Establishing outpatient cholecystectomy as a hospital routine
Andrus J. Voitk, MD, MSc
Canadian Journal of Surgery 1997;40(4):284-288
[résumé]
From the Department of Surgery, The Salvation Army Scarborough Grace Hospital, Scarborough, Ont.
Presented in part at the symposium Ambulatory Surgery: Principles, Practice, Pitfalls at the annual meeting of the Canadian Association of General Surgeons, Halifax, NS, Sept. 27, 1996
Accepted for publication Feb. 13, 1997
Correspondence to: Dr. Andrus J. Voitk, Surgeon-in-Chief, Ste. 1840, The Salvation Army Scarborough Grace Hospital, 3030 Birchmount Rd., Scarborough ON M1W 3W3; tel/fax 416 495-7397; minaise@pathcom.com
© 1997 Canadian Medical Association (text and abstract/résumé)
See also p.259
Contents
Abstract
Objectives: To determine the rate of outpatient cholecystectomies done voluntarily by surgeons and to identify any "correctable" factors leading to hospital admission, also to reassess the outpatient cholecystectomy rate after correcting the identified factors.
Design: A prospective analysis.
Setting: A 256-bed non-teaching acute-care community hospital on the outskirts of a major urban centre, served by 4 general surgeons.
Patients: All 515 patients booked for elective cholecystectomy at the hospital between Apr. 1, 1994, and Mar. 31, 1996, inclusive.
Intervention: Elective outpatient cholecystectomy.
Main outcome measure: A successful procedure without compromise of safety.
Results: In the preliminary study, outpatient cholecystectomy was done in 75% of the patients. Variations in individual surgical practice, preoperative patient selection and inappropriate day surgery facilities were thought to be correctable factors leading to admission. After correction of the these factors (follow-up study), the rate of outpatient cholecystectomy rose to 95% (p < 0.001). Variations in individual surgical practice disappeared, and no patient required processing through inappropriate day surgery facilities. No patient suffered untoward effects from outpatient management.
Conclusions: Outpatient cholecystectomy is a safe hospital routine for all elective procedures without selection. Voluntary acceptance of this routine leads to an initial 75% outpatient rate. Identifying and correcting modifiable factors led to a significant increase in the institutional outpatient rate, comparable to reported individual rates.
Résumé
Objectifs : Déterminer le taux de cholécystectomies pratiquées en service externe et effectuées volontairement par des chirurgiens, définir tout facteur «correctible» qui entraîne l'hospitalisation et réévaluer le taux de cholécystectomies pratiquées en service externe après correction des facteurs définis.
Conception : Analyse prospective.
Contexte : Hôpital communautaire de soins actifs sans enseignement de 256 lits, situé en périphérie d'une grande agglomération urbaine, desservi par quatre chirurgiens généraux.
Patients : Les 515 patients qui devaient subir une cholécystectomie élective à l'hôpital entre le 1er avril 1994 et le 31 mars 1996 inclusivement.
Intervention : Cholécystectomie élective pratiquée en service externe.
Principale mesure des résultats : Intervention réussie sans compromettre la sécurité.
Résultats : L'étude préliminaire a indiqué qu'on a pratiqué une cholécystectomie en service externe chez 75 % des patients. Les variations au niveau de la pratique chirurgicale individuelle, la sélection des patients avant l'intervention et des installations insuffisantes de chirurgie ont été considérées comme des facteurs correctibles entraînant l'hospitalisation. Après correction de ces facteurs (étude de suivi), le taux de cholécystectomies pratiquées en service externe est passé à 95 % (p < 0,001). Les variations au niveau de la pratique chirurgicale individuelle sont disparues et aucun patient n'a dû être traité dans des installations de chirurgie de jour insuffisantes. Aucun patient n'a subi d'effet indésirable après avoir été traité en service externe.
Conclusions : La cholécystectomie pratiquée en service externe est une intervention hospitalière routinière dans le cas de toutes les interventions électives sans sélection. L'acceptation volontaire de cette routine entraîne un taux initial de traitement en service externe de 75 %. La définition et la correction des facteurs modifiables ont entraîné une augmentation significative du taux d'interventions pratiquées en service externe de l'établissement, comparable à celle des taux individuels signalés.
