Enhanced Recovery After Surgery Trends in Adult Spine Surgery: A Systematic Review

Patient Education

Educating the patient prior to surgery is a common component of the ERAS preoperative pathway. Although traditional care pathways may include patient education, they are less structured and standardized in implementation. ERAS patient education for spine surgery includes setting realistic goals and expectations for surgery and recovery,^{21–25,28,30,32–34,36,37,39,40} recommending preoperative nutrition and exercise regimens,²⁵ educating about the ERAS components,^23,34,39 and educating about pain management (perioperative and postoperative MMA, how to grade pain, how pain scores translate to analgesia selection, etc.).^{25,33,34,37–39} In addition to providing videos, handouts, and oral presentations to educate patients, some research groups also implemented a helpline and enlisted 24-hour on-call nurses to aid in preoperative patient education.^23,28,33 Many of the ERAS patient education guidelines share similar features but differed in their degree of detail and implementation.

Despite the frequent inclusion of patient education in ERAS protocols, there is a lack of evidence regarding its impact on patient outcomes. Previously, patient education was not found to significantly improve surgical outcomes or reduce patient anxiety; in a review of preoperative education for hip and knee replacement procedures, McDonald et al⁴¹ concluded that patient education may only benefit patients with preexisting depression, anxiety, or unrealistic expectations. It is thus unclear whether standardized patient education guidelines are necessary in most cases. However, some research groups^34,39 have based their rationale for including ERAS patient education on the McDonald et al⁴¹ review article, claiming that educating patients can enhance postoperative and recovery outcomes.

Comorbidity Assessment and Health Optimization

Patients who undergo elective spine surgery often have other comorbidities, such as diabetes or cardiovascular disease, especially as the population of elderly patients desiring spine surgery continues to increase. Considering the physiologic stress placed on the body by surgery, several institutions opted to evaluate and address patient comorbidities as part of their preoperative ERAS protocol (Table 2). In this way, the patient's health may be optimized prior to surgery to reduce the risk of postoperative complications.⁴⁰

Several ERAS spine protocols required screening for risk factors like diabetes, cardiovascular disease, obesity (body mass index), smoking status, narcotic/alcohol use, anemia, nutritional status, and obstructive sleep apnea. The American Society of Anesthesiologists classification, which indicates the severity of a patient's comorbidities, was also calculated in some protocols.^20,21,36,40 For patients who presented with comorbidities or who did not meet the health criteria, one of several forms of intervention were taken. Some studies built in exclusion criteria for surgery, such as cutoff body mass index and American Society of Anesthesiologists classification values^20,31; some delayed the procedure and/or offered counseling and medical services for diabetes, weight loss/nutrition, exercise, smoking cessation, obstructive sleep apnea, and narcotics/alcohol use^{21,22,28,31,37,40}; and some developed their own “pre-habilitation” exercise regimens for patients to follow.^22,27

Although it is unclear how health assessment and optimization independently contributed to patient outcomes, previous studies in other surgical specialties have shown a link between preoperative comorbidities and postoperative outcomes. In a study of geriatric patients undergoing noncardiac surgery, Leung and Dzankic⁴² showed that patients with neurologic or cardiovascular comorbidities were at higher risk of adverse postoperative events. Oresanya et al⁴³ similarly reported a correlation between cognitive impairment, malnutrition, and frailty with adverse outcomes in geriatric surgical patients.⁴³

“Preemptive” Analgesia

The consumption of nonopioid analgesics prior to induction has been correlated independently with decreased pain levels and reduced opioid consumption (known as an opioid sparing effect) after spine surgery.^45,46 Notably, Kim et al⁴⁶ administered a cocktail of 200 mg of celecoxib, 75 mg of pregabalin, 500 mg of acetaminophen, and 10 mg of extended-release oxycodone—as opposed to conventional morphine for the control group—at least 1 hour prior to surgery. Patients who received this preemptive cocktail demonstrated lower visual analog scale (VAS) and Oswestry Disability Index values at nearly all POD time points measured. Furthermore, there were no significant differences in postoperative complication rates.⁴⁶

