Posts tagged #ultrasound

Sono Pro Tips and Tricks for Evaluation of Elevated Intracranial Pressure

**Written by:** Emma Greever (NUEM ’25) **Edited by:** Maurice Hajjar, MD (NUEM ’22)
**Expert Commentary by**: John Bailitz, MD

Welcome to the NUEM SonoPro Tips and Tricks Series where Local and National Sono Experts team up to take you scanning from good to great for a particular diagnosis or procedure.

For those new to the probe, we recommend first reviewing the basics in the incredible FOAMed Introduction to Bedside Ultrasound Book, 5 Minute Sono, and POCUS Atlas. Once you’ve got the basics beat, then read on to learn how to start scanning like a Pro!

Did You Know?

Ocular ultrasound is a quick procedure which can be done at the bedside to help differentiate between various ophthalmologic emergencies including retinal detachment, vitreous detachment, vitreous hemorrhage, lens detachment, and presence of foreign bodies. Indications for ocular ultrasound include eye pain, acute changes in vision, eye trauma, and suspicion of elevated intracranial pressure, or if there is swelling of periorbital tissue that inhibits direct visualization of the eye. The one absolute contraindication for ocular ultrasound is any suspicion for globe rupture, as placing any pressure on the globe can worsen extrusion of intraocular contents.

Ocular ultrasound can also be used to evaluate for elevated intracranial pressure (ICP). The optic nerve sheath communicates directly with the subarachnoid space. Cerebrospinal fluid flows between the intracranial space and orbit within the subarachnoid space; therefore, increased intracranial pressure is transmitted to the optic nerve sheath. Elevation of ICP is reflected by dilation of the optic nerve sheath. This can be quantified by measuring optic nerve sheath diameter (ONSD). Dilation of the optic nerve sheath often occurs with anterior bulging of the optic disc, seen as optic disc elevation (ODE) on ultrasound. Bulging of the optic disc is seen as papilledema on fundoscopic exam. Both ONSD and ODE measurements are ways to assess for elevated ICP.

If there is concern for elevated ICP, it is not always possible to do a dilated fundoscopic exam, invasive monitoring, or other imaging such as a CT. Point of care ultrasound (POCUS) allows for quick evaluation. Furthermore, POCUS allows for monitoring dynamic changes in ICP as doing serial fundoscopic exams and CTs is not feasible. It is also less invasive than other intra-cranial monitoring. When comparing ONSD (with a cut-off value of >5 mm) with findings of increased ICP on CT, sensitivity and specificity are 95.6% and 92.3%, respectively.

Beyond the emergency department, where else can a SonoPro scan for increased ICP?:

Aside from patients in the emergency department, POCUS for elevated ICP can be used in critically ill children in the PICU, adults in the Neurocritical ICU, and on the battlefield with handheld ultrasounds in combat medicine. ONSD changes within minutes of ICP changing. Studies have demonstrated that the change in ONSD or ODE is strongly correlated with changes in ICP, implying that POCUS could be used to dynamically detect real-time changes in ICP. In neuro-critically ill children, POCUS cannot replace invasive ICP monitoring but can be used as a screening tool in the ICU for intermittent monitoring of ICP when invasive methods are unavailable. It can allow for accurate dynamic evaluation of ICP, which is important in children with traumatic brain injury as fluctuations are common. Additionally, POCUS can be used in many different environments in which imaging is not readily available, such as on the battlefield or in-flight.

How to scan like a Pro:

Place the head of the bed at 45 degrees.
Apply a large, waterproof transparent film dressing (such as a Tegaderm) over the eye you are going to ultrasound, making sure the eye is closed. Make sure to get as much air out from under the Tegaderm as you can.
Apply a large amount of water-soluble ultrasound gel on top of the dressing.
Using a high-frequency linear probe set to ocular mode, place the probe over the eye with the indicator to the patient’s right. It is important to use very minimal pressure on the eye. To have control over the probe and to be able to make small movements with minimal pressure on the eye, rest the side of your hand on the patient’s cheek or bridge of the nose to stabilize your hand.
Ensure the probe is oriented in the transverse plane.
Tell the patient to look straight forward, to the left or right, up, or down as needed to obtain the best view.
Be sure to scan both eyes when concerned for elevated ICP.

