Experimental exploration of dynamic phase transitions and associated metamagnetic fluctuations for materials with different Curie temperatures

We study dynamic magnetic behavior in the vicinity of the dynamic phase transition (DPT) for a suitable series of samples that have different Curie temperatures T_{C}, which thus enables us to experimentally explore the role of the reduced temperature T/T_{C} in the DPT. For this purpose, we fabricate Co_{1-x}Ru_{x} epitaxial thin films with uniaxial in-plane anisotropy by means of sputter deposition in the concentration range 0.0≤x≤0.26. All samples are ferromagnetic at room temperature, exhibit an abrupt magnetization reversal along their easy axis, and represent a unique T_{C} and thus T/T_{C} ratio according to their Ru concentration. The dynamic magnetic behavior is measured by using an ultrasensitive transverse magneto-optical detection method and the resulting dynamic states are explored as a function of the applied magnetic field amplitude H_{0} and period P, as well as an additional bias field H_{b}, which is the conjugate field of the dynamic order parameter Q. Our experimental results demonstrate that the qualitative behavior of the dynamic phase diagram is independent of the T/T_{C} ratio and that for all T/T_{C} values we observe metamagnetic anomalies in the dynamic paramagnetic state, which do not exist in the corresponding thermodynamic phase diagram. However, quantitatively, these metamagnetic anomalies are very strongly dependent on the T/T_{C} ratio, leading to an about 20-fold increase of large metamagnetic fluctuations in the paramagnetic regime as the T/T_{C} ratio increases from 0.37 to 0.68. Also, the phase space range in which these anomalous metamagnetic fluctuations occur extends closer and closer to the critical point as T/T_{C} increases.

General anesthesia during atrial fibrillation ablation: Standardized protocol and experience

BACKGROUND

Most atrial fibrillation (AF) ablations are performed with general anesthesia (GA). The ideal GA protocol is unknown, but it affects ablation outcomes and laboratory utilization. We sought to report a GA protocol used at a high-volume center, with special consideration on efficiency and optimization of mapping and ablation conditions.

METHODS

Our protocol consists of propofol as sole anesthetic agent and analgesia with Fentanyl. IV fluids are minimized. After transseptal access, the right phrenic nerve is tagged, rocuronium is given, and redosing avoided. Ventilation is modulated to optimize mapping and ablation. After ablation, isoproterenol is infused for 20 min. After 10 min, propofol is gradually decreased and ventilation set to SIMV 8 breaths/min to promote spontaneous breathing, and then switched to pressure support and propofol stopped. Paralysis is reversed and furosemide given. Patient is extubated once meeting standard criteria.

RESULTS

A total of 1286 patients underwent AF ablation from January 2017 to December 2018 using the protocol. Mean age was 66 years (41% paroxysmal AF, CHADS2Vasc 2.6). Total procedure time was 86 min. Median time to extubation was 9 min (first and third quartile 6-16) after procedure completed, with total anesthesia time of 116 min. On average 370 mL of fluids were given by anesthesia. Only one patient who had heart failure required reintubation with no other anesthesia-related complications seen.

CONCLUSION

Our GA protocol was specifically designed for AF ablation. It was safe and led to efficient recovery and extubation times. It maximizes laboratory utilization time without compromising safety.

A real-life analysis on the indications and prognostic relevance of perioperative chemotherapy in locally advanced resectable gastric adenocarcinoma

BACKGROUND AND PURPOSE

Perioperative chemotherapy (periCTX) based on the "MAGIC" scheme has become a standard treatment in Europe for locally advanced oesophagogastric cancer. We assessed implementation and long-term oncological outcomes of MAGIC periCTX for locally advanced gastric cancer.

METHODS

Population-based cohort study of all patients with locally advanced gastric cancer undergoing surgical resection with curative intent in Catalonia and Navarra (the first two autonomous communities included in the EURECCA Upper GI Spanish Working Group) between January 2011 and December 2013. The main variable was the percentage of patients treated with MAGIC periCTX. Kaplan-Meier analysis and Cox proportional hazards model were used to assess the survival benefit of periCTX.

