Faculty Bibliography

Learning Objective #1: Recognize the incidence of posterior circulation stroke after cardiac catheterization Learning Objective #2: Recognize how cognitive biases affect clinical decision making CASE: A 57 year old man with hypertension, type 2 diabetes, depression, coronary artery disease s/p PCI and 4-vessel CABG presented with nausea, vomiting, and syncope. He was found to be in complete heart block and underwent emergent pacemaker placement and cardiac catheterization with stent placement to the left circumflex artery. After catheterization, patient reported lightheadedness and cloudiness when walking. He was transferred to the medicine service with sign-out to follow up with physical therapy given "deconditioning" after his acute illness. PT sessions were limited by his hesitancy to walk beyond a few steps. Four days after downgrade, patient reported left sided visual changes. Physical exam was notable for left homon-ymous hemianopia without somatosensory deficits. A non-contrast head CT revealed a new acute to sub-acute right posterior cerebral artery infarction. He was determined to have had an embolic ischemic stroke secondary to cardiac catheterization. His lightheadedness and cloudiness were believed to be secondary to hemianopia. He was medically managed and discharged to SAR. IMPACT: This case involves a common post-catheterization complication as an unusual presentation described as lightheadedness and cloudiness. We attributed the symptoms to overall deconditioning secondary to diagnostic momentum. Furthermore, visual fields were not accurately assessed in this post-procedure patient. Our personal practice now includes exam maneuvers to evaluate posterior circulation on patients post-cardiac catheterization given the high incidence of these strokes in cardiac patients. DISCUSSION: Post-cardiac catheterization strokes are common, with most occurring within 24 hours of the procedure. Of these, approximately 25% involve the posterior circulation often leading to visual field deficits without gross somatosensory deficits. As a result, neurological deficits may often go unnoticed if visual fields are not accurately assessed. Furthermore, patients may not realize a true visual field deficit as they can compensate with neck rotation; initial descriptors may be vague such as lightheadedness or cloudiness. Our case was further complicated by cognitive biases that influenced our decision making; namely, the case was framed as overall deconditioning. As a result, we anchored to a single diagnosis and did not consider neurological deficit as an explanation for our patient's symptoms. We encourage all medical professionals to be cognizant of variability in presentation of visual field deficits and also be keen to their own cognitive biases

OBJECTIVE:In the United States, hepatocellular carcinoma (HCC) is more common among communities with low socioeconomic status (SES), and these groups tend to be diagnosed with later-stage cancers. Sorafenib is the primary treatment for advanced HCC, however its substantial cost raises concern for access to treatment. METHODS:The newly developed Case-Background method was used to estimate odds ratios for the impacts of various sociodemographic factors on sorafenib access in clinically eligible patients. Socioeconomic status was defined as a factor of median income and education level based on ZIP code of residence. RESULTS:There was a strong association between sorafenib prescription and residence in an area of higher SES. While controlling for age, race/ethnicity, and insurance status, high SES residence doubled the odds of sorafenib prescription (OR=2.05, p<.01). CONCLUSIONS:Low socioeconomic status communities appear to have a reduced chance of receiving the only effective treatment for advanced HCC.

