschler M, Hoffmann M, Wölfl C, Münzberg M, Schipper I, Paffrath T, Bouillon B, Maegele M. Is the ATLS classification of hypovolaemic shock appreciated in daily trauma care? An online-survey among 383 ATLS course directors and instructors. Emerg Med J. 2015 Feb;32(2):134-7. doi: PMID: 24071947
[x] Bruijns SR, Guly HR, Bouamra O, Lecky F, Lee WA. The value of traditional vital signs, shock index, and age-based markers in predicting trauma mortality. J Trauma Acute Care Surg. 2013 Jun;74(6):1432-7. PMID: 23694869
[xi] Schafer K, Van Sickle C, Hinojosa-Laborde C, Convertino VA. Physiologic mechanisms underlying the failure of the “shock index” as a tool for accurate assessment of patient status during progressive simulated hemorrhage. J Trauma Acute Care Surg. 2013 Aug;75(2 Suppl 2):S197-202. PMID: 23883908
[xii] McNab A, Burns B, Bhullar I, Chesire D, Kerwin A. An analysis of shock index as a correlate for outcomes in trauma by age group. Surgery. 2013 Aug;154(2):384-7. PMID: 23889965
[xiii] Mutschler M, Nienaber U, Münzberg M, Wölfl C, Schoechl H, Paffrath T, Bouillon B, Maegele M; TraumaRegister DGU. The Shock Index revisited – a fast guide to transfusion requirement? A retrospective analysis on 21,853 patients derived from the TraumaRegister DGU. Crit Care. 2013 Aug 12;17(4):R172. PMID: 23938104
[xiv] Eastridge BJ, Salinas J, McManus JG, Blackburn L, Bugler EM, Cooke WH, Convertino VA, Wade CE, Holcomb JB. Hypotension begins at 110 mm Hg: redefining “hypotension” with data. J Trauma. 2007 Aug;63(2):291-7; discussion 297-9. PMID: 17693826
[xv] Edelman DA, White MT, Tyburski JG, Wilson RF. Post-traumatic hypotension: should systolic blood pressure of 90-109 mmHg be included? Shock. 2007 Feb;27(2):134-8. PMID: 17224786
[xvi] Hasler RM, Nuesch E, Jüni P, Bouamra O, Exadaktylos AK, Lecky F. Systolic blood pressure below 110 mm Hg is associated with increased mortality in blunt major trauma patients: multicentre cohort study. Resuscitation. 2011 Sep;82(9):1202-7. PMID: 21632168
[xvii] Hasler RM, Nüesch E, Jüni P, Bouamra O, Exadaktylos AK, Lecky F. Systolic blood pressure below 110 mmHg is associated with increased mortality in penetrating major trauma patients: Multicentre cohort study. Resuscitation. 2012 Apr;83(4):476-81. PMID: 22056618
