UMEM Educational Pearls

Many may look at the Inferior Vena Cava (IVC) to get a sense of a patient's “fluid responsiveness.” However, there are many pitfalls to using the IVC. An article by Via et al outlines these pitfalls and is an interesting read! 

To summarize, IVC can be affected by:

1. Ventilator Settings such as high PEEP
2. Patient's inspiratory efforts such as significant respiratory efforts
3. Asthma/COPD exacerbations
4. Cardiac Conditions impeding venous return such as tamponade or RV dysfunction
5. Increased abdominal pressure such as intra-abdominal hypertension
6. Other factors such as asking the patient to take a breath in, poor measurements, ivc compression by masses or ECMO cannulae

Bottom Line: Think twice before using IVC to evaluate for fluid responsiveness.

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The Bova score has been validated to predict mortality and complications in hemodynamically stable patients with intermediate to high-risk pulmonary embolisms.  There is some literature on using the Bova score to decide on thrombolytics/interventional therapy as well. 

Scoring Criteria:

1. Score 2: Systolic Blood Pressure 90-100 mmHg
2. Score 2: Elevated cardiac Troponin
3. Score 2: Right Ventricular Dysfunction
   1. Right Ventricle to Left Ventricle ratio >0.9
   2. Systolic pulmonary artery pressure >30 mmHg
   3. Right ventricular free wall hypokinesis
   4. Right ventricular dilatation (e.g. D-Sign)
4. Score 1: Heart Rate >=110 bmp

Interpretation:

1. Stage 1: Bova Score 0-2 (low risk)
   1. Mortality at 30 days: 3.1%
   2. PE Related Complications: 4.4%
2. Stage 2: Bova Score 2-4 (intermediate risk)
   1. Mortality at 30 days: 6.8%
   2. PE Related Complications: 18%
3. Stage 3: Bova Score >4 (high risk)
   1. Mortality at 30 days: 10%
   2. PE Related Complications: 42%

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A 2020 meta-analysis attempted to estimate the frequency of radiographically occult hip fractures in the elderly population.

26 studies evaluated the rate of surgical hip fractures with no obvious findings on plain film.

Median age 80.3 years (67-82 years). 

MRI used as gold standard.

The overall rate of radiographically occult hip fracture requiring surgery was 39%.

This percentage is higher than reported in other studies which may have included non-elderly patients, retrospective bias or other issues.

Overall, 18% had femoral neck fractures, 17% had intertrochanteric fractures and 1% had subtrochanteric fractures. 

Elderly patients with acute hip pain and negative or equivocal findings with initial plain film imaging have a high frequency of occult hip fractures. Strongly consider advanced imaging in this population

Question

At our institution we have developed a guideline for the use of hypertonic saline in hyponatremia.

Administration of 3% sodium chloride for acute or symptomatic hyponatremia

• Bolus doses are preferred over continuous infusion.
• Use in patients with rapid decline in serum sodium levels (>= 10 mEq decrease over 24 hours) or symptomatic (e.g. seizures).
• Do not attempt to normalize the serum sodium level in the first 24 hours.
• Serum sodium correction should be no more than 8-10 mEq/L in a 24-hour period.
  • 8 mEq/L (or less) should be used in patients at high risk for osmotic demyelination syndrome
  • High risk populations: chronic hyponatremia, hypokalemia, alcoholism, malnutrition, or liver disease
• Chronic hyponatremia should be corrected over days with a goal of 4-8 mEq/L in 24 hours.
  • Fluid restriction should be considered first-line for chronic hyponatremia.

Acute hyponatremia with severe symptoms

• Bolus 3% sodium chloride 150 mL over 10 minutes.
• If symptoms persist repeat up to 3 doses over 30 minutes.

Acute hyponatremia with moderate symptoms

• Bolus 3% sodium chloride 150 mL over 20 minutes once.

