An Assessment of the Diagnostic Value in Syncope Workup: A Retrospective Study

Background

Patients with syncope often undergo costly testing, despite current guidelines and data supporting the contrary.

Objective

To determine the diagnostic value through positivity rate of electrocardiogram (EKG), computed tomography (CT) of the brain, magnetic resonance imaging (MRI) of the brain, transthoracic echocardiogram, nuclear and pharmacologic cardiac stress test, tilt table test and carotid ultrasound in patients diagnosed with syncope.

Methods

This is a retrospective study of 10,036 adults presenting to the emergency department or hospitalized with a primary diagnosis of syncope at 8 acute care facilities in the southwest United States from January 1, 2019, to December 31, 2019. A chi-square analysis was performed for each testing modality to evaluate for a statistically significant difference. The cost of each test was estimated based on published national averages per Medicare.

Results

Of our sample, 903 patients (9%) received a test that yielded any positive finding. The results in the order of highest percent positivity rate to lowest were EKG (5.7%), carotid ultrasound (4.84%), transthoracic echocardiogram (2.56%), tilt table test (1%), MRI brain (0.99%), CT brain (0.82%) and cardiac stress test (0.09%). The total sum spent on testing was estimated at $43,347,332. Only $489,170 of this total was spent on a positive test. If this data is expanded to the 6,146 hospitals across the United States, a yearly $33 billion are wasted on syncope workups.

Conclusion

Costly testing continues to be performed on syncope patients despite guidelines discouraging testing. The necessity of these tests should be carefully evaluated for each patient based on diagnostic value.

Gravity Fluid Flow More Accurately Reflects Joint Fluid Pressure Compared With Commercial Peristaltic Pump Systems in a Cadaveric Model

PURPOSE

To evaluate intra-articular fluid pressures and joint compliance generated by fluid management systems on cadaveric shoulders and knees under simulated arthroscopic conditions, and to compare joint compliance between knee and shoulder specimens.

METHODS

Intra-articular pressures of 5 cadaver shoulders and 5 knees were recorded for 4 arthroscopic pumps (Stryker FloControl, Stryker CrossFlow, Arthrex DualWave, DePuy Mitek FMS Duo) and a gravity feed system. Each specimen was tested 6 times with a pressure transducer for 2 minutes at 0, 25%, and 50% suction. The average pressures were analyzed with 1-way analysis of variance and Tukey's honestly significant difference tests (P < .05).

RESULTS

At all suction levels, all pumps exhibited significantly greater pressure than gravity feed (P = .001 to P < .001). At both 25% and 50% suction, FloControl displayed significantly greater pressures (P_max 160.44 mm Hg) than the other pumps or gravity feed (P_max 46.9 mm Hg). CrossFlow had the lowest net percentage error (36.8%, 18.4 mm Hg) when compared with the standard pressure of 50 mm Hg, followed by gravity feed. All pumps had large initial overshoot (ie, P_initial CrossFlow 99.4 mm Hg) followed by settling time, whereas gravity feed did not (P_initial 55.2 mm Hg).

CONCLUSIONS

Gravity feed is an accurate, reliable delivery method for arthroscopic fluid with minimal overshoot and lower intra-articular pressure ranges than commercial pump systems. There was no evidence of plastic deformation of the joint capsule, because capsular compliance increased linearly in both knee and shoulder specimens throughout testing within the established safe range of intra-articular pressures.

CLINICAL RELEVANCE

Arthroscopic flow management systems produce maximal and overshoot pressures that are not seen with gravity flow. Surgeons should understand intra-articular pressure and fluid delivery behavior during shoulder and knee arthroscopy to adapt to the variability and higher maximal pressures when using pump systems. Maintaining appropriate pressure could prevent fluid extravasation and possible neuromuscular dysfunction.