Pediatric Emergency Medicine (PEM) Pearls
Created in 2015, this series is hosted by Dr. Jessica Chow and Dr. Josh Bukowski who are authors and editors for this series which focuses on evidence-based care in the realm of pediatric emergency medicine.
A 10-year old girl presents with progressively worsening right lower quadrant pain for the last 2 days. She reports having chills and feeling warm. Her review of systems is negative for nausea, vomiting, diarrhea, or urinary symptoms. Her abdominal exam is unremarkable except for some diffuse, mild tenderness with deep palpation in bilateral lower quadrants. Labs: WBC 9 x 10^9/L. Because of radiation exposure concerns, you order an abdominal ultrasound as the initial imaging modality to evaluate for appendicitis. The radiologist’s reading was: “Unable to visualize the appendix.” Now, what do you do?
Appendicitis is one of the most common surgical emergencies and accounts for 5-10% of all abdominal pain among pediatric patients. Diagnosis can be deceptively difficult given that the complaints can be vague and nonspecific among children. Furthermore, this disease can mimic and be mimicked by many other pathologies making the clinical exam challenging. Laboratory tests, as well as clinical decision-making tools can help guide a clinician, but are limited, especially since early in disease progression, there may not be any demonstrated abnormalities.1
The use of some type of imaging modality is now more frequently incorporated to help assess for appendicitis. The sensitivity and specificity for computer tomography (CT) has been quoted as 94 and 95%, respectively, while for ultrasound (US), it is around 88% and 94%, respectively.1 In one particular 2012 study by Trout et al., the sensitivity for US for the diagnosis of acute appendicitis was as low as 66.4%, although the specificity was 95.9%, with a false negative rate of 33.5%.2
While CT/MRI improves diagnostic accuracy, many institutions use US as the initial imaging modality in order to minimize radiation exposure, and need for IV access and sedation.1,3 However, US results can vary for many reasons:2
Often clinicians are left in a quandary when the interpretation for the appendix is “equivocal,” “non-visualized,” “limited,” or “inconclusive.” This occurs 25-73% of the time.4,5 So now what? Many times, we progress to CT/MRI imaging as if the US study was never performed. Some clinicians incorporate other strategies including serial abdominal exams or repeated US studies. These alternative strategies, however, require a much longer ED stay.
New data suggests that an adequately performed US examination has some negative predictive value (NPV) for appendicitis despite the appendix not being seen (“non-visualized”), assuming that there are no other abnormalities present.5,6
A recent Journal of Pediatric Surgery 2015 study reports that an indeterminate abdominal US has some negative predictive power in risk stratifying the patient for appendicitis. From 2004-2013 at a single tertiary academic center, Cohen et al. did a retrospective chart review study of 1,260 patients who underwent abdominal US where appendicitis was suspected. 63% of the initial US findings were deemed non-diagnostic, with 56% of these due to non-visualization of the appendix. The authors then calculated NPV for non-diagnostic and non-visualized US results, as a function US alone, a serum WBC cutoff of 7.5 x 10^9/L, and a serum WBC cutoff of 11.0 x 10^9/L. The results are summarized in the table.6
|US Study Result
|NPV for Appendicitis
|US + Serum WBC* <7.5
|US + Serum WBC* <11
|Non-diagnostic because of non-visualized appendix
|* WBC units are in 109/L
** Cases were categorized as non-diagnostic if they were not clearly or mostly conclusive in being a positive or negative ultrasound study for acute appendicitis
This study, examined the relationship between a non-diagnostic US and a primary outcome measure of appendicitis. With a non-diagnostic US and a serum WBC count of <7.5 x 10^9/L, one might be able to have a shared decision discussion with the family about observing the patient at home or as an inpatient without further immediate imaging. The NPV is 97.1% (or 98.9% if the appendix was not visualized). A limitation of this study is that it is a single-site retrospective study.6
For many clinicians, when we get a “non-visualized appendix” US reading, we still feel pressed to get further imaging, even if our suspicion is low. For those low-risk patients, regardless of the next imaging modality, they will already have a high NPV (86.4% in one study).7
Radiologists will also look for secondary findings suggestive of appendicitis, including the presence of an appendicolith, free fluid or fluid collection, echogenic inflammatory changes or hyperemia. A study by Ross et al. found that those with at least one of these secondary signs had an odds ratio of 6.52 of having appendicitis.4
A major part of the problem is how US findings are reported, because they can wildly vary by institution and by US technician. Providing a standardized and comprehensive report can help minimize confusion and clarify what descriptives mean. Fallon et al, created an “Appy-Score” which helped categorize various findings, though their “equivocal” definition was a catch-all for those that did not fit into the other groups (e.g. periappendiceal inflammatory changes or borderline enlargement with an otherwise normal appendix). They demonstrated that by using their US scoring system, they were able to reduce overall CT use by 38%.8
|Completely visualized normal-appearing appendix with no ancillary findings to suggest appendicitis
|Partially visualized normal-appearing appendix with no findings to suggest appendicitis
|Non-visualized appendix with no ancillary findings to suggest appendicitis
|Non-perforated acute appendicitis
|Adapted from Larson et al5 Table 1
Larson et al. used 5 specific interpretative categories to provide more description about their US findings. In patients with a non-visualized appendix but with positive secondary findings, the appendicitis rate was 39.3%, while those without any secondary findings, had a rate of 3.8%.5
Given a 50/50 chance of having an equivocal US exam, having a pre-test risk probability based on clinical exam and/or scores (e.g. Alvarado score) may help risk stratify your patients when combined with imaging.
