Antibiotic prophylaxis suitable for clean surgery (Altemeier class 1) must be administered when a resection of a benign tumor, which has developed within a healthy or a diseased liver tissue, is scheduled. Intraoperative antibiotics prevent translocation of intestinal enterobacteria to the systemic circulation due to long operating time and large areas of postsurgery dead spaces and devitalized tissue [3, 4]. Usually, an intravenous first-generation cephalosporin before induction of general anesthesia and during prolonged surgical time is recommended [3]; if penicillin allergy is reported, the administration of macrolide or quinolone drugs is recommended. In case of biliary compression or obstruction, considered as a potential source of sepsis even without signs of clinical infection, piperacillin combined with an aminoglycoside or with a fluoroquinolone is suggested [4, 5].

Usual monitoring consists of standard noninvasive monitors and selected invasive monitors that are able to detect alterations of physiological parameters that may be explicable by the surgical procedure in order to prevent complications. Intraoperative monitoring should be adapted to the preoperative condition of the patient, the extent, and the technique of the liver resection.

Routine monitoring includes arterial pressure, electrocardiography (EKG), pulse oximetry, and capnometry.

An arterial catheter is usually inserted for invasive monitoring of blood pressure and for easy access to blood samples to check and eventually correct blood glucose values, plasma electrolytes, and potential metabolic acidosis.

The intraoperative placement of a nasogastric tube may prevent gastric distension during surgery, but it is usually removed after surgery according to ERAS guidelines.

In case of potential massive blood loss, a large-bore venous line may be used (14G). Central venous catheter (CVC) positioning is not always necessary; it provides an infusion line useful for vasopressor administration, and it allows to measure the value of the central venous pressure (CVP) to guide intravascular volume replacement and to assess hemodynamic changes when a large liver resection is planned.

During liver resection, there are some predictable variations of the CVP induced by surgical maneuver: the pressure of surgical refractors during laparotomic resection and the increased intra-abdominal pressure during laparoscopic procedure. Moreover, liver mobilization, twisting the vena cava, and clamping of the liver vessels through Pringle’s maneuver reduce the venous return of blood to the right heart and therefore decrease the CVP [6, 7].

Hence, it could be better to monitor the trend of this value or simply use other devices.

Indication for pulmonary artery catheterization is reserved for patients with known preoperative left ventricular dysfunction, preoperative sepsis, or intricate circulatory impairment [8].

Nowadays, it is possible to monitor volemia and its hemodynamic changes, thus guiding infusion with a goal-directed therapy, through new minimally invasive devices which may be considered safe and reliable. This hemodynamic monitoring includes the esophageal ecodoppler monitor, the stroke volume variation, and the transesophageal echocardiography. They can provide information regarding volemia as well as cardiac performance, guiding both infusion of crystalloid or colloid and administration of vasopressors.

Liver resections are usually performed under general anesthesia with tracheal intubation and controlled mechanical ventilation.

In case of patients with ascites or other causes of increased intra-abdominal pressure, a rapid sequence induction with cricoid pressure must be performed to avoid the risk of inhalation of gastric contents.

Paralysis may be obtained with a muscle relaxant.

Cisatracurium and atracurium are the nondepolarizing muscle relaxant of choice in patients with liver disease as they have no hepatic metabolic pathway but they are hydrolyzed by Hofman elimination. Moreover, cisatracurium is hemodynamically stable due to its scarce release of histamine [9].

Fentanyl and sufentanil pharmacokinetics are unlikely to be alternated even if liver impairment exists before surgery; liver function is not involved in remifentanil elimination [10] though the hyperanalgesia inducted by this opioid must be considered.

Anesthesia may be maintained with standard methods as well; it is usually granted with an halogenated volatile agent in air-oxygen mixture: isoflurane, sevoflurane, or desflurane at 0.2–1.0 age-adjusted minimum alveolar concentration (MAC) equivalents, titrated to hemodynamics.

Most commonly isoflurane and sevoflurane are used. Isoflurane has mild cardiodepressive effects but maintains hepatic oxygen supply, due to vasodilatation, and accordingly increases splanchnic blood flow [11]. Sevoflurane seems to decrease portal vein blood flow but increases hepatic artery blood flow [10]. In addition, Beck-Schimmer et al., in a randomized controlled trial on patients undergoing liver surgery [12], showed that ischemic preconditioning with sevoflurane before inflow occlusion limited postoperative liver injury.

However, there is no evidence that any one anesthetic agent should be preferred to another for the maintenance of anesthesia in elective liver resection [13].

During all the intraoperative period, patients must be warmed using more than one method. Warming is an important topic since it is involved in homeostasis of coagulation and clotting, thus reducing risk of hemorrhage; moreover, it is well known that hypothermia increases both the risk of surgical site infection and the time of recovery [14].

Usually it is applied on patient’s upper chest and arms as a forced-air warming blanket; thermoreflectant units may be used on legs and head to prevent heating leakage. IV fluids should be warm or actively warmed through dedicated systems.

Temperature must be monitored both in the operative room and in the recovery room in order to maintain a value of Tcore >36 °C [14].

Postoperative nausea and vomit prophylaxis is usually performed, administering ondansetron at least 40 min before the end of surgery.

Oxygen saturation measured using pulse oximetry may give early indication of impaired pulmonary gas exchange or inadequate function. Although it is unusual in patients to be submitted to hepatic surgery for benign lesions, approximately one-third of patients with cirrhosis or noncirrhotic portal hypertension has varied degrees of hepatopulmonary syndrome.

Hepatopulmonary syndrome is defined by the presence of hepatic dysfunction or portal hypertension and an elevated alveolar-arterial oxygen gradient. Hypoxemia in these patients is due to ventilation/perfusion mismatching, characterized by an increase in pulmonary perfusion secondary to capillary distension and accelerated transpulmonary blood flow [15]. Initially, hypoxemia can be treated by supplementation in inspired oxygen fraction and in ventilation.

Mechanical ventilation may be volumetric or pressumetric. A recent prospective randomized study on protective ventilation conducted by Pelosi and colleagues [16] showed that lower tidal volumes (7 ml/kg) with positive end-expiratory pressure (PEEP) and recruitment maneuvers improve pulmonary function and decrease postoperative pulmonary complications compared with high tidal volumes (9 ml/kg) and zero-positive end-expiratory pressure (ZEEP).