UMEM Educational Pearls

Category: Pulmonary

Title: Community-Acquired Pneumonia Guideline Update

Keywords: CAP, Pneumonia (PubMed Search)

Posted: 2/1/2020 by Ashley Martinelli (Updated: 10/10/2024)
Click here to contact Ashley Martinelli

The new IDSA and American Thoracic Society guidelines for community acquired pneumonia were recently released.  Major updates to the guidelines include but are not limited to:


1. It is not recommended to obtain sputum cultures in routine care.  Consider only in patients who are intubated or empirically being treated for hospital associated pathogens such as MRSA or P. aeruginosa.

 

2. Blood cultures are only recommended for severe CAP managed in the hospital or those empirically being treated for MRSA or P. aeruginosa, or prior infection with those pathogens, or hospitalized and received parenteral antibiotics in the last 90 days.

 

3. Test for influenza during time periods when influenza is prominent (as in our current 2020 influenza outbreak).

 

4. Healthy patients can receive either amoxicillin 1g TID, doxycycline 100mg BID, or azithromycin 500mg followed by 250mg daily x 4 doses.

 

5. Patients with comorbidities such as chronic heart, lung, liver, or renal disease, diabetes, alcoholism, malignancy, or asplenia should receive combination therapy with a beta-lactam (amoxicillin/clavulanate, cefdinir, or cefpodoxime) + azithromycin or doxycycline.  If allergies preclude the use of a beta-lactam, a fluoroquinolone (levofloxacin or moxifloxacin) can be used.

 

6. Patient admitted for non-severe CAP can receive combination beta-lactam (ampicillin/sulbactam, or ceftriaxone) and azithromycin therapy.  Patients with severe beta-lactam allergies can receive either levofloxacin or moxifloxacin).

 

7. It is no longer recommended to add anaerobic coverage for suspected aspiration pneumonia unless the patient is suspected to have a lung abscess or empyema.  It is most likely a chemical pneumonitis and should resolve within 24-48 hours with supportive therapy.

 

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Category: Critical Care

Title: 2020 Hindsight - looking back at autoimmune encephalitis we may have misdiagnosed for decades

Keywords: Encephalitis, autoimmune, psychosis, movement disorders (PubMed Search)

Posted: 1/24/2020 by Robert Brown, MD (Emailed: 1/28/2020) (Updated: 10/10/2024)
Click here to contact Robert Brown, MD

Question

Dr. Bryan Hayes wrote a Pearl 10/4/2013 to remind us autoimmune encephalitis can present like neuroleptic malignant syndrome.

Dr. Danya Khouja wrote a Pearl 6/28/2017 to inform us autoimmune encephalitis is associated with tumors and can be investigated with serum and CSF antibody panels.

Since those publications, the number of validated autoimmune biomarkers in these panels has increased dramatically. In 2020 we now know, autoimmune encephalitis is at least as common as infectious encephalitis.

Here is how to diagnose it

1. Suspect the diagnosis in patients with subacute/rapidly progressive altered mental status, memory loss, or psychiatric symptoms. It can be mistaken for a new diagnosis of schizophrenia or bipolar disorder. 

2. Look for one or more additional findings: new seizures, focal CNS findings, CSF pleocytosis, MRI findings

3. Exclude other likely etiologies (but try not to get hung up on a positive drug test, especially if drug use was not recent).

Why is this important?

Early treatment with steroids and plasmapheresis can prevent progression of disease (prevent seizures, prevent months-long hospitalizations).

Young girls are especially likely to have teratomas as a cause for the disease. Finding and resecting those tumors is life-saving.

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Category: Orthopedics

Title: Timeliness of Concussion Referral

Keywords: Concussion, (PubMed Search)

Posted: 1/25/2020 by Brian Corwell, MD (Updated: 10/10/2024)
Click here to contact Brian Corwell, MD

Timeliness of Concussion Referral

 

Do patients with a self-limited diagnosis of “concussion” require specialty follow up?

If so, is there a benefit to earlier evaluation?

Recently published research from the University of Pittsburgh Sports Medicine Concussion Program suggests so.

Subjects: 162 concussed athletes between the ages of 12 and 22

Findings: Athletes treated in the first week after injury recovered faster than those who did not receive care until 8 to 21 days post injury.

Note: Once in care the length of time spent recovering was the same for both groups. This suggests that the amount of time prior to the initiation of care may explain the longer recovery time of the 2nd group.

Earlier recovery can help minimize effects on mood, quality of life and lost time in school/work.