RESULTS

Among 814 patients, 217 (26.6%) received periCTX (especially patients more likely to receive it: aged < 70 years, with proximal tumors, low anesthetic risk, and cT3-4/cN+ clinical stage). 35% did not complete perioperative chemotherapy, with no relationship with age. PeriCTX showed no effect on postoperative morbimortality. Histological tumor regression was more often absent or poor (38.2%) than total or almost total (27.8%), although clinico-pathological lymph-node downstaging was higher than expected by staging inaccuracy (38.7% vs. 24.2%). PeriCTX was associated with a better survival only in cT3-4 and cN+ patients, showing less prognostic relevance than optimal oncological surgery with D2 lymphadenectomy.

CONCLUSIONS

Only 26.6% of locally advanced resectable gastric cancer patients received PeriCTX. Pathological response was poor, although some degree of nodal downstaging was observed. Survival benefit of periCTX was limited to cT3-4 and cN+ patients, being less relevant than D2 lymphadenectomy.

P2835Feasibility and safety of same day discharge after radiofrequency catheter ablation for paroxysmal atrial fibrillation

Background

Atrial fibrillation catheter ablation (CA) is the most frequent arrhythmia ablation and accounts for a significant proportion of treatment cost. Same day discharge (SDD) after paroxysmal atrial fibrillation (PAF) ablation is an attractive strategy for both patients and hospitals.

Objective

To understand the eligibility criteria and outcomes for PAF patients who can safely undergo same day discharge after radiofrequency catheter ablation.

Methods

Patients undergoing CA for PAF were evaluated for SDD at a pre-procedure visit to assess the risk of groin, respiratory, cardiac or bleeding complications. Eligibility criteria for SDD were stable anticoagulation and absence of bleeding history, systolic/diastolic heart failure, or interventional procedures within 60 days, with recommended BMI <35. Patient proximity to the hospital was also considered. Anesthesia included propofol with endotracheal intubation and all patients were ablated with a porous tip contact force catheter (STSF). Patients were on bed rest for 6 hours post-procedure, then ambulated intermittently for 1–2 hours. Discharge followed if they were stable with no evidence of vascular access complications or bleeding. A dedicated RN telephoned patients the following morning to ask a series of standard questions designed to elicit evidence of any complications.

Results

52 procedures were identified for SDD, with 7 patients declining. 45 planned SDD procedures for 43 patients occurred 4/17–6/18. Average age was 57±11 years and CHA2DS2-VASc was 1.5±1.1 at procedure. Procedure time was 69±26 min (IQR: 49 - 84 min) with maximum fluoroscopy usage of 0.2 min and 508±149 mL of fluid infused through the catheter. Two patients stayed overnight due a groin bleed and atelectasis with fever, and one chose to stay for comfort. The remaining 42 discharges occurred after 7.2±1.0 hours in recovery, with no SDD-related complications and no required return visits after the follow-up call. There were 3 AF recurrences (6.7%) as of the 10 week visit.

Conclusion

Appropriate low risk patients identified by simple clinical criteria can be safely discharged the same day after CA of PAF. Further evaluation is required for higher risk patients.

Acknowledgement/Funding

The study was funded by Biosense Webster Inc.

Single Day Observational Experience at High Volume Ablation Programs: What is the Impact to Practicing Electrophysiologists?

Introduction

Significant improvements in catheter technology, electro-anatomic (EA) mapping and techniques to reduce fluoroscopy during radiofrequency ablation (RFA) of atrial fibrillation (AF) are on-going.However, few educational opportunities are available post fellowship for Electrophysiologists (EPs) to understand and integrate them into their practice, preventing wide spread adoption. The impact of observational learning for adoption of new technologies and techniques in the field of cardiac electrophysiology has not been studied. We sought to report the impact of a visit to a high-volume center with experience in new technologies and fluoroscopy reductionto the clinical practice of EPs.

Methods

Between 8/2014 and 10/2017 a total of 150 EPs visited 3 hospitals that perform a high volume of AF RFAs. EPs observed a minimum of 4 RFAs, primarily AF. AF RFAs were performed without fluoroscopy, using Carto 3 Version 4 (Biosense Webster) and intracardiac Echocardiography. There was ample interaction and discussion between hosting and visiting EP.

Results

73 EPs (48.6% of visitors) completed an electronic survey after the visit. The majority reported a significant reduction in fluoroscopy (>50%) and procedure (>20%).68% adopted a rigorous workflow and reported an increase in their confidence level with intracardiac echo (79%), continuous mapping (52%) and the Visitag module (61%).

Conclusions

Observational experience can have an immense impact on the clinical practice of EPs. Further effort should be devoted to such programs and to study in a more systematic way their ultimate impact on patient care.

