Safety and effects of volume loading during transesophageal echocardiography in the pre-procedural work-up for left atrial appendage closure

Background

In patients undergoing left atrial appendage (LAA) closure, an accurate sizing of the LAA is key to optimize device sizing, procedural success and reduce complications. Previous studies have shown that intraprocedural volume loading increases LAA dimensions and improves device sizing. However, the safety and effects on LAA and device sizing of administering a fluid bolus during pre-procedural transesophageal echocardiography (TEE) are unknown. The aim of this study was to determine the safety and impact on LAA dimensions and device sizing of an intravenous (IV) fluid bolus administered during TEE in the setting of the pre-procedural work-up for LAA closure.

Methods

The study included a total of 72 patients who underwent TEE to assess suitability for LAAC and received a 500 ml IV bolus of normal saline. The LAA landing zone (LZ) and depth were measured by TEE before and after volume loading, and these measurements were used to predict the device size implanted during a subsequent percutaneous LAAC procedure.

Results

There were no complications associated with volume loading. The baseline mean LZ was 19.6 ± 3.6 mm at 90^o, and 20.2 ± 4.1 mm at 135^o. Following fluid bolus, the maximum diameter increased 1.5 ± 1.0 mm at 90^o (p<0.001), and 1.3 ± 1.0 mm at 135^o (p<0.001). The baseline mean depth of the LAA was 26.5 ± 5.5 mm at 90^o, and 23.9 ± 5.8 mm at 135^o. After fluid bolus, the mean depth increased by 1.5 ± 1.8 mm (p<0.001) and 1.6 ± 2.0 (p<0.001), at 90^o and 135^o, respectively. Sizing based on post-bolus measurements of the LZ significantly improved the agreement with the final device size selection during the procedure in 71.0% of cases (vs. 42.0% with pre-bolus measurements).

Conclusions

Volume loading during ambulatory TEE as part of the pre-procedural work-up of LAAC is safe and significantly increases LAA dimensions. This strategy may become the new standard, particularly in centers performing LAAC with no TEE guidance, as it improves LAA sizing and more accurately predicts the final device size.

Passive leg raising test with minimally invasive monitoring: the way forward for guiding septic shock resuscitation?

Background

Swift and adequate fluid loading is a cornerstone of septic shock therapy. Yet, careful assessment of volume responsiveness and volume amount during the resuscitation process is a prerequisite. Both overzealous initial fluid administration and late fluid overload are harmful and may be associated with increased mortality.

Main body

Static (i.e., central venous or pulmonary artery occlusion) pressure readings are erroneous for monitoring fluid resuscitation and should be abandoned. Dynamic measurements (i.e., stroke volume and pulse pressure variation) better predict fluid responsiveness than static filling pressures but the conditions necessary for these parameters to correctly evaluate preload dependency are frequently not met. The passive leg raising maneuver as a means to alter biventricular preload in combination with real-time measurement of cardiac output changes is an easy-to-use, fast, relatively unbiased, and accurate bedside test to guide fluid management and to avoid fluid overload during early septic shock treatment. Moreover, PLR may also be particularly useful to assist various treatments that trigger fluid removal during the “de-resuscitation” phase of septic shock.

Conclusions

The passive leg raising maneuver in combination with real-time measurement of cardiac output changes is an easy-to-use, fast, relatively unbiased, and accurate bedside test to guide fluid management during septic shock.