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EDOU staffing by PAs: What are the effects on patient outcomes?

Sherwood, Kelly PA-C; Sugerman, Steven PA-C; Bossart, Philip MD; Bledsoe, Joseph MD; Barton, Erik MD, MS; Bernhisel, Kurt MD; Bess, Elizabeth BS; Madsen, Troy MD

Journal of the American Academy of PAs: August 2011 - Volume 24 - Issue 8 - p 31–37

Objective: An emergency department observation unit (EDOU) opened in April 2006 staffed by physician assistants (PAs) and nurse practitioners (NPs). This study describes the complexity and outcomes of the EDOU patients to determine the effectiveness of staffing by PAs.

Methods: A retrospective chart review was performed of chest pain and trauma patients in the EDOU from April 2006 through May 2007. Patient characteristics, length of stay (LOS), and admission rates were recorded. Adverse events were monitored, and trauma patients were followed for 30 days to evaluate for missed injuries.

Results: 531 chest pain patients and 364 trauma patients were admitted to the EDOU during the study period. Average chest pain patient LOS was 14 hours and 32 minutes, and 12.2% of patients were admitted from the EDOU to an inpatient unit. For trauma patients, average LOS was 12 hours and 46 minutes, and 11.5% of patients were admitted to an inpatient unit. There were no deaths, intubations, or loss of vital signs. In 30-day follow-up, there were no significant missed injuries among trauma patients.

Conclusion: PAs effectively cared for patients of moderate complexity in the two largest groups of utilizers of the EDOU.

The authors are from the university of Utah Health Sciences Center emergency department, salt Lake City, Utah. Kelly Sherwood and Steven Sugerman are PAs; Philip Bossart, Erik Barton, Kurt Bernhisel, and Troy Madsen are attending physicians; Joseph Bledsoe is an attending physician and research fellow; and Elizabeth Bess is the emergency medicine research coordinator. The authors have indicated no relationships to disclose relating to the content of this article.

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Emergency department observation units (EDOU) have a long history of being utilized to care for emergency department (ED) patients who require more than 4 to 6 hours of ED treatment.1 Many studies have described the success of these units in caring for ED patients.2–8 The use of physician assistants (PAs) in the ED has also been studied,9–11 and the successful use of PAs in other settings has been well-evaluated.12–19 In addition, a trend of staffing EDs with PAs has been documented.20 However, staffing of EDOUs has not been described previously. The University of Utah Emergency Department opened an EDOU in April 2006 that is staffed predominately by full-time PAs and two part-time nurse practitioners (NPs).

The University of Utah Medical Center is one of two adult level I trauma centers located in metropolitan Salt Lake City, Utah. The hospital serves as a tertiary care center for Utah and parts of Nevada, Idaho, and Wyoming. It has 425 beds, and the ED sees approximately 39,000 patients every year. The main function of the 10-bed EDOU is to monitor patients who do not clearly meet criteria for admission to the hospital yet who would benefit from a period of observation or continued treatment intervention prior to final disposition.

This descriptive analysis and retrospective chart review sought to describe the operation of the EDOU and investigate which types of patients were under the care of PAs in the EDOU. The goal was to better understand both the numbers of patients and their medical complexity and risk factors. Second, the outcomes of these patients were evaluated to determine whether patients of this medical complexity can be safely evaluated in an EDOU primarily under the care of PAs.

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The EDOU presents an option for ongoing care of emergency department patients who may require extended evaluation and treatment but do not meet specific criteria for admission. These patients may be awaiting the results of testing, may require IV antibiotics or serial laboratory tests, or would benefit from a period of observation to ensure clinical improvement.

From its inception in April 2006, the 10-bed EDOU was staffed by physician assistants. As the hours of coverage in the EDOU have increased, staffing has increased to eight full-time PAs and two part-time NPs covering shifts in the EDOU as well as in the ED. This staffing allows for rounding on patients, reexamination, evaluation of overnight laboratory or radiographic studies, direction of any further evaluation, coordination with consulting services, and ultimately disposition. PAs currently staff the EDOU for 21 hours per day, from 7 am until 4 am. Outside of these hours, attending physicians in the ED are available for consultation by nurses or for patient care decisions.

The EDOU treats a wide variety of patients and is largely protocol driven. The EDOU utilizes 19 different protocols that provide guidelines and ordersets specific to the diagnosis or chief complaint for admission to the EDOU (Table 1).