Prevalence of labrum and articular cartilage injuries of the hip on 3T magnetic resonance imaging of asymptomatic elite soccer players

OBJECTIVE

To establish the prevalence of lesions of the labrum and articular cartilage of the hip in asymptomatic elite soccer players by performing 3T magnetic resonance imaging.

METHODS

Eighty-four asymptomatic hips of 42 professional soccer players were evaluated. Male subjects older than 18 years were included. Cam and pincer deformity were defined as an alpha angle greater than 55 degrees and a lateral centre edge angle greater than 39 degrees, respectively. Labral injuries were classified with the Czerny classification and cartilage damage was classified with the Outerbridge classification. Specific statistical tests were used to establish the relationship between anatomical variances of the hip and the presence of chondral and labral injuries.

RESULTS

FAI morphology prevalence was 25%. Abnormalities such as cam (22.5%) and labral injuries (33.8%) were found. Those cases with reported labral injury were predominantly intrasubstance damage (18.8%). Anatomical features of FAI were found to be related to lesions of the femoral cartilage (P<.001), chondrolabral damage (P=.042), or both injuries (P<.001).

CONCLUSION

Asymptomatic labral or cartilaginous injuries of the hip were reported in 25% of the included professional soccer players. These injuries were associated with anatomical features of FAI.

Cost minimization analysis of catheter ablation for paroxysmal atrial fibrillation by catheter technology

AIM

Compare the 1-year costs of three catheter ablation technologies for the treatment of paroxysmal atrial fibrillation (PAF).

MATERIALS & METHODS

A decision tree model was developed to estimate 1-year hospital costs associated with an index and potential repeat PAF ablation procedure using the Thermocool^® Smarttouch^® Catheter (ST), Thermocool SF Catheter (SF) or Arctic Front Advance Cryoballoon (CB). Model parameters were estimated using the results of two recently published studies.

RESULTS

The ST resulted in average per-patient savings for combined inpatient and outpatient populations of US$1488 and US$4494 compared with SF and  CB, respectively. These cost savings were greater in the inpatient setting.

CONCLUSION

The 1-year expected hospital visit costs for PAF ablation were lower with ST than with SF or CB.

Gains in Paroxysmal Atrial Fibrillation Ablation Using a Standardized Workflow to Optimize Contact Force Technologies

Background

Catheter ablation technology has evolved rapidly in recent years. There is a need to understand the impact of these advances on efficiency, safety, and effectiveness in real-world populations. The objective of this study was to evaluate a standardized workflow that integrates a contact force (CF) catheter and stability module in an attempt to optimize efficiency and clinical outcomes of paroxysmal atrial fibrillation (PAF) ablation, and to compare the outcomes of this workflow with existing ablation technologies at a high-volume center.

Methods

Consecutive ablations for PAF from July 2013 - June 2016 were included. Radiofrequency (RF) ablations were performed with the ThermocoolSF Catheter (SF) through April 2014, after which a change was made to the ThermocoolSmarttouchCatheter (ST)with a standardized workflow. Cryoballoon ablations (CA) were performed with theArctic FrontAdvancebetween July 2013 and March 2016. Systematic collection of 12-month effectiveness data began in July 2014. Prior to that time, only acute outcomes and reablations were captured.

Results

Procedural data for 32 SF, 232 ST, and 59 CA procedures for PAF were available. Mean procedure times were similar across SF and CA, and moderately shorter with ST (p=0.0201). Fluoroscopy times were substantially reduced with ST (p<0.0001). Complication rates were low and similar across all cohorts (p=0.4744), whereas reablation rates were lowest in the ST cohort (p=0.0194).

Conclusions

PAF ablation using integrated CF and catheter stability technology with a systematic ablation workflow maylead to improvements in both procedural efficiency and reablation rates, without compromising patient safety.

International Nosocomial Infection Control Consortium report, data summary of 50 countries for 2010-2015: Device-associated module

BACKGROUND

We report the results of International Nosocomial Infection Control Consortium (INICC) surveillance study from January 2010-December 2015 in 703 intensive care units (ICUs) in Latin America, Europe, Eastern Mediterranean, Southeast Asia, and Western Pacific.

METHODS

During the 6-year study period, using Centers for Disease Control and Prevention National Healthcare Safety Network (CDC-NHSN) definitions for device-associated health care-associated infection (DA-HAI), we collected prospective data from 861,284 patients hospitalized in INICC hospital ICUs for an aggregate of 3,506,562 days.

