*3.3.3.5. Anticholinesterase drugs*

Most of the cholinesterase inhibitor drugs are eliminated through the kidneys (neostigmine, edrophonium, and pyridostigmine). Caution is advised in renal failure. Several reports described that neostigmine may produce a dose-dependent life-threatening bradycardia in heart transplant recipients, whereas another publication described the safe use of neostigmine [54]. Reversal of neuromuscular block with sugammadex is another possibility, but limited data exist in literature [55].

#### *3.3.4. Regional and neuraxial anesthesia*

The decision to perform a regional or neuraxial anesthetic technique in a previously transplanted patient must be made on an individual basis. We must carefully consider potential benefit and risks of these techniques as well as the anesthetic alternatives when constructing the anesthetic plan in this population. There may be several advantages to choosing a neuraxial or regional technique in this population. Superior analgesia over systemic opioids, especially in patients who may have narcotics tolerance as a result of long-term opioid use, reduced pulmonary complications, and decreased incidence of graft occlusion are just a few of the benefits of regional and neuraxial anesthesia [56]. Clinically relevant doses of bupivacaine and ropivacaine, which are commonly used local anesthetics for neuraxial anesthesia, do not seem to result in toxic levels or increased risk of toxic effects in renal and liver transplant recipients. However, it is important to be prepared for the risk of hypotension because of pre-existing autonomic neuropathy and cardiac denervation in this population. Cautious correction of hypovolemia before epidural or spinal anesthesia may help to attenuate the hypotension. Concurrent hemodynamic monitoring is imperative during the procedure. Direct and indirect-acting adrenergic agonists should be readily available along with emergency airway supplies.

The consideration of spinal or epidural anesthesia is appropriate in this population as long as there is no increased risk for bleeding complications. It is necessary to perform a total blood count to exclude bone marrow suppression, especially thrombocytopenia, and coagulation tests (PT, INR, APTT, and fibrinogen). Peripheral nerve blocks became popular anesthetic option due to hemodynamic stability and better postoperative analgesia. Some studies show no difference in duration of peripheral nerve blocks in patients after transplantation compared to the general surgical population [57, 58]. Nevertheless, large prospective randomized trials are still lacking.

Although the risk of infectious complications is very low, it is important to be highly vigilant when monitoring these patients after a neuraxial anesthesia as the attenuated inflammatory response may diminish the typical signs and symptoms of infection [59]. Again, aseptic technique and a mask should be considered essential when performing these procedures.
