Question Of The Day #55

question of the day
738.2 - STEMI
Which of the following is the most likely cause for this patient’s condition?  

This patient presents with chest pressure at rest and an anterior ST segment elevation myocardial infraction (STEMI) seen on 12-lead EKG.  This patient should be given aspirin, IV fluids to increase the preload status, and receive immediate coronary reperfusion therapy.  This patient’s hypotension is likely due to infarction of the left ventricle causing poor cardiac output (Choice D).  This is known as cardiogenic shock.  The patient has been vomiting, but the acute onset of symptoms and STEMI on EKG make poor cardiac output (Choice D) more likely than hypovolemia (Choice A) as the cause for the patient’s condition.  Systemic infection (Choice B) and pulmonary embolism (Choice C) are also less likely given the clinical information in the case and the STEMI on EKG.  The best answer is Choice D.  Please see the chart below for further detailing of the different types of shock.   

References

Cite this article as: Joseph Ciano, USA, "Question Of The Day #55," in International Emergency Medicine Education Project, September 17, 2021, https://iem-student.org/2021/09/17/question-of-the-day-55/, date accessed: September 24, 2021

Question Of The Day #54

question of the day
Which of the following is the most likely cause for this patient’s condition?

This patient sustained significant blunt trauma to the chest, presents to the Emergency Department with hypotension, tachycardia, a large chest ecchymosis, and palpable sternal crepitus.  The ultrasound image provided shows a subxiphoid view of the heart with a large pericardial effusion.  In the setting of trauma, this should be assumed to be a hemopericardium.  This patient has cardiac tamponade, which is considered a type of obstructive shock (Choice C).  Treatment includes IV hydration to increase preload, bedside pericardiocentesis, and ultimately, a surgical cardiac window performed by cardiothoracic surgery.  The other shock types (Choices A, B, D) do not describe this patient’s presentation.  Please see the chart below for further description of the different shock types and therapies.

 

References

Cite this article as: Joseph Ciano, USA, "Question Of The Day #54," in International Emergency Medicine Education Project, September 10, 2021, https://iem-student.org/2021/09/10/question-of-the-day-54/, date accessed: September 24, 2021

Question Of The Day #53

question of the day

Which of the following is the most likely cause for this patient’s condition?

This patient endured a high-speed motor vehicle accident, arrives with hypotension and bradycardia, and has a C6 vertebral body fracture on imaging.  These details support a diagnosis of neurogenic shock, a type of distributive shock.

Shock is an emergency medical state characterized by cardiovascular or circulatory failure.  Shock prevents peripheral tissues from receiving adequate perfusion, resulting in organ dysfunction and failure.  Shock can be categorized as hypovolemic, distributive, obstructive, or cardiogenic.  The different categories of shock are defined by their underlying cause (i.e., sepsis, hemorrhage, pulmonary embolism, etc.) and their hemodynamics which sometimes overlap.  The diagnosis of shock is largely clinical and supported by the history, vital signs, and physical exam.  Additional studies, such as laboratory investigations, bedside ultrasound, and imaging tests help narrow down the type of shock, potential triggers, and guide management.  The chart below details the categories of shock, each category’s hemodynamics, potential causes, and treatments.  

Neurogenic shock is caused by spinal cord damage above the T6 level.  Unlike other types of shock, neurogenic shock is characterized by hypotension and bradycardia (not tachycardia).  These vital sign abnormalities are caused by damage to sympathetic nervous system (Choice C).  Neurogenic shock has decreased systemic vascular resistance (warm extremities), not increased systemic vascular resistance (cool extremities) (Choice A).  Occult hemorrhage (Choice B) is always a concern in a trauma patient.  However, this would present with findings of hypovolemic/hemorrhagic shock (tachycardia, hypotension, cool extremities).  Tension pneumothorax (Choice D) is also unlikely as the patient has clear bilateral lung sounds on exam.  The best answer is Choice C.

References

Cite this article as: Joseph Ciano, USA, "Question Of The Day #53," in International Emergency Medicine Education Project, September 3, 2021, https://iem-student.org/2021/09/03/question-of-the-day-53/, date accessed: September 24, 2021

Question Of The Day #52

question of the day

Which of the following is the most appropriate next step in management for this patient’s condition?