What to Look For:

Identify the following structures: anterior chamber, lens, vitreous, retina, and optic nerve.

Use the rule of 3x5 to measure optic nerve sheath diameter:

Find the posterior aspect of the globe overlying the optic nerve
From that point measure 3 mm posteriorly (point A)
Maximal sheath distension occurs at 3 mm behind the papilla

Measure the diameter of the optic nerve from the second point (point B, 3 mm deep)
- Measure from outer wall to outer wall
- < 5mm is normal, 5-6 mm is indeterminate, >6 mm is elevated

Assess for papilledema – measure optic disc elevation (ODE)
- Measure area between the fundus and dome of the papilla

ODE >0.6 mm predicts presence of fundoscopic optic disc edema (sensitivity 82%, specificity 76%); if using the threshold of 1.00 mm then sensitivity is 73% and specificity 100%

This sign can take a couple days to develop and may not appear at the same time as elevated ocular disc diameter

How to interpret:

Determine if ICP is elevated:
- < 5 mm = Likely normal ICP
- >6 mm = Indicates elevated ICP
- Many causes of this, next steps are to identify what is causing the elevation in ICP
- 5-6 mm = Indeterminate range
If elevated, further evaluation for etiology of elevated ICP and treatment of cause.
If indeterminate, assessing for papilledema by measuring the ODE can help in the indeterminate range, although absence of papilledema does not indicate normal ICP.
It is important to note that there is significant variation from person to person regarding ONSD. In other words, >6 mm does not necessarily indicate increased diameter and <5mm does not necessarily mean normal. The SonoPro must use clinical judgement while assessing the ONSD.

Where to Learn More (References)

Where to Learn More (Hyperlinked References):
https://coreem.net/core/ocular-ultrasound/
https://www.coreultrasound.com/onsd/
https://emcrit.org/pulmcrit/pulmcrit-algorithm-diagnosing-icp-elevation-ocular-sonography/
Lin JJ, Chen AE, Lin EE, Hsia SH, Chiang MC, Lin KL. Point-of-care ultrasound of optic nerve sheath diameter to detect intracranial pressure in neurocritically ill children - A narrative review. Biomed J. 2020;43(3):231-239. doi:10.1016/j.bj.2020.04.006
Richards E, Mathew D. Optic Nerve Sheath Ultrasound. [Updated 2021 Jul 31]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan. Available from: https://www.ncbi.nlm.nih.gov/books/NBK554479/
Teismann N, Lenaghan P, Nolan R, Stein J, Green A. Point-of-care ocular ultrasound to detect optic disc swelling. Acad Emerg Med. 2013 Sep;20(9):920-5. doi: 10.1111/acem.12206. PMID: 24050798.
https://www.thepocusatlas.com

Expert Commentary

Thank you for providing this outstanding NUEM Blog Post! Ocular ultrasound for ICP has been a hot topic for over a decade in the EM, PEM, and ICU POCUS literature.

For a full review of my approach to ocular ultrasound, please refer to our 2018 Post - Ocular Ultrasound: From Floaters to Fogginess!

Since that post ,additional literature has been posted questioning the need for Tegaderms over the eye for the reasons we discussed in 2018. Bottomline, if the patient is reliable and can keep their eyes closed for five minutes, then you can skip the Tegaderm. But when the patient is less reliable, then the extra step may still make sense. When locating and measuring the Optic Nerve Sheath (ONS), be absolutely sure to stabilize your hand on the patient's face or forehead particularly when you are over-caffeinated or tired. Then be careful to rock the probe about 15 degrees laterally (illustrated here) to visualize the ONS parallel to the probe’s center US beams, and thereby avoid any edge artifact from visualizing at an angle. Even with the best technique, our local teaching, clinical use, and pilot research has consistently confirmed the need for obtaining multiple measurements of the small optic nerve sheath. Then averaging the best three to obtain the most accurate measurement.

Thank You Dr. Greever (NUEM ’25) and Dr. Hajjar, MD (NUEM ’22) for helping to improve patient care and MedEd through POCUS! Happy scanning everyone.

