Qualitative Analysis of the Host-Perceived Impact of Unidirectional Global Surgery Training in Kijabe, Kenya: Benefits, Challenges, and a Desire for Bidirectional Exchange

Background

As globalization of surgical training increases, growing evidence demonstrates a positive impact of global surgery experiences on trainees from high-income countries (HIC). However, few studies have assessed the impact of these largely unidirectional experiences from the perspectives of host surgical personnel from low- and middle-income countries (LMIC). This study aimed to assess the impact of unidirectional visitor involvement from the perspectives of host surgical personnel in Kijabe, Kenya.

Methods

Voluntary semi-structured interviews were conducted with 43 host surgical personnel at a tertiary referral hospital in Kijabe, Kenya. Qualitative analysis was used to identify salient and recurring themes related to host experiences with visiting surgical personnel. Perceived benefits and challenges of HIC involvement and host interest in bidirectional exchange were assessed.

Results

Benefits of visitor involvement included positive learning experiences (95.3%), capacity building (83.7%), exposure to diverse practices and perspectives (74.4%), improved work ethic (51.2%), shared workload (44.2%), access to resources (41.9%), visitor contributions to patient care (41.9%), and mentorship opportunities (37.2%). Challenges included short stays (86.0%), visitor adaptation and integration (83.7%), cultural differences (67.4%), visitors with problematic behaviors (53.5%), learner saturation (34.9%), language barriers (32.6%), and perceived power imbalances between HIC and LMIC personnel (27.9%). Nearly half of host participants expressed concerns about the lack of balanced exchange between HIC and LMIC programs (48.8%). Almost all (96.9%) host trainees expressed interest in a bidirectional exchange program.

Conclusion

As the field of global surgery continues to evolve, further assessment and representation of host perspectives is necessary to identify and address challenges and promote equitable, mutually beneficial partnerships between surgical programs in HIC and LMIC.

Design of a Novel Online, Modular, Flipped-classroom Surgical Curriculum for East, Central, and Southern Africa

Objective

We describe a structured approach to developing a standardized curriculum for surgical trainees in East, Central, and Southern Africa (ECSA).

Summary Background Data

Surgical education is essential to closing the surgical access gap in ECSA. Given its importance for surgical education, the development of a standardized curriculum was deemed necessary.

Methods

We utilized Kern's 6-step approach to curriculum development to design an online, modular, flipped-classroom surgical curriculum. Steps included global and targeted needs assessments, determination of goals and objectives, the establishment of educational strategies, implementation, and evaluation.

Results

Global needs assessment identified the development of a standardized curriculum as an essential next step in the growth of surgical education programs in ECSA. Targeted needs assessment of stakeholders found medical knowledge challenges, regulatory requirements, language variance, content gaps, expense and availability of resources, faculty numbers, and content delivery method to be factors to inform curriculum design. Goals emerged to increase uniformity and consistency in training, create contextually relevant material, incorporate best educational practices, reduce faculty burden, and ease content delivery and updates. Educational strategies centered on developing an online, flipped-classroom, modular curriculum emphasizing textual simplicity, multimedia components, and incorporation of active learning strategies. The implementation process involved establishing thematic topics and subtopics, the content of which was authored by regional surgeon educators and edited by content experts. Evaluation was performed by recording participation, soliciting user feedback, and evaluating scores on a certification examination.

Conclusions

We present the systematic design of a large-scale, context-relevant, data-driven surgical curriculum for the ECSA region.

Does Intentional Support of Degree Programs in General Surgery Residency Affect Research Productivity or Pursuit of Academic Surgery? A Multi-Institutional Study

OBJECTIVE

To determine whether pursuit of an advanced degree during dedicated research time (DRT) in a general surgery residency training program impacts a resident's research productivity.

DESIGN

A retrospective, multi-institutional cohort study.

SETTING

General surgery residency programs that were approved to graduate more than 5 categorical residents per year and that offered at least 1 year of DRT were contacted for participation in the study. A total of 10 general surgery residency programs agreed to participate in the study.

PARTICIPANTS

Residents who started their residency between 2000 and 2012 and spent at least one full year in DRT (n = 511) were included. Those who completed an advanced degree were compared on the following parameters to those who did not complete one: total number of papers, first-author papers, the Journal Citation Reports impact factors of publication (2018, or most recent), and first position after residency or fellowship training.

RESULTS

During DRT, 87 (17%) residents obtained an advanced degree. The most common degree obtained was a Master of Public Health (MPH, n = 42 (48.8%)). Residents who did not obtain an advanced degree during DRT published fewer papers (median 8, [interquartile range 4-12]) than those who obtained a degree (9, [6-17]) (p = 0.002). They also published fewer first author papers (3, [2-6]) vs (5, [2-9]) (p = 0.002) than those who obtained a degree. Resident impact factor (RIF) was calculated using Journal Citation Reports impact factor and author position. Those who did not earn an advanced degree had a lower RIF (adjusted RIF, 84 ± 4 vs 134 ± 5, p < 0.001) compared to those who did. There was no association between obtaining a degree and pursuit of academic surgery (p = 0.13) CONCLUSIONS: Pursuit of an advanced degree during DRT is associated with increased research productivity but is not associated with pursuit of an academic career.