For spine ERAS protocols, the combination of acetaminophen PO (usually 1000 mg) and gabapentin PO (usually 300 mg) was commonly administered to patients on the morning of surgery,^{25,30,32,36–39} and also the night before surgery.^30,32 Other oral analgesics, like 200 mg of celecoxib³⁴ and 150 or 75 mg of pregabalin,^25,34 were also administered. These analgesic options have been shown to effectively reduce pain^45–47 and opioid consumption⁴⁵ following spine surgery. For the acetaminophen and gabapentin combination specifically, Syal et al⁴⁸ previously reported improved postoperative pain scores in patients who underwent open cholecystectomy, which suggests that this combination of premedication may be effective for other types of surgeries.

Indeed, some spine ERAS studies that implemented preemptive analgesia showed decreased use of postoperative patient-controlled analgesia (PCA) and/or opioid consumption, even as their associated surgical procedures varied greatly.^25,27,36,38 These studies did not indicate reduced pain scores, however.^25,27 In fact, Soffin et al³⁸ implemented the acetaminophen-gabapentin combination yet found neither reduced pain scores nor reduced opioid consumption postoperatively—even with the contribution of other ERAS elements. It seems that more research regarding the effects of preemptive analgesia on postoperative outcomes in spine surgery is required.

Intraoperative MMA

The use of intraoperative medications to minimize postoperative pain is another integral component of optimizing patient outcomes. A variety of intraoperative MMA regimens have been implemented in the spine ERAS protocols (Table 3). For example, for spinal metastatic tumor resection surgeries, Grasu et al²⁵ implemented infusions of propofol, dexmedetomidine, ketamine, and lidocaine, along with a single upfront IV dose of methadone (0.1–0.2 mg/kg) in opioid-tolerant patients. In contrast, Ali et al²⁷ administrated intraoperative NSAIDs, dexamethasone, and local bupivacaine in addition to conventional opioids for various elective spine procedures.²⁷ Other common analgesic medications were used intraoperatively, like acetaminophen^30,32 and other local analgesics.^{24,31,34,39,40} Particular attention was given to modulating the choice of anesthetics; several studies avoided using general anesthesia and long-acting agents. When general anesthesia was used, propofol appeared to be preferred among the ERAS studies.^{25,30,32,38–40}

Moreover, numerous non-ERAS studies have investigated whether a multimodal approach to pain management can limit postoperative pain and opioid use in spine surgery.^49–52 Loftus et al⁴⁹ studied the effect of intraoperative ketamine (initial bolus of 0.5 mg/kg, followed by infusion at 10 μg/kg/min). In this study, the treatment group received a loading dose of ketamine prior to induction and a continuous drip during surgery.⁴⁹ Patients in this treatment group required 24% less intraoperative opiate medication; these patients also consumed 37% less morphine in the 48 hours following surgery compared with the control group.⁴⁹ Moreover, at the 6-week follow-up, the treatment group patients reported the same reduction in pain despite a 71% reduction in opioid consumption.⁴⁹ Tunali et al⁵⁰ similarly studied the efficacy of IV paracetamol (1 g) and dexketoprofen (50 mg) on postoperative pain and morphine consumption following lumbar disc surgery. Here, Tunali and colleagues⁵⁰ measured VAS scores and total morphine consumption in the first 24 hours after surgery, respectively. The authors reported that pain scores were significantly reduced with dexketoprofen administration but not with paracetamol.⁵⁰ However, there was no difference in morphine consumption with either medication when compared to placebo.⁵⁰ Later, in a randomized controlled study, Nielsen et al⁵¹ investigated the administration of preoperative dexamethasone (16 mg) combined with intraoperative paracetamol, reporting that although pain scores were significantly reduced in the first 24 hours following surgery, this difference dissipated at the 3-month follow-up. Notably, there was a 6.5% incidence of postoperative infection in the dexamethasone treatment group, which limits the benefit that this medication can have on patients.⁵¹ Finally, Garg et al⁵² administered ketamine (bolus 0.25 mg/kg followed by 10 mg/kg/hr infusion) or dexmedetomidine (0.5 mg/kg followed by 0.3 mg/kg/hr infusion) to patients during induction for various elective spine procedures.⁵² The authors reported that patients who received ketamine and dexmedetomidine experienced greater pain-free periods during the first 48 hours after surgery, as well as reduced consumption of rescue pain medication, compared with the control group.⁵²

