Category: Evidence-based Approach

Cryptic Shock – Identifying the Unseen (PART 1)

~ Gayatri Lekshmi Madhavan, India ~ Leave a comment

Case Presentation

A 68-year-old man presented to the Emergency Department with complaints of breathing difficulty and fever for three days. The patient is a known diabetic and hypertensive.

After detailed history taking, clinical examination, and radiological workup, the patient was diagnosed with right-sided lobar pneumonia (Community-acquired) and immediately started on intravenous antibiotics. In addition, necessary cultures and blood samples were taken for evaluation.

At the time of presentation, his vitals were HR – 92/min, BP – 130/70mmHg, RR – 30/min, SpO2 – 90% with RA à 96% with 2L O2. He underwent bladder catheterization.

During the 1st hour in the ER, the patient had a very low urine output, which continued for the next few hours. Lactate levels were more than 4mmol/L.

Based on the symptoms, oliguria, and hyperlactatemia, the patient was diagnosed to have sepsis and was initiated on fluid resuscitation. After 2 hours, the patient remained oliguric still, and his BP declined to 120/70mmHg.

After 6 hours, the patient’s BP became 110/60mmHg (MAP – 77). He became anuric and developed altered sensorium. Since he did not meet the criteria of septic shock, he was continued on IV fluids and antibiotics.

After 12 hours, the BP became 80/40mmHg (MAP – 63mmHg) à developed Multiorgan Dysfunction Syndrome. He was then started on vasopressors and mechanical ventilation.

By day 3, the patient further deteriorated and went into cardiac arrest. ROSC was not achieved.

Case Analysis

The treatment initiated was based on protocols like Surviving Sepsis Guidelines and Septic Shock management. So how did the process fail in order to adequately resuscitate this patient? Could something have been done more differently?

The case you read above is a very common scenario. Approximately 30% of the people coming to the ER are hypertensive, and around 10% have diabetes mellitus. They form a huge population, among whom the incidence of any other disease increases their morbidity and early mortality.

Before we delve into the pathology in these patients, let us look at the basic definitions of shock/hypotension.

  • SBP < 90mmHg
  • MAP < 65 mmHg
  • Decrease in SBP > 40mmHg
  • Organ Dysfunction
  • Hyperlactatemia
  • Shock: A state of circulatory insufficiency that creates an imbalance between tissue oxygen supply (delivery) and demand (consumption), resulting in end-organ dysfunction.
  • Septic Shock: Adult patients can be identified using the clinical criteria of hypotension requiring the use of vasopressors to maintain MAP of 65mmHg or greater and having a serum lactate level greater than 2 mmol/L persisting after adequate fluids resuscitation.
  • Cryptic Shock: Presence of hyperlactatemia (or systemic hypoperfusion) in a case of sepsis with normotension.

Based on all the information given above;

  1. what do you think was wrong with our patient?
  2. What kind of shock did he have?
  3. Could we have managed him any other way?
  4. When should we have started inotropes?
  5. Did the fact that he was hypertensive and diabetic have to do with his early deterioration? If so, how?
  6. When did the patient-first develop signs of shock?
  7. What are the different signs and symptoms of shock, and how are they recognized in the ER?

Keep your answers ready… 

Part 2 of Cryptic Shock Series – Vascular Pathology and What is considered ‘Shock’ in Hypertensive patients