Encouraged by reports of 90% individual outpatient cholecystectomy rates,13 staff in the Division of General Surgery at the Salvation Army Scarborough Grace Hospital voluntarily decided to make outpatient cholecystectomy a hospital routine. This 2-part study reports on this experience. A preliminary study identified correctable factors leading to admission. A follow-up study determined whether correction of these factors resulted in an increased voluntary outpatient rate.
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Methods
The Salvation Army Scarborough Grace Hospital is a 256-bed non-teaching acute-care community hospital on the outskirts of a major urban centre. The hospital is served by 4 general surgeons. In the office, the surgeon explained to the patient the nature of the illness and the proposed procedure. Patients were advised that the laparoscopic approach would make surgery possible on an outpatient basis but that they could be admitted if medical needs dictated. In the hospital's preadmission clinic, all patients received confirmation of the outpatient nature of their upcoming experience by direct teaching and an explanatory video. Patients arrived an hour before the procedure at the day surgery area, where the nurses reinforced the outpatient aspect of the treatment, and patients returned to the day surgery area from the recovery room.
The American Society of Anesthesiologists' (ASA) classification of physical status4 was recorded preoperatively by the anesthetist. After intravenous induction of anesthesia and muscle relaxation the patient was intu-bated and general inhalational anesthesia given; occasionally the anesthetic was delivered through a laryngeal mask. The anesthetists (5 regular and 4 casual) used their own routine. No special antinausea technique was used and no antinausea agents were given routinely. Meperidine analgesia was offered parenterally in the Post Anesthetic Care Unit as needed. In the day surgery area, 1 or 2 tablets of 300 mg acetaminophen with 30 mg codeine were prescribed for pain every 4 hours as needed and a similar prescription was given at the time of discharge.
The operative technique was similar to that reported previously,1 with 2 minor variations: 3 surgeons preferred the Veress needle to the Hasson cannula for initial pneumoperitoneum, and 1 surgeon routinely prescribed low-dose heparin and intravenous cefazolin preoperatively.
Two months were allowed for all surgeons to adjust to the new practice, and then all elective cholecystectomies done at the Salvation Army Scarborough Grace Hospital from Apr. 1, 1994, to Mar. 31, 1996, were used in the study. Patients admitted for emergency cholecystectomy as well as those having other major procedures (e.g., bile duct exploration, Nissen fundoplication, bowel resection) were excluded. Those having operative cholan-giography, incidental appendectomy, liver or lymph-node biopsy, umbilical and inguinal hernia repair and saphenec-tomy were accepted.
Surgeons were not actively monitored, although information was culled prospectively from each patient's chart during hospital treatment. Toward the end of the first year, results were analysed and correctable causes leading to hospital admission identified. This first year, devoted to identifying problems, constitutes our preliminary study. Individual results were compared and discussed by the surgeons during educational sessions. Because preselection of higher risk patients for admission seemed arbitrary and of no apparent benefit, this practice was abandoned. At the same time, the hospital administration ensured adequate and appropriate day surgery facilities to accommodate the increased load, so that unlimited outpatient cases could be booked at any time during elective hours. Our experience in the second year, after problems were corrected, constitutes our follow-up study.
Probability calculations were done using the chi2 and Student's t-tests, and differences were deemed significant if the probability value for chance occurrence was less than 5%.
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Patients
Two hundred and forty-two elective cholecystectomies were done in the first year (preliminary study) and 273 in the second (follow-up study). The patients (118 men [23%]) ranged in age between 19 and 88 years (average 49 years). Fifty-seven patients were over 70 years old and 11 over 80 years. The preoperative ASA classification was as follows: 223 class 1, 246 class 2, 44 class 3 and 2 class 4. Changes indicative of acute cholecystitis were present in 45 patients. These characteristics were similar for both years.