RESULTS

Although device use in INICC ICUs was similar to that reported from CDC-NHSN ICUs, DA-HAI rates were higher in the INICC ICUs: in the INICC medical-surgical ICUs, the pooled rate of central line-associated bloodstream infection, 4.1 per 1,000 central line-days, was nearly 5-fold higher than the 0.8 per 1,000 central line-days reported from comparable US ICUs, the overall rate of ventilator-associated pneumonia was also higher, 13.1 versus 0.9 per 1,000 ventilator-days, as was the rate of catheter-associated urinary tract infection, 5.07 versus 1.7 per 1,000 catheter-days. From blood cultures samples, frequencies of resistance of Pseudomonas isolates to amikacin (29.87% vs 10%) and to imipenem (44.3% vs 26.1%), and of Klebsiella pneumoniae isolates to ceftazidime (73.2% vs 28.8%) and to imipenem (43.27% vs 12.8%) were also higher in the INICC ICUs compared with CDC-NHSN ICUs.

CONCLUSIONS

Although DA-HAIs in INICC ICU patients continue to be higher than the rates reported in CDC-NSHN ICUs representing the developed world, we have observed a significant trend toward the reduction of DA-HAI rates in INICC ICUs as shown in each international report. It is INICC's main goal to continue facilitating education, training, and basic and cost-effective tools and resources, such as standardized forms and an online platform, to tackle this problem effectively and systematically.

Risk factors for candidemia in non-neutropenic critical patients in Colombia

OBJECTIVES

Due to the increase in isolation of Candida spp. in critically ill patients, and the high mortality and economic costs which this infection entails, a study was made of the risk factors associated to candidemia in critically ill patients from 7 intensive care units in Colombia.

MATERIALS AND METHODS

A multicenter matched case-control study was conducted in 7 intensive care units of 3 university hospitals. Data on overall length of hospital stay (including both general wards and the intensive care unit) were recorded.

RESULTS

A total of 243 subjects (81 cases and 162 controls) between January 2008 and December 2012 were included. In order of frequency, C. albicans, C. tropicalis and C. parapsilosis were isolated. The main identified risk factors were: overall length of hospital stay>25 days (OR 5.33, 95% CI 2.6-10.9), use of meropenem (OR 3.75, 95% CI 1.86-7.5), abdominal surgery (OR 2.9, 95% CI 1.39-6.06) and hemodialysis (OR 3.35, 95% CI 1.5-7.7). No differences in mortality between patients with candidemia and controls were found (39.5 vs. 36.5%, respectively, P=.66) were found.

CONCLUSIONS

In Colombia, a long hospital stay, abdominal surgery, the use of meropenem and hemodialysis were identified as risk factors for candidemia.

Long-term outcomes of minor troponin elevations in the intensive care unit

The aim of our study is to determine the short-term and long-term outcomes of intensive care unit (ICU) patients with minor troponin elevations. The retrospective study compared ICU patients with peak troponin elevation less than 0.1 ng/ml to those with only negative tests during their hospital stay. Data were gathered from ICUs at Beth Israel Deaconess Medical Center between 2001 and 2008. A total of 4224 patients (2547 controls and 1677 positives) were analysed. The primary outcome was mortality at one year. Secondary outcomes were 30-day mortality and hospital and ICU lengths of stay. After adjusting for age, sex, Simplified Acute Physiology Score, Sequential Organ Failure Assessment and combined Elixhauser score, we found that minor troponin elevations (peak troponin elevation between 0.01 and 0.09 ng/ml) were associated with a higher one-year mortality (Hazard Ratio 1.22, P <0.001 for binary troponin presence; Hazard Ratio 1.03, P <0.001 for each 0.01 ng/ml troponin increment). This relationship held for the subgroup of seven-day post-discharge survivors (Hazard Ratio 1.26, P <0.001). Minor elevations of troponin also significantly increased the net reclassification index over traditional risk markers for mortality prediction (net reclassification score 0.12, P <0.001). Minor troponin elevation was also associated with 30-day mortality (odds ratio 1.33, P=0.003). Importantly, troponin testing did not increase the adjusted mortality odds (P=0.9). Minor elevations in troponin substantially increase one-year, all-cause mortality in a stepwise fashion; it was also independently associated with 30-day mortality. We propose that minor elevations in troponin should not be regarded as clinically unimportant, but rather be included as a prognostic element if measured. We recommend prospective ICU studies to assess prognostic value of routine troponin determination.