John Bailitz, MD

Vice Chair for Academics, Department of Emergency Medicine

Professor of Emergency Medicine, Feinberg School of Medicine

Northwestern Memorial Hospital

How To Cite This Post:

[Peer-Reviewed, Web Publication] Greever, E. Hajjar, M. (2024, Sep 11). Sono Pro Tips and Tricks for Evaluation of Elevated Intracranial Pressure. [NUEM Blog. Expert Commentary by Bailitz, J]. Retrieved from http://www.nuemblog.com/blog/sonopro-tips-and-tricks-for-evaluation-of-elevated-intracranial-pressure

Nephrolithiasis: Ultrasonography versus Computed Tomography

**Written by:** Kishan Ughreja , MD (NUEM ‘23) **Edited by:** Ade Akhentuamhen, MD (NUEM ‘21)
**Expert Commentary by**: Tim Loftus, MD, MBA

Journal Club: Ultrasonography versus Computed Tomography for Suspected Nephrolithiasis

A 70-year-old man with BPH s/p TURP, hypertension, hyperlipidemia and stroke presents to the ED with acute onset of intermittent sharp left flank pain radiating into the groin that awoke him from sleep. He endorses nausea without vomiting and denies fever. He also endorses slightly decreased urination with “dribbling.” His urinalysis shows >100 RBC and no signs of infection. Nephrolithiasis is likely high on your differential diagnosis. How do you proceed?

What is your initial imaging test of choice, ultrasound (US) or non-contrast CT, and why?

Would you be satisfied with only US and no follow-up CT?

Would you be confident in a point-of-care-ultrasound evaluation or a formal ultrasound?

Do outcomes for patients with suspected nephrolithiasis differ based on the initial imaging?

Should your medical decision-making change if the patient has a history of nephrolithiasis?

What would you do if the same patient presented again with persistent pain from a previously diagnosed stone?

Pain from suspected nephrolithiasis is a very common complaint in the ED and the incidence of the disease continues to increase. The estimated incidence over the past two decades is up to 340 visits per 100,000 individuals.1 Low-dose non-contrast abdominal CT has become the gold standard for diagnosis as it has become readily available in emergency departments nationwide, with some studies touting sensitivity and specificity of 97% and 95%, respectively.2 However, low dose CT still exposes the patient to radiation and may increase their risk of cancer, as many nephrolithiasis patients often undergo repeat imaging because of recurring pain or urological intervention. Additionally, CT scans prolong average ED lengths of stay. However, with ultrasonography becoming more prevalent in EDs, it may be possible that initial imaging may avoid this radiation risk and still have similar outcomes for patients. Let’s analyze this NEJM article comparing US to CT for the assessment of nephrolithiasis.

Study design: a multicenter, pragmatic, randomized comparative effectiveness trial

Population

N = 2759
ages 18- 76 yo
reported flank or abdominal pain that the treating physician wished to order imaging to establish or rule out a primary diagnosis of nephrolithiasis
not considered at high risk for serious alternative diagnoses e.g. cholecystitis, appendicitis, aortic aneurysm, or bowel disorders
no pregnant patients
no men >129 kg, no women >113 kg
no history of single kidney, renal transplantation, undergoing dialysis

Patient selection

Intervention protocol

patients randomized to 3 groups each using a different initial imaging modality (POCUS vs. Radiology US vs. CT)
patients contacted at 3, 7, 30, 90, and 180 days after randomization to assess study outcomes

Outcome measures

Primary Outcomes

high-risk diagnoses with complications that could be related to missed or delayed diagnoses — within 30 days of ED visit, including:
AAA w/rupture, PNA w/sepsis, appendicitis w/rupture, diverticulitis w/abscess or sepsis, bowel ischemia or perforation, renal infarction, renal stone w/abscess, pyelonephritis w/urosepsis or bacteremia, ovarian torsion w/necrosis, aortic dissection w/ischemia
cumulative radiation exposure from all imaging within 6 months after randomization
total cost (not reported in this study, ongoing analysis)

