Race, Insurance, and Sex-Based Disparities in Access to High-Volume Centers for Pancreatectomy

BACKGROUND

With a large body of literature demonstrating positive volume-outcome relationships for most major operations, minimum volume requirements have been suggested for concentration of cases to high-volume centers (HVCs). However, data are limited regarding disparities in access to these hospitals for pancreatectomy patients.

METHODS

The 2005-2018 National Inpatient Sample (NIS) was queried for all elective adult hospitalizations for pancreatectomy. Hospitals performing more than 20 annual cases were classified as HVCs. Mixed-multivariable regression models were developed to characterize the impact of demographic factors and case volume on outcomes of interest.

RESULTS

Of an estimated 127,527 hospitalizations, 79.8% occurred at HVCs. Patients at these centers were more frequently white (79.0 vs 70.8%; p < 0.001), privately insured (39.4 vs 34.2%; p < 0.001), and within the highest income quartile (30.5 vs 25.0%; p < 0.001). Adjusted analysis showed that operations performed at HVCs were associated with reduced odds of in-hospital mortality (adjusted odds ratio [AOR], 0.43; 95% confidence interval [CI], 0.34-0.55), increased odds of discharge to home (AOR, 1.17; 95% CI, 1.04-1.30), shorter hospital stay (β, -0.81 days; 95% CI, -1.2 to -0.40 days), but similar costs. Patients who were female (AOR, 0.88; 95% CI, 0.79-0.98), non-white (black: AOR, 0.66; 95% CI, 0.59-0.75; Hispanic: AOR, 0.56; 95% CI, 0.47-0.66; reference, white), insured by Medicaid (AOR, 0.63; 95% CI, 0.56-0.72; reference, private), and within the lowest income quartile (AOR, 0.73; 95% CI, 0.59-0.90; reference, highest) had decreased odds of treatment at an HVC.

CONCLUSIONS

For those undergoing pancreatectomies, HVCs realize superior clinical outcomes but treat lower proportions of female, non-white, and Medicaid populations. These findings may have implications for improving access to high-quality centers.

Comparison of Diversion Strategies for Management of Acute Complicated Diverticulitis in a US Nationwide Cohort

IMPORTANCE

Diverticulitis of the colon is an increasingly prevalent disease with significant implications for patient quality of life and health system resource expenditure. Although several randomized clinical trials and meta-analyses of Hartman procedure (HP) and primary anastomosis and proximal diversion (PAPD) have found surgical equipoise, questions regarding the relative performance of these treatments when applied broadly remain.

OBJECTIVE

To examine use of and outcomes after urgent sigmoid colectomy with end colostomy (ie, HP) vs PAPD in management of complicated diverticulitis.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cross-sectional study was a multicenter, population-based examination of inpatient hospitalizations, not including long-term rehabilitation facilities, using data from the 2014 to 2017 Nationwide Readmissions Database. It was performed from November 2020 to January 2021. Included patients were adults admitted with acute diverticulitis requiring HP or PAPD within 48 hours of admission.

EXPOSURES

Undergoing HP vs PAPD.

MAIN OUTCOMES AND MEASURES

Inverse probability treatment analysis was used to compare outcomes, including index mortality, composite complications (ie, neurologic, infectious, and cardiovascular complications), length of stay, and readmissions within 90 days.

RESULTS

During the study period, an estimated 1 072 395 adults (615 954 [57.4%] women; median [IQR] age, 64 [52-76] years) required nonelective hospitalization for acute colonic diverticulutus. A total of 34 126 patients required diversion, with 32 326 patients (94.7%) undergoing HP and 1800 patients (5.3%) undergoing PAPD within 48 hours of admission. Patients undergoing PAPD had a decreased median (IQR) age (60 [51-70] years vs 65 [54-74] years; P < .001) and decreased rates of end organ dysfunction (520 patients [28.9%] vs 11 514 patients [35.6%]; P < .001). In inverse probability treatment weight analysis, the odds of mortality (adjusted odds ratio [aOR], 0.63; 95% CI, 0.32-1.40), complications (aOR, 0.86; 95% CI, 0.66-1.13), and nonhome discharge (aOR 1.15; 95% CI, 0.83-1.60) were similar for PAPD compared with HP. Among 1772 patients who underwent PAPD and survived index hospitalization, there was an increased incidence of 90-day readmission compared with 30 851 patients who underwent HP and survived index hospitalization (393 patients [22.2%] vs 4384 patients [14.2%]; P < .001) with increased hazard of ostomy reversal (hazard ratio, 1.46; 95% CI, 1.08-1.99).

CONCLUSIONS AND RELEVANCE

This study found that the use of PAPD was associated with comparable index hospitalization outcomes vs use of HP, while readmission rate and ostomy risk were statistically significantly increased among patients who underwent PAPD compared with patients who underwent HP. These findings suggest that further delineation of criteria for appropriate application of PAPD in the urgent setting are warranted.

A kinematic model-based analysis framework for 3D Cine-DENSE-validation with an axially compressed gel phantom and application in sheep before and after antero-apical myocardial infarction

PURPOSE

Myocardial strain is increasingly used to assess left ventricular (LV) function. Incorporation of LV deformation into finite element (FE) modeling environment with subsequent strain calculation will allow analysis to reach its full potential. We describe a new kinematic model-based analysis framework (KMAF) to calculate strain from 3D cine-DENSE (displacement encoding with stimulated echoes) MRI.

METHODS

Cine-DENSE allows measurement of 3D myocardial displacement with high spatial accuracy. The KMAF framework uses cine cardiovascular magnetic resonance (CMR) to facilitate cine-DENSE segmentation, interpolates cine-DENSE displacement, and kinematically deforms an FE model to calculate strain. This framework was validated in an axially compressed gel phantom and applied in 10 healthy sheep and 5 sheep after myocardial infarction (MI).

RESULTS

Excellent Bland-Altman agreement of peak circumferential (E_cc ) and longitudinal (E_ll ) strain (mean difference = 0.021 ± 0.04 and -0.006 ± 0.03, respectively), was found between KMAF estimates and idealized FE simulation. E_rr had a mean difference of -0.014 but larger variation (±0.12). Cine-DENSE estimated end-systolic (ES) E_cc , E_ll and E_rr exhibited significant spatial variation for healthy sheep. Displacement magnitude was reduced on average by 27%, 42%, and 56% after MI in the remote, adjacent and MI regions, respectively.

