*3.3.3.2. Inhalational anesthetics*

All inhaled anesthetics have been used in transplanted patients with success. Although halothane is nowadays rarely used, nevertheless it is necessary to mention its potential for hepatotoxicity and direct cardiac depressant effects. Most commonly used volatile anesthetics are isoflurane, sevoflurane, and desflurane. There does not seem to be a significant clinical advantage or disadvantage of one over the others. The choice of inhaled anesthetic can be dictated by the anesthesiologist's preference, experiences, and comfort with the anesthetic [48]. It is probably prudent to avoid prolonged use of N2O because of the potential risk of bone marrow suppression and the potential for altered immunologic response [49].

#### *3.3.3.3. Opioids*

*3.3.2. Airway management*

238 Organ Donation and Transplantation - Current Status and Future Challenges

associated pneumonia [45].

*3.3.3.1. Intravenous anesthetics*

*3.3.3. General anesthesia*

considerations.

Airway management of transplant patients may pose a concern for several reasons. Many patients may have pre-existing diabetes mellitus before transplant or acquire diabetes after transplant. Diabetic patients can develop limitations in joint mobility caused by glycosylation of the connective tissue within their joints [38]. This population is also at increased risk for lymphoproliferative disorders secondary to immunosuppressant drugs, and lymphoproliferative growth may compromise any part of the airway or mediastinum and cause lifethreatening airway obstruction during sedation and anesthesia [41]. Gingival hyperplasia is present at times in patients taking cyclosporine and it may lead to bleeding during airway manipulation. Aspiration risk may be increased in transplanted patients as a result of delayed gastric emptying and gastropathy [32]. These potential problems should all be taken into con-

Oral endotracheal intubation is preferred over nasal intubation because of the potential of infection caused by nasal flora [42]. The use of a laryngeal mask is acceptable (within its indications) [43]. Keep in mind that laryngoscopy and tracheal intubation may not produce a sympathetic response secondary to the loss of cardiac baroreceptor reflexes in heart transplanted patients [44]. Avoid hyperventilation in patients taking cyclosporine and tacrolimus because of a decrease in seizure threshold with these two drugs. Early postoperative extubation is preferred if possible to prevent the development of nosocomial or ventilator-

All inhalational and intravenous anesthetics have been used with success in transplant recipients. The choice of anesthetics and adjunctive drugs should be determined by the type of surgery and condition of the patient. As a general guideline, if hepatic and renal functions are normal, all standard anesthetic medications and adjuncts may be used. Some special considerations for each type of organ transplant are discussed in the section on organ-specific

The selection and administration of intravenous anesthetics should be guided by the patient's hemodynamic status, the drug's cardiovascular effects, and pharmacokinetic properties. Premedication with benzodiazepines is acceptable. Caution should be used in patients with hepatic or renal insufficiency as effects may be prolonged. Also, the dose of barbiturates

Propofol is extensively metabolized by the liver to inactive glucuronic acid metabolites that are excreted by the kidneys. Nevertheless, there seems to be no need for dose adjustments in patients with hepatic or renal failure indicating an extrahepatic route of elimination as well [46]. Caution should be used in patients with cardiovascular compromise as propofol can worsen cardiac contractility, compromise cardiac preload, cause bradycardia, and lower systemic vas-

should be adjusted in patients with hepatic insufficiency to avoid prolonged effects.

cular resistance culminating in diminished cardiac output and mean arterial pressure.

sideration when constructing the anesthetic plan for airway management.

Fentanyl is suitable and safe for short-term use during surgery. However, if used for long duration, the pharmacodynamic effects should be monitored due to accumulation effect. Reduced renal and liver function does not significantly alter the clearance and half-life of sufentanil. Tissue and blood esterases mainly metabolize remifentanil and its metabolite, excreted via kidneys, has low potency [50].

Among opioids used for postoperative pain treatment (morphine, codeine, oxycodone, and tramadol) have to be used with caution. Some of their active metabolites accumulate in renal failure and can mediate CNS and respiratory depression. Transdermal buprenorphine and methadone appear to be safe to use even in patients with renal dysfunction [51].