Identification of weakly haemolytic Brachyspira isolates recovered from pigs with diarrhoea in Spain and Portugal and comparison with results from other countries

Weakly haemolytic anaerobic intestinal spirochaetes of the genus Brachyspira are commonly identified based on species-specific gene sequences. Apart from the pathogenic Brachyspira pilosicoli, the distribution and disease associations of the other weakly haemolytic Brachyspira species in pigs have not been comprehensively investigated. In this study weakly haemolytic Brachyspira isolates (n=67) from Spanish and Portuguese pigs with diarrhoea, negative in a routine diagnostic PCR for B. pilosicoli, were identified by sequencing their NADH oxidase genes (nox). Nearly half the isolates were identified as Brachyspira murdochii (n=31; 46.3%). The others were Brachyspira innocens (n=26; 38.8%), Brachyspira intermedia (n=7; 10.4%), "Brachyspira pulli" (n=1; 1.5%) and a potentially novel Brachyspira species (n=2; 3%). Multilocus sequence typing (MLST) on a subset of 18 isolates confirmed their species designations, including the potential new species, and identified similarities to strains from other countries.

Cardiovascular implantable electronic device implantation with uninterrupted dabigatran: comparison to uninterrupted warfarin

BACKGROUND

While continuation of oral anticoagulation (OAC) with warfarin may be preferable to interruption and bridging with heparin for patients undergoing cardiovascular implantable electronic device (CIED) implantation, it is uncertain whether the same strategy can be safely used with dabigatran.

OBJECTIVE AND METHODS

To determine the risk of bleeding and thromboembolic complications associated with uninterrupted OAC during CIED implantation, replacement, or revision, the outcomes of patients receiving uninterrupted dabigatran (D) were compared to those receiving warfarin (W).

RESULTS

D was administered the day of CIED implant in 48 patients (age 66 ± 12.4 years, 13 F and 35 M, 21 ICDs and 27 PMs), including new implant in 25 patients, replacement in 14 patients, and replacement plus lead revision in 9 patients. D was held the morning of the procedure in 14 patients (age 70 ± 11 years, 4 F and 10 M, 5 ICDs and 9 PMs). W was continued in 195 patients (age 60 ± 14.4 years, 54 F, and 141 M), including new implant in 122 patients, replacement in 33 patients, and replacement plus lead revision or upgrade in 40 patients. Bleeding complications occurred in 1 of 48 patients (2.1%) with uninterrupted dabigatran (a late pericardial effusion), 0 of 14 with interrupted D, and 9 of 195 patients (4.6%) on W (9 pocket hematomas), P = 0.69. Fifty percent of bleeding complications were associated with concomitant antiplatelet medications.

CONCLUSIONS

The incidence of bleeding complications is similar during CIED implantation with uninterrupted D or W. The risks are higher when OAC is combined with antiplatelet drugs.

Implications of left bundle branch block in patient treatment

Left bundle branch block (LBBB) causes an abnormal pattern of cardiac activation and affects regional myocardial function. Although recognition of LBBB on the surface electrocardiogram is straightforward, dissecting its effect on patient treatment and outcome can be more challenging. The altered pattern of cardiac activation in LBBB causes electrical and mechanical ventricular dyssynchrony, influences ischemia detection on the surface electrocardiogram, and affects stress testing and imaging modalities dependent on wall motion and thickening. Restoration of synchrony by biventricular pacing can improve symptoms and longevity in carefully selected patients. The diagnostic, prognostic, and therapeutic implications of LBBB across this spectrum are discussed in this review.

