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PEM POCUS Series: Intussusception

Read this tutorial on the use of point of care ultrasonography (POCUS) for pediatric intussusception. Then test your skills on the ALiEMU course page to receive your PEM POCUS badge worth 2 hours of ALiEMU course credit.

 

Take the ALiEMU PEM POCUS: Intussusception Quiz – test your skills

PATIENT CASE

Johnny is a 2-year-old boy who comes into the emergency department for abdominal pain for the last day. His parents are concerned that he has been having intermittent abdominal pain and has seemed very tired all day. Parents deny bloody stool.

On arrival, his vital signs are:

Vital SignFinding
Temperature36.9C
Heart rate110 bpm
Blood pressure97/50
Respiratory rate22
Oxygen saturation (room air)99%

He is tired appearing, and his abdominal exam is soft but diffusely tender. Given his intermittent abdominal pain, you decide to perform an intussusception point of care ultrasound (POCUS) exam.

ULTRASOUND TECHNIQUE

Intussusception is when one part of the bowel telescopes, or gets stuck, in another part of the bowel. Typically intussusception refers to ileocolic intussusception where the ileum becomes stuck in the colon. To perform the ultrasound, start in the right lower quadrant and trace the colon. See below for a step-by-step technique.

intussusception
Overview of sequential ultrasound transducer positioning on the anterior abdomen to assess for intussusception

Technique

  • The patient should be positioned supine.
  • To aid in comforting the child, the child can be positioned supine in the parent’s lap while undergoing the scan. Having the parent or another provider offer a toy, book, or phone/tablet to distract the child during the scan can also help ease anxiety.
  • Begin in the right lower quadrant (RLQ), using a high frequency linear probe with the probe marker to patient’s right.
  • First, identify the anatomical landmarks in the RLQ (see ultrasound images below):
    • Psoas muscle (green) laterally
    • Right iliac vessels (blue)
    • Abdominal muscles (red)
    • Bladder (yellow) medially

Ultrasound image: Anterior Abdomen (RLQ) View

intussusception RLQ ultrasound

Ultrasound Image: Anterior Abdomen RLQ (More Medial) View

PEM POCUS intussusception RLQ More Medial
  • Perform graded compression, with slow steady pressure to displace bowel gas
  • Follow the colon from the RLQ to right upper quadrant (RUQ) until the liver (purple) and gallbladder are identified

Ultrasound Image: Anterior Abdomen (RUQ) View

PEM POCUS intussusception RUQ
  • Rotate the probe marker to patient’s head and scan the entire length of the transverse colon.
  • Rotate the probe marker back to patient’s right and scan the entire length of the descending colon, making sure to scan all four quadrants.
  • Save representative video clips and still images of each quadrant.
  • If an intussusception is found, measure its diameter in transverse view and note in which quadrant(s) it is found.
  • At the end of scan, if you have found an intussusception, re-image the abdomen to make sure it was not transient.
  • The provider should maintain awareness of the patient’s comfort throughout the scan.

INTUSSUSCEPTION CLASSIC FINDINGS

Normal (no intussusception)

Normal: There is no target or sandwich sign, but rather just folded normal bowel. (To replay, press circular arrow in bottom left corner)

Abnormal findings

  • Look for findings of a sandwich sign (or pseudo-kidney sign) in the longitudinal view and target sign (or donut sign) in the transverse view.
  • If visualized, measure the diameter of the intussusception in short axis (transverse) and note which in which quadrant(s) it is located.

Sandwich

Anterior abdomen ultrasound: Intussusception – Presence of a sandwich sign (long axis view) and target sign (short axis view)

Target Sign

Intussusception diameter ultrasound
Measurement: The diameter of an intussusception (i.e., target sign) in transverse view involves measuring the distance from outer wall to outer wall.

Additional Anterior Abdominal Ultrasound Videos

Pro Tip
It can be difficult to distinguish intussusception of the small bowel-small bowel (i.e., when the ileum or part of the small bowel telescopes into itself) versus ileocolic (i.e., when the ileum becomes telescopes into the colon). The former often does not require a procedure for reduction, while the latter typically does. If the target sign diameter is <2 cm and transient, a small bowel-small bowel intussusception should be suspected. The length of the intussusception, or how many quadrants are involved, can also be measured for an idea of how much bowel is involved.

