Outcome Assessment in Nurse Anesthesia


Outcome Assessment in Nurse Anesthesia


Michael J. Kremer and Margaret Faut Callahan


Chapter Objectives

1.  Describe the historical influences on outcome assessment of nurse anesthesia practice

2.  List constraining variables that limit research opportunities in the area of nurse anesthesia outcomes

3.  Review the outcomes to date of linking pay to performance for surgical procedures

4.  Suggest next steps for cost-effectiveness analyses of nurse anesthesia care

5.  Examine the role of human patient simulation in knowledge transfer to the clinical area and risk reduction

6.  Discuss the risks for certified registered nurse anesthetists (CRNAs) associated with participation in prospective, multicenter anesthesia outcome studies


Chapter Discussion Questions

1.  What was the impetus for the development of closed malpractice claims research in anesthesia?

2.  What is the relationship between human patient simulation and outcomes in anesthesia care?

3.  Why did investigators posit that Surgical Care Improvement Project (SCIP) compliance should not be used to determine Medicare and Medicaid reimbursement rates?

2084.  Regarding adverse perioperative outcomes, how is the role of anesthesia versus that of surgery in contributing to the adverse outcome determined?

5.  What enabling and constraining factors are related to the implementation of evidence-based practice (EBP)?





Nurse anesthetists have provided anesthesia care to patients in the United States for more than 150 years. This was the first advanced practice nursing specialty to have a certification exam, implemented in 1956. Successful examinees are known as certified registered nurse anesthetists (CRNAs). Some 50,000 CRNAs administer 43 million anesthetics annually in the United States (American Association of Nurse Anesthetists [AANA], 2016a).

Assessing outcomes of nurse anesthesia care is an essential component of CRNA practice. Participating in quality assessment activities is among the Standards for Accreditation of Nurse Anesthesia Programs, Practice Doctorate (2016) promulgated by the Council on Accreditation of Nurse Anesthesia Educational Programs (COA, 2016), the Scope of Nurse Anesthesia Practice (AANA, 2013a), and the Standards for Nurse Anesthesia Practice (AANA, 2013b). Studies have compared outcomes of care provided by various mixes of anesthesia providers (Dulisse & Cromwell, 2010; Hogan, Seifert, Moore, & Simonson, 2010; Lewis, Nicholson, Smith, & Alderson, 2014; Needleman & Minnick, 2009; Negrusa, Hogan, Warner, Schroeder, & Pang, 2016; Simonson, Ahern, & Hendryx, 2007) and have demonstrated satisfactory clinical outcomes with anesthesia provided by CRNAs. However, there are no prospective multicenter studies on anesthesia outcomes.

Methodological challenges in anesthesia outcome research include the various mixes of anesthesia providers and the complexity of health care settings where anesthesia services are delivered. CRNAs provide anesthesia services in hospital operating rooms, labor and delivery suites, and in numerous ancillary areas, including cardiac catheterization laboratories, endoscopy suites, and interventional radiology settings. CRNAs may be the sole anesthesia providers in rural and medically underserved areas as well as in forward-deployed military operations (Liao, Quraishi, & Jordan, 2015). Anesthesia in ambulatory surgery centers and office-based practices may be provided by a CRNA working collaboratively with a surgeon, dentist, or podiatrist. In some clinical settings, an anesthesiologist may work collaboratively with two to four CRNAs administering concurrent anesthetics.

The earliest outcome research in nurse anesthesia was conducted by pioneering nurse anesthetist Alice Magaw. Magaw was a nurse anesthetist at the Mayo Clinic and published a paper in the Northwestern Lancet in 1899 detailing over 3,000 ether and chloroform anesthetics she administered without a fatality (Magaw, 1899). These anesthetics were administered to patients undergoing operations ranging from general to orthopedic; ear, nose, and throat; gynecological; and urological surgeries. Note that endotracheal intubation was not common until the mid-20th century, and that Korotkoff did not identify the five sounds associated with blood pressure measurement until 1905. Magaw published a total of five peer-reviewed papers, including “Observations Drawn From 209Experiences of Eleven Thousand Anesthesias” (Magaw, 1904) and “A Review of Over Fourteen Thousand Surgical Anaesthesias” (Magaw, 1906).