Effect of chest compressions on ventricular activation

External mechanical forces can cause ventricular capture and fibrillation (i.e., commotio cordis). In animals, we showed that chest compressions (CCs) can also cause the phenomenon. The aim of the present study was to determine whether ventricular capture by CCs occurs in humans. Electronic rhythm strips were analyzed in 31 cases of out-of-hospital cardiac arrest. The timing of the CCs was identified from the changes in thoracic impedance between the defibrillator pads. Ventricular capture was defined as QRS complexes of similar morphology occurring intermittently but synchronized with the CC artifact and impedance waveform. Only intermittent ventricular capture was identified to avoid misclassifying constant motion artifacts or intrinsic rhythm as ventricular capture. Of the 29 patients who received CCs for ≥1 minute, minimal or stable motion artifact was present in 24. Intermittent ventricular capture was found in 7 of the 24 patients. In the patients with ventricular capture, the number of ventricular activations (from ventricular capture and native beats) was greater during the CCs than when the CCs was not being performed (18 ± 8.9 vs 9.7 ± 4.0 activations in 15 seconds, p = 0.01). However, in patients without ventricular capture, they were similar (6.8 ± 8.2 vs 7.2 ± 8.8 activations in 15 seconds, p = 0.47). Refibrillation occurred in 22 patients; it began during the CCs in 16 and closely following their initiation in 3. In conclusion, CCs during cardiopulmonary resuscitation can electrically stimulate the heart. Additional studies evaluating the effect of ventricular capture on cardiopulmonary resuscitation outcomes, its relation to refibrillation, and methods to prevent or time ventricular capture by CCs are warranted.

Periods of highly synchronous, non-reentrant endocardial activation cycles occur during long-duration ventricular fibrillation

Periods of Highly Organized Activation During VF.

BACKGROUND

Little is known about long-duration ventricular fibrillation (LDVF), lasting 1-10 minutes when resuscitation is still possible.

METHODS AND RESULTS

To determine global left ventricle (LV) endocardial activation during LDVF, 6 canines (9.5 ± 0.8 kg) received a 64-electrode basket catheter in the LV, a right ventricular (RV) catheter, and a 12-lead electrocardiogram (ECG). Activation sequences of 15 successive cycles after initiation and after 1, 2, 3, 5, 7, and 10 minutes of LDVF were determined. Early during VF, LV endocardial activation was complex and present throughout most (78.0 ± 9.7%) of each cycle consistent with reentry. After 3-7 minutes of LDVF in 5 animals, endocardial activation became highly synchronized and present for only a small percentage of each cycle (18.2 ± 7.7%), indicating that LV endocardial reentry was no longer present. During this synchronization, activations arose focally in Purkinje fibers and spread as large wavefronts to excite the Purkinje system followed by the subendocardial working myocardium. During this synchronization, the ECG continued to appear irregular, consistent with VF, and LV cycle length (183 ± 29 ms) was significantly different than RV cycle length (144 ± 14 ms) and significantly different than the LV cycle length when synchronization was not present (130 ± 11 ms).

CONCLUSION

After 3-7 minutes of LDVF, a highly organized, synchronous, focal LV endocardial activation pattern frequently occurs that is not consistent with reentry but is consistent with triggered activity or abnormal automaticity in Purkinje fibers. The ECG continues to appear irregular during this period, partially because of differences in LV and RV cycle lengths.

Antimicrobial susceptibility testing of Spanish field isolates of Brachyspira hyodysenteriae

This study is the first conducted in Spain to evaluate antimicrobial susceptibility of field isolates of Brachyspira hyodysenteriae. One hundred and eight isolates of the bacterium, recovered from different Spanish swine farms between 2000 and 2007, were investigated. The minimum inhibitory concentrations (MIC) of erythromycin, tylosin, tiamulin, valnemulin, clindamycin and lincomycin were determined using a broth microdilution technique. Most of the isolates showed poor susceptibility to erythromycin (MIC(90)>256 microg/ml), tylosin (MIC(90)>256 microg/ml), clindamycin (MIC(90)>4 microg/ml) and lincomycin (MIC(90)=128 microg/ml). Reduced susceptibility to tiamulin and valnemulin was observed with a MIC>2 microg/ml in 17.6% and 7.41% of the B. hyodysenteriae isolates, respectively. Moreover, a survival analysis permitted the detection of an increasing trend in the MIC values for almost all the antimicrobials used in the treatment of swine dysentery when comparing recent isolates (from 2006 to 2007) with those recovered in earlier years (between 2000 and 2004).

Outcome of unresected gastric cancer after laparoscopic diagnosis of peritoneal carcinomatosis

BACKGROUND

Most gastric adenocarcinomas in western countries are locally advanced, and these tumours are often associated with metastatic spread at the time of diagnosis. It is controversial whether palliative surgery can improve symptom control in gastric cancer patients with peritoneal carcinomatosis.

