THE USE OF LEFT VENTRICLE GLOBAL LONGITUDINAL STRAIN IN THE SEPTIC PATIENT
Each year there are 150,000 cases of sepsis in UK hospitals, resulting in approx. 44,000 deaths. Despite recent improvements in identification and management, it remains the leading cause of in-hospital death. Sepsis induced cardiomyopathy occurs in 14% of patients with sepsis, leading to significant morbidity and mortality.
In conventional echo, measurement of ejection fraction (EF) is commonly used for assessment of left ventricular (LV) function. However, EF measurements may not detect subtle cardiac dysfunction of septic patients. Studies have shown that LV global longitudinal strain (GLS) may be better at detecting early cardiac dysfunction in sepsis.
Over a 4 month period, septic patients admitted to intensive care of a large district general hospital were identified. GLS and LVEF were performed retrospectively. Images were acquired on GE S70 machines by a British Society Echocardiography (BSE) accredited Cardiac Physiologist. Those patients without suitable enough apical images to perform GLS / speckle tracking were excluded. Statistical significance was established using McNemar’s test.
In critically ill patients with sepsis and septic shock, does GLS compared with LV EF identify more patients with myocardial dysfunction?
13 patients meeting criteria were scanned. 10 (76.9%) patients had a preserved EF (≥ 55%) in the presence of concurrent severe sepsis. Where as only 4 (31%) patients had normal function measured by GLS. This was a statistically significant difference. (p=0.04, McNemar’s test).
Of the 4 patients that had normal function measured by GLS and LVEF, one patient was on inotropes and one patient had cirrhosis which is associated with a hyperdynamic circulation. These factors may have increased the measured function for these patients.
Critically ill patients with sepsis were significantly more likely to have low GLS compared to a reduced EF. This data suggests that measurements of GLS in septic patients may allow earlier detection of LV dysfunction.
This may help identify patients who are critically ill wth sepsis as well as help guide fluid management and inotropic support.. A further larger study is planned to investigate the use of GLS in critically ill patients with sepsis.