UCSD Ultrasound, Author at UCSD Ultrasound

April 28, 2020December 23, 2020

Case # 20: Right Lower Quadrant Pain

A 40 year old male presented with a 4 day history of right lower quadrant pain. He reported that the pain was at its worse when it started but gradually improved. When in the ED he noted only minimal discomfort without the help of analgesics. He denied ever having anorexia, fever, chills, nausea, vomiting, GU complaints. During examination, he had moderate tenderness to palpation in the right lower quadrant without rebound or guarding.

Vitals: T 97.7F BP 130/77 HR 66 RR 16 SP02 100%

An abdominal ultrasound of the RLQ was performed and the following images were seen. What do you see and what is your most likely diagnosis?

Answer and Learning Points

Answer

In both the longitudinal and transverse views, you see a tubular structure in the right lower quadrant that is non- compressible, greater than 6mm (measures 15.6 mm), and lacks peristalsis. You can also appreciate some dependent free fluid around the appendix. These findings are consistent with the diagnosis of acute appendicitis.

CT abdomen/pelvis showed a retrocecal appendix with finding of acute uncomplicated appendicitis. No bowel obstruction or intra-abdominal/pelvic abscesses. Labs showed a slight leukocytosis to 14, otherwise were reassuring. Patient was given a dose of Zosyn in the emergency department and take to the OR for appendectomy by general surgery.

Learning Points

- Appendicitis is the most common abdominal surgical emergency that presents to the ED in western countries [1].
- The sensitivity and specificity of ultrasound for the diagnosis of appendicitis appears to be around 86% and 81%, respectively, based on results from older studies [2].
- Ultrasound can be used to diagnosis acute appendicitis and may be the imaging modality of choice in certain patient populations such as pregnant women and children [3].
- To obtain images you can use either the linear or curvilinear probe. Ask the patient to point where exactly they hurt and place the probe there. If you don’t see it you can use the landmark of the iliac crest (most lateral), psoas muscle (posterior), and iliac artery (most medial). Move superior and inferior along the iliac artery and the appendix should be just anterior to iliac artery. If you still haven’t found it, “lawnmower” along the right lower quadrant. Look for a tubular, blind ended pouch that has no peristalsis. It should be compressible and measure <6mm in AP diameter [4].

References

1. Caterino, S., et al. Acute abdominal pain in emergency surgery. Clinical epidemiologic study study of 450 patients. Ann Ital Chir. 1997; 68: 807-817.
2. Lim H, Bae S, Seo G: Diagnosis of acute appendicitis in pregnant women: value of sonography. AJR Am J Roentgenol 1992;159(3): 539–542.
3. Excerpt From: Mike Mallin & Matthew Dawson. “Introduction to Bedside Ultrasound: Volume 2.” Emergency Ultrasound Solutions, 2013. Apple Books. https://books.apple.com/us/book/introduction-to-bedside-ultrasound-volume-2/id647356692Mallin, M, Dawson, M. Introduction to Bedside Ultrasound: Volume 2. Emergency Ultrasound Solutions, 2013. Apple Books. https://books.apple.com/us/book/introduction-to-bedside-ultrasound-volume-2/id647356692. Accessed April 18^th, 2020.
4. www.5minsono.com

The following authors contributed to this post:

Amir Aminlari, MD; Danika Brodak, MD; Michael Macias, MD

April 28, 2020July 21, 2020

Case # 19: Under Pressure

A 27 year-old female presented to the emergency department with a two week history of headache, posterior eye pain, visual changes. She denied trauma, fever, focal neurological changes, or visual field deficits. She was seen by the optometrist earlier in the day and was sent to the ED for further evaluation. Her neurological examination was normal.

Eye exam: PERRL, EOMI, no injection/discharge, visual acuity 20/15 OS, 20/20 OD, IOP L19, R19

An ocular ultrasound is performed and the images below are seen. What do you see and what is your most likely diagnosis? What is your management?

Left eye

Right eye

Answer and Learning Points

Answer

On both images of the right and left eye you see papilledema which is demonstrated as a bulging optic disc protruding into the posterior chamber.

CT Head non-contrast was obtained which showed " a partially empty pituitary sella which can be seen with intracranial hypertension, otherwise no acute findings." Ophthalmology was consulted. Their exam was unremarkable except for bilateral papilledema. An LP was performed which showed an elevated OP at 36. After large volume CSF removal the patient reported improvement in symptoms. Closing pressure was 22. The CSF studies were unremarkable. Patient was discharged with an MRI/MRV performed as outpatient and neuro-ophthalmology follow up. MRI brain showed mild flattening of the optic nerve heads which is nonspecific but could correlate with intracranial hypertension in the right clinical setting.

Learning Points

- Papilledema may be directly visualized with ultrasound as a bulging optic disc elevated more than 0.6mm from the retina. There are also studies that show a correlation between increased intracranial pressure and optic sheath nerve diameter greater than 5mm when measured 3mm posterior to the retina. (1-4)
- A width of > 5mm has a pooled sensitivity of 90% and specificity of 85% for detecting an ICP > 20mmHg in trauma patients with head injuries (5-6)
- It is important to note that the optic nerve sheath diameter should be measured when the sides are parallel, as it can be artificially increased otherwise. (7)
- When obtaining an ocular ultrasound use the high frequency linear probe on the ocular setting. If there is not an ocular setting, it is best to err on the high side with regard to gain.
- Although controversial, some sources advise to avoid ocular ultrasound when concerned about globe rupture as any pressure on the eye could worsening the rupture.