This patient has anaphylactic shock, which falls under the category of distributive shock.  Anaphylactic shock is an acutely life-threatening type of allergic reaction that if left untreated, can progress to airway edema, asphyxiation, and death.  Exposure to a known or unknown allergen is the trigger for anaphylaxis.  Diagnosis of this condition requires the below criteria to be met:

  1. Acute onset of skin or mucosal changes (i.e., urticaria, tongue or lip swelling) AND hypotension or respiratory compromise (i.e., wheezing).

OR

  1. Dysfunction of two or more body systems after exposure to a presumed allergen:
    1. Skin/mucosa (i.e., urticaria, swelling of tongue or lips)
    2. Pulmonary (i.e., wheezing)
    3. Cardiovascular (i.e., hypotension)
    4. Gastrointestinal (i.e., vomiting or diarrhea)
    5. End-organ dysfunction

Management of anaphylaxis requires proper evaluation of the patient’s airway, respiratory status, and hemodynamics (“ABCs”).  Mainstays of therapy are intramuscular epinephrine (0.3mg in adults) and IV hydration.  Administration of epinephrine is a time sensitive and life-saving intervention.  Antihistamines, nebulized albuterol or salbutamol, and steroids are additional therapies that are commonly given.  Steroids are thought to prevent recurrent anaphylactic reactions, however, there is little data to support this.  Patients are typically monitored for 4-6 hours after administration of epinephrine to observe for changes in clinical status or the need for additional doses of epinephrine.  Patients who remain stable or improve after this observation period are able to be discharged home with a prescription for an epinephrine injector in the event of future anaphylaxis episodes. 

Intravenous normal saline (Choice A) and diphenhydramine (Choice B) are important therapies to administer in this patient, but intramuscular epinephrine (Choice C) is the most time-sensitive initial therapy to administer.  Without treatment, airway edema may progress and require endotracheal intubation (Choice D).  The patient’s clear voice and lack of stridor indicate that the patient does not need immediate intubation. 

Correct Answer: C

References

Cite this article as: Joseph Ciano, USA, "Question Of The Day #52," in International Emergency Medicine Education Project, August 27, 2021, https://iem-student.org/2021/08/27/question-of-the-day-52/, date accessed: September 24, 2021

Cognitive load theory and its applications in emergency medicine education

Throughout my medical education thus far, I have been very drawn to simulation and cognitive load research related to emergency medicine. This has provided me with an appreciation for the applications of cognitive load theory to diverse areas within the specialty, including medical education.

What is cognitive load?

The cognitive load theory was developed in the late 1980s and explores the ways in which the amount of mental effort affects your working memory, and subsequently, learning (1). Specifically, learning involves processing sensory stimuli through various forms of memory, until the stimuli are encoded into your long-term memory. When the working memory capacity is surpassed, the ability to acquire or learn new information can become limited and may lead to poor performance or errors. Since the development of this theory, research in this area has been expanding to enhance instructional design to optimize learning.

Fig. 1. The basic structure of memory, extending from sensory input to encoding of long-term memory (obtained from Mancinetti et al. (2019)) - (2)

Objective and subjective measures of cognitive load

Global collaborative and independent research initiatives have identified an array of objective physiologic measures (e.g. pupillometry, heart rate, galvanic skin response and EEG parameters), subjective psychometric measures (e.g. Paas, NASA Task Load Index (NASA-TLX)) and secondary task measures that are indicative of an individual’s cognitive load (3). Current research has been investigating the validity of these physiologic metrics beyond a controlled laboratory setting, in order to determine accurate measures that can be applied within dynamic and real-life settings. This can potentially allow us to monitor learners’ cognitive load in real-time and adjust teaching strategies accordingly to optimize learning.

Fig. 2. NASA-TLX cognitive load scale (obtained from Shively, J, NASA-Ames Research Center (2016)) and the Paas rating scale (obtained from Paas et al. (2008)) - (4-5)

