Transfers and anesthesia-related postoperative outcomes after 3361 same-day cancer surgeries at a freestanding surgery center: An observational retrospective study

Abstract

Background and Objectives:

Expanding outpatient surgery to the increasing number of procedures and patient populations warrants continuous evaluation of postoperative outcomes to ensure the best care and safety. We describe adverse post-operative outcomes and transfer rates related to anesthesia in a large sample of patients who underwent same-day cancer surgery at a freestanding ambulatory surgery center.

Methods:

Between January 2017 and June 2021, 3361 cancer surgeries, including breast and plastic, head and neck, gynecology, and urology, were performed. The surgeries were indicated for diagnosis, staging, and/or treatment. We report the incidence of transfers and adverse postoperative outcomes related to anesthesia.

Results:

Breast and plastic surgeries were the most common (1771, 53%), followed by urology (1052, 31%), gynecology (410, 12%), and head and neck surgeries (128, 4%). Based on patients’ first procedure, comorbidity levels were highest for urology (75% American Society of Anesthesiologists physical status score 3, 1.7% score 4) and lowest for breast surgeries (31% score 3, 0.2% score 4). Most gynecology surgeries used general anesthesia (97.6%), whereas breast surgeries used the least (38%). A total of seven patients (0.2%; 95% CI: 0.08%−0.4%) were immediately transferred to an outside hospital; four due to anesthesia-related reasons. Only 7 (0.2%) patients needed additional postoperative care related to anesthesia-related adverse events, specifically cardiac events (4), difficult intubations (2), desaturation (1), and agitation, nausea, and headache (1).

Conclusions:

The incidence of anesthesia-related adverse postoperative outcomes is low in cancer patients undergoing outpatient surgeries at our freestanding ambulatory surgery center. This suggests that carefully selected cancer patients, including patients with metastatic cancer, can undergo anesthesia for same-day surgery, making cancer care accessible locally and reducing stress associated with travel for treatment. More research investigating complication rates related to surgery and to cancer disease trajectory are needed to establish a complete evaluation of safety for outpatient cancer surgery.

1 |. INTRODUCTION

The recent expansion of ambulatory surgery provides improved patient-centered care by bringing care closer to home and reducing costs without compromising safety.¹ However, the trend to move a wider range of complex procedures and patient populations to ambulatory settings calls for continuous evaluation of perioperative outcomes, including anesthesia-related complications. This is especially vital to expanding care to freestanding surgery centers, which lack overnight stays and other facets of care available in hospital affiliated ambulatory surgery centers or inpatient settings.

Cancer patients represent a high-risk group for clinical complications when undergoing ambulatory procedures.^2,3 Patients with disseminated cancer, in particular, have an increased risk of morbidity and readmission after ambulatory surgery.^2,3 The incidence of perioperative events related to outpatient surgery, including anesthesia-related factors, are important to consider, especially when evaluating patients who are at high-risk for postoperative complications.⁴ Incidence of morbidity and mortality after outpatient surgery have been reported in all-risk and some high-risk patient populations. However, comparable analyses based on a large sample size of cancer patients are limited. It is important to evaluate the safety profile of anesthesia for outpatient surgery in this population, given their medical complexity.

Memorial Sloan Kettering (MSK) Cancer Center Monmouth is a freestanding ambulatory cancer facility providing treatment, including surgery and nonoperating room anesthesia procedures in the perioperative platform, for a high volume of patients since January 2017. MSK Monmouth is the only suburban regional site, effectively expanding the provision of care and increasing access for oncologic patients closer to home in New Jersey.