Part 3 of Cryptic Shock Series – Individualised BP management

Part 4 of Cryptic Shock Series – Latest Trends

References and Further Reading

  1. Ranzani OT, Monteiro MB, Ferreira EM, Santos SR, Machado FR, Noritomi DT; Grupo de Cuidados Críticos Amil. Reclassifying the spectrum of septic patients using lactate: severe sepsis, cryptic shock, vasoplegic shock and dysoxic shock. Rev Bras Ter Intensiva. 2013 Oct-Dec;25(4):270-8. doi: 10.5935/0103-507X.20130047.
  2. Singer M, Deutschman CS, Seymour CW, Shankar-Hari M, Annane D, Bauer M, Bellomo R, Bernard GR, Chiche JD, Coopersmith CM, Hotchkiss RS, Levy MM, Marshall JC, Martin GS, Opal SM, Rubenfeld GD, van der Poll T, Vincent JL, Angus DC. The Third International Consensus Definitions for Sepsis and Septic Shock (Sepsis-3). JAMA. 2016 Feb 23;315(8):801-10. doi: 10.1001/jama.2016.0287.
  3. Shankar-Hari M, Phillips GS, Levy ML, Seymour CW, Liu VX, Deutschman CS, Angus DC, Rubenfeld GD, Singer M; Sepsis Definitions Task Force. Developing a New Definition and Assessing New Clinical Criteria for Septic Shock: For the Third International Consensus Definitions for Sepsis and Septic Shock (Sepsis-3). JAMA. 2016 Feb 23;315(8):775-87. doi: 10.1001/jama.2016.0289.
  4. Education Resources – Sepsis Trust
  5. The Research of Predicting Septic Shock – International Emergency Medicine Education Project (iem-student.org)
  6. Sepsis – International Emergency Medicine Education Project (iem-student.org)
  7. Empiric Antibiotics for Sepsis in the ED Infographics – International Emergency Medicine Education Project (iem-student.org)
  8. Sepsis – An Overview and Update – International Emergency Medicine Education Project (iem-student.org)
Cite this article as: Gayatri Lekshmi Madhavan, India, "Cryptic Shock – Identifying the Unseen (PART 1)," in International Emergency Medicine Education Project, October 4, 2021, https://iem-student.org/2021/10/04/cryptic-shock/, date accessed: December 11, 2023

Suicide – An Emergency Priority of Public Health Care

Suicide An Emergency
~ Leah Sarah Peer, Canada ~ Leave a comment

A significant number of emergency department visits annually arise as a result of intentional self-harm. Although no accurate description explains what leads to suicide or what comes after, it is a multifaceted phenomenon of public health urgency during a global health crisis. In the United States alone, suicide is the 10th leading cause of death and worldwide claims up to 800,000 lives each year. The international community must unite to come up with solutions to prevent the loss of life, as every single life lost is one too many.

With the COVID-19 pandemic, such an emergency naturally affects both individuals’ health and well-being and the communities in which they live. Unprecedented times unleash various emotional reactions from isolation, grief and trauma to other unhealthy behaviours, noncompliance with public health guidelines and the exacerbation of mental health conditions. While those who’ve been emotionally, sexually or physically abused in the past are more vulnerable to the psychosocial effects of a crisis, supportive interventions such as the Zero Suicide program and Cognitive Behavioural Therapy designed to promote wellness and enhance coping should be implemented [1]. 

In honour of World Suicide Prevention Week, and World Suicide Prevention Day held on the 10th of September every year, it is important to raise attention to the global importance of suicide prevention. Suicide impacts all people and particularly the world’s most marginalized and discriminated groups. It is a huge problem in developed countries and just as serious in low-and middle income countries where resources and access to healthcare professionals are scarce. In many regions of the world, the taboo and stigma surrounding suicide persist, causing people in need of help to be left alone. 

Suicide prevention with awareness campaigns ought to be prioritized on the global health and public policy agendas as a major public health issue. Routine screening for suicidal ideation by health care professionals providing care should identify and assess suicide risk among populations. According to the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), risk factors of suicide include mental illness, substance use diagnoses, trauma or conflict, loss, family history of suicide, and previous suicide attempts [2].

Effectively implementing suicide prevention strategies at the populational, sub-populational and individual level requires ensuring patients’ lethal means are restricted, reduced, and that all accesss to weapons of self-harm are removed from the nearby environments. Healthcare providers should keep up to date with new developments, research, and technologies screening for suicidal ideation, allowing them to effectively serve patients beyond their clinics’ walls. Key to prevention are strong physician patient relationships that help ensure care transitions allow for physicians to act as supportive contacts reaching out with calls, texts, letters and visits to their patients particularly when services are interrupted. With access to technology the role of psychiatrists, and psychologists may continue uninterrupted as telemedicine serves as an effective platform providing patients with access to care, even during lockdowns. Besides these objectives, greater awareness and education into the community means encouraging the responsible portrayal of suicide in mainstream media. A sensitive issue of this magnitude ought to be communicated responsibly placing special attention to not trigger susceptible individuals. With school based interventions, professionals may act sooner before worsened prognosis’ effectively ensuring that access to peer support services is available. 