Applications of cognitive load theory to emergency medicine education

A paper by Croskerry (2014) highlighted various factors that can influence cognitive load in the emergency department setting and lead to clinical errors, including overcrowding, and fatigue and circadian dyssynchronization secondary to shiftwork (6). Of relevance, a previous post on emDocs explored numerous strategies for emergency providers to mitigate some of this cognitive load (link here: http://www.emdocs.net/cognitiveload/). Furthermore, experienced emergency physicians have developed strategies to better manage their cognitive resources, effectively reducing their cognitive load relative to trainees in similar clinical scenarios. Therefore, there are many ways in which cognitive load theory can be implicated in emergency medicine and used to not only enhance the functional and spatial design of the emergency department, but to also optimize simulation training and other areas of learning for emergency medicine trainees. For example, Johannessen et al. (2019) evaluated the association between physiologic measures and the Paas scale in trauma team leaders using wearable technology during the resuscitation response, in order to better understand cognitive load expression in emergency physicians during traumas (7). Additionally, another study used galvanic skin response, heart rate and a modified Paas scale to assess the “Beat the Stress Fool” protocol in reducing mental effort during clinical simulation (7). Fraser et al. (2018) investigated the link between the cognitive load theory and debriefing simulations. Specifically, they evaluated whether the categorization of mental loads during debriefing can improve learning of this vital and complex skill, and they additionally discussed strategies to alleviate some of the associated cognitive load (8).  

Overall, cognitive load is an exciting and evolving area in research and has many diverse applications in emergency medicine and medical education as a whole. 

References and Further Reading

  1. Sweller, J. (1988). Cognitive Load During Problem Solving: Effects on Learning. Cognitive Science, 12, 257-285.
  2. Mancinetti, M., Guttormsen, S., Berendonk, C. (2019). Cognitive load in internal medicine: What every clinical teacher should know about cognitive load theory. European Journal of Internal Medicine, 60, 4-8. 
  3. Paas, Fred, et al. (2003). Cognitive Load Measurement as a Means to Advance Cognitive Load Theory. Educational Psychologist, 38(1), 63–71.
  4. Shively, J, NASA-Ames Research Center. (2016). Workload Measurement in Human Autonomy Teaming: How and Why? National Aeronautics and Space Administration. Accessed May 2020 at https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20160008388.pdf
  5. Paas, F., Ayres, P., Pachman, M. (2008). Assessment of cognitive load in multimedia learning therory, methods and applications. Recent Innovations in Educational Technology that Facilitate Student Learning, Chapter 2, pg.11-35. 
  6. Croskerry, P. (2014). ED cognition: any decision by anyone at any time. CJEM, 16(1), 13-9.
  7. Johannessen, E., Szulewski, A., Radulovic, N., Gilic, F., Braund, H., Wu, K., White, M., Rodenburg, D., Howes, D., Davies, C. (2019). Measuring cognitive load in a clinical setting: Medical learning and practice. (M.A.Sc thesis), Queen’s University, Kingston, Canada. 
  8. Fraser, K.L. et al. (2018). Cognitive Load Theory for debriefing simulations: implications for faculty development. Advances in Simulation, 3, 1-8.
Cite this article as: Nada Radulovic, Canada, "Cognitive load theory and its applications in emergency medicine education," in International Emergency Medicine Education Project, August 23, 2021, https://iem-student.org/2021/08/23/cognitive-load-theory/, date accessed: September 24, 2021

Question Of The Day #51

question of the day
Which of the following is the most likely cause for the patient’s condition?

This patient is in a shock state caused by left-sided pyelonephritis.

Shock is an emergency medical state characterized by cardiovascular or circulatory failure.  Shock prevents peripheral tissues from receiving adequate perfusion, resulting in organ dysfunction and failure.  Shock can be categorized as hypovolemic, distributive, obstructive, or cardiogenic.  The different categories of shock are defined by their underlying cause (i.e., sepsis, hemorrhage, pulmonary embolism, etc.) and their hemodynamics which sometimes overlap.  The diagnosis of shock is largely clinical and supported by the history, vital signs, and physical exam.  Additional studies, such as laboratory investigations, bedside ultrasound, and imaging tests help narrow down the type of shock, potential triggers, and guide management.  The chart below details the categories of shock, each category’s hemodynamics, potential causes, and treatments.   

The patient’s signs, symptoms, physical exam, and urine studies point towards an infectious etiology.  This patient is in septic shock, which is considered a type of distributive shock (Choice B).  Hypovolemic shock (Choice A), obstructive shock (Choice C), and cardiogenic shock (Choice D) are caused by other conditions reflected in the above table. 