CONCLUSIONS

The KMAF framework allows accurate calculation of 3D LV E_cc and E_ll from cine-DENSE.

Outcomes and resource use for liver transplantation in the United States: Insights from the 2009-2017 National Inpatient Sample

INTRODUCTION

Liver transplantation (LT) is a life-saving treatment for end-stage liver disease patients that requires significant resources. We used national data to evaluate LT outcomes and factors associated with hospital resource use.

METHODS

Using the National Inpatient Sample, we identified all patients undergoing LT from 2009 to 2017 and defined high-resource use (HRU) as having costs ≥ 90th percentile. Hierarchical regression models were used to assess factors associated with length of stay (LOS) and HRU.

RESULTS

Over the study period, approximately 53,000 patients underwent LT, increasing from 5,582 in 2009 to 7,095 in 2017 (nptrend < 0.001). Morbidity and mortality were 42.2% and 3.9%, respectively, with a median post-LT LOS of 10 days. Hospitalization costs increased from $106,866 to $145,868 (nptrend < 0.001). Acute kidney injury (β:4.7 days, P < .001) and end-stage renal disease (ESRD) with dialysis (β:4.3 days, P < .001) were associated with greater LOS while the Northeast region (AOR:5.2, P < .001), ESRD with dialysis (AOR:3.4, P < .001), heart failure (AOR:2.5, P < .001), and fulminant liver disease (AOR:1.8, P = .01) were associated with HRU.

CONCLUSION

The cost of LT has increased over time. Renal dysfunction, regional practice patterns, and patient acuity were associated with greater resource use. Transplanting patients before health deterioration may help contain costs, mitigate resource use, and improve LT outcomes.

National Use and Short-term Outcomes of Video and Robot-Assisted Thoracoscopic Thymectomies

BACKGROUND

Transsternal open thymectomy has long been the most widely used approach for thymectomy, but recent decades have seen the introduction of minimally invasive surgery (MIS), such as video-assisted thoracoscopic surgery (VATS) and robot-assisted thoracoscopic surgery (RATS) thymectomy. This retrospective cohort study provides a national comparison of trends, outcomes, and resource utilization of open, VATS, and RATS thymectomy.

METHODS

Admissions for thymectomies from 2008 to 2014 were identified in the National Inpatient Sample. Patients were identified as undergoing open, VATS, or RATS thymectomy. Propensity score-matched analyses were used to compare overall complication rates, length of stay (LOS), and cost of VATS and RATS thymectomies.

RESULTS

An estimated 23,087 patients underwent thymectomy during the study period: open in 16,025 (69%) and MIS in 7217 (31%). Of the MIS cohort, 4119 (18%) underwent VATS and 3097 (13%) underwent RATS. Performance of RATS and VATS thymectomy increased while that of open thymectomy declined. Baseline characteristics between VATS and RATS were similar, except more women underwent VATS thymectomy. No differences in LOS or overall complication rates were appreciable in this study. VATS was associated with the lowest cost of the 3 approaches.

CONCLUSIONS

Our findings demonstrate the increasing adoption of MIS and declining use of the open surgical approach for thymectomy. There are no differences in overall complication rates between RATS and VATS thymectomy, but RATS is associated with greater cost and lower cardiac complication rates.

Factors associated with high-cost hospitalizations in elderly ovarian cancer patients

OBJECTIVE

To characterize factors associated with high-cost inpatient admissions for ovarian cancer.

METHODS

Operative hospitalizations for ovarian cancer patients ≥65 years of age were identified using the 2010-2017 National Inpatient Sample. Admissions with high-cost were defined as those incurring ≥90th percentile of hospitalization costs each year, while the remainder were considered low-cost. Multivariable logistic regression models were developed to assess independent predictors of being in the high-cost cohort.

RESULTS

During the study period, an estimated 58,454 patients met inclusion criteria. 5827 patient admissions (9.98%) were classified as high-cost. Median hospitalization cost for this high-cost group was $55,447 (interquartile range (IQR) $46,744-$74,015) compared to $16,464 (IQR $11,845-$23,286, p < 0.001) for the low-cost group. Patients with high-cost admissions were more likely to have received open (adjusted odds ratio (AOR) 2.23, 1.31-3.79) or extended (AOR 5.64, 4.79-6.66) procedures and be admitted non-electively (AOR 3.32, 2.74-4.02). Being in the top income quartile (AOR 1.77, 1.39-2.27) was also associated with high-cost. Age and hospital factors, including bed size and volume of gynecologic oncology surgery, did not affect cost group.

CONCLUSION

High-cost ovarian cancer admissions were three times more expensive than low-cost admissions. Fewer open and extended procedures with subsequently shorter lengths of stay may have contributed to decreasing inpatient costs over the study period. In this cohort of patients largely covered by Medicare, clinical factors outweigh socioeconomic factors as cost drivers. Understanding the relationship of disease-specific and social factors to cost will be important in informing future value-based quality improvement efforts in gynecologic cancer care.

Predictors and In-Hospital Outcomes Among Patients Using a Single Versus Bilateral Mammary Arteries in Coronary Artery Bypass Grafting

The benefit of bilateral mammary artery (BIMA) use during coronary artery bypass grafting (CABG) continues to be debated. This study examined nationwide trends in BIMA use and factors influencing its utilization. Using the National Inpatient Sample, adults undergoing isolated multivessel CABG between 2005 and 2015 were identified and stratified based on the use of a single mammary artery or BIMA. Regression models were fit to identify patient and hospital level predictors of BIMA use and characterize the association of BIMA on outcomes including sternal infection, mortality, and resource utilization. An estimated 4.5% (n = 60,698) of patients underwent CABG with BIMA, with a steady increase from 3.8% to 5.0% over time (p<0.001). Younger age, male gender, and elective admission, were significant predictors of BIMA use. Moreover, private insurance was associated with higher odds of BIMA use (adjusted odds ratio 1.24) compared with Medicare. BIMA use was not a predictor of postoperative sternal infection, in-hospital mortality, or hospitalization costs. Overall, BIMA use remains uncommon in the United States despite no significant differences in acute postoperative outcomes. Several patient, hospital, and socioeconomic factors appear to be associated with BIMA utilization.

Impact of Early Tracheostomy on Outcomes After Cardiac Surgery: A National Analysis

BACKGROUND

Despite evidence supporting its early use in respiratory failure, tracheostomy is often delayed in cardiac surgical patients given concerns for sternal infection. This study assessed national trends in tracheostomy creation among cardiac patients and evaluated the impact of timing to tracheostomy on postoperative outcomes.