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Results
Preliminary study
Of the 242 elective cholecystectomies, 181 were done on an outpatient basis and 61 on an inpatient basis, for a 75% outpatient cholecystectomy rate. Presence of acute disease, operating time and sex did not correlate with hospitalization; age and comorbidity did. Twenty-three percent of admitted patients were preselected for admission, usually because of advanced age or presence of comorbidity, but patients of similar age and similar comorbidity were successfully processed as outpatients.
There was a strong correlation between the surgeon and the need for admission (Fig. 1). The outpatient rate seemed to vary directly with volume, the busier surgeons having higher outpatient rates. Each surgeon's practice was similar with respect to acute disease, the incidence of male patients, older patients and patients with greater comorbidity.
Of the 61 patients admitted, 14 (23%) were preselected for admission at the office (medical reasons were cited 11 times, social reasons once and no reason twice) and 12 (20%) were converted to open surgery. A decision or order to admit a patient after surgery was recorded 19 times (31% of admissions): 6 for anesthetic problems (nausea, vomiting, drowsiness, dizziness, anxiety), 3 for pain control, 3 for continued antibiotics, 3 to monitor complications (subcutaneous emphysema, ileus, hypoxia), 2 for social reasons and 2 without any evident reason. For 16 patients (26% of all admitted patients) no reason for admission was documented; these 16 patients were all handled through a "spillover" unit (Fig. 2).
An unexpectedly strong correlation was found between admission and the ward through which patients were processed. Initially, the demand for outpatient facilities exceeded the resources of the day surgery area. Forty-eight outpatients were handled on a temporary spillover unit created on an inpatient ward. These 48 patients had a 46% admission rate, accounting for 22 of the 61 admissions (36%). Excluding patients admitted through the office or converted, there were 216 patients, 169 of whom were processed through the day surgery area with 14 admissions (8%) and 47 through the spillover ward with 21 admissions (45%). Thus, although only 22% of the 216 patients went through the spillover ward, 60% (21 of 35) of all admissions (excluding preselected or converted patients) came from that group of patients. For 16 of the 35 (46%), processing through the spillover ward seemed to be the only reason for admission; no doctor's order to admit was found.
Follow-up study
Of the 273 primary elective cholecystectomies, 259 were done on an outpatient basis for a 95% outpatient cholecystectomy rate, markedly increased over the 75% of the previous year (p < 0.001). Age and comorbidity continued to be significant predictors of hospital admission. A blunting of individual differences between the 4 surgeons was noted, both in volume and outpatient rate (Fig. 1). Whereas previous outpatient rates ranged from 48% to 85%, differences in these rates were no longer significant, ranging from 93% to 96%. All 4 surgeons booked all patients as outpatients without selection in the office.
For all 14 inpatients, the decision to admit was made during the perioperative period. The reason for admission for the 8 nonconverted patients included hypoxia, vomiting, pulmonary edema, atrial fibrillation, urinary retention, observation of a drain, monitoring a coagulopathy and in 1 patient a combination of hypoxia, uncontrolled pain and vomiting. Compared with the previous year, no outpatients were accommodated in inpatient areas. All 5% of admitted patients came through the day surgery area, which compares with the 8% admission rate from this area the previous year.
Both years
There was no difference in the number of patients who returned to the Emergency Department, the readmission rates or conversion rates for the 2 years. Of the 515 patients, 33 were seen in the Emergency Department 1 to 62 days after surgery: 17 for abdominal pain (of whom 2 underwent endoscopic retrograde cholangiopancreatography), 9 for wound infection, 4 for wound bleeding or hematoma, and 1each for vomiting, leg pain and urinary retention. Ten patients were readmitted 4 to 156 days after surgery: 5 with recurrent abdominal pain, 4 of whom had endoscopic removal of a residual common duct stone; 2 for repair of an incisional hernia at the umbilicus; 1 each for a wound infection, fractured hip and percutaneous drainage of a subphrenic abscess. The conversion rate was 3%, with no significant difference between surgeons. Conversion was done for acute cholecystitis 7 times and to define unclear anatomy 10 times; in 3 of the 10 cases, anomalous duct anatomy was found. One patient was found to have an unsuspected hepatocellular carcinoma and was admitted for hepatectomy.
