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Abstract
BACKGROUND Geriatric patients requiring emergency general surgery (EGS) have significant risk of morbidity and mortality. Rural patients face decreased access to care. We sought to characterize the EGS needs and impact of rurality for geriatric residents of New Hampshire. STUDY DESIGN A retrospective cohort study of the New Hampshire Uniform Healthcare Facility Discharge Dataset, including patients 65 years and older with urgent/emergent admission who underwent 1 of 7 EGS procedures, grouped by urban or rural county of residence, discharged between 2012-2015. RESULTS New Hampshire has 26 acute care hospitals: 10 (38.5%) are in urban counties and 16 (61.5%) are in rural counties. Thirteen (50.0%) are critical access hospitals (1 urban and 12 rural). Of 2,445 geriatric patient discharges, 40% of patients were from rural counties and were demographically similar to urban patients. Rural patients were more likely to present as a hospital transfer (15.4% vs 2.5%, p < 0.01), receive care at a critical access hospital (24.1% vs 1.0%, p < 0.01), receive care outside their home county (32.5% vs 12.8%, p < 0.01), and be transferred to another hospital after surgery. Rural and urban patients underwent similar procedures, with similar lengths of stay, cost of index hospitalization, and mortality. CONCLUSIONS Rural geriatric patients in New Hampshire are more likely to receive care outside of their home county or be transferred to another hospital. Costs of care were similar but are likely underestimated for rural patients. There was no difference in unadjusted mortality. Further investigation is merited to determine the reasons for hospital transfer in the geriatric EGS population to evaluate which patients may benefit most from remaining close to home vs transferring to other facilities.
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Affiliation(s)
- Charles P Burney
- From the Department of Surgery, Dartmouth-Hitchcock Medical Center, Lebanon, NH (Burney, Baumann, Briggs)
- Geisel School of Medicine at Dartmouth, Hanover, NH (Burney, Baumann, Carlos, Briggs)
| | - Laura Baumann
- From the Department of Surgery, Dartmouth-Hitchcock Medical Center, Lebanon, NH (Burney, Baumann, Briggs)
- Geisel School of Medicine at Dartmouth, Hanover, NH (Burney, Baumann, Carlos, Briggs)
| | - Heather A Carlos
- Geisel School of Medicine at Dartmouth, Hanover, NH (Burney, Baumann, Carlos, Briggs)
| | - Alexandra Briggs
- From the Department of Surgery, Dartmouth-Hitchcock Medical Center, Lebanon, NH (Burney, Baumann, Briggs)
- Geisel School of Medicine at Dartmouth, Hanover, NH (Burney, Baumann, Carlos, Briggs)
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Brown DR, Burney CP, Nevil GK, Gray PJ, Eid MA, Sorensen MJ. Extreme Elevation of Baseline Intraoperative Parathyroid Hormone Measurements: Should Usual Protocols Apply? J Surg Res 2023; 283:1073-1077. [PMID: 36914998 DOI: 10.1016/j.jss.2022.11.040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 11/08/2022] [Accepted: 11/11/2022] [Indexed: 12/15/2022]
Abstract
INTRODUCTION Intraoperative parathyroid hormone (IOPTH) monitoring is routinely used to facilitate minimally invasive parathyroidectomy. Many IOPTH protocols exist for predicting biochemical cure. Some patients are found to have extremely high baseline IOPTH levels (defined in this study as >500 pg/mL), which may affect the likelihood of satisfying certain final IOPTH criteria. We aimed to discover whether clinically significant differences exist in patients with extremely high baseline IOPTH and which IOPTH protocols are most appropriately applied to these patients. MATERIALS AND METHODS This is a retrospective review of 237 patients who underwent parathyroidectomy with IOPTH monitoring for primary hyperparathyroidism (pHPT) from 2016 to 2020. Baseline IOPTH levels, drawn prior to manipulation of parathyroid glands, were grouped into categories labeled "elevated" (>65-500 pg/mL) and "extremely elevated" (>500 pg/mL). Final IOPTH levels were analyzed to determine whether there was a >50% decrease from baseline and whether a normal IOPTH value was achieved. 6-wk postoperative calcium levels were also examined. RESULTS Of the patients in this cohort, 76% were in the elevated group and 24% in the extremely elevated group. Male sex and higher preoperative PTH levels were correlated with higher baseline IOPTH levels. Patients with extremely elevated baseline IOPTH were less likely to have IOPTH fall into normal range at the conclusion of the case (P = 0.019), and final IOPTH levels were higher (P < 0.001), but the IOPTH was equally likely to decrease >50% from baseline. There was no difference in the mean postoperative calcium levels between the two groups at 6-wk or at longer term follow-up (mean 525 d). CONCLUSIONS Detection of baseline IOPTH levels >500 pg/mL during parathyroidectomy performed for pHPT is not uncommon. IOPTH in patients with extremely elevated baseline levels were less likely to fall into normal range, but follow-up calcium levels were equal, suggesting that applying more stringent IOPTH criteria for predicting biochemical cure may not be appropriate for this population.