MDM2 antagonists overcome intrinsic resistance to CDK4/6 inhibition by inducing p21

Intrinsic resistance of unknown mechanism impedes the clinical utility of inhibitors of cyclin-dependent kinases 4 and 6 (CDK4/6i) in malignancies other than breast cancer. Here, we used melanoma patient-derived xenografts (PDXs) to study the mechanisms for CDK4/6i resistance in preclinical settings. We observed that melanoma PDXs resistant to CDK4/6i frequently displayed activation of the phosphatidylinositol 3-kinase (PI3K)-AKT pathway, and inhibition of this pathway improved CDK4/6i response in a p21-dependent manner. We showed that a target of p21, CDK2, was necessary for proliferation in CDK4/6i-treated cells. Upon treatment with CDK4/6i, melanoma cells up-regulated cyclin D1, which sequestered p21 and another CDK inhibitor, p27, leaving a shortage of p21 and p27 available to bind and inhibit CDK2. Therefore, we tested whether induction of p21 in resistant melanoma cells would render them responsive to CDK4/6i. Because p21 is transcriptionally driven by p53, we coadministered CDK4/6i with a murine double minute (MDM2) antagonist to stabilize p53, allowing p21 accumulation. This resulted in improved antitumor activity in PDXs and in murine melanoma. Furthermore, coadministration of CDK4/6 and MDM2 antagonists with standard of care therapy caused tumor regression. Notably, the molecular features associated with response to CDK4/6 and MDM2 inhibitors in PDXs were recapitulated by an ex vivo organotypic slice culture assay, which could potentially be adopted in the clinic for patient stratification. Our findings provide a rationale for cotargeting CDK4/6 and MDM2 in melanoma.

Metastatic Melanoma Patient-Derived Xenografts Respond to MDM2 Inhibition as a Single Agent or in Combination with BRAF/MEK Inhibition

PURPOSE

Over 60% of patients with melanoma respond to immune checkpoint inhibitor (ICI) therapy, but many subsequently progress on these therapies. Second-line targeted therapy is based on BRAF mutation status, but no available agents are available for NRAS, NF1, CDKN2A, PTEN, and TP53 mutations. Over 70% of melanoma tumors have activation of the MAPK pathway due to BRAF or NRAS mutations, while loss or mutation of CDKN2A occurs in approximately 40% of melanomas, resulting in unregulated MDM2-mediated ubiquitination and degradation of p53. Here, we investigated the therapeutic efficacy of over-riding MDM2-mediated degradation of p53 in melanoma with an MDM2 inhibitor that interrupts MDM2 ubiquitination of p53, treating tumor-bearing mice with the MDM2 inhibitor alone or combined with MAPK-targeted therapy.

EXPERIMENTAL DESIGN

To characterize the ability of the MDM2 antagonist, KRT-232, to inhibit tumor growth, we established patient-derived xenografts (PDX) from 15 patients with melanoma. Mice were treated with KRT-232 or a combination with BRAF and/or MEK inhibitors. Tumor growth, gene mutation status, as well as protein and protein-phosphoprotein changes, were analyzed.

RESULTS

One-hundred percent of the 15 PDX tumors exhibited significant growth inhibition either in response to KRT-232 alone or in combination with BRAF and/or MEK inhibitors. Only BRAFV600WT tumors responded to KRT-232 treatment alone while BRAFV600E/M PDXs exhibited a synergistic response to the combination of KRT-232 and BRAF/MEK inhibitors.

CONCLUSIONS

KRT-232 is an effective therapy for the treatment of either BRAFWT or PAN WT (BRAFWT, NRASWT) TP53WT melanomas. In combination with BRAF and/or MEK inhibitors, KRT-232 may be an effective treatment strategy for BRAFV600-mutant tumors.

Global Surgery Electives: A Strategy to Improve Care to Domestic Underserved Populations?

BACKGROUND

In the United States, a shortage of general surgeons exists, primarily in rural, poor, and minority communities. Identification of strategies that increase resident interest in underserved regions provides valuable information in understanding and addressing this shortage. In particular, surgical experience abroad exposes residents to practice in low-resource and rural settings. As residency programs increasingly offer global surgery electives, we explore whether the presence of an international surgical rotation affects graduates' future practice patterns in underserved communities domestically.

METHODS

We surveyed general surgery residency graduates at a single academic institution. Those who finished general surgery residency from 2001 to 2018 were included. Participant demographics, current practice demographics, and perceptions related to global surgery and underserved populations were collected. Respondents were stratified based on whether they did ("after") or did not ("before") have the opportunity to participate in the Kijabe rotation (started in 2011), defined by graduation year.

RESULTS

Out of 119 eligible program graduates, 64 (53.7%) completed the survey, and 33 (51.6%) of the respondents graduated following the implementation of the Kijabe rotation. Two participants defined their primary current practice location as international. Fifteen (45.5%) in the "After" group indicated an interest in working with underserved populations following residency, compared to 5 (17.8%) of the "Before" group (P = 0.074). Furthermore, 20 (60.6%) respondents in the "After" group expressed interest in working with underserved populations even if it meant making less money. In the "Before" group, only 13 (46.4%) responded similarly (P = 0.268). Eleven (9.2%) residents rotated at Kijabe. Those who participated in the Kijabe rotation reported an uninsured rate of 36.7% for their current patient population, compared to rate of 13.9% in those who did not rotate there (P = 0.22).

CONCLUSIONS

At a single institution, our results suggest that participation in an international surgical rotation in a resource-constrained setting may be associated with increased care for underserved populations in future clinical practice. These results could be due to self-selection of residents who prioritize global surgery as part of their residency experience, or due to increased exposure to underserved patients through global surgery.

Early Melanoma Nodal Positivity and Biopsy Rates Before and After Implementation of the 7th Edition of the AJCC Cancer Staging Manual

Importance

There has been a continued increase in the incidence of newly diagnosed melanomas, most of which are T1 melanomas. The associations between changes in tumor staging, implemented with the 7th edition of the AJCC Cancer Staging Manual (AJCC 7), and sentinel lymph node biopsy rates and nodal positivity rates remain to be seen.

Objective

To evaluate the change that the implementation of the AJCC 7 had on staging criteria and the distribution of thin melanomas requiring nodal surgery and nodal positivity rates.