Small bowel-small bowel intussusception

Small bowel-small bowel intussusception – Note the small size of the target lesion. Because the ultrasound video scans to a depth of 3.3 cm (see bottom right side of the screen), the target sign appears to be approximately only 1 cm in diameter.

 

Small bowel-small bowel intussusception – There is a target sign, but it is small (<2 cm) with a small fat (white) core.

 

Ileo-colic intussusception

Ileo-colic intussusception with classic target sign – Note the lymph nodes (black) inside the mesenteric fat (white) in the center of the target.

FACTS and LITERATURE REVIEW

Mimickers of Intussusception

There are additional pathologies that can be mistaken for intussusception such as an intussuscepted appendix, appendicitis surrounded by abscess, and Meckel’s diverticulum, which are beyond the scope of this course. Any concerning finding for intussusception should be followed by a confirmatory study by the radiology department.

Benefits of intussusception POCUS scans

Although few studies have looked at point of care ultrasonography (POCUS) for intussusception, the existing studies have shown excellent test characteristics and a decreased length of stay with using POCUS.

Two studies assessed the test characteristics of the intussusception POCUS.

PublicationStudy MethodologySensitivitySpecificity
Riera et al. (2012)​1​This journal publication was a prospective study of 82 patients who underwent POCUS by pediatric emergency medicine (PEM) providers. The gold standard was a comprehensive radiology ultrasound.85%97%
Trigylidas et al. (2017) ​2​This abstract reported a retrospective study of 105 intussusception POCUS scans by PEM providers. The gold standard was either a direct radiology over-read of the POCUS scans or a radiology department ultrasound.96.2%92.6%
Lin-Martore et al. (2020)6This systematic review and meta analysis included 1,303 patients and 6 studies.94.9%99.1%
Bergmann et al. (2021)7This prospective study of 256 children across 17 sites (35 sonologists) compared POCUS and radiology performed ultrasound using a gold standard of clinically important intussusception which was defined as an intussusception that required radiographic or surgical reduction during or within 7 days of the incident ED visit.96.6%98%

In terms of ED length of stay (LOS), Kim et al. (2017) reported that after the introduction of an intussusception POCUS scanning protocol, the LOS decreased by >200 minutes.​3​

Differentiating small bowel-small bowel from ileocolic intussusception

In general, true ileocolic intussusceptions are:

  • Found on the right side of the abdomen
  • >2 cm in diameter
  • Have mesenteric fat (which is white) and lymph nodes in the center
  • Do not self resolve

There have been studies looking at distinguishing small bowel-small bowel from ileocolic intussusception. These, however, have been radiology-based and not POCUS studies, making generalizability to the ED setting challenging. Thus, if there is a concern for an intussusception, a radiology ultrasound should be ordered.

One small study with 27 patients by Wiersma et al. (2006) found that small bowel-small bowel intussusceptions had a smaller mean diameter and length compared to ileocolic intussusceptions.​4​

Type of intussusception# of patients and scansMean diameter (range)Mean length (range)Location
Small bowel-small bowel10 patients, 11 scans1.5 cm (1.1-2.5 cm)2.5 cm (1.5-6 cm)Distributed throughout the abdomen (6 paraumbilical, 2 RUQ, 2 RLQ, 1 LLQ)
Ileocolic14 patients, 16 scans3.7 cm (3-5.5 cm)8.2 cm (5-12.5 cm)All on right side of abdomen

Lioubashevsky et al 2013​5​ had a larger sample size (174 patients) with similar findings. The authors also measured the ratio of the inner fat core to the intussusception outer wall and identified the presence or absence of lymph nodes within the lesion.

