Month: February 2025

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Case 43: Shortness of Breath

Molly Chou

An 83-year-old male presented to our emergency department with shortness of breath. He woke up that morning with symptoms and called EMS. On arrival, the patient was alert and oriented with SpO2 90% on room air. The patient had a recent admission for right middle and lower lobe pneumonia. He also reported a history of heart failure with mildly reduced ejection fraction, coronary artery disease, and chronic kidney disease.

Vitals: BP 122/71, HR 92, RR 30, T 98.8F, spO2 90% on room air, 99% on 4LNC

Exam: Normal heart sounds, tachypnea, rhonchi in bilateral lower lobes, non-tender abdomen, >4mm pitting lower extremity edema

Labs: Cr 2.23 (from 1.98), BNPP 34,591 (from 19,366), WBC 31

EKG: new left bundle branch block

CXR: pulmonary edema, bilateral pleural effusions, and opacities that may represent atelectasis, though cannot rule out pneumonia or aspiration.

A bedside ultrasound was performed:

Figure 1: Right-sided pleural effusion, atelectasis, and pneumonia in seen right lower lobe

Figure 2A: During exhalation. Left-sided pleural effusion, atelectasis. 2B: During inhalation. Pneumonia becomes more visible as air fills alveoli adjacent to consolidated lung tissue (also known as “dynamic air bronchogram”)

Discussion: Bedside ultrasound demonstrated persistent pneumonia as a likely contributor to his shortness of breath. While other clinical indicators directed the diagnosis toward acute on chronic heart failure, POCUS was instrumental in also identifying persistent pneumonia. The patient was ultimately started on antibiotics and admitted to Cardiology for pneumonia and diuresis.

Learning points:

  • Pneumonia is among the leading causes of hospitalization, and it can be detected on ultrasound if the pleural line is involved, which is in about 99% of cases.
  • Ultrasound can detect inflammation and lung-tissue thickening of lobar pneumonias and consolidations. Interstitial pneumonias more often manifest as B-lines or white lung areas. Complications such as empyema and lung abscess can also be detected [1].
  • POCUS is highly sensitive (estimated around 93%) and specific (estimated around 98%) for pneumonia, particularly if done by a skilled sonographer [2,3].
  • Classic ultrasound findings:
    • “Hepatization” of lung parenchyma, when multiple hypoechoic areas give the tissue a “liver-like” or “spleen-like” appearance.
    • “Shred sign” (Figure 1), when a clear margin can be detected separating a consolidation with aerated parenchyma.
    • Air bronchograms (hyperechoic, linear punctate spots) can be detected within a consolidation in over 90% of pneumonia patients, though they are non-specific, as they may indicate any form of airway obstruction [1].
      • However, “dynamic air bronchograms” (Figure 2) where air-filled bronchograms move with respiration, are highly specific (94%) to pneumonia and have a high positive predictive value (97%) when seen [4]. An example can be seen below [5]:

References:

  1. Boccatonda A, Cocco G, D'Ardes D, et al. Infectious Pneumonia and Lung Ultrasound: A Review. J Clin Med. 2023;12(4):1402. Published 2023 Feb 10. doi:10.3390/jcm12041402
  2. Reissig A, Copetti R, Mathis G, et al. Lung ultrasound in the diagnosis and follow-up of community-acquired pneumonia: a prospective, multicenter, diagnostic accuracy study. Chest. 2012;142(4):965-972. doi:10.1378/chest.12-0364
  3. Chavez MA, Shams N, Ellington LE, et al. Lung ultrasound for the diagnosis of pneumonia in adults: a systematic review and meta-analysis. Respir Res. 2014;15(1):50. Published 2014 Apr 23. doi:10.1186/1465-9921-15-50
  4. Lichtenstein D, Meziere G, Seitz J. The Dynamic Air Bronchogram: A Lung Ultrasound Sign of Alveolar Consolidation Ruling Out Atelectasis. Chest. 2009;135(6):1421-1425. Published 2009 Jan 8. doi:10.1378/chest.08-2281
  5. Hailey Hobbs, MD. Dynamic Air Bronchograms. NephroPOCUS. Published 2019 Jul 1. Accessed 2024 Dec 13.
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Case 42: Nephrolithiasis

Alex Liang, Rachna Subramony

A 48 year old male with past medical history of Crohn’s Disease, cryptogenic cirrhosis, pancytopenia, portal vein thrombosis, Factor V Leiden, and prior history of kidney stones presenting with right sided flank pain, dysuria, and hematuria worsening over the past 4 days. He reports similar symptoms in the past associated with his previous findings of kidney stones. He denies fever, nausea, vomit, diarrhea, chest pain, shortness of breath, or anuria.