Hyponatremia Fluid Rate Calculations (**Be Careful with Online Calculators**)

FYI: 3% Sodium Chloride (1.95 mL/mEq; 513 mEq/1 L); 0.9% Sodium Chloride (6.5 mL/mEq; 154 mEq/1 L)

Equations for Calculations

1. Sodium correction for HYPERglycemia
   1. Corrected Na=Observed Na + 0.016 x (serum glucose-100)
2. Calculated Sodium Deficit
   1. Female: (Desired Na – Observed Na) x 0.5 L/kg x weight (kg)
   2. Male: (Desired Na – Observed Na) x 0.6 L/kg x weight (kg)
   3. This equation will give you the total mEq of Na needed in 24 hours.
   4. Remember: Correction should be no more than 8 mEq/L in 24 hours in most cases.
3. Calculated Infusion Rate for Sodium Correction
   1. ___ mEq Na required (from Equation 2) x ___ mL/mEq of fluid = ___ mL of fluid
   2. ___ mL of fluid / 24 hours = ___ mL/hr of fluid

***See Visual Diagnosis for an Example with Calculations***

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I don't know about you, but I'm always eager to hear new and alternative methods of pain control…

This study examined the effectiveness of transcutaneous electrical nerve stilumlation (TENS) in patients with abdominal pain. Patients were randomized to TENS or sham applied to the abdomen. The primary outcome of interest was change in pain score 30 min after the intervention, and secondary outcome was percentage of patients requiring rescue analgesia. Pain scores were measured on a verbal numeric score scale with a range from 0 to 10, with any adult patients with a minimum score of 5 being eligible. 

The mean reductions in pain scores after the intervention were also similar in patients treated with TENS and sham TENS (1.9 vs. 1.7 respectively, p = 0.81). THe use of rescue analgesia was 49% in patients treated with TENS and 51% in those who received sham TENS (p=0.66). No adverse events were noted. 

The authors did note that there is a challenge in blinding due to toeh absence of electrical stimulation in the sham group; nonetheless, TENS was not found to be more effective than sham.  It also did not reduce the need to rescue analgesia.

Guess I'll keep looking…

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This May, the Society of Critical Care Medicine (SCCM) published new recommendations [1] for the use of corticosteroids in critical illness (separate from patients with known adrenal insufficiency or on chronic steroids), namely:

1. “Suggesting” for all septic shock with continued vasopressor requirement not just “refractory” (requiring 2+ pressors) 
   • Matches the 2021 Surviving Sepsis Campaign Guidelines suggestion [2]
2. “Suggesting” for ARDS (acute onset, bilateral infiltrates not due to cardiac dysfunction or volume overload, PaO2: FiO2 </= 300)
   • Matches the 2024 American Thoracic Society Clinical Practice Guidelines suggestion [3]
   • Does not explicitly exclude influenza+ ARDS, in which steroids have previously been associated with worsened outcomes [4]
3. “Recommending” for patients with bacterial community acquired pneumonia and new O2 requirement
   • New guidelines from ATS/IDSA not yet updated from 2019; support primarily from 2023 CAPE COD trial [5]

Bottom Line:

For severe bacterial pneumonia and septic shock, ED physicians should feel comfortable administering a dose of hydrocortisone 50mg IV as hydrocortisone 200mg/day is an accepted regimen for these disease processes. 

For patients with ARDS who remain boarding in the ED, EM docs should discuss initiation of steroids with their intensivists, whether the institutional preference is for dexamethasone 20mg IV (per DEXA-ARDS) [6] or methylprednisolone 1mg/kg/day (per Meduri)[7].

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POCUS has been shown to have a 92.4% sensitive (95% CI 89.0% to 94.7%) and 96.6% specific for identifying SBO. 

Some characteristics of SBO include:

-dilated fluid filled bowel  

-contents of bowel moving to and fro like a washer machine 

-wall thickening and ability to see plicae circulares 

- in high grade obstruction you may also notice intraperitoneal fluid near the dilated bowel. 

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Question

Patient struck in left eye. The patient was asked to look up during exam and this is the finding. What imaging modality would you order if so inclined, what is the injury, and what is the disposition/plan? 

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Shenton's line

Hypokalemia is a common electrolyte abnormality found in pediatric patients. The cut off for low potassium is based on age, with young infants having higher baseline levels of potassium when compared to older children and adults. The most common cause of hypokalemia in children is GI losses (diarrhea), though other considerations include malnutrition, congenital adrenal hyperplasia, renal abnormalities and medication effects. 

Typically, hypokalemia is well tolerated, and the focus of management is based on treating the underlying cause, rather than repleting the potassium. 

Medications should ONLY be initiated in patients who have potassium levels < 3.0 mmol/L OR with those with levels < 3.5 mmol/L with ECG changes. 

In patients receiving treatment, oral potassium administration is typically recommended unless any of the following criteria are met:

• Potassium level < 2.5 mmol/L
• Inability to tolerate PO
• There are any ECG changes concerning for hypokalemia

In these patients IV potassium should be given (typically KCl at 0.5-1mEq/kg/DOSE - Max of 40 mEq/dose). 