Type of Intussusception# of patientsMean diameter (range)Mean length (range)Ratio of fat core to the intussusception outer wall% of patients with lymph nodes in the lesion
Small bowel-small bowel57 patients1.4 cm 
(1.1-2.5 cm)		2.5 cm 
(1.5-6 cm)		<114%
Ileocolic143 patients2.6 cm 
(1.3-4 cm)		8.2 cm 
(5-12.5 cm)		>189.5%

References [click to expand] +

  1. Riera A, Hsiao A, Langhan M, Goodman T, Chen L. Diagnosis of intussusception by physician novice sonographers in the emergency department. Ann Emerg Med. 2012;60(3):264-268. PMID 22424652
  2. Trigylidas TE, Kelly JC, Hegenbarth MA, Kennedy C, Patel L, O’Rourke K. 395 Pediatric Emergency Medicine-Performed Point-of-Care Ultrasound (POCUS) for the Diagnosis of Intussusception. Annals of Emergency Medicine. October 2017:S155. DOI
  3. Kim J, Lee J, Kwon J, Cho H, Lee J, Ryu J. Point-of-Care Ultrasound Could Streamline the Emergency Department Workflow of Clinically Nonspecific Intussusception. Pediatr Emerg Care. September 2017. PMID 28926507
  4. Wiersma F, Allema J, Holscher H. Ileoileal intussusception in children: ultrasonographic differentiation from ileocolic intussusception. Pediatr Radiol. 2006;36(11):1177-1181. PMID 17019589
  5. Lioubashevsky N, Hiller N, Rozovsky K, Segev L, Simanovsky N. Ileocolic versus small-bowel intussusception in children: can US enable reliable differentiation? Radiology. 2013;269(1):266-271. PMID 23801771
  6. Lin-Martore M, Kornblith AE, Kohn MA, Gottlieb M. Diagnostic Accuracy of Point-of-Care Ultrasound for Intussusception in Children Presenting to the Emergency Department: A Systematic Review and Meta-analysis. West J Emerg Med. 2020 Jul 2;21(4):1008-1016. doi: 10.5811/westjem.2020.4.46241. PMID: 32726276.
  7. Bergmann KR, Arroyo AC, Tessaro MO, et al; P2Network. Diagnostic Accuracy of Point-of-Care Ultrasound for Intussusception: A Multicenter, Noninferiority Study of Paired Diagnostic Tests. Ann Emerg Med. 2021 Jul 2:S0196-0644(21)00340-1. doi: 10.1016/j.annemergmed.2021.04.033. Epub ahead of print. PMID: 34226072.

Case Resolution

You place a linear, high-frequency probe on the right side of the patient’s abdomen. You perform a bedside ultrasound scan, viewing transversely and longitudinally through the upper and lower abdomen. You observe the following:

What is the diagnosis?

This is an intussusception!

The intussusceptum (red) is the part of the bowel that has telescoped into the intussuscipiens (blue). When ileum becomes trapped in the colon, this can lead to ischemia and necrosis over time. This is what causes the classic “currant jelly stools”, which are bloody stools.

Tip: The classic triad of colicky abdominal pain, palpable mass and bloody stool are present in less than 50% of patients, and intussusception should be suspected for patients with vomiting, abdominal pain, and/or lethargy.​1​

Hospital course

Johnny underwent an air enema reduction in the Radiology department, which successfully reduced the ileocolic intussusception.

Reference

  1. Daneman A, Alton D. Intussusception. Issues and controversies related to diagnosis and reduction. Radiol Clin North Am. 1996;34(4):743-756. PMID 8677307.
Take the ALiEMU PEM POCUS: Intussusception Quiz – test your skills

The PEM POCUS series was created by the UCSF Division of Pediatric Emergency Medicine to help advance pediatric care by the thoughtful use of bedside ultrasonography.

Learn more about bedside ultrasonography on the ALiEM Ultrasound for the Win series

By |2021-10-21T16:59:09-07:00May 10, 2021|Gastrointestinal, PEM POCUS, Ultrasound|
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Bupropion Overdose: Factors Associated with Seizures

Background

Bupropion ingestions are one of the scarier poisonings due to a relatively narrow therapeutic index and the numerous adverse effects that may occur. Medical toxicologist Dr. Dan Rusyniak details his hatred of this drug in overdose in a Tox & Hound blog post aptly-titled Illbutrin. When bupropion was first approved in the 1980s, the max dose was 600 mg/day [1]. However, reports of seizures, particularly in patients with bulimia, caused its temporary removal from the market [2]. It was reintroduced a few years later with a max dose of 450 mg/day [3]. Common signs and symptoms noted in overdose include seizures, agitation, sinus tachycardia, and QRS/QTc prolongation. Seizures occur in up to 40% of overdose cases, are often refractory to initial therapy, and can happen as long as 24 hours after an overdose with extended release formulations [4, 5].