References

1. Marchese, R.F., et al. Identification of optic nerve swelling using point-of-care ocular ultrasound in children. Pediatric Emergency Care. 2018; 34(8):531-536.
2. Kimberly, H.H., Shah, S., Marill, K., & Noble, V. Correlation of optic nerve sheath diameter with direct measurement of intracranial pressure. Academic Emergency Medicine. 2008; 15(2):201-4.
3. Amini, A., et al. Use of the sonographic diameter of optic nerve sheath to estimate intracranial pressure. The American Journal of Emergency Medicine. 2013; 31(1):236-9.
4. Xu, W., Gerety, P., Aleman, T., Swanson, J., & Taylor, J. Noninvasive methods of detecting increased intracranial pressure. Child’s Nervous System. 2016; 32(8):1371-86.
5. Dubourg, J., et al. Ultrasonography of optic nerve sheath diameter for detection of raised intracranial pressure: a systematic review and meta-analysis. Intensive Care Medicine. 2011;37(7):1059–1068.
6. Rajajee, V., Vanaman, M., Fletcher, J.J., & Jacobs, T.L. Optic nerve ultrasound for the detection of raised intracranial pressure. Neurocritical Care. 2011;15(3):506–515.
7. Mallin, M, Dawson, M. Introduction to Bedside Ultrasound: Volume 2. Emergency Ultrasound Solutions, 2013. Apple Books. https://books.apple.com/us/book/introduction-to-bedside-ultrasound-volume-2/id647356692. Accessed April 17^th, 2020.

The following authors contributed to this post:

Amir Aminlari, MD; Danika Brodak, MD; Michael Macias, MD; Rachna Subramony, MD

April 24, 2020July 21, 2020

Case # 18: Respiratory Distress: It’s not all COVID.

During the COVID-19 pandemic, a 67 year old woman is brought to the ER by family for respiratory distress and altered mental status. She was alert but not oriented and unable to answer questions on arrival with moderate respiratory distress. Family stated that she had a history of asthma and takes "other" medications, but where otherwise unaware of her past medical history. She had been using her inhaler without relief and has not had any sick contacts, cough or fever.

Vitals: T: 98.7, HR: 112, BP: 190/110, RR: 40, SpO2 80 on RA

She was in moderate respiratory distress, crackles on exam, no pitting edema. She was placed on a non-breather (avoiding NIPPV) and a thoracic plus cardiac ECHO was preformed.

After reviewing the images, what would you do next?

Answer and Learning Points

Answer

The images would suggest that this patient is most likely suffering from heart failure with an acute exacerbation. There are diffuse B-lines, obvious decrease contractility and a dilated IVC. These images are not typical of COVID-19 infections, which have pleural thickening and scattered b-lines (see COVID section). This patient was put on a nitro drip and given diuretics, with a significant improvement in her respiratory status in the ER. She ultimately tested COVID negative and was discharged from the hospital after aggressive diuresis.

During the same shift, numerous COVID-19 positive patients were seen. Below are images of COVID-19 cases for comparison and more can be found at The POCUS Atlas.

While the sensitivity and specificity of ultrasound to diagnosis COVID-19 has yet to be determined, this case illustrates how alternative findings can still impact clinical care and potentially avoid intubation.

COVID +

On the same shift, numerous COVID-19 patients were also seen, with variable pre-test probability. ECHO for these patients would not reveal an alternative diagnosis (such as our CHF case). There were however some classic findings on ultrasound. Note below two patients with thoracic scans. There are scattered B-lines (unlike our CHF patient, who had diffuse B-lines). There is also pleural thickening and at times an irregular pleural border.

Author

Sukhdeep Singh, MD. Clinical Faculty, UCSD Department of Emergency Medicine. Director of POCUS, El Centro Regional Medical Center.

References

DeRose et al, How to Perform Pediatric Lung Ultrasound Examinations in the Time of COVID‐19. Journal of Ultrasound in Medicine. 22 April 2020.
The POCUS Atlas. http://www.thepocusatlas.com/covid19

February 19, 2020July 21, 2020

Case # 17: Par for the Course

An 80 year old man presents to a rural emergency room at 3am with abdominal pain. His past medical history is significant for mild hemophilia A. Six hours prior to arrival, he was driving a golf cart when he struck a pole and the steering wheel hit his stomach.

He initially had no symptoms but began to have abdominal pain while trying to sleep. He also became nauseated and vomited once. He eventually called EMS and was brought to the ER. On arrival, his vitals are as follows.

Vitals: T: 90.7, HR: 108, BP: 74/48, RR: 28, SpO2 98 on 4L

He is alert, oriented and his only complaint is abdominal pain. A FAST exam was done. What do you see? What are your next steps?

Answer and Learning Points

Answer

Although the quality of images is lacking due to the urgency of the situation and the patient's body habitus, the first image (RUQ) does not show obvious free fluid. The following images (suprapubic and LUQ) clearly show free fluid in the abdomen.

An emergent evacuation of the patient to a level 1 Trauma service was requested. Patient was transfused with two units of O blood. Due to his history of hemophilia A, the patient was also given factor VIII to 100% repletion. The patient was taken to the OR at the level 1 trauma center where he was found to have a greater omental bleed and was successfully treated with clot evacuation and laceration repair. He was placed on a factor VIII drip postop.

