The impact of closed claims analysis in anesthesiology

The Closed Claims Project was started in 1985 by the American Society of Anesthesiologists (ASA) as part of a series of initiatives directed at improving the safety of patients undergoing anesthesia and surgery. The specific idea was that rising malpractice insurance costs could be reduced, first, by identifying the scope and causes of significant anesthesia-related patient injuries and, second, by making changes in practice. Over the past 30 years, the Project has successfully contributed to improvements in anesthesia patient safety, and malpractice insurance premiums for anesthesiologists have been substantially reduced. Detailed analysis of adverse outcomes with common patterns has provided valuable insights into important patient risk and safety problems. Discovery of recurrent trends has generated safety and education programs aimed to improve patient safety and the quality of anesthetic care.

Data collection and limitations

The database is a structured collection of adverse anesthetic outcomes from the closed claims files of medical liability insurance companies, which insure more than one third of anesthesiologists in the United States. Volunteer ASA members travel to participating medical liability insurance companies to review medical records, depositions, and analyses of closed malpractice claims against anesthesiologists. Clinical data (e.g., patient demographics, procedure, anesthetic technique, type and severity of injury, sequence of events leading to injury, and a detailed summary) as well as liability data (e.g., standard of care, claim resolution, and claim settlement) are collected. Claims for dental injury, the most common claim against anesthesiologists, are not included in the database.

It is important to remember that data concerning how many and what types of anesthetic agents and techniques have been administered by anesthesiologists insured by the companies are not known. Hence, relative risks of a particular anesthetic technique cannot be determined by the Closed Claims Project. The database consists of only claims against anesthesiologists, not other anesthesia providers or medical specialists, unless the provider or specialist worked with the anesthesiologist. In addition, malpractice claims are estimated to represent only 3% to 4% of all patient injuries due to negligence. Because the U.S. medical liability system is a tort-based system with plaintiff payment contingent upon a successful lawsuit, the database is biased for severe injuries that occurred in patients who received substandard care. However, the database does contain a wealth of clinical details of rare, severe, adverse outcomes, and it provides a snapshot of liability in the United States.

Overview of adverse outcomes and their causes

The database currently contains almost 10,000 claims. The three major adverse outcomes in the database are death (29%); nerve damage (peripheral nerve or spinal cord, 19%) or brain damage (10%); and all other complications (e.g., airway trauma, stroke, myocardial infarction), account for the remaining 42% of claims (Figure 238-1). Although various media outlets have given extensive coverage to the topic of awareness during anesthesia, awareness represents only 2% of the claims in the database and, hence, is not currently a major medicolegal risk in the United States.

The types of complications that are listed in the database vary with the type of anesthesia used (Figure 238-2). A greater proportion of claims for death involve death occurring during monitored anesthesia care, as compared with during general or regional anesthesia. Permanent nerve injury is more often associated with the use of regional anesthesia (see Figure 238-2).

Four categories of damaging events (i.e., events that caused the injury) account for almost two thirds of all claims: respiratory events (25%), regional nerve block–related events (19%), cardiac events (14%), and equipment-related events (11%). The causes of respiratory events include difficult intubation, inadequate oxygenation/ventilation, esophageal intubation, aspiration of gastric contents, and bronchospasm. Cardiovascular events include excessive blood loss, inadequate fluid replacement, embolism of a variety of causes, and myocardial infarction, among others. Equipment-related events are associated with the use of peripheral and central catheters, electrocautery, infusion pumps, and heating devices, as well as anesthesia ventilators and delivery systems.

Claims associated with acute or chronic pain management have increased since the 1980s and represent more than 15% of all claims collected against anesthesiologists (Figure 238-3). The marked escalation in pain-related claims corresponds with the increasing use of acute and chronic pain therapy over the past decade. Claims associated with obstetric anesthesia make up approximately 10% of current claims (see Figure 238-3).

An initial finding of the Closed Claims Project was that respiratory-associated adverse events (e.g., inadequate ventilation, esophageal intubation, and difficult intubation) accounted for most claims for death or brain damage in the 1970s and early 1980s. Review of these claims found that the use of pulse oximetry and capnography (or both) would have prevented most of these adverse outcomes. These findings contributed to the ASA adopting pulse oximetry and end-tidal capnography as standards for intraoperative monitoring during general anesthesia in the early 1990s.

A recent review of claims related to monitored anesthesia care found that oversedation, with respiratory depression from sedative or analgesic drugs, was the most important cause of injury during monitored anesthesia care. More than half of claims were judged to have been preventable with the use of better monitoring, including pulse oximetry, capnography, or both. Similarly, monitored anesthesia care was associated with half of the 87 claims for injuries that occurred with anesthesia taking place in remote locations. Respiratory depression secondary to oversedation during monitored anesthesia care accounted for more than a third of remote-location claims. Substandard care, preventable by better monitoring, was implicated in the majority of claims associated with death. These findings contributed to the ASA adding end-tidal capnography as standard for intraoperative monitoring during monitored anesthesia care in 2011.

Lessons learned from the ASA closed claims project

Analysis of the Closed Claims Project database has contributed to the use of pulse oximetry and capnography as standards during general anesthesia. Consequently, anesthesia mishaps, particularly those related to inadequate ventilation and esophageal intubation, have decreased since the early 1990s. Recent claims have demonstrated the advantages to using capnography to monitor ventilation during monitored anesthesia care.

Injuries for difficult tracheal intubation motivated the ASA to develop practice guidelines for the management of the difficult airway. As a result, rates of death and permanent brain damage have decreased during the induction of anesthesia. However, claims related to the management of difficult airways, particularly during emergence and recovery from anesthesia, continue to occur.