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Affiliation(s)
- David R Brown
- Geisel School of Medicine at Dartmouth College, Hanover, New Hampshire
| | | | - Grace K Nevil
- Geisel School of Medicine at Dartmouth College, Hanover, New Hampshire
| | - Phillip J Gray
- Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire
| | - Mark A Eid
- Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire
| | - Meredith J Sorensen
- Geisel School of Medicine at Dartmouth College, Hanover, New Hampshire; Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire.
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Barthold LK, Burney CP, Baumann LE, Briggs A. Complexity of Transferred Geriatric Adults Requiring Emergency General Surgery: A Rural Tertiary Center Experience. J Surg Res 2023; 283:640-647. [PMID: 36455417 DOI: 10.1016/j.jss.2022.10.088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 08/22/2022] [Accepted: 10/16/2022] [Indexed: 11/29/2022]
Abstract
INTRODUCTION As the American population ages, the number of geriatric adults requiring emergency general surgery (EGS) care is increasing. EGS regionalization could significantly affect the pattern of care for rural older adults. The aim of this study was to determine the current pattern of care for geriatric EGS patients at our rural academic center, with a focus on transfer status. MATERIALS AND METHODS We performed a retrospective chart review of patients aged ≥65 undergoing EGS procedures within 48 h of admission from 2014 to 2019 at our rural academic medical center. We collected demographic, admission, operative, and outcomes data. The primary outcomes of interest were mortality and nonhome discharge. Univariate and multivariate analyses were performed. RESULTS Over the 5-y study period, 674 patients underwent EGS procedures, with 407 (60%) transferred to our facility. Transfer patients (TPs) had higher American Society of Anesthesiology (ASA) scores (P < 0.001), higher rates of open abdomen (13% versus 5.6%, P = 0.001), and multiple operations (24 versus 11%, P < 0.001) than direct admit patients. However, after adjustment there was no difference in mortality (OR 1.64; 95% CI, 0.82-3.38) or nonhome discharge (OR 1.49; 95% CI, 0.95-2.36). CONCLUSIONS At our institution, the majority of rural geriatric EGS patients were transferred from another hospital for care. These patients had higher medical and operative complexity than patients presenting directly to our facility for care. After adjustment, transfer status was not independently associated with in-hospital mortality or nonhome discharge. These patients were appropriately transferred given their level of complexity.
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Affiliation(s)
- Laura K Barthold
- Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire
| | - Charles P Burney
- Department of Surgery, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire
| | - Laura E Baumann
- Department of Surgery, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire
| | - Alexandra Briggs
- Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire; Department of Surgery, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire.