Evidence

A study of 256 patients from the Toxicology Investigators Consortium (ToxIC) Registry identified three factors associated with seizure development after bupropion overdose [6, 7].

  1. QTc prolongation > 500 msec (OR = 3.4, 95% CI: 1.3-8.8)
  2. Tachycardia (heart rate > 140) (OR = 1.9, 95% CI: 1-3.6)
  3. Age 13–18 years (OR = 2.4, 95% CI: 1.3-4.3)

Agitation and tremors are more common in patients who develop seizures with bupropion compared to those who do not [4]. Additionally, presence of tachycardia (heart rate >100 bpm) has a sensitivity of 91% and a negative predictive value of 93% for development of seizures [4].

Bottom Line

  • Seizures are common following bupropion overdose and patients who seize are generally tachycardic.
  • Patients should be observed at least 24 hours after a extended release bupropion overdose, as seizures can be significantly delayed.

Want to learn more about EM Pharmacology?

Read other articles in the EM Pharm Pearls Series and find previous pearls on the PharmERToxguy site.

References

  1. Davidson J. Seizures and bupropion: a review. J Clin Psychiatry. 1989;50(7):256-261. PMID: 2500425.
  2. Horne RL, Ferguson JM, Pope HG, et al. Treatment of bulimia with bupropion: a multicenter controlled trial. J Clin Psychiatry. 1988;49(7):262-266. PMID: 3134343.
  3. Huecker MR, Smiley A, Saadabadi A. Bupropion. In: StatPearls. StatPearls Publishing; 2021. Available from: https://www.ncbi.nlm.nih.gov/books/NBK470212/.
  4. Starr P, Klein-Schwartz W, Spiller H, Kern P, Ekleberry SE, Kunkel S. Incidence and onset of delayed seizures after overdoses of extended-release bupropion. Am J Emerg Med. 2009;27(8):911-915. doi: 10.1016/j.ajem.2008.07.004. PMID: 19857406.
  5. Al-Abri SA, Orengo JP, Hayashi S, Thoren KL, Benowitz NL, Olson KR. Delayed bupropion cardiotoxicity associated with elevated serum concentrations of bupropion but not hydroxybupropion. Clin Toxicol (Phila). 2013;51(10):1230-1234. doi: 10.3109/15563650.2013.849349. PMID: 24131328.
  6. Wax PM, Kleinschmidt KC, Brent J, ACMT ToxIC Case Registry Investigators. The toxicology investigators consortium (Toxic) registry. J Med Toxicol. 2011;7(4):259-265. doi: 10.1007/s13181-011-0177-z. PMID: 21956161.
  7. Rianprakaisang TN, Prather CT, Lin AL, Murray BP, Hendrickson RG, Toxicology Investigators Consortium (ToxIC). Factors associated with seizure development after bupropion overdose: a review of the toxicology investigators consortium. Clin Toxicol (Phila). Published online April 21, 2021:1-5. doi: 10.1080/15563650.2021.1913180. PMID: 33878992.
By |2021-05-04T11:49:11-07:00May 8, 2021|EM Pharmacy Pearls, Neurology, Tox & Medications|
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ALiEM AIR Series | HEENT 2021 Module

This image has an empty alt attribute; its file name is AIR-logo-2016-transparent-SAEM-CORD-586x650.jpg

Welcome to the AIR HEENT Module! After carefully reviewing all relevant posts from the top 50 sites of the Social Media Index, the ALiEM AIR Team is proud to present the highest quality online content related to head, eyes, ears, nose, and throat emergencies in the Emergency Department. 6 blog posts within the past 12 months (as of March 2021) met our standard of online excellence and were curated and approved for residency training by the AIR Series Board. We identified 2 AIR and 4 Honorable Mentions. We recommend programs give 3 hours (about 30 minutes per article) of III credit for this module.