Design, Setting, and Participants

Retrospective cross-sectional study from 2004 through 2013 of all adults (≥18 years) diagnosed with a T1 (Breslow depth ≤1.0 mm) melanoma using The National Cancer Database that captures 70% of all newly diagnosed cancers from accredited Commission on Cancer organizations, including both academic and community settings. Data were analyzed in May 2017.

Exposures

Patients were grouped together based on year of diagnosis, before and after 2009.

Main Outcomes and Measures

To determine the sentinel lymph node biopsy rate before and after the implementation of the AJCC 7.

Results

A total of 141 280 patients met inclusion criteria. Of 86 846 patients diagnosed from 2004 through 2009, 53.7% (49 644) were male and had a mean (SD) age of 57.7 (16.4) years. Of 54 434 patients diagnosed from 2010 through 2013, 54.3% (31 086) were male and had a mean (SD) age of 59.5 (15.9) years. After 2010, there was a 3.8% decrease in the number of nodal surgeries performed (32 485 of 86 846 patients [37.6%] vs 18 379 of 54 434 patients [33.8%]; P < .001). The nodal positivity rate decreased 1.0% from (9.8% [3166 of 86 846] to 8.8% [1618 of 54 434]) (P < .001). An increase in the proportion of T1b melanomas being evaluated, from 48.8% to 62.2%, was seen (P < .001). Of T1b melanomas that underwent nodal evaluation from 2004 through 2009, 74.0% had Clark level IV (invasion of the reticular dermis) or Clark level V (invasion of the deep, subcutaneous tissue) and 9.5% were ulcerated. From 2010 through 2013, of the T1b melanomas undergoing nodal evaluation, 82.6% had an elevated mitotic rate only, 3.7% were ulcerated, and 13.7% had both ulceration and an elevated mitotic rate.

Conclusions and Relevance

It appears that after the institution of AJCC 7, there was an overall decrease in the number of T1 melanomas undergoing nodal biopsy without a clinically relevant change in sentinel lymph node positivity, with an increase in the number of T1b melanomas undergoing nodal evaluation.

Resection for anal melanoma: Is there an optimal approach?

BACKGROUND

Anal melanoma is a lethal disease, but its rarity makes understanding the behavior and effects of intervention challenging. Local resection and abdominal perineal resection are the proposed treatments for nonmetastatic disease. We hypothesize that there is no difference in overall survival between surgical therapies.

METHODS

The National Cancer Database (2004-2014) was queried for adults with a diagnosis of anal melanoma who underwent curative resection. Patients with metastatic disease were excluded. Patients were divided into 2 groups based on surgical approach (local resection versus abdominal perineal resection). Unadjusted and adjusted analyses were used to examine the association between surgical approach and R0 resection rate, short-term survival, and overall survival.

RESULTS

A total of 570 patients with anal melanoma who underwent resection were identified. The median age was 68 and 59% of patients were female. A total of 383 (67%) underwent local resection. Abdominal perineal resection was associated with higher rates of R0 resection rates (abdominal perineal resection 91% versus local resection 73%; P < .001). Overall 5-year survival for the entire cohort was 20%. There was no significant difference in 5-year overall survival (abdominal perineal resection 21% vs local resection 17%; P = .31). This persisted in a Cox proportional hazard multivariable model (odds ratio 0.84; 95% confidence interval 0.66-1.06; P = .15). Additionally, there was no improvement in overall survival for patients who underwent R0 resection (odds ratio 1.18; 95% confidence interval 0.90-1.56; P = .22).

CONCLUSION

Anal melanoma has a very poor prognosis, with only 1 of 5 patients alive at 5 years. Although local resection was associated with lower rates of R0 resection, there was no discernable difference in overall survival in both unadjusted and adjusted analysis.

Age greater than 60 years portends a worse prognosis in patients with papillary thyroid cancer: should there be three age categories for staging?

Background

Age is an important prognostic factor in papillary thyroid cancer (PTC), with better survival observed in patients < 45 years of age, regardless of stage. Although the impact of increasing age on PTC-related survival is well-known, previous studies have focused on survival relative to age 45 years only. As the number of patients entering their 7th decade of life increases, PTC-related survival in this demographic becomes increasingly important. Survival in patients ≥ 60 years specifically compared to other groups has not previously been examined. We sought to determine whether age ≥ 60 years is an adverse prognostic factor for disease-specific survival and recurrence in patients with PTC.

Methods

The California Cancer Registry database was linked to inpatient and ambulatory patient records from the Office of Statewide Health Planning and Development for the years 2000–2011. This linked database was queried for patients diagnosed with papillary thyroid cancer and treated with surgery. We then identified prognostic factors related to both 5-year and 10-year disease-specific survival and disease-free survival in patients ≤ 45, 45–59, and ≥ 60 years. Multivariable Cox proportional hazard models were created to test the effect of age ≥ 60 on disease-specific and disease-free survival, controlling for clinical, treatment, and demographic factors.

Results

The final cohort included 15,675 patients. Of the group, 46.3% were between 18 and 44 years of age, 33.6% were 45–59 years, and 20.1% were ≥ 60. Univariate analysis showed that compared to other groups, patients ≥ 60 were more likely to be male (p < 0.001), present with tumors > 5 cm (p < 0.001), more likely to have metastatic disease (p < 0.001), less likely to receive radioactive iodine (p < 0.001), and more likely to receive external beam radiation therapy (p < 0.001). In multivariable Cox proportional hazards models for 5 and 10-year disease-free survival, age ≥ 60 was associated with higher risk of disease at 5 and 10-years (HR 2.3 and 1.9 respectively, p < 0.001). Similar results were observed for 5 and 10-year disease-specific survival (HR 38.0 and 30.0 respectively, p < 0.001) after controlling for gender, race, co-morbidity, stage, surgical procedure, radioactive iodine, insurance, and hospital volume.

