Analysis of interventions to reduce the incidence of Clostridium difficile infection at a London teaching hospital trust, 2003-2011

BACKGROUND

Since 2008 there has been a substantial fall in the incidence of Clostridium difficile infection (CDI) in the UK, though it is unclear what contribution local and governmental interventions have made to this reduction.

AIM

To assess the value of retrospective analysis using a segmented regression model and single factor analysis of variance (ANOVA) in assessing the impact of interventions to reduce hospital-acquired CDI.

METHODS

A retrospective time-series analysis of 28 interventions implemented over an eight-year period by a large teaching hospital trust. Single factor ANOVA was used to analyse the association between CDI rates and changes in antibiotic usage and hand hygiene compliance data.

FINDINGS

Whereas several interventions were associated with a reduction in CDI rates, insufficient time-points were available between interventions to allow meaningful interpretation of all the data. Reduction of cephalosporin and quinolone use was associated with reduction in CDI rates. There was little association between observed variations in hand hygiene compliance and CDI rates.

CONCLUSION

Though several interventions were associated with a reduction in CDI, this study illustrates the inherent limitations of retrospective time-series methodology for the investigation of infection control measures where large numbers of interventions are introduced over a short time-period. Single factor ANOVA demonstrated an association between fall in CDI and restriction of high-risk antibiotic use. Little association was demonstrated between compliance rates documented in hand hygiene audits and CDI, though compliance was relatively high throughout the period of study.

Extracorporeal life support as rescue strategy for out-of-hospital and emergency department cardiac arrest

BACKGROUND

Extracorporeal life support (ECLS) has been utilized as a rescue strategy for patients with cardiac arrest unresponsive to conventional cardiopulmonary resuscitation.

OBJECTIVE

We sought to describe our institution's experience with implementation of ECLS for out-of-hospital and emergency department (ED) cardiac arrests. Our primary outcome was survival to hospital discharge.

METHODS

Consecutive patients placed on ECLS in the ED or within one hour of admission after out-of-hospital or ED cardiac arrest were enrolled at two urban academic medical centers in the United States from July 2007-April 2014.

RESULTS

During the study period, 26 patients were included. Average age was 40±15 years, 54% were male, and 42% were white. Initial cardiac rhythms were ventricular fibrillation or pulseless ventricular tachycardia in 42%. The average time from initial cardiac arrest to initiation of ECLS was 77 ± 51 min (range 12-180 min). ECLS cannulation was unsuccessful in two patients. Eighteen (69%) had complications related to ECLS, most commonly bleeding and ischemic events. Four patients (15%) survived to discharge, three of whom were neurologically intact at 6 months.

CONCLUSION

ECLS shows promise as a rescue strategy for refractory out-of-hospital or ED cardiac arrest but is not without challenges. Further investigations are necessary to refine the technique, patient selection, and ancillary therapeutics.

Comparison of tongue muscle characteristics of preterm and full term infants during nutritive and nonnutritive sucking

BACKGROUND

Independent oral feeding requires coordination of suck, swallow and breathe and the lingual musculature plays a significant role in this coordinative action. However, clinical benchmarks of lingual function fundamental to successful feeding have not been explored.

AIMS

The present study tests our model for quantifying infant lingual force and size and compares the muscle measures of interest in two cohorts: healthy full-term infants (FT) (N=5) and healthy preterm infants (PT) (N=6).

METHOD

Using an instrumented pacifier and bottle nipple, we determined the resultant compressive forces applied to the nipple by the tongue during nutritive (NS) and nonnutritive sucking (NNS). Muscle size was estimated from measures of posterior tongue thickness using ultrasonography.

RESULTS

After controlling for weight and post menstrual age, statistically significant differences were found between FT and PT infants beginning to feed for NNS frequency and NS tongue force. Clinically significant differences were detected for NNS tongue force and posterior tongue thickness. Additionally, PT infants demonstrated a significant difference in mean tongue force between NS and NNS and FT infants did not. FT infants demonstrated a significant difference in mean frequency between NS and NNS and PT infants did not. Linear regression indicated that mean posterior tongue thickness alone predicted 55% of the variance in NS force.

CONCLUSIONS

Results demonstrate the feasibility of our approach and suggest that infant tongue muscle characteristics necessary for successful feeding differ between healthy full term infants and preterm infants who are beginning oral feeding.

Root stabilization of the repaired bicuspid aortic valve: subcommissural annuloplasty versus root reimplantation

BACKGROUND

At our institution, type I bicuspid aortic valve (BAV) patients with aortic insufficiency (AI) who are candidates for valve preservation are stratified into two groups by aortic root pathology: nonaneurysmal root undergoing primary cusp repair+subcommissural annuloplasty (repair group) vs aneurysmal root undergoing primary cusp repair+root reimplantation (reimplantation group). We report outcomes of this surgical reconstructive strategy for the repaired type I BAV.

METHODS

A retrospective review was performed of 71 patients with a type I BAV undergoing primary valve repair from 2005 to 2012. The repair group (n=40) underwent annular stabilization by subcommissural annuloplasty, and the reimplantation group (n=31) underwent robust annular stabilization provided by root reimplantation.