AIR Stamp of Approval and Honorable Mentions

 

In an effort to truly emphasize the highest quality posts, we have 2 subsets of recommended resources. The AIR stamp of approval is awarded only to posts scoring above a strict scoring cut-off of ≥30 points (out of 35 total), based on our scoring instrument. The other subset is for “Honorable Mention” posts. These posts have been flagged by and agreed upon by AIR Board members as worthwhile, accurate, unbiased, and appropriately referenced despite an average score.

 

Take the AIR HEENT quiz at ALiEMU

Interested in taking the HEENT quiz for fun or asynchronous (Individualized Interactive Instruction) credit? Please go to the above link. You will need to create a free, 1-time login account.

Highlighted Quality Posts: HEENT Emergencies

SiteArticleAuthorDateLabel
EMCritEpiglottitisJosh Farkas, MDJuly 2, 2020AIR
Taming the SRUJaw DislocationKristin Meigh, MDJanuary 13, 2021AIR
EMDocsPeritonsillar AbscessRyan Sumpter, MD and Rachel Bridwell, MDMar 7, 2020HM
PedEMMorselsOpen Globe Injuries in ChildrenSean Fox, MDAugust 14, 2020HM
PedEMMorselsNasolacrimal Duct ObstructionSean Fox, MDJune 12, 2020HM
St. Emlyn’sLudwig’s AnginaPete Hulme, MBChBJanuary 9, 2021HM

(AIR = Approved Instructional Resource; HM = Honorable Mention)

If you have any questions or comments on the AIR series, or this AIR module, please contact us! More in-depth information regarding the Social Media Index.

Thank you to the Society of Academic Emergency Medicine (SAEM) and the Council of EM Residency Directors (CORD) for jointly sponsoring the AIR Series! We are thrilled to partner with both on shaping the future of medical education.

By |2021-05-08T04:07:06-07:00May 7, 2021|Approved Instructional Resources (AIR series), HEENT|
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SplintER Series: What is Wrong With My Daughter?

 

A 16 year-old competitive gymnast presents to the emergency department with left ankle pain for several weeks and missed periods. The mother provides consent to treat the patient and informs you she is concerned that with the patient’s missed periods, she may be pregnant. You obtain x-rays of her ankle (Figure 1).

Figure 1. Case courtesy of Dr Hani Makky ALSALAM, Radiopaedia.org, rID: 8720

 

Stress fracture at the distal tibial metaphysis – note the faint sclerotic line at the tibial metaphysis (Figure 2).

Figure 2. Arrows identifying the stress fracture. Case courtesy of Dr. Hani Makky Al Salam, Radiopaedia.org, rID: 8720

When coupled with the amenorrhea, consider the female athlete triad.

  • PEARL: The female athlete triad is a syndrome consisting of disordered eating, amenorrhea, and low bone mineral density (eg. osteoporosis) – Patients will have a degree of dysfunction from all 3 of the components. This is a fairly common disorder in young female athletes but the actual prevalence is hard to estimate because of the complexity of the three components [1]. Studies have shown a range from 0-16% when encompassing all three but can be as high as 4-18% when using two concurrent components and even 16-54% when only looking for one [2,3].

  • PEARL: Stress fractures in competitive athletes is usually multifactorial – increased activity, poor nutrition, and possible hormone imbalance [4,5].

Plain film ankle views should be obtained. If a stress fracture is acute, sensitivity on plain films can be as low as 10% [6]. MRI can be performed outpatient with a sensitivity approaching 100% [4,5,7,8]. A pregnancy test should be performed as well given the amenorrhea. A standard workup for amenorrhea should be performed as an outpatient. Inquire about eating habits and anxiety/depression.

  • PEARL: Athletes, regardless of competition level and gender, may be pushed into decreasing caloric intake for the sake of performance, appearance, or making weight. This can have serious physical and mental implications.