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Allen RW, Shaw RD, Burney CP, Newton LE, Lee AY, Judd BG, Ivatury SJ. Deep sleep and beeps II: Sleep quality improvement project in general surgery patients. Surgery 2022; 172:1697-1703. [PMID: 38375787 DOI: 10.1016/j.surg.2022.09.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2022] [Revised: 09/02/2022] [Accepted: 09/10/2022] [Indexed: 11/06/2022]
Abstract
BACKGROUND Poor sleep leads to poor health outcomes. Phase I of our sleep quality improvement project showed severe sleep disturbance in the ward setting. We implemented a novel PostOp Pack to improve sleep quality. METHODS Patients underwent elective, general surgery procedures. Fitbit trackers measured total sleep time. Patients completed the inpatient Richards-Campbell Sleep Questionnaire, which combines 5 domains into a cumulative score (0-100). Patients completed the outpatient Pittsburgh Sleep Quality Index preoperatively and postoperatively. Patients received the PostOp Pack, which included physical items and a sleep-protective order set to reduce nighttime awakenings. Patients from phase I served as the historical control. The primary outcome was the percentage of patients with Richards-Campbell Sleep Questionnaire total sleep score ≥50. The secondary outcomes included the mean Richards-Campbell Sleep Questionnaire domain scores and Fitbit total sleep time. RESULTS A total of 49 patients were compared with 64 historical controls. The percentage of patients with a total sleep score ≥50 was significantly higher in patients receiving a PostOp Pack versus historical control (69% vs. 44%, difference 26%, 95% confidence interval 6.1-45%, P = .01). The mean Richards-Campbell Sleep Questionnaire Total Sleep Score was significantly higher in patients with a PostOp Pack (62 vs 49, mean difference 13, 95% confidence interval 6-21, P ≤ .01). The PostOp Pack Richards-Campbell Sleep Questionnaire domain scores were significantly higher in various areas: Sleep Latency (68 vs 49, P ≤ .01), Awakenings (56 vs 40, P = .01), Sleep Quality (61 vs 49, P = .02), and Noise Disturbance (70 vs 59, P = .04). Of all patients, 92% would use PostOp Pack again in a future hospitalization. No patients had a failure to rescue event with PostOp Pack. The mean total sleep time was significantly improved with PostOp Pack on night 1 (6.4 vs 4.7 hours, P = .03). CONCLUSION The PostOp Pack improves inpatient sleep quality and is safe.
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Affiliation(s)
- Robert W Allen
- Department of Surgery, Dartmouth-Hitchcock Medical Center, Lebanon, NH.
| | - Robert D Shaw
- Department of Surgery, Dartmouth-Hitchcock Medical Center, Lebanon, NH
| | - Charles P Burney
- Department of Surgery, Dartmouth-Hitchcock Medical Center, Lebanon, NH
| | - Laura E Newton
- Geisel School of Medicine, Dartmouth College, Lebanon, NH
| | - Andrew Y Lee
- Geisel School of Medicine, Dartmouth College, Lebanon, NH
| | - Brooke G Judd
- Department of Surgery, Dartmouth-Hitchcock Medical Center, Lebanon, NH; Geisel School of Medicine, Dartmouth College, Lebanon, NH; Sleep Center, Dartmouth-Hitchcock Medical Center, Lebanon, NH
| | - Srinivas Joga Ivatury
- Department of Surgery and Perioperative Care, University of Texas Dell Medical School, Austin TX
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Roginski MA, Burney CP, Husson EG, Harper KR, Atchinson PRA, Munson JC. Influence of Critical Care Transport Ventilator Management on Intensive Care Unit Care. Air Med J 2022; 41:96-102. [PMID: 35248352 DOI: 10.1016/j.amj.2021.10.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Revised: 09/16/2021] [Accepted: 10/13/2021] [Indexed: 11/28/2022]
Abstract
OBJECTIVE High tidal volume ventilation is associated with ventilator-induced lung injury. Early introduction of lung protective ventilation improves patient outcomes. This study describes ventilator management during critical care transport and the association between transport ventilator settings and ventilator settings in the intensive care unit (ICU). METHODS This was a retrospective review of mechanically ventilated adult patients transported to an academic medical center via a critical care transport program between January 2018 and April 2019. Ventilator settings during transport were compared with the initial and 6- and 12-hour postadmission ventilator settings. RESULTS Three hundred eighty patients were identified; 114 (30%) received tidal volumes > 8 mL/kg predicted body weight at the time of transfer. The transport handoff tidal volume strongly correlated with the ICU tidal volume (Pearson r = 0.7). Patients receiving high tidal volumes during transport were more likely to receive high tidal volumes initially upon transfer (relative risk [RR] = 4.6; 95% confidence interval [CI], 3.3-6.5) and at 6 and 12 hours after admission (RR = 2.6; 95% CI, 1.8-3.8 and RR = 2.7; 95% CI, 1.7-4.3, respectively). CONCLUSION Exposure to high tidal volumes during transport is associated with high tidal volume ventilation in the ICU, even up to 12 hours after admission. This study identifies opportunities for improving patient care through the application of lung protective ventilation strategies during transport.
