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. 2001 Mar 3;322(7285):552.

Accuracy of ATLS guidelines for predicting systolic blood pressure

Authors' core assertion was wrong

Ian S Russell 1
PMCID: PMC1119746  PMID: 11230089

Editor—I commend the BMJ for allowing access to the editorial decision making process via the BMJ's website. It gives a fair measure of explanation why a paper was published.

On reading the peer reviews for Deakin and Low's paper on advanced trauma life support guidelines for predicting systolic blood pressure it is evident that the referee and statistician have accepted without criticism the authors' core assertion.1 This is that the advanced trauma life support course teaches that if only the patient's carotid pulse is palpable then the systolic blood pressure is 60-70 mm Hg; if both the carotid and femoral pulses are palpable then the systolic blood pressure is 70-80 mm Hg; and if the radial pulse is also palpable then the systolic blood pressure is >80 mm Hg.

Unfortunately, this is entirely wrong and constitutes no part of the current course or manual.2 The authors cite a guideline from 1985,3 but the manual is currently in its sixth edition, with a further update due for publication this year, 2001.

One redeeming feature of the paper is that it shows (albeit at lower intra-arterial systolic pressures) an observable relation between the palpability of pulses and systolic blood pressure. But the design of the paper is open to question. Why were only 20 patients included (especially over three years)? What conditions did they have? If they had arterial lines inserted I hope that they had already received initial resuscitation. Some were undergoing operation—did they have anaesthesia? What was the status of the observer?

If we are all planning to keep our fingers on the pulses then we really must stay up to date and reaccredited.

References

  • 1.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;321:673–674. doi: 10.1136/bmj.321.7262.673. . (16 September.) [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 2.American College of Surgeons. Advanced trauma life support for doctors. 6th ed. Chicago: ACS; 1997. [Google Scholar]
  • 3.Collicott PE. Advanced trauma life support course for physicians. Chicago: American College of Surgeons; 1985. [Google Scholar]
BMJ. 2001 Mar 3;322(7285):552.

No one relies on pulse checks alone for subsequent clinical decision making

Zak Baig 1

Editor—Deakin and Low have shown that if you follow the principles of advanced trauma life support you tend to overestimate the patient's blood pressure, which leads to under-resuscitation.1-1 They used invasive methods of blood pressure recording, possibly insertion of an arterial line. In reality, overestimation leads to “secondary survey” anyway (assuming that airway and breathing were normal); checking blood pressure is part of that. Any low blood pressure will then be picked up, and resuscitation will be started accordingly.

I have worked in different accident and emergency and trauma departments, and I have never come across anyone who relied on pulse checks alone in subsequent clinical decision making. This is because we already know that feeling a pulse has never correlated well with the blood pressure. We also know that the advanced trauma life support guidelines teach us very basic principles of resuscitation of trauma victims and that often we have to use our brain to evaluate further, investigate, and treat a sick patient.

I was disappointed that the authors did not compare a standard method of checking blood pressure (cuff and sphygmomanometer) with the invasive monitoring. I am sure that, if they had done, it would have given a different value. What do we do then? We cannot put an arterial line in every patient to monitor blood pressure.

References

  • 1-1.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;321:673–674. doi: 10.1136/bmj.321.7262.673. . (16 September.) [DOI] [PMC free article] [PubMed] [Google Scholar]
BMJ. 2001 Mar 3;322(7285):552.

Earlier dogma seems to have been dropped now

Gareth Quin 1,2, Gerard McCarthy 1,2

Editor—Deakin and Low tested the relation between palpable pulses and systolic blood pressure.2-1 We both remember being assured of this relation as students (in the days before evidence based medicine); the authors' paper questions this medical school dogma.

Advanced trauma life support is often accused of didacticism on many fronts, but we do not think that it is guilty on this occasion. We are both instructors in advanced trauma life support and have been involved at provider level since 1991. We have no recollection of this being taught as core course knowledge. We note that the offending guideline was published in 1985 and assume that it has since been dropped.

Advanced trauma life support teaches the need for rapid discovery and aggressive treatment of initial, recurrent, or persistent hypovolaemia. The finding of an absent pulse at any site, other than for local reasons, should be presumed to signify appreciable hypovolaemia. The paper supports this.

References

  • 2-1.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;321:673–674. doi: 10.1136/bmj.321.7262.673. . (16 September.) [DOI] [PMC free article] [PubMed] [Google Scholar]
BMJ. 2001 Mar 3;322(7285):552.

Author's reply

Charles D Deakin 1

Editor—The advanced trauma life support course introduced the relation between palpable pulses and blood pressure in its first edition in 1985. I agree that the paper should have clarified that the course has now stopped teaching this relation. In a short report, however, there was not enough space to discuss the evolution of the guidelines.

The reference in our paper clearly refers to the 1985 guidelines. By quoting a different reference, Russell is wrong in stating that our core assertion is incorrect. The original advanced trauma life support guidelines have been disseminated widely and continue to be taught and cited.3-1–3-3 These unvalidated guidelines remain an often used method of quickly assessing hypotensive patients, and early advanced trauma life support teaching (and instructors) must take responsibility for their international dissemination and use.

Russell criticises the design of the paper in that only 20 patients were collected over three years. I accept that this was a small study, but it nevertheless generates data that cast doubt on the relation between pulses and blood pressure. Recruitment was limited by the number of hypotensive trauma patients seen at this hospital each year. Russell is correct in assuming that the patients received initial resuscitation, and it is for this reason that the number was limited. Are we being criticised for adequate resuscitation that has prevented hypotension in most patients? Collecting data over three years is hardly a cause for criticism.

Russell questions the 29 data points from 20 patients. We stated in the paper that “Not all pulses were palpable when a reading was taken because of impaired patient access.” The raw data were submitted to the BMJ, which declined to publish them.

Baig states he has never come across anyone who relied on pulse checks alone. I have worked in several trauma systems in the United Kingdom, particularly in the prehospital arena, where quick assessment of palpable pulses is used as an initial assessment of blood pressure and management decisions are made on the basis of pulses alone. Baig is also incorrect in stating that “we already know that feeling a pulse has never correlated well with the blood pressure.” We do not.

Baig is disappointed that the study did not compare invasive and non-invasive (cuff) measurements. This was not our aim. As stated in the paper, non-invasive blood pressure measurement in hypotensive patients is inaccurate, and we deliberately avoided this measurement technique. Blood pressure was changing rapidly in many of the patients, and non-invasive pressure measurement lags behind changes in actual blood pressure. It would be unethical to wait while non-invasive pressure was measured before treating hypotension.

References

  • 3-1.Pre-Hospital Trauma Life Support Committee; National association of Emergency Medical Technicians in cooperation with Committee on Trauma; American College of Surgeons. Prehospital trauma life support—instructors' manual. 3rd ed. St Louis, MO: Mosby; 1995. [Google Scholar]
  • 3-2.Dalton AL, Limmer D, Mistovich JJ. Advanced medical life support. New Jersey: Prentice Hall; 1999. [Google Scholar]
  • 3-3.Eaton CJ. Essentials of immediate medical care. Edinburgh: Churchill Livingstone; 1999. [Google Scholar]

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