Learning Points

- Per ATLS guidelines, a hypotensive patient with a + FAST and no other signs of bleeding warrants immediate surgical exploration.
- In a 2018 meta-analysis, a positive FAST has a sensitivity of 68% and a specificity of 95%. Therefore a negative FAST does not rule out the disease, but a positive fast in the correct clinical sitting (such as this) does rule in hemoperitoneum(1).
- Hemophiliac patients require factor VIII replacement to 100% in the setting of major trauma, which is typically 50 IU/kg(2).

Author

Feigenbaum, Adam, PA-C. Emergency Medicine Fellow, Naval Medical Center San Diego.

Sukhdeep Singh, MD. Clinical Faculty, UCSD Department of Emergency Medicine. Director of POCUS, El Centro Regional Medical Center.

References

Stengel D et al. Point-of-care ultrasonography for diagnosing thoracoabdominal injuries in patients with blunt trauma. Cochrane Database Syst Rev. 2018. Dec 12;12
Guidelines for Emergency Department Management of Individuals with Hemophilia and Other Bleeding Disorders. https://www.hemophilia.org/Researchers-Healthcare-Providers/Medical-and-Scientific-Advisory-Council-MASAC/MASAC-Recommendations/Guidelines-for-Emergency-Department-Management-of-Individuals-with-Hemophilia-and-Other-Bleeding-Disorders. December 5, 2019

December 24, 2019July 21, 2020

Case # 16: The Smoking Gun

A 32 year-old woman with history of pleurisy and systemic lupus erythematosus presented to the emergency department with three weeks of shortness of breath and pleuritic chest pain, acutely worse one day prior to arrival.

She flew into San Diego three days prior to her hospital presentation. She became dyspneic when walking from her hotel bed to the bathroom. On review of systems, she did endorse 3 weeks of right lower leg cramping. She denied fever/chills, cough, back pain, or history of blood clots. She was tachypneic and speaking in short phrases upon arrival.

Vitals: T: 98.3, HR: 130, BP: 142/88, RR: 24, SpO2 97% on RA

A bedside ultrasound ECHO and lower extremity scan was preformed. What do you see?

Answer and Learning Points

Answer

These ultrasound images show an apical 4 chamber and parasternal short view of the heart, as well as a right lower extremity DVT. The apical 4 chamber demonstrates right ventricular dilation with bowing of the septum into the left ventricle. The parasternal short illustrates “D sign” with right ventricular dilation and bowing/flattening of the interventricular septum leading to decreased left ventricular systolic function. Both views indicate right heart strain in the setting of likely pulmonary embolism. The right lower extremity showed a noncompressible right femoral vein, indicating DVT.

TPA was prepared and ready to give incase patient had worsening hemodynamic instability. She was fortuantley able to tolerate further imaging without HD compromise; CT angio confirmed the diagnosis of pulmonary embolism in bilateral main pulmonary arteries extending into all 5 lobes. Half dose TPA was administered and the patient was admitted to the ICU.

Learning Points

- Identification of right ventricular dilatation on point-of-care echocardiography for the diagnosis of pulmonary embolism has a sensitivity of 50%, but a specificity of 98%¹
- Patients who present normotensive but have signs of cardiac dysfunction secondary to a PE are classified as submassive, and thrombolytic therapy should be considered²
- When combining echocardiogram with lower extremity ultrasound, the sensitivity and specificity of cardiac US are 91% and 87%, respectively. Venous US shows a lower sensitivity 56%, but higher specificity 95% than cardiac. When cardiac and venous US are both positive the specificity increases to 100%, whereas when at least one was positive the sensitivity increased to 95.³
- There is a broad differential of patients presenting to the emergency department with chest pain and shortness of breath. Point-of-care transthoracic cardiac ultrasound in the ED is an effective tool to promptly diagnose acute pulmonary embolism with right heart strain, and rapidly guide management.^4,5 This patient with a history of lupus and pericarditis could have presented with cardiac tamponade, and ultrasound did show a small circumferential pericardial effusion, but did not show a collapsing right ventricle that would be expected in tamponade (instead, a dilated RV is seen).⁶

Author

Nicolas Kahl, MD. Emergency Medicine Resident. UCSD Department of Emergency Medicine.

Jessica Oswald, MD. Clinical Faculty, UCSD Department of Emergency Medicine.

Sukhdeep Singh, MD. Clinical Faculty, UCSD Department of Emergency Medicine. Director of POCUS, El Centro Regional Medical Center.

References

Dresden S, et al. Right Ventricular dilatation on bedside echocardiography performed by emergency physicians aids in diagnosis of pulmonary embolism. Ann Emerg Med; 2014 Jan; 63(1):16-24
Malik Sonika et al. Advanced Management Options for Massive and Submassive Pulmonary Embolism. USC US Cardiology Review. 2016 Feb.
Nazerian P, et al.Diagnostic accuracy of focused cardiac and venous ultrasound examinations in patients with shock and suspected pulmonary embolism.Intern Emerg Med. 2018 Jun;13(4):567-574
Fields JM, et al. Transthoracic Echocardiography for Diagnosing Pulmonary Embolism: A Systematic Review and Meta-Analysis.J Am Soc Echocardiogr. 2017
Kahl N, et al. Point-of-care Ultrasound Diagnosis of Pulmonary Embolism with Thrombus in Transit.Clin Pract Cases Emerg Med. 2019 Feb; 3(1): 11–12.
Singh, S., et al., Usefulness of right ventricular diastolic collapse in diagnosing cardiac tamponade and comparison to pulsus paradoxus.Am J Cardiol, 1986. 57(8): p. 652-6.

