A Novel Anatomic Landmark to Target the Left Ventricle During Chest Compressions in Cardiac Arrest.

Background Resuscitation guidelines recommend that chest compressions be performed over the lower sternum. Current computed tomography and magnetic resonance imaging studies suggest that the current area of compression does not target the left ventricle (LV). Using transthoracic ultrasound, we sought to identify potential anatomic landmarks that would result in compressions over the LV in the majority of our study participants. Methodology We recruited 64 healthy men and women (over the age of 40) from the Simulated Patient Program at the University of Saskatchewan. Using ultrasound, we identified the LV and the associated surface anatomy in terms of intercostal space (ICS) and parasternal or mid-clavicular lines. We also collected biometric data including body mass index, chest circumference, and the corresponding inter-nipple line ICS. Results The LV was located along the left sternal border in 62 (96.9%) participants. The most frequent LV location was along the left sternal border at the sixth ICS in 26 (40.6%) participants, with 13 (20.3%) at the fifth and 10 (15.6%) participants at the seventh ICS. In two (3.1%) participants, the LV was found along the mid-clavicular zone at the fifth ICS. The area from the fifth to seventh ICS on the left sternal border, typically covered by an adult palm centered at the sixth ICS, overlaid 49 of 64 (76.6%, 95% confidence interval [CI]: 64.3-86.2%) identified LV locations. By comparison, centering the heel of the palm over the inter-nipple line at the left sternal border would cover the LV in 46 (71.9%, 95% CI: 59.2-82.4%) participants.  Conclusions A novel area of compression over the left sternal border at the inter-nipple line would result in compressions over the LV in nearly three-quarters of our study participants. Future research should investigate whether this proposed area of compression is applicable to a broader population including those with cardiac and thoracic disease.

Use of a Simple Ultrasound Device to Identify the Optimal Area of Compression for Out-of-Hospital Cardiac Arrest.

Background Despite automated defibrillation and compression-first resuscitation, out-of-hospital cardiac arrest (OHCA) survival remains low. Resuscitation guidelines recommend that chest compressions should be done over the lower half of the sternum, but evidence indicates that this is often associated with outflow obstruction. Emerging studies suggest that compression directly over the left ventricle (LV) may improve survival and outcomes, but rapid and reliable localization of the LV is a major obstacle for those first responding to OHCA. This study aimed to determine if a simplified, easy-to-use ultrasound device (bladder scanner) can reliably locate the heart when applied over the intercostal spaces of the anterior thorax in supine patients. Furthermore, we sought to describe the association between largest scan volumes and underlying cardiac anatomy with particular attention to the long axis of the LV. Methodology We recruited healthy male and female volunteers over 40 years of age. Using a bladder scanner to evaluate the left sternal border and mid-clavicular lines, we determined the maximal scan volumes at 10 intercostal spaces for each participant. Cardiac ultrasound was then used to evaluate the corresponding underlying cardiac anatomy and determine the area overlying the long-axis view of the LV. Descriptive statistics (means with standard deviations [SD], medians with interquartile ranges, and frequencies with proportions) were used to quantify demographic information, typical scan volumes across the chest, the frequencies of the best long-axis LV view location. This was then repeated for left sternal border assessments only. Kappa was determined when evaluating agreement between the largest left sternal border scan volume and the best long-axis LV view location. Results The long-axis LV was the predominant structure underlying the largest scan volume in 39/51 (76.5%) patients. When limited to left sternal border volumes only, the long axis of the LV was underlying the maximum volume intercostal space in 46/51 (90.2%; 95% confidence interval [CI]: 78.6%, 96.7%). The largest left sternal border scan volumes were located over the best long-axis LV view in 39/51 (76.5%, 95% CI: 62.5%, 87.2%) of the study participants with a Kappa statistic of 0.68 (95% CI: 0.52, 0.84; p < 0.0001).  Conclusions In this cross-sectional study of healthy volunteers, an easy-to-use ultrasound device (bladder scanner) was able to reliably localize the heart. Largest scan volumes over the left sternal border showed substantial agreement with the intercostal space overlying the long axis of the LV. Further investigations are warranted to determine if such localization is reliable in cardiac arrest patients.

The translational challenge in the development of new and effective therapies for endometriosis: a review of confidence from published preclinical efficacy studies.

