Chapter 51: Anesthesia for Gastrointestinal Surgery

KEY POINTS

1. Widespread introduction of minimally invasive surgical techniques and perioperative care pathways for patients undergoing gastrointestinal (GI) surgery has reduced complications and accelerated recovery.

2. Laparoscopy entails the installation of gas (usually CO₂) into the peritoneal cavity to institute a pneumoperitoneum. A pneumoperitoneum has several clinical effects that can complicate anesthetic and hemodynamic management. It is associated with increases in systemic and pulmonary vascular resistances (SVR and PVR) and a decrease in cardiac output.

3. Patients define recovery as: “the absence of symptoms and return of their ability to perform activities as they could prior to surgery.” Within a traditional perioperative care pathway this rehabilitation period can last many months.

4. Enhanced recovery pathways (ERPs) are evidence-based multidisciplinary protocols designed to standardize medical care, accelerate the functional recovery of surgical patients, and lower healthcare costs. The anesthesiologist, as a perioperative physician, plays a vital role in facilitating adoption and implementation of ERPs.

5. ERPs include specific management of intraoperative fluid management in order to maintain central euvolemia while minimizing salt and water excess. Excessive fluid administration during elective colonic resection is associated with delayed recovery of gastrointestinal function, increased complication rate, and extended hospital stay. A major goal of an ERP is to mobilize and feed on the day of surgery, and thus avoid periods of physical inactivity and starvation, which induce a loss of muscle mass and deconditioning that correlates with complications.

6. Goal-directed therapy (GDT) is a term that is used to refer to individualized fluid management incorporating fluid challenges to optimize flow-based parameters such as stroke volume (SV). Multiple studies have shown a reduction in complications with GDT in high-risk abdominal surgery although the benefit of GDT within an ERP is not proven.

7. The delivery of an effective multimodal pain management strategy is an important component of any ERP. Opioids should be avoided as much as possible as they lead to a host of undesirable side effects including, but not limited to, delayed return of gastrointestinal function, nausea and vomiting, somnolence, and decreased appetite. Multi-modal analgesia typically consists of regular acetaminophen and nonsteroidal anti-inflammatory drugs (NSAIDs; unless contraindicated) throughout the patient’s perioperative course from the preoperative holding area until after discharge, given orally whenever possible. Other drugs that can be used as part of a multimodal regimen include gabapentinoids, intravenous and transdermal lidocaine, N-nitrosodimethylamine (NDMA) receptor antagonists (ketamine, magnesium), glucocorticoids, and α_{2 -}adrenergic receptor agonists (clonidine, dexmedetominidine).

8. Thoracic epidural analgesia (TEA) is considered the gold standard for major open abdominal surgery within ERPs, unless contraindicated. However, TEA has the potential to cause harm such as hypotension, and poor analgesia if not working well. The effectiveness of TEA is likely to be greater if managed by a dedicated acute pain service.

9. There is no gold standard regional anesthesia technique for laparoscopic surgery. Techniques that are used include TEA, intrathecal (spinal) analgesia, paravertebral blocks, transversus abdominal plane (TAP) blocks, and local anesthesia in the wound: all combined with ...