Evaluation of methods for characterizing the fine particulate matter emissions from aircraft and other diffusion flame combustion aerosol sources.

The U. S. Environmental Protection Agency in collaboration with the U. S. Air Force Arnold Engineering Development Complex conducted the VAriable Response In Aircraft nvPM Testing (VARIAnT) 3 and 4 test campaigns to compare nonvolatile particulate matter (nvPM) emissions measurements from a variety of diffusion flame combustion aerosol sources (DFCASs), including a Cummins diesel engine, a diesel powered generator, two gas turbine start carts, a J85-GE-5 turbojet engine burning multiple fuels, and a Mini-CAST soot generator. The VARIAnT research program was devised to understand reported variability in the ARP6320A sampling system nvPM measurements. The VARIAnT research program has conducted four test campaigns to date with the VARIAnT 3 and 4 campaigns devoted to: (1) assessing the response of three different black carbon mass analyzers to particles of different size, morphology, and chemical composition; (2) characterizing the particles generated by 6 different combustion sources according to morphology, effective density, and chemical composition; and (3) assessing any significant difference between black carbon as determined by the 3 mass analyzers and the total PM determined via other techniques. Results from VARIAnT 3 and 4 campaigns revealed agreement of about 20% between the Micro-Soot Sensor, the Cavity Attenuated Phase Shift (CAPS PMSSA) monitor and the thermal-optical reference method for elemental carbon (EC) mass, independent of the calibration source used. For the LII-300, the measured mass concentrations in VARIAnT 3 fall within 18% and in VARIAnT 4 fall within 27% of the reference EC mass concentration when calibrated on a combustor rig in VARIAnT 3 and on an LGT-60 start cart in VARIAnT 4, respectively. It was also found that the three mass instrument types (MSS, CAPS PMSSA, and LII-300) can exhibit different BC to reference EC ratios depending on the emission source that appear to correlate to particle geometric mean mobility diameter, morphology, or some other parameter associated with particle geometric mean diameter (GMD) with the LII-300 showing a slightly stronger apparent trend with GMD. Systematic differences in LII-300 measured mass concentrations have been reduced by calibrating with a turbine combustion as a particle source (combustor or turbine engine). With respect to the particle size measurements, the sizing instruments (TSI SMPS, TSI EEPS, and Cambustion DMS 500) were found to be in general agreement in terms of size distributions and concentrations with some exceptions. Gravimetric measurements of the total aerosol mass produced by the various DFCAs differed from the reference EC, BC and integrated particle size distribution measured aerosol masses. The measurements of particle size distributions and single particle analysis performed using the miniSPLAT indicated the presence of larger particles (≳150 nm) having more compact morphologies, higher effective density, and a composition dominated by OC and containing ash. This increased large particle fraction is also associated with higher values of single scattering albedo measured by the CAPS PMSSA instrument and higher OC measurements. These measurements indicate gas turbine engine emissions can be a more heterogeneous mix of particle types beyond the original E-31 assumption that engine exit exhaust particles are mainly composed of black carbon.

Empiric antifungals do not decrease the risk for organ space infection in patients with perforated peptic ulcer.

INTRODUCTION: Infection control in patients with perforated peptic ulcers (PPU) commonly includes empiric antifungals (AF). We investigated the variation in the use of empiric AF and explored the association between their use and the subsequent development of organ space infection (OSI). METHODS: This was a secondary analysis of a multicenter, case-control study of patients treated for PPU at nine institutions between 2011 and 2018. Microbiology and utilization of empiric AF, defined as AF administered within 24 hours from the index surgery, were recorded. Patients who received empiric AF were compared with those who did not. The primary outcome was OSI and secondary outcome was OSI with growth of Candida spp. A logistic regression was used to adjust for differences between the two cohorts. RESULTS: A total of 554 patients underwent a surgical procedure for PPU and had available timing of AF administration. The median age was 57 years and 61% were male. Laparoscopy was used in 24% and omental patch was the most common procedure performed (78%). Overall, 239 (43%) received empiric AF. There was a large variation in the use of empiric AF among participating centers, ranging from 25% to 68%. The overall incidence of OSI was 14% (77/554) and was similar for patients who did or did not receive empiric AF. The adjusted OR for development of OSI for patients who received empiric AF was 1.04 (95% CI 0.64 to 1.70), adjusted p=0.86. The overall incidence of OSI with growth of Candida spp was 5% and was similar for both groups (adjusted OR 1.29, 95% CI 0.59 to 2.84, adjusted p=0.53). CONCLUSION: For patients undergoing surgery for PPU, the use of empiric AF did not yield any significant clinical advantage in preventing OSI, even those due to Candida spp. Use of empiric AF in this setting is unnecessary. STUDY TYPE: Original article, case series. LEVEL OF EVIDENCE: III.