Just like in adults, ALL patients require continuous cardiac monitoring when receiving potassium infusions.

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Spontaneous coronary artery dissection (SCAD) occurs when there is an intimal tear that develops within the wall of an epicardial coronary artery, leading to intramural hematoma and false lumen formation with compromised coronary blood flow.  This tear develops in the absence of atherosclerosis, trauma, or iatrogenic injury. SCAD is believed to account for 4% of acute coronary syndromes, and has been found to be the cause of ACS in 35% of women under the age of 50. Women comprise the majority of cases of SCAD( 87-95%). 

Patients with Pregnancy-associated SCAD (P-SCAD) will often present with higher-risk features and more severe presentations compared with non-pregnancy related SCAD. They are more likely to present with STEMI (>>NSTEMI), impaired left ventricular function, left main and multivessel disease, and shock than other cohorts of SCAD patients.

The peak timing of P-SCAD is within the first month postpartum (with the highest incidence within the first week), although cases can occur throughout all trimesters of pregnancy or many months postpartum.

Keep SCAD in your differential for patients without typical risk factors who present with signs/symptoms of ACS. A strong index of suspicion is necessary to prevent bad outcomes and improve morbidity and mortality from this disease entity.

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Noninvasive Ventilation for Preoxygenation

• Over 1 million critically ill patients are intubated each year in the United States.
• Hypoxemia can occur in up to 20% of intubations and may lead to adverse outcomes such as peri-intubation cardiovascular collapse or cardiac arrest.
• Appropriate preoxygenation is critical to increase the safe apnea time and decrease the risk of hypoxemia during rapid sequence intubation (RSI).
• At present, the majority of critically ill patients undergoing RSI are preoxygenated with an oxygen mask.
• In a randomized, pragmatic, parallel-group trial conducted in 7 EDs and 15 ICUs in the United States, Gibbs et al compared the use of noninvasive ventilation for preoxygenation to an oxygen mask on the incidence of hypoxemia during intubation.
• In over 1,300 patients, the incidence of hypoxemia during the interval between induction and 2 minutes after intubation was markedly lower in patients preoxygenated with noninvasive ventilation compared to those preoxygenation with an oxygen mask.
• Importantly, the greatest benefit to noninvasive ventilation for preoxygenation was seen in patients with acute hypoxemic respiratory failure, those requiring > 70% FiO2 prior to intubation, and those with a BMI > 30.
• Lastly, the trial did not enroll patients who needed emergent intubation without time for at least 3 minutes of preoxygenation.

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192 trauma patients who were receiving pre-hospital fentanyl for moderate to severe pain  were randomized to placebo or intranasal 50 mg ketamine as an adjunct for pain control. There was no difference between the two groups in decrease in pain scale. 
The authors concluded: “In our sample, we did not detect an analgesic benefit of adding 50 mg intranasal ketamine to fentanyl in out-of-hospital trauma patients.”

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Needed for sample size determination

Power – (1-beta), where beta is the risk of a type 2 error – rejecting the accepting the null hypothesis when it is true – this is usually selected to be 0.8 or 0.9.

Significance (alpha), the chance of making a type 1 error – accepting the alternate hypothesis when the null hypothesis is true. This is usually selected to be 0.05.

One-tailed or two-tailed – is the null hypothesis one of no difference (experimental arm not better or worse) or one-sided (experimental arm not better)?

Effect Size. This is the challenging part. This is the size of the difference in outcomes you’re looking for. 

  For continuous outcomes (example – difference in pain scores). You’ll need an estimate for the variation in the scores between presentations, or the standard deviation. You can get this from a literature estimate or a from small local measurement, say of 10 patients or so.

  For a dichotomous outcome (example – percentage of successes), you can usually estimate the percentage in one group and choose the difference you are looking for.

The effect size has a big effect on the sample size. Generally, cutting the effect size in half increases the sample size by fourfold.

Statistical software - next pearl.

Prioritizing the timely admission of older patients from the emergency department (ED) to appropriate wards is essential to reduce adverse events, such as falls and infections, and to decrease the duration of hospital stays. Recent cohort studies, both observational and prospective, have demonstrated that elderly patients who experienced prolonged or overnight stays in the ED had a higher in-hospital mortality rate compared to those who were admitted earlier to inpatient care. Efficient patient flow and early admission from the ED to appropriate wards are crucial strategies for improving survival rates and reducing morbidity among older patients.