November 5, 2019July 21, 2020

Case # 15: When Lines Go Wild

A 35 year old woman with sickle cell disease presented to the emergency department with localized swelling and pain near her port site. The pain started two days prior to arrival, when she was at an infusion center and her port was found to be inaccessible by the staff. She stated that the staff were unable to draw back any blood. She denied shortness of breath, chest pain, fever, or any other skin changes aside from the swelling.

Vitals: T: 97.8, HR: 64, BP: 144/80, RR: 16, Sat: 96% on RA

A bedside ultrasound ECHO was preformed to evaluate the distal tip of the port. What do you see?

Answer and Learning Points

Answer

These ultrasound images show an apical 4 view of the heart. There is a hyperechoic mass in the right atrium that does not shadow, suggestive of a line thrombosis. A CT angio confirmed the diagnosis, showing a large clot adhered to the distal tip of the catheter.

Learning Points

- Catheter-related complications are common and are the cause of significant morbidity and mortality for patients that have chronic indwelling lines. Symptomatic rates are reported to be 5% with asymptomatic rates increasing to nearly 20%(1).
- Typical imaging beings with an upper extremity ultrasound. However, challenges arise as compression is unattainable when dealing with subclavian vessels(2). CT can improve the sensitivity and specificity(3).
- In our case, a DVT ultrasound would not have been adequate, as the port is inserted over the subclavian vessel. However, a clot located in the heart can be easily detected on a cardiac echo. A CT angio was used to confirm there was a clot adhered to the line, but no pulmonary embolism.
- Ultrasound can be used to evaluate for RV strain and at times may note RA thrombosis (such as in this case), clots in transit, and can be helpful in evaluating lines that extend into the right atrium/right ventricle.

Ultrasound findings of clots on the cardiac echo:

Non-adhered clots will typically be floating/tumbling with cardiac motion. Since they are non-calcified, shadowing does not typically occur.


Dr. Scheels. The POCUS Atlas. http://www.thepocusatlas.com/

This can be difficulty to distingue from other masses, such as an atrial myxoma. However the correct clinical context is able to help.


Dr. Russell. The POCUS Atlas. http://www.thepocusatlas.com/

Using echo to check line placement/wire tips is not uncommon. Obtaining an apical 4 view as done in this case, one can evaluate the right atrium and right ventricle.


Dr. Ftacnikova et al. 3D ECHO 360. http://3decho360.com/cc19/

Author

Sukhdeep Singh, MD. Clinical Faculty, UCSD Department of Emergency Medicine. Director of POCUS, El Centro Regional Medical Center

References

Verso M, Agnelli GJ. Venous thromboembolism associated with long-term use of central venous catheters in cancer patients. J Clin Oncol 2003; 21: 3665–3675.
Sartori M, Migliaccio L, Favaretto E, et al. Whole-Arm Ultrasound to Rule Out Suspected Upper-Extremity Deep Venous Thrombosis in Outpatients. JAMA Intern Med. 2015;175(7):1226–1227. doi:10.1001/jamainternmed.2015.1683
Gita Yashwantrao Karande, Sandeep S. Hedgire, Yadiel Sanchez, Vinit Baliyan, Vishala Mishra, Suvranu Ganguli, Anand M. Prabhakar
Cardiovasc Diagn Ther. 2016 Dec; 6(6): 493–507. doi: 10.21037/cdt.2016.12.06

November 21, 2018July 21, 2020

Case # 14: Whirlpool swirling, twisting and turning

A 13-year-old male presents to the emergency department with right testicular pain for one-hour duration. The pain began while having a bowel movement. He had no nausea or vomiting. His exam is notable for a high riding right testicle and tenderness to palpation over the right testicle.

Vitals: T: 97.8, HR: 106, BP: 135/79, RR: 16, Sat: 96% on RA

A bedside ultrasound of the testicles is performed. What do you see?

Answer and Learning Points

Answer

These ultrasound images demonstrates limited flow into the right testicle suggestive of testicular torsion. Manual detorsion was performed at the bedside using the “open-the-book” maneuver with subsequent ultrasound demonstrating return of flow to the right testicle. Urology was consulted, and the patient was scheduled for an outpatient orchiopexy.

Learning Points

The acute scrotum is a presentation that requires timely evaluation and management by the emergency physician. Of all causes of acute scrotum, testicular torsion is the diagnosis that requires the most emergent action because of the limited time window of testicular salvageability.¹ Unfortunately, in many clinical settings including urgent cares, clinics, and rural community emergency rooms, it can be challenging to confirm our clinical suspicion in a timely fashion because of the difficulty in obtaining an official scrotal ultrasound. For this reason, POCUS is an important tool for emergency physicians in the diagnosis of patients with acute scrotum.