BACKGROUND:Hyaluronic acid (HA), an extracellular matrix component, is degraded in response to local tissue injury or stress. In various animal models of lung injury, HA has been shown to play a mechanistic role in modulating inflammation and injury. While HA is present in the lungs of patients with acute respiratory distress syndrome (ARDS), its relationship to patient outcomes is unknown. METHODS:We studied 86 patients with ARDS previously enrolled in the Phase II Randomized Trial of Fish Oil in Patients with Acute Lung Injury (NCT00351533) at five North American medical centers. We examined paired serum and bronchoalveolar lavage fluid (BALF) samples obtained within 48 hours of diagnosis of ARDS. We evaluated the association of HA levels in serum and BALF with local (lung injury score (LIS)) and systemic (sequential organ failure assessment score (SOFA)) measures of organ dysfunction with regression analysis adjusting for age, sex, race, treatment group, and risk factor for ARDS. RESULTS:We found that both day-0 circulating and alveolar levels of HA were associated with worsening LIS (p = 0.04 and p = 0.003, respectively), particularly via associations with degree of hypoxemia (p = 0.02 and p < 0.001, respectively) and set positive end-expiratory pressure (p = 0.01 and p = 0.02, respectively). Circulating HA was associated with SOFA score (p < 0.001), driven by associations with the respiratory (p = 0.02), coagulation (p < 0.001), liver (p = 0.006), and renal (p = 0.01) components. Notably, the alveolar HA levels were associated with the respiratory component of the SOFA score (p = 0.003) but not the composite SOFA score (p = 0.27). CONCLUSIONS:Elevated alveolar levels of HA are associated with LIS while circulating levels are associated with both lung injury and SOFA scores. These findings suggest that HA has a potential role in both local and systemic organ dysfunction in patients with ARDS.

Obesity continues to increase in prevalence worldwide. Hypertension has long been associated with obesity, and weight loss continues to be a first-line therapy in the treatment of hypertension. Lifestyle modification and pharmacologic therapy, however, often meet with treatment failure. Bariatric surgery continues to be the most successful approach to sustained weight loss. This review focuses on the underlying physiologic mechanisms of obesity-hypertension, and the impact of bariatric surgery on the treatment of hypertension. Current available literature on the physiologic mechanisms of obesity-hypertension, and the major trials, meta-analyses and systematic reviews of the impact of bariatric surgery procedures on hypertension are reviewed. Evidence suggests significant improvement in obesity-hypertension in patients who undergo surgical weight-reduction procedures. Malabsorptive techniques such as the Roux-en-Y gastric bypass or surgical resection techniques such as laparoscopic sleeve gastrectomy appear to offer superior results in regards to hypertension control over restrictive techniques such as Gastric Banding. Though long-term control of hypertension following surgery remains a concern, available follow-up post-operative data of up to 10 years suggests a sustained, if lessened, effect on hypertension control over time.

The plasmid-encoded colistin resistance gene (mcr-1) has recently been reported in various Gram-negative species. However, the expression profile of mcr-1 remains unknown. Here, we investigated the expression of mcr-1 in various plasmids and bacteria. The mcr-1 expression levels in pMCR1_IncX4 varied from 1.81 × 10^-5 to 1.05 × 10^-4 (pmol per μg total RNA) in the two K. pneumoniae strains SZ03 and SZ04 (ST25) and the two E. coli strains SZ01 and CDA6 (ST2448 and ST167, respectively). The mcr-1 expression levels of pMCR1_IncI2 in E. coli SZ02 (ST2085) and E. coli BJ13 (ST457) were 5.27 × 10^-5 and 2.58 × 10^-5, respectively. In addition, the expression of chromosomal mcr-1 in ST156 E. coli BJ10 was 5.49×10^-5. Interestingly, after 4μg/ml colistin treatment, mcr-1 in pMCR1_IncX4 increased 2- and 4-fold at 20 and 120 mins, respectively, in all pMCR1_IncX4-harboring strains, except for ST2448 E. coli, which had a lower expression after 20 mins that restored to baseline levels after 120 mins. In contrast, mcr-1 expression of pMCR1_IncI2 in the two E. coli strains (SZ02, BJ13) and the chromosomal mcr-1 in E. coli (BJ10) remained at baseline levels after 20 and 120 mins. In the same genetic background host strain E. coli E600, mcr-1 expression of pMCR1_IncX4 and pMCR1_IncI2 were similar and were decreased after colistin treatment for 20 min. However, mcr-1 in pMCR1_IncX4 was up-regulated after colistin treatment for 120 min, while mcr-1 in pMCR1_IncI2 was down-regulated compared to the untreated control. Our results suggested that mcr-1 has distinct expression profiles on different plasmids, bacterial hosts, and after antibiotic treatment.