METHODS

We used the 2005 to 2015 National Inpatient Sample to identify adults undergoing coronary revascularization or valve operations and categorized them based on timing of tracheostomy: early tracheostomy (ET) (postoperative days 1-14) and delayed tracheostomy (DT) (postoperative days 15-30). Temporal trends in the timing of tracheostomy were analyzed, and multivariable models were created to compare outcomes.

RESULTS

An estimated 33,765 patients (1.4%) required a tracheostomy after cardiac operations. Time to tracheostomy decreased from 14.8 days in 2005 to 13.9 days in 2015, sternal infections decreased from 10.2% to 2.9%, and in-hospital death also decreased from 23.3% to 15.9% over the study period (all P for trend <.005). On univariate analysis, the ET cohort had a lower rate of sternal infection (5.2% vs 7.8%, P < .001), in-hospital death (16.7% vs 22.9%, P < .001), and length of stay (33.7 vs 43.6 days, P < .001). On multivariable regression, DT remained an independent predictor of sternal infection (adjusted odds ratio, 1.35; P < .05), in-hospital death (odds ratio, 1.36; P < .001), and length of stay (9.1 days, P < .001), with no difference in time from tracheostomy to discharge between the 2 cohorts (P = .40).

CONCLUSIONS

In cardiac surgical patients, ET yielded similar postoperative outcomes, including sternal infection and in-hospital death. Our findings should reassure surgeons considering ET in poststernotomy patients with respiratory failure.

Trends in Mortality and Costs of Pediatric Extracorporeal Life Support

BACKGROUND

Extracorporeal life support (ECLS) has been used for >30 years as a life-sustaining therapy in critically ill patients for a variety of indications. In the current study, we aimed to examine trends in use, mortality, length of stay (LOS), and costs for pediatric ECLS hospitalizations.

METHODS

We performed a retrospective cohort study of pediatric patients (between the ages of 28 days and <21 years) on ECLS using the 2008-2015 National Inpatient Sample, the largest all-payer inpatient hospitalization database generated from hospital discharges. Nonparametric and Cochran-Armitage tests for trend were used to study in-hospital mortality, LOS, and hospitalization costs.

RESULTS

Of the estimated 5847 patients identified and included for analysis, ECLS was required for respiratory failure (36.4%), postcardiotomy syndrome (25.9%), mixed cardiopulmonary failure (21.7%), cardiogenic shock (13.1%), and transplanted graft dysfunction (2.9%). The rate of ECLS hospitalizations increased 329%, from 11 to 46 cases per 100 000 pediatric hospitalizations, from 2008 to 2015 (P < .001). Overall mortality decreased from 50.3% to 34.6% (P < .001). Adjusted hospital costs increased significantly ($214 046 ± 11 822 to 324 841 ± 25 621; P = .002) during the study period despite a stable overall hospital LOS (46 ± 6 to 44 ± 4 days; P = .94).

CONCLUSIONS

Use of ECLS in pediatric patients has increased with substantially improved ECLS survival rates. Hospital costs have increased significantly despite a stable LOS in this group. Dissemination of this costly yet life-saving technology warrants ongoing analysis of use trends to identify areas for quality improvement.

Readmission and Resource Use After Robotic-Assisted versus Open Pancreaticoduodenectomy: 2010-2017

BACKGROUND

Unplanned rehospitalization is considered an adverse quality of care indicator. Minimally invasive operations carry the potential to reduce resource use while enhancing recovery. Robotic-assisted pancreaticoduodenectomy (RAPD) has been used to improve outcomes of its morbid open counterpart. We sought to identify factors associated with readmission between RAPD and open pancreaticoduodenectomy (OPD).

MATERIALS AND METHODS

We used the 2010-17 National Readmissions Database to identify adults who underwent RAPD or OPD. The primary outcome was 30-day readmission. Secondary outcomes included readmission diagnosis: index, readmission, and total (index + readmission) length of stay, costs, and mortality.

RESULTS

Of an estimated 84,036 patients undergoing pancreaticoduodenectomy, 96.9% survived index hospitalization. Frequency of both RAPD and OPD increased during the study period with similar mortality (2.5% versus 3.2%, P = 0.46). Compared with OPD, RAPD was not an independent predictor of 30-day readmission (adjusted odds ratio (AOR): 1.0, P = 0.98). Disposition with home health care (AOR: 1.1, P < 0.001) or to a skilled nursing facility (AOR: 1.5, P < 0.001) was significantly associated with increased 30-day readmission.

CONCLUSIONS

Readmission after pancreaticoduodenectomy is common, regardless of surgical approach. Although RAPD saves in-patient days on index admission, readmission rates and length of stay are similar between the two modalities. Neither RAPD nor OPD is a risk factor for readmission, highlighting the complexity of pancreaticoduodenectomy, with complications that may result from factors independent of the operative approach.

National Trends in Readmission and Resource Utilization After Pancreatectomy in the United States

INTRODUCTION

Pancreatectomy is a complex operation that has been associated with excess morbidity and mortality. Although acute index outcomes have been characterized, there are limited data available on nonelective readmission after pancreatic surgery. We sought to identify factors associated with 30-day and 30- to 90-day readmission after pancreatectomy.

MATERIAL AND METHODS

We utilized the National Readmissions Database between 2010 and 2016 to identify adults who underwent a pancreatectomy. The primary outcomes were 30-day (30DR) and 30- to 90-day (90DR) readmission. Secondary outcomes included nonelective readmission trends, diagnosis, length of stay, charges, and mortality.

RESULTS

Of an estimated 130,267 subjects undergoing pancreatectomy, 97% survived index hospitalization. Eighteen percent of patients had nonelective 30DR while 5.6% experienced 90DR. Readmission at the two time points remained stable during the study period. After adjusting for institution, pancreatectomy volume, mortality (2.0% versus 4.9%, P < 0.001), 30DR length of stay (7.3 d versus 7.8 d, P < 0.001), and 90DR rates (6.9% versus 8.1%, P = 0.003) were significantly decreased at high-volume pancreatectomy centers compared to low-volume hospitals. Discharge to a skilled nursing facility (AOR: 1.52) or with home health care (AOR: 1.2) was associated with 30DR (P < 0.001). Patients undergoing total pancreatectomy (AOR: 1.3) or those with a substance use disorder (AOR: 1.4) among others were associated with 90DR (P ≤ 0.01).

