- Email: [email protected]
Medical Decisionmaking and the San Francisco Syncope Rule
Correspondence 1. Driscoll P, Wardrope J. ATLS: past, present, and future. Emerg Med J. 2005;22:2-3. 2. Nolan JP. Advanced trauma life support in the United Kingdom: time to move on. Emerg Med J. 2005;22:3-4. 3. Davis M. Should there be a UK based advanced trauma course? Emerg Med J. 2005;22:5-6. 4. Luke C. ATLS: there are alternatives. Emerg Med J. 2006;23:160. 5. Oral presentation (unpublished): ETC concept to course, Gwinutt, C. Presented at: 8th Congress of the European Resuscitation Council, May 12th 2006; Stavanger, Norway.
Symposium on the Definition and Management of Anaphylaxis To the Editor: Sampson and colleagues should be congratulated for their condensed and well-focused report of the recent National Institute of Allergy and Infectious Disease Symposium on Anaphylaxis.1 One additional element should be noted regarding outpatient follow-up and management. The discharging emergency physician should strongly recommend the purchase of any commercially available medical alert bracelet or necklace.2 Given the rapid onset, severity, and nature of anaphylactic symptoms, a patient in severe anaphylaxis may be unable to relate to first responders their relevant history. A readily apparent bracelet may lead to the appropriate intervention with alacrity. Eric Koscove, MD Emergency Department Kaiser Permanente Medical Center Santa Clara, CA doi:10.1016/j.annemergmed.2006.06.052 1. Sampson HA, Munoz-Furlong A, Campbell RL, et al. Second Symposium on the Definition and Management of Anaphylaxis: Summary Report - Second National Institute of Allergy and Infectious Disease/Fool Allergy and Anaphylaxis Network Symposium. Ann Emerg Med. 2006;47:373-380. 2. Drain KL, Volcheck GW. Preventing and managing drug-induced anaphylaxis. Drug Saf. 2001;24:843-53.
In reply: Thank you for your thoughtful comments regarding our report on the National Institute of Allergy, Infectious Disease– Second Symposium on the Definition and Management of Anaphylaxis: Summary Report.1 Dr. Koscove commented on the need to recommend the purchase of a medical alert bracelet or necklace.2 While this particular measure was not discussed at this symposium and there is not a great deal of evidence to substantiate or refute its use, there is anecdotal support and a sound rationale for the use of an identifying mark for this purpose, and we are in support of Dr. Koscove’s comments. Logistically, the information on obtaining such medic alert tag might be best handled by the patient’s primary care or allergist office. 762 Annals of Emergency Medicine
Wyatt W. Decker, MD Department of Emergency Medicine Mayo Clinic College of Medicine Rochester, MN Hugh A. Sampson, MD Mount Sinai School of Medicine New York, NY Anne Muñoz-Furlong, BA Food Allergy and Anaphylaxis Network Fairfax, VA doi:10.1016/j.annemergmed.2006.06.051 1. Sampson HA, Munoz-Furlong A, Campbell RL, et al. Second Symposium on the Definition and Management of Anaphylaxis: Summary Report–Second National Institute of Allergy and Infectious Disease/Food Allergy and Anaphylaxis Network Symposium. Ann Emerg Med. 2006;47:373-380. 2. Drain KL, Volcheck GW. Preventing and managing drug-induced anaphylaxis. Drug Saf. 2001;24:373-380.
Medical Decisionmaking and the San Francisco Syncope Rule To the Editor: We would like to thank Drs. Miller and Hoekstra for their generally positive editorial of our work; however, we disagree how with how they suggest the San Francisco Syncope Rule may be used.1,2 Syncope is a complex symptom with varying etiologies making the derivation and validation of a rule that is 100% sensitive likely impossible. In particular, the true definition of syncope can be controversial, variables in any rule require interpretation and the short term outcomes from syncope are composite outcomes that may not always be interpreted correctly. Simple rules with clear outcomes have had problems when externally validated and we see greater challenges with the San Francisco Syncope Rule.3 The fact that the San Francisco Syncope Rule may not be externally validated with 100% sensitivity or our precise accuracy does not lessen its value. The editorial suggests that the rule may be used on the “front end” to supersede physician judgment and if so mistakenly discharge patients with symptoms of an acute myocardial infarction. Furthermore, it suggests that the lower bounds of sensitivity may cause one to incorrectly classify 11 of 100 patients who could be sent home to suffer an adverse outcome. This is absolutely not how the San Francisco Syncope Rule should be used. No decision rule should be used to override common sense and as Miller and Hoekstra correctly point out rules claiming to supersede judgment need to be virtually 100% sensitive with extremely narrow confidence intervals. The San Francisco Syncope Rule clearly does not have the sensitivity for this type of application, but we believe it does have value in the risk stratification of Volume , . : December
Correspondence patients. For example, data from the lower bounds of our 95% confidence intervals would yield a negative likelihood ratio of 0.2 and decrease the pretest probability of someone with a 5% chance of a bad outcome to less than 1%. This is important because we determined that physicians correctly felt that well over 50% of emergency department patients with syncope had a less than 5% chance of suffering a bad outcome, but still admitted a large portion of these patients.4 Our rule may allow them to increase their self-confidence in their judgment and further reduce risk to ⬍ 1% in most of these patients. While the risk is still not zero, it is better than the risk physicians take when discharging low-risk patients with chest pain.5 Unfortunately, there will never be a validated multi-center “rule” for syncope that is 100% sensitive with narrow enough confidence intervals allowing one to use the rule to supersede physician judgment as Miller and Hoekstra suggest. Nevertheless, we believe that physician judgment for patients with syncope is very good and that our work adds to the existing evidence in the literature that will allow physicians to improve the efficiency of their decisionmaking. James V. Quinn, MD, MS Division of Emergency Medicine Stanford University Palo Alto, CA Daniel McDermott, MD Department of Medicine University of California, San Francisco San Francisco, CA doi:10.1016/j.annemergmed.2006.06.050 1. Quinn J, Stiell I, McDermott D, et al. Prospective validation of the San Francisco Syncope Rule to predict patients with serious outcomes. Ann Emerg Med. 2006;47:448-454. 2. Miller CD, Hoekstra JW. Prospective validation of the San Francisco Syncope Rule: will it change practice? Ann Emerg Med. 2006;47: 455-456.
