UMEM Educational Pearls - By Ashley Martinelli

Bottom Line: Droperidol is an effective alternative to haloperidol in the treatment of gastroparesis although most patients will also receive prokinetic agents as well such as metoclopramide. It may also have some analgesic benefit.

Prior studies have demonstrated the efficacy and safety of haloperidol in the management of gastroparesis. A recent retrospective study was conducted to assess the impact of droperidol as it is an effective antiemetic similar to haloperidol.

This study enrolled 233 patients.  Visits were matched with their most recent ED visit > 7 prior where droperidol was not administered. 

Most patients were female, 51% African American, and the median age was 40.  Doses ranged from 0.625 mg – 2.5 mg with the most common dose being 1.25 mg. 

Results:

  • 46% of the droperidol visits received opioids compared to 60% when droperidol was not given (p=0.004)
  • Droperidol was noted to reduce pain scores from 9 (IQR 7-10) to 5 (IQR 0-8) (p=0.0001)
  • Droperidol visits were prescribed fewer antiemetic agents 60% vs 73% (p=0.0045)
  • There was no difference in the use of prokinetic agents (metoclopramide)
  • No difference in ED or hospital LOS or admission rates (~30%), cost, or adverse events

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Emergency contraception is highly effective at preventing unwanted pregnancies and has been on the market for 20+ years.

Levonogestrel (LNG) 1.5 mg PO x 1 dose  (OTC Available)

Ulipristal acetate (UPA) 30 mg PO x 1 dose (Requires RX)

Original studies with LNG was estimated to prevent up to 80% of expected pregnancies.  In the subsequent trials that brought UPA to the market and compared the two medications, LNG prevented 69% (95% CI, 46-82%) and 52.2% (95% CI, 25.1-69.5%).

While pregnancy rates are low with both options there is concern with patients of higher weight/BMI that the effectiveness of levonorgestrel decreases as weight rises. One large study of over 1700 patients specifically noted that a weight > 75 kg was associated with up to 6.5% pregnancy rate (95% CI 3.1-11.5) compared to 1.4% (95% CI 0.5-3.0) in patients weighing 65-75 kg.  Patients weighing > 85 kg had similarly high rates at 5.7% (95% CI 2.9-10.0).

The cost difference is minimal between products, especially when considering costs associated with treatment failures and subsequent need for care- the largest difference is with respect to access as LNG is OTC and UPA requires an RX.  Either can be administered in an ED setting as long as they are on formulary.

ACOG also recommends that ulipristal be utilized for it higher overall efficacy compared to levonorgestrel. 

Consider:

For patients above 75 kg, ulipristal can be used as first line emergency contraception for up to 5 days following unprotected intercourse.

Patients < 75 kg and < 72 hours following unprotected intercourse can use levonorgestrel or ulipristal as an appropriate emergency contraception method.

Patients < 75 kg and 72-120 hours following unprotected intercourse should use ulipristal due to its efficacy beyond 72 hours.

 

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Category: Pharmacology & Therapeutics

Title: Calcium may not prevent diltiazem-induced hypotension

Keywords: atrial fibrillation, atrial flutter, diltiazem, calcium (PubMed Search)

Posted: 3/3/2023 by Ashley Martinelli (Emailed: 3/4/2023) (Updated: 3/18/2024)
Click here to contact Ashley Martinelli

Non-dihydropyridine calcium channel blockers, verapamil and diltiazem, can induce hypotension when administered intravenously (IV) in approximately 4% of patients.  It has previously been taught that administering IV calcium before administering these medications may prevent the hypotension.  Previously, this theory was tested for verapamil and found success with reducing hypotension.  Only one study has been done exclusively with diltiazem and it found no benefit. 

In a new multicenter retrospective cohort study of adults in the ED, patients were randomized into two groups: those who received diltiazem alone and those who received calcium with diltiazem for atrial fibrillation/atrial flutter (AF/AFL) with a HR ≥ 120 bpm. Patients were excluded if they required electrocardioversion, had other agents prior to diltiazem, incomplete information, were pregnant or incarcerated. The primary outcome was change in SBP 60 minutes (+/-30 minutes) after diltiazem administration.