Ultrasound findings of testicular torsion:

Loss or reduction of color Doppler flow/Spectral Doppler tracings to affected testicle (Must compare to other testicle)

Affected testicle becomes more heterogeneous than other testicle

Adhikari, S. R. (2008). Small parts - Testicular ultrasound. Retrieved from https://www.acep.org/sonoguide/smparts_testicular.html

Thickened, hypoechoic mediastinum^⁵

Prando D. Torsion of the spermatic cord: the main gray-scale and doppler sonographic signs. Abdom Imaging. 2009 Sep-Oct;34(5):648-61. doi: 10.1007/s00261-008-9449-8. Review. PubMed PMID: 18709404.

Whirlpool sign⁶

Author

Marissa Wolfe, MS4; Amir Aminlari, MD, Emergency Ultrasound Fellowship Director at UCSD

References

Mellick LB, Sinex JE, Gibson RW, Mears K. A Systematic Review of Testicle Survival Time After a Torsion Event. Pediatr Emerg Care. 2017 Sep 25. doi: 10.1097/PEC.0000000000001287. [Epub ahead of print] PubMed PMID: 28953100.
Sharp VJ, Kieran K, Arlen AM. Testicular torsion: diagnosis, evaluation, and management. Am Fam Physician. 2013 Dec 15;88(12):835-40. Review. PubMed PMID: 24364548.
Wang S, Scoutt L. Testicular torsion and manual detorsion. Ultrasound Q. 2013 Sep;29(3):261-2. doi: 10.1097/RUQ.0b013e3182a2d129. PubMed PMID: 23945494.
Adhikari, S. R. (2008). Small parts - Testicular ultrasound. Retrieved from https://www.acep.org/sonoguide/smparts_testicular.html
Prando D. Torsion of the spermatic cord: the main gray-scale and doppler sonographic signs. Abdom Imaging. 2009 Sep-Oct;34(5):648-61. doi: 10.1007/s00261-008-9449-8. Review. PubMed PMID: 18709404.
Kalfa N, Veyrac C, Lopez M, Lopez C, Maurel A, Kaselas C, Sibai S, Arena F, Vaos G, Bréaud J, Merrot T, Kalfa D, Khochman I, Mironescu A, Minaev S, Avérous M, Galifer RB. Multicenter assessment of ultrasound of the spermatic cord in children with acute scrotum. J Urol. 2007 Jan;177(1):297-301; discussion 301. PubMed PMID: 17162068.
Vijayaraghavan SB. Sonographic differential diagnosis of acute scrotum: real-time whirlpool sign, a key sign of torsion. J Ultrasound Med. 2006 May;25(5):563-74. PubMed PMID: 16632779.

November 9, 2018July 21, 2020

Point-of-Care Ultrasonography for Evaluation of Acute Dyspnea in the ED

Background

Dyspnea is a common presenting symptom in the emergency department, and early diagnosis of underlying disease pathology is crucial in rapid intervention and treatment. Laboratory and radiological tests aid in the diagnosis, but often these results take time.^1-3 Additionally, chest radiographs and chest CTs, the most common radiological tests in the evaluation of dyspnea, have several disadvantages including radiation risks and high costs. Unlike these modalities, point-of-care ultrasound (PoCUS) is cheap with no radiation risk, highly accurate, and has better sensitivity in detecting pneumothorax, pneumonia, and pleural effusions than CXR.^4-7 In addition to being accurate and reliable, PoCUS can be performed rapidly to aid in early diagnosis and treatment of patients.

Point-of-Care Ultrasonography for Evaluation of Acute Dyspnea in the ED

Clinical Question

What is the feasibility and diagnostic accuracy of PoCUS for the management of acute dyspnea in the ED?

Methods & Study Design

Design:

Prospective, blinded, observational study

Population:

This study was conducted at Careggi University Hospital, a university-affiliated teaching hospital.

Inclusion Criteria:

Patients over the age of 18 with acute dyspnea of any degree.

Exclusion Criteria:

Patients with dyspnea of traumatic origin, and those that were discharged from the emergency department after evaluation.

Intervention:

All patients were primarily assessed by 2 separate emergency physicians with vital signs, history, physical exam, and EKG.

One physician performed a Lung, Cardiac, and IVC PoCUS.

One physician performed a standard workup using any combination of Chest X-Ray, Chest CT, Echocardiogram, labs, or Arterial Blood Gas.

Both physicians were asked to make up to 2 diagnoses based on their results.

Possible diagnoses: Heart Failure, Acute Coronary Syndrome, Pneumonia, Pleural Effusion, Pericardial Effusion, COPD/asthma, Pulmonary Embolism, Pneumothorax, ARDS/ALI, Other.

Outcomes

Primary:

Accuracy of diagnosis:

Follow-up chart review determined the reference diagnosis. Results were compared to the diagnosis obtained from the ultrasound group and the standard workup group.

Secondary:

Time to final diagnosis for both groups was recorded.

Time for Ultrasound completion was recorded.

Results

3,487 total patients → 2,683 included in study

Average time to complete US: 7±2 min

Average time to Diagnosis:

Ultrasound: 24 ± 10 minutes

ED: 186 ± 72 minutes

Variable	Sensitivity - Ultrasound	Sensitivity - Standard
Heart Failure	88 (85.1-90.6)	77.3 (73.7 – 80.6)
COPD/asthma	86.6 (84.2-89.2)	92.2 (90.1-94)
Pulmonary Embolism	40 (30.1-50.6)	90.5 (82.8-95.6)

Point-of-care ultrasound had an increased sensitivity in detecting heart failure compared to standard workup.
Point-of-care ultrasound had a decreased sensitivity in diagnosing COPD/asthma and pulmonary embolism compared to standard workup.