Conclusions

Patients ≥ 60 years of age have worse DSS and DFS after a diagnosis of PTC, across all stages of disease. Given that patients over the age of 45 years have progressively worse survival as they age, these data support having three age groups, 18–44 years of age, 45–59 years, and ≥ 60 as an independent predictor of survival and recurrence to current staging guidelines.

Predictors of Antiestrogen Recommendation in Women With Estrogen Receptor-Positive Ductal Carcinoma In Situ

BACKGROUND

Antiestrogen (anti-e) use in estrogen receptor-positive (ER+) ductal carcinoma in situ (DCIS) has been shown to reduce the incidence of noninvasive and invasive breast cancer. Few studies have evaluated factors associated with anti-e recommendation in ER+ DCIS.

METHODS

The California Cancer Registry was queried for female patients diagnosed with ER+ DCIS and treated with lumpectomy or unilateral mastectomy from 2004 to 2011. Patient demographics, comorbidities, and clinical characteristics were analyzed for association with anti-e recommendation.

RESULTS

Of 5,527 patients identified, 76.4% patients underwent lumpectomy and 23.6% underwent unilateral mastectomy. Of the total cohort, 31.6% patients were recommended anti-e therapy, 60.4% were not, and the remaining 8.0% were recommended anti-e, but administration was not documented. Performance of lumpectomy predicted anti-e use compared with mastectomy (odds ratio [OR], 2.08; 95% CI, 1.77-2.43). Asian/Pacific Islanders were more often recommended anti-e therapy when compared with whites (OR, 1.28; 95% CI, 1.10-1.49). Patients younger than 70 years were more often recommended anti-e (age, 18-49 years: OR, 1.38; CI, 1.12-1.71; and age, 50-69 years: OR, 1.43; CI, 1.20-1.71).

CONCLUSIONS

Despite current guidelines to consider the use of anti-e therapy, recommendation of anti-e after surgical treatment of DCIS is low, having been recommended to 40% of patients, and used by fewer than one-third. Significant predictors include lumpectomy compared with unilateral mastectomy, Asian/Pacific Islander race, younger age, and number of comorbidities. Further work is merited to understand patterns of anti-e therapy recommendation by providers in patients with DCIS.

Ipilimumab-induced Guillain-Barré Syndrome Presenting as Dysautonomia: An Unusual Presentation of a Rare Complication of Immunotherapy

Immune-related adverse events are common and well-documented in patients treated with ipilimumab, a cytotoxic T-lymphocyte antigen-4 monoclonal antibody approved for the treatment of metastatic and stage III melanoma. Neurological complications are rare, but widely variable and potentially devastating. Here, we discuss a case of a patient who was treated with a single dose of ipilimumab for resected stage III melanoma. She subsequently developed pandysautonomia that manifested as a tonically dilated pupil, gastrointestinal dysmotility, urinary retention, and profound orthostatic hypotension. Guillain-Barré syndrome was diagnosed on electromyography. She was treated with intravenous immunoglobulin, droxidopa, and supportive care, with prolonged but eventual recovery. Given the broadening use of ipilimumab in the treatment of advanced and metastatic melanoma, awareness and recognition of its profound immune-mediated adverse effects are essential.

Bilateral Changes in Deep Tissue Environment After Manual Lymphatic Drainage in Patients with Breast Cancer Treatment-Related Lymphedema

BACKGROUND

Breast cancer treatment-related lymphedema (BCRL) arises from a mechanical insufficiency following cancer therapies. Early BCRL detection and personalized intervention require an improved understanding of the physiological processes that initiate lymphatic impairment. Here, internal magnetic resonance imaging (MRI) measures of the tissue microenvironment were paired with clinical measures of tissue structure to test fundamental hypotheses regarding structural tissue and muscle changes after the commonly used therapeutic intervention of manual lymphatic drainage (MLD).

METHODS AND RESULTS

Measurements to identify lymphatic dysfunction in healthy volunteers (n = 29) and patients with BCRL (n = 16) consisted of (1) limb volume, tissue dielectric constant, and bioelectrical impedance (i.e., non-MRI measures); (2) qualitative 3 Tesla diffusion-weighted, T₁-weighted and T₂-weighted MRI; and (3) quantitative multi-echo T₂ MRI of the axilla. Measurements were repeated in patients immediately following MLD. Normative control and BCRL T₂ values were quantified and a signed Wilcoxon Rank-Sum test was applied (significance: two-sided p < 0.05). Non-MRI measures yielded significant capacity for discriminating between arms with versus without clinical signs of BCRL, yet yielded no change in response to MLD. Alternatively, a significant increase in deep tissue T₂ on the involved (pre T₂ = 0.0371 ± 0.003 seconds; post T₂ = 0.0389 ± 0.003; p = 0.029) and contralateral (pre T₂ = 0.0365 ± 0.002; post T₂ = 0.0395 ± 0.002; p < 0.01) arms was observed. Trends for larger T₂ increases on the involved side after MLD in patients with stage 2 BCRL relative to earlier stages 0 and 1 BCRL were observed, consistent with tissue composition changes in later stages of BCRL manifesting as breakdown of fibrotic tissue after MLD in the involved arm. Contrast consistent with relocation of fluid to the contralateral quadrant was observed in all stages.

CONCLUSION

Quantitative deep tissue T₂ MRI values yielded significant changes following MLD treatment, whereas non-MRI measurements did not vary. These findings highlight that internal imaging measures of tissue composition may be useful for evaluating how current and emerging therapies impact tissue function.

