Alana Harrington

Safety, effectiveness, and cost effectiveness of long acting versus intermediate acting insulin for patients with type 1 diabetes: systematic review and network meta-analysis

Objective To examine the safety, effectiveness, and cost effectiveness of long acting insulin for type 1 diabetes. Design Systematic review and network meta-analysis. Data sources Medline, Cochrane Central Register of Controlled Trials, Embase, and grey literature were searched through January 2013. Study selection Randomized controlled trials or non-randomized studies of long acting (glargine, detemir) and intermediate acting (neutral protamine Hagedorn (NPH), lente) insulin for adults with type 1 diabetes were included. Results 39 studies (27 randomized controlled trials including 7496 patients) were included after screening of 6501 titles/abstracts and 190 full text articles. Glargine once daily, detemir once daily, and detemir once/twice daily significantly reduced hemoglobin A1c compared with NPH once daily in network meta-analysis (26 randomized controlled trials, mean difference −0.39%, 95% confidence interval −0.59% to −0.19%; −0.26%, −0.48% to −0.03%; and −0.36%, −0.65% to −0.08%; respectively). Differences in network meta-analysis were observed between long acting and intermediate acting insulin for severe hypoglycemia (16 randomized controlled trials; detemir once/twice daily versus NPH once/twice daily: odds ratio 0.62, 95% confidence interval 0.42 to 0.91) and weight gain (13 randomized controlled trials; detemir once daily versus NPH once/twice daily: mean difference 4.04 kg, 3.06 to 5.02 kg; detemir once/twice daily versus NPH once daily: −5.51 kg, −6.56 to −4.46 kg; glargine once daily versus NPH once daily: −5.14 kg, −6.07 to −4.21). Compared with NPH, detemir was less costly and more effective in 3/14 cost effectiveness analyses and glargine was less costly and more effective in 2/8 cost effectiveness analyses. The remaining cost effectiveness analyses found that detemir and glargine were more costly but more effective than NPH. Glargine was not cost effective compared with detemir in 2/2 cost effectiveness analyses. Conclusions Long acting insulin analogs are probably superior to intermediate acting insulin analogs, although the difference is small for hemoglobin A1c. Patients and their physicians should tailor their choice of insulin according to preference, cost, and accessibility. Systematic review registration PROSPERO CRD42013003610.

Complete mapping of the tricuspid valve apparatus using three-dimensional sonomicrometry

OBJECTIVE Many surgeons consider the tricuspid valve to be a second-class structure. Our objective was to determine the normal anatomy and dynamic characteristics of the tricuspid valve apparatus in vivo and to discern whether this would aid the design of a tricuspid valve annuloplasty ring model. METHODS Sixteen sonomicrometry crystals were placed around the tricuspid annulus, at the bases and tips of the papillary muscles, the free edges of the leaflets, and the right ventricular apex during cardiopulmonary bypass in 5 anesthetized York Hampshire pigs. Animals were studied after weaning of cardiopulmonary bypass on 10 cardiac cycles of normal hemodynamics. RESULTS Sonomicrometry array localizations demonstrate the multiplanar shape of the tricuspid annulus. The tricuspid annulus reaches its maximum area (97.9 ± 25.4 mm(2)) at the end of diastole and its minimum area (77.3 ± 22.5 mm(2)) at the end of systole, and increases again in early diastole. Papillary muscles shorten by 0.8 to 1.5 mm (11.2%) in systole, and chordae tendineae straighten by 0.8 to 1.7 mm (11.4%) in systole. CONCLUSIONS The shape of the tricuspid annulus is a multiplanar 3-dimensional one with its highest point at the anteroseptal commissure and its lowest point at the posteroseptal commissure, and the anteroposterior commissure is in a middle plane in between. The tricuspid annulus area reaches its maximum during diastole and its minimum during systole. The papillary muscles contract by the same amount of chordal straightening. The optimal tricuspid annuloplasty ring may be a multiplanar 3-dimensional one that mimics the normal tricuspid annulus.

Sternal plating for primary and secondary sternal closure; can it improve sternal stability?

BackgroundSternal instability with mediastinitis is a very serious complication after median sternotomy. Biomechanical studies have suggested superiority of rigid plate fixation over wire cerclage for sternal fixation. This study tests the hypothesis that sternal closure stability can be improved by adding plate fixation in a human cadaver model.MethodsMidline sternotomy was performed in 18 human cadavers. Four sternal closure techniques were tested: (1) approximation with six interrupted steel wires; (2) approximation with six interrupted cables; (3) closure 1 (wires) or 2 (cables) reinforced with a transverse sternal plate at the sixth rib; (4) Closure using 4 sternal plates alone. Intrathoracic pressure was increased in all techniques while sternal separation was measured by three pairs of sonomicrometry crystals fixed at the upper, middle and lower parts of the sternum until 2.0 mm separation was detected. Differences in displacement pressures were analyzed using repeated measures ANOVA and Regression Coefficients.ResultsIntrathoracic pressure required to cause 2.0 mm separation increased significantly from 183.3 ± 123.9 to 301.4 ± 204.5 in wires/cables alone vs. wires/cables plus one plate respectively, and to 355.0 ± 210.4 in the 4 plates group (p < 0.05). Regression Coefficients (95% CI) were 120 (47–194) and 142 (66–219) respectively for the plate groups.ConclusionTransverse sternal plating with 1 or 4 plates significantly improves sternal stability closure in human cadaver model. Adding a single sternal plate to primary closure improves the strength of sternal closure with traditional wiring potentially reducing the risk of sternal dehiscence and could be considered in high risk patients.