Secondary Outcomes

serious adverse events (FDA definition)
serious adverse events related to study participation
delayed diagnosis, like acute cholecystitis, appendicitis, bowel obstruction
return ED visits
hospitalizations after being discharged from ED
self-reported pain scores
diagnostic accuracy for nephrolithiasis
by comparing ED diagnosis at discharge to reference standard of confirmed stone by patient’s observation of passage or report of surgical removal

Results

no significant differences among groups in terms of pain scores, medical history, physical exam findings, and ED physician’s assessment of the likelihood of other diagnoses (Table 2)
POCUS and US groups had significantly lower cumulative radiation exposure over 6 months than the CT group (difference attributed to initial ED visit’s imaging choice)
11 patients (0.4%) had high risk diagnoses with complications during first 30 days after randomization, with no significant difference among the 3 groups
no difference when stratified by patients with a history of nephrolithiasis
no significant difference among groups in the number of patients with serious adverse events; total of 466 SAE in 316 patients (91.4% were hospitalizations during f/u period; 26.4% involved surgical treatment of complications of nephrolithiasis)
5 reported deaths (occurred between 38 and 174 days after randomization) — none thought to be related to study participation
the proportion of patients with a confirmed stone diagnosis within 6 months was similar in all 3 groups (POCUS 34.5% vs. US 31.2% vs. 32.7% CT)
diagnostic accuracy based on result of initial imaging modality
- POCUS sensitivity 54% [48 - 60]; specificity 71% [67 - 75]
- US sensitivity 57% [51 - 64]; specificity 73% [69 - 77]
- CT sensitivity 88% [84 - 92]; specificity 58% [55 - 62]

Interpretation

The US group was exposed to less radiation than the CT group and had no significant differences in the incidence of high-risk diagnoses with complications, total serious adverse events, or related serious adverse events.
There also were no significant differences in pain scores, hospitalizations, ED readmissions among the groups.
Many patients in the ultrasound groups did get additional imaging, but this was not the majority.
Patients with a history of nephrolithiasis were less likely to undergo additional imaging with CT if they already had an ultrasound first (31% vs 36%). They did not have poorer outcomes than patients without a history of nephrolithiasis.
Patients only undergoing POCUS and no other testing had a significantly shorter ED stay (1.3 hours)
It is safe to pursue ultrasound as the initial imaging of choice for suspected nephrolithiasis (with additional imaging ordered as necessary at clinical discretion), though it should not necessarily be the only testing performed.

Strengths

large size, diversity in ED settings, randomized design, assessment of clinically important outcomes, a high follow-up rate

Weaknesses

no blinding of investigators, physicians, or patients as this was a pragmatic trial design
independent review was used to characterize serious adverse events related to study participation
strict reference standard for stone diagnosis which was unbiased, but prone to error based on the patient’s memory of self-reporting of stone passage

Internal/external validity

Given the aforementioned strengths of this study and its pragmatic design, these findings appear both internally and externally valid and may be applied to daily clinical practice

Take-Home Points

What is your initial imaging test of choice, ultrasound (US) or non-contrast CT, and why?

Ultrasound is a good choice for initial imaging as most patients do not end up requiring additional imaging during their visit. This leads to reduced cumulative radiation exposure.

Would you be satisfied with only US and no follow-up CT?

In this study, 40.7% of those in the POCUS group and 27% in the formal ultrasound group underwent subsequent CT. Follow up CT should depend on the patient and ultrasound operator. Keep in mind that this study excluded patients with kidney disease, pregnant patients, and obese patients. They also excluded patients who were high risk for other pelvic and abdominal diseases. Lastly the POCUS operators were ED physicians with training “recommended by ACEP.”

Would you be confident in a point-of-care-ultrasound evaluation compared to a formal ultrasound?

Yes. Sensitivity and specificity between these groups were similar.

Do outcomes for patients with suspected nephrolithiasis differ based on the initial imaging?

No. There was no significant difference in subsequent adverse events, pain, return visits or hospitalizations, or delayed diagnoses of other serious conditions.

Should your medical decision-making change if the patient has a history of nephrolithiasis?

In this study, patients with a history of nephrolithiasis were less likely to undergo additional imaging with CT if they already had an ultrasound first. They did not have poorer outcomes than patients without a history of nephrolithiasis. This suggests that it is safe to avoid ordering a CT in patients with recurrent stones.

