Dados do Resumo

Título

DIAPHRAGMATIC EVALUATION WITH COMPUTED TOMOGRAPHY AND CORRELATION WITH INSPIRATORY STRENGHT IN PATIENTS WITH LUNG CANCER

Introdução

Low muscle mass in lung cancer patients is an indicator of an unfavorable prognosis and can be associated with a higher risk of complications. The ventilatory muscles can also be affected by reduced strength and muscle mass. The diaphragm is the main inspiratory muscle and the literature on diaphragmatic assessment with computed tomography and its correlation with strength in lung cancer patients is still scarce.

Objetivo

The primary objectives are to describe the dimensions of the diaphragm and check whether its thickness correlates with respiratory muscle strength measurements, and the secondary objectives are to assess the correlation with overall muscle strength, lung function, fatigue and length of stay.

Métodos

This is a cross-sectional study with prospective data collection, submitted to the Research Ethics Committee of the AC Camargo Cancer Center and approved by opinion no. 31166/21. The study included patients diagnosed with lung cancer and excluded those with lung metastases or metastatic tumors; patients with other previous cancer diagnoses, who did not agree to take part in the study or who could not be assessed. Diaphragm dimensions were assessed using computed tomography - performed up to three months before the evaluation - ventilatory muscle strength (maximum inspiratory pressure and maximum expiratory pressure) using manovacuometry and total strength using dynamometry. To assess fatigue, we used the Brief Fatigue Inventory (BFI) questionnaire. The rest of the data was extracted from the electronic medical record. The data was added to a database using REDCap software, and Spearman's correlation coefficient was used for statistical analysis, with a significance level of 5%.

Resultados

352 patients underwent surgical treatment, 277 were excluded and 75 patients have been included in the study to date. The mean age of the study population was 65 years (±10.62). The PiMax value was -50 (±19.65) and showed a positive correlation in three of the diaphragm measurements, the mean of the right crural (p=0.01; r=0.335), direct costal (p=0.01; r=0.422) and left costal (p=0.05; r=0.292) measurements. The mean value obtained in the dynamometric assessment, which evaluates overall muscle strength, was 28.25 (±7.76) kgf, correlating positively with MIP (p=0.01; r=0.458) and with the mean values of the right (p=0.01; r=0.367) and left (p=0.05; r=0.234) costal measurements. We found positive correlations between the pulmonary function test and diaphragmatic measurements (p=0.01; r=0.439). The scores obtained in the BFI were very low (mean 0.92) and showed no significant correlation with the other measures found. No correlation was found with length of stay in hospital.

Conclusões

Despite having low to moderate significance, the positive correlation reinforces our initial hypothesis, which relates diaphragmatic size and mass to respiratory muscle strength in patients with lung cancer.

Palavras Chave

Diaphragm; respiratory muscle strength; computed tomography