Minimally Invasive Surgery

The MIS technique is being adopted rapidly in spine surgery and involves minimizing intraoperative soft tissue disruption and blood loss.⁵³ The inclusion of MIS in ERAS pathways is aimed at improving cost-effectiveness and enhancing postoperative recovery. Prior research comparing MIS TLIF/PLIF with the traditional open approach suggests that MIS results in reduced hospital costs,^26,53,54 LOS,^53,55,56 and blood loss.^53,56 However, the benefits of MIS on overall clinical outcomes remain controversial,^3,55 with some studies achieving reduced short-term readmission and complication rates,⁵⁶ and others finding no additional short- or long-term clinical benefits compared with the open surgical approach.^53–55 From current evidence, it seems that MIS procedures are more cost-effective and yield comparable clinical outcomes.

The MIS approach was adopted by several ERAS protocols for lumbar fusion or decompression procedures (Table 3). Grasu et al²⁵ also employed MIS technique for an ERAS metastatic tumor resection protocol. Brusko et al²⁹ employed MIS technique for 1- to 3-level posterior-only lumbar fusion surgeries. Debono et al²³ and Soffin et al³⁸ pursued a protocol for lumbar microdiscectomy.^23,38 In ERAS studies, MIS technique involved a small incision, tubular working channels and endoscopy, percutaneous screw insertion, expandable cage implants,^{24,26,38–40} and robotic and microscope guidance.^38–40

Thus far, the use of MIS in spine ERAS studies has been associated with various positive outcomes, especially for MIS TLIF procedures (Table 1). For example, Wang et al²⁶ reported reduced intraoperative time, LOS, complication rate, and acute care costs, and Feng et al³⁴ reported reduced LOS and mean costs but no difference in intraoperative time or complication and readmission rates. Interestingly, Wang et al²⁶ were able to enhance the cost-effectiveness of MIS TLIF using only 6 perioperative ERAS interventions, 3 of which pertained to an MIS surgical approach (working channel endoscope, expandable cage, small-caliber percutaneous screws). Results by Wang and colleagues²⁶ suggest that the use of MIS may account significantly for the benefits of ERAS pathways.

Maintaining Homeostasis (Blood Loss, Fluids, Temperature)

Managing body homeostasis during surgery helps to reduce postoperative complications and enhance the return of normal bodily functions.² In particular, the management of blood loss, normovolemia, and normothermia has emerged as a popular inclusion in ERAS pathways. Minimizing blood loss in turn can reduce the risk of hypotension, end-organ damage, and coagulopathy, as well as complications related to blood transfusions. Maintaining normovolemia for patients undergoing major spine surgery has been associated with reduced blood loss and transfusion, improved postoperative respiratory function, faster return of bowel function, and reduced LOS.⁵⁷ Conversely, overhydration and underhydration of the patient intraoperatively have been associated with increased complications.² Monitoring and maintaining body temperature during surgery is similarly important for postoperative recovery, because hypothermia increases the risk of wound infection after spine surgery.⁵⁸

For blood loss management, tranexamic acid—which has been reported to decrease bleeding and transfusions during spine surgery⁵⁹—was administered intraoperatively in several spine ERAS pathways (Table 3). In the studies, tranexamic acid was given as an IV bolus before skin incision and as an infusion through the procedure. Bolus dosage varied (2 g, 20 mg/kg, 0.5 g/hr, or 1 g prior to incision and another 1 g over 8 hours)^21,30,31 because optimal dosing for surgery has not yet been determined. Other methods of minimizing blood loss include minimal use of blood transfusions and preoperative arterial embolization for high-risk bleeding tumors,²⁵ making available autologous cell-salvage transfusions,⁴⁰ and administering oral iron supplements or iron transfusions for anemic patients prior to surgery.³⁴ Consequently, Feng et al³⁴ and Dagal et al³² were able to significantly reduce intraoperative blood loss for MIS TLIF and various major spine procedures, respectively. Chakravarthy et al³¹ also reported decreased blood transfusions for ERAS patients undergoing major and complex spine surgeries. Other studies that administered tranexamic acid did not report a comparative blood loss measure.²⁵