Assessment of a regulatory measurement system for the determination of the non-volatile particulate matter emissions from commercial aircraft engines.

The SAE International has published Aerospace Information Report (AIR) 6241 which outlined the design and operation of a standardized measurement system for measuring non-volatile particulate matter (nvPM) mass and number emissions from commercial aircraft engines. Prior to this research, evaluation of this system by various investigators revealed differences in nvPM mass emissions measurement on the order of 15-30% both within a single sampling system and between two systems operating in parallel and measuring nvPM mass emissions from the same source. To investigate this issue, the U. S. Environmental Protection Agency in collaboration with the U. S. Air Force's Arnold Engineering Development Complex initiated the VAriable Response In Aircraft nvPM Testing (VARIAnT) research program to compare nvPM measurements within and between AIR-compliant sampling systems used for measuring combustion aerosols generated both by a 5201 Mini-CAST soot generator and a J85-GE-5 turbojet engine burning multiple fuels. The VARIAnT research program has conducted four test campaigns to date. The first campaign (VARIAnT 1) compared two essentially identical commercial versions of the sampling system while the second campaign (VARIAnT 2) compared a commercial system to the custom-designed Missouri University of Science and Technology's North American Reference System (NARS) built to the same specifications. Comparisons of nvPM particle mass (i.e., black carbon), number, and size were conducted in both campaigns. Additionally, the sensitivity to variation in system operational parameters was evaluated in VARIAnT 1. Results from both campaigns revealed agreement of about 12% between the two sampling systems, irrespective of manufacturer, in all aspects except for black carbon determination. The major source of measurement differences (20-70%) was due to low BC mass measurements made by the Artium Technologies LII-300 as compared to the AVL 483 Micro-Soot Sensor, the Aerodyne Cavity Attenuated Phase Shift (CAPS PMSSA) monitor, and the thermal-optical reference method for elemental carbon (EC) determination, which was used as the BC reference.

Impact of Biofuel Blends on Black Carbon Emissions from a Gas Turbine Engine.

Presented here is an overview of non-volatile particulate matter (nvPM) emissions, i.e. "soot" as assessed by TEM analyses of samples collected after the exhaust of a J-85 turbojet fueled with Jet-A as well as with blends of Jet-A and Camelina biofuel. A unifying explanation is provided to illustrate the combustion dynamics of biofuel and Jet-A fuel. The variation of primary particle size, aggregate size and nanostructure are analyzed as a function of biofuel blend across a range of engine thrust levels. The postulate is based on where fuels start along the soot formation pathway. Increasing biofuel content lowers aromatic concentration while placing increasing dependence upon fuel pyrolysis reactions to form the requisite concentration of aromatics for particle inception and growth. The required "kinetic" time for pyrolysis reactions to produce benzene and multi-ring PAHs allows increased fuel-air mixing by turbulence, diluting the fuel-rich soot-forming regions, effectively lowering their equivalence ratio. With a lower precursor concentration, particle inception is slowed, the resulting concentration of primary particles is lowered and smaller aggregates were measured. The lower equivalence ratio also results in smaller primary particles because of the lower concentration of growth species.

Postoperative Opioid Prescription Reduction Strategy in a Regional Healthcare System.

BACKGROUND: The CDC reported in 2017 that the largest increments in probability of continued use were observed after days 5 and 31 on opioid therapy. This study demonstrates the correlation between a system-wide pain management and opioid stewardship effort with reductions in discharge prescriptions for elective surgical patients. STUDY DESIGN: Discharge prescriptions were monitored through the electronic health record. Baseline prescribing patterns were established for the first quarter of 2018, preceding the first intervention in the multipronged opioid reduction initiative. Beginning in the second quarter of 2018, a series of pain management and opioid stewardship educational conferences were provided. Enhanced Recovery after Surgery protocols were simultaneously implemented system-wide. In the third quarter of 2018, a quality metric linked to compensation rewarded surgeons for limiting postoperative discharge prescriptions to 5 or fewer days. Opioid prescriptions were compared by quarter from January 2018 to March 2019 using chi-square and Kruskal-Wallis test with significance of p < 0.05. RESULTS: There were 31,814 patients who underwent elective surgical procedures during the study period. At baseline, the rate of postoperative opioid prescriptions of 5 or fewer days was 81%. This rate increased to 82%, 86%, 89%, and 92% in each successive quarter (p < 0.0001 for quarters 3 to 5). CONCLUSIONS: A system-wide, multipronged pain management and opioid reduction program significantly reduced opioid discharge prescriptions written for more than 5 days. This approach can serve as a model for other healthcare systems attempting to reduce opioid prescribing and combat the opioid crisis in the US.

