Comparison of surface electromyography in respiratory muscles of healthy and liver disease patients: preliminary studies

Model for End-Stage Liver Disease Score Before Hepatic Transplantation and Root Mean Square of the Diaphragmatic Domes Affect Postoperative Extubation Time

INTRODUCTION

The liver transplantation procedure, in addition to its prolonged surgical time, also predisposes to complications such as changes in respiratory mechanics, lung volumes, and gas exchange.

OBJECTIVE

This study aims to verify if clinical factors related to the recipient, namely immediate pretransplant Model for End-Stage Liver Disease (MELD) score, surgical time, and root square metric (RMS) of the diaphragmatic domes, affect the extubation time after liver transplantation.

METHOD

A prospective study, with a sample collected for convenience, gathered age (years), sex (male or female), MELD score immediately prior to transplantation (without the addition of special situation scores), and surgical time and time for extubation (in minutes). The latter were obtained from the physiotherapy team records, and surface electromyography was performed within 30 minutes after elective extubation, by a single researcher, with supplemental oxygen support, maintaining SpO₂ ≥ 95% and following protocol of positioning and acquisition of electromyographic signals based on the study of Oliveira et al (2012).

RESULTS

For the 21 patients studied, the RMS of the left dome showed a moderate-intensity correlation (-0.56) with the time of extubation, and linear multiple regression model the left dome (P = .013) and preoperative MELD score (P = .048) showed significant correlation with extubation time.

CONCLUSION

The preoperative MELD score and the RMS values of the left dome significantly correlate with the time for patient extubation after liver transplantation, showing the effect of previously acquired muscle weakness and preoperative MELD score on postoperative outcome.

Diaphragm Muscle Surface Electromyography in Patients Submitted to Liver Transplant and Eligible for Extubation

INTRODUCTION

Liver disease induces many organic and metabolic changes, leading to malnutrition and weight and muscular function loss. Surface electromyography is an easily applicable, noninvasive study, through which the magnitudes of the peaks on the charts depict voluntary muscle activity.

AIM

To evaluate the diaphragmatic surface electromyography of postoperative liver transplantation subjects.

METHODS

Subjects were patients who underwent liver transplantation and extubation in the Clinical Hospital of State University of Campinas. Electromyography data were collected with support pressure of ≤10 cm H₂O, Glasgow Coma Scale = 11, and minimum dosages of vasoactive drugs, and data were collected again 30 minutes after extubation. Signal collection was performed with sEMG System Brazil SAS1000V3 electromyograph and electrode stickers. Statistical analysis was performed using R software.

RESULTS

The average time of surgery was 345.36 ± 125.62 minutes. Time from spontaneous mode until extubation was 417.14 ± 362.97 minutes. The RMS (root mean square) values of the right and left domes in spontaneous mode with minimal ventilation parameters were 26.68 ± 10.92 and 26.55 ± 10.53, respectively, and the RMS values after extubation were 31.93 ± 18.69 to 34.62 ± 13.55, for right and left domes. The last calculated pretransplant Model for End-stage Liver Disease score averaged 19.64 ± 8.41.

CONCLUSION

There were significant differences between the RMS of the diaphragm domes under mechanical ventilation and after extubation, showing lower effectiveness of the diaphragm muscle against resistance, without the aid of positive pressure and the existing overload of the left dome.

Association Between Dyspnea and Severity of Liver Disease in Patients in the Pre-transplantation Period-A Pilot Study

BACKGROUND

Liver transplantation is indicated at the end stage of chronic liver failure, and severity of disease will determine the precocity of this happening. At this stage, the presence of chronic dyspnea is one of several manifestations of progression of the disease, which leads the patient to inactivity. A rehabilitation program can positively influence the evolution of liver transplant recipients. The objective of this study was to establish an association between the perception of dyspnea and the severity of liver disease in patients at a single center of a Brazilian liver pre-transplantation clinic.

METHODS

Measurements were performed at a liver pre-transplantation clinic. The severity of liver disease was assessed with the use of the Model for End-Stage Liver Disease (MELD) score, and dyspnea was assessed with the use of a modified Medical Research Council scale of dyspnea (mMRC).