Baseline characteristics: 73 year old, equal male:female, predominantly white patients.  40% had new onset AF/AFL and the initial HR was 140 in both groups. There were 198 patients in the diltiazem group and 56 patients in the combination group.  Notably, patients in the combination group had a lower presenting SBP 109 (101-121) vs 123 (114-132) P<0.0001 which matches classical teaching for when to consider calcium use. Additionally, patients in the combination group received a lower diltiazem dose of 10mg vs 15mg in the monotherapy group p=0.004 with both group receiving doses lower than the standard 0.25 mg/kg dosing recommendation.

Outcomes:

  • Median change in SBP was not different between the monotherapy and combination therapy groups: (-2 mmHg vs -1.5 mmHg, p= 0.642)
  • There was no difference in:
    • Time to rate control (1.4 vs 1.8 hours, p= 0.141)
    • Time to sustained rate control (7.9 vs 7.7 hours, p=0.570)
    • Change in HR at 60 minutes: (-33 vs -34 bpm, p=0.428)
  • A subgroup analysis looking at timing of calcium (i.e. before or with diltiazem administration) also found no difference.


Take Home Point:

Administration of IV calcium may not be as beneficial as previously thought to prevent hypotension induced by diltiazem administration.  This particular study is confounded by the relatively low doses of diltiazem overall, but utilizing a lower dosing strategy in patients with low SBP is a reasonable safety strategy.

 

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Category: Pharmacology & Therapeutics

Title: Beware of piperacillin-tazobactam dose reductions in septic shock

Keywords: sepsis, piperacillin-tazobactam (PubMed Search)

Posted: 9/29/2022 by Ashley Martinelli (Emailed: 10/3/2022) (Updated: 3/18/2024)
Click here to contact Ashley Martinelli

Piperacillin-tazobactam is one of the most commonly used antipseudomonal antibiotics in the empiric management of patients with septic shock. The package insert recommends dose reductions for renal impairment in other infectious etiologies, but the impact of dose reduction has not been previously studied in patients with septic shock.

A recent retrospective, observational cohort study compared outcomes of patients with septic shock who received ≥ 27 grams (at least 3.375 gm q6 hours x 48 h-“NORM”) versus those who received < 27 grams (“LOW”) over the initial 48 h of septic shock (defined as concomitant norepinephrine infusion).  

Patients were excluded if they had death or hospice disposition within the 48h study period. The primary outcome was the number of norepinephrine free days (NFD) at day 28. Propensity matching was utilized to account for confounders.

Results: 351 in the LOW group, 928 in the NORM group with 608 pairs in the propensity matched assessment.

  • Patients in the LOW group were
    • Older (65 v 61, p < 0.001)
    • More likely to have lower renal function (20% with CrCl < 20, 35% with CrCl 20-40) which corresponds to package insert dose reduction recommendations
    • Received lower doses of piperacillin/tazobactam (20.3 g v 30.4 g, < 0.001)
  • Norepinephrine free days were statistically significantly higher in the NORM dosing group when looking at all patients and the propensity score matched patients.
  • In-hospital mortality/hospice disposition was also lower in the NORM group (25.9% v 35.5%, p=0.014

Bottom Line: Dose reductions of piperacillin-tazobactam appears to be harmful early in the management of patients with septic shock.

 

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Prior studies have found that patients are at an increased risk for hypoglycemia when administered insulin for the acute management of hyperkalemia when they have renal dysfunction.  A new single-center, retrospective study investigated the risk of hypoglycemia and the overall effect of potassium lowering in patients with renal dysfunction and stratified outcomes based on the CKD level.

Patients were included if they were ordered insulin for hyperkalemia using a hospital driven order set and had CKD stages 3a, 3b, and 4.  They were excluded if they had dialysis within 6h of insulin administration, had DKA, or no repeat labs.  The hospital order set encourages 5 units of insulin instead of 10 when “renal failure” is present without clear guidance.

377 patients were included: 186 received 5 units and 191 received 10 units.  The average age was 65 years old, predominantly male, weighing 90 kg.  In the 5 unit group, significantly more patients had CKD stage 4 (60% v 30%) and in the 10 unit group, significantly more patients were CKD stage 3a (p<0.001).  The baseline serum potassium was 6 in each group.

