Published online Jul 26, 2020. doi: 10.4330/wjc.v12.i7.351
Peer-review started: February 29, 2020
First decision: April 7, 2020
Revised: May 11, 2020
Accepted: June 17, 2020
Article in press: June 17, 2020
Published online: July 26, 2020
Processing time: 146 Days and 5.9 Hours
Patients undergoing cardiac surgery particularly those with comorbidities and frailty, experience frequently higher rates of post-operative morbidity, mortality and prolonged hospital length of stay. Muscle mass wasting seems to play important role in prolonged mechanical ventilation (MV) and consequently in intensive care unit (ICU) and hospital stay.
To investigate the clinical value of skeletal muscle mass assessed by ultrasound early after cardiac surgery in terms of duration of MV and ICU length of stay.
In this observational study, we enrolled consecutively all patients, following their admission in the Cardiac Surgery ICU within 24 h of cardiac surgery. Bedside ultrasound scans, for the assessment of quadriceps muscle thickness, were performed at baseline and every 48 h for seven days or until ICU discharge. Muscle strength was also evaluated in parallel, using the Medical Research Council (MRC) scale.
Of the total 221 patients enrolled, ultrasound scans and muscle strength assessment were finally performed in 165 patients (patients excluded if ICU stay < 24 h). The muscle thickness of rectus femoris (RF), was slightly decreased by 2.2% [(95% confidence interval (CI): - 0.21 to 0.15), n = 9; P = 0.729] and the combined muscle thickness of the vastus intermedius (VI) and RF decreased by 3.5% [(95%CI: - 0.4 to 0.22), n = 9; P = 0.530]. Patients whose combined VI and RF muscle thickness was below the recorded median values (2.5 cm) on day 1 (n = 80), stayed longer in the ICU (47 ± 74 h vs 28 ± 45 h, P = 0.02) and remained mechanically ventilated more (17 ± 9 h vs 14 ± 9 h, P = 0.05). Moreover, patients with MRC score ≤ 48 on day 3 (n = 7), required prolonged MV support compared to patients with MRC score ≥ 49 (n = 33), (44 ± 14 h vs 19 ± 9 h, P = 0.006) and had a longer duration of extracorporeal circulation was (159 ± 91 min vs 112 ± 71 min, P = 0.025).
Skeletal quadriceps muscle thickness assessed by ultrasound shows a trend to a decrease in patients after cardiac surgery post-ICU admission and is associated with prolonged duration of MV and ICU length of stay.
Core tip: Muscle mass wasting may occur in post-cardiac surgery patients affecting outcome. We assessed the clinical significance of muscle mass in post-cardiac surgery after intensive care unit (ICU) admission. Sonographic assessment of quadriceps muscle thickness was performed to 165 post-cardiac surgery patients for 7 d or until ICU discharge. The results of the study showed a trend to a decreased muscle mass in post-cardiac surgery patients. There was also an association between muscle mass andduration of mechanical ventilation support and ICU length of stay. Sonographic assessment seems to be a valid method to quantify quadriceps muscle mass in patients after cardiac surgery.