CONCLUSIONS

Readmissions are common and costly after pancreatectomy. Approximately 20% of patients experience readmission within 30 d. 30DR and 90DR rates remained stable during the study. Pancreatectomy at a high-volume center was associated with decreased mortality and 90DR. The present analysis confirms associations between pancreatectomy volume, postsurgical complications, comorbidities, and readmission.

Impact of Hospital Volume on Outcomes of Elective Pneumonectomy in the United States

BACKGROUND

Despite advances in surgical technique and perioperative management, pneumonectomy remains associated with significant morbidity and mortality. The purpose of this study was to examine the impact of annual institutional volume of anatomic lung resections on outcomes after elective pneumonectomy.

METHODS

We evaluated all patients who underwent elective pneumonectomy from 2005 to 2014 in the National Inpatient Sample. Patients less than 18 years of age, or with trauma-related diagnoses, mesothelioma, or a nonelective admission were excluded. Hospitals were divided into volume quartiles based on annual institutional anatomic lung resection caseload. We studied the effect of institutional volume on inhospital mortality, complications, and failure to rescue, as well as costs and length of stay.

RESULTS

During the study period, an estimated 22,739 patients underwent pneumonectomy, with a reduction in national mortality from 7.9% to 5.5% (P trend = .045). Compared with the highest volume centers, operations performed at the lowest volume hospitals were associated with 1.74 increased odds of mortality (95% confidence interval, 1.14 to 2.66). Despite similar odds of postoperative complications, low volume hospital status was associated with increased failure to rescue rates (18.3% vs 12.7%, P = .024) and adjusted odds of mortality (1.70; 95% confidence interval, 1.09 to 2.64) after any complication.

CONCLUSIONS

High volume hospital status is strongly associated with reduced mortality and failure to rescue rates after pneumonectomy. Efforts to centralize care or disseminate best practices may lead to improved national outcomes for this high-risk procedure.

Impact of interhospital transfer on clinical outcomes and costs of extracorporeal life support

BACKGROUND

The impact of interhospital transfers for extracorporeal life support have not been studied in large datasets. The present study sought to determine the impact of such patient transfers on survival, complications, and hospitalization costs.

METHODS

The 2010 to 2016 database of the National Inpatient Sample was used to identify all adults who underwent extracorporeal life support. Patients were categorized based on whether or not they were transferred to another facility. Trend analysis and multivariable models were used to characterize the impact of inter hospital transfer on in-hospital mortality, complications, duration of stay, and costs.

RESULTS

Of an estimated 29,298 extracorporeal life support hospitalizations during the study period, 36.8% were transferred from an outside facility. Extracorporeal life support hospitalizations experienced a 7-fold increase with no difference in mortality between transferred and not transferred cohorts in 2016 (4.79% vs 4.79%, P = .97). Mortality rates were less for patients transferred to high volume centers compared to low volume hospitals (48.7% vs 51.6%, P < .001). Transfer to a low volume hospital for cardiogenic shock was associated with greater odds of mortality (adjusted odds Rratio: 2.25, confidence interval 1.01-5.03).

CONCLUSION

Utilization of extracorporeal life support in both transferred and not transferred patients has statistically significantly increased with a decrement in mortality for those transferred. Survival in the transferred cohort is strongly associated with extracorporeal life support procedure volume of the center and this must be taken into account when considering extracorporeal life support transfer.

Myocardial injection of a thermoresponsive hydrogel with reactive oxygen species scavenger properties improves border zone contractility

The decrease in contractility in myocardium adjacent (border zone; BZ) to a myocardial infarction (MI) is correlated with an increase in reactive oxygen species (ROS). We hypothesized that injection of a thermoresponsive hydrogel, with ROS scavenging properties, into the MI would decrease ROS and improve BZ function. Fourteen sheep underwent antero-apical MI. Seven sheep had a comb-like copolymer synthesized from N-isopropyl acrylamide (NIPAAm) and 1500 MW methoxy poly(ethylene glycol) methacrylate, (NIPAAm-PEG1500), injected (20 × 0.5 mL) into the MI zone 40 min after MI (MI + NIPAAm-PEG1500) and seven sheep were MI controls. Cardiac MRI was performed 2 weeks before and 6 weeks after MI + NIPAAm-PEG1500. BZ wall thickness at end systole was significantly higher for MI + NIPAAm-PEG1500 (12.32 ± 0.51 mm/m² MI + NIPAAm-PEG1500 vs. 9.88 ± 0.30 MI; p = .023). Demembranated muscle force development for BZ myocardium 6 weeks after MI was significantly higher for MI + NIPAAm-PEG1500 (67.67 ± 2.61 mN/m² MI + NIPAAm-PEG1500 vs. 40.53 ± 1.04 MI; p < .0001) but not significantly different from remote myocardium or BZ or non-operated controls. Levels of ROS in BZ tissue were significantly lower in the MI + NIPAAm-PEG1500 treatment group (hydroxyl p = .0031; superoxide p = .0182). We conclude that infarct injection of the NIPAAm-PEG1500 hydrogel with ROS scavenging properties decreased ROS and improved contractile protein function in the border zone 6 weeks after MI.

National Analysis of Coronary Artery Bypass Grafting in Autoimmune Connective Tissue Disease

BACKGROUND

Autoimmune connective tissue diseases (CTDs) are associated with accelerated atherosclerosis and inflammation, while often requiring immunosuppression. Large-scale outcomes of coronary artery bypass graft (CABG) surgery in this population have not been reported thus far. This study characterized trends in use of CABG in patients with CTDs and the impact of the disease on mortality, in-hospital complications, length of stay, and costs.

METHODS

The 2005 to 2015 National Inpatient Sample was used to identify all adult patients undergoing isolated CABG. The CTDs cohort included rheumatoid arthritis, lupus erythematosus, and antiphospholipid syndrome (APLS), among others. Hierarchical multivariable logistic models were used to calculate the independent impact of CTDs on clinical outcomes and costs.