There were no differences in the sensitivity or specificity of ultrasound vs. standard workup in all other diagnoses.

Strength & Limitations

Strengths

Adequate sample size obtained for most diagnoses.

Gold standard diagnosis was reviewed by two separate emergency medicine physicians.

Limitations

Ultrasound sonographers focused only on those patients with dyspnea, while the treating physicians were responsible for other patients in the ED.

This likely increased the time to diagnosis for emergency physicians in the standard workup group.

Patients discharged from the hospital were not included in study.

Average age of patient population was 71, but patients 18 and over were accepted.

ARDS patient studies were underpowered.

Authors Conclusion

“Integrated ultrasound methods could replace the current first diagnostic approach to patients presenting with dyspnea, allowing a drastic reduction in costs and diagnostic times.”

Our Conclusion

Point-of-Care Ultrasound in patients with dyspnea provides us with quick information to begin treatment before other laboratory and radiological tests become available. While this study showed that ultrasound was superior to the standard workup in detecting heart failure, it was slightly inferior to the standard workup in detecting COPD/asthma, and significantly inferior to standard workup in detecting pulmonary embolism. The authors speculated that with the inclusion of a DVT ultrasound study would improve the sensitivity for detecting PEs greatly.

There have been other studies demonstrating increased sensitivity using ultrasound in patients to diagnose pneumonia and pleural effusions compared to chest x-ray. This study contributed to our knowledge of the accuracy of ultrasound in undifferentiated dyspnea by demonstrating its accuracy in these other important diagnoses. The study shows that PoCUS can guide and the emergency physician’s workup, help risk-stratify, can help us to begin treatment quickly, and improveflow and efficiency in the ED.

The Bottom Line

Although PoCUS won’t replace a standard workup in many cases, PoCUS can rapidly and accurately aid in determining the underlying diagnosis in patients presenting to the ED with undifferentiated dyspnea and may lead to quicker treatment times and improved flow in the emergency department.

Authors

This post was written by Marissa Wolfe, MS4 at Stony Brook University. Review and further commentary was provided by Amir Aminlari, MD, Ultrasound Faculty at UCSD.

References

Mulrow CD, Lucey CR, Farnett LE. Discriminating causes of dyspnea through clinical examination. J Gen Intern Med. 1993;8(7):383-392.
Schmitt BP, Kushner MS, Wiener SL. The diagnostic usefulness of the history of the patient with dyspnea. J Gen Intern Med. 1986;1(6):386-393.
Nielsen LS, Svanegaard J, Wiggers P, Egeblad H. The yield of a diagnostic hospital dyspnoea clinic for the primary health care section. J Intern Med. 2001;250(5):422-428.
Lichtenstein D, Mezière G. Relevance of lung ultrasound in the diagnosis of acute respiratory failure: the BLUE protocol. Chest. 2008;134(1):117-125.
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.
Zanobetti M, Poggioni C, Pini R. Can chest ultrasonography replace standard chest radiography for evaluation of acute dyspnea in the ED? Chest. 2011;139(5): 1140-1147.
Nazerian P, Volpicelli G, Vanni S, et al. Accuracy of lung ultrasound for the diagnosis of consolidations when compared to chest computed tomography. Am J Emerg Med. 2015;33(5):620-625.

July 25, 2018July 21, 2020

Test Characteristics of Point of Care Ultrasound for the Diagnosis of Retinal Detachment in the Emergency Department

Background

Retinal detachment (RD) is the final diagnosis for 3-4% of patients presenting to the Emergency Department (ED) with ocular complaints. Presenting symptoms most commonly include acute onset flashes and floaters, however, this presentation is not unique. The timely diagnosis and differentiation of RD from more common, benign, and similarly presenting processes, such as posterior vitreous detachment, is important in order to treat RD and prevent the sequela of permanent vision loss.

Point of care ultrasound (POCUS) has been successfully employed in the diagnosis of retinal pathology with high degrees of success according to observed test characteristics (sensitivity 97%-100%; specificity 83-100%) in emergency medicine (EM) literature. The generalizability of this data is limited, however, due to study features, including the use of highly experienced sonographers, inconsistent scanning protocols, and poor reference standards. This investigation seeks to derive the test characteristics for POCUS in the diagnosis of RD when used by a heterogeneous population of emergency physicians (EPs).

Test Characteristics of Point of Care Ultrasound for the Diagnosis of RetinalDetachment in the Emergency Department

Clinical Question

What are the test characteristics (sensitivity and specificity) of POCUS for the diagnosis of RD in patients presenting with chief complaint of flashes or floaters, when performed by a group of emergency physicians with varying degrees of ultrasound experience?