Vitals: BP 123/80 mmHg | Pulse: 101 | Temp: 98.5 °F (36.9 °C) | Resp: 20 | Wt: 65.8 kg (145 lb) | SpO2: 97%

On physical examination, the patient is alert and uncomfortable but not in acute distress. Abdominal examination reveals a soft, non-distended abdomen with right flank and right costovertebral angle (CVA) tenderness. The remainder of the physical exam, including cardiac, pulmonary, and neurologic exams, was unremarkable.

A bedside ultrasound was performed on the right kidney.

Figure 1: Several renal calculi in the medullary pyramids of the right kidney. The largest measures approximately 6.8mm in diameter.

Discussion

Nephrolithiasis, commonly referred to as kidney stones, is a prevalent condition with an estimated annual incidence rate of approximately 0.5% to 1% in the general population and a lifetime risk of 10%-15% with higher prevalence among men. Risk factors for nephrolithiasis include dehydration, dietary factors (high sodium or oxalate intake), obesity, metabolic syndrome, and recurrent urinary tract infections1,2.

The differential diagnosis for nephrolithiasis includes conditions that present with acute flank pain, hematuria, and urinary symptoms. Such conditions include pyelonephritis, renal infarction, or ureteropelvic junction obstruction. In this patient, the presentation of acute right flank pain with costovertebral angle tenderness accompanied by dysuria and gross hematuria is strongly indicative of nephrolithiasis.

On physical examination, patients with nephrolithiasis typically present with costovertebral angle tenderness on the affected side with otherwise minimal abdominal findings. The clinician should be attentive of systemic signs such as fever and tachycardia, as they may suggest a concurrent urinary tract infection or obstructive pyelonephritis and require further work up. In this case, the patient presented without fever or systemic signs of infection, supporting a diagnosis of uncomplicated nephrolithiasis.

While non-contrast computed tomography (CT) of the abdomen and pelvis is the gold standard for diagnosing nephrolithiasis, ultrasound remains an asset in the detection of stones with a sensitivity of 54% and specificity of 71%. In some cases, such as in pregnant patients, ultrasound is the preferred modality due to its lack of ionizing radiation. In this case, a renal ultrasound revealed several stones in the medullary pyramids of the right kidney, with the largest measuring 6.8mm in diameter. It is important to note that CT does have higher sensitivity (88%) and lower specificity (58%) compared to ultrasound. Despite this, no evidence has shown that increased CT use is associated with improved patient outcomes when compared to ultrasonography 3.

When performing a point-of-care ultrasound (POCUS) exam for nephrolithiasis, the curvilinear or phased-array transducer should be placed in the flank region along the midaxillary line to obtain longitudinal and transverse views of the kidney. The exam focuses on the identification of hydronephrosis, which appears as anechoic dilation of the renal collecting system, and the detection of renal calculi, which appear as echogenic foci with posterior acoustic shadowing.

Management of nephrolithiasis depends on the size and location. Stones that are less than or equal to 5mm are typically managed conservatively with hydration and analgesia. Medication such as tamsulosin can be given to aid in the expulsion of the stones. Stones that are 10mm or greater, causing significant obstruction, or with concurrent infection or renal impairment often require more invasive measures such as extracorporeal shock wave lithotripsy (ESWL), ureteroscopy with laser lithotripsy, or percutaneous nephrolithotomy 4.

Recurrence of nephrolithiasis is common, with a rate of approximately 50% within 10 years. Patients can decrease this risk with preventative strategies such as dietary modifications (increased fluid uptake, reduced sodium and oxalate consumption) and addressing underlying metabolic abnormalities 4.

References

  1. Pearle MS, Calhoun EA, Curhan GC. Urologic Diseases in America Project: Urolithiasis. J Urol. 2005;173(3):848–857. doi:10.1097/01.ju.0000152082.14384.d7.
  2. Scales CD, Smith AC, Hanley JM, Saigal CS. Prevalence of Kidney Stones in the United States. Eur Urol. 2012;62(1):160–165. doi:10.1016/j.eururo.2012.03.052.
  3. Smith-Bindman R, Aubin C, Bailitz J, et al. Ultrasonography versus Computed Tomography for Suspected Nephrolithiasis. N Engl J Med. 2014;371(12):1100-1110. doi:10.1056/NEJMoa1404446.
  4. Curhan GC. Epidemiology of Stone Disease. Urol Clin North Am. 2007;34(3):287–293. doi:10.1016/j.ucl.2007.05.003.
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