Prolonged Hypoxia After Aspiration

A 63-year-old woman presented to the ED via EMS from her nursing home with hypoxia after a reported aspiration event. She had recently been discharged from the hospital to a nursing home after suffering from a left-sided putamen hemorrhagic stroke that left her with right-sided hemiplegia. The patient began to complain of shortness of breath the day prior to presentation. There was concern for repeated aspiration events. When EMS arrived, she had oxygen saturations in the 60’s, which improved to the mid-90’s with pre-hospital CPAP.

 

Initial VS: HR 96, BP 160/96, RR 20, SpO2 99% on BiPAP, Temp (rectal) 99.6F

 

Physical exam revealed a woman sitting up in bed, speaking in full sentences. There were right-sided rhonchi present. Heart exam revealed regular rate and rhythm. Neurologic exam revealed a dense right-sided hemiplegia. There was trace bilateral non-pitting edema.

 

IV access was established and labs were sent. CXR was called for, and the clinicians performed a bedside ultrasound looking at the lungs and heart.

 

Here is a view of the right lung:

You can see that there are b-lines present and a general absence of a-lines. This is consistent with a “wet” lung. This could be from pneumonia, pulmonary edema, pulmonary contusion, etc.

 

Here is a view of the left lung:

Notice how this appears different. There is an a-line predominance with the absence of b-lines.

 

Because the right side looked wet and the left side appeared dry, the clinicians assumed this was representative of pneumonia.

 

Cardiac imaging was difficult in this patient given her body habitus, and because she could not tolerate lying down in bed whatsoever. Here is the best view that could be obtained:

 

This is a parasternal long view. Even though the image quality is not the best, the clinicians took a few things away from this scan: (1) It appears as there is generally good left ventricular systolic function, and (2) the right ventricle did not appear to be enlarged.

 

Below is the CXR that was obtained:

The clinicians interpreted the CXR as having a right lung infiltrate consistent with aspiration pneumonia and started the patient on antibiotics. She was feeling improved with the BiPAP. The MICU team was called, and plans were made to admit the patient to the ICU for ongoing management.

 

Just before going upstairs, one of the clinicians caring for the patient decided to look in the lower extremities for DVT. Even though the etiology of the hypoxia seemed to clearly be aspiration pneumonia, the patient was immobilized and at high risk of developing a clot.

 

Here is a view of the left common femoral vein:

You can see that the vein is easily compressible.

 

Here is the left popliteal:

Again, it is easily compressible.

 

Here is the right common femoral vein:

 

Part of the vein is easily compressible, but distal to the greater saphenous take off, the vein becomes non-compressible. This is consistent with a DVT.

 

Here is the right popliteal:

 

This is also non-compressible.

 

This finding of DVT made the clinicians concerned that the patient’s hypoxia was not from aspiration, but from a PE. The clinicians knew that management of PE in this patient would be a difficult decision given her recent hemorrhagic stroke, and they decided to proceed with a CT pulmonary angiogram to see if she indeed had a PE.

 

Here are some of the images that were obtained from the CT:

 

The radiologist commented on two findings: (1) Extensive pulmonary embolus in both lower lobes, left greater than right, and (2) right pulmonary consolidation and bilateral patchy ground glass opacities consistent with infection.

 

Given her recent hemorrhagic stroke, the stroke team was consulted to help decide on a management strategy. A CT of her head was obtained to evaluate the prior area of hemorrhage before starting any anticoagulation. After the CT scan, the patient was started on heparin with plans to repeat the head CT in 6 hours and monitor with frequent neurologic checks in the ICU. She remained hemodynamically stable in the ED.

 

She initially was stable in the ICU without development of worsening neurologic symptoms, however, over the course of a few days, her respiratory status declined, and she was intubated. She remained intubated for 12 days. After extubation, she was transferred down to the floor and bridged to warfarin for anticoagulation. An IVC filter was placed given the extensive clot burden in her lower extremity. She did not develop any further neurologic deficits while in the hospital and was discharged to sub-acute rehab.

 

We think that there are two main lessons to take away from this case: (1) Not everyone with PE will have evidence of right heart strain on cardiac ultrasound; in fact, a minority of patients with PE will have evidence on cardiac ultrasound.^1-2 (2) Sometimes patients have more than one thing going on, and the diagnosis that makes the most since (aspiration pneumonia in this case) is not always the most deadly. When ultrasound is used at the bedside, it can assist in making those difficult diagnoses. In someone who PE is on the differential, we advocate looking at the lower extremities to look for DVT as this can help cinch a diagnosis.

 

Bottom Line:

1. Only 30-40% of those with PE will have evidence on cardiac ultrasound.
2. When considering PE, also look at the lower extremities for DVT. This can help cinch difficult diagnoses.