Take home:  Consiuder early follow up referral to a qualified provider for all concussed patients seen in the ED

 

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Category: Toxicology

Title: Predictors of fatality from intentional drug overdose

Keywords: risk of death, intentional drug overdose (PubMed Search)

Posted: 1/23/2020 by Hong Kim, MD
Click here to contact Hong Kim, MD

 

Intentional drug overdose (IDO) can lead to significant morbidity and can increased patient's risk of death. A study was recently performed to identify the predictors of death in a cohort of patient who intentionally overdose on drug(s). 

National Self-Harm Registry and National Drug-Related Death Index were reviewed (between January 1st, 2007 and December 31st, 2014) to identify the study cohort.

Results

 

Non fatal IDO

Fatal IDO

Number of cases

63,831

364

Incidence 

148.8/100,000

1.01/100,000

Male

42.0%

55.2%

Age, years (median)

35

44

Multiple drug ingestion

48.5%

78.3%

 

Risk of death

  • 1.7 times higher in MALE compared to female
  • 5 times higher in age > 45 years vs. 15-24 years
  • 3 times higher in patient who ingested 2 – 5 distinct agents, 6x higher in > 6 agent vs. single agent
  • 15 times higher after TCA ingestion
  • 12 times higher after opioids ingestion
  • 4 times higher after antidepressants or illicit substance ingestion/exposure

Conclusion

  • Older age (> 45 years), male gender and ingestion of multiple agents (>2) were associated with higher risk of death from intention drug overdose.

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Mechanical Ventilation Pearls for Acute Ischemic Stroke

  • Patients with an acute ischemic stroke (AIS) may require intubation for various reasons.
  • Two main goals of mechanical ventilation in patients with an AIS are to maintain appropriate oxygen levels and tight control of PaCO2.
  • In terms of oxygenation:
    • Target normoxia
    • Administer O2 if the SpO2 is < 94%
    • Supplemental O2 is not recommended in non-hypoxic patients
  • In terms of CO2:
    • Target normocapnia
    • Hypercapnia increases the risk of intracranial hypertension
    • Hypocapnia can worsen cerebral perfusion

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Category: Pediatrics

Title: Post tonsillectomy complications

Keywords: ENT, post tonsillectomy bleeding, T and A (PubMed Search)

Posted: 1/17/2020 by Jenny Guyther, MD (Updated: 10/10/2024)
Click here to contact Jenny Guyther, MD

Tonsillectomy and adenoidectomy (T&A) is the second most common ambulatory surgery performed in the US.  Children younger than 3 years, children with craniofacial disorders or sleep apnea are typically admitted overnight as studies have shown an increase rate of airway or respiratory complications in this population.

The most common late complications include bleeding and dehydration.  Other complications include nausea, respiratory issues and pain.

Post-operatively, the overall 30-day emergency department return rate is up to 13.3%.  Children ages 2 and younger were more likely to present to the ED.  There is significantly higher risk of dehydration for children under 4 years.  Children over the age of 6 had significantly higher bleeding risk and need for reoperation for hemorrhage control.

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Category: Toxicology

Title: Risk of fatality after ED visit for non fatal opioid overdose

Keywords: non-fatal opioid overdose, risk of fatality (PubMed Search)

Posted: 1/16/2020 by Hong Kim, MD
Click here to contact Hong Kim, MD

 

Many patients are treated in the emergency room for non-fatal opioid overdose. However, it is unknown what proportion of these patient population experience subsequent fatality after their ED visit. 

A recent study investigated the 1-year mortality rate among Massachusetts ED patients who were treated and discharged from ED for non-fatal opioid overdose.

Results

  • 11,557 patients were identified between July 1, 2011 and September 30, 2015.
  • There were 635 fatalities (5.5%) within 1 year in this cohort.
    • Of these, 428 (67.4%) died due to opioid overdose

Of those who died, 

  • 130 (20.5%) died within 1 month
  • 29 (4.6%) died within 2 days.

Manner of death

  • Natural causes: 121 (19.1%)
  • Accidental: 460 (72.4%)
  • Suicide: 13 (2.0%)
  • Other/pending investigation: 41 (6.5%)

Place of death

  • Hospital: 310 (48.8%)
  • Residence: 146 (23.0%)
  • Other/unknown/nursing home: 179 (28.2%)

Conclusion

  • There is high rate of fatality within 1 month (20.5%) after non-fatal opioid overdose ED visits.
  • Subsequent fatal opioid overdose was observed in 428 (67.4%) of the cohort.