Single cell analysis of human tissues and solid tumors with mass cytometry

BACKGROUND

Mass cytometry measures 36 or more markers per cell and is an appealing platform for comprehensive phenotyping of cells in human tissue and tumor biopsies. While tissue disaggregation and fluorescence cytometry protocols were pioneered decades ago, it is not known whether established protocols will be effective for mass cytometry and maintain cancer and stromal cell diversity.

METHODS

Tissue preparation techniques were systematically compared for gliomas and melanomas, patient derived xenografts of small cell lung cancer, and tonsil tissue as a control. Enzymes assessed included DNase, HyQTase, TrypLE, collagenase (Col) II, Col IV, Col V, and Col XI. Fluorescence and mass cytometry were used to track cell subset abundance following different enzyme combinations and treatment times.

RESULTS

Mechanical disaggregation paired with enzymatic dissociation by Col II, Col IV, Col V, or Col XI plus DNase for 1 h produced the highest yield of viable cells per gram of tissue. Longer dissociation times led to increasing cell death and disproportionate loss of cell subsets. Key markers for establishing cell identity included CD45, CD3, CD4, CD8, CD19, CD64, HLA-DR, CD11c, CD56, CD44, GFAP, S100B, SOX2, nestin, vimentin, cytokeratin, and CD31. Mass and fluorescence cytometry identified comparable frequencies of cancer cell subsets, leukocytes, and endothelial cells in glioma (R = 0.97), and tonsil (R = 0.98).

CONCLUSIONS

This investigation establishes standard procedures for preparing viable single cell suspensions that preserve the cellular diversity of human tissue microenvironments. © 2016 International Clinical Cytometry Society.

Hypocaloric enteral nutrition protects against hypoglycemia associated with intensive insulin therapy better than intravenous dextrose

Intensive insulin therapy treats hyperglycemia but increases the risk of hypoglycemia. Typically, intravenous dextrose is given to prevent hypoglycemia; however, enteral nutrition is preferred. We hypothesized that the provision of hypocaloric enteral nutrition would protect against hypoglycemia. A retrospective analysis was performed evaluating patients treated with intensive insulin therapy comparing the use of enteral nutrition versus a dextrose-only intravenous solution. Nutrition in the 2 hours before each blood glucose test was assessed, and the association with hypoglycemia (50 mg/dL or less) evaluated. Risk of hypoglycemia as a function of nutrition type and rate was estimated by multivariable regression. A total of 26,140 blood glucose tests were collected on 1289 patients. Hypoglycemia occurred in 6.4 per cent of patients. In regression models, enteral nutrition was the strongest protective factor against hypoglycemia (P < 0.001) with the largest risk reduction (steepest portion of the curve) occurring at 60 per cent goal. Hypocaloric enteral nutrition showed a greater risk reduction than a peripheral dextrose-only intravenous solution alone. In the setting of intensive insulin therapy, the provision of enteral nutrition, even if hypocaloric, is sufficient to protect against hypoglycemia. Future prospective studies should evaluate the efficacy of enteral nutrition in reducing the risk of hypoglycemia and whether lower rates of hypoglycemia correspond to improved outcomes.

Hypocaloric Enteral Nutrition Protects against Hypoglycemia Associated with Intensive Insulin Therapy Better than Intravenous Dextrose

Intensive insulin therapy treats hyperglycemia but increases the risk of hypoglycemia. Typically, intravenous dextrose is given to prevent hypoglycemia; however, enteral nutrition is preferred. We hypothesized that the provision of hypocaloric enteral nutrition would protect against hypoglycemia. A retrospective analysis was performed evaluating patients treated with intensive insulin therapy comparing the use of enteral nutrition versus a dextrose-only intravenous solution. Nutrition in the 2 hours before each blood glucose test was assessed, and the association with hypoglycemia (50 mg/dL or less) evaluated. Risk of hypoglycemia as a function of nutrition type and rate was estimated by multivariable regression. A total of 26,140 blood glucose tests were collected on 1289 patients. Hypoglycemia occurred in 6.4 per cent of patients. In regression models, enteral nutrition was the strongest protective factor against hypoglycemia ( P < 0.001) with the largest risk reduction (steepest portion of the curve) occurring at 60 per cent goal. Hypocaloric enteral nutrition showed a greater risk reduction than a peripheral dextrose-only intravenous solution alone. In the setting of intensive insulin therapy, the provision of enteral nutrition, even if hypocaloric, is sufficient to protect against hypoglycemia. Future prospective studies should evaluate the efficacy of enteral nutrition in reducing the risk of hypoglycemia and whether lower rates of hypoglycemia correspond to improved outcomes.

Survival analysis of contralateral prophylactic mastectomy: a question of selection bias

BACKGROUND

Rates of contralateral prophylactic mastectomy (CPM) in women with breast cancer have increased, but most studies fail to show a survival benefit. We evaluated survival among CPM patients compared to patients undergoing single mastectomy (SM).

METHODS

The Surveillance, Epidemiology, and End Results database was used to identify unilateral breast cancer patients who underwent mastectomy with/without CPM from 1998 to 2010. Case-control analysis was performed with CPM cases matched to SM controls on the basis of age group, race/ethnicity, extent of surgery, grade, T classification, N classification, estrogen receptor status, and propensity score. Survival analyses included Kaplan-Meier curves and univariate and multivariate proportional hazard models to determine factors associated with disease-specific (DSS) and overall survival (OS).