|No. of Points
|Migration of pain to the right iliac fossa
|Anorexia or ketones in the urine
|Nausea or vomiting
|Right lower quadrant tenderness
|Fever of 37.3°C or more
|Leukocytosis of > 10,000/µL
|Neutrophilia > 75%
|Total possible points
|Components of the Alvarado Score
In a study by Blitman et al., they found a NPV of 99.6% for those patients who had an inconclusive US test, but a low Alvarado score (<5) and 89.7% for those with a score of 5-8.9
Many institutions have created a staged approach where they will use ultrasound first, followed by a CT or MRI, if they are unable to visualize the appendix. Given new evidence, we now might consider avoiding additional imaging in certain low-risk populations. These low risk patients have ALL of the following:
In the hands of a proficient US operator, a nonvisualized appendix without secondary findings on US no longer means an automatic CT or MRI scan.
Febrile pediatric patients are ubiquitous in emergency departments (ED) around the country. Parents agonize over the presence, height, and persistence of fever, despite the energy we invest in attempting to reassure them and minimize ‘fever phobia’. But when should we, as providers, also be worried? Very often in pediatric patients we are trying to distinguish self-limited viral infections from potentially harmful bacterial ones. In ill-appearing patients, it’s easy. We treat the patient aggressively as if their symptoms were attributable to a bacterial infection. The proper approach is more opaque with the relatively well-appearing febrile child. How do we pick out the bacterial infections in these cases?
During your shifts in the pediatric ED, you may encounter a few patients with adrenal insufficiency or adrenal crisis. Some of the most common causes include those patients with Addison disease, pituitary hypothalamic pathology, and those patients on chronic steroids. When these patients get sick or sustain trauma, it is important to consider giving them a stress dose of hydrocortisone. Patients in adrenal insufficiency or crisis can present with dehydration, weakness, nausea, vomiting, confusion, lethargy, and severe hypotension refractory to vasopressors. 1–3
A 9-year boy was hit in the head during a soccer game and was out for a few seconds. He regained consciousness quickly, but was repetitive for EMS. By the time the patient arrived at the ED, he was back to his normal self. Did this patient sustain a concussion? If so, what discharge instructions, anticipatory guidance, and resources do you have for your patient and his family? Here’s a quick 170-second animated video tutorial to sum up some thing for you.
The Case: A 5 year old girl presents to the ED with approximately 24 hours of suprapubic and RLQ abdominal pain. Vital signs are: Temp 38.2 C, HR 110, RR 19, BP 100/60, Oxygen Sat 100% on room air. She has vomited twice but has not had diarrhea. She had a history of constipation a year ago that has resolved and mother denies any urinary symptoms or history of UTI’s. The patient is quiet but nontoxic appearing. Your abdominal exam notes mild to moderate RLQ tenderness but no rebound and normal bowel sounds. You order a urinalysis, which is negative and a RLQ US which ‘does not visualize the appendix’. Your suspicion for possible appendicitis is still intermediate; however, now the patient states she is “a little hungry”. Should you order a CT of the abdomen and pelvis? Uuugh!(more…)
Children with chest pain commonly present to the emergency department. Both the child and family members may think their symptoms are due to a serious illness. Among adolescents seen for their chest pain, more than 50% thought they were having a heart attack or that they had cancer.1 In reality, only 6% of pediatric chest pain has a cardiac etiology.2 Nonetheless, extensive and costly emergency department (ED) evaluations are common and there is wide practice variation.3
But prior to reassuring your patient, what can you do to reassure yourself that your patient doesn’t need a more extensive workup? What would make you suspicious for cardiac causes of pediatric chest pain?
You are working your evening shift at the pediatrics emergency department, and you walk into a darkened patient room with a distressed mother and her otherwise healthy 10-year old son who is curled in a ball, holding his head and crying. Her mother tells you that the around-the-clock ibuprofen has barely touched his 2-day headache.
After determining that your patient has no neurologic deficits and that this is most likely a primary headache, what can you do to break his symptoms?