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Settings: multicenter, double-blind, phase 3 trial (apparently vitamin D worked in phase 2 trials).

  • Patients:
    • 1059 patients were enrolled within 12 hours of ICU admission.  The patients had to have risk factors warranted ICU admisions (pneumonia, sepsis, mechanical ventilation, shock, pancreatitis, etc.).
    • Vitamin D deficiency was defined as plasma level < 20 ng/ml
  • Intervention:
    • 531 patients received a single oral dose of 540,000 IU of vitamin D3 within 2 hours after randomization
  • Comparison
    • 528 patients received placebo
  • Outcome
    • 90-day all-cause mortality

Study Results:

  • Total SOFA score was similar in both groups (5.6 vs. 5.4).               
  • On day 3, mean plasma vitamin D was higher (47 ng/ml) in treatment group vs 11 ng/ml in placebo group
  • 90-day all cause mortality was similar.  Treatment group was 23.5% vs. 20.6% for placebo (95% CI, −2.1 to 7.9; P = 0.26).
  • Vitamin D-related adverse events were similar in both groups.

Discussion:

  • This trial enrolled patients early in their critical illness compared to phase 2 trial which enrolled patients after 3 days in the ICU.
  • This phase 3 trial also enrolled mostly medical-related illness, whereas 75% of patients in phase 2 had either surgical or neurology-related illnesses.

Conclusion:

Early administration of high dose vitamin D did not improve 90-day all cause mortality.

 

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Category: Airway Management

Title: Medications that may masquerade as Cauda Equina Syndrome

Keywords: back pain, urinary retention, CES (PubMed Search)

Posted: 1/11/2020 by Brian Corwell, MD (Updated: 10/10/2024)
Click here to contact Brian Corwell, MD

Known effects and side effects of prescribed medicines may masquerade as cauda equina syndrome (CES) .

Analgesic medicines used by patients with chronic back pain may also cloud the diagnosis of CES.

Cholinergic medications (glaucoma/myasthenia) may lead to voiding issues.

Anticholinergic medications (COPD/urinary incontinence) may lead to urinary retention.

Opioids – Constipation, reduced bladder sensation

Anticonvulsants (Gabapentin/Pregabalin)- Urinary incontinence

Antidepressants (Amitriptyline) – Urinary retention, sexual dysfunction, reduced awareness of need to pass urine

NSAIDs – Urinary retention.

  • 2.3 fold greater risk versus non users.  Higher in those aged 45 years or older, Highest risk (3.3 fold) was observed in patients who had recently started using NSAIDs. Dose dependent association.  

 

 

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Category: Airway Management

Title: Critical Care Pearls for Adrenal Crisis

Keywords: Adrenal Crisis (PubMed Search)

Posted: 1/7/2020 by Caleb Chan, MD (Updated: 10/10/2024)
Click here to contact Caleb Chan, MD

Adequate treatment of adrenal crisis (AC) is often delayed, even when a h/o adrenal insufficiency is known.

  • most important predictor of AC is a h/o of AC

 

Besides refractory hypotension, also consider in pts with:

  • critically ill pts with eosinophilia (cortisol typically suppresses eosinophil counts)
  • cancer patients who are on check-point inhibitor immunotherapy (they can cause severe hypophysitis or adrenalitis)
  • (inhaled glucocorticoids and topical creams also cause a degree of adrenal insufficiency)

 

Beware of triggers:

  • trauma, recent surgery, even emotional stress/exercise
  • recent initiation of medications that increase hydrocortisone metabolism (avasimibe, carbamazepine, rifampicin, phenytoin, and St. John’s wort extract)
  • recent withdrawal of medications that decrease hydrocortisone metabolism (voriconazole, grapefruit juice, itraconazole, ketoconazole, clarithromycin, lopinavir, nefazodone, posaconazole, ritonavir, saquinavir, telaprevir, telithromycin, and conivaptan)

 

Treatment:

  • 100 mg IV hydrocortisone STAT as a loading dose, followed by 50 mg IV hydrocortisone q6h
  • can also give 40 mg IV methylprednisolone if hydrocortisone is not immediately available
  • can also give 4-6 mg IV decadron instead (will preserve integrity of ACTH stim test to diagnose adrenal insufficiency if it is performed later)

 

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Influenza is a common cause of community-acquired pneumonia and invasive bacterial coinfection may occur.  In addition, secondary bacterial pneumonia due to MRSA is becoming more prevalent.  Due to the higher incidence of MRSA, it is recommended that antibiotics with activity against MRSA (vancomycin or linezolid) be included in the empiric treatment regimen, especially if the patient is critically ill.

