Adverse Events in Spine SurgeryCHAPTER 1

Since the time of Hippocrates, safety has been a concern in the medical field and “Primum non nocere,” “First do no harm,” has been part of the Hippocratic Oath. For every surgeon, a good patient outcome has been a primary aim after surgery. But during the treatment, patient has to pass through many processes which are often regarded as unremarkable and usual. During this process and course of hospitalization, there are many potential risks of harm to the patient, resulting in prolonged hospitalization, increasing cost, poor outcome, or even death. Many times these risks are preventable and never known to the patient and are passed off silently. From the patient's point of view, whenever a patient agrees to undergo surgery it is his right to have an assurance that the whole process will go safely so they have the best chance possible medically of achieving the desired outcome. In June 1998, Quality of Health Care in America was initiated by the Institute of Medicine (IOM), to improve the safety of health care and the first document “To Err is Human: Building a Safer Health System” published in 2000 brought out the serious issues affecting the quality of health care and future recommendations to improve the systems.¹ Since then there is a lot of awareness regarding the issue of patient safety, adverse events (AEs), medical errors, and the immediate need to focus attention to curb it. Spine surgery is not immune to healthcare quality services and AEs. Inherent complexity in spine surgery, fast-changing new technology, increasing age with comorbidity in patients, increased awareness for spine surgery, and a large volume of spine surgeries may contribute to all these.

The terms “adverse events” and “complications,” are poorly defined in the literature and often used interchangeably. This leads to a lack of standardized reporting of AEs in the literature. Harvard Medical Practice Study defined an AE as an “injury that was caused by medical management (rather than the underlying disease) and that prolonged the hospitalization, produced a disability at the time of discharge, or both.”² This means the patient suffers from the undesirable effect produced from the intervention rather than the underlying disease itself. According to Stedman's Medical Dictionary “Complication is a morbid process, occurring in the course of a disease, which is not an essential phenomenon of that disease; it may be an occasional or unusual result of the primary disease or may arise from entirely independent causes.”³ To make these definitions simpler “AEs” were defined as any unexpected or undesirable event(s) occurring as a direct or indirect result of surgery and a “complication” was defined as a disease or disorder, which, as a direct or indirect consequence of a surgical procedure, will change the expected outcome 2of the patient.⁴ Therefore, an AE may turn into a complication but an AE may occur without any complication or change in the expected outcome of the patient. For example, if there is a misplaced pedicle screw, it is an AE that may not cause any root injury, but if it causes a root injury and causes clinical consequence of nerve paralysis, then it becomes a complication. Hence, AEs can be reversed if found out without any harm to the patient. Many AEs may also go unnoticed if it does not produce any complication. These AEs if occur and cause no harm to the patient, it is a “near miss” or “close call.” AEs can be preventable and nonpreventable. Preventable AEs are those which can be prevented by applying a standard of care and accepted strategies for prevention. The concept of safe spine surgery is to apply these strategies to prevent AEs to occur during the treatment of the patient. An AE can become a negligent act if it occurs and has come into notice but is not addressed immediately. If the pedicle screw is seen during surgery injuring the nerve root but if the misplaced screw is not changed, the act is an AE with negligence.

It is difficult to exactly know the prevalence of the AEs during surgery as the events without any clinical consequences are never reported or these events are never considered as AEs as they are immediately corrected during the treatment. Hence, there is under-reporting of the AEs.⁶ Even surgeons though know the importance of reporting AE, they report only the major AEs while they cannot register the minor AEs.⁷ Moreover because of poor documentation of AEs in records, retrospective studies are poor compared to the prospective studies.⁸ Most of the literature is on the complications following spinal surgery. The complications in spine surgery vary from 7% to 28.8%.^8–12

Surgical AEs usually can be caused by the convergence of multiple factors at multiple levels rather than single individuals. With a busy surgical schedule and at high-volume spine centers, preventable errors can occur at multiple points. These can be from the systems failures—the clinicians, administrations levels, nursing levels, laboratory staff and reports, operation theater staff, spinal implants and implant ordering, interdepartmental communications, patient counseling, surgical execution, surgical equipment failures, and postoperative management. It can occur because of the patient factors—comorbidities, anticoagulant drugs, thromboprophylaxis, urinary tract infections, osteoporosis, and lack of patient optimization before surgery. The most important of all the factors is human failure. It can be a failure in decision-making and planning of surgery, selections of right procedure, surgeon's competence, or execution failure. To avoid these human failures, there are checklists and protocols. It can also occur when the protocols are not followed and rely much on the individual surgeon's memory.

The number of spine surgeries has shown an exponential rise in the last decade. This is because of many factors such as understanding of the disease, diagnostic modalities, technological advancements, improved surgical techniques, minimally invasive approaches, safe anesthesia techniques, and improved critical care management. Moreover, there is increased awareness of spine surgery because of improved patient outcomes. More complex surgeries are being offered to the geriatric population in form of complex deformity corrections. These patients are frail with a lot of comorbidities and require strict monitoring during the perioperative phase. With the increased volume of surgeries, complex surgeries, and geriatric population, the risk of AEs has also increased. Schoenfield et al. in a large retrospective cohort of 5,887 patients studied to determine the association between the patient demographic factors, comorbidities, nutritional status, and surgical characteristics, and the occurrence of mortality and complications after spinal arthrodesis. 10% suffered a complication and 0.42% was the mortality. Wound infection was the most common complication. Age and pulmonary compromise were factors for the risk of mortality. Age, pulmonary conditions, body mass index (BMI), history of infection, ASA classification >2, neurologic conditions, resident (i.e., trainee) involvement, and procedural times exceeding 309 minutes increased the risk of complications. Serum albumin 3.5 g/dL or less increased the risk of mortality, complications, wound infection, and thromboembolic disease.²⁰