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Affiliation(s)
- Matthew A Roginski
- Department of Emergency Medicine, Dartmouth-Hitchcock Medical Center, Lebanon, NH; Department of Medicine, Section of Pulmonary and Critical Care Medicine, Dartmouth-Hitchcock Medical Center, Lebanon, NH.
| | - Charles P Burney
- Department of Surgery, Dartmouth-Hitchcock Medical Center, Lebanon, NH
| | | | | | - Patricia Ruth A Atchinson
- Department of Emergency Medicine, Dartmouth-Hitchcock Medical Center, Lebanon, NH; Department of Medicine, Section of Pulmonary and Critical Care Medicine, Dartmouth-Hitchcock Medical Center, Lebanon, NH
| | - Jeffrey C Munson
- Department of Medicine, Section of Pulmonary and Critical Care Medicine, Dartmouth-Hitchcock Medical Center, Lebanon, NH; Dartmouth Institute for Health Policy and Clinical Practice, Lebanon, NH
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Burney CP, Goldwag JL, Sorensen MJ, Crockett AO. Hopes, fears, and rumors: Medical students and the general surgery clerkship. Am J Surg 2021; 222:687-691. [PMID: 34238588 DOI: 10.1016/j.amjsurg.2021.06.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Revised: 06/20/2021] [Accepted: 06/23/2021] [Indexed: 11/20/2022]
Abstract
BACKGROUND Surgical educators have worked to manage the hopes and fears as well as the recurring rumors that plague the surgical clerkship. It is not known if this has effected change over time. METHODS We gathered information on hopes, fears, and rumors during our clerkship orientations from 2017 to 2019 using anonymous polling software with real-time feedback. We analyzed 468 responses using qualitative content analysis. RESULTS Students hoped for practical skills acquisition, self-improvement, and understanding the surgical profession. They feared lack of time and knowledge, burnout, mistreatment, and subjective evaluation. Rumors included negative perceptions of surgical culture work environment, and fear of mistreatment despite clerkship changes intended to allay these fears. CONCLUSION Students starting surgery clerkships hope to gain surgical and clinical skills but concerns about surgical culture and mistreatment appear to remain unchanged despite structural improvements in the clerkship experience. Surgeons should look beyond the clerkship itself to change these perceptions.
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Affiliation(s)
- Charles P Burney
- Department of Surgery, Dartmouth-Hitchcock Medical Center, NH, USA; Geisel School of Medicine at Dartmouth, Hanover, NH, USA
| | - Jenaya L Goldwag
- Department of Surgery, Dartmouth-Hitchcock Medical Center, NH, USA; Geisel School of Medicine at Dartmouth, Hanover, NH, USA
| | - Meredith J Sorensen
- Department of Surgery, Dartmouth-Hitchcock Medical Center, NH, USA; Geisel School of Medicine at Dartmouth, Hanover, NH, USA
| | - Andrew O Crockett
- Department of Surgery, Dartmouth-Hitchcock Medical Center, NH, USA; Geisel School of Medicine at Dartmouth, Hanover, NH, USA.
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Allen RW, Burney CP, Davis A, Henkin J, Kelly J, Judd BG, Ivatury SJ. Deep Sleep and Beeps: Sleep Quality Improvement Project in General Surgery Patients. J Am Coll Surg 2021; 232:882-888. [PMID: 33675989 DOI: 10.1016/j.jamcollsurg.2021.02.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 02/07/2021] [Accepted: 02/08/2021] [Indexed: 01/29/2023]
Abstract
BACKGROUND Poor sleep leads to poor health outcomes. Inpatient sleep disturbance has been studied primarily in the ICU. Minimal research exists on sleep in surgical populations. METHODS We recruited patients undergoing elective, inpatient general surgery procedures. Participants wore Fitbit trackers while inpatient to measure total sleep time (CDC recommendation is 7 or more hours per night). At discharge, patients completed the Richards-Campbell Sleep Questionnaire (RCSQ) to measure inpatient sleep quality. The RCSQ combines 5 domains into a cumulative score (0 to 100); a higher score means better sleep quality. Patients also completed the outpatient Pittsburgh Sleep Quality Index preoperatively and postoperatively. The primary end point was percentage of patients with total sleep score ≥ 50. Secondary outcomes included mean RCSQ domain scores, Fitbit total sleep time, and percentage with Pittsburgh Sleep Quality Index Score indicating poor sleep. RESULTS We included 64 patients (mean ± SD age 55.0 ± 14.1 years). Mean ± SD RCSQ total sleep score was 49 ± 20.5 and 53.1% with total sleep score < 50. Mean ± SD RCSQ domain scores were Awakenings: 40.4 ± 22.8, Sleep Quality: 49.1 ± 27.9, Sleep Latency: 49.2 ± 25.3, Sleep Depth: 50.2 ± 26.5, Returning to Sleep: 55.9 ± 28.1, and Noise Disturbance: 59.1 ± 27.9. On night one, 25 devices (40%) had recorded sleep data due to enough sleep. Mean ± SD total sleep time on night 1 was 4.7 ± 2.8 hours. Mean total sleep time for nights 2, 3, and 4 remained fewer than 7 hours. Percentages for each night that achieved the CDC goal of 7 or more hours were as follows: night one 10.9%, night two 32.8%, night three 35.3%, and night four 27.6%. Per the Pittsburgh Sleep Quality Index, 88.1% of patients were poor sleepers preoperatively and 84.5% were poor sleepers at follow-up (p = 0.6). CONCLUSIONS Elective general surgery patients experience a severe inpatient sleep disturbance, worse than in similarly studied ICU cohorts. This disturbance is driven primarily by nighttime awakenings.