Patient selection guidelines vary for ambulatory surgery based on the surgical setting and the interplay between the surgical procedure, patient comorbidities, and anesthetic requirements.⁴ Some facilities may have absolute exclusion criteria, including high American Society of Anesthesiologists (ASA) physical status score, age, body mass index (BMI), or obstructive sleep apnea status.^5–8 Expansion of ambulatory surgery to patients with severe comorbidities, including patients with ASA physical status score 3 and 4, is an ongoing phenomenon.⁹ The ASA physical status score is commonly used to characterize the patient’s overall health and to assess perioperative risk and has been shown to accurately predict perioperative complications, including morbidity, mortality, and length of stay.^10–13

The objective of this study was to describe and report the incidence of all-cause transfers as well as adverse postoperative outcomes related to anesthesia for patients undergoing surgery at MSK Monmouth.

2 |. MATERIALS AND METHODS

2.1 |. Patient population and study setting

After approval from the MSK Institutional Review Board (IRB), we obtained procedure and outcomes data for patients undergoing ambulatory surgery at MSK Monmouth from the center’s opening on January 5, 2017, to the closing of the study database on June 10, 2021. During this timeframe, we identified 3361 procedures with anesthesia team services performed in patients 18 years of age or older among 2496 unique patients for analysis. The requirement for written informed consent was waived by the IRB.

MSK Monmouth has one perioperative platform with two operating rooms and an integrated angiography-computerized tomography interventional radiology suite. Outpatient surgical procedures include breast and plastic surgery, head and neck, gynecology, and urology. Nonoperating room anesthesia procedures (e.g., interventional radiology, interventional pulmonology and thoracic, pain, bone marrow medicine, and gastroenterology), which are incorporated within the perioperative platform, and local procedures performed without anesthesia personnel (e.g., superficial biopsies) were not included. Other outpatient surgeries, including colorectal, gastric mixed tumor, and orthopedics, were excluded from the analysis due to low case volume.

Patient selection is an interactive process among the healthcare team specific to the service, taking into consideration the surgical procedure, patient comorbidities, and anesthetic requirements. Patient exclusion is determined on a case-by-case basis. Certain serious medical comorbidities and other criteria, such as risk factors for a potential difficult airway, BMI >45 kg/m², recent heart attack or stroke, presence of a permanent pacemaker or an automatic implantable cardioverter-defibrillator, and end-stage renal disease on dialysis, serve as flags to the anesthesia team for further assessment of patient eligibility. The perioperative team, including the surgeons, surgical physician assistants, consulting physicians, presurgical testing nurse practitioners, and anesthesia team, communicate any concerns about patient eligibility. The anesthesiologist serves as the main gatekeeper for determining final eligibility. Further details on the most common surgeries performed and patient selection strategies are included in the Supporting Information Material.

Routine clinical care data, symptom care clinic (SCC) visits, urgent care clinic (UCC) visits, and hospital admissions data were queried from the MSK institutional database. MSK Monmouth has an on-site SCC, which is similar to an UCC, but with a limited scope of services and often by appointment only. As it is most likely that patients visited an outside hospital for care, care coordination nursing notes within 30 days postprocedure were queried and a keyword search was performed to identify potential postoperative visits to outside hospitals. We searched for the following terms: ED, ER, emergency, UCC, urgent, SCC, symptom care, ADM, admit, admission, and hospital. A manual retrospective chart review was conducted by two research team members, including a practicing anesthesiologist. The two reviewers evaluated the flagged adverse outcomes to confirm if the events occurred and to review if the events were anesthesia-related. Only anesthesia-related reasons for adverse postoperative outcomes were included for the analysis. Anesthesia was attributed as the reason of the outcome whenever probable. If there were multiple types of adverse events related to one case (e.g., urgent care visit and admission), then each event was evaluated separately.

Adverse postoperative outcomes included in-procedure room cancellations, immediate outside hospital transfers, emergency department visits within 7 days, and unanticipated hospital admissions within 1 and 7 days.¹⁴ Mortality was evaluated at 3 days to assess the immediate impact of complications from anesthesia. Regardless of receipt of ambulatory procedures, unplanned hospitalizations, and acute care visits are common in cancer patients and may be an expected part of their disease trajectory.^15,16 Therefore, we focused solely on anesthesia-related adverse postoperative outcomes. In line with what has been reported in the literature,¹⁷ scheduled visits or hospital admissions related to cancer care in the postoperative period were not counted as adverse postoperative outcomes (n = 1).