Protocol driven management of suspected common duct stones: A Southwestern Surgical Congress multi-centered trial.

BACKGROUND: Several options exist for the diagnosis and management of suspected common duct stones. We hypothesized that a protocol-directed approach would shorten length of stay in this patient population. METHODS: Patients from four participating institutions with a peak bilirubin <4 mg/dL underwent surgery as the initial procedure, whereas patients with a bilirubin ≥4 mg/dL underwent endoscopy. The primary endpoint was length of stay. Analysis involved chi square and Wilcoxon-Mann-Whitney test with significance at p < 0.05. RESULTS: 214 patients were managed under the protocol during six-month study period. 111 patients (52%) required endoscopy and surgery. Length of stay and the number of MRCPs performed pre-operatively significantly decreased following protocol implementation (p < 0.05). CONCLUSIONS: "Surgery first" approach in patients with bilirubin <4 ml/dL resulted in low morbidity and mortality, reduced MRCP, and length of stay.

Laparoscopic omental patch for perforated peptic ulcer disease reduces length of stay and complications, compared to open surgery: A SWSC multicenter study.

RCTs showed benefits in Lap repair of perforated peptic ulcer (PPU). The SWSC Multi-Center Trials Group sought to evaluate whether Lap omental patch repairs compared to Open improved outcomes in PPU in general practice. Data was collected from 9 SWSC Trial Group centers. Demographics, operative time, 30-day complications, length of stay and mortality were included. 461 PATIENTS: Open in 311(67%) patients, Lap in 132(28%) with 20(5%) patients converted from Lap to Open. Groups were similar at baseline. Significant variability was found between centers in their utilization of Lap (0-67%). Complications at 30 days were lower in Lap (18.5% vs. 27.5%, p < 0.05) as was unplanned re-operation (4.7% vs 14%, p < 0.05). Lap reduced LOS (6 vs 8 days, p < 0.001). Ileus was more in Lap (42% vs 18 p < 0.001) operative time was 14 min higher in Lap(p < 0.01) and admission to OR time was 4 h higher in Lap(<0.05). No significant difference readmission or mortality. Our results suggest Lap should be considered a first-line option in suitable PPU patients requiring omental patch repair in centers that have the capacity and resources 24/7.

The southwestern surgical congress multi-center trial on suspected common duct stones.

BACKGROUND: Choledocholithiasis is present in up to 15% of cholecystectomy patients. Treatment can be surgical, endoscopic, or via interventional radiology. We hypothesized significant heterogeneity between hospitals exists in the approach to suspected common duct stones. METHODS: A retrospective review of patients that had a preoperative MRCP, endoscopic ultrasound, endoscopic retrograde cholangiopancreatogram (ERCP), or intra-operative cholangiogram was performed. Comparisons were by Wilcoxon-Mann-Whitney tests with significance of p < 0.05 for paired variables and p < 0.017 for multiple comparisons. RESULTS: Twelve participating institutions identified 1263 patients (409 men and 854 women) with a median age of 49 years (IQR: 31-94). Liver function tests (LFT's) were elevated in 939 patients (75%), median bilirubin level 1.75 mg/dl (IQ: 0.8-3.7 mg/dl) and median common duct size 7 mm (IQR 5-10 mm). The most common initial procedure was cholecystectomy with IOC at seven institutions, endoscopy at four and MRCP at one. CONCLUSION: Significant variation exists within the surgical community regarding suspected common duct stones. These results underscore the need for a protocol for common duct stones to minimize multiple, redundant interventions.

Surgical Site Infection after Primary Closure of High-Risk Surgical Wounds in Emergency General Surgery Laparotomy and Closed Negative-Pressure Wound Therapy.