References

Cite this article as: Joseph Ciano, USA, "Question Of The Day #51," in International Emergency Medicine Education Project, August 20, 2021, https://iem-student.org/2021/08/20/question-of-the-day-51/, date accessed: September 24, 2021

Question Of The Day #50

question of the day

Which of the following is the most appropriate next step in management for this patient’s condition?

This patient presents to the Emergency Department with altered mental status.  This presenting symptom can be due to a large variety of etiologies, including hypoglycemia, sepsis, toxic ingestions, electrolyte abnormalities, stroke, and more.  The management and evaluation of a patient with altered mental status depends on the primary assessment of the patient (“ABCs”, or Airway, Breathing, Circulation) to identify any acute life-threatening conditions that need to be managed emergently, the history, and the physical examination.  One mnemonic that may help in remembering the many causes of altered mental status is “AEIOUTIPS”.  The table below outlines this mnemonic.

ALTERED MENTAL STATUS

This patient arrives hyperthermic, tachycardic in atrial fibrillation, diaphoretic, and altered with psychotic behavior.  Thyroid storm, the most severe manifestation of hyperthyroidism, should always be on the differential diagnosis in patients with fever and altered mental status.  Other considerations are sepsis, sympathomimetic overdose, anticholinergic overdose, serotonin syndrome, and pheochromocytoma. 

This patient has thyroid storm, a life-threatening endocrine emergency that requires prompt recognition and treatment.  Symptoms of thyroid storm include altered mental status, psychosis, seizures, coma, tachycardia, atrial fibrillation, high-output heart failure, dyspnea, vomiting, diarrhea, weight loss, and anterior neck enlargement.  Severe hyperthyroidism should have a low-undetectable TSH level with elevated T3/T4 levels, but in acute illness these levels may be unreliable.  For this reason, the diagnosis and treatment of thyroid storm should be based on clinical grounds.

An anticholinergic toxidrome can appear similar to this patient with tachycardia, hypertension, agitation, and altered mental status.  A key differentiating factor is diaphoresis.  Patients with anticholinergic ingestions should have dry skin, not wet skin. The treatment for anticholinergic toxicity is benzodiazepines and IV physostigmine (Choice A) if symptoms are unresponsive to benzodiazepines.  Physostigmine is not the best next step in this scenario. 

Treatment of thyroid storm is algorithmic.  First, beta blockade (Choice C) should be given to control the heart rate and block T4 to T3 conversion, next anti-thyroid medications (Methimazole or Propylthiouracil (Choice D)) should be given to block thyroid hormone synthesis, and lastly corticosteroids and inorganic iodine (Choice B) can be given to block release of stored thyroid hormone.  The best next step in managing this patient with thyroid storm is administration of IV Propranolol (Choice C).  Propranolol helps manage the tachycardia, systemic symptoms, and also inhibits conversion of T4 to T3. 

 Correct Answer: C

References

Cite this article as: Joseph Ciano, USA, "Question Of The Day #50," in International Emergency Medicine Education Project, August 13, 2021, https://iem-student.org/2021/08/13/question-of-the-day-50/, date accessed: September 24, 2021

Defibrillator: Clear!

Defibrillator clear

So, this is your first day at your internship rotation in the Emergency Department. You see some movement in the resuscitation room, and someone shouts: CODE!

Then, you approach the team, excited to learn and help with cardiopulmonary resuscitation (CPR). The attending physician looks at you and asks: Do you know how to use the defibrillator?

What would your answer be?

Knowing the main functions of the defibrillator is essential but not enough; you need to get used to the model in your hospital to be able to help safely with an emergency.

Defibrillators are devices used to apply electrical energy manually or automatically. Their use is indicated for electrical cardioversion, defibrillation or as a transcutaneous pacemaker.

Later that day, another patient presents with unstable atrial fibrillation (AFib).

The attending suggests cardioverting the patient. Do you know how to prepare the defibrillator?

Defibrillation versus cardioversion

Both defibrillation and cardioversion are techniques in which an electrical current is applied to the patient, through a defibrillator, to reverse a cardiac arrhythmia.

Defibrillation

Defibrillation is a non-synchronized electrical discharge applied to the chest, which aims to depolarize all myocardial muscle fibres, thus literally restarting the heart, allowing the sinoatrial node to resume the generation and control of the heart rhythm, and reversing the severe arrhythmias. It is indicated for pulseless ventricular tachycardia and ventricular fibrillation during CPR.

