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N. Mgbemena1, A. Jones1, P. Saxena2, N. Ang2, S. Senthuran3, A. Leicht4
1James Cook University, Physiotherapy, Townsville, Australia, 2Townsville University Hospital, Cardiothoracic Unit, Townsville, Australia, 3Townsville University Hospital, Intensive Care Unit, Townsville, Australia, 4James Cook University, Sports and Exercise Sciences, Townsville, Australia
Background: Handgrip strength (HGS) and lung function are relevant indicators of future cardiovascular risk and mortality. Previous studies in cardiac populations have reported on the relationship between respiratory muscle strength and HGS at varying stages of disease progression. Evaluation of the effect of cardiac surgery on HGS and lung function, and their association, may aid in timely use of HGS to assess lung function.
Purpose: The aims of the study were to examine the impact of cardiac surgery on:
1) HGS and lung function indices; and
2) the relationship between HGS and lung function in persons with cardiac disease.
1) HGS and lung function indices; and
2) the relationship between HGS and lung function in persons with cardiac disease.
Methods: This study adopted a prospective cohort design and involved adults who were diagnosed with a cardiac disease and undergoing elective cardiac surgery. Handgrip strength was assessed using a JAMAR dynamometer. Three assessments were conducted using the dominant hand and the maximal HGS was reported. Lung function (forced vital capacity [FVC], forced expiratory volume in one second [FEV1] and peak expiratory flow rate [PEFR]) were assessed using a Vitalograph Alpha spirometer. Lung function assessment followed the American Thoracic Society and the European Respiratory Society guidelines. Pre-operative assessments were conducted a day before the surgery, while post-operative assessments were conducted a day before hospital discharge (~7 days after admission). Significant (p<0.05) changes in these variables due to surgery were assessed via Wilcoxon signed-ranks test, while relationships were determined via Spearman correlation analysis.
Results: Forty-two adults (88% males), with a mean age and body mass index of 63.8±11.5 years and 29.6±7.3 kg/m2, respectively, volunteered. The mean pre-operative FEV1 (2.45±0.60 L), FVC (3.25±0.75 L) and PEFR (6.92±2.14 L/s) were significantly higher than their post-operative values (1.36±0.33 L, 1.94±0.44 L, 3.89±1.19 L/s, respectively). No significant difference was found between pre- and post-operative dominant HGS (35.3±13.7 kg and 34.9±11.5 kg, respectively, p=0.77). Significant relationships between pre-operative HGS and FEV1, FVC and PEFR (ρ= 0.63, 0.64 and 0.67, respectively) were identified. Post-operatively, weaker but significant correlations were observed between HGS and FEV1, FVC and PEFR (ρ=0.53, 0.49 and 0.53, respectively).
Conclusion(s): Cardiac surgery significantly reduced lung function without changes in dominant HGS in adults with cardiac diseases. Despite HGS being positively associated with lung function, pre- and post-operatively, HGS may be a less sensitive indicator of operative changes in lung function in persons with cardiac disease. Future research may confirm the suitability of HGS to assess lung function, pre- and post-cardiac surgery.
Implications: Physiotherapists should be aware that reductions in lung function usually last more than one week following cardiac surgery. A simple tool like HGS may be of limited use in monitoring lung function changes associated with cardiac surgery (i.e. before cardiac surgery until hospital discharge).
Funding, acknowledgements: College of Healthcare Sciences, James Cook University
Keywords: Cardiovascular diseases, Upper limb strength, Dynamic lung volumes
Topic: Cardiorespiratory
Did this work require ethics approval? Yes
Institution: Townsville Hospital and Health Service
Committee: Human and Research Ethics Committee
Ethics number: HREC/2019/QTHS/53274
All authors, affiliations and abstracts have been published as submitted.
