Trauma Resuscitation Using Echocardiography in a Deployed Military Intensive Care Unit

Abstract

Casualties with severe traumatic injury frequently suffer haemodynamic instability. There is interest in the use of transthoracic echocardiography (TTE) to assess haemodynamic status in intensive care resuscitation. We describe a feasibility study of focused TTE (fTTE) echocardiography in trauma resuscitation in a deployed military setting. fTTE was performed on patients admitted to ICU following severe injury. Data were collected on TTE view availability, LV function, volume status, and inferior vena cava (IVC) dimensions. Doppler of the LV outflow tract was performed to provide a velocity time integer (LVOT VTi) as an indicator of preload. Twenty-three patients were recruited, and 48 individual studies performed. TTE windows available were: parasternal long axis-68%, parasternal short axis-66%, apical 4-chamber-64%, subcostal-66%. IVC imaging was possible in 85%, and LVOT VTi Doppler in 37%. The mean maximal IVC diameter in volume-optimised patients (Group 1, n=19) was 2.07 cm (±0.07), compared with 1.47 (±0.06) in the hypovolaemic cohort (Group 2, n=23). The mean minimum IVC diameter in Group 1 was 1.93(±0.07) vs 1.03(±0.08) in Group 2. IVC collapsibility was 3.16% (±1.61%) in Group 1 vs 30.81%(±1.62) in Group 2. In 12%, profound hypovolaemia with systolic LV cavity obliteration was noted. fTTE suggested hypovolaemia in 69% of patients on admission to the study. Of patients arriving on the ICU following damage-control resuscitation only 31% were volume-optimised. fTTE led to a change in volume management strategy in 47% of cases. This study demonstrates, for the first time in a deployed military setting, that intensivist-delivered fTTE is feasible and changes resuscitation strategy in almost half of patients admitted to a deployed ICU.

Keywords

Focused transthoracic echocardiography inferior vena cava variability fluid resuscitation myocardial injury battlefield trauma

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