For maintaining normovolemia intraoperatively, a combination of hemodynamic monitoring and as-needed fluid replacement therapy was used (Table 3). This type of intervention is known as goal-directed fluid therapy (GDFT).⁶⁰ According to the American Society for Enhanced Recovery, the goal of GDFT is to achieve a net “zero-fluid balance” (euvolemia) perioperatively in order to reduce postoperative complications and LOS.⁶⁰ Thiele et al⁶⁰ recommend the use of isotonic IV crystalloids (salt solution with small molecules) for fluid replacement, which was employed by Chakravarthy et al.³¹ Other ERAS protocols that implemented GDFT did not specify their method of fluid therapy. Ljungqvist² further recommends the use of a combination of colloids (which contain larger molecules) and crystalloids, and warns against the use of 0.9% saline, which can cause prolonged postoperative fluid retention. Of note, both Thiele et al⁶⁰ and Ljungqvist² formulated their guidelines based on data from ERAS colorectal surgery. But there seems to be no consensus for optimal GDFT for spine surgery.^2,60

Finally, normothermia was monitored and maintained intraoperatively in a number of studies (Table 3). Optimal body temperature was set between 36°C and 37°C and was monitored throughout the procedure. Various methods of body warming were used intraoperatively, like hot air blankets, fluid warmers, and a convective warming device.

Deep Venous Thrombosis, Infection, and Postoperative Nausea and Vomiting Prophylaxis

Deep venous thrombosis, infection, and postoperative nausea and vomiting (PONV) are postoperative complications that can significantly hinder patient recovery. To avoid such complications, prophylactic measures have been incorporated into spine ERAS protocols (Table 3). For antithrombotic prophylaxis, compression stockings/devices and low–molecular weight heparin were used intraoperatively.^24,35,40 Postoperative thromboprophylaxis has been implemented as well, also in the form of compression devices, heparin, and early and frequent ambulation.^31,35 Notably, Sivaganesan et al³⁵ reserved the use of chemoprophylaxis for uncommon cases, namely for cases involving combined anterior and posterior approach, trauma, spinal cord injury, tumor, and hypercoagulable-state patients; only mechanical prophylaxis was used for common elective spine surgeries.

To reduce the risk of infection, several types of antimicrobial agents and routines have been documented in the literature. For example, Bradywood et al²² required that patients take chlorhexidine showers or baths prior to surgery, given that preoperative bathing is believed to reduce bacterial load; Feng et al³⁴ administered 1.5 g cefuroxime close to time of incision³⁴; and Smith et al³⁶ administered 2 to 3 g of Ancef, 900 mg of Clindamycin, or 15 mg/kg Vancomycin.³⁶ These interventions were mostly perioperative in nature, with the exception of the chlorhexidine baths.

For PONV prophylaxis, Soffin and colleagues^37–39 employed both perioperative prophylaxis and postoperative treatments in a series of spine ERAS protocols. Perioperatively, patients at high risk for PONV were given a scopolamine patch (1.5 g transdermal) in the surgical holding area,^37,39 as well as 4 to 8 mg of dexamethasone on induction and 4 to 8 mg of ondansetron 30 minutes prior to emergence from anesthesia.³⁸ Postoperatively, PONV was treated with IV metoclopramide (10 mg) or ondansetron (4 mg), plus a scopolamine patch (1.5 mg transdermal) if PONV was refractory.^38,39 Carr et al³⁰ also administered IV ondansetron intra-operatively as prophylaxis. Bednar²¹ administered IV/PO dexamethasone 4 mg every 6 hours postoperatively until discharge.