Suicide prevention is a responsibility of healthcare systems, medical professionals and communities. All countries must stand in solidarity and unify in collaboration to battle this common threat as preventing the tragic loss of life to suicide is of utmost importance. 

References & Further Reading

  1. In Health and Behavioral Healthcare. (n.d.). Retrieved September 14, 2020, from http://zerosuicide.edc.org/toolkit/treat/interventions-suicide-risk 
  2. Psychiatry Online: DSM Library. (n.d.). Retrieved September 15, 2020, from https://dsm.psychiatryonline.org/doi/book/10.1176/appi.books.9780890425596 
Cite this article as: Leah Sarah Peer, Canada, "Suicide – An Emergency Priority of Public Health Care," in International Emergency Medicine Education Project, October 19, 2020, https://iem-student.org/2020/10/19/suicide-an-emergency-priority-of-public-health-care/, date accessed: December 11, 2023

Evidence-based Approach: Introduction

~ Elif Dilek Cakal, Turkey ~ Leave a comment

Acquiring solid history-taking and physical examination skills, the ability to use and interpret them in the right way are essential for physicians.

The literature shows the physical examination, in general, is considered in decline while the use of laboratory and imaging testing has markedly increased (1-3). Indeed, physicians tend to over-rely on the test results, instead of history and physical examination findings. A reason for this trend may be physicians’ lack of knowledge or confidence (4,5). However, not every institution has the optimal resources and even if they have, extensively testing every patient for every disease possible is not cost-effective or free of complications (5). Therefore, acquiring solid history-taking and physical examination skills, the ability to use and interpret them in the right way are still essential for physicians.

Learning and performing history-taking and physical examination techniques is one thing, applying the findings to reach a diagnosis is another (6). Early learners tend to focus on mastering the skills itself so much that often they may fail to notice how to utilize it, its strengths and weaknesses. iEM Education Project’s new series “Evidence-based Approach to History-taking and Physical Examination” aims to support this learning gap.

In a way, evidence-based history-taking and physical examination challenge traditional habits in an attempt to curate them; gives us the information needed to abandon the invalid techniques and nourish the beneficial ones. However, interpreting the findings relies on understanding the evidence. Therefore, before analyzing each disease from the perspective of evidence-based diagnostic skills, we need to review the biostatistical terms such as pre-test probability, sensitivity and specificity, positive and negative likelihood ratios (LR).

Below is a simple reminder about how to interpret these values. You may refer to the links provided to reach more information.

Pre-test Probability

Pre-test probability is the probability of the disease before implementing any results (7,8). In other words, it is how likely the physician thinks a patient with a chief complaint may have a specific condition. There are three main ways to estimate pretest probability; first, prevalence studies; second, validated clinical prediction rules; and third, physicians’ gestalt based on their own clinical experience (9).

Sensitivity

Sensitivity is a feature (symptom, sign or test) with a high sensitivity is positive more frequently in patients compared to healthy population and selects patients accurately when it is positive (positivity in disease) (7). Therefore, when a highly sensitive feature is absent, the probability of the disease decreases. (SnNout = a Sensitive test, when Negative, rules out disease) (7).

Specificity

Specificity is a feature (symptom, sign or test) with a high specificity is negative more frequently in the health population compared to patients and selects healthy people accurately when it is negative (negativity in health) (7). Therefore, when a highly specific test is positive, the probability of the disease increases. (SpPin = a Specific test, when Positive, rules in disease) (7).

Positive Likelihood Ratio (LR+)

LR+ describes how the probability of a disease changes when a feature (symptom, sign or test) is present (10).