BACKGROUND: We hypothesized that the universal adoption of closed wounds with negative pressure wound therapy (NPWT) in emergency general surgery patients would result in low superficial surgical infection (SSI) rates. STUDY DESIGN: We performed a retrospective observational study using primary wound closure with external NPWT, from May 2017 to May 2018. Patients with active soft tissue infection of the abdominal wall were excluded. Data were analyzed by Fisher's exact tests and Wilcoxon-Mann-Whitney tests, with significance is set at a value of p < 0.05. RESULTS: Eighty-five patients (53% female) with a median age of 65 years (range 19 to 98 years) underwent laparotomies. Four patients were excluded for active soft tissue infection. Wounds were classified as dirty (n = 18), contaminated (n = 52), and clean contaminated (n = 11). Median BMI was 27 kg/m2 (interquartile range [IQR] 23.4 to 33.0 kg/m2). Median antibiotic therapy was 4 days (IQR 1 to 7 days). Twenty-six patients had open abdomen management. Patient follow-up was a median of 20 days (range 14 to 120 days). Six patients (7%) developed superficial SSI requiring conversion to open wound management. No patients developed fascial dehiscence. There were no statistically significant associations between SSI and wound class (p = 0.072), antibiotic duration (p = 0.702), open abdomen management, or preoperative risk factors (p < 0.1). Overall morbidity was 38% and mortality was 6%. CONCLUSIONS: Primary closure of high risk incisions combined with NPWT is associated with acceptably low SSI rates. Due to the low morbidity and decreased cost associated with this technique, primary closure with NPWT should replace open wound management in the emergency general surgery population.

Comparison of a standardized negative pressure wound therapy protocol after midline celiotomy to primary skin closure and traditional open wound vacuum-assisted closure management.

A negative pressure wound therapy (NPWT) protocol using Hydrofera Blue® bacteriostatic foam wicks and silver-impregnated foam overlay to close midline skin incisions after emergency celiotomy was compared to primary skin closure only and traditional open wound vacuum-assisted closure management as part of a quality improvement initiative. This single-institution retrospective cohort study assessed all consecutive emergency celiotomies from July 2013 to June 2014 excluding clean wounds. Included variables were demographics, wound classification, NPWT days, and surgical site occurrences (SSOs). Primary outcome was days of NPWT. Secondary outcomes included SSOs (surgical site infections, fascial dehiscence, return to operating room). Analysis used exact chi-square between categorical variables, Kruskal-Wallis for analysis of variance for ordinal and categorical variables, and Wilcoxon rank sum for total days of NPWT. One hundred fifty-eight patients underwent emergency celiotomy with primary skin closure (n = 51), open NPWT (n = 63), or the NPWT protocol (n = 44). There was no difference in American Society of Anesthesiologists Physical Status score, body mass index, wound classification, or SSO between the three groups. Total NPWT days were reduced in protocol versus open NPWT (median 3 vs 20.5 days, range 3-51 vs 3-405 days, P = 0.001). Primary skin closure and NPWT protocol had fewer patients discharged with NPWT than open NWPT (0% and 14% vs 63.5%, P < 0.0001, odds ratio = 10.7, 95% confidence interval 3.7-35.1). Primary skin closure and NPWT protocol decrease NPWT usage days and maintain low SSOs in emergency midline celiotomy incisions.

Open vs Closed Negative Pressure Wound Therapy for Contaminated and Dirty Surgical Wounds: A Prospective Randomized Comparison.

BACKGROUND: A new proprietary negative pressure wound device has been developed to apply negative pressure therapy to closed wounds (closed-NPWT). We postulated that closed-NPWT management of contaminated and dirty wounds would lead to faster wound healing and no significant difference in wound complications. STUDY DESIGN: An IRB approved, prospective randomized trial was performed. Patients were consented preoperatively, but not entered nor assigned treatment until intraoperative findings were known. Patients were randomly assigned to either open-NPWT or a wound closed with skin staples and external closed-NPWT. Primary outcome was time to complete wound healing, defined as complete epithelization of the wound. Secondary outcomes were wound complications including wound infection, seroma, and dehiscence. Statistical analysis was performed using chi-square test, Fisher exact test, t-test, and Wilcoxon Rank-Sum test with significance of p < 0.05. RESULTS: Twenty-five closed-NPWT and 24 open-NPWT patients were analyzed. There were no significant differences in sex, mean age, BMI, smoking history, steroid use, comorbidities, or indication for surgery in the 2 groups. One patient in the open-NPWT group and 2 patients in the closed-NPWT group developed a wound infection (p = 1.0). Four open-NPWT and 3 closed-NPWT patients died from complications unrelated to the wound. Wound healing occurred at a median of 48 days (range 6 to 126 days) for the open-NPWT group vs a median of 7 days (range 6 to 12 days) for the closed-NPWT group (p < 0.0001). CONCLUSIONS: Wound healing was significantly faster in contaminated and dirty wounds when managed with closed-NPWT. There was no difference in wound complications between the 2 treatment groups. This approach shows promise for closed management of contaminated and dirty wounds and warrants additional prospective studies with larger patient groups.

