Cardiorespiratory events in infants with gastroesophageal reflux symptoms: Is there any association?

BACKGROUND: Cardiorespiratory (CR) events (apnea, bradycardia, oxygen desaturation) and gastroesophageal reflux (GER) symptoms often coexist in infants admitted to Neonatal Intensive Care Unit, leading to over-prescription of drugs and delayed discharge. We aimed to evaluate the relationships between CR and GER events. METHODS: The temporal associations between CR and GER events were analyzed in symptomatic infants who underwent synchronized CR and pH-impedance monitoring. The symptom association probability (SAP) index was used to identify infants with a significant number of temporal associations. Gastroesophageal reflux characteristics and the chronological sequence of CR and GER events occurring within 30 seconds of each other were evaluated according to SAP index. KEY RESULTS: Of the 66 infants enrolled, aged 29 (18-45) days, 58 had CR events during monitoring. From these 58 patients, a total of 1331 CR events and 5239 GER (24% acidic) were detected. The SAP index was positive in seven (12%) infants. These infants had greater GER frequency, duration, and proximal extent (P < .05). The number of temporal associations was 10 times greater in the positive SAP group. Gastroesophageal reflux events preceded CR events in 83% of these associations. These GER events had a higher proximal extent (P = .004), but showed no differences in pH values. CONCLUSIONS & INFERENCES: The simultaneous evaluation of CR and GER events could be useful to identify infants with severe GER and significant temporal associations between these events. Treatment of GER could be indicated in these infants, but as the GER events involved are mainly non-acidic, empirical treatment with antacids is, often, inappropriate.

Surveillance Registry of Sirolimus Use in Recipients of Kidney Allografts From Expanded Criteria Donors.

BACKGROUND: The use of expanded criteria donor (ECD) kidneys has increased the overall availability of renal transplants. This study assessed the use of sirolimus in patients receiving Argentina-ECD kidneys. METHODS: This observational, open-label, 1-arm, prospective, longitudinal pilot study was conducted at 8 transplant centers in Argentina. Adults receiving kidney transplants (without pancreas) from ECDs were eligible if they were converted to sirolimus 1 to 36 months' posttransplantation, with sirolimus becoming base therapy within 1 month after conversion. Patients were followed up for 1 year. Outcomes included reasons for conversion, acute rejection, patient and graft survival, graft status, and safety. RESULTS: The intention-to-treat population included 52 patients (mean age, 48.7 years). Calcineurin inhibitor nephropathy (40%) and chronic allograft nephropathy (25%) were the most frequent reasons for conversion. Two acute rejections occurred during follow-up, but no patients experienced graft loss. One patient died during follow-up, and 3 patients died within 1 month of the last sirolimus dose. Levels of serum creatinine and creatinine clearance remained stable from baseline to week 52/53. Mean proteinuria measured in a subset of patients was 0.2 ± 0.2 g/24 hours before conversion and increased to 0.6 ± 1.2 g/24 hours at week 24/25 and 0.5 ± 0.6 g/24 hours at week 52/53. Adverse events were consistent with those in previous conversion trials; the most common were infections and infestations (54%). CONCLUSIONS: This pilot study illustrates the potential benefits of sirolimus in recipients of ECD kidneys in Argentina. Larger, randomized controlled trials are needed to confirm these findings and to clarify the long-term benefits of sirolimus in this patient population.

First epidemiologic study in Argentina of the prevalence of BK viruria in kidney transplant patients.

BACKGROUND: The worldwide seroprevalence of human BK polyomavirus (BKV) in adults is 80%. About 10%-60% of renal transplant recipients experience BKV infection, nephropathy of the graft may occur in 5% of the cases, and up to 45% lose the graft. The aim of this work was to describe the prevalence of BK viruria during the 1st year after transplantation. METHODS: An epidemiologic multicenter cross-sectional study was carried out in consecutive patients at each site with kidney transplantation from August 2011 to July 2012. Clinically significant viruria was defined as >10(7) copies/mL. Viral DNA was extracted with the use of silica columns. Quantification was performed with the use of real-time polymerase chain reaction with primers that amplify a fragment of the large T-antigen gene and with a specific Taqman-MGB probe for BKV. For each assay, a standard curve with a quantified plasmid was included. RESULTS: Of 402 renal transplant recipients at 18 renal transplant sites, we analyzed 382; median age was 46.33 years, and 46.40% were female. The median of the temporal distribution for urine samples was 153 days. BK virus was detected in 50/382 samples (13%), 18 with values >10(7) copies/mL (4.7%). The median of the distribution of positive values was 123 days and the highest frequency of positive values was in months 3-7. The conditions of recipient older than 34 years and donor older than 41 years were the only ones that showed statistically significant association with BK viruria. No association with any specific immunosuppressive drug was observed. CONCLUSIONS: This is the first multicenter study conducted in Argentina to determine the prevalence of BK viruria in renal transplant recipients. Because of the growing number of the population susceptible to this infection, it is important to register and describe data about its epidemiology and associated risk factors.

Relationship between sleep/wakefulness and gastroesophageal reflux in symptomatic newborns.

The state of sleep/wakefulness is well known to influence esophageal acid exposure and the number of acid refluxes whereas it is uncertain whether the same is true of the non-acid refluxes that predominate in the newborns. To investigate the relationship between sleep/wakefulness and refluxes 45 newborns with gastroesophageal reflux symptoms were studied with combined multichannel intraluminal impedance and pH monitoring. We found that sleep/wakefulness influenced acid and weakly acidic reflux frequency (awake 2.6+/-0.8; asleep 2.1+/-1.1; p=0.006). A negative correlation was found between sleepness periods and the mean reflux duration for both acid (R=0.55;p < 0.001) and weackly acidic (R=0.51;p < 0.001) refluxes. This finding may raise some concerns about the over-prescription of antacid drugs in newborns.

Enhanced glomerulopressin production and glomerular filtration rate by amino acid infusion in normal humans.

Amino acid infusion induces a rise in glomerular filtration rate (GFR) in normal subjects, but the mechanism is as yet unknown. Glomerulopressin infused into the renal arteries of rats and dogs increases GFR. The aim of this study was to ascertain whether amino acid infusion raised glomerulopressin production and GFR. Accordingly, before renal arteriovenography, in 11 potential kidney donors, the caval catheter was introduced into the right hepatic vein and 60-ml blood samples were collected at the beginning and end of each experiment; six patients received amino acid infusion and five a saline infusion. Glomerulopressin in ultrafiltrates from hepatic vein plasma was measured by toad bioassay and GFR determined with diethylenetriamine pentaacetic acid-Tc99. The amino acid-infused group showed significant glomerulopressin activity in ultrafiltrates, as well as a significant GFR increase, whereas in the control group no glomerulopressin activity was observed, and there was no change in GFR. These findings suggest that intravenous amino acid infusion stimulates glomerulopressin production, which may in turn induce an increase in GFR.