RESULTS

Of an estimated 2,101,591 patients, 41,567 (1.8%) were diagnosed with CTDs (rheumatoid arthritis, 58%; systemic lupus erythematosus, 12%; APLS, 11%) Although the overall annual use of CABG decreased, the proportion of patients with CTDs receiving the operation significantly increased. After adjusting for patient and hospital characteristics, CTDs were not associated with increased mortality (adjusted odds ratio [AOR], 0.91; P = .34) but were protective against cardiovascular (AOR, 0.92; P < .003), neurologic (AOR, 0.81; P = .01), and infectious (AOR, 0.80; P = .01) complications. The diagnosis of CTDs was also predictive of reduced length of hospital stay (β-coefficient = -0.40; P < .001) and costs (β-coefficient, -$1200; P = .01). On subgroup analysis patients with APLS had significantly increased odds of mortality (AOR, 1.5) and increased renal (AOR, 1.3), infectious (AOR, 1.7), and thromboembolic (AOR, 4.3) complications (all P < .05).

CONCLUSIONS

CABG in patients with CTDs provides acceptable outcomes and paradoxically improved resource use. However CABG in patients with APLS warrants careful consideration given inferior outcomes.

Assessment of Differential Pressures in Chest Drainage Systems: Is What You See What You Get?

BACKGROUND

Dry-suction chest drainage systems are used to achieve proper drainage of the pleural space after cardiothoracic operations. Data on the actual intrapleural pressure during the use of these systems is lacking. The present study was performed to evaluate pressure differences across the circuit using an ex vivo model.

METHODS

An ex vivo apparatus coupled to a hospital-grade pleural drainage system was devised to provide calibrated levels of suction and air leak. Simultaneous pressure measurements were obtained at the system outlet and the simulated patient entry site. Trials were conducted with increasing levels of water between the patient and drainage modules at various levels of suction and leak pressures. Signals were recorded at 100 Hz and analyzed using two-way ANOVA.

RESULTS

With no obstruction, the drainage system provided precise levels of negative pressure at the patient level (10-40 cm H₂O). Addition of fluid in the drainage tubing caused significant differences in transmitted suction (P < 0.001). With increasing air leakage and fluid volume, the pressure differential between the system and patient increased significantly (1.14 to 36.69 cm H₂O, P < 0.001). In the off-suction setting, increasing levels of obstruction to 22 cm of water led to development of positive intrapleural pressures (2.6 to 11.1 cm H₂O, P < 0.001).

CONCLUSIONS

While commercially available chest drainage systems are able to provide predictable levels of suction at the device, intrapleural pressures can be highly variable and depend on complete patency of connecting tubes. Systems capable of modulating the level of suction based on actual intrapleural pressures may enhance recovery after procedures requiring tube thoracotomy.

Comparison of Frequency of Late Gastrointestinal Bleeding With Transcatheter Versus Surgical Aortic Valve Replacement

Improvements in technology and operator experience have led to exponential growth of transcatheter aortic valve implantation (TAVI) programs. Late bleeding complications were recently highlighted after TAVI with a high impact on morbidity. The purpose of the present study was to assess the incidence and financial impact of late Gastrointestinal (GI) bleeding after TAVI, and compare with the surgical cohort. Retrospective analysis of the National Readmissions Database was performed from January 2011 to December 2014, and patients who underwent TAVI or surgical aortic valve replacement (SAVR) were identified. Incidence of readmission with a diagnosis of GI bleeding was utilized as the primary end point. Overall, 43,357 patients were identified who underwent TAVI, whereas 310,013 patients underwent SAVR. Compared with SAVR, TAVI patients were older (81 vs 68y, p < 0.001), more women (48% vs 36%, p < 0.001), and had higher Elixhauser Comorbidity Index (6 vs 5, p < 0.001). Hospital stay was shorter with TAVI (5 vs 8 days, p < 0.001), but raw in-hospital mortality rates were similar (4.2% vs 3.8%, p = 0.022). In the TAVI cohort, 3.3% of patients were rehospitalized for GI bleeding compared with 1.5% of the SAVR cohort (p < 0.001). Average time to bleeding readmission was similar between cohorts (92 vs 84 days, p = 0.049). After multivariable adjustment, TAVI remained significantly associated with readmissions for GI bleeding compared with SAVR Adjusted Odds Ratio (AOR 1.54 [1.38 to 1.71], p < 0.001). In this national cohort study, TAVI was associated with more frequent readmissions for late GI bleeding compared with SAVR. In conclusion, strategies to reduce late GI bleeding may serve as important targets for improvement in overall quality of care.

Readmissions after Ileostomy Creation Using a Nationwide Database

Readmissions occur frequently in patients undergoing ostomy creation, ranging from 12 per cent to more than 30 per cent. The objective of this study was to compare the reasons for early versus intermediate readmissions after surgical procedures involving formation of ileostomies at a national level. Patients receiving a new ileostomy were identified in the 2010 to 2014 Nationwide Readmission Database. Patients were categorized into Early, Intermediate, and Late cohorts (0–7, 8–30, 31–90 days, respectively), based on discharge-to-readmission interval. Of the 76,590 patients undergoing ileostomy creation, 28 per cent were nonelectively rehospitalized within 90 days after discharge: 10 per cent Early, 12 per cent Intermediate, and 7 per cent Late. Compared with the Intermediate cohort, the Early readmissions were more frequently because of anastomotic complications (20% vs 12%, P < 0.001) and gastrointestinal obstruction (10% vs 5%, P < 0.001), whereas Intermediate readmissions were because of renal failure (17% vs 9%, P < 0.001). In the Late group, the most common reason for readmission was renal failure (14%), followed by anastomotic complications (11%), and stoma reversal (8%). In this nationwide study, all-cause 90-day non-elective readmissions after ileostomy procedures occurred in nearly 30 per cent of patients. Although early rehospitalizations were mainly because of surgical complications and gastrointestinal complications, late readmissions were because of ileostomy reversal.

Racial Disparities in the Incidence of Pulmonary Embolism after Colectomy

Disparities in the incidence of pulmonary embolism (PE) based on racial and socioeconomic factors remain ill-defined. The present study evaluated the impact of race and hospital characteristics on rates of PE for all adult colectomy patients in the 2005 to 2014 Nationwide Inpatient Sample. Hospitals were designated as high-burden hospitals (HBHs) or low-burden hospitals of underinsured payers. Chi-squared tests of trend and multivariable regression adjusting for patient and hospital characteristics were performed. Of the 2,737,977 adult patients who underwent colectomy in the study period, 79 per cent were White, 10 per cent Black, and 7 per cent Hispanic. The annual rate of PE increased from 0.6 per cent in 2005 to 0.95 per cent in 2014 ( P < 0.0001). Black patients had significantly higher incidence of PE than Whites (1.5% vs 0.9%, P < 0.001) and Hispanics (1.5% vs 0.8%, P < 0.001). Colectomy at HBHs was also associated with significantly higher rates of PE (1% vs 0.86%, P < 0.001). After adjusting for baseline differences, colectomy at HBHs (odds ratio 1.14, 95% confidence interval 1.02–1.27, P = 0.02) and Black race (odds ratio 1.4, 95% confidence interval 1.26–1.66, P < 0.001) were independent predictors of PE. In this national study of colectomy patients, Black patients experienced a disproportionate burden of postoperative PE. Further investigation into the causes and prevention of PE in vulnerable populations may identify targets for surgical quality improvement.

