Does Anesthetic Choice Affect Surgical and Recovery Times?

INTRODUCTION

One of the most common concerns of physicians and patients is the potential adverse effects of anesthesia on recovery times after surgical procedures. Although mortality rates for anesthesia have continued to decrease over the years, postoperative complications continue to pose a risk for patients and providers. Scientific literature shows continued interest in anesthetic techniques shown to decrease poor outcomes. Traditionally an investigation of these techniques would require an in-depth analysis of the effects of various anesthetic agents. Over the past decade, however, the collaboration of anesthesiologists with surgeons and others has provided a substantial body of literature relating to multimodal perioperative management to improve care.

TRADITIONAL MEASUREMENTS OF OUTCOMES

Traditionally, measurements of the effectiveness of anesthetics have focused on “surrogate” outcomes. These include time to eye-opening; early recovery (time to obey commands); time to home discharge; incidences of postoperative complications, such as shivering; drowsiness; and postoperative nausea and vomiting (PONV). Studies have shown that there were essentially minor differences between the various anesthetic agents that are now commonly used, with the notable exception of decreased nausea and vomiting with the use of propofol. When one considers “true” outcomes after anesthesia, the studies look at measures such as discharge time, admission and readmission rates, return to work, and patient satisfaction with anesthesia. Again, the various anesthetic agents have essentially similar profiles regarding these outcomes. Patient satisfaction with anesthesia is a very focused outcome, which studies have usually shown to be about 97%. This outcome does not seem to have any relation to the type of anesthesia used, with one study suggesting that it was the efficient organization of an ambulatory surgical unit that plays a vital role in this measure. Although these approaches have led to significant insights into the management of specific postoperative outcomes, they have not led to a holistic management approach. With the introduction of the concept of enhanced recovery after surgery (ERAS), anesthesiologists now have an improved framework in which to judge their anesthetic management.

PATHOPHYSIOLOGIC BASIS FOR ERAS

Dr. Henrik Kehlet first proposed ERAS as the concept of a multimodal approach to control postoperative pathophysiology and rehabilitation. Patients rarely die on the operating table but instead die from the surgery’s pathophysiologic response and complications. This finding has led to a treatise revolving around the unified practice of surgery and anesthesia in preparing and supporting a patient through the perioperative period. In 2001, a study group was formed to examine the process of change from traditional to best practice in multimodal surgical care. The group’s stated goal was to examine ways to improve perioperative care and enhance postoperative recovery by implementing evidence-based practice, audit, education, and research. This ERAS group reevaluated practices during the perioperative process to shorten hospital stays, reduce complications, reduce readmissions, and improve patient satisfaction. With success in their studies, the ERAS Society was founded in 2010 with representatives from surgical, anesthesiology, and nursing groups.

The pathophysiologic basis for ERAS revolves around preventing or minimizing the stress induced on the human body by surgery. This response includes all elements associated with surgery, including anxiety, fasting, hemorrhage, hypothermia, fluid shifts, pain, hypoxia, bed rest, ileus, and cognitive imbalance. These threats can compound and lead to patient morbidity. Studies have shown that managing these stressors minimizes the potential risk for organ dysfunction, which could lead to complications and decreased long-term survival. The key elements of ERAS pathways for anesthesia are perioperative rehabilitation; perioperative nutrition; carbohydrate loading; prevention and treatment of PONV; aggressive intraoperative warming; and antibiotic administration, the use of opioid-sparing anesthesia techniques, fluid management, and lung-protective ventilation strategies.

PERIOPERATIVE ERAS ELEMENTS

Ideally, patients should be maximally prepared for surgery. This includes a completed risk assessment, optimization of preexisting medical conditions, and education. A thorough review and evaluation of the patient’s condition must be undertaken before any surgery. This becomes especially important in ERAS surgery, where care should be taken to select patients that need further evaluation and optimization before being assigned to a perioperative care pathway. A study in the Annals of Surgery reviewed data on 105,951 patients undergoing a variety of different surgeries. This study revealed that if patients had a major complication within 30 days of surgery, they had reduced median survival by 69% at 8 years. Studies have shown that patients with poor physical conditioning have a greater incidence of postoperative morbidity and mortality. It is for this reason that a risk assessment must be completed on all patients. Anesthesiologists are familiar with the American Society of Anesthesiologists (ASA) Physical Status (PS) Classification model. This provides anesthesiologists with an idea of the relative risk for a patient undergoing anesthesia. For years this has been used as a surrogate measure by surgeons. Nowadays, surgical risk assessment can be performed using calculators, such as the American College of Surgery National Surgical Quality Improvement Program (NSQIP).

Optimization of preexisting conditions and pharmacologic requirements continues to be a requirement before any surgery. Ideally, a patient’s physiologic reserve needs to be improved before the perioperative period. In modern medicine, prehabilitation of the patient before surgery appears to improve outcomes, but this concept’s practical application is challenging because of surgical scheduling.

The education of both patients and caregivers should be initiated before surgery. A knowledgeable team, inclusive of the patient, can make the application of ERAS principles across the care teams more cohesive. This, in turn, will allow the process to proceed uniformly and relieve the patient’s anxiety. Studies demonstrate that patient expectations play a clear role in determining the postoperative outcome. Information about the process of care should be delivered to caregivers and patients.