The three components of the female triad are on a spectrum of severity in the disruption of bone mineral density/osteoporosis, menstrual dysfunction/dysmenorrhea, and low energy with or without an eating disorder [1,9-11]. Patients will have a degree of dysfunction of all three components.

  • PEARL: Risk factors for developing the female athlete triad are participation in sports that emphasize leanness or a specific weight, appearance, or are beneficial if less gravitational forces. These may include gymnastics, ice skating, wrestling, boxing, dance, and track [10,12].

Stress fracture treatment included rest and analgesics. Immobilization is not necessary, but refraining from activity which exacerbates pain is crucial. NSAIDs may be used for pain control [5,7]. Female athlete triad is multifactorial and outpatient follow up should be ensured. Referral to adolescent medicine, sports medicine, or close primary care follow up is important.

  • PEARL: The patient will need education on good eating habits and nutrition, decrease in activity, and counseling [1,10,12]. The best way to treat the female athlete triad is to prevent it.

Check out ALiEM’s SplintER Series to brush up on other can’t miss diagnoses of ankle pain.

References

  1.  Weiss Kelly AK, Hecht S; COUNCIL ON SPORTS MEDICINE AND FITNESS. The Female Athlete Triad. Pediatrics. 2016;138(2):e20160922. PMID: 27432852.
  2. Nichols JF, Rauh MJ, Lawson MJ, Ji M, Barkai HS. Prevalence of the female athlete triad syndrome among high school athletes. Arch Pediatr Adolesc Med. 2006;160(2):137-142. doi:10.1001/archpedi.160.2.137. PMID: 16461868.
  3. Hoch AZ, Pajewski NM, Moraski L, et al. Prevalence of the female athlete triad in high school athletes and sedentary students. Clin J Sport Med. 2009;19(5):421-428. doi:10.1097/JSM.0b013e3181b8c136. PMID: 19741317.
  4. Matcuk GR Jr, Mahanty SR, Skalski MR, Patel DB, White EA, Gottsegen CJ. Stress fractures: pathophysiology, clinical presentation, imaging features, and treatment options. Emerg Radiol. 2016;23(4):365-375. PMID: 27002328.
  5. Saunier J, Chapurlat R. Stress fracture in athletes. Joint Bone Spine. 2018;85(3):307-310. PMID: 28512006.
  6. Matheson GO, Clement DB, McKenzie DC, Taunton JE, Lloyd-Smith DR, MacIntyre JG. Stress fractures in athletes. A study of 320 cases. Am J Sports Med. 1987;15(1):46-58. doi:10.1177/036354658701500107. PMID: 3812860.
  7. Denay KL. Stress Fractures. Curr Sports Med Rep. 2017;16(1):7-8. PMID: 28067732.
  8. McInnis KC, Ramey LN. High-Risk Stress Fractures: Diagnosis and Management. PM R. 2016;8(3 Suppl):S113-S124. PMID: 26972260.
  9. Otis CL, Drinkwater B, Johnson M, Loucks A, Wilmore J. American College of Sports Medicine position stand. The Female Athlete Triad. Med Sci Sports Exerc. 1997;29(5):i-ix. PMID: 9140913.
  10. Nattiv A, Loucks AB, Manore MM, et al. American College of Sports Medicine position stand. The female athlete triad. Med Sci Sports Exerc. 2007;39(10):1867-1882. PMID: 17909417.
  11. Sundgot-Borgen J. Risk and trigger factors for the development of eating disorders in female elite athletes. Med Sci Sports Exerc. 1994;26(4):414-419.PMID: 8201895.
  12. Scofield KL, Hecht S. Bone health in endurance athletes: runners, cyclists, and swimmers. Curr Sports Med Rep. 2012;11(6):328-334. PMID: 23147022.