2.2 |. Statistical analysis

Descriptive and incidence data were generated by estimating the rate of adverse postoperative outcomes in patients undergoing procedures at MSK Monmouth. When summarizing the post-anesthesia care unit (PACU) length of stay, we excluded patients who were transferred to another hospital. We also report on the incidence of each adverse postoperative outcome: in-procedure room cancellations, transfers from the PACU, and the following events if they were related to anesthesia: urgent care (SCC or UCC) visits within 7 days, emergency department visits within 7 days, and hospital admissions within 1, 3, and 7 days, and mortality within 30 days. Descriptive statistics were calculated using Stata 17 (StataCorp.).

3 |. RESULTS

Patient characteristics by service are shown in Table 1. Based on the patients’ first procedure at MSK Monmouth, comorbidity (ASA physical status score 3) was highest for urology (75%) and lowest for breast and plastic surgery (31%); 9 (1.7%) patients who received urology procedures had ASA physical status score 4. Eight hundred sixty-five patients (26%; 95% CI: 24%−27%) returned to MSK Monmouth for multiple procedures within the reported period (between 2 and 16 procedures per patient).

TABLE 1.

Patient characteristics based on first procedure.

Characteristic	Breast/plastics (n = 1522)	Gynecology (n = 320)	Head & neck (n = 116)	Urology (n = 538)
Age	58 (50−68)	55 (44−65)	64 (57−71)	69 (62−76)
Male	10 (0.7%)	0 (0%)	80 (69%)	375 (70%)
Race
Asian	107 (7.0%)	17 (5.3%)	5 (4.3%)	13 (2.4%)
Black or African American	54 (3.5%)	9 (2.8%)	3 (2.6%)	17 (3.2%)
Other	32 (2.1%)	6 (1.9%)	2 (1.7%)	11 (2.0%)
Unknown	83 (5.5%)	15 (4.7%)	4 (3.4%)	26 (4.8%)
White	1246 (82%)	273 (85%)	102 (88%)	471 (88%)
Ethnicity
Hispanic or Latino	70 (4.6%)	15 (4.7%)	3 (2.6%)	23 (4.3%)
Unknown	85 (5.6%)	23 (7.2%)	5 (4.3%)	37 (6.9%)
Body mass index	27 (24−32)	27 (23−32)	27 (23−30)	28 (24−32)
ASA
3	470 (31%)	140 (44%)	78 (67%)	406 (75%)
4	3 (0.2%)	0 (0%)	0 (0%)	9 (1.7%)

Note: Data are presented as median (quartiles) and frequency (%).

Procedure characteristics by service are shown in Table 2. The most frequent surgical procedures involved breast and plastics (1771; 53%) and urology (1052; 31%) services. Median operative time was shortest for gynecology (10 min) and longest for breast and plastics (36 min). More than half of all procedures (63%) employed general anesthesia. The breast service employed the most monitored anesthesia care (62%), of which, 5% were converted to general anesthesia. Median PACU length of stay was shortest for head and neck (87 min) and longest for urology (113 min) surgeries.

TABLE 2.

Procedure characteristics.

Characteristic	Breast/plastics (n = 1771)	Gynecology (n = 410)	Head & neck (n = 128)	Urology (n = 1052)
Procedure duration (min)	36 (24−50)	10 (6−17)	20 (13−34)	22 (14−36)
Anesthesia duration (min)	64 (50−79)	43 (37−52)	62 (48−76)	60 (49−76)
MAC anesthesia	1102 (62%)	10 (2.4%)	7 (5.5%)	114 (11%)
Anesthesia conversion	89 (5.0%)	1 (0.2%)	0 (0%)	2 (0.2%)
Length of stay in PACU (min)a	96 (79−120)	95 (76−121)	87 (72−112)	113 (89−146)

Note: Data are presented as median (quartiles) and frequency (%).