Speckle Tracking for the Intraoperative Assessment of Right Ventricular Function: A Feasibility Study

OBJECTIVES Speckle tracking is an ultrasound method that assesses B-mode features to measure tissue displacement and derive deformation parameters. The objective of this study was to assess the feasibility of using speckle tracking in the measurement of right ventricular (RV) longitudinal strain during cardiac surgery using transesophageal echocardiography (TEE). DESIGN This was a prospective, observational cohort study. SETTING A single university hospital setting. PARTICIPANTS Twenty-one patients without valvular disease referred for coronary artery bypass graft surgery were studied. INTERVENTIONS None. MEASUREMENTS AND MAIN RESULTS After the induction of anesthesia and mechanical ventilation, transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE) were used to obtain tricuspid annular plane systolic excursion (TAPSE), RV fractional area of change (FAC), and 2-dimensional strain analysis (speckle tracking) on 3 consecutive heart beats. There was a larger percentage of measurable segments achieved when using TEE. All segments could be analyzed per cardiac cycle in 73% of loops when using TEE and 38% when using TTE. The global strain value was similar using both methods (TEE: -20.4%, TTE: -20.1%). The TAPSE could be measured in only 52% of the segments using TTE and 100% using TEE. The FAC could be measured in 90.5% of the loops using TEE and in only 33.3% of the loops using TTE. CONCLUSIONS Perioperative measurements of RV strain using TEE in ventilated patients is feasible. The success rate was higher using TEE in ventilated patients under anesthesia. Differences between the 2 methods were likely the result of differences in 2-dimensional image quality.

Seeking effective interventions to treat complex wounds: an overview of systematic reviews

BackgroundNumerous, often multi-faceted regimens are available for treating complex wounds, yet the evidence of these interventions is recondite across the literature. We aimed to identify effective interventions to treat complex wounds through an overview of systematic reviews.MethodsMEDLINE (OVID interface, 1946 until October 26, 2012), EMBASE (OVID interface, 1947 until October 26, 2012), and the Cochrane Database of Systematic Reviews (Issue 10 of 12, 2012) were searched on October 26, 2012. Systematic reviews that examined adults receiving care for their complex wounds were included. Two reviewers independently screened the literature, abstracted data, and assessed study quality using the Assessment of Multiple Systematic Reviews (AMSTAR) tool.ResultsOverall, 99 systematic reviews were included after screening 6,200 titles and abstracts and 422 full-texts; 54 were systematic reviews with a meta-analysis (including data on over 54,000 patients) and 45 were systematic reviews without a meta-analysis. Overall, 44% of included reviews were rated as being of high quality (AMSTAR score ≥8). Based on data from systematic reviews including a meta-analysis with an AMSTAR score ≥8, promising interventions for complex wounds were identified. These included bandages or stockings (multi-layer, high compression) and wound cleansing for venous leg ulcers; four-layer bandages for mixed arterial/venous leg ulcers; biologics, ultrasound, and hydrogel dressings for diabetic leg/foot ulcers; hydrocolloid dressings, electrotherapy, air-fluidized beds, and alternate foam mattresses for pressure ulcers; and silver dressings and ultrasound for unspecified mixed complex wounds. For surgical wound infections, topical negative pressure and vacuum-assisted closure were promising interventions, but this was based on evidence from moderate to low quality systematic reviews.ConclusionsNumerous interventions can be utilized for patients with varying types of complex wounds, yet few treatments were consistently effective across all outcomes throughout the literature. Clinicians and patients can use our results to tailor effective treatment according to type of complex wound. Network meta-analysis will be of benefit to decision-makers, as it will permit multiple treatment comparisons and ranking of the effectiveness of all interventions.Please see related article: http://dx.doi.org/10.1186/s12916-015-0326-3

Effect of oxygen affinity and molecular weight of HBOCs on cerebral oxygenation and blood pressure in rats