OBJECTIVE

To determine the need of palliative procedures and survival in patients affected by gastric cancer with peritoneal carcinomatosis managed without resection. Methods and materials After standard preoperative staging, 160 patients were diagnosed with resectable gastric adenocarcinoma. Laparoscopy was performed in 107 patients (66.9%), finding peritoneal spread in 22 of them (21%). Seventeen of these patients were not submitted to any additional surgical procedure. Data regarding postoperative morbidity and mortality, need of endoscopic, percutaneous or surgical procedures to palliate symptoms, hospital stay and survival were collected. The same data were collected for the 6 non-resected patients who were diagnosed with carcinomatosis by laparotomy.

RESULTS

In the "laparoscopy alone" group, there were 2 minor complications and no postoperative mortality. Mean postoperative stay was 6 days. Eight patients had to be readmitted to hospital for symptoms derived from tumour progression, and 10 palliative endoscopic procedures were performed. Surgical interventions were not needed in any case. Mean survival was 11.5 months. Patients submitted only to laparotomy presented higher morbidity and mortality rates, with a longer postoperative stay and survival of less than 5 months.

CONCLUSIONS

Laparoscopic staging of gastric cancer can help to avoid unnecessary laparotomies. In patients with peritoneal carcinomatosis diagnosed by laparoscopy, nonsurgical treatment has low morbidity and mortality and permits good symptom relief with no shortening of survival.

In a swine model, chest compressions cause ventricular capture and, by means of a long-short sequence, ventricular fibrillation

BACKGROUND

During resuscitation, fibrillation often recurs. In swine, we studied refibrillation after long-duration ventricular fibrillation, investigating an association with chest compressions (CCs).

METHODS AND RESULTS

In protocol A, 47 episodes of long-duration ventricular fibrillation lasting at least 2.5 minutes were induced in 8 animals. After defibrillation, CCs were required for 35 episodes and delivered with a pneumatic device (Lucas cardiopulmonary resuscitation). In 9 episodes, refibrillation occurred within 2 seconds of CC initiation (group 1) and in 26 episodes, CCs were delivered without refibrillation (group 2). From the ECG and intracardiac electrodes, the RR interval preceding CCs, the shortest cycle length during the first 2 CCs (short), and the preceding cycle length (long) were measured. A similar study was conducted in 3 more animals without intracardiac catheters (protocol B). In protocol A, the mean RR before CC was 665+/-292 ms in group 1 and 769+/-316 in group 2. CCs stimulated ventricular beats in all 35 episodes. The short and long intervals were shorter in group 1 (215+/-31 and 552+/-210 ms) than in group 2 (402+/-153 and 699+/-147 ms) (P=0.009 and P=0.04, respectively). The prematurity index (short/RR) was lower in group 1 than in group 2 (0.35+/-0.09 vs 0.58+/-0.21; P<0.01). A short interval <231 ms predicted refibrillation with 88% sensitivity and 91% specificity. In protocol B, CCs were required in 11 episodes, causing ventricular stimulation in all of them and ventricular fibrillation within the first 2 CCs in 3.

CONCLUSIONS

Under some conditions, CC during resuscitation can stimulate the ventricles and initiate ventricular fibrillation by a long-short sequence.

Switching from twice-daily abacavir and lamivudine to the once-daily fixed-dose combination tablet of abacavir and lamivudine improves patient adherence and satisfaction with therapy

BACKGROUND

Patients prefer fewer pills and once-daily (qd) dosing without food restrictions. We assessed the impact on adherence [by Medication Event Monitoring System (MEMS) cap monitoring] of switching from abacavir (ABC) and lamivudine (3TC) twice daily (bid) to ABC/3TC fixed-dose formulation (FDC, Kivexa) qd to achieve a qd regimen.

METHODS

A randomized, open-label, 8-week study comparing adherence, efficacy and safety of immediate vs. delayed switching from ABC/3TC to FDC qd.

RESULTS

Ninety-four patients were dosed. Significantly improved adherence was observed at week 4 with qd ABC/3TC across all three adherence variables: taking compliance 99.2% (90.7-100%) vs. 96.6% (60.0-100%) (P=0.017); dosing compliance 97.1% (64.3-100%) vs. 91.9% (33.3-100%) (P=0.016); and timing compliance 95.5% (53.8-100%) vs. 86.3% (4.3-100%) (P=0.006). Treatment satisfaction increased significantly at week 4 with ABC/3TC qd [92% (82-99%) vs. 85% (75-93%) (P=0.004)]. Two patients were withdrawn from the study because of intolerance to ABC/3TC.

