Pa Patient Saf Advis 2018 Dec;15(4).
From the Database: Deaths after Ambulatory Surgery
Anesthesia, Nursing, Surgery
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Kim Liberatore, MSN, RN, CPHQ
Patient Safety Analyst
Pennsylvania Patient Safety Authority


The variety and complexity of procedures performed in the ambulatory surgical setting continue to expand and to offer an economical, efficient, convenient option for healthcare delivery.1 This growth has generated interest in the quality and safety of ambulatory surgery amongst many, including prospective patients, payers, and regulators. Analysis of patient deaths can help to inform proactive risk reduction strategies and the continuous improvement of ambulatory surgery. 


Analysts queried the Pennsylvania Patient Safety Reporting System (PA-PSRS) database for events occurring in ambulatory surgical facilities (ASFs) from January 1, 2008, through December 31, 2017, with a harm score of I (i.e., an event occurred that contributed to or resulted in death)2 or containing the keyword death, died, dead, expired, ceased to breath (CTB), passed away, or pronounce. This time period represents a 10-year span of data.

Designation of the facility type ASF in PA-PSRS aligns with the Pennsylvania Department of Health definition, "a facility or portion thereof not located upon the premises of a hospital which provides specialty or multispecialty outpatient surgical treatment."3 Reports from hospital-based outpatient departments and physicians' offices performing outpatient procedures are not included in this analysis.

Analysts manually reviewed all reports to exclude those that did not describe a patient death (e.g., expired medication). The remaining reports were categorized by reported procedure, time of event (e.g., decompensation during or after treatment at an ASF), and type of complication. Postoperative mortality was defined as a report describing a death that occurred after discharge from an ASF. Events were analyzed by patient age, patient gender, procedure, time of event, and type of complication.

Freestanding ambulatory surgical facility utilization data from the Pennsylvania Health Care Cost Containment Council (PHC4)* was used to calculate rates of death after ambulatory surgery by total number of cases, patient age, and patient gender. The overall number of PHC4 cases included 1,949 invalid/null gender values and 115 null age values. Any values with fewer than 10 cases were suppressed in the utilization data query. A query of the annual number of cases was used for all calculations with the exception of the semiannual rate of ASF reports involving death per case, which used a query of the quarterly number of cases. QI Macros® 2016 (KnowWare International, Inc., Denver, CO) was used for control chart generation. To examine trends over time, Microsoft Excel was used to perform standard linear regression using time as the predictor variable.

* The Pennsylvania Health Care Cost Containment Council (PHC4) is an independent state agency responsible for addressing the problem of escalating health costs, ensuring the quality of health care, and increasing access to health care for all citizens regardless of ability to pay. PHC4 has provided data to this entity in an effort to further PHC4's mission of educating the public and containing health care costs in Pennsylvania.

PHC4, its agents, and staff, have made no representation, guarantee, or warranty, express or implied, that the data—financial, patient, payor, and physician-specific information—provided to this entity, are error-free, or that the use of the data will avoid differences of opinion or interpretation.

This analysis was not prepared by PHC4. This analysis was done by the Pennsylvania Patient Safety Authority. PHC4, its agents and staff, bear no responsibility or liability for the results of the analysis, which are solely the opinion of this entity.


The query identified 199 reports, of which 114 indicated patient death occurred after ambulatory surgery. Data obtained from PHC4 indicated 9,307,875 ambulatory surgery cases were performed in the same time period.

Event Type and Harm Score

The reports of patient death after ambulatory surgery were submitted in three event type categories, with 54.4% (n = 62 of 114) reported in the "other" event type, followed by 43.9% (n = 50) in the "complication of treatment/test/procedure" event type, and 1.8% (n = 2) in the "error related to treatment/test/procedure" event type.

About 84% (84.2%, n = 96 of 114) of reports were submitted as Serious Events with a harm score of I. Of the remaining 18 reports, 10 were submitted as non-I Serious Events, and 8 were submitted as Incidents with harm score ranging from A (i.e., unsafe condition) through D (i.e., event, no harm).*

The following is an example of a death after ambulatory surgery submitted as a Serious Event with harm score I in PA-PSRS:

Patient had a colonoscopy and was discharged. Coroner's office notified us [the ASF] that the patient was found dead in his home the next day.

Events Occurring at an ASF

Nearly 30% of reports described events occurring at an ASF (29.8%, n = 34 of 114). Events occurring during the procedure were most frequent (n = 19 of 34), followed by events occurring post-procedure (n = 12; Figure 1).

Figure 1. Timing of Events Described in ASF Reports Involving Death (N = 114)

The following are examples of reports describing events occurring at an ASF:

During colonoscopy, patient become hypotensive and desaturated. CPR initiated. Patient transferred to hospital where she was pronounced.

