BLOG: Examine postoperative patients the same way every time, look for DVT

ByDaniel J. Acevedo, PA-C

In medicine, there are good days and bad days. There are times in clinics where everything seems to go right: all the postoperative patients are doing well, no one has complaints, the injections go smoothly and the diagnoses are straightforward. Then, there are days when nothing seems to go right. Unfortunately, those days, while rare, stick in our minds like an indelible mark. We become frustrated and we question our purpose and whether we are even helping.

Most days fall under the proverbial “bell curve:” easy patients, difficult patients, straightforward cases, standard injections, casts, etc. It all averages out to a standard day. Those days are made up of small wins and losses. The following is a story of a big win that any health care provider, particularly young physician assistants, can find useful.

Patient presents pain after knee arthroscopy

He was the last patient of the day. It was a good day in clinic. It was December, and the Christmas spirit was in full swing. We know in medicine that our lives and work does not stop even though it is a holiday. However, the general mood is always more upbeat, more positive; even those bad days are never that bad when you have the holidays to look forward to. It is also a time when many patients seem to schedule their elective orthopedic surgeries.

This particular patient had a standard knee arthroscopy with a partial medial meniscectomy 10 days prior. He was young and physically active. He had no comorbid conditions. I asked the medical assistant helping me, “How is he doing?” She replied, “He is doing fine.” I thought this will be an easy last patient of the day. I walked into the room and I did my standard history and review of systems. He was doing well. Pain at the medial joint line was already better. He was ambulating unassisted. He was not taking narcotics. He had no complaints of chest pain or shortness of breath. He was even taking his prophylactic aspirin with food daily. Then I asked him, “Any calf pain?” He looked at me, puzzled. He replied, “Yeah, in fact, I do. It is probably the only pain I have. It is this burning, deep pain. Why is that happening?”

Signs of deep vein thrombosis

Deep vein thrombosis (DVT) is an elusive phenomenon in orthopedics. We memorize Virchow’s triad. We understand the inherent risks of orthopedic surgery and how every surgical patient is at higher probability of forming a blood clot in the lower leg. I was always taught to examine every postoperative patient the same: check the skin, assess the wound, look for swelling and erythema, and squeeze the calf.

But not all DVTs present this way. There could be only pain. Some patients have a swollen calf and prominent vessels. Sometimes it is just erythematous and warm. Some have a mix of signs or symptoms. Many may have no symptoms at all. How do we tease out the standard postoperative signs and symptoms and the diagnosis of DVT? It turns out there is no easy way clinically. Clinical information including history and physical is insufficient to make this diagnosis. Even in a patient with a low pretest probability via a Well’s criteria score should be screened with at least a D-Dimer.

Deep vein thrombosis is a documented medical complication of knee arthroscopy. The condition rarely causes pulmonary embolism unless it propagates to the proximal deep veins, which may happen as often as 25% of the time. It has been reported to be as high as 17.9% after knee arthroscopy, when screening asymptomatic patients, and as low as 0.4% when diagnosed clinically. This number is under debate, and the incidence of symptomatic venous thromboembolism remains uncertain. Risk factors include a prior history of DVT, obesity, cancer, use of oral contraceptives and increased age. Anderson and Spencer categorized the 10 most common causes of DVT with age greater than 40 years being number one.

Ways to diagnose DVT

Reporting also has been difficult given the variability in identification and reporting. Some providers employ venography and pulmonary angiography, while others use CT and Doppler ultrasound. Doppler ultrasound is the most common method of diagnosis. It is a safe, effective, and widely documented test. Technically adequate ultrasound studies have a sensitivity and specificity of 95% and 100%, respectively. The addition of a negative D-dimer, while more invasive, also will decrease the probability of the diagnosis of venous thromboembolism. If there is high clinical suspicion, a negative Doppler ultrasound, negative D-dimer and a high pre-test probability using Well’s Criteria, a follow-up study should be ordered. A positive test is diagnostic.

Inevitably this gentleman did well. I prolonged his postoperative visit by sending him to get an ultrasound but we diagnosed a potentially fatal complication. There are many lessons I have learned from this visit. Always examine your postoperative patients the same way every time. If you are unfamiliar examining postoperative patients, find a more experienced provider and ask for his or her help in questionable situations in the diagnosis of DVT. Keep a high index of suspicion, especially in older patients with recent history of lower extremity surgery. Use objective tools, such as Well’s criteria, simple blood work and Doppler ultrasounds in your diagnostic armamentarium. Always keep the health of your patients in the forefront of your mind.

References:

Patel, et al. Deep vein thrombosis. Medscape. http://emedicine.medscape.com/article/1911303-overview#showall

McKeon, et al. Knee Arthroscopy. Spinger. 2009.

Daniel J. Acevedo, PA-C, is a board-certified physician assistant who practices at the Orthopaedic Center of Central Virginia in Lynchburg, Va. His research interests include physician assistant education, osteoarthritis and periprosthetic joint infections.

Disclosure: Acevedo reports no relevant financial disclosures.