Background
Methods
Study design and population
Randomization
Intervention
Outcomes
Muscle layer thickness (MLT)
Muscle strength
Functional outcomes
Patient satisfaction
Statistical analysis
Results
Patients
NMES group (n = 27) | Control group (n = 27) | |
---|---|---|
Age, mean (SD), y | 63.3 (15.5) | 69.7 (13.1) |
Male sex, no. (%) | 18 | 20 |
Body mass index, mean (SD) | 27.6 (3.7) | 27.7 (4.6) |
SAPS II at postoperative day 1, median (range) | 26.0 (7–46) | 24.0 (7–47) |
SOFA at postoperative day 1, median (range) | 9.0 (1–15) | 7.0 (1–11) |
Period ventilated, median (range), d
a
| 2 (1–7) | 2 (1–15) |
ICU length of stay, median (range), d
b
| 6 (3–23)
c
| 7 (3–213)
c
|
ICU readmission, no. (%) | 4 (14.8) | 3 (11.1) |
ICU readmission, median (range), d
b
| 2 (1–35) | 6 (1–41) |
Hospital length of stay, median (range), d
b
| 22 (4–84)
d
| 19 (9–213)
d
|
Mortality, no (%) | ||
in the ICU | 1 (3.7) | 3 (11.1) |
at the surgical ward | 0 | 0 |
Single surgical procedure, no. (%)
e
| 17 (63.0) | 17 (63.0) |
Double surgical procedure, no. (%)
e
| 7 (25.9) | 7 (25.9) |
Triple surgical procedure, no. (%)
e
| 3 (11.1) | 3 (11.1) |
Surgery type, no. of procedures (% in relation to total no. of procedures) | ||
Aortic valve replacement | 9 (22.5) | 11 (27.5) |
Coronary artery bypass grafting | 11 (27.5) | 8 (20) |
Heart transplantation | 6 (15) | 5 (12.5) |
Other cardiothoracic surgery type
f
| 4 (10) | 4 (10) |
Mitral valve replacement | 2 (5) | 5 (12.5) |
Mitral valve reconstruction | 4 (10) | 3 (7.5) |
Tricuspid valve reconstruction | 3 (7.5) | 2 (5) |
Bentall procedure | 1 (2.5) | 2 (5) |
Comorbidities present in 96.3 % of the study population, no. (%) | ||
Coronary heart disease | 12 (44.4) | 8 (29.6) |
Hypertension | 9 (33.3) | 7 (25.9) |
Myocardial infarction | 7 (25.9) | 4 (14.8) |
Atrial fibrillation | 2 (7.4) | 8 (29.6) |
Diabetes | 5 (18.5) | 4 (14.8) |
Obesity | 3 (11.1) | 6 (22.2) |
Chronic obstructive pulmonary disease | 6 (22.2) | 3 (11.1) |
Hyperlipidemia | 4 (14.8) | 4 (14.8) |
Malignoma | 2 (7.4) | 5 (18.5) |
Carotid artery stenosis | 2 (7.4) | 2 (7.4) |
Patients receiving medication in the ICU, no. (%) | ||
Opioids | 26 (96.3) | 26 (96.3) |
Insulin | 25 (92.6) | 26 (96.3) |
Dobutamine | 21 (77.8) | 17 (63) |
Noradrenaline | 18 (66.7) | 18 (66.7) |
Glucocorticoids | 11 (40.7) | 6 (22.2) |
Benzodiazepines | 6 (22.2) | 6 (22.2) |
Neuromuscular blockers | 4 (14.8) | 2 (7.4) |
Intake days, median (range), d | ||
Opioids | 3 (1–10) | 3 (1–14) |
Insulin | 4 (1–9) | 4 (1–14) |
Dobutamine | 4 (2–12) | 5 (1–14) |
Noradrenaline | 2 (1–9) | 4.5 (1–14) |
Glucocorticoids | 3 (1–7) | 3.5 (1–14) |
Benzodiazepines | 1 (1–4) | 1 (1–9) |
Neuromuscular blockers | 1 (1–1) | 1 (1–1) |
Dose, median (range), μg/kg/min | ||
Dobutamine | 2.78 (0.52–7.59)
g
| 4.12 (0.82–10.53)
g
|
Noradrenaline | 0.07 (0.01–0.54)
h
| 0.12 (0.002–0.88)
h
|
NMES
Muscle layer thickness (MLT)
Estimate of MLT in cm (95 % CI) |
P value | |
---|---|---|
Intercept | 3.87 (3.58 to 4.15) | <0.001 |