BACKGROUND: Endometriosis is a benign gynaecological condition that presents symptoms of chronic pelvic pain and the ectopic growth of endometrial lesions at sites on the peritoneum. Few new approaches to the management of the disease symptoms and progression have emerged in decades. The cornerstone of developing new therapies is the confidence and translational value placed in the preclinical models used to assess efficacy of emerging approaches. METHODS: We systematically reviewed preclinical efficacy data from rodent and non-human primates, evaluating the effects of an investigational agent or target reported in PubMed between 2000 and 2010. We evaluated the reports for which model and end-points had been used to determine efficacy, whether there was evidence of independent replication, whether techniques had been incorporated into the experimental design to eliminate potential bias and whether there was a confirmation of drug exposure or target engagement in the study. RESULTS: We identified 94 publications that met our criteria for review. Efficacy studies were conducted in a wider range of different models with no clear consensus on which model or end-point has the most translational value. The large majority of studies either did not report what measures were incorporated into the design to address potential bias or account for it or did not confirm whether the specified target was engaged. CONCLUSIONS: Greater scrutiny of the preclinical efficacy models, end-points and experimental designs is needed if the desire of translating novel treatment approaches is to be realized for women with endometriosis.

Evaluation of a convenient method of assessing rodent visual function in safety pharmacology studies: effects of sodium iodate on visual acuity and retinal morphology in albino and pigmented rats and mice.

INTRODUCTION: We have evaluated the ability of a semi-automated, optomotor reflex method to assess drug-induced visual dysfunction, in albino and pigmented rats and mice. METHODS: Male Han Wistar (HW) and Long Evans (LE) rats and mice (CD-1 and C57BL/6) were tested in a chamber formed by 4 computer monitors displaying a rotating vertical grating, to elicit head-tracking movements. The highest visible grating frequency was taken as the threshold of visual acuity, in cycles per degree (c/d). Animals received an intravenous infusion of either sodium iodate (50mg/kg) or 0.9% w/v NaCl (aq). They were tested 2h later, then re-tested daily for a further 3 days. The time course of the effect was assessed in HW rats over a 6-week period, including electron microscopy, and immunohistochemical analysis of markers of injury and repair in the retina. RESULTS: Baseline visual acuities for HW and LE rats were 0.355 ± 0.007 and 0.530 ± 0.004 c/d, respectively, and 0.296 ± 0.003 c/d and 0.370 ± 0.001 c/d for CD-1 and C57BL/6 mice, respectively (n=10 for each). In HW rats there was a dramatic loss of visual acuity 2h after administration of sodium iodate (0.021 ± 0.021 c/d; P<0.001). Less dramatic decreases in visual acuity were seen in LE rats and in the two mouse strains. In HW rats, visual acuity was restored after 4 weeks. This paralleled the histopathological recovery of the peripheral retina, whereas the central retina did not recover. DISCUSSION: The method proved to be very convenient, and the stability of visual acuity in vehicle control rats over a 6-week period also demonstrated its suitability for inclusion in long-term toxicity studies. Both albino and pigmented mice and rats are suitable for assessment of retinotoxicity using this method, but albino rats are the most sensitive to sodium iodate.

Endovascular repair of an actively hemorrhaging stab wound injury to the abdominal aorta.

Traumatic injury of the abdominal aorta is rare and potentially lethal (Yeh et al., J Vasc Surg 42(5):1007-1009, 2005; Chicos et al., Chirurgia (Bucur) 102(2):237-240, 2007) as it can result in major retroperitoneal hemorrhage, requiring an urgent open surgery. In case of concomitant bowel injury or other conditions of hostile abdomen, endovascular repair can be an alternative treatment. This case report deals with a 50-year-old man presenting at the emergency ward with three stab wounds: two in the abdomen and one in the chest. During explorative laparotomy, liver laceration and bowel perforation were repaired. One day later, abdominal CT-scan revealed an additional retroperitoneal hematoma associated with an aortic pseudoaneurysm, located anteriorly 3 cm above the aortic bifurcation. Because of the risk of graft infection, an endovascular repair of the aortic injury using a Gore excluder stent-graft was performed. Radiological and clinical follow-up revealed a gradual shrinkage of the pseudo-aneurysm and no sign of graft infection at two years' follow-up.