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Two Patients With Hypotension and Respiratory Distress FREE TO VIEW

Michael H. Bourne, Jr., MD; Hiroshi Sekiguchi, MD
Author and Funding Information

FUNDING/SUPPORT: The authors have reported to CHEST that no funding was received for this study.

CORRESPONDENCE TO: Hiroshi Sekiguchi, MD, Division of Pulmonary and Critical Care Medicine, Mayo Clinic, 200 First St SW, Rochester, MN 55905


Copyright 2016, American College of Chest Physicians. All Rights Reserved.


Chest. 2016;149(2):e41-e43. doi:10.1016/j.chest.2015.12.009
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Published online

A man in his 80s with a history of COPD was admitted to the hospital with pneumonia. A CT scan of his chest revealed a left lower lobe infiltrate with no evidence of pulmonary embolus. Despite fluid administration and antibiotic therapy, he developed hypotension and atrial fibrillation with a rapid ventricular rate. A rapid response team was activated, and the patient was emergently transferred to the ICU while receiving a rapid fluid bolus via a peripheral line. Vital signs on ICU transfer revealed a BP of 111/62 mm Hg, a heart rate of 107 beats/min, and a respiratory rate of 26 breaths/min; pulse oximeter oxygen saturation was 91% on 4 L of oxygen. On physical examination, bilateral rales were heard on lung auscultation.

A bedside cardiac critical care ultrasonography (CCUS) was obtained shortly after arrival in the ICU and was repeated 30 min later (Video 1). After ICU admission, antibiotics were broadened for health-care-associated pneumonia, and prednisone was started for concomitant COPD exacerbation.

A woman in her 70s with a history of dementia, congestive heart failure, and COPD was admitted to the hospital after a mechanical fall. A CT scan of the pelvis revealed a right superior and inferior pubic rami fracture. Orthopedics recommended pain control and nonoperative intervention. Subsequently, the patient developed acute kidney injury requiring dialysis. During her first dialysis session, she developed hypotension, hypoxemia, and an altered mental status. A rapid response team was activated, and the patient was transferred to the ICU. Upon ICU transfer, her vital signs revealed a BP of 105/77 mm Hg, a heart rate of 100 beats/min, and a respiratory rate of 26 breaths/min; pulse oximeter oxygen saturation was 94% on 4 L of oxygen. Her physical examination revealed pale, cool skin and coarse crackles on lung auscultation. Her vital signs initially improved with fluid resuscitation; however, 4 hours after the transfer, she became increasingly confused and hypotensive, and vasopressor agents were started.

A cardiac CCUS is shown in Video 2.

Question (Patient 1): Based on these images, the history, and temporal differences in the CCUS findings, what is the most likely explanation for the particulate matter in the inferior vena cava (IVC) and the cardiac chambers?

Question (Patient 2): Based on these images and history, what is the most likely explanation for the particulate matter in the IVC and the cardiac chambers?

Answer (Patient 1): Subclinical venous air embolism.

Initial cardiac CCUS revealed particulate matter in the IVC and the right chambers. This particulate matter likely represented subclinical venous air originating from the rapid infusion of the fluid bolus.

Answer (Patient 2): Fat embolism.

The cardiac CCUS demonstrated severe right atrial and ventricular enlargement. The particulate matter likely represented fat emboli rather than air emboli, given the patient’s clinical course.

Video 3 is a presentation of the Discussion topics. Ultrasonographic particulate matter is a phenomenon in which small but discrete high acoustic densities move in the vessels and the cardiac chambers. Particulate matter differs in appearance from the swirling “smoke-like” spontaneous echo contrast that can be observed in the right atrial appendage. Although spontaneous echo contrast represents low-flow red cell aggregates and is associated with atrial fibrillation and hypercoagulable states, particulate matter can represent air, fat, bone, cholesterol, and other embolic phenomenon.