Patient found to have gastric-outlet obstruction; patient vomited and aspirated in the recovery room. Patient suctioned and intubated. Patient transferred to hospital and expired.

Procedures involving vascular access (e.g., dialysis catheter exchange) and the gastrointestinal system (e.g., colonoscopy, endoscopy) each accounted for about one-third of events occurring at ASFs (Table 1).

Cardiopulmonary arrest, preceded by signs and symptoms such as chest pain or hypotension, was the most frequently described complication involving death (n = 23 of 34; Table 2) occurring at ASFs. Patients undergoing vascular access procedures accounted for the highest number of cardiopulmonary arrests involving death (n = 10 of 23).

Table 1. Events Involving Death Reported by ASFs by Timing and Procedure Type ​ ​


PROCEDURE TYPE ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​
GastrointestinalVascular accessMusculoskeletalEyeGenitourinaryHead and NeckAnesthesia inductionNeurologicalPlastic surgeryOther*Unspecified Total
At an ASF1011320230012



After discharge 285111052032311






Note: Data reported through the Pennsylvania Patient Reporting System, January 1, 2008, through December 31, 2017.

ASF, Ambulatory surgical facility.

* "Other" was used for procedures such as breast and dermatologic.


Table 2. Events Involving Death Reported by ASFs by Timing and Complication Type ​ ​ ​ ​ ​ ​ ​


COMPLICATION TYPE ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​
Cardio-pulmonary arrest

Found unresponsive/


Myocardial infarctionPerforationPulmonary embolism





Drug overdoseRespiratory distressStrokeSyncopeOther*Unspecified Total
At an ASF2300103002004134
After discharge 91965624202232080

Note: Data reported through the Pennsylvania Patient Reporting System, January 1, 2008, through December 31, 2017.

ASF, Ambulatory surgical facility.

* "Other" event type includes air embolism, bleeding, chest pain, free air, hemopneumothorax, oversedation, suicide. 

Events Occurring After Discharge

About 70% of reports (70.2%, n = 80 of 114; Figure 1) described events occurring after discharge from an ASF. Reports described follow-up phone calls made by ASF staff and communication initiated by the coroner's office as two sources of this information.

The following are examples of reports describing events occurring after discharge from an ASF:

Patient with longstanding cardiac history underwent left retinal surgery. Received IV fluid in recovery room for low blood pressure. Patient met discharge criteria. Patient became unresponsive during transport home, and was taken to the hospital. Patient expired in emergency department.

Patient treated for clotted dialysis access and discharged. Patient found unresponsive the next day by son.

Procedures involving the gastrointestinal system were described in 35% of these reports (n = 28 of 80), followed by procedures involving the musculoskeletal system (13.8%, n = 11; e.g., carpal tunnel release), unspecified procedures (13.8%, n = 11), and procedures involving the eye (12.5%, n = 10; e.g., cataract repair; see Table 1).

One-quarter of reports provided insufficient detail to categorize the complication or cause of death, and in a little fewer than one-quarter of reports, the patient was found unresponsive or dead (Table 2). The risk of perforation after gastrointestinal procedures and pulmonary emboli after musculoskeletal procedures also appeared in the data.

Postoperative Day Zero or One

Overall and within the post-discharge time period, events occurring on postoperative day zero (the day of surgery) or one were the most common (45.6%, n = 52 of 114; see Figure 1).

Procedures involving the gastrointestinal system were most frequently described in these event reports (n = 16 of 52), followed by procedures involving the eye (n = 9), and the musculoskeletal system (n = 7).

Of the reports that described the circumstances surrounding the patient's death, the most common events included patient found unresponsive or dead (n = 14 of 52), cardiopulmonary arrest (n = 8), and myocardial infarction (n = 5).

Number of PA-PSRS Reports and Number of ASF Cases

Figure 2 shows the number of reports of death after ambulatory surgery and the number of cases performed at Pennsylvania freestanding ASFs from 2008 through 2017. Standard linear regression calculations indicate that the number of ASF cases is gradually increasing over time at a rate of about 13,800 cases annually (p <0.001). When combined to calculate a semiannual rate of reports per case, statistical process control analysis shows that the rate is stable and there is an average of 1.2 reports involving death per 100,000 cases (Figure 3).4,5 Standard linear regression calculations indicate that the change in the semiannual percentage of reports per case is not statistically significant (p = 0.709).

Figure 2. Total ASF Cases and PA-PSRS Reports Involving Death after Ambulatory Surgery

Figure 3. Rate of ASF Reports Involving Death per Case, Semiannual

Patient Age and Gender

ASF cases were 56% female and 44% male in the 10 years analyzed. ASF specialties with the greatest difference in the proportion of female-to-male cases included fertility care, cosmetic surgery (more female than male cases), and urology (more male than female cases). Figure 4 shows the rate of reports per 100,000 cases for both males and females. The overall rate of reports involving death per 100,000 ASF cases for the 10 years in aggregate was 1.32 for males and 1.15 for females.

