Introduction

The evolution of minimally invasive surgery in the last three decades led to better surgical experience, improvements in instrumentation, and application in a wide range of surgical procedures [1]. It has quickly emerged as the new gold standard versus traditional open surgical approaches. The advantages of laparoscopic surgery include reduced tissue trauma, reduced postoperative opioid analgesic requirement, improved postoperative pulmonary function, early recovery, and cost-effectiveness [2].

In laparoscopic surgery, the principles of anesthetic management centers around the interaction of the following elements: (1) intraperitoneal insufflation of carbon dioxide to create a pneumoperitoneum, (2) the systemic effects of carbon dioxide absorption, (3) the extreme changes in patient positioning, and (4) patient-related factors.

The advent of enhanced recovery programs with their goal of accelerating postoperative recovery, reducing the length of stay, and early return to preoperative status by reducing surgical stress response is seen as a complementary approach to minimally invasive surgery [3]. Established ERAS programs integrate several items among which short fasting time, perioperative fluid optimization, multimodal pain management, early mobilization, PONV prophylaxis, and treatment [4] as elements that overlap with the laparoscopic technique.

Physiologic Changes

The greatest impact on cardiovascular, pulmonary, and renal physiology stems from the pneumoperitoneum, the choice of carbon dioxide (CO2) as insufflating gas, and the effects of patient positioning. Carbon dioxide is the preferred gas because it is highly soluble in blood, clears more rapidly, and is not combustible. The increase in intra-abdominal pressure (IAP) from CO2 insufflation exerts mechanical and physiologic effects, while the systemic absorption of CO2 produces hypercarbia and acidosis.

The determinants of cardiac output are systemic venous return and preload. Majority of the venous blood that enters the right atrium comes from the inferior vena cava (IVC). At IAP = 7.5 mm Hg, compression of the splanchnic circulation diverts the blood centrally and an early rise in cardiac output is observed [5]. But as IAP continues to rise beyond 15 mm Hg, mechanical compression of the IVC and blood pooling in the lower extremities results in decreased venous return and a decrease in cardiac output [5].

Neuroendocrine responses and aortic compression results in increases in mean arterial pressure (MAP) and systemic vascular resistance (SVR). Reduction in cardiac output activates the renin-angiotensin system and release of vasopressin resulting in an increase in MAP. Stimulation of the sympathetic nervous system and release of catecholamines mediates the increase in SVR [6]. While vagal stimulation from abdominal distention and insertion of Veress needle may result in bradyarrhythmias and cardiac arrest [7]. Measures to attenuate the vagal response include slower insufflation time, lower IAP, and pharmacologic.

Cephalad displacement of the diaphragm secondary to pneumoperitoneum may impact pulmonary mechanics. Diaphragmatic displacement reduce lung volumes, reduce lung compliance, and increase airway pressures. The resulting decrease in functional residual capacity (FRC) and atelectasis may lead to V/Q mismatch [8].

Hypercarbia and acidosis as the result of CO2 absorption lead to cardiovascular and hemodynamic consequences [9]. Hypercarbia is addressed by increasing minute ventilation to maintain normal end-tidal CO2.

Extreme changes in patient positioning in either a head-up (reverse Trendelenburg) or head-down (Trendelenburg) orientation affect cardiovascular and pulmonary functions. The head-up position leads to venous pooling affecting venous return to the heart. Catecholamines are also elevated in a head-up position, increasing SVR further reducing CO. The head-down position, on the other hand, moves the diaphragm and abdominal contents cephalad, reducing pulmonary compliance and increasing airway pressures. The reverse Trendelenburg favors pulmonary function, while the Trendelenburg favors venous return.

Anesthetic Management

Preoperative Evaluation

Preoperative evaluation and preparation of patients for laparoscopic surgery follow the same guideline equivalent to any surgery. A medical history and physical examination should be performed for all patients. The American Society of Anesthesiologists (ASA) classification aids in stratifying patients based on their physiologic reserves. Keeping in mind the physiologic derangements inherent with laparoscopy, further assessment of the patient’s medical condition may be warranted.

Generally, laparoscopic surgery has a lower cardiovascular risk compared with open techniques. However, an understanding of the physiologic effects of the surgical technique that may increase the perioperative risk in specific patient population is essential. Adequate patient preparation, identification of risks, and anticipation of the hemodynamic and ventilatory effects together with a comprehensive anesthetic plan can mitigate the risk of adverse events and improve postoperative recovery.

Patients with cardiovascular diseases may not tolerate the increases in preload (↑ RAP, PCWP) and afterload (↑ SVR) and a decrease in cardiac output (CO). Those with decreased myocardial reserves may suffer decompensation brought about by further reductions in cardiac output. While the risk of myocardial ischemia in laparoscopic surgery is low, it may be precipitated by increases in myocardial oxygen demand brought about by increases in heart rate (HR), mean arterial pressure (MAP), and systemic vascular resistance (SVR). Mitigating measures include optimization of fluid status preoperatively, appropriate medications including continuing beta-blockers and heart failure medicine, close hemodynamic monitoring intraoperatively, avoidance of hypothermia, keeping the IAP < 15 mm Hg, and adequate pain management [10]. Morbid obesity is associated with comorbidities including diabetes mellitus, hypertension, obstructive sleep apnea, and restrictive lung disease. Pneumoperitoneum during laparoscopy alters the respiratory mechanics more in morbidly obese patients compared with patients of normal weight. Pulmonary compliance is reduced whereas inspiratory resistance is elevated requiring higher minute ventilation to maintain normocarbia [11]. Perioperative management includes avoiding steep head-down position, avoiding early extubation, and in some cases, extubation to CPAP/BIPAP.

