In this randomized-controlled trial enrolling patients undergoing selective open heart surgery, application of early and enhanced physiotherapy conferred an advantage in the length of hospital and ICU stay over a conventional physiotherapy strategy. In addition, our study indicated a statistically significant difference in mean post-intervention PO2 between APG and CPG, in favour of active and enhanced physiotherapy. Our study adds to the existing literature as most of the studies dealt with enhanced sessions of physiotherapy after the first post-operative day or ICU discharge, or with enhanced pre-operative physical activity. To our knowledge, this is the first study to compare, in terms of hospitalization length, a conventional physiotherapy strategy with an active physiotherapy, which included enhanced post-operative physical activity along with early mobilization. Of note, no adverse outcomes, such as oxygen desaturation, hypotension, acute coronary events, and arrhythmias were observed during protocols application.
Our results are consistent with those of other studies[8, 9, 13, 14] indicating that early mobilization can decrease hospitalization length. Furthermore, a meta-analysis conducted by Y. Kanejima et al suggested that early mobilization after cardiac surgery might improve physical function at discharge and subsequently prevent prolonged hospital stays[11]. For a patient undergoing open heart surgery, days spent in the ICU, as well as the next three ones, constitute the most critical time of their post-operative phase[15]. Multiple organs, with lungs being of outmost importance, are prone to dysfunction during this period[16].
After open heart surgery, deterioration of functional capacity can be triggered by muscle weakness and proteolysis, induced by reduced mobility. Prolonged inactivity and muscle atrophy are responsible for atelectasis, sensation of fatigue and aspiration pneumonia, which render rehabilitation a ‘highly recommended’ healthcare strategy in post-operative period of invasive cardiac procedures[17–19]. Therefore, the presence of a multi-professional team including physiotherapists in the ICU is proven by several studies to contribute to early patient recovery, reduced mechanical ventilation support need, and ultimately less number hospitalization days, by preventing respiratory complications[20].
On the other hand, some studies on post-operative ICU patients have questioned these outcomes and highlighted the absence of apparent differences between early mobilization and usual care[21, 22] regarding the length of hospitalization. Furthermore, no study has indicated survival benefits for APG patients, and thus a decreased hospitalization length does not seem to be translated into lower rates of all-cause mortality or/and cardiovascular mortality[22]. This is also supported by the fact that the effects of early and active physiotherapy are not reflected on changes in hemodynamic and laboratory indicators[7]. This is in harmony with our results, which only yielded a significant difference in post-operative PO2 and lactate levels between APG and CPG.
Despite not having a clinically significant effect, in terms of hard clinical outcomes and laboratory parameters, active and early physiotherapy could still play a crucial role in reducing healthcare costs and decongesting ICUs. Indeed, another study, with original data deriving from a large registry, also showed that early cardiac rehabilitation was associated with a lower length of ICU and hospital stay, and by such means significantly reduced costs[13].
Our study should be interpreted in the context of its limitations. First of all, our randomized-controlled trial is single centred with a relatively limited number of included patients. Further, we were not capable of thoroughly elucidating our results in a pathophysiological basis, as well as providing clinical explanations about the fact that decreased hospitalization and ICU stay was not translated to altered hemodynamic and laboratory parameters. Moreover, we did not incorporate and analyze any techniques of pre-operative physiotherapy. Finally, our results demonstrated the effect of a combined intervention, which included both early mobilization and enhanced physiotherapy sessions. However, we were not able to separately assess the clinical weight and significance of each intervention on our outcomes. Future clinical studies could test different combinations of physiotherapy and mobilization activities to form the most cost-effective physiotherapy strategy after open heart surgery, which could optimally be based on the clinical parameters of each patient, thereby providing a personalized approach in cardiovascular physiotherapy.