It is likely that subsequent legal challenges to nurse anesthesia practice were defeated through the documentation of safe, quality care provided by Magaw (Bankert, 1989). Like Nightingale (McDonald, 2001), this nurse anesthesia leader recognized that in addition to clinical excellence, documenting clinical outcomes and disseminating research findings in peer-reviewed literature were requisites of professionalism. Magaw’s outcome research also influenced the pivotal 1917 judicial ruling in the Frank v. South case where a Kentucky court found that when anesthesia is practiced by a nurse, it is the practice of nursing, and when anesthesia is practiced by a physician, it is the practice of medicine (Blumenreich, 1990).


Municipal or state-level study commissions that examined anesthetic morbidity and mortality in the 1930s and 1940s were hampered by the unwillingness of anesthesia providers to share their data (Ruth, 1945). No concerted effort was made to track anesthetic outcomes until the 1950s.

The first large-scale study of anesthesia morbidity and mortality was conducted by Beecher and Todd (1954). Muscle relaxants were found to be significantly associated with anesthetic morbidity and mortality. Almost 60 years later, investigators noted a high incidence of postoperative residual blockade in contemporary anesthesia practices, despite the advances in pharmacology, technology, and provider education (Murphy, 2012).

In the 1970s, a rapid increase in malpractice insurance premiums prompted a new research method for investigating anesthetic outcomes: analysis of closed malpractice claims. Pioneered by the National Association of Insurance Commissioners, this methodology was adopted by the American Society of Anesthesiologists (ASA), which has conducted the largest anesthesia closed claims study to date with nearly 9,000 cases reviewed (Brunner, 1984; Cheney, 2010; Metzner, Posner, Lam, & Domino, 2011). Over 50 publications in peer-reviewed journals have emanated from this study, often with the focus of lessons learned in specific practice-related areas such as equipment, airway management, and specialty practice areas. Recent publications include risk factors associated with ischemic optic neuropathy after spinal fusion surgery (Lee et al., 2012); cervical spinal cord, root and bony spine injuries (Hindman et al., 2011); injury and liability associated with cervical procedures for chronic pain (Ramthell et al., 2011); and malpractice claims associated with medication management for chronic pain (Fitzgibbon et al., 2010).

The American Association of Nurse Anesthetists Foundation (AANAF) has also conducted a closed claims study that is methodologically similar to the ASA study. Peer-reviewed papers related to this study have also focused on lessons learned in specific areas such as preinduction activities and the genesis of perioperative respiratory, peripheral nerve, and other injuries (Jordan & Quraishi, 2015; MacRae, 2007). Distinctions in outcomes among anesthesia providers have not been described in these studies.

Research findings from both the AANAF and ASA studies demonstrate that the process of care, rather than patient acuity or procedure complexity, is most frequently associated with outcomes that are not optimal (MacRae, 2007). Human patient simulation has been 210used as an instructional tool for clinicians and trainees to foster improved decision making and reinforce principles of care to decrease the incidence of adverse outcomes. Maintenance of certification programs may utilize simulation as well as other instructional methods to assess continued professional competence (AANA, 2016b).


The use of human patient simulation in the context of high-fidelity simulation labs provides trainees and practitioners with opportunities to develop crisis management skills in rarely occurring, potentially fatal scenarios as well as fostering nontechnical skills, such as clinical decision making (Turcato, Roberson, & Covert, 2008; Wunder, 2016). As human patient simulation has been increasingly incorporated in nurse anesthesia education, educators have developed rubrics for evaluation of student performance in simulation scenarios (Overstreet, McCarver, Shields, & Patterson, 2015).

The best features and practices of simulation-based education in health care have been described as:

image  Feedback provided to learners

image  Deliberate practice that occurs away from the bedside

image  Integration of simulation into health sciences curriculum

image  Measurement of outcomes that may be influenced by simulation

image  Fidelity of simulation

image  Acquisition and maintenance of skills, for example, management of difficult airways, placement of central venous catheters

image  Mastery learning, for example, the ability to practice skills in the simulation lab before performing the same skills at the bedside

image  Transfer of simulation-based learning to clinical practice

image  Team training

image  High-stakes testing

image  Instructor training (McGaghie, Darycott, Dunn, Lopez, & Stefanidis, 2011; McGaghie, Issenberg, Petrusa, & Scaelse, 2010)

The impact and educational utility of simulation-based education in health care are likely to increase in the future. However, simulation labs currently vary significantly in terms of their infrastructure and available resources. The Society for Simulation in Healthcare (SSiH) has developed criteria for the certification of simulation instructors and accreditation standards for simulation labs. At the time of writing, 54 of over 300 simulation labs worldwide have fulfilled the criteria for SSiH accreditation (SSiH, 2015). Recent papers in peer-reviewed journals attest to the growing contributions of human patient simulation in the areas of safety and quality in clinical care (Kim, Park, & Shin, 2016; Stephens, Hunninger, Mills & Freeth, 2016; Wunder, 2016).