Methods & Study Design

Design
- Prospective study using a convenience sample of patients presenting to the ED with a chief complaint of flashes or floaters in visual fields
Population
- Conducted at Vancouver General Hospital, an urban academic tertiary care center
Inclusion Criteria
- Patients presenting with chief complaint of acute (7 days or less) onset flashes or floaters in one or both eyes between March 2015 and September 2016
Exclusion Criteria
- Age younger than 19 years, known diagnosis of RD, exam compromised due to advanced cataract in the affected eye, ophthalmologic surgery on affected eye within prior two weeks
Intervention
- EP performed ocular POCUS with high-frequency linear transducer
- Scan performed in both transverse and longitudinal plane with dynamic assessment of posterior chamber (patient looking left/right and up/down)
- Positive or negative interpretation for RD was recorded
- Reference Standard
  - Patients were referred to an ophthalmology resident who performed non-blinded assessment including a complete dilated retinal exam
  - Patients were then seen by a retina specialist blinded to the ED POCUS within 1 week, or for patients with a retinal tear or RD diagnosis, within 1 day
- Standardized training session for emergency providers
  - EM attendings (20), fellows (2), and residents (8) of varying ultrasound experience received a 1 hour lecture on the use of POCUS to detect RD
  - All participating EPs performed one practice scan on a healthy volunteers
Outcomes
- Primary outcome: Accuracy of the EP diagnosis with respect to the reference standard, the retina specialist diagnosis
- Test characteristics: sensitivity, specificity, diagnostic accuracy, LR+, and LR-

Results

Flow of Patients Through Study

Primary analysis

- Sensitivity: 75% (95% CI 48-93%)
- Specificity: 94% (95% CI 87-98%)
- Diagnostic accuracy: 91% (95% CI 85-96%)
- LR-positive: 12.4 (95% CI 5.4-28.3)
- LR-negative: 0.27 (95% CI 0.11-0.62)

Secondary analyses

- Test characteristics by level of training
  - Residents and fellows: 100% sensitivity, 95% specificity
  - Attending physicians: 71% sensitivity, 94% specificity
- Test characteristics by number of patients enrolled by EP
  - 1-2 patients enrolled: 80% sensitivity, 71% specificity
  - 3 or more patients enrolled: 73% sensitivity, 98% specificity

Limitations

- Insufficiently powered for the secondary analyses
- Single program study limits generalizability
- Prior ultrasound experience was not explicitly assessed
- RD is not always classically presenting, starting with a population defined by classic symptoms may influence observed test characteristics

Authors Conclusion

“In a heterogeneous group of EPs with varying ultrasound experience, POCUS demonstrates high specificity but only intermediate sensitivity for the detection of RD. A negative POCUS scan in the ED performed by a heterogeneous group of providers after a one-hour POCUS didactic is not sufficiently sensitive to rule out RD in a patient with new onset flashes or floaters.”

Our Conclusion

This study demonstrates that emergency physicians of varying training levels and ultrasound experience can successfully employ POCUS in the diagnosis of RD after only a short training session. By incorporating POCUS into the workup of patients presenting with ocular complaints characteristic of RD, true pathology can be identified with high specificity. Appropriate care can then be mobilized expeditiously in these scan-positive patients in order to prevent the permanent vision loss associated with this condition.

Indeed, a 74% sensitivity is too low for POCUS to reliably be utilized by a heterogeneous population of EPs as a tool to rule-out RD, especially given the consequences of a missed diagnosis. It would be reasonable practice, therefore, as the authors suggest, for all patients with new onset flashes and/or floaters to continue be referred for further ophthalmologic evaluation to definitively rule-out RD and other conditions at-risk for progression to RD. It should also be noted, however, that a trend towards increased specificity was observed amongst physicians who enrolled more patients in this study. Taken in context with test characteristics reported in prior literature, these findings may suggest that specificity can be improved upon with experience, and in the hands of a trained sonographer, POCUS may also be used as a tool to reliably rule-out RD.

The Bottom Line

Emergency providers can reliably use point-of-care ultrasound to diagnose retinal detachment with high specificity after a short, one-time training course, but must recognize the limitations of POCUS as a tool to rule-out RD in this setting, given a relatively low sensitivity when used for this purpose.

Authors

This post was written by Oretunlewa Soyinka, MS4 at UCSD. Review and further commentary was provided by Cameron Smyres, MD, Ultrasound Fellow at UCSD.

References

1 . Hikichi T, Hirokawa H, Kado M, et al. Comparison of the prevalence of posterior vitreous
detachment in whites and Japanese. Ophthalmic Surg 1995; 26:39-43.

2. Hollands H, Johnson D, Brox AC, et al. Acute-onset floaters and flashes: is this patient at
risk for retinal detachment? JAMA 2009; 302:2243-9

3. Alotaibi AG, Osman EA, Allam KH, et al. One month outcome of ocular related
emergencies in a tertiary hospital in Central Saudi Arabia. Saudi Med J 2011; 32:1256-60.

4. Mitry D, Charteris DG, Fleck BW, et al. The epidemiology of rhegmatogenous retinal
detachment: geographical variation and clinical associations. Br J Ophthalmol 2010;
94:678-84.

April 20, 2018July 21, 2020

The Predictive Value of Bedside Ultrasound to Restore Spontaneous Circulation in Patients with PEA: A Systematic Review and Meta-Analysis

Background

Cardiac arrest remains one of the leading causes of death in the United States and is frequently encountered in the emergency department (ED). It is defined as cessation of cardiac function and lack of circulation. Cardiopulmonary resuscitation (CPR) improves outcomes especially if it is performed within minutes of cardiac arrest. According to recent American Heart Association (AHA) statistics, approximately, 10.6% of patients who experience cardiac arrest survive to hospital discharge [1]. On the other hand, pulseless electrical activity (PEA) is a form of cardiac arrest in which patients continue to have organized cardiac electrical activity without a palpable pulse. This patient population's overall survival is much lower with 2.4% of patients surviving to hospital discharge [2]. Until recently, there has been an incomplete understanding of the the term PEA and what this means physiologically. With the advent of ultrasound (US), there has now been elucidation of two forms of PEA. True-PEA (tPEA) which lacks cardiac activity on US, has poor survival rates, while pseudo-PEA (pPEA) which demonstrates some cardiac activity on US, shows improved survival, potentially due to altering standard ACLS protocol driven management. The following study specifically looks at the data evaluating the predictive value of US in patients presenting in cardiac arrest with PEA.

