“…Moreover, in patients whose post-surgery pain is not properly controlled, cardiac failure is increased three times and the rate of infection is increased five times (Soltani et al., 2017). In addition, untreated pain has adverse physiologic and metabolic effects on vital signs and on the immune, pulmonary, cardiovascular, gastrointestinal, and endocrine systems; it also causes distress and suffering for patients, respiratory distress and declined chest expansion, respiratory dysfunction with hypoxia, and increased sympathetic response, together with myocardial ischemia, increased general stress with an increased heart rate, increased cardiac output, and vessel contraction (Dave, 2016).…”