RESULTS

Preoperative characteristics and root anatomy were similar, except for increased root dimensions in the reimplantation group (p<0.001). Mortality, stroke, valve reoperation, and pacemaker requirement were zero in both groups. Postoperative peak (19±10 vs 11±5 mm Hg, p<0.001) and mean gradients (10±5 vs 5±3 mm Hg, p<0.001) favored root reimplantation. Freedom from AI greater than 1+ was 100% in both groups. Mean follow-up was 40 months in the reimplantation group and 38 months in the repair group. At 5 years, overall survival was 100% in both groups. Freedom from aortic reoperation and AI exceeding 2+ were similar in both groups. Freedom from AI exceeding 1+ was significantly better in the reimplantation group (92%±6% vs 62%±10%, p=0.03). The 2-year peak (14±6 vs 19±9 mm Hg, p=0.009) and mean (7±4 vs 11±5 mm Hg, p=0.001) gradients favored root reimplantation.

CONCLUSIONS

Root stabilization with the reimplantation technique significantly improves the durability of the repaired type I BAV compared with subcommissural annuloplasty. It also provides improved and sustained valve mobility (transvalvular gradients).

Elevated first trimester PAPP--a is associated with increased risk of placenta accreta

OBJECTIVES

The objective of this article is to determine whether there were differences in first trimester serum analytes between cases of placenta previa with and without accreta.

METHODS

Cases of placenta previa in which the patient had first trimester aneuploidy screening were identified. Pregnancy-associated plasma protein A (PAPP-A) and free beta human chorionic gonadotropin (fbhCG) MoMs were compared with those with an accreta. Accreta cases were also compared with published distributions to determine significance and to develop likelihood ratios based on MoM values.

RESULTS

Eighty-two cases of previa were identified, including 16 with a histological diagnosis of placenta accreta. The median PAPP-A MoM of 1.68 in accreta was significantly greater than that of 0.98 in non-accreta (P = 0.002). For fbhCG, the median MoM was 1.00 and 1.01 in accreta and non-accreta, respectively. Of the 16 patients with accreta, 14 (87.5%, 95% confidence interval: [61.6%, 98.4%]) had PAPP-A MoM above 1.0. Six of 16 (37.5%) accreta cases were above the 90th percentile of the unaffected distribution. The likelihood ratios for accreta were 0.5, 2.0, and 3.0. PAPP-A MoMs were 0.19, 2.11, and 4.27, respectively.

CONCLUSIONS

First trimester PAPP-A levels may be useful in identifying pregnancies at high risk for placenta accreta. Larger studies could incorporate both clinical and biochemical data into a risk algorithm.

Type I and Type II hybrid aortic arch replacement: postoperative and mid-term outcome analysis

BACKGROUND

Hybrid aortic arch replacement has emerged as a safe treatment modality for arch aneurysms, especially in patients of old age and with greater comorbid burden. We assessed our institutional outcomes in patients undergoing Types I and II hybrid aortic arch replacement.

METHODS

From 2005 to 2012, 685 patients underwent thoracic endovascular repair (TEVAR), of whom 104 had hybrid arch repair (open + endovascular approach). 47 of these patients had treatment for aortic arch aneurysm ± proximal ascending aortic aneurysm. The hybrid repair entailed aortic arch vessel debranching and concomitant/delayed antegrade ± retrograde TEVAR stent grafting of the arch. Type III patients were excluded from the analysis. Data was prospectively maintained.

RESULTS

28 patients had Type I repair, 8 had Type II repair, and 11 had Type III repair. Mean age was 71±8 years. Primary aortic pathology was aneurysm (81%), followed by chronic arch dissection (11%). 14% of patients required reoperative cardiac surgery. Stent graft deployment rate was 100% after arch vessel debranching. Postoperative endoleak rate was zero. Average cardiopulmonary bypass time was 215±64 minutes, with crossclamp time of 70±55 minutes, and circulatory arrest time of 50±17 minutes. Paraplegia rate was 5.5% (n=2), with stroke rate of 8% (n=3) and renal failure rate of 3% (n=1) requiring hemodialysis. In-hospital mortality was 8% (n=3). Mean length of stay was 17.2±14 days. Median follow-up was 30±21 months. Freedom from all-cause mortality was 71%, 60%, and 48% at 1, 3, and 5 years respectively. Aortic reoperation rate was 2.7% (n=1). No patient had Type I or III endoleak at follow-up. Freedom from mortality was improved in cases performed more recently (July 2008 to 2012) than during our early experience (2005 to June 2008) (81% versus 44% at 3 years, P=0.05).

CONCLUSIONS

Hybrid aortic arch replacement can be performed with good postoperative and midterm results in a cohort of old patients with significant comorbidity. With greater experience, early and midterm outcomes continue to improve. The hybrid arch technique may represent a technical advancement in the field of aortic arch surgery.

Type II arch hybrid debranching procedure

Management of aortic arch aneurysm and dissection continues to evolve as endovascular options play an increasing role in treating thoracic aortopathies. Although conventional open treatment of aortic arch disease with total arch replacement still remains the gold standard, in patients with old age and/or high comorbid disease index, there is significant associated morbidity and mortality. The hybrid arch procedure, which aims to minimize cardiopulmonary bypass and circulatory arrest times, is a particularly appealing surgical option in this cohort of patients. The hybrid arch concept essentially entails three main principles: (I) open debranching of the great vessels; (II) creation of proper proximal (zone 0 landing) and distal landing zones, and; (III) concomitant or delayed endovascular stent grafting of the aortic arch. The classification scheme for hybrid arch debranching procedures is based on the extent of proximal and distal landing zone reconstruction required, and thus the need and extent of cardiopulmonary bypass and circulatory arrest management strategies to be employed. In this illustrated article, we describe the details of the type II hybrid arch debranching procedure, where the ascending aorta and aortic arch pathology is typically treated by reconstruction of ascending aorta ﹢ arch vessel debranching, with concomitant antegrade stent grafting of the aortic arch.