*3.3.1. Monitoring*

**3.2. Preoperative assessment and premedication**

236 Organ Donation and Transplantation - Current Status and Future Challenges

for surgery and developing a perioperative anesthetic plan.

put are some of the potential signs and symptoms of infection or rejection.

The following investigations should be available preoperatively.

**a.** Complete blood count (to rule out bone marrow suppression)

**1.** Laboratory parameters:

**c.** Renal function tests **d.** Liver function tests **e.** Coagulation tests

**f.** Biomarkers (i.e. brain natriuretic peptide)

angiography, stress test, spirometry, biopsy)

the upcoming surgical procedure.

**b.** Electrolytes

**2.** Chest radiograph **3.** Electrocardiogram **4.** Echocardiography

The transplant team as well as the attending anesthesiologist and surgeon should have a good coordination during perioperative period, especially if a major surgical procedure is planned. A comprehensive preoperative evaluation by the anesthesiologist should include: evaluation of the graft function, presence of infection, function of other organ systems, the presence of concomitant diseases as well as the preoperative performance or functional status. Adherence to the fundamental principles of preoperative evaluation along with a high level of vigilance is required. Information and medical history should be gathered from the medical records, interview with the patient and/or next of kin or guardian. If medical information is unavailable, attempts should be made to contact the transplant center for pertinent history. Other useful information from the transplant center includes their most recent evaluations and recent data on graft function and general health of the patient. Close communication with the transplant team may be the single most important step in preparing the patient

A thorough review of systems along with a physical examination is essential in this population. Findings such as recent weight gain, edema, dyspnea, sweats, malaise, fever, rashes, abdominal pain, abnormal breath sounds on auscultation, and changes in stool or urine out-

**5.** Miscellaneous: depending on the type of surgery and transplanted organ (i.e. coronary

Each preoperative evaluation and testing should be considered individually based on the target organ system(s) to be evaluated, the patient's medical history, and the inherent risks of

Cardiovascular disease is a major cause of mortality and morbidity among organ transplant recipients, especially in those with chronic kidney disease or previous heart transplant, making Generally, invasive monitoring is not mandatory and anesthesia should be performed using standard European Society of Anesthesiology's monitoring guidelines [40]. The decision to use invasive hemodynamic monitors, placement of central venous access, pulmonary artery catheters, or other procedures such as transesophageal echocardiography should be made on a case-by-case basis. It should be guided by consideration of the patient's comorbidities, hemodynamic stability, the expertise of the anesthesiologist in placing the invasive devices, and by the type of surgery and anesthesia planned. Aseptic technique is of utmost importance to minimize exposure to infectious organisms and bacteremia when attempting any invasive procedures in this population [41].

#### *3.3.2. Airway management*

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 consideration when constructing the anesthetic plan for airway management.

Etomidate does not have the cardiac depressant effect of barbiturates and propofol. Etomidate is metabolized rapidly by hydrolysis within the liver and by plasma esterases and also does not require dosage adjustment in renal or hepatic disease. One unique characteristic of etomidate is its ability to inhibit enzyme necessary for the synthesis of cortisol [47]. This may have clinical significance in patients who already have adrenal suppression as a result

Anesthetic Considerations in Transplant Recipients for Nontransplant Surgery

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239

Ketamine is metabolized via the hepatic cytochrome P-450 system. Therefore, the clinical effects of ketamine are prolonged in the presence of hepatic insufficiency. The usual cardiac stimulating effects caused by central stimulation of the sympathetic system are not present in the denervated heart, but ketamine can still increase systemic vascular tone. Ketamine has neuroexcitatory effects and is known to cause myoclonic activity. It would be wisely to proceed with caution if the katamine is administered in patients who simultaneously take cyclo-

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 mar-

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,

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

The decision to use neuromuscular blockade should be based on the type of surgery and actual need for muscle relaxation during the procedure or the need to optimize intubating conditions. The choice of specific neuromuscular blocking agent should be dictated by length of surgery, underlying medical illnesses (i.e. myasthenia or other neuromuscular disorders), history of malignant hyperthermia, and the functional state of the patient's kidney and liver.

methadone appear to be safe to use even in patients with renal dysfunction [51].

row suppression and the potential for altered immunologic response [49].

of exogenous corticosteroid use.

*3.3.3.2. Inhalational anesthetics*

*3.3.3.3. Opioids*

sporin due to its potential for neurotoxicity.

excreted via kidneys, has low potency [50].

*3.3.3.4. Neuromuscular blockade*

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 ventilatorassociated pneumonia [45].

#### *3.3.3. General anesthesia*

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 considerations.

#### *3.3.3.1. Intravenous anesthetics*

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

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

Etomidate does not have the cardiac depressant effect of barbiturates and propofol. Etomidate is metabolized rapidly by hydrolysis within the liver and by plasma esterases and also does not require dosage adjustment in renal or hepatic disease. One unique characteristic of etomidate is its ability to inhibit enzyme necessary for the synthesis of cortisol [47]. This may have clinical significance in patients who already have adrenal suppression as a result of exogenous corticosteroid use.

Ketamine is metabolized via the hepatic cytochrome P-450 system. Therefore, the clinical effects of ketamine are prolonged in the presence of hepatic insufficiency. The usual cardiac stimulating effects caused by central stimulation of the sympathetic system are not present in the denervated heart, but ketamine can still increase systemic vascular tone. Ketamine has neuroexcitatory effects and is known to cause myoclonic activity. It would be wisely to proceed with caution if the katamine is administered in patients who simultaneously take cyclosporin due to its potential for neurotoxicity.