There is a developing body of research evidence showing that there is knowledge transfer from the simulation lab to clinical practice with beneficial effects on clinical outcomes. For example, clinicians who participate in simulation-based training on difficult airway management have decreased incidences of failed airway management scenarios. 211In addition to decreasing the potential morbidity and mortality associated with airway mishaps, operating room time and professional fees based on time are decreased when less clinical time is required to teach trainees these skills at the bedside. However, there remain critical challenges and gaps in research on the transfer of knowledge, skills, and abilities from the simulation lab to clinical practice (McGaghie et al., 2011).

Another use of human patient simulation that has been described occurs during the interview process for prospective nurse anesthesia students. Applicants are assigned to small groups and provided with a critical scenario in which they must work collaboratively (Penprase et al., 2012). This type of observed interaction and operationalization of critical care nursing skills may provide useful information that is predictive of the potential success of these applicants in a nurse anesthesia program.


As noted earlier, a methodological and design challenge for outcome research is that anesthetic mortality occurs rarely today, with approximately one death in 200,000 cases (Li, Warner, Lang, Huang, & Sun, 2009). The Centers for Medicare & Medicaid Services (CMS), the American Hospital Association, the ASA, the American College of Surgeons, and the Veterans Administration developed a strategy to reduce surgical morbidity over a 5-year period (Lema, 2003). The result of that collaboration was the SCIP. The goal of SCIP was to reduce surgical complication by 25%. These data are publicly reported on the CMS Hospital Compare website (Medicare, 2016). SCIP measures include the following:

image  SCIP Inf-1: prophylactic antibiotics are received within 1 hour before surgical incision

image  SCIP Inf-2: prophylactic antibiotic selection for surgical patients

image  SCIP Inf-3: prophylactic antibiotics discontinued within 24 hours after surgery end time

image  SCIP Inf-4: cardiac surgery patients with controlled 6:00 a.m. postoperative glucose

image  SCIP Inf-6: surgery patients with appropriate hair removal

image  SCIP Info-10: surgery patients with perioperative temperature management

image  SCIP Card-2: surgery patients on beta-blocker therapy before arrival who received a beta-blocker during the perioperative period

image  SCIP VTE-1: surgery patients with recommended venous thromboembolism (VTE) prophylaxis ordered

image  SCIP VTE-2: surgery patients who received appropriate VTE prophylaxis within 24 hours before surgery to 24 hours after surgery (Thiemann & McFadden, 2010)

SCIP compliance affects Medicare and Medicaid reimbursement rates. Studies have examined compliance with the SCIP surgical site infection (SSI) module, requiring prophylactic antibiotic administration 1 hour prior to surgical incision to determine whether compliance with SCIP correlated with SSI rates reported by the National Surgery Quality Improvement Program (NSQIP) data for the same period. The authors found no statistically significant association in patients whose care failed SCIP Inf-1 guidelines and the rates of SSI. These investigators posited that SCIP compliance should not be used to determine Medicare and Medicaid reimbursement rates because there was no observed 212correlation between failure of SCIP Inf-1 and SSI (Garcia, Fogel, Baker, Remine, & Jones, 2012). Other studies have demonstrated a modest association with process measures and patient outcomes (Thiemann & McFadden, 2010).

CMS has developed the Ambulatory Surgical Center (ASC) Quality Reporting (ASCQR) Program, which is a pay-for-reporting, quality data program. Under this program, ASCs report quality of care data for standardized measures to “receive the full annual update to their ASC annual payment rate” (CMS, 2016a). These measures include:

image  Patient burns

image  Patient falls

image  Wrong site/wrong side/wrong patient/wrong procedure/wrong implant

image  Hospital transfer/admission

image  Prophylactic antibiotics within 1 hour of procedure

image  Use of patient safety checklist, for example, World Health Organization (WHO) checklist (WHO, 2012). Facility volume data on selected procedures

image  Influenza vaccination coverage among health care providers (CMS, 2016a)

As members of multidisciplinary teams providing perioperative care in both inpatient and outpatient settings, CRNAs exert leadership daily, helping to ensure compliance with regulatory guidelines. Measures of compliance with these guidelines reflect the outcomes of direct patient care and leadership provided by CRNAs.