Take Home Point: Don’t forget to add MRSA coverage to your empiric treatment regimen in those influenza patients with severe disease or secondary bacterial pneumonia.

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Category: Toxicology

Title: Pharmacobezoar formation in acetaminophen

Keywords: acetaminophen, pharmcobezoar (PubMed Search)

Posted: 1/2/2020 by Hong Kim, MD
Click here to contact Hong Kim, MD

 

Pharmacobezoars (clumps of medication/pills) formation has been demonstrated in few medications such as aspirin, and ferrous sulfate tablets. Their presence can alter management due to prolonged absorption and may cause GI obstruction.

Acetaminophen (APAP) is a commonly available over-the-counter medication that is often implicated in an acute overdose event. A recently published in-vitro study (using pig stomach) investigated whether APAP can form a pharmacobezoar.

APAP group/dosage

  • 25 gm (50 tablets)
  • 37.5 gm (75 tablets)
  • 50 gm (100 tablets)

Positive control group

  • ferrous sulfate (15 gm/50 tablets)

Negative control group

  • chlorpheniramine (200 mg (50 tablets)

Results

  • APAP formed clumps in 37.5 gm and 50 gm groups
  • 83% (5 out of 6) of the 25 gm APAP group did not form clumps.
  • Dissolution profile: APAP clumps released more slowly (over 60 min tested) compared to individual tablet without reaching a peak.

Conclusion

  • APAP can form pharmacobezoar at doses greater than 37.5 gm (in-vitro model) and can result in prolonged or delayed toxicity due to pharmacobezoar formation.

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The arrival of a critically ill pregnant patient to the ED can be anxiety-provoking for emergency physicians as two lives and outcomes must be considered.

Some basic tenets of care, regardless of underlying issue, include:

  • Obtain IV access above the diaphragm to avoid delay/prevention of administered products reaching central circulation due to compression of the IVC by the gravid uterus. 
  • Provide supplemental oxygen as needed to maintain a saturation of >95% which corresponds to a PaO2 >70 mmHg. A PaO2 <60 mmHg is associated with fetal hypoxemia which will quickly lead to fetal acidosis and bradycardia. 
  • Goal maternal PaCO2 is 28-32 mmHg; this respiratory alkalosis maintains a CO2 gradient to help shift offload fetal CO2 into the maternal circulation for clearance. 
  • Hypotensive pregnant patients with a large uterus (20+ weeks) should be turned to the left lateral decubitus position or tilted leftward by at least 15 degrees to offload aortocaval compression and minimize secondary decrease in venous return) by the gravid uterus. 
  • In cases of maternal cardiac arrest, the patient should be kept supine for chest compressions with the gravid uterus manually displaced to the left.
  • Keeping the mother alive is the best way to keep the fetus alive. Standard sedatives, vasopressors, and inotropes are okay if they are needed. Exception for ketamine, which has mixed effects in existing studies and while low doses are probably safe if needed, use as a firstline agent is not recommended. Notify the NICU team of medications given to mother if there is a precipitous delivery.
  • Fetal tococardiometry monitoring if available, or regular POCUS assessment of FHR, in all viable pregnancies.

Finally, once critical illness is identified the OB and NICU teams should be consulted immediately. Fetal distress in a viable pregnancy may be an indication for delivery, and initiation of the transfer process should occur if the supportive specialties are not in-house.

 

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Non-opioid medications such as gabapentin are frequently prescribed for the management of pain. 

A retrospective study of the National Poison Data System (data collected by the U.S. Poison Centers) from 2013 – 2017 showed increasing trend of gabapentin exposure.

Gabapentin exposure increased between 2013 and 2017 by:

  • Total exposure: 72.3% 
  • Isolated intentional suicide attempt: 80.5%
  • Isolated exposure: 67.1%
  • Isolated intentional abuse/misuse: 119.9%

5 most commonly co-ingested substances with gabapentin

  • Sedative-hypnotic: 22.9%
  • Antidepressant: 12.7%
  • Antihypertensive: 9.9%
  • Opioid: 9.0%
  • Antipsychotics: 6.3%

16.7% of the isolated gabapentin exposure required hospitalization.

 

Conclusion:

  • Gabapentin abuse/misuse and ingestion with self-harm intent is increasing in the U.S.