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The systematic review of presyncope literature found that presyncope should be treated the same as syncope in terms of work up and disposition.

“In conclusion, the prevalence of short-term serious outcomes among ED patients with presyncope ranges from one in four to one in 20, with arrhythmia being the most common serious outcome. Our review indicates that presyncope may carry a similar risk to syncope, and hence, the same level of caution should be exercised for ED presyncope management as that of ED syncope.”

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“Administrative harm” (defined as “the adverse consequences of administrative decisions within health care”) is a relatively new term for challenges that arise in complex health care work environments. 

41 mostly hospitalists participating in interviews and focus groups found that the concept resonated, and that administrative harms could arise at all levels of leadership, negatively impacted both workforce and patients, were challenging to measure, and pointed to a lack of leadership responsibility and accountability. The group also suggested many approaches and solutions for prevention.

The article is here, https://jamanetwork.com/journals/jamainternalmedicine/fullarticle/2820266. If interested, take a look at the thematic tables 2 and 3.

There is a brief editorial comment here, https://jamanetwork.com/journals/jamainternalmedicine/article-abstract/2820275.

Background: Sepsis remains a common entity associated with a relatively high rate of inpatient mortality, with timely recognition and treatment being key to improving patient outcomes. Various screening and warning scores have been created to attempt to identify sepsis and those patients at high risk of mortality earlier, but have limited performance because of suboptimal sensitivity and specificity.

A prospective observational study compared the performance of a variety of these scores (SIRS, qSOFA, SOFA, MEWS) as well as a machine learning model (MLM) against ED physician gestalt in diagnosing sepsis within the first 15 minutes of ED arrival. 

• 2550 patients deemed by EMS or triage nurse as potentially critically-ill
  • Excluded trauma, cardiac arrest, acute MI, stroke activation, patients in labor
• Seen by ED attendings (94%) / senior residents (6%) at a single urban academic center
  • Visual analog scale assessment, 0-100% likelihood that patient has sepsis
  • VAS >50% treated as ED physician gestalt in favor of sepsis
• 275 patients ultimately with discharge diagnosis of sepsis present on arrival to hospital
• Initial VAS outperformed all scores (AUC 0.90; 95% CI 0.88 to 0.92) both at 15 minutes and 1 hour

Although not without its limitations, this study highlights the importance and relative accuracy of physician gestalt in recognizing sepsis, with implications for how to develop future screening tools and limit unnecessary exposure to unnecessary fluids and empiric broad spectrum antibiotics.

Bottom Line: In the era of machine learning models and AI, ED physicians are not obsolete. Even at 15 minutes, without lab results and diagnostics, our assessments lead to appropriate diagnoses and care. In this new normal of prolonged wait times and ED boarding, ED triage and evaluation models that optimize early physician assessment are of the utmost importance.

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Author:

Gabriella Miller (She/Her)

Clinical Instructor

Department of Emergency Medicine

University of Maryland School of Medicine

Doxycycline PEP for the prevention of bacterial STIs.

The CDC now recommends “doxy PEP” for high-risk individuals. Doxycycline post-exposure prophylaxis (doxy PEP) is a prescription for patients to self-administer 200 mg doxycycline by mouth within 72 hours after anal, oral, or vaginal sex to prevent the transmission of chlamydia, gonorrhea, and syphilis. The CDC defines “high-risk” as men who have sex with men (MSM) and transgender women (TGW) who have been diagnosed with a bacterial STI within the past 12 months. They summarize the findings of the French IPERGAY and ANRS DOXYVAC studies, as well as the US DoxyPEP study, which all show promising reductions in risk ratios or hazard ratios of decreasing bacterial STI transmission on high-risk populations, including those who are taking PrEP for HIV. No significant adverse events related to doxy PEP have been reported.

Conclusion:

Counsel patients at high risk for bacterial STIs regarding the prescription of doxy-PEP for patient self-administration within 72 hours after sex.

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Two recommendations from the recent GRACE 4 publication in Academic Emergency Medicine to consider:

1. Use phenobarbital along with benzodiazepines in patients with moderate to severe alcohol withdrawal. The evidence isn’t robust but is positive when compared to benzos alone.

2. Adults with alcohol use disorder can benefit from anti-craving medications such as naloxone and gabapentin at time of discharge.

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