RESULTS

Men had a higher prevalence of viral hepatitis. Dyspnea was reported only during intense exercise. Duration of disease and MELD score showed medians of 49 months and 20, respectively.

CONCLUSIONS

We found no correlation between mMRC and the MELD score. In addition, no correlation was found between duration of disease and MELD score or mMRC.

Exercise manual for liver disease patients

AIM: To increase inspiratory muscle strength and improve the quality of life of candidates for liver transplantation.

METHODS: Twenty-three candidates for liver transplantation participated in the control group and 14 made up the intervention group. The control group consisted of 18 men and 5 women, body mass index (BMI) 27.3 ± 4.5 kg/m² and Model for End-Stage Liver Disease (MELD) 18.2 ± 6.1. The intervention group consisted of 11 men and 3 women, BMI 28.6 ± 5.4 kg/m² and MELD 18 ± 4.5. The presence or absence of ascites was identified in the first patient evaluation and after three months. We evaluated maximal inspiratory pressure (MIP) and maximal expiratory pressure, spirometry, root mean square (RMS) of diaphragm and rectus abdominis, and the quality of life. The exercises were performed daily by patients at home for three months and were supervised at distance monthly. The manual consisted of diaphragmatic breathing exercises, diaphragmatic isometric exercise, Threshold IMT^®, lifting upper limbs with a bat and strengthening the abdomen.

RESULTS: There was significant difference (P = 0.01) between the first (initial) and the third month (final) MIP in the control group and in the intervention group, but there was no difference (P = 0.45) between the groups. The RMS of the diaphragm was lower (P = 0.001) and the functional capacity was higher (P = 0.006) in the intervention group compared to the control. The general health and mental health domains received higher scores after three months in the control group (P = 0.01) and the intervention group (P = 0.004), but there was no significant difference between them. The comparison between the presence of initial ascites with the presence of ascites was performed after three months in the control group (P = 0.083) and intervention group (P = 0.31). There was no significant difference, in relation to the presence of ascites after three months between groups (P = 0.21). In the intervention group, patients with ascites at the end of the time period had decreased scores on the social aspects SF-36 domain (P = 0.023) compared to those who had no ascites.

CONCLUSION: The proposed exercises provide an increase in the inspiratory muscle strength and improve functional capacity, consequently bettering the quality of life of liver disease patients.

Profile of respiratory evaluation through surface electromyography, manovacuometry, and espirometry in candidates on the liver transplant waiting list

INTRODUCTION

Electromyography (EMG) is the examination of skeletal muscle membrane electrical activity in response to physiologic activation. In healthy muscles, the square root (root mean square [RMS] is related to the amplitude of the obtained signal. Respiratory muscles are studied, especially those important for compliance, the diaphragm and the rectus abdominis. An evaluation to detect respiratory muscle deficits among liver disease patients on the waiting list for transplantation may serve as an alternative to providing specific treatments reducing the possibility of respiratory complications after transplantation.

OBJECTIVE

To study muscle activity by evaluating respiratory and surface EMG of the right diaphragm and right rectus abdominis muscles in patients on the liver transplant waiting list.

METHOD

Respiratory evaluation of muscle strength (maximum inspiratory pressure [MIP] and maximum expiratory pressure [MEP]) with a manometer -300, +300 from Gen-air; spirometry with Easyware Spirometer version 2.20; pulse oximetry with Nonim oximeter; Model for End-Stage Liver Disease (MELD) score as well as surface EMG of the diaphragm and rectus abdominis muscles from EMG/Brazil were applied in healthy and liver diseased subjects.

RESULTS

The 87 liver disease patients showed a mean age of 53.9 ± 7.3 years, mean body mass index of 28.21 ± 5.04 kg/m2 with 24.14% smokers (n = 21) and 43.68% physically active (n = 38 p) showing Diaphragm RMS of 61.05 ± 68.48 μV; rectus abdominis RMS of 45.28 ± 53.82 μV; MEP of 100.28 ± 27.85 cm H(2)O; and MIP of 92.41 ± 29.77 cm H2O. The average MELD of studied patients was 16.5 ± 0.71.

CONCLUSION

The respiratory profiles of patients on the liver transplant waiting list concerning muscle support were precarious owing to ascites and motor adynamia.