Racial Disparities in the Incidence of Pulmonary Embolism after Colectomy

Disparities in the incidence of pulmonary embolism (PE) based on racial and socioeconomic factors remain ill-defined. The present study evaluated the impact of race and hospital characteristics on rates of PE for all adult colectomy patients in the 2005 to 2014 Nationwide Inpatient Sample. Hospitals were designated as high-burden hospitals (HBHs) or low-burden hospitals of underinsured payers. Chi-squared tests of trend and multivariable regression adjusting for patient and hospital characteristics were performed. Of the 2,737,977 adult patients who underwent colectomy in the study period, 79 per cent were White, 10 per cent Black, and 7 per cent Hispanic. The annual rate of PE increased from 0.6 per cent in 2005 to 0.95 per cent in 2014 (P < 0.0001). Black patients had significantly higher incidence of PE than Whites (1.5% vs 0.9%, P < 0.001) and Hispanics (1.5% vs 0.8%, P < 0.001). Colectomy at HBHs was also associated with significantly higher rates of PE (1% vs 0.86%, P < 0.001). After adjusting for baseline differences, colectomy at HBHs (odds ratio 1.14, 95% confidence interval 1.02-1.27, P = 0.02) and Black race (odds ratio 1.4, 95% confidence interval 1.26-1.66, P < 0.001) were independent predictors of PE. In this national study of colectomy patients, Black patients experienced a disproportionate burden of postoperative PE. Further investigation into the causes and prevention of PE in vulnerable populations may identify targets for surgical quality improvement.

Readmissions after Ileostomy Creation Using a Nationwide Database

Readmissions occur frequently in patients undergoing ostomy creation, ranging from 12 per cent to more than 30 per cent. The objective of this study was to compare the reasons for early versus intermediate readmissions after surgical procedures involving formation of ileostomies at a national level. Patients receiving a new ileostomy were identified in the 2010 to 2014 Nationwide Readmission Database. Patients were categorized into Early, Intermediate, and Late cohorts (0-7, 8-30, 31-90 days, respectively), based on discharge-to-readmission interval. Of the 76,590 patients undergoing ileostomy creation, 28 per cent were nonelectively rehospitalized within 90 days after discharge: 10 per cent Early, 12 per cent Intermediate, and 7 per cent Late. Compared with the Intermediate cohort, the Early readmissions were more frequently because of anastomotic complications (20% vs 12%, P < 0.001) and gastrointestinal obstruction (10% vs 5%, P < 0.001), whereas Intermediate readmissions were because of renal failure (17% vs 9%, P < 0.001). In the Late group, the most common reason for readmission was renal failure (14%), followed by anastomotic complications (11%), and stoma reversal (8%). In this nationwide study, all-cause 90-day nonelective readmissions after ileostomy procedures occurred in nearly 30 per cent of patients. Although early rehospitalizations were mainly because of surgical complications and gastrointestinal complications, late readmissions were because of ileostomy reversal.

Impact of New-Onset Postoperative Depression on Readmission Outcomes After Surgical Coronary Revascularization

BACKGROUND

Depression affects between 10% and 40% of cardiac surgery patients and is associated with significantly worse outcomes. The incidence and impact of new-onset depression beyond acute follow-up remain ill-defined. The present study aimed to evaluate the incidence, risk factors, and prognostic implication of depression on 90-d readmission rates after coronary artery bypass grafting (CABG) surgery.

METHODS

A retrospective cohort study was performed identifying adult patients without prior depression who underwent CABG surgery using the 2010-2014 National Readmissions Database. CABG patients who were readmitted more than 2 wk but within 90 d of discharge were categorized based on the presence of new-onset depression. Association between the development of new-onset depression and rehospitalization were morbidity, mortality, costs, and length of stay (LOS) and were examined using multivariable regression.

RESULTS

During the study period, 1,001,945 patients underwent CABG. Of these, 11.7% of patients were readmitted after 14 d but within 90 d of discharge with 5.1% of these patients having a diagnosis of new-onset depression. Postoperative new-onset depression was not associated with increased readmission morbidity, costs, or LOS. Mortality in new-onset depression readmissions was 1.2%, compared with 2.3% in all readmitted patients (P = 0.014). Depression was associated with lower odds of mortality (OR = 0.56, P = 0.02).

CONCLUSIONS

New-onset depression following CABG discharge was not associated with increased odds of mortality, morbidity, costs, or increased LOS on readmission. Rather, new-onset depression is associated with decreased odds of readmission mortality. Overall, CABG readmissions are decreasing, whereas the rate of new-onset depression is slightly increasing. Implementation of routine depression screening tools in postoperative CABG care may aid in early detection and management of depression to enhance postoperative recovery and quality of life.

National trends in volume-outcome relationships for extracorporeal membrane oxygenation

BACKGROUND

The use of extracorporeal membrane oxygenation (ECMO) has emerged as a common therapy for severe cardiopulmonary dysfunction. We aimed to describe the relationship of institutional volume with patient outcomes and examine transfer status to tertiary ECMO centers.

MATERIALS AND METHODS

Using the National Inpatient Sample, we identified adult patients who received ECMO from 2008 to 2014. Individual hospital volume was calculated as tertiles of total institutional discharges for each year independently.

RESULTS

Of the total 18,684 adult patients placed on ECMO, 2548 (13.6%), 5278 (28.2%), and 10,858 (58.1%) patients were admitted to low-, medium-, and high-volume centers, respectively. Unadjusted mortality at low-volume hospitals was less than that of medium- (43.7% versus 50.3%, P = 0.03) and high-volume hospitals (43.7% versus 55.6%, P < 0.001). Length of stay and cost were reduced at low-volume hospitals compared to both medium- and large-volume institutions (all P < 0.001). In high-volume institutions, transferred patients had greater postpropensity-matched mortality (58.5% versus 53.7%, P = 0.05) and cost ($190,299 versus $168,970, P = 0.009) compared to direct admissions. On exclusion of transferred patients from propensity analysis, mortality remained greater in high-volume compared to low-volume centers (50.2% versus 42.8%, P = 0.04). Predictors of mortality included treatment at high-volume centers, respiratory failure, and cardiogenic shock (all P < 0.001).