What would you do if the same patient presented again with persistent pain from a previously diagnosed stone?

The majority of patients with adverse outcomes were due to infectious causes. Consider alternative diagnoses such as pyelonephritis. Additionally, although rare, renal infarct can present with acute flank pain and is diagnosed with a contrast CT.

References

Fwu, C. W., Eggers, P. W., Kimmel, P. L., Kusek, J. W., & Kirkali, Z. (2013). Emergency department visits, use of imaging, and drugs for urolithiasis have increased in the United States. Kidney international, 83(3), 479-486.
Coursey, C. A., Casalino, D. D., Remer, E. M., Arellano, R. S., Bishoff, J. T., Dighe, M., ... & Leyendecker, J. R. (2012). ACR Appropriateness Criteria® acute onset flank pain–suspicion of stone disease. Ultrasound quarterly, 28(3), 227-233.
Smith-Bindman, R., Aubin, C., Bailitz, J., Bengiamin, R. N., Camargo Jr, C. A., Corbo, J., ... & Kang, T. L. (2014). Ultrasonography versus computed tomography for suspected nephrolithiasis. New England Journal of Medicine, 371(12), 1100-1110.

Expert Commentary

Thank you very much to Dr.’s Ughreja and Akhetuamhen for an excellent blog post on a very relevant clinical topic. This is a great summary of the landmark randomized trial published in NEJM in 2014 assessing CT vs two types of US for patients with suspected renal colic in the ED setting. It is worth mentioning that this study was a multicenter study based in the US with representation from ED, Radiology, and Urology. The above study was well summarized and bears repeating that, in this multicenter randomized study assessing CT vs POCUS vs radiology performed US in patients with suspected renal colic in the ED setting, initial US reduced radiation exposure without adversely affecting patient-centered outcomes. It is worth mentioning several additional considerations and placing emphasis on others elucidated from this journal club review.

First, a subsequent systematic review (1) incorporating multispecialty (ED, Radiology, Urology) expert panel consensus recommendations has reiterated that in younger patients without a high suspicion for alternative diagnoses or complicating features of nephroureterolithiasis (such as fever, pyelonephritis, solitary kidney, dialysis, etc), US should be the initial diagnostic imaging modality of choice, if any. It's a great paper, worth reading (and appreciating who the authors are), and worth recalling for bedside teaching to junior learners in the ED.

Additionally, this paper brings to mind my second point, and something that is worth shouting from the hilltops -- a kidney stone is a clinical diagnosis! Now, of course, this is exclusive of those patients with high-risk or complicating features (e.g. pediatrics, pregnancy, solitary kidney, fever, unstable/critically ill, unrelenting pain, atypical features, etc). You don’t need any imaging to tell you the diagnosis in the vast majority of patients. US or CT are helpful in confirming the diagnosis when there is uncertainty or non-trivial pretest probability of alternative diagnoses, excluding alternative diagnoses, and identifying exact stone location and size, which can be used to help counsel patients at the bedside regarding the anticipated clinical course and next steps in management.

Third, for those with proper training, and with some exceptions (see the systematic review paper for case vignettes that highlight these), POCUS is non-inferior to radiology-performed US. And, it's not a “formal” US. I can’t remember the last time I attended a black-tie ultrasonography session, but that's just me.

Fourth, it's worth mentioning that although CT use can lead to the identification of incidental findings more commonly than US, identification of these incidental findings still happens rather often with POCUS (a common example is a renal cyst). Please ensure that you document and discuss with the patient accordingly.

Finally, a burden on us as EM clinicians is training in and awareness of clinical practice guidelines and recommendations from specialties outside of EM. As it relates to the diagnostic evaluation of suspected renal colic in the ED setting, the Choosing Wisely recommendations endorsed by the AUA are worth perusing as are the European/EUA guidelines, both of which suggest US as the initial diagnostic imaging modality of choice, for pediatric (CW) and non-high-risk patients without complicating features (EUA).

The bottom line is that CT is helpful for older patients or those in whom you are less sure about the diagnosis of renal colic. For younger or low-risk patients, suspected renal colic is a clinical diagnosis and often needs no imaging, but ultrasound would be an evidence-based first step. Thanks again toDr.’s Ughreja and Akhetuamhen.