By |2021-04-26T10:06:59-07:00May 3, 2021|Expert Peer Reviewed (Clinical), Orthopedic, SplintER|
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One-Time Vancomycin Doses in the Emergency Department

Background

A previous ALiEM post from 2013 by an EM pharmacist colleague argued the case against one-time vancomycin doses in the ED prior to discharge. The take-home points from this post were:

    1. No evidence that a one-time vancomycin has any benefit
    2. This practice is not recommended by the Infectious Diseases Society of America (IDSA)
    3. May extend the patient’s ED stay by at least an hour for the IV infusion, depending on the dose
    4. Increases the cost of the ED visit (e.g., IV line, medication, RN time)
    5. Pharmacokinetically 1 dose of vancomycin doesn’t make sense
      • Vancomycin 1 gm IV x1 provides sub-therapeutic levels for patients with normal renal function
      • Efficacy is based on overall exposure (e.g., AUC/MIC) achieved with repeated dosing over several days
    6. Subtherapeutic vancomycin concentrations lead to development of resistance

Despite the above points, a one-time dose of vancomycin prior to the patient being discharged on an oral regimen is a common practice [1].

Evidence

As stated above, a single dose of vancomycin is unlikely to provide a therapeutic benefit and may only serve to reassure clinicians. The 2020 consensus guidelines regarding vancomycin monitoring for serious MRSA infections reinforce the recommendation of achieving an AUC0-24/MIC ratio of ≥400, as a ratio <400 increases resistance and has inferior efficacy [2]. Since the AUC is dependent on overall time of exposure plus concentration, a single dose for an average patient with normal renal function is not adequate (Figure 1). The graph below also demonstrates how long it generally takes for vancomycin to reach steady state when patients receive a dose every 8 hours.

 

*The estimated AUC above assumes a 30 yo male that weights 70kg and is 6′ tall with a serum creatinine of 1.0 mg/dL.

A randomized trial conducted at Christiane Care Health System compared patients who received a vancomycin loading dose of 30 mg/kg or 15 mg/kg [3]. Just twelve hours after this initial dose, 34.6% of patients who received 30 mg/kg had vancomycin levels in the therapeutic range (trough >15 mg/L) vs. 3% of patients who received 15 mg/kg (p < 0.01).

Bottom Line

Even large vancomycin loading doses rarely achieve therapeutic levels after one dose. Therefore, if the plan is to discharge, skip the one-time dose altogether and choose an antimicrobial regimen that will be continued in the outpatient setting (e.g., doxycycline or sulfamethoxazole/trimethoprim if concerned for MRSA or cephalexin for most other patients).

Want to learn more about EM Pharmacology?

Read other articles in the EM Pharm Pearls Series and find previous pearls on the PharmERToxguy site.

References

  1. Mueller K, McCammon C, Skrupky L, Fuller BM. Vancomycin use in patients discharged from the emergency department: a retrospective observational cohort study. J Emerg Med. 2015;49(1):50-57. doi: 10.1016/j.jemermed.2015.01.001. PMID: 25802166.
  2. Rybak MJ, Le J, Lodise TP, et al. Therapeutic monitoring of vancomycin for serious methicillin-resistant staphylococcus aureus infections: a revised consensus guideline and review by the american society of health-system pharmacists, the infectious diseases society of america, the pediatric infectious diseases society, and the society of infectious diseases pharmacists. Am J Health Syst Pharm. 2020;77(11):835-864. doi: 10.1093/ajhp/zxaa036. PMID: 32191793.
  3. Rosini JM, Laughner J, Levine BJ, Papas MA, Reinhardt JF, Jasani NB. A randomized trial of loading vancomycin in the emergency department. Ann Pharmacother. 2015;49(1):6-13. doi: 10.1177/1060028014556813. PMID: 25358330.
By |2021-04-29T15:40:57-07:00May 1, 2021|EM Pharmacy Pearls, Infectious Disease, Tox & Medications, Uncategorized|
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Safety and Efficacy of Clevidipine for Acute Blood Pressure Control

Background

Rapid and precise control of blood pressure is vital for patients with a hypertensive emergency or an acute stroke. Commonly, nicardipine is utilized in these situations, with nitroprusside being a less appealing alternative. The most recent AHA/ASA Acute Ischemic Stroke Guidelines, updated in 2019, also recommend clevidipine as a first-line antihypertensive option [1]. Clevidipine is a dihydropyridine calcium channel blockers, similar in mechanism to nicardipine and amlodipine. The main advantage of clevidipine over nicardipine is related to its pharmacokinetics (Table 1). Given its shorter half-life of elimination, clevidipine can be titrated every 1-2 minutes. Additionally, if hypotension does occur, stopping the clevidipine infusion allows blood pressure to rebound quickly.