PurposeThis study assessed the effect of oxygen affinity and molecular weight (MW) of o-raffinose cross-linked hemoglobin based oxygen carriers (HBOCs) on cerebral oxygen delivery and mean arterial blood pressure (MAP) following hemorrhage and resuscitation in rats.MethodsIsoflurane anesthetized rats (n = 6-7 per group) underwent 30% hemorrhage and resuscitation with an equivalent volume of one of three different HBOCs: 1) High P50 Poly o-raffinose hemoglobin (Poly OR-Hb, P50 = 70 mmHg); 2) High P50 > 128 Poly OR-Hb (MW > 128 kDa, P50 = 70 mmHg) and 3) Low P50 > 128 Poly OR-Hb (MW > 128 kDa, P50 = 11 mmHg). Hippocampal cerebral tissue oxygen tension, regional cerebral blood flow (rCBF), MAP, total hemoglobin concentration and arterial blood gases were measured. Data analysis by two-way ANOVA and post hoc Tukey tests determined significance (P < 0.05, mean ± SD).ResultsHippocampal tissue oxygen tension increased in all HBOC groups following resuscitation. The rCBF remained unchanged after HBOC resuscitation in all groups. Following resuscitation, the peak MAP was higher in the High P50 Poly OR-Hb group ( 152 ± 13 mmHg) when compared to either the Low or High P50 large MW, (> 128 kDa) HBOC group (119 ± 15 mmHg or 127 ± 18 respectively, P < 0.05 for both).ConclusionsO-raffinose polymerized HBOC, with or without lower MW components, maintained cerebral tissue oxygen delivery following hemorrhage and resuscitation in rats. The higher MW HBOCs showed a decrease in peak MAP, which did not alter oxygen delivery. No significant effect of oxygen affinity on cerebral tissue oxygen tension or blood flow was observed.RésuméObjectifÉvaluer l’effet de l’affinité pour l’oxygène et du poids moléculaire (PM) des transporteurs d’oxygène à base d’hémoglobine (TOBH) avec o-raffinose sur l’apport d’oxygène cérébral et la tension artérielle moyenne (TAM) après une hémorragie et une réanimation chez des rats.MéthodeDes rats anesthésiés à l’isoflurane (n = 6-7 par groupe) ont subi une hémorragie à 30% et une réanimation avec un volume équivalent de l’un des trois différents TOBH suivants : 1) de l’hémoglobine Poly o-raffinose à P50 élevé (Poly OR-Hb, P50 = 70 mmHg) ; 2) 128 Poly OR-Hb à P50 élevé (PM > 128 kDa, P50 = 70 mmHg) et 3) 128 Poly OR-Hb à faible P50 (PM > 128 kDa, P50 = 1 1 mmHg). La tension en oxygène du tissu cérébral hippocampique, le débit sanguin cérébral régional (DSCr), la TAM, la concentration d’hémoglobine totale et la gazométrie du sang artériel ont été mesurés. L’analyse de données, par double ANOVA et tests de Tukey ultérieur, ont permis de déterminer la valeur significative (P < 0,05, moyenne ± SD).RésultatsLa tension en oxygène du tissu hippocampique s’est accrue dans tous les groupes de TOBH après la réanimation. Le DSCr est resté le même dans tous les groupes après la réanimation avec les TOBH. Après la réanimation, la TAM était plus élevée dans le groupe Poly OR-Hb à P50 élevé (152 ± 13 mmHg) comparé au groupe de TOBH de P50 élevé et de grand PM, (> 128 kDa) (119 ± 15 mmHg ou 127 ± 18 respectivement, P < 0,05 pour les deux).ConclusionLes TOBH polymérisés avec o-raffinose, avec ou sans composants de faible PM, ont maintenu l’apport d’oxygène au tissu cérébral après une hémorragie et une réanimation chez des rats. Les TOBH de PM élevé ont montré une baisse de la TAM qui n’a pas nui à l’apport d’oxygène. Aucun effet significatif de l’affinité pour l’oxygène sur la tension en oxygène du tissu cérébral ou sur le débit sanguin n’a été observé.

Evaluation of left ventricular reverse remodeling in patients with severe aortic regurgitation undergoing aortic valve replacement: Comparison between diameters and volumes

In patients with severe aortic regurgitation (AR), the left ventricular ejection fraction (LVEF) and left ventricle (LV) size are crucial for determining clinical prognosis and timing of valve intervention. In clinical practice, LV internal diameters obtained at end‐diastole are used to assess the degree of LV dilatation. Whether quantification of LV volumes would provide more robust information as compared to LV linear dimensions is unknown.

Renal expression of endothelial nitric oxide synthase after cpb in rat

INTRODUCTION Acute renal failure is one of the major complications of cardiac surgery and CPB, occurring in approximately 5% of patients. Postoperative renal dysfunction increases the risk of mortality more than 20 fold, and triples the hospitalization costs. Although the mechanism is not clear, lower hematocrit and urine pO2 level are predictive of renal injury, suggesting that reduced oxygen delivery may be important. Hypoxia is known to cause changes in expression of a number of genes, including NOS (nitric oxide synthase) and VEGF (vascular endothelial growth factor). The purpose of this study was to determine if CPB results in hypoxic gene expression in the kidney.