Volume , . : December
3. Stiell IG, Clement CM, McKnight RD, et al. The Canadian C-spine rule versus the NEXUS low-risk criteria in patients with trauma. N Engl J Med. 2003;349:2510-2518. 4. Quinn JV, Stiell IG, McDermott DA, et al. San Francisco Syncope Rule vs. physician judgment and decision making. Am J Emerg Med. 2005;23:782-786. 5. McCarthy BD, Beshansky JR, D’Agostino RB, et al. Missed diagnoses of acute myocardial infarction in the emergency department: results from a multicenter study. Ann Emerg Med. 1993;22:579-582.
In reply: While reading Drs. Quinn and McDermott’s letter to the editor, I fear our opinion of the San Francisco Syncope Rule validation study may have been ambiguous and appreciate the opportunity for clarification. Our editorial is in agreement with the views expressed by Dr. Quinn. We both agree upon the importance of not using this decision rule “up-front” as this differs from how the rule was derived and validated. Furthermore, we also pointed out the limitations of allowing a decision rule to supersede clinical judgment and strongly agree this clinical decision rule should not be used in this manner. Thus, it was not our intent to suggest the manner in which the San Francisco Syncope Rule should be applied. In fact, to the contrary, our editorial intended to focus on the potential for misuse of clinical decision rules including the San Francisco Syncope Rule. Finally, Dr. Quinn and colleagues should be commended for this work which undoubtedly will assist in the risk stratification of patients with this potentially deadly symptom. Chadwick D. Miller, MD James William Hoekstra, MD Department of Emergency Medicine Wake Forest University Health Sciences Winston-Salem, NC doi:10.1016/j.annemergmed.2006.07.948
Annals of Emergency Medicine 763
Symposium on the Definition and Management of Anaphylaxis To the Editor: Sampson and colleagues should be congratulated for their condensed and well-focused report of the recent National Institute of Allergy and Infectious Disease Symposium on Anaphylaxis.1 One additional element should be noted regarding outpatient follow-up and management. The discharging emergency physician should strongly recommend the purchase of any commercially available medical alert bracelet or necklace.2 Given the rapid onset, severity, and nature of anaphylactic symptoms, a patient in severe anaphylaxis may be unable to relate to first responders their relevant history. A readily apparent bracelet may lead to the appropriate intervention with alacrity. Eric Koscove, MD Emergency Department Kaiser Permanente Medical Center Santa Clara, CA doi:10.1016/j.annemergmed.2006.06.052 1. Sampson HA, Munoz-Furlong A, Campbell RL, et al. Second Symposium on the Definition and Management of Anaphylaxis: Summary Report - Second National Institute of Allergy and Infectious Disease/Fool Allergy and Anaphylaxis Network Symposium. Ann Emerg Med. 2006;47:373-380. 2. Drain KL, Volcheck GW. Preventing and managing drug-induced anaphylaxis. Drug Saf. 2001;24:843-53.
In reply: Thank you for your thoughtful comments regarding our report on the National Institute of Allergy, Infectious Disease– Second Symposium on the Definition and Management of Anaphylaxis: Summary Report.1 Dr. Koscove commented on the need to recommend the purchase of a medical alert bracelet or necklace.2 While this particular measure was not discussed at this symposium and there is not a great deal of evidence to substantiate or refute its use, there is anecdotal support and a sound rationale for the use of an identifying mark for this purpose, and we are in support of Dr. Koscove’s comments. Logistically, the information on obtaining such medic alert tag might be best handled by the patient’s primary care or allergist office. 762 Annals of Emergency Medicine
Wyatt W. Decker, MD Department of Emergency Medicine Mayo Clinic College of Medicine Rochester, MN Hugh A. Sampson, MD Mount Sinai School of Medicine New York, NY Anne Muñoz-Furlong, BA Food Allergy and Anaphylaxis Network Fairfax, VA doi:10.1016/j.annemergmed.2006.06.051 1. Sampson HA, Munoz-Furlong A, Campbell RL, et al. Second Symposium on the Definition and Management of Anaphylaxis: Summary Report–Second National Institute of Allergy and Infectious Disease/Food Allergy and Anaphylaxis Network Symposium. Ann Emerg Med. 2006;47:373-380. 2. Drain KL, Volcheck GW. Preventing and managing drug-induced anaphylaxis. Drug Saf. 2001;24:373-380.