Risky business? Investigating outcomes of patients undergoing urgent laparoscopic appendectomy on antithrombotic therapy.

INTRODUCTION: The literature regarding outcomes in patients on irreversible antithrombotic therapy (IAT) undergoing urgent laparoscopic appendectomy is limited. The aim of this multicenter retrospective study was to examine the impact of prehospital IAT on outcomes in this population. METHODS: From 2010 to 2014, seven institutions from the Southwest Surgical Multicenter Trials (SWSC MCT) group conducted a retrospective study to evaluate the clinical course of all patients on IAT who underwent urgent/emergent laparoscopic appendectomy. The IAT+ group was subdivided into IAT+ (Aspirin only) and IAT+ (Aspirin-Plavix). These groups were matched 1:1 to controls. The primary outcomes were estimated blood loss (EBL) and transfusion requirement. Secondary outcomes included infections (SSI - Surgical Site Infection, DSI - Deep Space Infection, and OSI - Organ Space Infection), hospital length of stay (HLOS), complications, 30-day readmissions, and mortality. RESULTS: Out of the 2903 patients included in the study, 287 IAT+ patients were identified and matched in a 1:1 ratio to 287 IAT-patients. In the IAT+ vs IAT-analysis, no significant differences in EBL (p = 1.0), transfusion requirement during the preoperative (p = 0.5), intraoperative (p = 0.3) or postoperative periods (p = 0.5), infectious complications (SSI; p = 1.0, DSI; p = 1.0, and OSI; p = 0.1), overall complications (p = 0.3), HLOS (p = 0.7), 30-day readmission (p = 0.3), or mortality (p = 0.1) were noted. Similarly, outcomes in the IAT+ (Aspirin only) and IAT+ (Aspirin-Plavix) subgroups failed to demonstrate any significant differences when compared to controls. CONCLUSIONS: Our analysis suggests that IAT is not associated with worse outcomes in urgent/emergent laparoscopic appendectomy. Prehospital use of IAT should not be used to delay laparoscopic appendectomy.

Outpatient laparoscopic appendectomy can be successfully performed for uncomplicated appendicitis: A Southwestern Surgical Congress multicenter trial.

BACKGROUND: Many laparoscopic procedures are now performed on an outpatient basis. We hypothesize laparoscopic appendectomy can be safely performed as an outpatient procedure. METHODS: Seven institutions adopted a previously described outpatient laparoscopic appendectomy protocol for uncomplicated appendicitis. Patients were dismissed unless there was a clinical indication for admission. Patient demographics, success with outpatient management, time of dismissal, morbidity, and readmissions were analyzed. RESULTS: Two hundred six men and one hundred seventy women with a mean age of 35.4 years were included in the protocol. Seventy-eight patients (21%) had pre-existing comorbidities. 299 patients (80%) were managed as outpatients. There were no conversions to open appendectomy. Postoperative morbidity was 5%. The time of patient dismissals was evenly distributed throughout the day and night. Twelve patients (3%) required readmission. Outpatient follow-up occurred in 63% of patients. CONCLUSIONS: An outpatient laparoscopic appendectomy protocol was successfully applied at multiple institutions with low morbidity and low readmission rates. Application of this practice nationally could reduce length of stay and decrease overall health care costs for acute appendicitis.

Protocol-Driven Management of Suspected Common Duct Stones.