Initial EDOU orders are written by the attending ED physician prior to transfer to the EDOU. Once the patient is in the EDOU, care is assumed by the PA. This includes, but is not limited to, reexamination, following up on all pending results, ordering medications and additional tests as appropriate, and coordinating with nursing, consultants, or ancillary services. The PA also assumes responsibility for admitting the patient to the hospital for any decline in the patient’s condition as well as for the morning disposition decision. Attending ED physicians are available at all times for consultation as needed.

The maximum length of stay in the EDOU is 23 hours. This time period allows for multiple interventions such as serial examinations, laboratory tests, radiographic studies, consultations with specialty services, case management, or physical therapy.

In addition to the above protocol-driven criteria, the EDOU may also be used to care for patients who have been admitted to the hospital but must wait for a bed to become available. Traditionally, these patients would remain in the ED, making it more difficult to care for new ED patients. Having the EDOU PA and nursing staff provide care for the patient instead reduces ED overcrowding with stable patients for whom disposition has been determined.

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A retrospective chart review was performed of patients admitted to the University of Utah EDOU over the first 14 months of its operation: April 2006 through May 2007. The authors looked specifically for adverse events among patients and followed trauma patients for 30 days to evaluate for missed injuries as markers to determine the effectiveness of care provided by PAs. The greatest number of patients were found to fall under the chest pain and trauma protocols. In evaluating the safety of patient care in the EDOU, the authors focused specifically on these two groups. Chest pain and trauma patients were the two largest groups of patients in the observation unit, and focusing on these two groups allowed use of standard definitions for risk factors, patient characteristics, and outcomes, thus ensuring a certain amount of uniformity in the data abstraction and comparison.

Chest pain and trauma patients are two groups of patients that have been fairly well-studied, particularly in the emergency medicine literature, and thus it was possible to employ standard definitions to describe the complexity of the patients seen as well as evaluate for any adverse outcomes among these groups. Second, these two groups were considered most generalizable to other emergency departments. EDOUs typically utilize a protocol for chest pain patients. While a protocol may not be as widely accepted for trauma patients as for chest pain patients, EDs may also choose to employ such a protocol given the large numbers of patients that would be admitted under it. This was the reason for inclusion of this group of patients.

Admission rates and length of stay were recorded for these patients. Additionally, the authors looked specifically for adverse events and followed trauma patients for 30 days to evaluate for missed injuries. Chart review was performed by trained medical students. All patients placed in the EDOU were identified through hospital billing charges for ED observation. One of the principal investigators (TM) met with the medical students at the inception of the study and communicated monthly thereafter to resolve any discrepancies in data entry. Students used predefined criteria and definitions for data abstraction, as well as a standardized data abstraction form. Variables were based on patient self-reporting to the physician at the time of interview and physician documentation on the medical record. Renal insufficiency was documented based on a serum creatinine of 1.5 mg/dL or greater at the time of the ED visit. A history of coronary artery disease (CAD) was defined as a patient self-reported history of MI, stent placement, or coronary artery bypass graft (CABG). Follow-up on trauma patients was performed by one of the principal investigators (TM). Results are presented using descriptive statistics (SPSS v. 16.0).

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A total of 2,297 patients were placed in the EDOU during the 14-month study period, for an average of 5.5 patients in the EDOU per day (range, 0-10 patients). Chest pain admissions averaged 1.2 patients/day (range, 0-7 patients), while trauma admissions averaged 0.9 patients/day (range, 0-8 patients). The two largest groups utilizing the EDOU were patients on the chest pain and trauma protocols: 524 chest pain patients and 364 trauma patients were admitted to the EDOU during this time. These two groups of patients represented 38.7% of all EDOU admissions during the study period.

Of chest pain patients, 52.3% were male; the average age was 55.8 years (range, 22-91 years; standard deviation [SD], 14.8 years), with geriatric patients (defined as those 65 years or older) comprising 24.8% of the total. Of trauma patients, 66% were male; the average age was 35.4 years (range 16-88 years, SD, 17.3 years).

Chest pain patients comprised the greatest number of admissions to the EDOU. Criteria excluding patients from the EDOU chest pain protocol are listed in Table 2 and included an elevated troponin level in the ED, ongoing chest pain of suspected cardiac etiology, and significant ECG changes. The characteristics of chest pain patients were evaluated to describe the complexity of patients under the care of the PAs staffing the EDOU. Of patients admitted under the chest pain protocol, 23.5% had a history of CAD, which classified them as intermediate-risk patients; 58.8% reported a history of hypertension; 7.9% had congestive heart failure; 49% had a family history of CAD; 22.6% had diabetes; and 10.4% had renal dysfunction.