In the first patient, air was believed to be the cause of the particulate matter. A previous report described several cases of professional athletes having symptoms consistent with venous air embolism (VAE) from rapid infusion of saline before athletic events. While cases of asymptomatic VAE, such as in the first patient, are believed to occur frequently, VAE can cause significant morbidity and mortality. High infusion pressure increases the likelihood of air displacement into the fluid (1-L bags of IV fluid have anywhere from 50-70 mL of air inside them), which was likely responsible for the air seen on the cardiac CCUS. Estimates of the lethal volume of air in the venous system range from 200 to 300 mL in humans. Trans-esophageal echocardiography (TEE) is the most sensitive method to demonstrate intravascular air and can visualize subclinical levels of air, as little as 0.02 mL/kg. Curiously, the first patient also had particulate matter found in his IVC. The patient’s peripheral IV line was in his upper extremity, and the IVC particulate matter was likely from regurgitant air from the right chambers.

The cause of particulate matter in the second patient was likely fat emboli. Particulate matter secondary to fat emboli has been studied in orthopedic patients undergoing total knee arthroplasty with perioperative TEE. Fat embolism syndrome is a potentially serious consequence of major fractures of the pelvic and long bones, as was the likely cause in our second case. As many as 30% of patients with multiple long bone and/or pelvic fractures will have fat embolism syndrome. Ultrasonographic findings of particulate matter in the IVC and right cardiac chambers, very similar to the second patient, have been observed during total knee arthroplasty and other orthopedic procedures.,,

If particulate matter is observed in nonsurgical patients, air entry via IV access or transvenous device must be ruled out first. In trauma patients, pulmonary contusion should be suspected. Once air embolus is excluded, the possibility of undiagnosed DVT or bone fractures should be considered. Comprehensive venous ultrasonography is helpful for assessing the presence of DVT or other pathologies. Further imaging studies, such as radiography, CT scan, and MRI, may be necessary to exclude undiagnosed fracture. An animal study using TEE found that air emboli tend to have higher intensity signal and accumulate into large masses in the cardiac chambers than fat emboli. Another study using Doppler ultrasonography showed that intensity volume and frequency shift were helpful for discriminating thrombi, fat, or marrow emboli. Although these ultrasonographic parameters may be useful in discriminating the source of particulate matter, they have not been widely integrated into clinical practice.

In summary, ultrasonographic particulate matter is a phenomenon in which small but discrete high acoustic densities, such as air, fat, or marrow emboli, move in the cardiovascular system. Clinical correlation is important, and identification of the correct etiology facilitates early diagnosis and patient management.

  • 1.

    Particulate matter in the IVC and right heart chambers represent embolic phenomenon such as air, fat, and marrow emboli.

  • 2.

    The presence of particulate matter when combined with the history, physical examination, and other ultrasonographic findings can help narrow the diagnosis.

Author contributions: H. S. and M. H. B. had full access to all of the data in the study and take responsibility for the content. H. S. contributed to ultrasound and data collection as well as the conception of the paper. M. H. B. contributed to the primary drafting of the manuscript and the creation and editing of the videos. M. H. B. and H. S. contributed to the paper design, chart review, and revision of the manuscript.

Financial/nonfinancial disclosures: None declared.

Other contributions:CHEST worked with the authors to ensure that the Journal policies on patient consent to report information were met.

Additional information: To analyze this case with the videos, see the online version of this article.

Kerut E.K. .Dearstine M. .Dottery P. .et al Particulate matter within the inferior vena cava. Echocardiography. 2008;25:803-804 [PubMed]journal. [CrossRef] [PubMed]
 
Black I.W. . Spontaneous echo contrast: where there's smoke there's fire. Echocardiography. 2000;17:373-382 [PubMed]journal. [CrossRef] [PubMed]
 
Deklunder G. .Lecroart J.L. .Savoye C. .et al Transcranial high-intensity Doppler signals in patients with mechanical heart valve prostheses: their relationship with abnormal intracavitary echoes. J Heart Valve Dis. 1996;5:662-667 [PubMed]journal. [PubMed]
 
Fibel K.H. .Barnes R.P. .Kinderknecht J.J. . Pressurized intravenous fluid administration in the professional football player: a unique setting for venous air embolism. Clin J Sport Med. 2015;25:e67-e69 [PubMed]journal. [CrossRef] [PubMed]
 
Palmon S.C. .Moore L.E. .Lundberg J. .et al Venous air embolism: a review. J Clin Anesth. 1997;9:251-257 [PubMed]journal. [CrossRef] [PubMed]
 