The hypoglycemia incidence was not different between groups, with severe hypoglycemia occurring twice per group.  All patients received dextrose according to the protocol.

There was a significant difference in the reduction of serum potassium between the 5 and 10 unit groups: -0.63 mmol/L vs -0.9 mmol/L (p 0.001).

Bottom line:  Hypoglycemia occurred even with insulin dose reduction.  Potassium lowering was higher in patients who received the 10 unit dose.

 

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Category: Pharmacology & Therapeutics

Title: To B or Not to B: B52 v 52 for Acute Agitation

Keywords: haloperidol, agitation, sedation (PubMed Search)

Posted: 4/2/2022 by Ashley Martinelli (Updated: 3/18/2024)
Click here to contact Ashley Martinelli

Diphenhydramine (B) has historically been utilized in combination with haloperidol 5mg (5) and lorazepam 2mg (2) in the treatment of acute agitation.  The most common rationale for adding diphenhydramine is prevention of EPS, however literature to support this is lacking.  A recently published paper examined diphenhydramine/haloperidol/lorazepam combination (B52) vs haloperidol/lorazepam combination therapy (52) to compare the need for additional agitation treatments as a surrogate for clinical efficacy.

 

This retrospective, multicentered noninferiority study included 400 emergency medicine patients, 200 per treatment arm. On average, the patients were 40 years old, 64% male, and predominantly Caucasian.  More patients in the B52 group had psychiatric illness listed as their primary cause for agitation compared to the 52 group. The two most frequently reported substances on urine drug screens, if collected, were amphetamines (35%) and cannabinoid (35.5%).

 

Results:

-No difference in the use of additional agitation medications within 2 hours

-More patients in the 52 group were noted to receive anticholinergic medications within 2 days, but indications varied and were not associated with EPS treatment

 

The B52 combination was associated with:

---Increased length of stay 17 h (10-26) vs 13.8 h (9-12), p = 0.03

---Increased use of restraints 43% vs 26.5%, p = 0.001

---Hypotension 16% vs 3.5%, p <0.001

---Use of nasal canula oxygen 3% vs 0%, p < 0.01

 

The addition of diphenhydramine may not be necessary to prevent EPS in patients receiving haloperidol for agitation and is associated with increased length of stay and adverse events, likely due to its additive sedative properties. 

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Category: Pharmacology & Therapeutics

Title: Calcium for Out-of-Hospital Cardiac Arrest

Keywords: Calcium, cardiac arrest (PubMed Search)

Posted: 12/4/2021 by Ashley Martinelli (Updated: 3/18/2024)
Click here to contact Ashley Martinelli

Calcium is commonly administered during cardiac arrest, but there is little data to support or refute its use.  The Calcium for Out-of-Hospital Cardiac Arrest trial was a randomized, double-blind, placebo-controlled parallel group study conducted in Denmark.  Their EMS system responds to all cardiac arrests with an ambulance and a physician-manned mobile emergency care unit.

Adult patients were included if they had out of-of-hospital (OOH) cardiac arrest and received at least 1 dose of epinephrine. Exclusion criteria were traumatic arrest, known or suspected pregnancy, prior enrollment in the trial, receipt of epinephrine from an EMS unit not in the trial, or a clinical indication for calcium during the arrest (i.e. hyperkalemia or hypocalcemia).

Patients received 735mg calcium chloride dihydrate (5 mmol CaCl –US standard product is 1000mg) or saline control immediately after the first dose of epinephrine.  A second dose was administered after the second dose of epinephrine if cardiac arrest ongoing. Teams were blinded to the treatments. The primary outcome was ROSC for at least 20 minutes.

397 patients were randomized (197 calcium, 200 saline). The average age was 68 years old, 70% were male, and over 80% of the cardiac arrests occurred at home, 60% witnessed arrests, and 82% received bystander CPR. Only 25% were in a shockable rhythm. The time to first epinephrine and study drug was approximately 17 minutes and over 70% received two doses.

ROSC rates were low and not statistically different between groups, 19% in the calcium group vs 27% in the saline group.  There was no difference in survival to 30d or neurologic function. In the patients who did achieve ROSC in the calcium arm, 74% had hypercalcemia.

Bottom Line: The routine use of calcium in out-of-hospital cardiac arrest is not recommended.