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Affiliation(s)
- Robert W Allen
- Department of Surgery, Dartmouth-Hitchcock Medical Center, Lebanon, NH.
| | - Charles P Burney
- Department of Surgery, Dartmouth-Hitchcock Medical Center, Lebanon, NH
| | - Amy Davis
- Department of Surgery, Dartmouth-Hitchcock Medical Center, Lebanon, NH
| | - Jessica Henkin
- Department of Surgery, Dartmouth-Hitchcock Medical Center, Lebanon, NH
| | - Julia Kelly
- Department of Surgery, Dartmouth-Hitchcock Medical Center, Lebanon, NH
| | - Brooke G Judd
- Department of Surgery, Dartmouth-Hitchcock Medical Center, Lebanon, NH; Sleep Center, Dartmouth-Hitchcock Medical Center, Lebanon, NH; Geisel School of Medicine, Dartmouth College, Lebanon, NH
| | - Srinivas Joga Ivatury
- Department of Surgery, Dartmouth-Hitchcock Medical Center, Lebanon, NH; Geisel School of Medicine, Dartmouth College, Lebanon, NH
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Waseem H, Salih YA, Burney CP, Abel MA, Riblet N, Kim A, Robbins N. Efficacy and Safety of the Telestroke Drip-And-Stay Model: A Systematic Review and Meta-Analysis. J Stroke Cerebrovasc Dis 2021; 30:105638. [PMID: 33540336 DOI: 10.1016/j.jstrokecerebrovasdis.2021.105638] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Revised: 01/10/2021] [Accepted: 01/19/2021] [Indexed: 01/11/2023] Open
Abstract
OBJECTIVES To compare outcomes between two models of acute ischemic stroke care. Namely 1) "drip-and-stay", i.e. IV tissue plasminogen activator (tPA) administered at a spoke hospital in a telestroke network, with the patient remaining at the spoke, versus 2) "drip-and-ship", i.e. tPA administered at a spoke hospital with subsequent patient transfer to a hub hospital, and 3) "hub", i.e. tPA and subsequent treatment at a hub hospital. MATERIALS AND METHODS We performed a systematic review and meta-analysis according to PRISMA guidelines. Literature searches of MEDLINE, Embase, and Cochrane from inception-October 2019 included randomized control trials and observational cohort studies comparing the drip-and-stay model to hub and drip-and-ship models. Outcomes of interest were functional independence (modified Rankin Scale ≤ 1), symptomatic intracranial hemorrhage (sICH), mortality, and length of stay. Pooled effect estimates were calculated using a fixed-effects meta-analysis and random-effects Bayesian meta-analysis. Non-inferiority was calculated using a fixed-margin method. RESULTS Of 2806 unique records identified, 10 studies, totaling 4,164 patients, fulfilled the eligibility criteria. Meta-analysis found no significant difference in functional outcomes (mRS0-1) (6 studies, RR=1.09, 95%CI 0.98-1.22, p=0.123), sICH (8 studies, RR=0.98, 95%CI 0.64-1.51, p=0.942), or 90-day mortality (5 studies, RR=0.98, 95%CI 0.73-1.32, p=0.911, respectively) between patients treated in a drip-and-stay model compared to patients treated in drip-and-ship or hub models. There was no significant heterogeneity in these outcomes. Drip-and-stay outcomes (mRS 0-1, sICH) were non-inferior when compared to the combined group. CONCLUSIONS Our findings indicate that drip-and-stay is non-inferior to current models of drip-and-ship or hub stroke care, and may be as safe and as effective as either.