      • If LR+ > 1, the presence of the feature, increases the probability of the disease. The bigger the LR+, the more strongly it favors the diagnosis.
      • If LR+ = 1, the presence of the feature does not change the probability. Therefore, it does not have diagnostic value. 
      • If LR+ = 0-1, the presence of the feature decreases the probability of the disease. The smaller the LR+, the more strongly it opposes the diagnosis (10).

Negative Likelihood Ratio (LR-)

LR- describes how the probability of a disease changes when a feature (symptom, sign or test) is absent (10).

      • If LR- > 1, the absence of the feature, increases the probability of the disease. The bigger the LR-, the more strongly it favors the diagnosis.
      • If LR- = 1, the absence of the feature does not change the probability. Therefore, it does not have diagnostic value.
      • If L- = 0-1, the absence of the feature decreases the probability of the disease. The smaller the LR-, the more strongly it opposes the diagnosis (10).

How to combine all?

In the traditional sense, the pretest probability is used to mean the prevalence of a disease before ordering a test (8). Basically, it is another way of saying physicians used to combine symptoms and signs intuitively, based on their experience to reach a pretest probability. However, evidence-based medicine encourages the physicians and the literature to reflect on the practice, break it into pieces and review the individual and collective value of each part. Accordingly, each individual feature from history or examination can be considered “tests.” (8)

You may think reviewing the value of each feature from the history and physical examination is mentally exhausting. Validated clinical prediction rules are here to help! Similar to the traditional sense, but in an evidence-based and standardized way, the validated clinical prediction rules combine some elements to reach a more straightforward calculation of pretest (9).

Overall, interpreting the findings is as important as performing the skill itself. Interpretation requires biostatistical knowledge as much as clinical ability. When applied analytically, history-taking and physical examination can safely accelerate the diagnostic process and limit overtesting (5).

References and Further Reading

  1. Smith-Bindman, R., Miglioretti, D. L., & Larson, E. B. (2008). Rising use of diagnostic medical imaging in a large integrated health system. Health Affairs, 27(6), 1491-1502.
  2. O’Sullivan, J. W., Stevens, S., Hobbs, F. R., Salisbury, C., Little, P., Goldacre, B., … & Heneghan, C. (2018). Temporal trends in use of tests in UK primary care, 2000-15: retrospective analysis of 250 million tests. British Medical Journal, 363, k4666.
  3.  Bergl, P., Farnan, J. M., & Chan, E. (2015). Moving toward cost-effectiveness in physical examination. The American Journal of Medicine, 128(2), 109-110.
  4. Cook, C. (2010). The lost art of the clinical examination: an overemphasis on clinical special tests. The Journal of Manual & Manipulative Therapy, 18(1), 3.
  5. Greenberg, J., & Green, J. B. (2014). Over-testing: why more is not better. The American Journal of Medicine, 127(5), 362-363.
  6. Chi, J., Artandi, M., Kugler, J., Ozdalga, E., Hosamani, P., Koehler, E., … & Verghese, A. (2016). The five-minute moment. The American Journal of Medicine, 129(8), 792-795.
  7. McGee, S. (2018). Evidence-based Physical Diagnosis (4th Ed., Kindle Ed.). Philadelphia: Elsevier.
  8. Parikh, R., Parikh, S., Arun, E., & Thomas, R. (2009). Likelihood ratios: clinical application in day-to-day practice. Indian Journal of Ophthalmology, 57(3), 217.
  9. Shaneyfelt, T. (2012). Diagnostic Process. [Online Lecture]. Retrieved April 25, 2019 from https://www.youtube.com/watch?v=6qgnrXELoo4.
  10. McGee, S. (2002). Simplifying likelihood ratios. Journal of General Internal Medicine, 17(8), 647-650.
Cite this article as: Elif Dilek Cakal, Turkey, "Evidence-based Approach: Introduction," in International Emergency Medicine Education Project, April 29, 2019, https://iem-student.org/2019/04/29/evidence-based-medicine/, date accessed: December 11, 2023