Catheter and Surgical Drain Sparing

Several spine ERAS protocols emphasized sparing the use of Foley catheters and surgical site drains—either avoiding use or performing early removal (Table 3). The use of Foley catheters and surgical drains has been associated with postsurgical infection of the urinary tract and wound site, respectively. To minimize such complications and to facilitate patient mobility, Ali et al²⁷ reported significantly decreased Foley catheter placements intraoperatively, as well as postoperatively for patients without bed restrictions; however, there was no significant difference in complication rate (which included infection rate) in pre-ERAS intervention versus post-ERAS intervention patients in this study. Staartjes et al⁴⁰ used surgical drains only for patients who underwent mini-open decompression or MIS PLIF procedures; the authors also stressed the removal of catheters and drains as soon as possible postoperatively. Likewise, Debono et al²³ and Sivaganesan et al³⁵ reported no drain use for lumbar microdiscectomy and various elective spine surgery procedures, respectively; Debono et al³³ described a drastic reduction in drain use for ACDF, ALIF, and PLIF procedures; Soffin et al³⁷ omitted the use of catheters or drains for ACDF and cervical disc arthroplasty (CDA) surgeries.³⁷ Wang et al²⁴ avoided the use of a Foley catheter altogether. In studies that did not emphasize catheter or wound drain sparing, most documented removal on POD1^31,36 or POD2/3^22,30,32 in order to facilitation mobilization.

Postoperative Pain Modulation

In addition to perioperative medication regimens for patients undergoing spine surgery (see the “Preemptive Analgesia” and “Intraoperative MMA” sections), postoperative MMA measures have been implemented. A variety of MMA combinations have been administered to supplement PCA opioid consumption. Common elements of a postoperative MMA cocktail include gabapentin/pregabalin,^{22,24,25,32,34–36,38,39} acetaminophen,^{22,24,25,27,30,32,37–39} and celecoxib and other NSAIDs.^{22,25,27,33–40} Other nonopioid options include dexamethasone,²⁷ paracetamol,⁴⁰ and ketamine.²⁸ To maximize opioid sparing, some studies also avoided the use of long-acting opioids^24,40 and implemented early discontinuation of PCA.²² For various types of lumbar decompression surgeries, Soffin et al³⁸ stratified postoperative MMA and opioid use based on numeric rating scale pain scores: patients with numeric rating scale scores of 4 or less only received nonopioid interventions (acetaminophen, ketorolac, gabapentin); patients with scores 5 to 7 could receive 50 mg of tramadol; and patients with scores 8 to 10 received 5 mg of oxycodone.³⁸ Interestingly, Soffin and colleagues found decreased perioperative opioid consumption, but no significant changes in postoperative pain scores or opioid consumption compared with the pre-ERAS control group. For 1- or 2-level lumbar fusion procedures, Smith et al³⁶ administered a postoperative cocktail of 200 mg of celecoxib PO, 300 mg of gabapentin PO, and 975 mg of acetaminophen PO; the authors reported a decrease from 7% to 0% in PCA use and a decrease from 14% to 5.2% in the use of long-acting opioids.