BACKGROUND: Common duct stones can be diagnosed by magnetic resonance cholangiopancreatography (MRCP), endoscopic ultrasound (EUS)/ERCP, and intraoperative cholangiogram (IOC). In 2015, our group adopted a standard approach of preoperative EUS/ERCP followed by laparoscopic cholecystectomy for patients with an admission bilirubin >4.0 mg/dL. For bilirubin <4.0 mg/dL, laparoscopic cholecystectomy with IOC was the initial procedure. Postoperative EUS/ERCP with endoscopic sphincterotomy was pursued for positive IOC. Exclusions included clinical suspicion of malignancy and surgically altered anatomy making endoscopic management impractical. STUDY DESIGN: A retrospective comparison of protocol and pre-protocol (baseline) patients was performed, looking at patient demographics, presence of pancreatitis, common duct stone risk factors, comorbidities, length of hospitalization, and postoperative morbidity. Statistical analysis was performed with t-test, chi-square, and Wilcoxon rank-sum test with significance at p < 0.05. RESULTS: There were 56 patients in each group, with a mean ± SD age of 50.5 ± 20.88 years and 49.3 ± 20.92 years, respectively (p = NS). There were no significant differences between baseline and protocol patients with respect to individual and cumulative preoperative comorbidities, pancreatitis, elevation of liver function tests, bilirubin, common duct size, and postoperative morbidity. There were fewer endoscopies (22 vs 35; p = 0.014), and shorter length of stay in protocol patients (2.8 days vs 3.8 days; p = 0.025). CONCLUSIONS: Protocol-driven management of patients with suspected common duct stones reduced the number of endoscopies and length of hospitalization, with no change in postoperative morbidity. This approach has the potential to decrease endoscopy-related morbidity and overall cost without affecting quality of care.

Fast track pathway for perforated appendicitis.

BACKGROUND: Perforated appendicitis is associated with an increased morbidity and length of stay. "Fast track" protocols have demonstrated success in shortening hospitalization without increasing morbidity for a variety of surgical processes. This study evaluates a fast track pathway for perforated appendicitis. METHODS: In 2013, a treatment pathway for perforated appendicitis was adopted by the Acute Care Surgery Service for patients having surgical management of perforated appendicitis. Interval appendectomy was excluded. Patients were treated initially with intravenous antibiotics and transitioned to oral antibiotics and dismissed when medically stable and tolerating oral intake. A retrospective review of patients managed on the fast track pathway was undertaken to analyze length of stay, morbidity, and readmissions. RESULTS: Thirty-four males and twenty-one females with an average age of 46.8 years underwent laparoscopic appendectomy for perforated appendicitis between January 2013 and December 2014. Pre-existing comorbidities included hypertension 42%, diabetes mellitus 11%, COPD 5% and heart disease 2%. No patient had conversion to open appendectomy. Average length of stay was 2.67 days and ranged from 1 to 12 days (median 2 days). Postoperative morbidity was 20% and included abscess (6 patients), prolonged ileus (3 patients), pneumonia (1 patient), and congestive heart failure (1 patient). Five patients were readmitted for abscess (3 patients), congestive heart failure (1 patient), and pneumonia (1 patient). CONCLUSION: A fast track pathway for perforated appendicitis produced shorter length of stay and acceptable postoperative morbidity and readmission. This offers the potential for significant cost savings over current national practice patterns.

Patient Satisfaction After Outpatient Appendectomy.

BACKGROUND: Outpatient laparoscopic appendectomy has been shown to be safe, with low morbidity and readmission rates, but whether outpatient appendectomy produces poorer patient satisfaction has been questioned. MATERIALS AND METHODS: Preoperatively, patients with uncomplicated appendicitis were counselled regarding outpatient management and instructed on postoperative care, follow-up appointments, and contact information. Telephone surveys of patients who underwent an outpatient laparoscopic appendectomy for uncomplicated appendicitis from January through October 2013 were performed. A Likert scale from very dissatisfied (1) to very satisfied (5) was employed. Patients were also queried that if, given the opportunity, they would have chosen to stay in the hospital. RESULTS: Qualified patients included 41 men and 31 women with an average age of 36 years (range 19-79 years). Fifty-four (75%) were reached for satisfaction surveys. Patients were dismissed from the recovery room following a previously published protocol for outpatient management from 6 a.m. to noon (24%), noon to 6 p.m. (17%), 6 p.m. to midnight (22%), and midnight to 6 a.m. (37%). The average satisfaction score for outpatient management was 4.6 (range 2-5). Six patients (11%) stated that they would have preferred hospitalization, if given the opportunity. The reasons included inadequate pain control (2 patients); lack of home assistance (2 patients); nausea and vomiting (1 patient); and prolonged drowsiness (1 patient). Four of these patients violated the outpatient management guidelines (pain controlled on oral analgesics and adequate home assistance). CONCLUSION: Outpatient laparoscopic appendectomy can be performed with high patient satisfaction, but adherence to protocol guidelines for outpatient management is important to properly select patients for outpatient management and to maximize patient satisfaction.