Figure 4. Rate of ASF Reports Involving Death per 100,000 Cases by Gender

Analysis of the 10 years of data in aggregate demonstrates that while patients age 55 through 64 account for the highest number of ASF cases, patients age 85 or older account for the highest rate of reports per 100,000 cases (Figure 5).

Figure 5. Total ASF Cases and Rate of Reports Involving Death per 100,000 Cases by Age

Event Recommendations

Some PA-PSRS reports described follow-up actions to improve patient safety at ASFs. The following are examples of such strategies:

  • Improved preoperative screening of patients, with particular emphasis on comorbidities and risk factors, and communication with scheduling providers.
  • ACLS (advanced cardiovascular life support) certification for all registered nurses, with at least one certified registered nurse working each shift.
  • Routine mock code drills.
  • Streamlined emergency boxes [equipment and supplies] to promote easier use.
  • Annual infection control training.
  • Preoperative and postoperative monitoring with prompt recognition of changes and communication to a physician.
  • Discharge planning that includes patients being accompanied for the first 24 hours postoperatively.
  • Discharge teaching emphasizing signs and symptoms of postoperative complications and the importance of seeking prompt medical attention.
  • Timely follow-up phone calls.
  • Establishing a relationship with local emergency departments to facilitate communication about patients presenting to the emergency department after discharge from the ASF.

For additional recommendations, see Supplemental Material.

* Authority note: ASFs, and other facilities designated by the MCARE Act, must report patient care events in which harm occurred or could have occurred.6 It is not necessary for an error to be involved, nor for the harm to be preventable, for a death or unanticipated injury to be reported.7 An unanticipated death that is related to the care of the patient (with or without error) is reportable as a Serious Event. If the relationship between the patient's death and the care at the facility is unclear, this is reportable as a Serious Event. If the death is determined to be unrelated to the care at the facility, this is not a reportable event.

The details of the PA-PSRS event narratives in this article have been modified to preserve confidentiality.


Despite mandatory reporting laws, PA-PSRS data are subject to the limitations of self-reporting, including the complexities of selecting the appropriate harm score. Reports indicated that not all adverse events and deaths could be definitively linked to the care delivered at an ASF. Analyst ability to categorize the procedure, time of complication, and type of complication was limited to the information provided in the event narratives. Evaluation of the number of reports by procedure type compared with the number of cases by procedure type might further enhance analysis.


In the 10 years analyzed, the number of ASF cases increased annually, while the rate of reports involving death remained stable. ASFs may benefit from incorporating into their risk reduction efforts the patterns associated with higher risk identified in this analysis, such as special consideration of cases involving patients age 85 years or older, as well as the strategies shared by other facilities and in the Supplemental Material. Continued promotion of a reporting culture at ASFs may enhance future abilities to analyze outcomes at facility- and state-wide levels and inform improvement strategies.


Jonathan R. Treadwell, PhD, senior associate director, ECRI Institute–Penn Medicine Evidence-based Practice Center, and Andrew West, PhD, CMBB, Six Sigma Adventures, consulted on statistical testing for this article.


  1. Medicare Payment Advisory Commission (MedPAC). Report to the Congress: Medicare payment policy. Washington (DC): Medicare Payment Advisory Commission (MedPAC); 2018 Mar. 529 p.
  2. Pennsylvania Patient Safety Authority harm score taxonomy. Harrisburg (PA): Pennsylvania Patient Safety Authority; 2015. 1 p. Also available:
  3. Title 28, Part IV, Chapter 551: General Information, Subpart F: Ambulatory Surgical Facilities. In: Commonwealth of Pennsylvania Department of Human Services, Bureau of Human Services Licensing. Pennsylvania Code. Harrisburg (PA): Pennsylvania Department of Human Services; Also available:
  4. Carey RG, Stake LV. Improving healthcare with control charts: basic and advanced SPC methods and case studies. Milwaukee (WI): ASQ Quality Press; 2003. 194 p.
  5. Mohammed MA, Panesar JS, Laney DB, Wilson R. Statistical process control charts for attribute data involving very large sample sizes: a review of problems and solutions. BMJ Qual Saf. 2013 Apr;22(4):362-8. Also available: PMID: 23365140
  6. Medical Care Availability and Reduction of Error (MCARE) Act of March 20, 2002, P.L. 154, No. 13, Cl. 40. Available:
  7. Final guidance for acute healthcare facility determinations of reporting requirements under the Medical Care Availability and Reduction of Error (MCARE) Act, 44 Pa. Bull. 6178 (2014 Sep 27). Also available:

Supplemental Material

The following resources may support ambulatory surgical facilities' (ASFs) continuous improvement efforts.   


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