References

1) Moore et al. Imaging in suspected renal colic: a systematic review of the literature and multispecialty consensus. J Urol 2019. 202(3):475-483.

Tim Loftus, MD, MBA

Assistant Professor of Emergency Medicine

Fellowship Director of the Clinical Operations and Administration Fellowship Program, Northwestern Department of Emergency Medicine

Medical Director of Emergency Services Northwestern Lake Forest Hospital and Grayslake Emergency Center

How To Cite This Post:

[Peer-Reviewed, Web Publication] Ughreja, K. Akhentuamhen, A. (2022, May 16). Journal Club: Ultrasonography versus Computed Tomography for Suspected Nephrolithiasis. [NUEM Blog. Expert Commentary by Loftus, T]. Retrieved from http://www.nuemblog.com/blog/nephrolithiasis-ultrasonography-versus-computed-tomography.

Hip Pain in Pediatrics

Written by: Tommy Ng, MD (NUEM ‘24) Edited by: Patricia Bigach, MD (NUEM ‘22) Expert review by: Terese Whipple, MD '20

So your kid won’t walk

One of the most common complaints in a pediatric Emergency Department is a child refusing or inability to ambulate. For normal development, a child is typically able to stand at 9 months, walk at 12 months, and run at 18 months. There is a certain degree of variability for these age constraints however any acute decrease in mobility should prompt an evaluation. A limp is defined as any abnormality in gait caused by pain, weakness, or deformity [1]. There are a plethora of conditions that can manifest with an antalgic gait or refusal to bear weight and it may be difficult to distinguish between etiologies given a child’s age.

History and physical

Age is an important factor as certain conditions are more likely depending on the patient’s age

Acuity should be determined as the chronicity of limp as certain etiologies are more acute while others are indolent. Additionally, certain infectious etiologies are more likely to present acutely or chronically.

Fever may suggest an infectious or rheumatologic cause

Trauma can help distinguish soft tissue vs orthopedic injuries

Past medical history is important to be focused on recent illnesses, antibiotic use, history of sickle cell disease, or hormonal diseases.

Physical examination should always include an attempt to ambulate the child unless there is an obvious contraindication noted immediately (eg open fracture). If the child refuses to bear weight, the child should be made non-weight bearing until serious pathology which can be worsened by walking is ruled out. Strength and range of motion of both lower extremities should also be examined [2].

Differential: the bad, the worse, and the ugly

Infectious

Transient Synovitis - Relatively common with a lifetime risk of 3%. Affects ages 3-8, males to females 2:1 [3]. Typically well appearing with normal labs, however, this is a diagnosis of exclusion and a septic joint should be ruled out. Management includes NSAID use and return to activity as tolerated [4].
Septic Arthritis - A “do not miss” diagnosis, commonly ages 3-6 with a slight male predominance [5]. Typically presenting with fevers and abnormal labs. The Kocher Criteria (originally developed in 1999 and validated in 2004) can be helpful in determining the likelihood of septic arthritis [6]. Management includes imaging studies, typical ultrasound to assess for a joint effusion, then a diagnostic arthrocentesis & antibiotics. The antibiotic regimen should be tailored to the child’s age and other predisposing factors to certain pathogens.

Osteomyelitis - Occurs in 1:5000-7700 kids in increased prevalence with MRSA communities; 2:1 male to female predominance with half of all cases occurring in ages less than 5 [7]. Commonly hematogenous spread from bacteremia; clinical suspicion should prompt radiologic evaluation. X-rays may be likely to be normal/inconclusive early in the disease course and MRI may be often indicated. Labs can be helpful but are not specific; a systematic review of >12,000 patients showed that elevated WBC was only present in 36% of patients [7]. ESR and CRP are non-specific but have a sensitivity of 95% [7]. Antibiotic therapy guidelines are similar to the management of septic arthritis. Surgical intervention may be indicated if there is a lack of improvement after 48-72 hours [8].