Medical Decisionmaking and the San Francisco Syncope Rule To the Editor: We would like to thank Drs. Miller and Hoekstra for their generally positive editorial of our work; however, we disagree how with how they suggest the San Francisco Syncope Rule may be used.1,2 Syncope is a complex symptom with varying etiologies making the derivation and validation of a rule that is 100% sensitive likely impossible. In particular, the true definition of syncope can be controversial, variables in any rule require interpretation and the short term outcomes from syncope are composite outcomes that may not always be interpreted correctly. Simple rules with clear outcomes have had problems when externally validated and we see greater challenges with the San Francisco Syncope Rule.3 The fact that the San Francisco Syncope Rule may not be externally validated with 100% sensitivity or our precise accuracy does not lessen its value. The editorial suggests that the rule may be used on the “front end” to supersede physician judgment and if so mistakenly discharge patients with symptoms of an acute myocardial infarction. Furthermore, it suggests that the lower bounds of sensitivity may cause one to incorrectly classify 11 of 100 patients who could be sent home to suffer an adverse outcome. This is absolutely not how the San Francisco Syncope Rule should be used. No decision rule should be used to override common sense and as Miller and Hoekstra correctly point out rules claiming to supersede judgment need to be virtually 100% sensitive with extremely narrow confidence intervals. The San Francisco Syncope Rule clearly does not have the sensitivity for this type of application, but we believe it does have value in the risk stratification of Volume , . : December
Correspondence patients. For example, data from the lower bounds of our 95% confidence intervals would yield a negative likelihood ratio of 0.2 and decrease the pretest probability of someone with a 5% chance of a bad outcome to less than 1%. This is important because we determined that physicians correctly felt that well over 50% of emergency department patients with syncope had a less than 5% chance of suffering a bad outcome, but still admitted a large portion of these patients.4 Our rule may allow them to increase their self-confidence in their judgment and further reduce risk to ⬍ 1% in most of these patients. While the risk is still not zero, it is better than the risk physicians take when discharging low-risk patients with chest pain.5 Unfortunately, there will never be a validated multi-center “rule” for syncope that is 100% sensitive with narrow enough confidence intervals allowing one to use the rule to supersede physician judgment as Miller and Hoekstra suggest. Nevertheless, we believe that physician judgment for patients with syncope is very good and that our work adds to the existing evidence in the literature that will allow physicians to improve the efficiency of their decisionmaking. James V. Quinn, MD, MS Division of Emergency Medicine Stanford University Palo Alto, CA Daniel McDermott, MD Department of Medicine University of California, San Francisco San Francisco, CA doi:10.1016/j.annemergmed.2006.06.050 1. Quinn J, Stiell I, McDermott D, et al. Prospective validation of the San Francisco Syncope Rule to predict patients with serious outcomes. Ann Emerg Med. 2006;47:448-454. 2. Miller CD, Hoekstra JW. Prospective validation of the San Francisco Syncope Rule: will it change practice? Ann Emerg Med. 2006;47: 455-456.
Volume , . : December
3. Stiell IG, Clement CM, McKnight RD, et al. The Canadian C-spine rule versus the NEXUS low-risk criteria in patients with trauma. N Engl J Med. 2003;349:2510-2518. 4. Quinn JV, Stiell IG, McDermott DA, et al. San Francisco Syncope Rule vs. physician judgment and decision making. Am J Emerg Med. 2005;23:782-786. 5. McCarthy BD, Beshansky JR, D’Agostino RB, et al. Missed diagnoses of acute myocardial infarction in the emergency department: results from a multicenter study. Ann Emerg Med. 1993;22:579-582.
In reply: While reading Drs. Quinn and McDermott’s letter to the editor, I fear our opinion of the San Francisco Syncope Rule validation study may have been ambiguous and appreciate the opportunity for clarification. Our editorial is in agreement with the views expressed by Dr. Quinn. We both agree upon the importance of not using this decision rule “up-front” as this differs from how the rule was derived and validated. Furthermore, we also pointed out the limitations of allowing a decision rule to supersede clinical judgment and strongly agree this clinical decision rule should not be used in this manner. Thus, it was not our intent to suggest the manner in which the San Francisco Syncope Rule should be applied. In fact, to the contrary, our editorial intended to focus on the potential for misuse of clinical decision rules including the San Francisco Syncope Rule. Finally, Dr. Quinn and colleagues should be commended for this work which undoubtedly will assist in the risk stratification of patients with this potentially deadly symptom. Chadwick D. Miller, MD James William Hoekstra, MD Department of Emergency Medicine Wake Forest University Health Sciences Winston-Salem, NC doi:10.1016/j.annemergmed.2006.07.948
Annals of Emergency Medicine 763