Intraoperative Management

General anesthesia with endotracheal intubation and controlled mechanical ventilation is the most common choice of anesthesia technique. Balanced anesthesia employing either inhaled or intravenous anesthetics is chosen based on anesthesiologist’s preference, the pharmacologic profile of the drugs, and the physiologic status of the patient. A total intravenous anesthesia (TIVA) using a propofol-based hypnotic has the added benefit of reducing postoperative nausea and vomiting.

Airway management with a cuffed endotracheal tube prevents aspiration pneumonitis and is still the airway of choice for most laparoscopic surgeries. Carbon dioxide insufflation shifts the diaphragm cephalad which increases airway pressure. This in turn increases the chance of air leaks, inadequate ventilation, and gastric insufflation that potentiates the risk of regurgitation and aspiration.

Several studies have compared the safety, efficacy, and complication risks of supraglottic airway devices (SGA) with endotracheal tubes (ETT). SGAs were found to be clinically useful in laparoscopy [12]. Second-generation SGAs with ventilation tube and gastric access provide higher oropharyngeal leak pressure than first-generation SGAs and reduce the risk of aspiration. These factors make a SGA device a viable option for airway management with the added benefits of attenuated hemodynamic changes compared with laryngoscopy and ETT as well as being well tolerated by patients with fewer incidences of coughing, laryngospasm, sore throat, and hoarseness.

Pneumoperitoneum in laparoscopy may cause derangements of the cardiopulmonary function and a lung-protective ventilation strategy using a combination of tidal volume of 6–8 ml/kg ideal body weight, a fraction of inspired oxygen (FiO2) of 0.5 ml, application of PEEP and recruitment maneuvers help improve lung mechanics and improve hypoxemia [13]. Controlled mechanical ventilation with pressure or volume modes is used to reduce peak inspiratory pressure and manage hypercarbia during laparoscopy.

Neuromuscular blocking agents (NMBA) help facilitate endotracheal intubation, improve surgical conditions by increasing the compliance of the abdomen and allow control of ventilation. The choice is guided by the drug’s pharmacologic profile and anticipated length of surgery. Reversal of NMBAs is by metabolism or pharmacologic (neostigmine and sugammadex). Quantitative evidence of adequate reversal must be confirmed with train-of-four monitor.

Perioperative fluid management is very complex and clinically challenging. Hypervolemia increases the incidence of edema, impairs gut motility, and impairs wound healing. At the other end of the spectrum, hypovolemia may worsen hypotension, lead to oxygen mismatch, organ dysfunction, and lactic acidosis [14]. Static indicators of fluid balance like heart rate, central venous pressure, and urine output are unreliable. However, employing monitors for goal-directed fluid therapy remains controversial in laparoscopic surgery. The decision to use invasive and noninvasive monitors to guide fluid management must be based on the patient’s condition and the extent of surgery.

Monitoring

Placement of routine monitoring equipment follows the basic standards of the ASA and includes pulse oximetry, noninvasive blood pressure monitoring, electrocardiography, temperature, and end-tidal carbon dioxide monitor. Additional monitors are warranted based on the duration of surgery, patient condition, and expected blood loss.

Positioning

Care must be taken to ensure that bony prominences and pressure points are well padded as in any surgery to prevent injury and peripheral nerve damage. Extremes in patient position necessitate the application of non-slip padding and body restraints to secure the patient to the operating table safely. Foot supports are employed in surgeries that require reverse Trendelenburg positions, while shoulder supports placed laterally at the acromioclavicular joint are used for steep Trendelenburg positions. The head is rested on a foam pillow with the neck in a neutral position. Arms are either tucked at the side or abducted to less than 90 on padded arm boards depending on the type of surgery and must be kept in a neutral thumbs-up or supinated position.

Postoperative Management

Pain expectations should be discussed preoperatively. The sources of pain from laparoscopic surgery are both somatic and visceral and the degree of pain depends on the specific surgery but is usually low to moderate. Evidence-based pain management recommends a combination of paracetamol, NSAID or cyclooxygenase-2-specific inhibitor, surgical site local infiltration, and dexamethasone [15]. A procedure-specific, multimodal approach capitalizing on preemptive analgesia and opioid-sparing techniques improve outcomes by providing adequate analgesia and reducing patient discomfort and adverse effects compared with a single opioid technique.

The advent of ultrasound-guided nerve blocks expanded the possibilities for pain management in laparoscopic surgeries. Currently, several techniques (i.e., transversus abdominis plane, paravertebral, and quadratus lumborum blocks) are being explored with promising results.

Postoperative Nausea and Vomiting (PONV)

PONV is one of the most distressing experience for patients after surgery. Although laparoscopy is identified as one risk factor for PONV, the literature is far from robust. Several predictors of risk of PONV in adults have been identified including (1) female gender, (2) history of motion sickness or PONV, (3) non-smoker, and (4) postoperative opioid use [16]. The risk increases with the number of factors present. Current recommendation is a multimodal antiemetic therapy based on the patient’s level of risk using a combination of dexamethasone and 5-HT3 receptor antagonists. Additional antiemetic therapy may be used for very high-risk patients or as a rescue for intractable PONV [17].