Abbreviation: PACU, post-anesthesia care unit.

^aPatients who were transferred from PACU were excluded.

The rates of anesthesia-related adverse outcomes were low and are displayed by service in Table 3. Out of seven immediate outside hospital transfers among all procedures, four were related to anesthesia (0.1%). The other reasons for transfers included two allergic reactions and one pleural effusion. All four anesthesia-related transfers were followed by an emergency department visit, and three resulted in an unanticipated hospital admission. Three of those events were due to cardiac reasons, and one was due to patient agitation, nausea, and headache. The cardiac events included postoperative chest pain, ST depressions noted post-induction and before surgical incision, and postoperative hypotension in the PACU. Three cases were aborted due to anesthesia-related complications: two involved difficult intubations due to a history of radiation therapy, and one involved a desaturation. There were no anesthesia-related UCC or SCC visits within 7 days. The rate of anesthesia-related adverse postoperative outcomes was highest in head and neck surgery (0.8%), and there were no adverse events in breast surgery. There were no deaths related to anesthesia within 30 postoperative days and no anesthesia-related adverse postoperative outcomes after postoperative day 1.

TABLE 3.

Transfers and adverse postoperative outcomes related to anesthesia.

Adverse outcome	Breast/plastics (n = 1771)	Gynecology (n = 410)	Head & neck (n = 128)	Urology (n = 1052)
In-room cancellation	0 (0%)	0 (0%)	1 (0.8%)	4 (0.4%)
Immediate transfer to hospital from PACU	0 (0%)	1 (0.2%)	1 (0.8%)	2 (0.2%)
Urgent or symptom care clinic visits within 7 days	0 (0%)	0 (0%)	0 (0%)	0 (0%)
Emergency department visits within 7 days	0 (0%)	1 (0.2%)	1 (0.8%)	2 (0.2%)
Admissions within 7 days	0 (0%)	0 (0%)	1 (0.8%)	2 (0.2%)

Note: Data are presented as n (%) for each procedure.

Abbreviation: PACU, post-anesthesia care unit.

4 |. DISCUSSION

The incidence of anesthesia-related adverse postoperative outcomes in cancer patients who underwent anesthesia at our freestanding ambulatory surgery center is low. The seven complications were related to difficult intubations and cardiac reasons and were safely addressed within our institution and in the area hospitals.

To our knowledge, only one study at a different MSK free-standing ambulatory surgery center, the Josie Robertson Surgery Center (JRSC), has examined adverse postoperative outcomes in a large sample of cancer patients undergoing ambulatory procedures.¹⁸ These centers differ in several ways, including the case mix and integration of nonoperating room anesthesia into the perioperative platform. JRSC accommodates more complex cases, allowing a single overnight stay. Located six blocks from the main hospital, JRSC can conveniently escalate care, whereas MSK Monmouth is a considerable distance away from the main hospital in New York City and 15−20 min away from the nearest local hospital. MSK Monmouth houses an SCC to treat minor issues but lacks overnight capabilities. Transfers or hospitalizations typically occur at area hospitals not affiliated with our institution. Our overall immediate hospital transfer rate (0.1%) was similar to their rate (0.3%) for same-day surgeries. Patients at both centers have similar comorbidity burden; 33% had ASA physical status 3 or 4 at the time of first surgery at MSK Monmouth compared to 35%−38% at JRSC.¹⁹ Therefore, a similar incidence of transfers is conceivable. Since we focused on reviewing anesthesia-related adverse postoperative outcomes, comparing all-cause rates for adverse events is outside the scope of this analysis.