The predictive value of bedside ultrasound to restore spontaneous circulation in patients with pulseless electrical activity: A systematic review and meta-analysis.

Clinical Question

Does bedside US predict the restoration of spontaneous circulation in patients with pulseless electrical activity?

Methods & Study Design

Design
- Systematic review and meta-analysis
- Data from MEDLINE, EMBASE, Cochrane library databases (inception to June 2017)
- Statistical analysis
  - Review Manager 5.4 and Stata 12
  - I2 statistics to assess heterogeneity
  - Random effects model for all polled outcome measures
  - Begg’s test for publication bias
Study Eligibility Criteria
- Adults with PEA
- Cardiac US was used to detect cardiac activity
- ROSC defined as primary outcome
- Prospective/ observational studies
- Written in English
- 2x2 contingency table can be formed from data

Results

Included Studies

- 11 studies with 777 patients with PEA included
- 230 patients had ROSC
- 42/343 "true-PEA" patients had ROSC
- 188/434 "pseudo-PEA" patients had ROSC
- Patients with pPEA were 4.35x more likely to experience ROSC than those tPEA (Risk ratio 4.35, confidence interval 2.20-8.63, p<0.00001, significant statistical heterogeneity I2= 60%)

Limitations

- Significant heterogeneity amongst the 11 studies
  - 4 studies enrolled both trauma and non-trauma patients
  - In 3 studies, US evaluation occurred in the pre-hospital setting
- Large confidence interval
- Small pooled sample size
- Varying protocols and US views used in different studies to determine cardiac activity
- Varying definition of ROSC between studies

Authors Conclusion

"In cardiac arrest patients who present with PEA, bedside US has an important value in predicting ROSC. The presence of cardiac activity in PEA patients may encourage more aggressive resuscitation. Alternatively, the absence of cardiac activity under US could be promoted as a way of confirming a poor prognosis and used to support the decision to terminate resuscitative efforts."

Our Conclusion

This study found that patients in cardiac arrest with pPEA (i.e. cardiac motion on ultrasound) have higher ROSC than those with tPEA (i.e. no cardiac motion on ultrasound). The exact risk ratio for ROSC quoted in their results should be interpreted with caution since this meta-analysis included studies with vastly different characteristics. The 11 studies included took place in 9 different countries over the span of 15 years, included different US views (subxiphoid, parasternal), varied settings (pre-hospital and in-hospital US studies), varied patient populations (some studies included traumatic cardiac arrest) and had varying US operator experience. Additionally, other factors such as time to initiation of CPR, length of CPR, and the previous health of the patient were not accounted for. These limitations can affect the accuracy of the risk ratio presented in this study. That being said, even with significant heterogeneity in this study, resulting in a very wide confidence interval, the lower limit of the risk ratio (2.20) still finds statistical significance for higher rate of ROSC in patients with pPEA compared to patients with tPEA.

This study essentially confirms what is already known from previous data (specifically the Gaspari study which represents the majority of patients in this meta-analysis) but fails to address the big question of "Does US guided resuscitation provide a mortality benefit in the management of cardiac arrest?" This is a complex question that takes into account multiple other questions including the debate over US increasing interruptions in chest compressions, the use of US to identify immediately reversible causes of cardiac arrest (i.e. tamponade, massive PE) , the true definition of cardiac standstill (which calls the results of all cardiac arrest studies thus far into questions), and ultimately, can US be used to determine if further resuscitation is futile? As with all advances in technology, finding the right niche to benefit the patient is of upmost importance and at this point in time, the utility of US in cardiac arrest remains to be determined.

The Bottom Line

Bedside ultrasound can be used to determine pPEA from tPEA in patients with cardiac arrest. This may help guide resuscitation efforts as patients with pPEA have increased rates of ROSC.

Authors

This post was written by Tina Vajdi, MS4 at UCSD. Review and further commentary was provided by Michael Macias, MD, Ultrasound Fellow at UCSD.

References

1. Mozaffarian D, Benjamin EJ, Go AS, Arnett DK, Blaha MJ, Cushman M et al. Heart Disease and Stroke Statistics-2016 Update: A Report From the American Heart Association. Circulation 2016; 133(4):e38– e360. https://doi.org/10.1161/CIR.0000000000000350 PMID: 26673558
2. Engdahl J, Bang A, Lindqvist J, Herlitz J. Factors affecting short- and long-term prognosis among 1069 patients with out-of-hospital cardiac arrest and pulseless electrical activity. Resuscitation 2001; 51 (1):17–25. PMID: 11719169
3. Gaspari R, e. (2018). Emergency department point-of-care ultrasound in out-of-hospital and in-ED cardiac arrest. - PubMed - NCBI . Ncbi.nlm.nih.gov. Retrieved 20 April 2018, from https://www.ncbi.nlm.nih.gov/pubmed/27693280