Electrical Cardioversion

Electrical cardioversion is the application of shock in a synchronized way to ensure the electric discharge is released in the R wave, that is, in the refractory period because accidental delivery of the shock during the vulnerable period, that is, the T wave, can trigger VF. It is reserved for severe arrhythmias in unstable patients with a pulse. It can usually be an elective procedure.

Special Situations

Digital Intoxication

Digital intoxication can present with any type of tachyarrhythmia or bradyarrhythmia. Cardioversion in this situation is a relative contraindication, as digital makes the heart sensitive to electrical stimulation. Before considering cardioversion, correct all electrolyte imbalances, otherwise, the cardioversion can degenerate the rhythm to a VF.

Pacemaker / Implantable cardioverter-defibrillator (ICD)

Cardioversion can be performed, but with care. The inadequate technique can damage the generator, the conductive system, or the heart muscle, leading to dysfunction of the device. The blades must be positioned at least 12 cm away from the generator, preferably in the anteroposterior position. The lowest possible electrical charge must be used.

Pregnancy

Cardioversion can be used safely during pregnancy. The fetal beat should be monitored throughout the procedure.

Things To Consider

Keep your devices tested!

Working in the ED is not easy. This is the place where organization and preparation should be routine. Constant checking of materials and operation of the equipment must be the rule because the smallest detail can cause a difference in saving a life.

During adversity, it is necessary to remain calm, trying to not affect the reasoning and disposition of the team. It is an arduous job, it takes practice and a lot of effort. Errors can only be corrected after they are recognized and must have the right time to be exposed. It happens.

There is no time for despair, yelling and stress when it comes to CPR.

No conductive gel, what can we do?

The main guidelines regarding the use of the conductive gel used in the defibrillator paddles are:

  • Using the proper gel for this purpose is essential. The gel is an electrically conductive material that decreases the resistance to the flow of electric current between the paddle and the chest wall. The absence of conductive material can lead to the production of an arc that causes burns in the patient and the risk of explosion if there is an oxygen source very close, among others.
  • Avoid the use of gauze soaked in saline solution, as the excess serum can cause burns on the patient’s skin, but it is a reasonable option, in an emergency
  • Do not use the ultrasound gel
  • The preference is to use adhesive paddles that already come with their own conductive gel (but this is rare in Brazil).

Location recommended by Advanced Cardiac Life Support (ACLS)

Antero-lateral

One paddle is placed on the right side of the sternum, right below the clavicle and the other laterally where the cardiac appendix would be in the anterior or medial axillary line (V5-V6).

Adhesive paddles can also be placed in an anteroposterior position: The anterior one is placed in the cardiac appendage or precordial region, and the posterior one is placed on the back in the right or left infrascapular region.

During the shock, the provider must ensure that no one is in contact with the patient. A force of approximately 8k must be used to increase the contact of the paddles with the chest. Do not allow a continuous flow of oxygen over the patient’s chest to avoid accidents with sparks.

Complications

  • Electric arc (when electricity travels through the air between the electrodes and can cause explosive noises, burns and impair current delivery)
  • Electrical injuries in spectators
  • Risk of explosion if there is a continuous flow of oxygen during the shock
  • Burning of the skin by repeated shocks
  • Myocardial injury and post-defibrillation arrhythmias and myocardial stunning
  • Skeletal muscle injury
  • Fracture of thoracic vertebrae

