Dyspnea and respiratory muscle strength in end-stage liver disease

Abstract

AIM:To investigate the prevalence of chronic dyspnea and its relationship to respiratory muscle function in end-stage liver disease. METHODS:Sixty-eight consecutive, ambulatory, Caucasian patients with end-stage liver disease, candidates for liver transplantation, were referred for preoperative respiratory function assessment. Forty of these (29 men) were included in this preliminary study after applying strict inclusion and exclusion criteria. Seventeen of 40 patients (42%) had ascites, but none of them was cachectic. Fifteen of 40 patients (38%) had a history of hepatic encephalopathy, though none of them was symptomatic at study time. All patients with a known history and/or presence of co-morbidities were excluded. Chronic dyspnea was rated according to the modified medical research council (mMRC) 6-point scale. Liver disease severity was assessed according to the Model for end-stage liver disease (MELD). Routine lung function tests, maximum static expiratory (Pemax) and inspiratory (Pimax) mouth pressures were measured. Respiratory muscle strength (RMS) was calculated from Pimax and Pemax values. In addition, arterial blood gases and pattern of breathing (VE: minute ventilation; VT: tidal volume; VT/TI: mean inspiratory flow; TI: duration of inspiration) were measured. RESULTS:Thirty-five (88%) of 40 patients aged (mean ± SD) 52 ± 10 years reported various degrees of chronic dyspnea (mMRC), ranging from 0 to 4, with a mean value of 2.0 ± 1.2. MELD score was 14 ± 6. Pemax, percent of predicted (%pred) was 105 ± 35, Pimax, %pred was 90 ± 29, and RMS, %pred was 97 ± 30. These pressures were below the normal limits in 12 (30%), 15 (38%), and 14 (35%) patients, respectively. Furthermore, comparing the subgroups of ascites to non-ascites patients, all respiratory muscle indices measured were found significantly decreased in ascites patients. Patients with ascites also had a significantly worse MELD score compared to non-ascites ones (P = 0.006). Significant correlations were found between chronic dyspnea and respiratory muscle function indices in all patients. Specifically, mMRC score was significantly correlated with Pemax, Pimax, and RMS (r = -0.53, P < 0.001; r = -0.42, P < 0.01; r = -0.51, P < 0.001, respectively). These correlations were substantially closer in the non-ascites subgroup (r = -0.82, P < 0.0001; r = -0.61, P < 0.01; r = -0.79, P < 0.0001, respectively) compared to all patients. Kaltsakas G et al . Dyspnea and liver disease tor of mMRC score was RMS (r = -0.51, P < 0.001). In the subgroup of patients without ascites this relationship becomes closer (r = -0.79, P < 0.001), whilst this relationship breaks down in the subgroup of patients with ascites. The disappearance of such a correlation may be due to the fact that ascites acts as a "confounding" factor. PaCO2 (4.4 ± 0.5 kPa) was increased, whereas pH (7.49 ± 0.04) was decreased in 26 (65%) and 34 (85%) patients, respectively. PaO2 (12.3 ± 0.04 kPa) was within normal limits. VE (11.5 ± 3.5 L/min), VT (0.735 ± 0.287 L), and VT/TI (0.449...

Acid-base disorders in liver disease

“…Even though several studies using standard techniques for evaluating acid-base equilibrium could not find any metabolic acid-base disorders, they reported the most well-established acid-base disorder in chronic liver disease, respiratory alkalosis, 30,31,[40][41][42] with a more pronounced hypocapnia in patients with severe liver disease or viral hepatitis. 37,43,44 While the reason for this commonly observed respiratory acidbase disorder is not ultimately clear, there are several theories and underlying conditions leading to dyspnoea and compensatory hyperventilation. 45,46 While massive ascites and/or hepatic hydrothorax 47 cause hypoxaemia and thus hyperventilation, hyperammonaemia and hepatic encephalopathy 48 induce hyperventilation per se.…”

Association Between Fatigue and Exercise Capacity in Patients With Chronic Liver Disease Awaiting Liver Transplantation

“…Significant correlations were found between dyspnea and fatigue. Previous study found significant correlations between chronic dyspnea and muscle fatigue (16,25) .…”

A scoping review to identify and map the multidimensional domains of pain in adults with advanced liver disease

“…58 Seven (18%) studies did not report the country where the research was conducted. 49,65,66,73,74,76,77 Study settings include inpatient (16; 37%), [45][46][47][48][50][51][52][53][54][55][56][57]59,60,79,87 outpatient (11; 26%), 58,61,63,67,70,72,75,77,82,84,85 and both in-and outpatient clinical settings (1; 2%). 76 Fifteen (35%) studies did not specify the patient setting.…”