Rates of anesthesia-related adverse postoperative outcomes are higher for higher-risk and older patients.^2,14 In our study, six out of the seven anesthesia-related events occurred in urology and in head and neck surgery, services with the highest comorbidity burden (76.7% and 67% patients with ASA physical status score 3 or 4 at first visit at MSK Monmouth, respectively); five patients who experienced an anesthesia-related event were over 70 years old. Therefore, we reaffirm the utility of gauging patient age and physical status in preoperative evaluation for outpatient surgery. There is variability in the selection criteria and comfort level in caring for cancer patients in ambulatory settings.²⁰ Cancer patients are reported to have a reasonably predictable decline in physical health, often over a short period of time.²¹ Performance status, including functional ability and metabolic equivalents, is an important consideration during the perioperative timeframe.²² Common consequences of cancer, including weight loss, cachexia, anemia, cancer-associated thrombosis, and chemotherapy-related toxicities, play a significant role in comorbidity burden, and events related to disease progression may occur alongside postoperative outcomes related to anesthesia.²²

Unanticipated hospital admission rates following ambulatory surgery published within the past 15 years range from 0.11% to 2.89%,^{2,3,17,23–25} reflecting different procedure types, patient populations, and mechanisms for characterizing and reporting outcomes. Over time, there has been an increase in patient age and medical complexity and an expansion in the range of procedures performed in ambulatory surgery centers.^5,6 Higher unanticipated hospital admission rates have been reported among specific higher-risk patient populations (e.g., older patients) and riskier procedure types (e.g., cardiovascular and urinary procedures).²⁶ In our oncologic population, anesthesia-related same-day postoperative emergency department visit rate (0.12%) and unanticipated hospital admission rate (0.09%) were low. However, our rates did not include other reasons for admission, such as surgical complications. Immediate unanticipated hospital admissions reported in the literature are most attributed to procedure-related adverse postoperative outcomes, while anesthesia- and medical-related adverse postoperative outcomes are less common.^17,23,27,28

Mortality after surgery and treatment varies by cancer type, disease progression, and other clinical and nonclinical factors.^29–31 Three-day mortality rates reported in the literature after outpatient surgery were 0.04% and 0.01%.^2,25 We report no anesthesia-related deaths within 30 days.

Notably, there were no anesthesia-related complications following the day of surgery. The low rates of immediate anesthesia-related adverse postoperative outcomes and no anesthesia-related adverse events in the later postoperative window suggest appropriate prioritizing of the preoperative evaluation of patient characteristics (e.g., ASA physical status score, cancer stage) and surgical factors (e.g., extent of surgery) and optimization for anesthesia safety. Our rates of anesthesia-related adverse postoperative outcomes are lower than reported in studies comprising populations of “high-risk” patients with ASA physical status score 3 and 4 and patients ≥65 years.^2,14 Although cancer patients have an added comorbidity burden, our center provides care for a high volume of patients undergoing a wide range of mostly minor procedures and implements patient selection strategies to prevent escalation of care, including transfers to local outside hospitals. More reports on complication rates due to all reasons after outpatient surgery in the oncologic population are needed.

The completeness of the data is limited by the nature of the retrospective chart review, which included using standard outcomes as well as keyword searches of nursing notes. This may have underestimated the true number of adverse postoperative outcomes which occurred at outside hospitals unaffiliated with MSK. Our use of ASA physical status score to assess perioperative risk^10–13 might also be a limitation in the oncologic population. The same ASA physical status score may not elucidate meaningful clinical differences between a cancer patient and a patient with a different systemic disease, such as heart failure. Future studies should examine specific aspects of disease severity and functional status, including cachexia,^32,33 and how these affect postoperative outcomes for high-risk oncologic versus non-oncologic patients undergoing ambulatory surgery.

5 |. CONCLUSIONS

The high-risk status of cancer patients should not necessarily preclude them from having outpatient procedures. These patients can benefit from making crucial cancer care available locally, especially considering the disease trajectory of advanced cancer often necessitating multiple healthcare visits. This study demonstrates that oncologic patients undergoing anesthesia for outpatient procedures can be safely cared for with minimal anesthesia-related adverse outcomes, supporting the expansion of the multiservice same-day discharge care model to carefully selected higher risk cancer patients. Future analyses should further elucidate the role that cancer plays in the comorbidity burden.

DATA AVAILABILITY STATEMENT

Research data are not shared.