 

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 Vancomycin infusion reactions can manifest as pruritus and an erythematous rash of the neck, face, and torso during or after a vancomycin infusion.  This is a histamine reaction caused by degranulation of mast cells and basophils, and can be caused short infusion times <60 min.  It is commonly treated with antihistamines and/or a slowing of the infusion rate. 

Historically, this has been called “Red Man Syndrome.”  As we move towards more inclusive language in medicine, it is increasingly necessary to remove language that is insensitive and/or offensive.  Not only is “Red Man Syndrome” offensive towards Native Americans, it also is an inaccurate term that implies a clinical presentation in white male patients when this reaction can occur in any race or gender. 
The preferred terminology is now “vancomycin infusion reaction” or “vancomycin flushing reaction” and is supported by physician, pharmacist, and pediatric professional publications.    
Allergy documentation matters.  Always include descriptors of the reaction to avoid labeling patients “vancomycin allergic” if it truly was an infusion reaction as this can lead to suboptimal second line therapy being unnecessarily selected.  
 
What you can do:
1.       Replace “Red Man Syndrome” with vancomycin infusion reaction in your teaching and vernacular
2.       Remove “Red Man Syndrome” from patient allergies and replace with Vancomycin Infusion Reaction with a short description of what the patient experienced
3.       Avoid using “Red Man Syndrome” in your future scholarly works and publications

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Tranexamic acid (TXA) is an antifibrinolytic medication that has been trialed in previous small studies to treat epistaxis. The data to this point has not reliably shown a reduction in bleeding at 30 minutes, but has demonstrated an increased rate of discharge at 2 hours and a reduction in re-bleeding events.

The NoPAC study was the largest study to date on TXA for epistaxis. It was a double-blind, placebo-controlled, randomized study of TXA in adult patients with persistent atraumatic epistaxis to determine if TXA use decreased the rate of anterior nasal packing. Patients were excluded if they had trauma, out of hospital nasal packing, allergy to TXA, nasopharyngeal malignancy, hemophilia, pregnancy, or if they were referred to ENT.

Eligible patients completed 10 minutes of first aid measures followed by 10 minutes of topical vasoconstrictor application prior to randomization to either placebo of 200mg TXA soaked dental rolls inserted in the nare.

496 patients were enrolled. The average patient was 70 years old with stable vitals 150/80mmHg, HR 80 bpm with >60% on oral anticoagulants.

TXA did not reduce the need for anterior nasal packing: 100 (41.3% placebo) vs 111 (43.7% TXA) OR 1.11 (0.77-1.59). There were no differences in the rates of adverse events.

Bottom Line: TXA does not improve rates of anterior nasal packing for patients with persistent epistaxis.

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Opioid Conversion Updates

Updated in 2018, some clinicians are unaware of the changes to the opioid conversion tables.

 

2010 Recommendations

 

2018 Updates

Opioid

IV (mg)

PO (mg)

 

IV (mg)

PO (mg)

Morphine

10

30

 

10

25

Fentanyl

0.1

NA

 

0.15

NA

Hydromorphone

1.5

7.5

 

2

5

Oxycodone

NA

20

 

NA

20

 

When converting between opioids, it is important to remember the following steps:

  1. Determine the patient’s level of pain and current response to therapy.
  2. Calculate current opioid requirement.
  3. Convert the opioid using table above.
  4. ASSESS! Combine Steps 1-3 to determine what is most appropriate clinically.  If the patient is suffering from severe pain, using the calculated dose may be appropriate.  If the patient is requesting a switch but is otherwise pain controlled, consider a general dose reduction of 25-50% in the new opioid.
  5. Monitor the patient for efficacy and side effects.

 

While online calculators can be helpful, opioid conversions should be done thoughtfully with a full patient assessment to determine the correct conversion for the individual patient.

 

 

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Category: Pharmacology & Therapeutics

Title: Nitroglycerin Drug-Drug Interactions

Keywords: nitroglycerin, hypotension, PDE5 inhibitors (PubMed Search)

Posted: 10/3/2020 by Ashley Martinelli
Click here to contact Ashley Martinelli

Nitroglycerin is a potent vasodilator used most commonly for the treatment of angina and ACS.  It can also be administered as a continuous infusion for acute management of a hypertensive emergency or sympathetic crashing acute pulmonary edema.  