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Affiliation(s)
- Hena Waseem
- Geisel School of Medicine at Dartmouth, Dartmouth Hitchcock Medical Center, The Dartmouth Institute for Health Policy and Clinical Practice, 1 Medical Center Drive, Lebanon, NH 03766, United States.
| | - Yasir A Salih
- Geisel School of Medicine at Dartmouth, The Dartmouth Institute for Health Policy and Clinical Practice, United States.
| | - Charles P Burney
- Geisel School of Medicine at Dartmouth, Dartmouth Hitchcock Medical Center, The Dartmouth Institute for Health Policy and Clinical Practice, 1 Medical Center Drive, Lebanon, NH 03766, United States.
| | - Mark A Abel
- Geisel School of Medicine at Dartmouth, Dartmouth Hitchcock Medical Center, The Dartmouth Institute for Health Policy and Clinical Practice, 1 Medical Center Drive, Lebanon, NH 03766, United States.
| | - Natalie Riblet
- Geisel School of Medicine at Dartmouth, The Dartmouth Institute for Health Policy and Clinical Practice, United States.
| | - Anthony Kim
- University of California San Francisco Medical Center, United States.
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Major TC, Brant DO, Burney CP, Amoako KA, Annich GM, Meyerhoff ME, Handa H, Bartlett RH. The hemocompatibility of a nitric oxide generating polymer that catalyzes S-nitrosothiol decomposition in an extracorporeal circulation model. Biomaterials 2011; 32:5957-69. [PMID: 21696821 DOI: 10.1016/j.biomaterials.2011.03.036] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2011] [Accepted: 03/12/2011] [Indexed: 11/29/2022]
Abstract
Nitric oxide (NO) generating (NOGen) materials have been shown previously to create localized increases in NO concentration by the catalytic decomposition of blood S-nitrosothiols (RSNO) via copper (Cu)-containing polymer coatings and may improve extracorporeal circulation (ECC) hemocompatibility. In this work, a NOGen polymeric coating composed of a Cu⁰-nanoparticle (80 nm)-containing hydrophilic polyurethane (SP-60D-60) combined with the intravenous infusion of an RSNO, S- nitroso-N-acetylpenicillamine (SNAP), is evaluated in a 4 h rabbit thrombogenicity model and the anti-thrombotic mechanism is investigated. Polymer films containing 10 wt.% Cu⁰-nanoparticles coated on the inner walls of ECC circuits are employed concomitantly with systemic SNAP administration (0.1182 μmol/kg/min) to yield significantly reduced ECC thrombus formation compared to polymer control + systemic SNAP or 10 wt.% Cu NOGen + systemic saline after 4 h blood exposure (0.4 ± 0.2 NOGen/SNAP vs 4.9 ± 0.5 control/SNAP or 3.2 ± 0.2 pixels/cm² NOGen/saline). Platelet count (3.9 ± 0.7 NOGen/SNAP vs 1.8 ± 0.1 control/SNAP or 3.0 ± 0.2 × 10⁸/ml NOGen/saline) and plasma fibrinogen levels were preserved after 4 h blood exposure with the NOGen/SNAP combination vs either the control/SNAP or the NOGen/saline groups. Platelet function as measured by aggregometry (51 ± 9 NOGen/SNAP vs 49 ± 3% NOGen/saline) significantly decreased in both the NOGen/SNAP and NOGen/saline groups while platelet P-selectin mean fluorescence intensity (MFI) as measured by flow cytometry was not decreased after 4 h on ECC to ex vivo collagen stimulation (26 ± 2 NOGen/SNAP vs 29 ± 1 MFI baseline). Western blotting showed that fibrinogen activation as assessed by Aγ dimer expression was reduced after 4 h on ECC with NOGen/SNAP (68 ± 7 vs 83 ± 3% control/SNAP). These results suggest that the NOGen polymer coating combined with SNAP infusion preserves platelets in blood exposure to ECCs by attenuating activated fibrinogen and preventing platelet aggregation. These NO-mediated platelet changes were shown to improve thromboresistance of the NOGen polymer-coated ECCs when adequate levels of RSNOs are present.
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Affiliation(s)
- Terry C Major
- Department of Surgery, University of Michigan Medical Center, Ann Arbor, MI 48109, USA.
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