RESULTS

A total of 26,526 CPM patients were identified. On multivariate regression analysis, increasing age, greater extent of surgery, increasing T and N stage, African American race, Hispanic ethnicity, poorly differentiated grade, and estrogen receptor negativity were associated with increased risk of death. CPM was associated with improved DSS (HR 0.86, 95 % CI 0.79-0.93) and even greater OS (HR 0.76, 95 % CI 0.71-0.81) compared with SM. Contralateral breast cancer (CBC) occurred in 1.6 % of women in the cohort. Removing CBC cases from analysis had little impact on CPM DSS (HR 0.86, 95 % CI 0.79-0.93) and OS (0.77, 95 % CI 0.72-0.82) suggesting that prevention of CBC by CPM does not explain the observed survival benefit.

CONCLUSIONS

CPM rates continue to rise. The improved DSS and OS observed with CPM support selection bias. Prospective trials are needed to determine cohorts of patients most likely to benefit from CPM.

Relationship of hyperglycemia and surgical-site infection in orthopaedic surgery

BACKGROUND

The impact of perioperative hyperglycemia in orthopaedic surgery is not well defined. We hypothesized that hyperglycemia is an independent risk factor for thirty-day surgical-site infection in orthopaedic trauma patients without a history of diabetes at hospital admission.

METHODS

Patients eighteen years of age or older with isolated orthopaedic injuries requiring acute operative intervention were studied. Patients with diabetes, injuries to other body systems, a history of corticosteroid use, or admission to the intensive care unit were excluded. Blood glucose values were obtained, and hyperglycemia was defined in two ways. First, patients with two or more blood glucose levels of ≥200 mg/dL were identified. Second, the hyperglycemic index, a validated measure of overall glucose control during hospitalization, was calculated for each patient. A hyperglycemic index of ≥1.76 (equivalent to ≥140 mg/dL) was considered to indicate hyperglycemia. The primary outcome was thirty-day surgical-site infection. Multivariable logistic regression models evaluating the effect of the markers of hyperglycemia, after controlling for open fractures, were constructed.

RESULTS

Seven hundred and ninety patients were identified. There were 268 open fractures (33.9%). Twenty-one thirty-day surgical-site infections (2.7%) were recorded. Age, race, comorbidities, injury severity, and blood transfusion were not associated with the primary outcome. Of the 790 patients, 294 (37.2%) had more than one glucose value of ≥200 mg/dL. This factor was associated with thirty-day surgical-site infection, with thirteen (4.4%) of the 294 patients with that indication of hyperglycemia having a surgical-site infection versus eight (1.6%) of the 496 patients without more than one glucose value of ≥200 mg/dL (p = 0.02). One hundred and thirty-four (17.0%) of the 790 patients had a hyperglycemic index of ≥1.76, and this was also associated was thirty-day surgical-site infection (ten [7.5%] of 134 versus eleven [1.7%] of 656; p < 0.001). Multivariable logistic regression models demonstrated that two or more blood glucose levels of ≥200 mg/dL was a risk factor for thirty-day surgical-site infection (odds ratio [OR]: 2.7, 95% confidence interval [CI]: 1.1 to 6.7) after adjustment for open fractures (OR: 3.2, 95% CI: 1.3 to 7.8). A second model demonstrated that a hyperglycemic index of ≥1.76 was an independent risk factor for surgical-site infection (OR: 4.9, 95% CI: 2.0 to 11.8) after controlling for open fractures (OR: 3.3, 95% CI: 1.4 to 8.3).

CONCLUSIONS

Hyperglycemia was an independent risk factor for thirty-day surgical-site infection in orthopaedic trauma patients without a history of diabetes.

The place for glycemic control in the surgical patient

BACKGROUND

Hyperglycemia is common in surgical patients and is associated with adverse outcomes. Conflicting data exist regarding the best method and the value of glycemic control in various patient populations. The contributions to hyperglycemia and the components of its control are complex and overlapping and likely contribute to the documented variation in outcomes. We provide an overview of the physiologic contributors to hyperglycemia and its control, review the differences in the major randomized trial results, and summarize the data regarding glycemic control in surgical patients.

METHODS

Major reviews of the pathophysiology of hyperglycemia in surgical patients, large randomized trials in critically ill and peri-operative populations, and meta-analyses were reviewed. Summations are provided for the critically ill population and for the peri-operative group.

RESULTS

A substantial physiologic rationale exists for the control of hyperglycemia in surgical patients during critical illness and in the peri-operative period. Randomized, controlled studies are limited predominately to critically ill populations. The data support controlling hyperglycemia to a serum glucose concentration <200 mg/dL, but the absolute target range remains controversial and studied inadequately. The data indicate the benefit of tight glycemic control using insulin to achieve a target of 80-110 mg/dL (intensive insulin therapy [IIT]) vs. a liberal target of 180-200 mg/dL in critically ill surgical patients, although hypoglycemia is more common with IIT. Inadequate studies are available in the peri-operative period to draw conclusions about non-critically ill surgical patients, but the weight of the data suggests control to < 200 mg/dL likely is beneficial.

CONCLUSIONS

Surgical patients benefit from maintaining serum glucose concentrations <200 mg/dL. Intensive insulin therapy (80-110 mg/dL), which appears beneficial in critically ill surgical patients but requires frequent measurement of glucose to avoid hypoglycemia. Further studies are needed to determine the appropriate target range and the influence of nutritional provision and other factors on outcome.

Provision of balanced nutrition protects against hypoglycemia in the critically ill surgical patient

BACKGROUND

Intensive insulin therapy lowers blood glucose and improves outcomes but increases the risk of hypoglycemia. Typically, insulin protocols require a dextrose solution to prevent hypoglycemia. The authors hypothesized that the provision of balanced nutrition (enteral nutrition [EN] or parenteral nutrition [PN]) would be more protective against hypoglycemia (≤50 mg/dL) than carbohydrate alone.