Postoperative day | −0.08 (−0.11 to −0.06) | <0.001 |
Control group | Reference | . |
NMES group | −0.18 (−0.59 to 0.23) | 0.38 |
Postoperative day × Control group | Reference | . |
Postoperative day × NMES group | 0.02 (−0.01 to 0.06) | 0.21 |
Daily fluid balance in the ICU | −0.04 (−0.08 to 0.01) | 0.09 |
Estimate of MLT in cm (95 % CI) |
P value | |
---|---|---|
Intercept | 3.26 (2.99 to 3.52) | <0.001 |
Preoperative day | Reference | . |
First postoperative day | 0.41 (0.24 to 0.59) | <0.001 |
ICU discharge | 0.18 (−0.004 to 0.37) | 0.055 |
Hospital discharge | −0.28 (−0.49 to −0.06) | 0.01 |
Control group | Reference | . |
NMES group | −0.16 (−0.49 to 0.16) | 0.32 |
Muscle strength
Estimate of mean MRC in pointsa (95 % CI) |
P value | |
---|---|---|
Intercept | 4.10 (3.80 to 4.39) | <0.001 |
Postoperative day | 0.02 (−0.02 to 0.05) | 0.40 |
Control group | Reference | . |
NMES group | −0.45 (−0.88 to −0.03) | 0.04 |
Postoperative day × Control group | Reference | . |
Postoperative day × NMES group | 0.09 (0.03 to 0.14) | 0.002 |
Estimate of mean MRC in pointsa (95 % CI) |
P value | |
---|---|---|
Intercept | 4.69 (4.45 to 4.93) | <0.001 |
Preoperative day | Reference | . |
First postoperative day | −0.57 (−0.78 to −0.36) | <0.001 |
ICU discharge | −0.27 (−0.48 to −0.06) | 0.01 |
Hospital discharge | 0.10 (−0.15 to 0.35) | 0.43 |
Control group | Reference | . |
NMES group | 0.01 (−0.26 to 0.28) | 0.92 |
Estimate of mean MRC in kilogram-force (kgf) (95 % CI) |
P value | |
---|---|---|
Intercept | 30.18 (25.63 to 34.73) | <0.001 |
Preoperative day | Reference | . |
First postoperative day | −11.55 (−13.98 to −9.11) | <0.001 |
ICU discharge | −8.00 (−10.47 to −5.52) | <0.001 |
Hospital discharge | −4.00 (−6.90 to −1.09) | 0.008 |
Control group | Reference | . |
NMES group | 0.89 (−5.16 to 6.94) | 0.77 |
Functional outcomes
Preoperative day | ICU discharge | Hospital discharge |
P for change from preoperative day to hospital discharge | |
---|---|---|---|---|
Average mobility level, median (range) | 12 (12–12) | 2 (0–11)a
| 12 (8–12)b
| 0.04 |
FIM score, median (range) | 125.0 (119–126) | 122.0 (82–126) | 0.02 | |
Timed Up and Go Test, median (range) | 11.5 (7–20) | 11.5 (1–28) | 0.24 | |
MCS-12, median (range) | 52.82 (25.05–64.63) | 51.91 (29.42–64.08) | 0.88 | |
PCS-12, median (range) | 40.02 (17.91–61.61) | 32.58 (27.46–45.90) | 0.53 |
Patient satisfaction
Discussion
Muscle layer thickness (MLT)
Muscle strength
Functional outcomes
Limitations
Outlook
Conclusions
Key messages
-
The NMES intervention had no effect on muscle layer thickness, but was associated with a higher rate in regaining muscle strength during the ICU stay.
-
Patients regained preoperative levels of muscle strength evaluated with the MRC scale by hospital discharge, but still had residual functional disability. This was independent of group allocation.
-
The postoperative decrease in muscle layer thickness is not only due to loss of muscle mass, but also to reduction of intramuscular edema.