Importantly, several research groups have investigated the effects of postoperative MMA for non-ERAS spine surgery, which yielded varied outcomes.^45,47,61,62 In a randomized controlled trial, Korkmaz et al⁶¹ studied the effect of either IV 1 g of metamizol, 1 g of paracetamol, or 8 mg of lornoxicam supplementation after wound closure for lumbar disc surgery. These analgesics were administered in tandem with conventional postoperative PCA of morphine.⁶¹ The authors reported decreased VAS pain scores in the first 24 hours after surgery for patients who received metamizol and paracetamol, but not lornoxicam; PCA use in the paracetamol group also significantly decreased over time.⁶¹ Other studies demonstrated the postoperative use of MMA pain management with nonsteroidal anti-inflammatories (NSAIDs) and GABA-acting drugs. Mathiesen et al⁴⁵ compared the administration of a cocktail of acetaminophen, NSAIDs, gabapentin, S-ketamine, and dexamethasone versus PCA morphine in patients undergoing spinal fusion surgery. Results suggest that patients who received the MMA cocktail required less opioid consumption and could mobilize earlier with physical therapy compared with control patients who only depended on PCA morphine.⁴⁵ Likewise, Garcia et al⁶² studied the effect of giving celecoxib, pregabalin, and extended-release oxycodone supplementation for PCA morphine compared with the IV morphine infusion alone. Total morphine consumption and VAS scores were lower in patients receiving the MMA regimen compared with control.⁶² Finally, a meta-analysis by Yu et al⁴⁷ analyzing the use of pregabalin and gabapentin in the postoperative period demonstrated that gabapentin PO was efficacious in the management of postoperative pain at all time points on POD1, and thus may significantly reduce total opioid consumption without increasing the incidence of adverse effects. Pregabalin also was found to be efficacious in the management of postoperative pain, but more trials were needed to further evaluate its effectiveness.⁴⁷

Early Mobilization and Physical Rehabilitation

Early mobilization of the patient is a critical prerequisite for achieving early discharge, which is one of the goals of ERAS. Here, early mobilization is defined as getting the patient out of bed on POD0 or POD1,⁶³ which may involve physical therapy, occupational therapy, or other exercises. In a review of the effects of early mobilization after various types of surgeries, Epstein⁶³ described correlations with reduced morbidity and LOS. However, research on mobilization/rehabilitation following spine surgery remains scarce. Nielsen et al⁶⁴ implemented a pre-habilitation (6- to 8-week exercise regimen and smoking/drinking cessation) and early rehabilitation program for patients undergoing surgery for degenerative lumbar disease; the authors reported reduced LOS and improved patient satisfaction for patients who received this intervention, although postoperative complication rate and pain did not significantly change.

Although only 1 ERAS protocol included a “pre-habilitation” regimen,²⁸ many other protocols encourage early mobilization and provided physical rehabilitation services (Table 4). In the ERAS protocols, patient mobilization started as early as less than 90 minutes after arrival at the PACU following a laminectomy/laminotomy/microdiscectomy procedure.³⁸ Early mobilization goals included independence in performing log roll,²² movement out of bed and to chair 3 times per day,^25,39 working with physical therapy/occupational therapy,^{25,31,36–39} or even being discharged after surgery.²⁰ Most protocols did not provide much detail beyond when early mobilization began and whether physical therapy/occupational therapy was offered; even then, there was considerable variety in early mobilization requirements. Because of the paucity of research on this topic, there seems to be no consensus on which features of early mobilization and physical rehabilitation are most beneficial to patients.

Early Nutrition

Early commencement of postoperative enteral nutrition is an established ERAS intervention in other surgical specialties. For instance, in the ERAS guidelines for colonic resection² and rectal/pelvic surgery,⁶⁵ early oral intake of liquids, solids, or nutritional supplements is recommended.² Indeed, early postoperative enteral nutrition may decrease postsurgical infection rates, reduce LOS and hospital cost, and reduce postoperative ileus when compared to late enteral or parenteral feeding.^66–70

Early nutrition was commonly advised for spine surgery patients treated under ERAS guidelines (Table 4). In the spine ERAS protocols, a subset of studies initiated a clear liquid diet at POD0 or POD1 that advanced to a regular diet as tolerated,^22,25,34,40 whereas others permitted a regular diet of solids and liquids on POD0 or POD1.^{30,32,36,38–40} Some protocols initiated oral intake as soon as the patient recovered from anesthesia.^34,37–39 These early nutrition guidelines were similar across the different ERAS protocols, regardless of whether the patients had undergone major or minor surgery.

Early Discharge Criteria

Currently, there does not seem to be a consensus on the criteria for early discharge in spine surgery (Table 5). This diversity may be due in part to the different spine procedures for which the protocols were developed. Nevertheless, current ERAS discharge criteria include physical therapy clearance, pain control, mobility, tolerating diet, and scoring systems such as the Aldrete³⁷ and Chung postanesthetic discharge scoring system.^23,33,71