Category: Airway Management

Title: Hemophagocytic Lymphohistiocytosis (HLH)

Keywords: HLH, Hemophagocytic Lymphohistiocytosis (PubMed Search)

Posted: 12/24/2019 by Kim Boswell, MD
Click here to contact Kim Boswell, MD

Hemophagocytic Lymphohistiocytosis (HLH) – Part I

A rare, but important disease that is becoming more widely recognized and more frequently diagnosed. This disease, while uncommon, is rapidly progressive and caries a high mortality rate.

Causes are not completely understood, but involve abnormal activation of the immune response due to a failure of the typical downregulation in hyperinflammatory processes.

Two types exist:

            Congenital/Familial – genetic predisposition which usually requires a triggering event to occur

            Acquired – occurs in adults with no known predisposition (often have underlying genetic predispositions) – triggering events include infections , immunodeficiency, rheumatologic disorders, and malignancy in addition to many others.

Diagnosis is challenging due to the wide variety of symptoms and constellation of symptoms, which often mimic more common infections/sepsis presentations.  Common symptoms include the following:

  • Fever – 95 percentSplenomegaly – 89 percent 
  • Bicytopenia – 92 percent (most often anemia and thrombocytopenia) 
  • Hypertriglyceridemia or hypofibrinogenemia – 90 percent

Symptoms can, and do, occur in any body system – rashes, conjunctivitis, DIC, LFT abnormalities,  hypotension/shock, and respiratory failure are all common concomitant findings in the presentation of HLH

More on the specific diagnosis and treatment to follow in part II...

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Category: Pediatrics

Title: Urinary retention in children

Keywords: Urinary retention, formulas (PubMed Search)

Posted: 12/20/2019 by Jenny Guyther, MD (Updated: 10/10/2024)
Click here to contact Jenny Guyther, MD

Urinary retention in pediatrics is defined as the inability to void for more than 12 hours in the presence of a palpable bladder or a urine volume greater than expected for age.

Maximum urine volume calculation for age:  (age in years + 2) x 30ml.

Causes of urinary retention include mechanical obstruction, infection, fecal impaction, neurological disorders, gynecological disorders and behavioral problems.

The distribution is bimodal occurring between 3 and 5 years and 10 to 13 years.

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Category: Critical Care

Title: Emergent TIPS as treatment for variceal bleeding

Keywords: Cirrhosis, Varices, GI Bleeding, TIPS, Interventional Radiology (PubMed Search)

Posted: 12/17/2019 by Mark Sutherland, MD
Click here to contact Mark Sutherland, MD

There are few conditions that can be as dramatic or difficult to control as variceal GI bleeding in a cirrhotic patient.  It is important to be familiar with all options in these cases, from Blakemore/Minnesota tube placement to massive transfusion to when and which consultants to get involved.  In cases that are refractory or not amenable to endoscopic intervention, emergent interventional radiology consultation for Transjugular Intrahepatic Portosystemic Shunt (TIPS) may be a consideration.  In high risk cases, think about getting IR on the phone at the same time as you engage GI, in case endoscopic management fails.  Variceal bleed patients can decompensate rapidly, get your consultants involved early!

 

Generally accepted indications for emergent TIPS (both of the following should be true):

-GI bleeding not amenable or not controllable by endoscopy

-Cause is felt to be variceal. May also consider in portal hypertensive gastropathy

 

Contraindications:

-Right heart failure or pulmonary hypertension

-Severe liver failure (MELD > 22, T Bili > 3 or Child-Pugh C. In these cases TIPS may not confer a significant survival benefit)

-Hepatic encephalopathy (relative contradindication.  HE may be worsened by TIPS).

-Polycystic liver disease (makes TIPS technically challenging)

-Chronic portal vein thrombus (makes TIPS technically challenging. Acute PV thrombus is NOT considered a contraindication)

 

Bottom Line: In cases of variceal GI bleeding from portal hypertension, consider getting IR on the phone early to discuss emergent TIPS.