 

Most are aware of asking men for history of medications for erectile dysfunction (PDE5 inhibitors: sildenafil, tadalafil, vardenafil) but many overlook the fact that men and women may be on these medications chronically for pulmonary hypertension. Men can also be on these medications for the treatment of BPH. Be broad in your history taking and do not limit the discussion to erectile dysfunction or a specific gender.

 

Drug interaction:

-PDE5 inhibitors prevent the breakdown of cGMP

-Nitrates are nitric oxide donors that increase the production of cGMP

-The combination can lead to excessive vasodilation

 

If accidentally co-administered:

There is no antidote for this medication error.  Support the patient with Trendelenburg positioning, fluid administration, and if needed, vasopressors such as norepinephrine until blood pressure stabilizes.

 

How long should you wait to administer nitrates after a patient takes a PDE5 Inhibitor?

Sildenafil and vardenafil: 24 h after last dose*

Tadalafil > 48 h after last dose*

*Even if acute ACS event

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Category: Pharmacology & Therapeutics

Title: Esmolol for Refractory Ventricular Fibrillation (VF) or Pulseless Ventricular Tachycardia (VT)

Keywords: esmolol, cardiac arrest, ventricular tachycardia, ventricular fibrillation (PubMed Search)

Posted: 9/5/2020 by Ashley Martinelli (Updated: 3/18/2024)
Click here to contact Ashley Martinelli

Patients with cardiac arrest due to VF/VT have a higher likelihood of survival compared to those with unshockable rhythms.  Unfortunately some will still not survive even with following the AHA/ACLS algorithms leading to “refractory VF/VT.”  The survival rate of refractory VF/VT is 3-15%, with poor neurologic outcomes. 
 
Esmolol has been proposed as a treatment for the electrical storm of VF/VT to counteract the deleterious effect of beta receptor stimulation by epinephrine.
 
A recent meta-analysis of 3 trials of beta-blockade vs control patients for refractory VF/VT found:
 
Beta-blockade
N=22
Control
N= 44
OR/CI
Temporary ROSC, n (%)
19 (86.4)
14 (31.8)
OR 14.46, 95% CI 3.63-57.57
Sustained ROSC, n (%)
13 (59.1)
10 (22.7)
OR 5.76, 95% CI 1.79-18.52
Survival with neurological function, n (%)
6 (27.3)
4 (9.1)
OR 4.42; 95% CI 1.05-18.56
 
Takeaway: Esmolol needs to be studied further in prospective trials, but may be reasonable to attempt in refractory VF/VT.
 
Esmolol products:
§  Esmolol vial: 10 mg/mL (10mL)
o   Vial strength listed in mg, not mcg
o   Can cause complications with calculations, especially in high risk code scenario
§  Conversion of mg à mcg weight à based calculation 500mcg/kg
§  Do not ask anyone to do this calculation during a code!
§  Esmolol pre-made infusion: 2500 mg/250mL
o   Pump is set up to deliver weight based doses in mcg/kg
o   No mental math required!
 
How to do it at UMMC to limit mistakes in calculation:
1.       Obtain an esmolol pre-made infusion bag
2.       Program the pump for 50 mcg/kg/min continuous infusion (this is a required step in pump programming)
3.       Program the pump to give a 500 mcg/kg bolus x 1
4.       Permit the background infusion to run
5.       Can give an additional bolus of 500 mcg/kg x 1 and increase rate to 100 mcg/kg/min depending on clinical response

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Category: Pharmacology & Therapeutics

Title: Safe Opioid Use in Renal Failure

Keywords: opioid, renal failure, dialysis (PubMed Search)

Posted: 7/6/2020 by Ashley Martinelli (Updated: 3/18/2024)
Click here to contact Ashley Martinelli

Pain management can be challenging in patients with acute or chronic renal failure.  Opioid medications should always be used with caution, but some are safer than others.  Morphine and codeine specifically should be avoided in these patients due to accumulation of active metabolites that can prolong the duration of effect and adverse events. 