METHODS

A retrospective analysis was performed of patients treated with intensive insulin therapy and surviving ≥24 hours. The computer-based insulin protocol requires infusion of D10W at 30 mL/h if EN or PN is not provided. Nutrition provision was assessed in 2-hour increments, comparing periods of blood glucose control with and without balanced nutrition. The risk of hypoglycemia for each blood glucose measurement was estimated by multivariable regression.

RESULTS

In total, 66,592 glucose measurements were collected on 1392 patients. Hypoglycemic events occurred in 5.8/1000 glucose tests after 2 hours without balanced nutrition compared to 2.2/1000 tests when balanced nutrition was given in the preceding 2 hours. In multivariable regression models, balanced nutrition was the strongest protective factor against hypoglycemia. Patients who did not receive balanced nutrition in the preceding 2 hours had a 3 times increase in the odds of a hypoglycemic event at their next glucose check (odds ratio = 3.6, P < .001). Providing carbohydrate alone was not protective.

CONCLUSIONS

Balanced nutrition is associated with reduced risk of hypoglycemia. These results suggest that balanced nutrition should be given when insulin therapy is initiated. Future studies should evaluate the efficacy of EN vs PN in preventing hypoglycemia.

The use of a multidisciplinary morbidity and mortality conference to incorporate ACGME general competencies

BACKGROUND

The Surgical Morbidity and Mortality conference has long been used as an opportunity for both process improvement and resident education. With recent heightened focus on creating environments of safety and on meeting the Accreditation Council for Graduate Medical Education (ACGME) General Competencies, novel approaches are required. With the understanding that the provision of medical care is an inherently multidisciplinary enterprise, we advocate the creation and use of a Multidisciplinary Morbidity and Mortality conference (MM&M) as a means to establish this culture of safety while teaching the ACGME General Competencies to surgery residents.

METHODS

A quarterly MM&M conference was implemented to foster communication between disciplines, provide a forum for quality improvement, and enhance patient care. All stakeholders in the perioperative enterprise attend, including the departments of surgery, anesthesia, radiology, pharmacy, nursing, environmental services, risk management, and patient services. Cases that expose system issues with potential to harm patients are discussed in an open, nonconfrontational forum. Solutions are presented and initiatives developed to improve patient outcomes. We retrospectively reviewed the topics presented since the conference's inception, grouping them into 1 of 7 categories. We then evaluated the completion of the improvement initiatives developed after discussion at the conference.

RESULTS

Over a 21-month period, 11 cases were discussed with 23 "actionable" initiatives for quality improvement. Cases were grouped by category; procedures (36.5%), process (36.5%), patient-related (9%), communication (9%), medication (9%), device (0%), and ethics (0%). All cases discussed addressed at least 4 of the 6 ACGME General Competencies.

CONCLUSIONS

Like the practice of medicine, the occurrence of adverse outcomes is frequently multidisciplinary. An MM&M conference is useful in its potential to meet ACGME General Competencies, engender a culture of patient safety, and rapidly achieve quality improvement and systems health care delivery initiatives in a large academic medical center.

Trends in estradiol during critical illness are associated with mortality independent of admission estradiol

BACKGROUND

We have previously demonstrated that elevated serum estradiol (E(2)) at intensive care unit (ICU) admission is associated with death in the critically ill, regardless of sex. However, little is known about how changes in initial E(2) during the course of care might signal increasing patient acuity or risk of death. We hypothesized that changes from baseline serum E(2) during the course of critical illness are more strongly associated with mortality than a single E(2) level at admission.

STUDY DESIGN

A prospective cohort of 1,408 critically ill or injured nonpregnant adult patients requiring ICU care for ≥48 hours with admission and subsequent E(2) levels was studied. Demographics, illness severity, and E(2) levels were examined, and the probability of mortality was modeled with multivariate logistic regression. Changes in E(2) were examined by both analysis of variance and logistic regression.

RESULTS

Overall mortality was 14.1% [95% confidence interval (CI) 12.3% to 16%]. Both admission and subsequent E(2) levels were independently associated with mortality [admission E(2) odds ratio 1.1 (CI 1.0 to 1.2); repeat estradiol odds ratio 1.3 (CI 1.2 to1.4)], with subsequent values being stronger. Changes in E(2) were independently associated with mortality [odds ratio 1.1 (CI 1.0 to 1.16)] and improved regression model performance. The regression model produced an area under the receiver operating characteristic curve of 0.80 (CI 0.77 to 0.83).

CONCLUSIONS

Although high admission levels of E(2) are associated with mortality, changes from baseline E(2) in critically ill or injured adults are independently associated with mortality. Future studies of E(2) dynamics may yield new indicators of patient acuity and illuminate underlying mechanisms for targeted therapy.

Increasing blood glucose variability heralds hypoglycemia in the critically ill

BACKGROUND

Control of hyperglycemia improves outcomes, but increases the risk of hypoglycemia. Recent evidence suggests that blood glucose variability (BGV) is more closely associated with mortality than either isolated or mean BG. We hypothesized that differences in BGV over time are associated with hypoglycemia and can be utilized to estimate risk of hypoglycemia (<50 mg/dL).

MATERIALS AND METHODS

Patients treated with intravenous insulin in the Surgical Intensive Care Unit of a tertiary care center formed the retrospective cohort. Exclusion criteria included death within 24 h of admission. We describe BGV in patients over time and its temporal relationship to hypoglycemic events. The risk of hypoglycemia for each BG measurement was estimated in a multivariable regression model. Predictors were measures of BGV, infusions of dextrose and vasopressors, patient demographics, illness severity, and BG measurements.