Osteomyelitis of the distal tibia (orthobullets.com)

Orthopedic

Legg-Calve-Perthes / Avascular Necrosis of the Hip - Age range 3-12 with a peak at 5-7, male to female ratio 3:1, can be bilateral in 10-20% of patients [9]. Radiographs should be obtained with high clinical suspicion but are often normal early in the course. An MRI would show fragmentation of the femoral head. The patient should be made non-weight bearing and be referred to a specialist. Children under 8 typically have a better prognosis however long-term management is poorly defined as there has been no long-term study [10].

Avascular necrosis of bilateral hip (orthobullets.com)

Slipped Capital Femoral Epiphysis - Typically obese child, median age 12, bilateral in 20-40% of cases [11]. Presentation is classically chronic hip pain with antalgic gait however may present with knee pain. Physical exam classically shows external rotation and abduction of the hip during hip flexion. Management is orthopedic consultation for operative stabilization [12].

References

Smith E, Anderson M, Foster H. The child with a limp: a symptom and not a diagnosis. Archives of disease in childhood - Education & practice edition. 2012;97(5):185-193. doi:10.1136/archdischild-2011-301245.
Naranje S, Kelly DM, Sawyer JR. A Systematic Approach to the Evaluation of a Limping Child. Am Fam Physician. 2015 Nov 15;92(10):908-16. PMID: 26554284.
Landin LA, Danielsson LG, Wattsgård C. Transient synovitis of the hip. Its incidence, epidemiology and relation to Perthes' disease. J Bone Joint Surg Br. 1987;69(2):238-242.
Kermond S, Fink M, Graham K, Carlin JB, Barnett P. A randomized clinical trial: should the child with transient synovitis of the hip be treated with nonsteroidal anti-inflammatory drugs?. Ann Emerg Med. 2002;40(3):294-299. doi:10.1067/mem.2002.126171
Bennett OM, Namnyak SS. Acute septic arthritis of the hip joint in infancy and childhood. Clin Orthop Relat Res. 1992;(281):123-132.
Kocher MS, Zurakowski D, Kasser JR. Differentiating between septic arthritis and transient synovitis of the hip in children: an evidence-based clinical prediction algorithm. J Bone Joint Surg Am. 1999;81(12):1662-1670. doi:10.2106/00004623-199912000-00002
Dartnell J, Ramachandran M, Katchburian M. Haematogenous acute and subacute paediatric osteomyelitis: a systematic review of the literature. J Bone Joint Surg Br. 2012;94(5):584-595. doi:10.1302/0301-620X.94B5.28523
Kaplan SL. Osteomyelitis in children. Infect Dis Clin North Am. 2005;19(4):787-vii. doi:10.1016/j.idc.2005.07.006
Johansson T, Lindblad M, Bladh M, Josefsson A, Sydsjö G. Incidence of Perthes' disease in children born between 1973 and 1993. Acta Orthop. 2017;88(1):96-100. doi:10.1080/17453674.2016.1227055
Canavese F, Dimeglio A. Perthes' disease: prognosis in children under six years of age. J Bone Joint Surg Br. 2008 Jul;90(7):940-5. doi: 10.1302/0301-620X.90B7.20691. PMID: 18591607.
Herngren B, Stenmarker M, Vavruch L, Hagglund G. Slipped capital femoral epiphysis: a population-based study. BMC Musculoskelet Disord. 2017;18(1):304. Published 2017 Jul 18. doi:10.1186/s12891-017-1665-3
Reynolds RA. Diagnosis and treatment of slipped capital femoral epiphysis. Curr Opin Pediatr. 1999;11(1):80-83. doi:10.1097/00008480-199902000-00016

Expert Commentary

Thank you to Drs. Ng and Bigach for compiling a concise approach to a common chief complaint encountered by Emergency Physicians across the county: a child with a new limp or the refusal to bear weight.

The first step to this often-challenging problem is to try to localize the pain, and in non-verbal kiddos, this can be the most difficult task. As highlighted above, if the child is able, observe their ambulation and establish laterality of the limp and when it occurs during the gait cycle. Most of the disease processes we as Emergency Physicians are concerned about will cause an antalgic gait or a shortened stance phase. Shortening the stance phase decreases the amount of time that the child is bearing weight on the painful limb in an effort to decrease their pain. Sometimes this is so effective that their parents will observe a limp, but the child will not complain of any pain. A thorough exam of the back and lower extremities including inspection, palpation, and range of motion of all joints is also imperative for trying to localize the cause of their symptoms.