Opioid

Renal Failure Impacts

Renal Failure Recommendation

Dialysis Recommendation

Morphine

Active metabolites accumulate

no

no

Codeine

Active metabolites accumulate

no

no

Hydromorphone

Minimal active metabolites

yes

yes

Oxycodone

Minimal active metabolites

yes

yes

Fentanyl

No active metabolites

yes

yes

Methadone

Active metabolites are inactive

yes

yes

 

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Short periods of AKI have been linked to prolonged hospitalizations, development of CKD/ESRD and in-hospital mortality.  Historically, AKI in the ED has been studied with respect to the receipt of contrast media with little data available on nephrotoxic medications.

A recent 5-year retrospective cohort study sought to determine the impact of prescribing nephrotoxic medications in the ED and the development of AKI within 7 days defined as an increase in SCr of ≥ 0.3 mg/dL or 1.5 x baseline.  The categories of potentially nephrotoxic medications included ACE-i/ARB, antibiotics, diuretics, NSAIDs, and other (antifungal, antineoplastic, and antivirals).

Inclusion: Adult patients ≥ 18 years, with an initial and repeat SCr measured 24-168h after the initial test, under admitted or observation status (discharged patients were included if they had a repeat SCr in the time window).

Exclusion: previous hospital or ED visit within 7 days, initial SCr < 0.4 mg/dL, initial SCr > 4.0 mg/dL, missing data, dialysis, or transplant history.

The authors assessed 46,965 hospitalized encounters and found that 13.8% of patients developed AKI.  Risk factors included older age, African American patients, history of CHF or CKD, higher initial SCr, and higher complexity and mortality.  AKI developed within 48 hours in half of the patients and the reminder did so by 120 hours.  Approximately 22% had ≥ 1 potentially nephrotoxic medication administered and 6% had ≥ 2 classes.

Diuretics were associated with the highest risk of AKI (64% increased risk), followed by ACE-i/ARBs (39%), and antibiotics (13%).  NSAIDs were not associated with an increased risk. The antibiotics associated with the highest risk of AKI were piperacillin-tazobactam, sulfamethoxazole-trimethoprim, and quinolones.

Bottom Line: Medications prescribed in the ED have an impact on the development of AKI during hospitalization.  While these cannot always be avoided, use caution when combining multiple nephrotoxic medications and discontinue therapy early when feasible.

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Category: Pulmonary

Title: Community-Acquired Pneumonia Guideline Update

Keywords: CAP, Pneumonia (PubMed Search)

Posted: 2/1/2020 by Ashley Martinelli (Updated: 3/18/2024)
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: Pharmacology & Therapeutics

Title: Adenosine Administration

Keywords: adenosine, SVT (PubMed Search)

Posted: 12/8/2019 by Ashley Martinelli (Updated: 3/18/2024)
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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Category: Pharmacology & Therapeutics

Title: The Return of Droperidol

Keywords: droperidol (PubMed Search)

Posted: 9/7/2019 by Ashley Martinelli (Updated: 3/18/2024)
Click here to contact Ashley Martinelli

Droperidol is a butyrophenone with primary action as a dopamine D2 receptor antagonist.  Historically, it has been used to treat a variety of conditions from nausea and headaches to acute agitation.  In 2001, the FDA issued a black box warning for risk of cardiac arrhythmias. Following this warning, droperidol was on national shortage for several years, further limiting its use.

Several months ago, droperidol returned to the US market and is available at some institutions. Below is a refresher on dosing and monitoring.  Similar to haloperidol, droperidol can cause extrapyramidal symptoms. Consider pre-treatment with diphenhydramine.

Dosing Recommendations:

Nausea and vomitting: 1.25 mg IV

Headache: 2.5 mg IV, 5 mg IM

Acute agitation: 5mg IM/IV

QTc prolongation is still a concern, especially at higher doses. If using doses > 2.5mg, or using repeated doses, obtain an ECG to ensure safe use of this medication. If the QTc is greater than 440 msec for males or 450 msec for females, droperidol is not recommended.  There is little data regarding the risk with lower doses. Utilize clinical judgement and assess patient risk factors.