RESULTS

A total of 66,592 BG measurements were collected on 1392 patients. Hypoglycemia occurred in 154 patients (11.1%). Patient BGV fluctuated over time, and increased in the 24 h preceding a hypoglycemic event. In crude and adjusted analyses, higher BGV was positively associated with a hypoglycemia (OR 1.41, P < 0.001). Previous hypoglycemic events and time since previous BG measurement were also positively associated with hypoglycemic events. Severity of illness, vasopressor use, and diabetes were not independently associated with hypoglycemia.

CONCLUSIONS

BGV increases in the 24 h preceding hypoglycemia, and patients are at increased risk during periods of elevated BG variability. Prospective measurement of variability may identify periods of increased risk for hypoglycemia, and provide an opportunity to mitigate this risk.

Parathyroid carcinoma arising from four-gland hyperplasia

OBJECTIVE

To report the use of immunohistochemical staining for parafibromin, APC, and galectin-3 to evaluate the malignant potential of a resected parathyroid specimen in a patient initially presenting with primary hyperparathyroidism attributable to 4-gland hyperplasia, who subsequently developed metastatic parathyroid carcinoma.

METHODS

We describe a patient with primary hyperparathyroidism who underwent a 3-gland resection of hypercellular parathyroid glands, with postoperative normalization of her serum calcium and parathyroid hormone levels. She returned 4 years later with recurrent hypercalcemia and underwent partial resection of her remaining hypercellular parathyroid gland, without improvement of her hypercalcemia. Selective venous sampling localized the source as draining into her azygos vein, and metastatic parathyroid carcinoma was ultimately diagnosed.

RESULTS

Immunohistochemical staining for parafibromin, APC, and galectin-3 suggested the malignant potential of the atypical adenoma removed during the patient's original operation, which is believed to be the source of her metastatic disease. Access to this information by the treating surgeon may have prompted a more extensive en bloc resection or more vigilant follow-up that could have altered the patient's clinical course.

CONCLUSION

Immunohistochemical staining for parafibromin, APC, and galectin-3 can be used to help distinguish the source of metastatic disease in patients with parathyroid carcinoma. Selective venous sampling may help localize metastatic parathyroid carcinoma when the source is otherwise not apparent.

Infection reduction strategies including antibiotic stewardship protocols in surgical and trauma intensive care units are associated with reduced resistant gram-negative healthcare-associated infections

BACKGROUND

Resistance to broad-spectrum antibiotics by gram-negative organisms is increasing. Resistance demands more resource utilization and is associated with patient morbidity and death. We describe the implementation of infection reduction protocols, including antibiotic stewardship, and assess their impact on multi-drug-resistant (MDR) healthcare-acquired gram-negative infections.

METHODS

Combined infection reduction and antibiotic stewardship protocols were implemented in the surgical and trauma intensive care units at Vanderbilt University Hospital beginning in 2002. The components of the program were: (1) Protocol-specific empiric and therapeutic antibiotics for healthcare-acquired infections; (2) surgical antibiotic prophylaxis protocols; and (3) quarterly rotation/limitation of dual antibiotic classes. Continuous healthcare-acquired infection surveillance was conducted by independent practitioners using National Heath Safety Network criteria. Linear regression analysis was used to estimate trends in MDR gram-negative healthcare-acquired infections.

RESULTS

A total of 1,794 gram-negative pathogens were isolated from healthcare-acquired infections during the eight-year observation period. The proportion of healthcare-acquired infections caused by MDR gram-negative pathogens decreased from 37.4% (2001) to 8.5% (2008), whereas the proportion of healthcare-acquired infections caused by pan-sensitive pathogens increased from 34.1% to 53.2%. The rate of total healthcare-associated infections per 1,000 patient-days that were caused by MDR gram-negative pathogens declined by -0.78 per year (95% confidence interval [CI] -1.28, -0.27). The observed rate of healthcare-acquired infections per 1,000 patient days attributable to specific MDR gram-negative pathogens decreased over time: Pseudomonas -0.14 per year (95% CI -0.20, -0.08), Acinetobacter-0.49 per year (95% CI -0.77, -0.22), and Enterobacteriaceae -0.14 per year (95% CI -0.26, -0.03).

CONCLUSION

Implementation of an antibiotic stewardship protocol as a component of an infection reduction campaign was associated with a decrease in resistant gram-negative healthcare-acquired infections in intensive care units. These results further support widespread implementation of such initiatives.

Guidelines for maintaining a professional compass in the era of social networking

OBJECTIVES

The use of social networking (SN) sites, such as Facebook and Twitter, has skyrocketed during the past 5 years, with more than 400 million current users. What was once isolated to high schools or college campuses has become increasingly ubiquitous in everyday life and across a multitude of industries. Medical centers and residency programs are not immune to this invasion. These sites present opportunities for the rapid dissemination of information from status updates, to tweets, to medical support groups, and even clinical communication between patients and providers. Although powerful, this technology also opens the door for misuse and policies for use will be necessary. We strive to begin a discourse in the surgical community in regard to maintaining professionalism while using SN sites.

RESULTS

The use of SN sites among surgical house staff and faculty has not been addressed previously. To that end, we sought to ascertain the use of the SN site Facebook at our residency program. Of 88 residents and 127 faculty, 56 (64%) and 28 (22%), respectively, have pages on Facebook. Of these, 50% are publicly accessible. Thirty-one percent of the publicly accessible pages had work-related comments posted, and of these comments, 14% referenced specific patient situations or were related to patient care.

CONCLUSIONS

Given the widespread use of SN websites in our surgical community and in society as a whole, every effort should be made to guard against professional truancy. We offer a set of guidelines consistent with the Accreditation Council for Graduate Medical Education and the American College of Surgeons professionalism mandates in regard to usage of these websites. By acknowledging this need and by following these guidelines, surgeons will continue to define and uphold ethical boundaries and thus demonstrate a commitment to patient privacy and the highest levels of professionalism.