Fig. 3 plots individual surgeon and institutional outpatient rates over time. The institution has a triple plateaued curve, as opposed to a smooth curve for the individual surgeon.
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Discussion
As expected, the uncorrectable factors of age and comorbidity continue to be predictors of potential hospital admission, but neither seems to be a contraindication for outpatient surgery, either alone or in combination. There is no evidence that any patient came to harm because of outpatient status and none of the higher risk outpatients were jeopardized.
Individual variation should not be entirely unexpected at the outset. The participation of all surgeons was voluntary, without monitoring or persuasion. Once differences were made public, the safety of the approach re-emphasized and personal experience increased, individual variation disappeared.
In the present economic climate, most hospitals in Ontario have "closed" beds, and it is very tempting to respond to an increased demand for outpatient space by "reopening" them. Although this has been successful elsewhere, in our setting an area designed for inpatients was not conducive to maximal outpatient management (Fig. 2). For the best outpatient rates, either the temptation to use closed inpatient beds should be resisted or these beds should be given a definite transitory flavour. Toward the end of the first year under study these findings prompted us to expand the facilities of the day surgery area both in size and time, so that outpatient surgery could be scheduled throughout the day to handle all cases.
The readmission rate was 2% and visits to the Emergency Department 5%. None of the readmissions was due to the outpatient status (4 were in patients who had been admitted). Review suggests that 7 of the emergency visits could have been prevented had the patient been kept overnight. However, none was serious and none required readmission. Economically, it is difficult to defend overnight admission of 515 patients in order to prevent 7 visits to the Emergency Department with relatively innocuous complaints requiring no active intervention.
This review reaffirms that laparoscopy has made cholecystectomy a safe outpatient procedure and therefore a suitable hospital routine, successful for most elective patients. The paper also confirms the value of examining one's own results. The preliminary study identified 3 correctable factors. Abandoning preselection, eliminating variations in individual practice and ensuring appropriate day surgery facilities resulted in a significant increase in outpatient cholecystectomy rate from 75% to 95%.
Elimination of individual variation did not require formal guidelines. Comparison of individual results coupled with demonstration of the safety of the outpatient approach for all patients standardized practices voluntarily. Although this may be slower than the use of edict, voluntary change of practice is probably the best test for the usefulness of new therapy. Prudent surgeons would not adopt a therapy voluntarily unless personal experience convinced them of its superiority. Irreversibility is said to be the measure of a revolution. In this regard, this has been a successful revolution, for none of the participating surgeons is willing to return to overnight admission for cholecystectomy.
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Conclusions
Laparoscopy makes outpatient cholecystectomy a safe hospital routine, successful for most elective cholecystectomies. Both age and comorbidity correlate strongly with the need for admission, but neither, alone or together, is a contraindication to safe outpatient surgery. There seems to be no benefit from preselecting higher risk patients for admission. Variations in individual practice and available day surgery facilities also strongly influence outpatient rate.
Neither the 2% readmission rate nor most of the 7% emergency visits seems avoidable by 1- to 2-day hospitalization. Eschewing preselection, eliminating individual variations and ensuring adequate day surgery facilities maximizes institutional outpatient rates to match individual rates.
I am indebted to Ms. Sumi Ignatius of the Health Records Department and Ms. Debbie Harris of the day surgery area at the Salvation Army Scarborough Grace Hospital for their help, and Dr. Robert Mustard and Ms. Diana Schouten for performance and reperformance of the many statistical analyses, only some of which have been reported here. I acknowledge the contribution of my colleagues, Drs. Carlos Alvarez, Jacobo Joffe and Gary Rosenthal, whose practices are also reviewed here.
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References
- Voitk AJ. Outpatient cholecystectomy: implications for hospital utilization. Leadership in Health Services 1994;3:21-3.
- Voitk AJ. Routine outpatient cholecystectomy. Can J Surg 1995;38:262-5.
- Voitk AJ. Outpatient cholecystectomy. J Laparoendosc Surg 1996;6:79-81.
- Dripps RD, Lamont A, Eckenhoff JE. The role of anesthesia in surgical mortality. JAMA 1961;178:261-6.