CONCLUSIONS

Our findings show increased in-hospital mortality in high-volume institutions and in patients transferred to tertiary centers. Whether this phenomenon represents selection bias or transfer from another facility deserves further investigation and will aid with the identification of surrogate markers for quality of high-risk interventions.

A nationwide study of treatment modalities for thoracic aortic injury

BACKGROUND

Thoracic aortic injuries have traditionally been associated with high morbidity and mortality. Thoracic endovascular aortic repair has emerged as a suitable alternative to open repair, but its impact at a national level remains ill defined. This study aimed to analyze the national trends of patient characteristics, outcomes, and resource utilization in the treatment of thoracic aortic injuries.

METHODS

Patients admitted with thoracic aortic injuries from 2005-2014 were identified in the National Inpatient Sample. Patients were identified as undergoing thoracic endovascular aortic repair, open surgery, or nonoperative management. The primary outcome was in-hospital mortality, while secondary outcomes included complications and costs. Multivariate regressions accounting for characteristics of the patients and injury characteristics were used to determine predictors of mortality and changes in cost.

RESULTS

Of the 11,257 patients admitted for thoracic aortic injuries, 33% received thoracic endovascular aortic repair, 8% open surgery, and 59% nonoperative management. Thoracic endovascular aortic repair had the great largest growth in case volume (P < .001). Compared to open surgery, thoracic endovascular aortic repair patients had greater rates of concomitant brain (17 vs 26%, P = .01), pulmonary (21 vs 33%, P < .001), and splenic injuries (2 vs 4%, P = .031). In-hospital mortality was greater for open surgery (odds ratio = 3.06, P = .003) and nonoperative management (odds ratio = 4.33, P < .001) than thoracic endovascular aortic repair. Over time, mortality rates for thoracic endovascular aortic repair decreased (P = .002), but increased for open surgery (P = .04). Interestingly, total costs with thoracic endovascular aortic repair increased (P = .004), while they decreased for open surgery (P = .031).

CONCLUSION

Our findings indicate the rapid adoption of thoracic endovascular aortic repair over open surgery for management of thoracic aortic injuries. Thoracic endovascular aortic repair is associated with lower mortality rates, but it has greater costs not otherwise explained by other patient factors.

Readmission and resource utilization after orthotopic heart transplant versus ventricular assist device in the National Readmissions Database, 2010-2014

BACKGROUND

As the technology of ventricular assist devices continues to improve, the morbidity and mortality for patients with a ventricular assist device is expected to approach that of orthotopic heart transplantation. The present study was performed to compare perioperative outcomes, readmission, and resource utilization between ventricular assist device implantation and orthotopic heart transplantation, using a national cohort.

METHODS

Patients who underwent either orthotopic heart transplantation or ventricular assist device implantation from 2010 to 2014 in the National Readmission Database were selected.

RESULTS

Of the 12,111 patients identified during the study period, 5,440 (45%) received orthotopic heart transplantation, while 6,671 (55%) received ventricular assist devices. Readmissions occurred frequently after ventricular assist device implantation and orthotopic heart transplantation, with greater rates at 30 days (29% versus 24%, P=.005) and 6 months (62% versus 46%, P < .001) for the ventricular assist device cohort. Cost of readmission was greater among ventricular assist device patients at 30 days ($29,115 versus $21,586, P=.0002) and 6 months ($34,878 versus $20,144, P = .0106).

CONCLUSION

Readmission rates and costs for patients with a ventricular assist device remain greater than their orthotopic heart transplantation counterparts. Given the projected increases in ventricular assist device utilization and limited transplant donor pool, further emphasis on cost containment and decreased readmissions for patients undergoing a ventricular assist device is essential to the viability of such therapy in the era of value-based health care delivery.

Search for Neutrinoless Double-β Decay in ^{76}Ge with the Majorana Demonstrator

The Majorana Collaboration is operating an array of high purity Ge detectors to search for neutrinoless double-β decay in ^{76}Ge. The Majorana Demonstrator comprises 44.1 kg of Ge detectors (29.7 kg enriched in ^{76}Ge) split between two modules contained in a low background shield at the Sanford Underground Research Facility in Lead, South Dakota. Here we present results from data taken during construction, commissioning, and the start of full operations. We achieve unprecedented energy resolution of 2.5 keV FWHM at Q_{ββ} and a very low background with no observed candidate events in 9.95 kg yr of enriched Ge exposure, resulting in a lower limit on the half-life of 1.9×10^{25}  yr (90% C.L.). This result constrains the effective Majorana neutrino mass to below 240-520 meV, depending on the matrix elements used. In our experimental configuration with the lowest background, the background is 4.0_{-2.5}^{+3.1}  counts/(FWHM t yr).

Correction: Phytoprostanes in almonds: identification, quantification, and impact of cultivar and type of cultivation

Correction for ‘Phytoprostanes in almonds: identification, quantification, and impact of cultivar and type of cultivation’ by A. M. Carrasco-Del Amor et al., RSC Adv., 2015, 5, 51233–51241.

Phytoprostanes in almonds: identification, quantification, and impact of cultivar and type of cultivation

The phytoprostane profile in 11 almonds cvs varied greatly according to the genotype and several factors (agricultural system conventional or ecological and irrigation).

Assessment of by-products from fresh-cut products for reuse as bioactive compounds

The fresh-cut industry is constantly growing and generating wastes. The major challenge for this industry consists in an environmentally sustainable production through re-utilization of by-products, for instance, in extraction of bioactive compounds. In this paper, the nutritional and functional compounds of apple, potato, cucumber, melon and watermelon by-products were investigated. The amount of by-product produced was of 10.10 to 30.80% of initial fresh weight depending on the product. By-products were characterized by low protein (<20 g/kg fresh weight) and fatty acid content (<5 g/kg fresh weight) and high levels of minerals. Carbohydrates content ranged from 43.7 to 235 g/kg fresh weight, while total dietary fibre was between 20 and 150 g/kg fresh weight The content of antioxidants (53.6 to 3453.2 mg/kg fresh weight) and total polyphenols (124.5 to 4250.2 mg/kg fresh weight) depended strongly on the type of by-product. In most cases, the nutritional and bioactive content was higher in the peel than in whole product. Apple peel was rich in carbohydrates, total dietary fibre, antioxidants and total polyphenols. Potato peel was high in iron. Melon was rich in magnesium. Watermelon peel was characterized by the level of potassium, and cucumber peel was rich in manganese, zinc, phosphorous, calcium and sodium. All these data demonstrate than natural by-product from fresh-cut industry could potentially be utilized as ingredients to design new functional foods with a future market.