CONCLUSIONS

Switching from ABC and 3TC bid to ABC/3TC FDC qd significantly improved adherence by MEMS cap monitoring at week 4 and improved patient satisfaction with therapy. The results remain to be confirmed over a longer follow-up. Use of qd regimens supports adherence and improves treatment satisfaction relative to bid regimens.

[Anesthetic management during removal of a giant intrathoracic mass]

We report the case of a young woman with a giant intrathoracic angiomyolipoma accounting for 10% of her weight and occupying 75% of the right hemithorax and 30% of the left. Before anesthetic induction, an arterial line and a central venous catheter were applied for monitoring; neck and thoracic punctures were avoided. The trachea was intubated with a double lumen tube after provision of sedation and analgesia with remifentanil-midazolam and topical anesthesia of the larynx. A rigid bronchoscope and extracorporeal circulation were available at all times and muscle relaxants were avoided. Ventilation was maintained with pressure support until the mass effect was resolved. The patient was transferred to the intensive care unit, extubated after 24 hours, and discharged 5 days after surgery. We describe the recommendations for perioperative management in cases involving this type of tumor and the complications that can develop. Recent symptoms, diagnostic images, and the results of lung function tests provide information for guiding the anesthetic approach. The obstructive ventilatory compromise caused by a giant mass depends more on location than size. Extracorporeal circulation or rigid bronchoscopy might be needed at any time during surgery.

Better maintained adherence on switching from twice-daily to once-daily therapy for HIV: a 24-week randomized trial of treatment simplification using stavudine prolonged-release capsules

BACKGROUND

Adherence to antiretroviral therapy is critical to treatment outcomes. Adherence studies in other therapeutic areas of medicine suggest that once-daily regimens support improved adherence when compared to twice-daily therapy. An expansion in the range of once-daily antiretrovirals is making once-daily therapy possible for persons with HIV infection.

METHODS

A 24-week randomized open-label simplification study of twice-daily regimens based on stavudine immediate release or zidovudine to an all once-daily regimen based on the stavudine prolonged-release capsule (PRC), in persons with complete virological suppression on regimens also including efavirenz and lamivudine, was carried out. Subjects were assessed for adherence [using the Medication Event Monitoring System (MEMS) cap; Aardex Corporation, Union City, CA, USA], quality of life, tolerability and efficacy.

RESULTS

Forty-three patients were randomly assigned: 21 remained on their original regimen and 22 switched to once-daily therapy with stavudine PRC. Although high levels of adherence and good quality of life were present at study enrollment, adherence declined to a significantly lesser extent at week 24 in the group that switched to once-daily therapy. Efficacy was maintained in both groups and there were no differences in tolerability or toxicity.

CONCLUSIONS

Subjects switching from twice-daily therapy to once-daily therapy demonstrate less of a decline in adherence over 24 weeks. A once-daily regimen including stavudine PRC is as effective and tolerable as a regimen containing the twice-daily formulation.

A family based study shows no association between rheumatoid arthritis and the PADI4 gene in a white French population

BACKGROUND

Autoantibodies to citrullinated proteins (ACPA) are considered a specific marker for rheumatoid arthritis. Peptidylarginine deiminase (PAD) is the enzyme that converts arginyl into citrullyl residues; different isoforms of the enzyme are expressed in mammals. It has been suggested that the PADI4 gene may contribute to genetic susceptibility to rheumatoid arthritis, but conflicting results have been obtained in different populations.

OBJECTIVE

To test the hypothesis that the PADI4 gene may confer susceptibility to rheumatoid arthritis in a white French population, using powerful and highly reliable family based association tests.

METHODS

DNA samples were analysed from 100 families where one member was affected by rheumatoid arthritis and both parents were available for sampling. Five single nucleotide polymorphisms, located within the PADI4 gene and in its close proximity, were genotyped by restriction fragment length polymorphism, and haplotypes were constructed. The analysis involved use of the transmission disequilibrium test and genotype relative risk. ACPA were detected by ELISA on cyclic citrullinated peptides and on human deiminated fibrinogen.

RESULTS

No single SNP or haplotype was associated with the disease, or was preferentially transmitted. No association was found when patients were partitioned according to ACPA positivity.

CONCLUSIONS

No PADI4 haplotype is associated with rheumatoid arthritis in a white French population. The role of genes encoding the other PAD isoforms, or modulating tissue expression or enzyme activity, remains to be elucidated.