We found that ideal bloodless visualization of the operative field was obtained in the epinephrine group, comparing that in epinephrine group between before and after use of epinephrine and in two groups prior to cementing. We also found that the use of epinephrine resulted in reducing postoperative hidden blood loss significantly and hemodynamic parameters fluctuated under control in patients receiving epinephrine.
Vasoconstriction effect of epinephrine is complex, and vasoconstriction intensity differs depending on vessel type: arteries, arterioles, precapillary sphincters, capillaries, venules, and veins [19]. It is conceivable that the use of vasoconstrictor epinephrine might predispose to delayed intraoperative bleeding, by temporarily blocking vessels that later start bleeding when the initial vasoconstrictor effect has passed. Though epinephrine’s maximal effect on arterial vasoconstriction may work at 7 to 10 minutes, it takes considerably longer for a new local equilibrium to be obtained with regard to hemoglobin quantity. If optimal visualization and fixation are desired, the ideal time for cement hardening should be the time when local hemoglobin concentration is lowest [20, 21]. Therefore, it is sufficient for cementing of the tibia and femur by preparing two batches of cement 6 to 9 minutes apart, then holding components carefully in place until the cement has completely polymerized. In our study, there was no evidence of any rebound bleeding in the postoperative period in any of our patients, as an indication in the nearly equal volume of intraoperative blood loss that occurred. This finding also suggests that the use of epinephrine does not increase the risk of intraoperative rebound bleeding with good hemostasis for the occurrence of the roughly same volume of intraoperative blood loss.
In our study topical use of epinephrine-soaked gauzes has induced a significant reduction of perioperative hidden blood loss compared with utilization of tourniquet. Epinephrine as a platelet-stimulating agent can cause aggregation of human platelets through alpha-adrenergic mechanisms [8]. It can explain the effectiveness of this procoagulant in decreasing postoperative blood loss because of its hemostatic effect [22].
This method was characterised by the absence of complications and adverse reactions associated with epinephrine. Hemodynamic parameters in our study fluctuated under control in patients receiving epinephrine. Peak changes in HR, MBP, SBP were observed to reached 10 minutes following the beginning of the epinephrine use, and they fell to about original value at 15 minutes from start. Tissue ischemia, infection and skin necrosis were also not detected in the epinephrine group.
This study had several limitations. First, the concentration and technique of epinephrine solution merits deeper considerations and further study. To our knowledge, there is not a single study with outcome measurements that epinephrine is used for hemostasis in the osteotomized sites. A body of previous studies have reported subcutaneous injection of epinephrine solutions in concentrations up to 1:50,000 with good effect in burn and hand surgery [23, 24, 25, 26], and even higher concentration has been safely used in other forms of surgery [27, 28]. We empirically prepared an epinephrine solution at a concentration of 1:125,000 which was higher than that in some orthopaedic surgery, on the basis of consideration that effective drug concentration was longer for cement hardening before it wore off. Meanwhile, the tumescent technique as it applies to suction lipectomy of plastic surgery has been more extensively studied, but these data are not directly applicable to orthopaedic cases as much of the epinephrine is used in bone cut [29, 30]. Hence, we attempted to utilize the technique of epinephrine, soaking not infiltrating, on the osteotomized surfaces, because tumescent or infiltrating technique was abandoned for such adverse effects of epinephrine as delaying wound healing, increasing the risk of infection, and compromising flap survival. Second, the incidence of hemodynamic instability may have been obscured because we merely investigated hemodynamic parameters at 5-minute intervals only for 20 minutes since application of the epinephrine and bone cement may adversely affect hemodynamics. Third, short-, medium-, and long-term outcomes outcome following TKA is needed to evaluate whether the epinephrine procedure will compromise prothesis survival or not. Lastly, we failed to find any differences in the incidence of postoperative complications, this might be due to a relatively small sample size or lack of clinical implication. Further large-scale studies on high-risk patients are needed to assess the association between intra- and postoperative cardiovascular complications and the use of epinephrine.