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Category: Orthopedics

Title: Radiology in Slipped Capital Femoral Epiphysis

Keywords: Klein's line, S sign, AVN (PubMed Search)

Posted: 12/14/2019 by Brian Corwell, MD (Updated: 10/10/2024)
Click here to contact Brian Corwell, MD

Slipped Capital Femoral Epiphysis (SCFE)

 

  • Progressive, posterior medial displacement (slipping) of the proximal femoral epiphysis
    • Complicated by AVN and premature physis closure

http://www.raymondliumd.com/images/SCFE%20illustrated%20and%20cropped.jpg

Early Diagnosis:

  • Allows best chance for intervention and good functional outcome
  • Subtle and difficult with X-ray
  • Classic teaching is Klein’s line

Klein’s Line on AP view

  • A line drawn from the superior aspect of the femoral neck will not intersect the femoral head epiphysis
  • Modified line
    • >2mm difference in width lateral to line between each side

https://pedemmorsels.com/wp-content/uploads/2018/01/Slipped-Capital-Femoral-Epiphysis-3.png

 

Another virtual line may assist in diagnosis

S-sign

  • The S-sign is a curvilinear line drawn on the inferior margin of the proximal femoral head neck junction along the proximal femoral physis.
  •  Discontinuity or an abrupt sharp turn are abnormal

https://images.squarespace-cdn.com/content/v1/562149a6e4b0bca6fa53cb35/1530197888065-AOF0LA079Y81Q6M89RJU/ke17ZwdGBToddI8pDm48kE2XMWnCJSZ3ROkmIxQ7DdsUqsxRUqqbr1mOJYKfIPR7LoDQ9mXPOjoJoqy81S2I8N_N4V1vUb5AoIIIbLZhVYxCRW4BPu10St3TBAUQYVKcIZH9X6Fb-UKi0lvZd9RVmtFt1P_lj4JzgsdTxe78uiejbzfgXQaCWxJNArJhpf7P/Screen+Shot+2018-06-26+at+10.09.17+AM.png?format=1500w

Klein's line and S-sign

  • A group of 20 orthopedic surgeons, radiologists, and pediatricians viewed 35 radiographs of SCFE using Klein's line on the AP view and the S-sign on frog-leg lateral view to make the diagnosis. 
  • Overall diagnostic accuracy was better with the S-sign than Klein's line, 92% vs 79%.
    • Sensitivity of the S-sign was 89%, specificity 95%. 
    • Sensitivity of Klein's line was 68%, specificity 89%. 
  • Combined S-sign + Klein's line sensitivity was 96%, specificity 85%.

 

Consider adding both of these virtual lines/signs to your review of the pediatric hip plain film

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Category: Critical Care

Title: DDAVP for intracranial hemorrhage

Keywords: DDAVP, desmopressin, ICH, intracranial hemorrhage, stroke, CVA, hyponatremia (PubMed Search)

Posted: 12/8/2019 by Robert Brown, MD (Emailed: 12/10/2019) (Updated: 12/10/2019)
Click here to contact Robert Brown, MD

Question

Pearl: consider desmopressin (DDAVP) for patients with an intracranial hemorrhage who are taking an antiplatelet. Caution, this is not for patients with an ischemic stroke with hemorrhagic conversion and it was not specifically evaluated for patients on anticoagulation or going to the OR with neurosurgery.

How strong is this evidence? International guidelines already give cautious approval for this practice, and now there is a retrospective review to support it. Though there were only 124 patients in the trial, the rate of hemorrhage expansion was much lower in the DDAVP group (10.9% vs 36.2%, P = .002) and there was no increased risk of hyponatremia (no events reported).

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Category: Pharmacology & Therapeutics

Title: Adenosine Administration

Keywords: adenosine, SVT (PubMed Search)

Posted: 12/8/2019 by Ashley Martinelli (Updated: 10/10/2024)
Click here to contact Ashley Martinelli

Adenosine is an atrioventricular nodal blocking agent that is commonly used in the treatment of supraventricular tachycardia.  It is dosed as 6 mg IV Push x 1, followed by dose escalation to 12 mg IV Push if the initial dose was unsuccessful.  In patients with central access or prior orthotopic heart transplantation, the initial recommended dose is 3 mg.

Due to its short half-life (< 10 seconds) it is imperative to administer in the most proximal access and follow with a 20 mL bolus of saline.  Traditionally this is done using a two-way stopcock. 

A new study compared single syringe (adenosine 6mg + 18 mL saline) vs two syringes (adenosine 6mg in one, 20 mL saline in the other) in 53 patients with SVT.  The single syringe arm converted to NSR 73.1% after one dose compared to 40.7% in the two-syringe arm (p=0.0176).  After up to three doses, the single syringe arm had 100% conversion compared to 70.4% in the two-syringe arm (p=0.0043).

Single syringe adenosine has been recommended in FOAM for several years.  Although small, this study is the first to compare the two methods.  This method simplifies administration and may improve cardioversion rates.

 

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