Regarding variables related to anesthesia care, it is difficult to classify anesthesia-specific events versus surgery-specific events. Outcomes such as epidural abscesses following neuraxial anesthesia or patient awareness under general anesthesia are more likely to be associated with anesthesia care. However, there is not a validated algorithm to identify outcomes directly related to anesthesia care (Thiemann & McFadden, 2010).

As noted earlier, there are no ongoing prospective multicenter studies of anesthesia outcomes. Creation of a national health information network (NHIN) will facilitate national quality improvement activities. The NHIN is a set of standards, services, and policies that allow for secure web-supported health information exchange. This network provides a foundation for exchange of health information across diverse entities. NHIN is a simple, secure, scalable standards-based method for participants to send authenticated, encrypted health information directly to known and trusted recipients over the Internet (HealthIT, 2016). Outcomes tracked in this manner can provide data that substantiate the safety and quality of services provided by CRNAs and other advanced practice registered nurses (APRNs).

Performance measures are critical to the national effort to ensure that patients receive appropriate and high-quality care. Pay for performance (P4P), or value-based purchasing, has endeavored to link clinical outcomes with reimbursement. P4P also includes disincentives for negative consequences of care or increased costs for “never” events, for example, wrong-site surgery, operative or postoperative complications, and medication errors (Agency for Healthcare Research and Quality [AHRQ], 2012a).

Investigators used Medicare data to examine 30-day mortality among over 6 million patients who had acute myocardial infarction, congestive heart failure, or pneumonia, or who underwent coronary artery bypass grafting between 2003 and 2009. These researchers found no evidence that the largest hospital-based P4P program led to decreases in 21330-day mortality among these patients and suggested that expectations for improved outcomes related to P4P should be modest (Jha, Joynt, Orav, & Epstein, 2012).

Accountable care organizations (ACOs) consist of provider groups that voluntarily collaborate to give high-quality care to Medicare patients. The intent of coordinated care is to limit unnecessary duplication of health care service as well as prevent medical errors. When ACOs deliver high-quality care while containing costs, they share in the savings achieved for Medicare (CMS, 2016b). Given the large number of Medicare beneficiaries who undergo surgery each year, ACOs provide a mechanism to quantify the contributions of CRNAs and other APRNs while contributing to cost containment.

The Physician Quality Reporting System (PQRS) “is a quality reporting program that uses negative payment adjustment to promote reporting of quality information by individual eligible professionals and group practices.” Those who do not satisfactorily report data on quality measures for covered Medicare Physician Fee Schedule (MPFS) services furnished to Medicare Part B beneficiaries will be subject to a negative payment adjustment under PQRS (CMS, 2016c). PQRS is applicable to CRNAs, since this provider group has had direct reimbursement under Medicare Part B since 1989.

Guidance on PQRS reporting for CRNAs is reported on the AANA website. Related issues include:

image  Verification of correct reporting and whether a payment adjustment will be provided

image  Information included in individual PQRS feedback reports

image  The process for requesting a review of PRS payment adjustments

image  Reasons for receiving a negative payment adjustment

Reimbursement models that reflect clinical outcomes continue to evolve. The Medicare Access and CHIP (Children’s Health Insurance Program) Reauthorization Act of 2015 (MACRA) will create two new payment systems for clinicians, affecting more than 600,000 physicians, nurse practitioners, physician assistant and therapists, the majority of the clinicians billing Medicare. In 2019, clinicians will be able to earn higher levels of reimbursement if they adopt new business modes called alternative payment models. That involves a willingness to accept financial risk and reward for performance, reporting quality measures to the government, and using electronic medical records. Most clinical practitioners are expected to follow a track called the merit-based incentive payment system that will feature a more modest financial risk and reward accounting system for quality, efficiency, and use of electronic medical records (Alonso-Zaldivar, 2016).