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Category: Airway Management

Title: Fixed Dose PCC for Warfarin-Associated Critical Bleeding

Keywords: prothrombin complex concentrate, warfarin, bleeding (PubMed Search)

Posted: 5/29/2019 by Ashley Martinelli (Emailed: 6/1/2019) (Updated: 6/1/2019)
Click here to contact Ashley Martinelli

For patients with bleeding due to warfarin, prothrombin complex concentrate (PCC) is the recommended antidote. Historically, PCC has been dosed on weight and INR:

·         INR 2 - 4: 25 units/kg, max 2500 units

·         INR 4 - 6: 35 units/kg, max 3500 units

·         INR > 6: 50 units/kg, max 5000 units

New data demonstrates that fixed dosing offers several advantages with similar efficacy outcomes:

·         Standardized dosing

·         Improved time to administration

·         Decreased cost

The University of Maryland Health System has adopted a fixed dose strategy for all patients with warfarin-associated critical bleeding:

·         Bleeding site other than intracranial hemorrhage AND INR 1.4 - 6 AND weight ≤ 100 kg = 1500 units

·         Intracranial hemorrhage OR > 100 kg OR INR >6 = 2000 units

**Note: PCC is also the antidote of choice for reversing critical bleeding due to factor Xa inhibitors (rivaroxaban, apixaban, edoxaban).  All critical bleeds due to these agents should receive 50 units/kg, max 5000 units.

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Category: Pharmacology & Therapeutics

Title: Managing Patients on Continuous Home Infusion Medications

Keywords: Milrinone, dobutamine, insulin, pumps (PubMed Search)

Posted: 5/4/2019 by Ashley Martinelli (Updated: 3/18/2024)
Click here to contact Ashley Martinelli

Continuous home infusion therapies of medications such as insulin, milrinone, dobutamine, and pulmonary hypertension medication such as treprostinil are becoming more common.  As a result, you may see these patients present to the emergency room and need to know the basics for checking the pump.

  • Is the pump working correctly?
    • Check the infusion lines for leaks or holes
    • Is the screen on, and does it show the correct dose information
  • How long will the current battery last?
  • How long will the current infusion bag last or expire?
    • Also consider the half-life of the medication. Infusions for pulmonary hypertension have a very short half-life and cannot be stopped abruptly.
  • Is the medication carried by the hospital or will the patient need to provide their own medication for pump refills?
  • What is the current dose?
    • Look for doses in weight based increments (i.e. mcg/kg/min, or ng/kg/min)
    • Insulin may have a basal rate and a bolus dose.
  • What is the patient's "dosing weight"?
    • Ensure that the weight used to program the pump is the same weight used to enter a continuation order in the electronic medical record. This may be different from their current weight and can lead to dose changes if not done properly.
  • What is the current bag concentration?

These questions are very important to determine if you will need to order a replacement infusion bag and run it on a hospital infusion pump, or if the patient can safely remain on their pump during the initial medical evaluation. 

 



Category: Pharmacology & Therapeutics

Title: TXA Quick Review (submitted by Kortney Morrell, PharmD)

Keywords: bleeding, epistaxis, tranexamic acid (PubMed Search)

Posted: 3/2/2019 by Ashley Martinelli (Updated: 3/18/2024)
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Mechanism of Action 

Tranexamic Acid (TXA) is an antifibrinolytic agent that is a competitive inhibitor of plasminogen activation, and a non-competitive inhibitor of plasmin 

Inhibits the breakdown of fibrin mesh allowing clot formation

  • Vial Concentration: 1000mg/10 mL 

When is it Indicated? 

Epistaxis/Oral Bleeds/Fistula Bleeds

  • Local application of injectable form of TXA 
  • Dose: Gauze soaked with 500 mg (5 mL) applied topically to the site of bleeding 

Trauma

  • Criteria for use: Significant hemorrhage or significant risk of hemorrhage in adult trauma patients (SBP <90 mmHg and/or HR >110 bpm) 
  • Dose: 1g in 100 mL 0.9% NaCl infused over 10 minutes followed by 1g in 100 mL 0.9% NaCl over 8 hours 

Adverse Reactions 

  • Generally well tolerated
  • GI Disturbances: nausea, vomiting, diarrhea 
  • Thrombotic Events 
  • Hypersensitivity reactions: anaphylaxis and anaphylactoid reactions 
  • Hypotension following rapid injection (maximum rate is 100 mg/minute)