Let your exam and history guide lab evaluation and imaging, however, a good place to start is usually basic labs and inflammatory markers and a plain film of the affected joint. In some cases, you won’t be able to localize pain or exam findings at all, and a broad workup including plain film imaging of the entire extremity may be necessary.

A few additional pearls:

Always consider non-accidental trauma in children with new limp or refusal to bear weight.
Systemic symptoms such as fever should raise your suspicion for infectious etiology such as osteomyelitis or septic arthritis.
Classically children with transient synovitis will have had a recent viral illness, but this is not always the case.
Always examine the hips and consider hip plain films in children complaining of knee or thigh pain, but with a benign knee exam. They could be hiding an SCFE or Leg-Calve-Perthes disease.
Don’t forget to examine the SI joint, as it too can become infected or inflamed.
History of night pain should raise your antenna for malignancy like osteosarcoma, Ewing’s sarcoma, or leukemia.
Consider Lyme arthritis in your differential for joint pain and swelling in endemic areas.
Ultrasound can be useful when evaluating for septic arthritis and transient synovitis and can be performed at the bedside. However, both septic arthritis and transient synovitis can cause effusion, and therefore it is not useful in differentiating between the two. (That’s where the Kocher Criteria should be used to risk-stratify and determine if joint aspiration and fluid analysis are warranted)

Ultrasound evaluation of a pediatric hip joint demonstrating effusion courtesy of Dr. Maulik S Patel (https://radiopaedia.org)

Finally, make sure that the parents understand the diagnosis, expected course, and follow-up plan. If the child continues to refuse to bear weight, their symptoms worsen or do not improve, or they develop new concerning symptoms such as new fever or new urinary retention, they should return to the Emergency Department or their pediatrician for re-evaluation. More than once I’ve had patients who seemed for all the world to have transient synovitis eventually be diagnosed with spinal cord tumor, chronic recurrent multifocal osteomyelitis, etc.

Terese Whipple, MD

Assistant Professor

Department of Emergency Medicine

University of Iowa Hospitals and Clinics

How To Cite This Post:

[Peer-Reviewed, Web Publication] Ng, T. Bigach, P. (2021, Dec 20). Hip Pain in Pediatrics. [NUEM Blog. Expert Commentary by Whipple, T]. Retrieved from http://www.nuemblog.com/blog/hippainpediatrics

Sono Pro Tips and Tricks for Acute Appendicitis

**Written by:** Morgan McCarthy, MD (NUEM ‘24) **Edited by:** David Feiger, MD (NUEM ‘22)
**Expert Commentary by**: Shawn Luo, MD & John Bailitz, MD

Welcome to the NUEM SonoPro Tips and Tricks Series where Local and National Sono Experts team up to take you scanning from good to great for a particular diagnosis or procedure.

Did you know, appendicitis is one of the most common surgical emergencies. Despite this, some data suggests that appendicitis is missed in 3.8% to 15% of children and 5.9% to 23.5% of adults in ED visits. Appendicitis is difficult to diagnose due to the early nonspecific generalized symptoms (anorexia, generalized pain, nausea, diarrhea or constipation). We can use point of care ultrasound (POCUS) to help evaluate your differential diagnosis. One study showed that after only a 20-minute training ED physicians at various levels of experience were able to scan for appendicitis with a specificity of 97.9% and a sensitivity to 42.8%.

Beyond the classic pediatric patient, who else does the SonoPro scan?

Pocus use for appendicitis is one of the leading diagnostic tools in pediatrics for acute appendicitis. In the pediatric population limiting radiation is generally thought to be of utmost importance. The lack of exposure to radiation and small habitus makes ultrasound a great alternative in the pediatric patient. These tips and tricks can be useful in other high risk adult patients, like pregnant women. It is well known that in adults there is often a higher chance of pathology and surgeons are managing the ultimate say on whether more imaging is necessary. However, the use of ultrasound for acute appendicitis may save time, expedite care, lead to quicker consultation, and potentially augment patient satisfaction and improve outcomes.