Nurse anesthetists are the primary anesthesia providers in rural America, which enables health care facilities in these medically underserved settings to offer obstetrical, surgical, and trauma stabilization services. In some states, nurse anesthetists are the sole anesthesia providers in nearly 100% of rural hospitals (AANA, 2016a). Little outcome research exists on anesthesia provided in rural America.

Rural CRNAs provide a broad range of anesthesia-related services within and outside of the operating room. One study found significant differences in the employment 214settings of medically directed and nonmedically directed CRNAs, the availability of certain anesthetic agents and monitoring devices, and the representation of surgical specialists based on the size of the rural community and hospital. However, this study did not examine anesthetic or surgical outcomes (Monti Seibert, Alexander, & Lupien, 2004).

An analysis of cesarean section outcomes showed no difference in complication rates when anesthesia was provided by a CRNA or a CRNA–physician team. Because solo CRNAs often provide anesthesia in rural settings, these findings help to quantify the outcomes of CRNA-provided anesthesia in rural settings (Simonson et al., 2007).

CRNAs provide more anesthesia services to citizens in vulnerable populations, including those with lower incomes, Medicaid-eligible, uninsured, and the unemployed, than do anesthesiologists. This is also reflected in the geographic maldistribution of anesthesia providers, with more CRNAs in rural and medical underserved settings and greater numbers of anesthesiologists in urban areas. The Affordable Care Act seeks to ensure that the population has adequate insurance coverage. Removal of barriers to CRNA scope of practice to maximize the delivery of anesthesia services by CRNAs will facilitate addressing the unmet health care needs of vulnerable populations (Liao et al., 2015).

“Placing unnecessary restrictions via limiting scope of practice for CRNAs may hinder patient access to a readily available workforce where patients may incur a higher indirect cost, i.e., travel expense, time off work, for an anesthesiologist’s care when a CRNA is nearby” (Liao et al., 2015). Geographic location as well as socioeconomic factors influence access to anesthesia care.


The safety and cost-effectiveness of care provided by CRNAs has been established in research findings (Dulisse & Cromwell, 2010; Hogan et al., 2010; Needleman & Minnick, 2009). The influence of scope of practice laws on outcomes by anesthesia providers has also been studied (Negrusa et al., 2016).

In one large commercial payer database, eight in every 10,000 anesthesia-related procedures have a complication. These complications were four times more likely in inpatient versus outpatient settings. The odds for complication differ with patient characteristics, including comorbidities, as well as the involved procedures. The probability of anesthesia-related complications is higher in procedures related to childbirth. However, the likelihood of anesthesia-related complications occurring is not affected by scope of practice laws or anesthesia delivery models, such as, CRNA only, anesthesiologist only, or mixed anesthesiologist and CRNA team. Patient characteristics, including comorbid conditions and the procedures requiring anesthesia are what affect anesthesia outcomes, independent of the anesthesia provider mix (Negrusa et al., 2016).

A Cochrane review studied the impact of increasing demand for surgery, cost-containment measures, and the anesthesia workforce on anesthesia outcomes. Analysis of six relevant studies with 1.5 million participants from Medicare in the United States and hospital records (Haiti) provided the basis for this review (Lewis et al., 2014).

Research findings demonstrated there was no difference in anesthesia-related mortality based on whether the anesthesia was provided by a nurse anesthetist or an 215anesthesiologist. The findings of one study indicated that anesthesia-related mortality was lower for solo nurse anesthetists versus nurse anesthetists supervised by anesthesiologists. Variations between studies and complication rates depending on the anesthesia provider were also noted. Since much of the data used for this analysis came from large databases, inaccuracies in reporting may have occurred. Differences that may have accounted for the variability in reported results included patient acuity, analytic methods, and funding sources for the reported research. Since data were not of consistent quality and studies presented inconsistent findings, it was not possible to demonstrate differences in the care provided by anesthesiologists and nurse anesthetists (Lewis et al., 2014).


The AANAF began in 1981. The mission of the foundation is “to advance the science of anesthesia through education and research.” As the philanthropic arm of the AANA, the foundation raises funds and invests in projects that directly support the nurse anesthesia profession (AANAF, 2016).

The AANA and AANAF support health services research endeavors in these areas:

image  Health policy

image  Science of anesthesia

image  Education

image  Practice/clinical

image  Leadership (AANA, 2016c)

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Dec 7, 2017 | Posted by in NURSING | Comments Off on Outcome Assessment in Nurse Anesthesia

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