[Nutrients and energy intake assessment in the critically ill patient on enteral nutritional therapy]

INTRODUCTION AND OBJECTIVES

The critically ill patient is especially susceptible to malnutrition due to his/her hypermetabolic state that leads to an increase in the nutritional requirementes, which many times are not compensated with the administered enteral formulas. The assessment of nutritional intake is essential in this kind of patients to know to what level their energetic and nutritional requirements are fulfilled, improving and monitoring in the most individualized possible way to indicated clinical and nutritional therapu.

METHODOLOGY

This is a retrospective study in which all patients admitted to the Intensive Care Unit of Virgen de las Nieves Hospital were studied from January to December of 2003, aged more than 18 years, and on enteral nutrition. A total of 90 patients (52 men and 38 women) were studied, 81% of which were older than 50 years, and 57% had hospital stays longer than 8 days, with a 21% mortality rate. Intake was assessed from time of admission and throughout the whole hospitalization period. Energetic requirements were calculated according to the modified Long's formula and micronutrients intakes were compared to existing general recommendations for the Spanish, European and American populations, and to vitaminic requirements in critically ill patients.

RESULTS

Percentages of mean energy and nutrients intakes in relation to theoretical calculated requirements for both genders are presented in figure 1. Mean energy intake was 1,326 cal in men and 917 cal in women. With regards to micronutrients intake, the values found for proteins, falts, and carbohydrates were lower than 50% of the requirements for both genders. The percentage of adequacy as referred to requirements for vitamins and minerals intake is shown in figure 2. Reference recommendations used correspond to sufficient intakes to cover the healthy individual requirements, therefore, the values obtained in our study show and adequacy greater than 75%, with the exception of particular elements such as vitamin A and magnesium. However, by taking a look at figure 3, which shows the adequacy of vitamins intake at recommended does for sick patients, the intake is lower than 25% of the requirements in all cases, and these deficiencies significantly interfere with wound healing, the immune, cardiovascular and nervous systems, as well as with metabolism of the remaining macronutrients leading to an unbalanced situation of the antioxidant system, worsening the patient's clinical status.

CONCLUSIONS

The present study confirms the need for monitoring individually the nutritional requirements in the critically ill patient and adapting recommendations to his/her metabolic changes, since currently these recommendations are not clearly defined for these situations. It is necessary to provide micronutrients doses closer to the patient's demands, so that the nutritional status and the balance of the antioxidant system may be preserved or improved, making the adopted clinical treatment more effective.

Microbial and sensory quality of commercial fresh processed red lettuce throughout the production chain and shelf life

Red pigmented 'Lollo Rosso' lettuce was processed under usual and controlled conditions in an industrial plant. At different steps of the production chain (reception, shredding, washing, draining, rinsing, centrifugation, and packaging), microbial counts were evaluated. Following industrial practices, processed lettuce was packaged at 5 degrees C in sealed polypropylene (PP) bags with an initial atmosphere containing 3 kPa O(2) and 5 kPa CO(2). The numbers of psychrotrophic bacteria, coliform and lactic acid bacteria (LAB) were influenced by all the studied steps of the production chain of the fresh processed 'Lollo Rosso' lettuce. Shredding, rinsing and centrifugation in particular increased bacterial counts. During a storage period of 7 days at 5 degrees C, sensory attributes (general appearance, texture, aroma, translucency, initial and persistent off-odors, leaves superficial browning, leaves edges browning, and decay) as well as microbial counts (psychrotrophic and mesophilic bacteria, coliforms and lactic acid bacteria) were monitored. Due to high microbial counts and off-odors evaluation, a shelf life shorter than 7 days should be considered for fresh processed 'Lollo Rosso' lettuce.

Mortality discrimination in acute myocardial infarction: comparison between APACHE III and SAPS II prognosis systems. PAEEC Group

OBJECTIVE

To compare the Acute Physiology, Age and Chronic Health Evaluation (APACHE) III with the Simplified Acute Physiology Score (SAPS II) in discriminating in-hospital mortality for intensive care unit (ICU) patients with acute myocardial infarction (AMI).

DESIGN

Prospective, observational, multicenter study.

SETTING

70 Spanish ICUs.

PATIENTS AND PARTICIPANTS

1711 patients with AMI and representative of Spanish ICUs.

MEASUREMENTS AND RESULTS

APACHE III score, APACHE III system probability of death (APACHE III probability), SAPS II score and in-hospital mortality were noted for each patient. Two hundred and twenty three (13.0 %) patients died in the hospital. The sensitivity (+/- SE), specificity (+/- SE), and accuracy (+/- SE) for the APACHE III score were, respectively, 75.8 +/- 2.9, 75.9 +/- 1.1, and 75.9 +/- 1.0. The corresponding figures for APACHE III probability were 75.3 +/- 2.9, 79.2 +/- 1.1, and 78.7 +/- 1.0, and for SAPS II 72.2 +/- 3.0, 75.9 +/- 1.1, and 75.4 +/- 1.0.

CONCLUSIONS

The results indicate good discrimination by the three tests. APACHE III probability shows a statistically significant improvement in accuracy and specificity when compared with the two scores.

Laminated Diatomaceous Sediments from the Guaymas Basin Slope (Central Gulf of California): 250,000-Year Climate Record

During Deep Sea Drilling Project-International Program of Ocean Drilling leg 64, December 1978 to January 1979, the initial test of the Deep Sea Drilling Project's hydraulic piston corer obtained an almost undisturbed section from a 152-meter hole into the sediments of the oxygen minimum zone at a depth of 655 meters along the Guaymas slope in the central Gulf of California. The section records variations in climate, productivity, and circulation for more than 250,000 years of Late Pleistocene to Holocene history with recordings of seasonal variations in these parameters in the laminated sections.