References and Further Reading

  1. Sunde, K., Jacobs, I., Deakin, C. D., Hazinski, M. F., Kerber, R. E., Koster, R. W., Morrison, L. J., Nolan, J. P., Sayre, M. R., & Defibrillation Chapter Collaborators (2010). Part 6: Defibrillation: 2010 international consensus on cardiopulmonary resuscitation and emergency cardiovascular care science with treatment recommendations. Resuscitation81 Suppl 1, e71–e85. https://doi.org/10.1016/j.resuscitation.2010.08.025
  2. Panchal, A. R., Bartos, J. A., Cabañas, J. G., Donnino, M. W., Drennan, I. R., Hirsch, K. G., Kudenchuk, P. J., Kurz, M. C., Lavonas, E. J., Morley, P. T., O’Neil, B. J., Peberdy, M. A., Rittenberger, J. C., Rodriguez, A. J., Sawyer, K. N., Berg, K. M., & Adult Basic and Advanced Life Support Writing Group (2020). Part 3: Adult Basic and Advanced Life Support: 2020 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation142(16_suppl_2), S366–S468. https://doi.org/10.1161/CIR.0000000000000916
  3. Ionmhain, U. N. (2020). Defibrillation Basics. Life in The Fastlane. Retrieved April 26, 2020, from https://litfl.com/defibrillation-basics/
  4. Paradis, N. A., Halperin, H. R., Kern, K. B., Wenzel, V., & Chamberlain, D. A. (Eds.). (2007). Cardiac arrest: the science and practice of resuscitation medicine. Cambridge University Press.
  5. Nickson, C. (2020). Defibrillation Pads and Paddles. Life in The Fastlane. Retrieved April 26, 2020, from https://litfl.com/defibrillation-pads-and-paddles/
Cite this article as: Jule Santos, Brasil, "Defibrillator: Clear!," in International Emergency Medicine Education Project, August 9, 2021, https://iem-student.org/2021/08/09/defibrillator-clear/, date accessed: September 24, 2021

Question Of The Day #49

question of the day
Which of the following is the most likely cause of this patient’s condition?

This patient presents to the Emergency Department with altered mental status.  This presenting symptom can be due to a large variety of etiologies, including hypoglycemia, sepsis, toxic ingestions, electrolyte abnormalities, stroke, and more.  The management and evaluation of a patient with altered mental status depends on the primary assessment of the patient (“ABCs”, or Airway, Breathing, Circulation) to identify any acute life-threatening conditions that need to be managed emergently, the history, and the physical examination.  One mnemonic that may help in remembering the many causes of altered mental status is “AEIOUTIPS”.  The table below outlines this mnemonic.

ALTERED MENTAL STATUS

Hyperthermia (or hypothermia) can cause altered mental status.  This patient arrives with altered mental status, severe hyperthermia, tachycardia, tachypnea, and hypotension.  The history of the patient running outside for exercise should raise concern for hyperthermia related to excess heat production due to overexertion.  This should narrow the differential diagnoses to heat exhaustion (Choice B) and heat stroke (Choice C).  Both heat exhaustion and heat stroke are marked by hyperthermia with temperatures often over 40ᵒC. Additional symptoms include weakness, nausea, vomiting, myalgias, syncope, and headache.  The differentiating factor between heat exhaustion and heat stroke is altered mental status and sweating.  Patients with heat exhaustion lack altered mental status and should still be able to thermoregulate through sweating.  On the contrary, heat stroke patients are more severely ill as they have altered mental status and can no longer thermoregulate with sweating.  The treatment in both conditions should be early and aggressive cooling measures.  This includes full body immersion in an ice bath, removal of clothes, and cold IV fluids.  Internal cooling with gastric, bladder, pleural, or peritoneal lavage with cold fluids can be done on more sick patients.  Antipyretic medications, like NSAIDs and paracetamol, have no benefit in patients with severe hyperthermia.  Evaluation for rhabdomyolysis, kidney failure, liver failure, sepsis, or other organ dysfunction should also be a part of the evaluation of hyperthermic patients.

Sympathomimetic toxicity (Choice A) is possible, but less likely as the skin is dry and the history of exercise outdoors.  Sympathomimetic toxicity manifests as diaphoresis, tachycardia, hypertension, hyperthermia, and sometimes altered mental status.  Thyroid storm (Choice D) is another possibility.  This diagnosis can also present with similar vital signs, hyperthermia, and altered mental status.  Again, the history of outdoor exercise should point more towards heat exhaustion vs heat stroke.

The diagnosis of this patient is heat stroke (Choice C) as he has altered mental status and lacks wet skin.

Correct Answer: C

References

Cite this article as: Joseph Ciano, USA, "Question Of The Day #49," in International Emergency Medicine Education Project, August 6, 2021, https://iem-student.org/2021/08/06/question-of-the-day-49/, date accessed: September 24, 2021

Question Of The Day #48

question of the day

Which of the following is the most likely cause of this patient’s condition?