Chest pain patients underwent biomarker rule-out with serial troponin levels followed by provocative testing and/or cardiology consultation. Decision to admit the patient to an inpatient unit or to discharge home for outpatient follow-up was made based on the results of testing and by the consulting cardiologist in cooperation with the PA in the EDOU. No deaths, intubations, or adverse events occurred among chest pain patients. Average length of stay for EDOU patients under the chest pain protocol was 14 hours, 32 minutes, and 12.2% of patients were admitted from the EDOU to an inpatient unit.

Trauma patients were the second largest group of patients admitted to the EDOU. Of patients placed in the EDOU on the trauma protocol, 84.6% had initially presented to the ED as trauma II activations. Trauma I activations comprised 15.4% of EDOU admissions. Trauma activation criteria are listed in Table 3, and exclusion criteria for this group are outlined in Table 4. The greatest number of admissions were secondary to a motor vehicle collision (MVC), followed by fall and ski and snowboard injuries. Figure 1 further characterizes admission by mechanism of injury.







The average length of stay for trauma patients was 12 hours, 46 minutes, and 11% of patients were admitted to an inpatient unit. No deaths, intubations, or adverse events occurred among trauma patients. During the 30 days following discharge from the EDOU, 17 patients returned to the ED (4.7%). Among this group, only one patient was found to have an injury not previously diagnosed during the EDOU stay. This consisted of a retained piece of glass in a laceration. No other missed injuries were identified, and no patients were admitted to the hospital upon return visit to the ED.

Some seasonal variation in admission rates was found, but this may have been affected by the comfort level of consulting services, changes in hospital policy, and other factors, rather than the season. A bump in winter trauma admissions was seen, however, which is explained by the large number of ski, snowboard, and snowmobile injuries evaluated and treated in this part of Utah. The seasonal numbers were as follows: for chest pain patients, 119 for June through August, 132 for September through November, 102 for December through February, and 146 for March through May; for trauma patients, 82 for June through August, 89 for September through November, 103 for December through February, and 82 for March through May.

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This retrospective chart review investigated which types of patients were under the care of PAs in the EDOU to better understand both the numbers of patients under their care as well as the medical complexity and risk factors of these patients and their outcomes. Most of those cared for by PAs in the EDOU were chest pain patients with a history of coronary disease and trauma patients who presented as trauma activations. In most hospitals, these patients would be admitted to an inpatient service under the care of a specialist, either a cardiologist or trauma surgeon. This study has shown that the patients cared for by PAs are medically complex.

“Results from this retrospective chart review support the safe, effective care of EDOU patients by physician assistants.”

Another key finding was that the admission rates for these patients fell within generally accepted guidelines for observation unit “failure” rates, with an inpatient admission rate from the EDOU of less than 15%. This indicates that patient selection for the EDOU by the ED physicians and PAs was appropriate. Additionally, the absence of significant adverse outcomes and missed injuries among these complex patients attests to the ability of PAs to provide safe and effective EDOU care.

This retrospective chart review, then, describes a viable staffing model for an EDOU utilizing PAs. The providers cared for various, complex patients and did so with outcomes appropriate for an EDOU. The providers cared for an average of 5.5 patients per day representing patients on 19 different care protocols. Among the protocols most utilized in the EDOU, the chest pain and trauma protocols, these patients represented a large percentage of moderate-risk chest pain and trauma activation patients. These were patients who, at other institutions, would likely be admitted to an inpatient unit under the care of a specialist. This study has demonstrated that these patients were treated by PAs in an EDOU setting without significant adverse outcomes or missed injuries.

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A retrospective chart review has its inherent limitations, such as missing data and inconsistent or erroneous documentation. It is possible that missed injuries or adverse outcomes were not discovered due to lack of documentation.

This chart review focused primarily on chest pain and trauma patients rather than all patients admitted to the EDOU during the study period. While these two groups represented more than one-third of patients admitted during the study period, patients from other protocols may have experienced adverse events that were missed in the chart review.

Results from this retrospective chart review encouragingly support the safe, effective care of EDOU patients by PAs. However, further research, including studies comparing EDOU PA staffing to other EDOU staffing models, would provide additional information on the efficacy of PAs in EDOUs.

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In this study, PAs managed moderately complex conditions in the two largest groups of EDOU utilizers: chest pain and trauma patients. In the patients studied, no adverse events or missed injuries occurred during the study period. Based on these favorable results, EDOU directors may wish to consider physician assistants as part of a viable and adequate staffing model.

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