Anemia and iron deficiency treatment
Since preoperative and postoperative anemia are generally related, we refer to the latter in the present section.
Anemia standards and detection
Patients undergoing TKA should meet standard criteria regarding the minimum preoperative Hb [28,29,30].
Otherwise, surgery should be postponed .
Recent guidelines recommend preoperative correction of anemia and iron deficiency in all patients with a Hb < 13 g/dL .
Preoperative assessment of anemic patients should be performed between 30 and 60 days before the procedure, in order to investigate the cause and plan the ideal treatment [24,25,26, 29, 32,33,34].
Pre- and postoperative Hb levels (together with the subsequent need for transfusions) play a role on fast-track TJA postoperative outcomes, Length of Stay (LOS) and patient satisfaction [15, 35].
Preoperative anemia is frequently associated with prolonged LOS, 90-day re-admission and blood transfusions, preventing fast-track TJA to express full value both in THA and TKA procedures [31, 36] (*).
549 fast-track TJA procedures on patients aged ≥ 85 years revealed blood-related issues such as postoperative anemia, blood transfusions, and mobilization to be the most relevant medical cause of more than 4 days LOS (27.3%), where preoperative anemia had no significant impact.
Preoperative anemia was instead one of the main medical causes of readmissions within 90 days, together with suspected but disproved thromboembolic events.
Authors concluded that fast-track TJA aiming at 3 days median LOS and discharge to home is feasible in most patients aged ≥ 85 years, provided attention to pre- and post-operative anemia .
With regard to THA, authors show a weak but significant correlation between post-operative Hb and early functional recovery (6-min walk test) in 65 year-old patients, while they did not find any influence between the former and other functional criteria nor quality of life .
Iron deficiency treatment
Iron-deficiency anemia is the main cause of low Hb [38, 39].
This is why preoperative iron supplementation is highly suggested in orthopedic procedures, alone or together with intraoperative tranexamic acid (TXA) [40, 41]. (*)
Studies report intravenous (IV) iron therapy to be safe and dominate on oral, in particular with patients with malabsorption such as coeliac disease [32, 42, 43].
When using oral supplements for iron storage, a daily dose of 100 mg elemental iron is recommended for 2 to 6 weeks before surgery.
When using IV iron supplementation, requirements can be estimated using the Ganzoni equation .
Studies on 882 unselected fast-track THA/TKA patients confirmed anemia to be prevalent in elderly patients and to be associated with increased transfusion risk and postoperative morbidity.
Iron deficiency is confirmed to be the most common and reversible cause .
Fast-track THA non-anemic patients with iron deficiency were supplemented with oral highly absorbable Sideral® Forte (at least) 4 weeks before surgery. They had a smaller decline in post-operative Hb, shorter hospital stay and reduced blood transfusions, generating a saving of 1763.25 € per patient.
Therefore, preoperative sucrosomial iron® is a cost-effective solution for fast-track THA surgery . (*)
Blood thinners (antiplatelet, anticoagulant, antithrombotic agents)
These drugs have a key role in preventing cardiac and vascular events .
To normalize bleeding, they are usually stopped a few days before surgery ...
... But patients at high cardiovascular risk should not stop aspirin in the perioperative period .
Given that cardiovascular disease is common in patients planning to undergo to TKA, both the continuation and the discontinuation of antiplatelet therapy can be associated with major risks, depending on patient characteristics, severity of the procedure and estimated time of immobilization [8, 49, 50].
The management of these medications in the perioperative setting should be adapted to the single patient according to cardiologist, orthopedic surgeon, and anesthesiologist .
Preoperative use of anticoagulant agents needs important evaluations in fast-track TJA too [51, 52]. (*)
A study on the incidence of stroke within 30-days after 24.682 fast-track TJA found preoperative use of anticoagulant treatment to be the most important risk factor, together with age ≥ 85. Anemia was also included, but not significant.
It is therefore important to check for the use of preoperative anticoagulants, and anemia, to avoid cardiovascular perioperative events in elderly patients . (*)
Transfusion protocol agreement
Although transfusion is a postoperative intervention, establishing the trigger must be done before surgery.
Reasons to variate transfusion practice in orthopedic surgery are not well understood.
In case of elective surgery, the need for allogenic transfusion was said to predictable in 97.4% of the cases, according to (i) preoperative anemia, (ii) perioperative blood loss, (iii) transfusion trigger .
A survey on clinicians and hospitals in the UK showed transfusion triggers after TJA to variate between 6 to 11 g/dL, calling for shared evidence-based guidelines to improve practice and avoid waste .
This is consistent with results from a previous international survey, according to which transfusion triggers vary significantly among different clinicians, hospitals and countries .
Systematic review on transfusion drivers in orthopedic surgery shows low Hb and old age to be the main predictors for the need of transfusion, followed by surgical complexity, low body weight, additional comorbidities (rheumatoid arthritis, history of anemia, diabetes, cardiovascular disease, renal failure, or metastasis), and female sex .
Studies on restrictive triggers in major orthopedic patients show transfusion rate and deep wound infections to be respectively reduced from 34 to 17%, and from 2.6 to 1.5% .
This is confirmed by a prospective study on unilateral knee arthroplasty (UKA), which adopted a postoperative trigger < 8.5 g/dL (or greater in case of a symptomatic patient): transfusion rates were reduced from 31 to 11.9%, blood waste from 60 to 1%, with no adverse outcomes .
Current evidence confirms that a restrictive trigger (Hb < 8 g/dL) is safe and cheaper3
... which is supported by the National Institute for Health and Clinical Excellence even more restrictive recommendations .
A study on fast-track TJA predictors of LOS and patient satisfaction found:
The need for blood transfusion to be the main predictor of a longer stay (> 3 days)
Blood transfusion to occur in 22% and 12% of THA and TKA respectively, although it does not compromise a high satisfaction rank (9.4 and 9.3 up to 10)
Transfusions were administered when postoperative hematocrit level (at the first day) was 25% less than preoperative.
Transfusions were associated with age, lack of mobility during the first day after surgery, co-morbidities, low Hb and increased ASA score .
The need for blood transfusion is a predictor that produces significant value in accelerated pathways such as fast-track surgery, since they provide caregivers with useful information to plan for treatments and beds.
Waiting for blood transfusion is indeed one of the main reasons to delay discharge [61, 62]. (*)
EPO reduces post-operative transfusions  both in THA and TKA [64,65,66,67], even in rheumatoid arthritis patients , but it is associated with adverse events such as deep venous thrombosis (DVT), pulmonary embolism (PE), fever, hypokalemia, urinary tract infection, nausea, hypoxia, and vomiting in up to 5% of the population [68,69,70].
Moreover, it is unclear whether benefits are not offset by costs .
Therefore, EPO is suggested in exceptional conditions such as patients with strong anemia who (i) cannot receive blood because of red cell antibodies, (ii) refuse donation because of religious beliefs [18, 60, 72].
The use of TXA has almost eliminated the need for other blood conservation strategies [73, 74], and is therefore a valuable innovation to be applied under a fast-track pathway .
Preoperative autologous blood donation (PAD)
Major concerns regarding PAD are related to handling errors, blood infection, and poor cost-effectiveness [76,77,78,79].
The overall benefits of PAD in primary joint arthroplasty can outweigh the harms in alloimmune and rare blood types patients [8, 80].
The use of TXA has almost eliminated the need for other blood conservation strategies [73, 74], included PAD, which makes it a valuable innovation under a fast-track pathway.