This patient presents to the Emergency Department with altered mental status.  This presenting symptom can be due to a large variety of etiologies, including hypoglycemia, sepsis, toxic ingestions, electrolyte abnormalities, stroke, and more.  The management and evaluation of a patient with altered mental status depends on the primary assessment of the patient (“ABCs”, or Airway, Breathing, Circulation) to identify any acute life-threatening conditions that need to be managed emergently, the history, and the physical examination.  One mnemonic that may help in remembering the many causes of altered mental status is “AEIOUTIPS”.  The table below outlines this mnemonic.

ALTERED MENTAL STATUS

The first step in managing this patient should be to treat the hypoxia with supplemental oxygen.  Prolonged hypoxia is dangerous and if left untreated, can cause brain damage.  Hypoxia can cause altered mental status, however, when this patient’s hypoxia is resolved, she remains somnolent and altered.  This should raise concern over an alternative etiology for the patient’s condition.      

The arterial blood gas demonstrates a low pH (acidosis), normal paO2, elevated paCO2 (hypercarbia), and a normal HCO3 (no metabolic compensation for acidosis).  The final interpretation of the ABG would be an acute respiratory acidosis without metabolic compensation.  Acute elevations of pCO2 can manifest as somnolence and altered mental status as seen in this patient.  This is known as hypercarbic or hypercapnic respiratory failure (Choice A).  This condition is caused by the inability to exhale CO2.  Risk factors include obstructive lung diseases (i.e., COPD), obesity, and obstructive sleep apnea.  Treatment involves treatment of hypoxia with supplemental oxygen, non-invasive positive pressure ventilation (i.e., BIPAP, CPAP, High Flow Nasal Cannula), and treatment of the underlying cause.

The patient’s arterial blood gas does not show hypoxic respiratory failure (Choice B).  Since treatment of the patient’s hypoxia does not improve the patient’s mental status, hypercarbic respiratory failure is more likely the underlying cause of the patient’s condition.  Opioid overdose (Choice C) can cause a similar ABG and patient presentation.  The normal size pupils and absent history of drug abuse makes this diagnosis less likely. Sepsis (Choice D) can trigger changes in mental status and cause respiratory failure, however, the absence of infectious symptoms and the presence of obesity and COPD support hypercarbic respiratory failure as the more likely underlying cause. 

Correct Answer: A

References

Cite this article as: Joseph Ciano, USA, "Question Of The Day #48," in International Emergency Medicine Education Project, July 30, 2021, https://iem-student.org/2021/07/30/question-of-the-day-48/, date accessed: September 24, 2021

Question Of The Day #47

question of the day

Which of the following is the most appropriate next step in management for this patient’s condition?

This patient presents to the Emergency Department with altered mental status.  This presenting symptom can be due to a large variety of etiologies, including hypoglycemia, sepsis, toxic ingestions, electrolyte abnormalities, stroke, and more.  The management and evaluation of a patient with altered mental status depends on the primary assessment of the patient (“ABCs”, or Airway, Breathing, Circulation) to identify any acute life-threatening conditions that need to be managed emergently, the history, and the physical examination.  One mnemonic that may help in remembering the many causes of altered mental status is “AEIOUTIPS”.  The table below outlines this mnemonic.

ALTERED MENTAL STATUS

The initial approach to all Emergency Department patients, especially those with abnormal vital signs, should include a primary survey (“ABCs”, or Airway, Breathing, Circulation).  This patient is breathing independently but at a significantly reduced rate and is hypoxic.  Hypoxia should prompt the administration of supplemental oxygen to the patient and reassessment of the SpO2.  The patient’s reduced respiratory rate, lethargy, and bilateral miosis (constricted pupils) should strongly hint at the possibility of opioid overdose.  Although the patient is lethargic and hypoxic, establishing a definitive airway (endotracheal intubation) should be avoided until after the antidote to opioid overdose is administered.  Naloxone is a mu-opioid receptor antagonist and functions as the antidote to opioid overdose.

 

Administration of 1000mL of 0.9% NaCl (Choice A) is unlikely to fix the patient’s clinical condition.  The patient needs naloxone to improve respiratory status.  25g of IV dextrose (Choice B) would be helpful if this patient’s altered mental status was from hypoglycemia.  A normal glucose level is provided in the question stem.  100mg of IV thiamine (Choice D) may be helpful in the case of Wernicke-Korsakoff Syndrome, a state of thiamine deficiency often associated with malnutrition and alcohol abuse.  Wernicke-Korsakoff Syndrome presents with vision disturbances, ataxia, and confusion.  Typically, this syndrome does not present with severe lethargy or depressed mental status as is seen in this patient.