There is no standardized method of grading or reporting of the AEs. In literature there is lot of inconsistency in defining, classifying, and reporting of the AEs.5

Many of them use loose terms like “minor” and “major” AEs. Even there is no clear cut difference between the use of “complication” versus “AEs.” In 2010, in a single center prospective review to classify the AEs, Spine AdVerse Events Severity system (SAVES) was developed combining the criteria of AE causing type of clinical effect (temporary or permanent), requiring type of treatment, increased length of stay, production of long-term clinical sequelae, and death.²² This version was further modified and developed six grades of severity of AEs. This SAVES-V2 was validated by Spine Trauma Study Group and Degenerative Spine Study Group in 2016 with good interobserver reliability.²³

The key goal to reduce the AE and medical errors is to prevent them to happen. There are multiple causes and multiple points in the whole process from the admission of a patient to discharge and postoperative phase which can cause AE or error. This requires not an individual approach but a check at each level of the whole system similar to the aviation industry, defense, and armed forces or nuclear power plants where even a minor error is not acceptable. Since more than half of the AEs are preventable, every focus should be on how to prevent these unforeseen preventable AEs to make the patient's surgical experience safe with positive surgical outcomes. Safe surgical protocols, surgical checklists, and multidisciplinary team approach help curb these errors.

Forming a safe surgical protocol is extremely important to prevent some of the unforgivable AEs that can happen and improve the safety, recovery, and outcome of the patient in spine surgery. The four most common errors in spine surgery are operating on the wrong patient, performing the wrong procedure, wrong level surgery, and wrong site/side surgery. As recently till 2019 by Watts et al. reported a 50% incidence of wrong level spine surgery over spine surgeons’ careers despite the availability of intraoperative fluoroscopy 6to confirm the levels.²⁴ Following the Universal protocol by World Health Organization (WHO) of three steps of verification (correct patient, correct site, and correct procedure), Marking the site and time out and 3Rs (right patient, right side, and right procedure) have drastically decreased these errors.^25,26 There are similar protocols for improving the safety of the patient and decreasing the AEs and improving the outcomes. Enhanced recovery after surgery (ERAS) protocol for faster recovery of the patient is one of them.

The surgical checklist aims to improve the safety of the patient by reducing the AEs and complications at each stage of the management of the patient and reducing the “human errors” and lapses that can occur in busy surgical and hospital schedules in healthcare management. It also enhances the teamwork, efficiency, and interpersonal and interdepartmental communications and safety culture in the healthcare professionals. As far as surgical safety is concerned, WHO introduced the Surgical Safety Checklist in 2009.²⁵ The introduction of this checklist has reduced the complication rates in spine surgery.¹⁰ Though the WHO checklist is for any surgical procedure of any specialty in the operation theater, a specific checklist for spine surgery and during preoperative, operative, and postoperative periods can still further be helpful. A similar checklist proposed recently for spinal surgery has shown a reduction in preventable AEs after its implementation.²⁷

Complex spine surgeries such as spinal deformity corrections, spinal tumor surgeries, and revision spine involve a long duration of surgery, extensive blood loss, and patient comorbidities leading to high complication rates. A systematic protocol-based multidisciplinary team approach in the perioperative phase for preoperative patient optimization and counseling, intraoperative management by dual surgeon and anesthesia team, and postoperative management have shown a 51% reduction in complication rates. This shows the importance of working with the team in complex spine surgery cases to reduce the AEs.²⁸

In spine surgery, there are lot of technological advances to improve the safety and quality of surgical procedures. All these technologies from diagnostic modalities to operation theater equipment are primarily advancing to improve safety during the surgical procedure and to improve patient outcomes. These are intraoperative neuromonitoring, microscope, endoscopes, technologies for bleeding control, ultrasonic bone scalpel or navigation, and robotics to increase precision. All these come at an expense but improve safety. These factors are considered elsewhere in this monograph.

For any surgical procedure, a surgeon is the captain of the ship. It depends on the surgeon in whom the patient has submitted himself with full faith, how the patient undergoes his procedure with full safety. The surgeon has to be technically competent but also needs to regularly update, re-train, keep pace with newer safe technologies, and adopt newer technical skills with advancements. But it is not only the surgeon's technical skill and knowledge that are an important aspect for the patient but there are certainly other important qualities that make the whole process uneventful. Surgical competence, 7sound clinical decision-making, and leadership from evaluation of the patient to discharge and follow-up constitute the mainstay of the patient's safety. The unique part of a patient's surgical care is that the patient must be managed in a complex, dynamic, and interdependent environment with a lot of interactions with the healthcare system professionals may be administrative staff, nursing staff, interdisciplinary medical staff, or operation theater personnel. Any AEs during the whole process are the responsibility of the surgeon. These are the nontechnical skills of the surgeon in form of leadership, communication and teamwork, task management, situation awareness, and decision-making important for safety and reducing the AEs. In a survey to find out attributes and qualities of safe practitioner technical skills (98%), crisis management (98%), and honesty (97.5%) as the most important, while technical skills (98%), anticipation, preparedness (84%), and organizational skills/efficiency (83%) were the most trainable.²⁹

Adverse events are part of any surgical procedure, but spine surgery is a lot more complex with complications more disabling to the patient. AEs can occur at any stage during the whole process of surgical patient care. Patient safety is of prime importance and every effort should be made to mini- mize the preventable AEs occurring and improve the outcome of the patient. Identifying the standard risk factors, optimizing the patients before surgery, and following standard checklists and protocols are of utmost importance to prevent these AEs to occur. The surgeon should deliver quality service, should be safety conscious, and develop a safety culture among the peers. It is also important to invest in advanced technology, techniques, and training to improve patient safety.