ABSTRACT
BACKGROUND: Enhanced recovery after surgery (ERAS) protocols are widely employed in colorectal surgery, successful in reducing postoperative morbidities and hospital length of stay (LOS). However, ERAS effects on the inflammatory bowel disease population remain unclear. This study examines the postoperative course of both Crohn's disease (CD) and colon cancer (CC) patients after elective right hemicolectomies and compares the effectiveness of ERAS protocol. METHODS: A retrospective analysis was performed on patients with CD and CC undergoing elective right hemicolectomies and ileocecectomies from January 2014 through June 2016 (pre-ERAS) and January 2017 through April 2019 (post-ERAS) from a single tertiary care center. Patient demographics and perioperative variables were examined, including prolonged postoperative ileus (PPOI), hospital LOS, and 30-day readmission. RESULTS: 98 CC patients and 91 CD patients met the inclusion criteria. The pre-ERAS CC and post-ERAS CC cohorts were significantly different: post-ERAS had fewer patients with congestive heart failure and chronic obstructive pulmonary disease and had higher albumin levels. The pre-ERAS CC cohort had significantly longer operative durations and higher rates of concomitant procedures than the post-ERAS CC cohort. Both patients with CC and CD had a reduction in LOS with implementation of ERAS, decreasing by 2.24 days (P = .002) and 1.21 days (P = .038), respectively. There was a reduction in rates of organ space infections with CD (pre .132, post .00, P = .007). There was a trend towards an increased rate of PPOI with CD (Pre .079, Post .226, P = .062). DISCUSSION: The ERAS protocol significantly reduced LOS for both groups, without increasing 30-day readmission rates or other morbidities.
Subject(s)
Colonic Neoplasms/surgery , Crohn Disease/surgery , Elective Surgical Procedures , Enhanced Recovery After Surgery , Length of Stay , Aged , Elective Surgical Procedures/adverse effects , Female , Heart Failure/epidemiology , Humans , Ileum/surgery , Ileus/epidemiology , Ileus/prevention & control , Male , Operative Time , Patient Readmission , Postoperative Complications/epidemiology , Postoperative Complications/prevention & control , Pulmonary Disease, Chronic Obstructive/epidemiology , Retrospective Studies , Treatment OutcomeABSTRACT
Brown carbon (BrC), which may include secondary organic aerosol (SOA), can be a significant climate-forcing agent via its optical absorption properties. However, the overall contribution of SOA to BrC remains poorly understood. Here, correlations between oxidation level and optical properties of SOA are examined. SOA was generated in a flow reactor in the absence of NOx by OH oxidation of gas-phase precursors used as surrogates for anthropogenic (naphthalene, tricyclo[5.2.1.0(2,6)]decane), biomass burning (guaiacol), and biogenic (α-pinene) emissions. SOA chemical composition was characterized with a time-of-flight aerosol mass spectrometer. SOA mass-specific absorption cross sections (MAC) and refractive indices were calculated from real-time cavity ring-down photoacoustic spectrometry measurements at 405 and 532 nm and from UV-vis spectrometry measurements of methanol extracts of filter-collected particles (300 to 600 nm). At 405 nm, SOA MAC values and imaginary refractive indices increased with increasing oxidation level and decreased with increasing wavelength, leading to negligible absorption at 532 nm. Real refractive indices of SOA decreased with increasing oxidation level. Comparison with literature studies suggests that under typical polluted conditions the effect of NOx on SOA absorption is small. SOA may contribute significantly to atmospheric BrC, with the magnitude dependent on both precursor type and oxidation level.
Subject(s)
Aerosols/chemistry , Organic Chemicals/chemistry , Bicyclic Monoterpenes , Carbon/chemistry , Monoterpenes/chemistry , Naphthalenes/chemistry , Oxidation-ReductionABSTRACT
Functionalization (oxygen addition) and fragmentation (carbon loss) reactions governing secondary organic aerosol (SOA) formation from the OH oxidation of alkane precursors were studied in a flow reactor in the absence of NO(x). SOA precursors were n-decane (n-C10), n-pentadecane (n-C15), n-heptadecane (n-C17), tricyclo[5.2.1.0(2,6)]decane (JP-10), and vapors of diesel fuel and Southern Louisiana crude oil. Aerosol mass spectra were measured with a high-resolution time-of-flight aerosol mass spectrometer, from which normalized SOA yields, hydrogen-to-carbon (H/C) and oxygen-to-carbon (O/C) ratios, and C(x)H(y)+, C(x)H(y)O+, and C(x)H(y)O(2)+ ion abundances were extracted as a function of OH exposure. Normalized SOA yield curves exhibited an increase followed by a decrease as a function of OH exposure, with maximum yields at O/C ratios ranging from 0.29 to 0.74. The decrease in SOA yield correlates with an increase in oxygen content and decrease in carbon content, consistent with transitions from functionalization to fragmentation. For a subset of alkane precursors (n-C10, n-C15, and JP-10), maximum SOA yields were estimated to be 0.39, 0.69, and 1.1. In addition, maximum SOA yields correspond with a maximum in the C(x)H(y)O+ relative abundance. Measured correlations between OH exposure, O/C ratio, and H/C ratio may enable identification of alkane precursor contributions to ambient SOA.