The best next step in management is 1mg of IV naloxone (Choice C).  If given appropriately, naloxone can prevent the need for intubation.  Naloxone has a very short onset to action (~1min).  If suspicion for opioid overdose is high and there is an inadequate respiratory response after a single naloxone dose, repeat doses of naloxone are appropriate.  Naloxone can be administered in repeat boluses every 3-minutes to a total dose of 10mg IV.  Patients who respond appropriately to naloxone should be observed for recurrent respiratory depression as naloxone is cleared.  Need for repeat doses of naloxone indicates the need for a continuous naloxone infusion and hospital admission.  The typical infusion dose is 2/3 the “wake-up” dose given over 1 hour as a continuous infusion.  For example, if the patient responded to 1mg IV initially, the continuous infusion dose would be 0.6mg/hour of IV naloxone.

Correct Answer: C

References

Cite this article as: Joseph Ciano, USA, "Question Of The Day #47," in International Emergency Medicine Education Project, July 23, 2021, https://iem-student.org/2021/07/23/question-of-the-day-47/, date accessed: September 24, 2021

Question Of The Day #46

question of the day

Which of the following is the most appropriate next step in management for this patient’s condition?

This patient presents to the Emergency Department with altered mental status.  This presenting symptom can be due to a large variety of etiologies, including hypoglycemia, sepsis, toxic ingestions, electrolyte abnormalities, stroke, and more.  The management and evaluation of a patient with altered mental status depends on the primary assessment of the patient (“ABCs”, or Airway, Breathing, Circulation) to identify any acute life-threatening conditions that need to be managed emergently, the history, and the physical examination.  One mnemonic that may help in remembering the many causes of altered mental status is “AEIOUTIPS”.  The table below outlines this mnemonic.

ALTERED MENTAL STATUS

The serum chemistry results provided show elevated BUN and Creatinine with a BUN/Cr ratio of 21.3.  A BUN/Cr ratio greater than 20 indicates decreased perfusion to the kidneys, also known as pre-renal azotemia, which can indicate dehydration, hypovolemia, or shock.  The serum chemistry also shows a severely low sodium level.  Hyponatremia can present with a variety of symptoms, including weakness, fatigue, myalgias, nausea, vomiting, headaches, altered mental status, focal neurologic deficits, seizures, or coma.  Hyponatremia can be acute or chronic, asymptomatic or symptomatic, and mild or severe.  Sodium levels below 120 mEq/L are severely low.  Neurologic symptoms, such as seizures, altered mental status, and focal neurologic deficits, are also considered severe.  Treatment should be based on patient symptoms, rather than the sodium level, as it can be difficult to assess how acute or chronic the hyponatremia state is on initial evaluation.  The presence of any severe neurologic symptoms as is seen in this scenario should prompt administration of hypertonic saline (3% NaCl).  This allows for rapid correction of serum sodium levels, which should in turn relieve the neurologic symptoms.  A 100-150mL IV bolus of 3% NaCl can be given a second time if symptoms continue after 5-10 minutes.  

Typically, hyponatremia should be corrected slowly to avoid central pontine myelinolysis.  Increases in sodium greater than 8mEq/L per 24hours should be avoided for this reason.  However, in the case of neurologic symptoms, rapid correction of sodium is opted for to prevent further damage.

Administration of “normal saline”, or 1000mL of IV 0.9% NaCl (Choice A), can increase the sodium level.  However, normal saline is not concentrated enough to rapidly increase the serum sodium to terminate neurologic symptoms.  A noncontrast CT scan of the head (Choice B) is a reasonable investigation for this altered patient, but hypertonic saline should be administered first if hyponatremia is known.  Administration of 25mg IV dextrose (Choice C), also known as “D50”, would be helpful in a patient with hypoglycemia and altered mental status. However, this patient is not hypoglycemic.

Administration of hypertonic saline (Choice D) is the best next step in this patient with severe hyponatremia and neurologic symptoms.

Correct Answer: D

References

Cite this article as: Joseph Ciano, USA, "Question Of The Day #46," in International Emergency Medicine Education Project, July 16, 2021, https://iem-student.org/2021/07/16/question-of-the-day-46/, date accessed: September 24, 2021