Wang A.Z. .Zhou M. .Jiang W. .et al The differences between venous air embolism and fat embolism in routine intraoperative monitoring methods, transesophageal echocardiography, and fatal volume in pigs. J Trauma. 2008;65:416-423 [PubMed]journal. [PubMed]
 
Zhao J. .Zhang J. .Ji X. .Li X. .Qian Q. .Xu Q. . Does intramedullary canal irrigation reduce fat emboli? A randomized clinical trial with transesophageal echocardiography. J Arthroplasty. 2015;30:451-455 [PubMed]journal. [CrossRef] [PubMed]
 
Huber-Lang M. .Brinkmann A. .Straeter J. .et al An unusual case of early fulminant post-traumatic fat embolism syndrome. Anaesthesia. 2005;60:1141-1143 [PubMed]journal. [CrossRef] [PubMed]
 
Saranteas T. .Kostopanagiotou G. .Panou F. . Focused assessed transthoracic echocardiography for the diagnosis of fat embolism in an orthopedic patient with hip hemiarthroplasty. J Cardiothorac Vasc Anesth. 2014;28:e40-e41 [PubMed]journal. [CrossRef] [PubMed]
 
Mitsuoka A. .Inoue Y. .Kume H. .Sugano N. .Morito T. .Muneta T. . Discrimination of types of venous emboli using Doppler ultrasound. Ann Vasc Surg. 2010;24:721-727 [PubMed]journal. [CrossRef] [PubMed]
 

Figures

Tables

References

Kerut E.K. .Dearstine M. .Dottery P. .et al Particulate matter within the inferior vena cava. Echocardiography. 2008;25:803-804 [PubMed]journal. [CrossRef] [PubMed]
 
Black I.W. . Spontaneous echo contrast: where there's smoke there's fire. Echocardiography. 2000;17:373-382 [PubMed]journal. [CrossRef] [PubMed]
 
Deklunder G. .Lecroart J.L. .Savoye C. .et al Transcranial high-intensity Doppler signals in patients with mechanical heart valve prostheses: their relationship with abnormal intracavitary echoes. J Heart Valve Dis. 1996;5:662-667 [PubMed]journal. [PubMed]
 
Fibel K.H. .Barnes R.P. .Kinderknecht J.J. . Pressurized intravenous fluid administration in the professional football player: a unique setting for venous air embolism. Clin J Sport Med. 2015;25:e67-e69 [PubMed]journal. [CrossRef] [PubMed]
 
Palmon S.C. .Moore L.E. .Lundberg J. .et al Venous air embolism: a review. J Clin Anesth. 1997;9:251-257 [PubMed]journal. [CrossRef] [PubMed]
 
Wang A.Z. .Zhou M. .Jiang W. .et al The differences between venous air embolism and fat embolism in routine intraoperative monitoring methods, transesophageal echocardiography, and fatal volume in pigs. J Trauma. 2008;65:416-423 [PubMed]journal. [PubMed]
 
Zhao J. .Zhang J. .Ji X. .Li X. .Qian Q. .Xu Q. . Does intramedullary canal irrigation reduce fat emboli? A randomized clinical trial with transesophageal echocardiography. J Arthroplasty. 2015;30:451-455 [PubMed]journal. [CrossRef] [PubMed]
 
Huber-Lang M. .Brinkmann A. .Straeter J. .et al An unusual case of early fulminant post-traumatic fat embolism syndrome. Anaesthesia. 2005;60:1141-1143 [PubMed]journal. [CrossRef] [PubMed]
 
Saranteas T. .Kostopanagiotou G. .Panou F. . Focused assessed transthoracic echocardiography for the diagnosis of fat embolism in an orthopedic patient with hip hemiarthroplasty. J Cardiothorac Vasc Anesth. 2014;28:e40-e41 [PubMed]journal. [CrossRef] [PubMed]
 
Mitsuoka A. .Inoue Y. .Kume H. .Sugano N. .Morito T. .Muneta T. . Discrimination of types of venous emboli using Doppler ultrasound. Ann Vasc Surg. 2010;24:721-727 [PubMed]journal. [CrossRef] [PubMed]
 
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