MedicationOnsetDurationHalf-Life
Clevidipine2-4 mins5-15 mins1-15 mins
Nicardipine10-20 mins1-2 hours2-4 hours
Nitroprusside1-2 mins1-10 mins2 mins

Table 1: Pharmacokinetics of Common Antihypertensive Infusions [Micromedex; Lexicomp]

Evidence

Most studies demonstrate equivalent outcomes between clevidipine and other agents (e.g., nicardipine, nitroprusside, nitroglycerin) [2-5]. The ECLIPSE trial is the largest to assess the safety and efficacy of clevidipine [6]. The authors randomized cardiac surgery patients to clevidipine, nicardipine, nitroprusside, or nitroglycerin and found no difference in the incidence of myocardial infarction, stroke, or renal dysfunction. They noted that mortality was higher in patients receiving nitroprusside vs clevidipine, but equivalent compared to the the other medications. Additionally, clevidipine treated patients had significantly fewer excursions outside the prespecified blood pressure range than patients treated with any of the other agents.

Safety

Clevidipine is formulated in a 20% lipid emulsion and packaged in a glass vial. This causes clevidipine to appear similar to propofol, which could lead to safety issues. Also, care should be taken when using both clevidipine and propofol concomitantly, especially at high doses, as both provide clinically significant amounts of lipids, so triglycerides should be monitored.

Bottom Line

Clevidipine is a safe and effective antihypertensive to use in patients that require rapid and strict blood pressure control, specifically in patients with an aortic dissection or an acute ischemic/hemorrhagic stroke.

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References

  1. Powers WJ, Rabinstein AA, Ackerson T, et al. Guidelines for the early management of patients with acute ischemic stroke: 2019 update to the 2018 guidelines for the early management of acute ischemic stroke: a guideline for healthcare professionals from the american heart association/american stroke association. Stroke. 2019;50(12):e344-e418. doi: 10.1161/STR.0000000000000211. PMID: 31662037.
  2. Allison TA, Bowman S, Gulbis B, Hartman H, Schepcoff S, Lee K. Comparison of clevidipine and nicardipine for acute blood pressure reduction in patients with stroke. J Intensive Care Med. 2019;34(11-12):990-995. doi: 10.1177/0885066617724340. PMID: 28820038.
  3. Rosenfeldt Z, Conklen K, Jones B, Ferrill D, Deshpande M, Siddiqui FM. Comparison of nicardipine with clevidipine in the management of hypertension in acute cerebrovascular diseases. J Stroke Cerebrovasc Dis. 2018;27(8):2067-2073. doi: 10.1016/j.jstrokecerebrovasdis.2018.03.001. PMID: 29627171.
  4. Ulici A, Jancik J, Lam TS, Reidt S, Calcaterra D, Cole JB. Clevidipine versus sodium nitroprusside in acute aortic dissection: A retrospective chart review. Am J Emerg Med. 2017;35(10):1514-1518. doi: 10.1016/j.ajem.2017.06.030. PMID: 28669696.
  5. Brehaut SS, Roche AM. Abstract W P65: Clevidipine Outperforms Other Agents in Emergent Acute Hypertension Treatment in Ischemic Stroke Pre-rt-PA. 2015;46:AWP65. doi: 10.1161/str.46.suppl_1.wp65.
  6. Aronson S, Dyke CM, Stierer KA, et al. The ECLIPSE trials: comparative studies of clevidipine to nitroglycerin, sodium nitroprusside, and nicardipine for acute hypertension treatment in cardiac surgery patients. Anesth Analg. 2008;107(4):1110-1121. doi:10.1213/ane.0b013e31818240db. PMID: 18806012.
By |2021-04-12T11:49:04-07:00Apr 24, 2021|Cardiovascular, EM Pharmacy Pearls, Neurology, Tox & Medications|
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