Comparison of superstimulatory protocols with different doses of eCG on ovarian response and oocyte recovery by follicular aspiration in llamas (Lama glama).

The objective of this study was to evaluate the effect of three doses of equine chorionic gonadotropin (eCG) for ovarian superstimulation on ovarian response, follicular development and cumulus-oocyte complexes (COCs) collection in llamas. For this purpose, eighteen multiparous non-lactating adult (4-7 yo) female llamas with an average body condition of 2.8 (BCS 1-5) were submitted to a follicular ablation (FA) to induce a new follicular wave emergence. Two days after FA (Day 0), synchronized llamas were randomly allocated to three treatment groups (n = 6/group) and given 500, 750 and 1000 IU of eCG (Novormon®, Syntex, Buenos Aires, Argentina) per animal respectively to induce ovarian superstimulation. Transrectal ultrasonography were performed on Days 2, 4, and 6; and ovum pick up (OPU) was performed on Day 6. Data was evaluated by one-way analysis of variance (ANOVA), repeated measures ANOVA, and 2-tailed Chi-square. The average size (mm) of follicles was greater (p≤ 0.05) in the 1000 IU group compared to the other groups. There was a greater (p≤ 0.05) number of follicles ≥ 7 mm in the 1000 IU group compared to the 500 IU group. Number of COCs collected on Day 6 and the COC recovery rate were not different among groups. In conclusion, a single dose of 1000 IU of eCG induced the best ovarian response resulting in larger and greater number of follicles at the time of OPU.

Cooling of alpaca spermatozoa using an extender with the addition of different percentages of seminal plasma.

The objective of this study was to evaluate the effect of the addition of different percentages of seminal plasma (SP) during the cooling at 5 °C of alpaca spermatozoa from vas deferens. Fifteen pools of sperm from vas deferens were evaluated and then divided into four aliquots that were diluted to a final concentration of 30 × 106 sperm/ml with either: (1) Tris with 20% egg yolk (T-EY) (control, 0% SP), (2) T-EY with 10% SP, (3) T-EY with 25% SP, and (4) T-EY with 50% SP. Samples were cooled at 5 °C and the following sperm parameters were evaluated after 24 and 48 h of storage: motility, viability, membrane function, acrosome integrity, morphology, and chromatin condensation. Motility was also evaluated after 72 h of storage. A significant decrease in progressive and total sperm motility was observed in samples cooled with 50% SP with respect to all diluted samples, while these parameters were preserved in samples cooled with 0%, 10%, and 25% SP. The percentages of sperm viability, normal morphology, and highly condensed chromatin did not change after the cooling process and were similar between cooled samples. Although a significant decrease was observed in the percentage of spermatozoa with functional membranes and with an intact acrosome in all refrigerated samples compared to raw sperm, the greatest decrease was observed in samples cooled with 50% SP. No advantage was observed from the addition of SP to alpaca spermatozoa obtained from vas deferens and being cooled. In addition, to preserve the sperm motility of cooled samples for up to 72 h, it should be recommended to include a 10% SP in the extender.

Seasonal autoregressive integrated moving average (SARIMA) time-series model for milk production forecasting in pasture-based dairy cows in the Andean highlands.

Milk production in the Andean highlands is variable over space and time. This variability is related to fluctuating environmental factors such as rainfall season which directly influence the availability of livestock feeding resources. The main aim of this study was to develop a time-series model to forecast milk production in a mountainous geographical area by analysing the dynamics of milk records thorough the year. The study was carried out in the Andean highlands, using time-series models of monthly milk records collected routinely from dairy cows maintained in a controlled experimental farm over a 9-year period (2008-2016). Several statistical forecasting models were compared. The Mean Absolute Error (MAE), Root Mean Square Error (RMSE), and Mean Absolute Percent Error (MAPE) were used as selection criteria to compare models. A relation between monthly milk records and the season of the year was modelled using seasonal autoregressive integrated moving average (SARIMA) methods to explore temporal redundancy (trends and periodicity). According to white noise residual test (Q = 13.951 and p = 0.052), Akaike Information Criterion and MAE, MAPE, and RMSE values, the SARIMA (1, 0, 0) x (2, 0, 0)12 time-series model resulted slightly better forecasting model compared to others. In conclusion, time-series models were promising, simple and useful tools for producing reasonably reliable forecasts of milk production thorough the year in the Andean highlands. The forecasting potential of the different models were similar and they could be used indistinctly to forecast the milk production seasonal fluctuations. However, the SARIMA model performed the best good predictive capacity minimizing the prediction interval error. Thus, a useful effective strategy has been developed by using time-series models to monitor milk production and alleviate production drops due to seasonal factors in the Andean highlands.

Aortic valve reconstruction surgery with Ozaki technique: initials results from a single center / Cirugía de reconstrucción de válvula aórtica con técnica de Ozaki: resultados iniciales en un centro de referencia

Abstract Background: Aortic valve (AV) replacement is the gold standard treatment for severe symptomatic AV disease. Recently, AV reconstruction surgery (Ozaki procedure) emerges as a surgical alternative with good results in the medium term. Methods: We retrospectively analyzed 37 patients who underwent AV reconstruction surgery between January 2018 and June 2020 in a national reference center in Lima, Peru. The median age was 62 years, interquartile range (IQR: 42-68). The main indication for surgery was AV stenosis (62.2%), in most cases due to bicuspid valve (19 patients, 51.4%). Twenty-two (59.4%) patients had another pathology with surgical indication associated to AV disease, 8 (21.6%) had dilatation of the ascending aorta with indication for replacement. Results: One in-hospital death occurred (1/38, 2.7%) due to perioperative myocardial infarction. There was a significant reduction in the medians of the peak (70 mmHg, CI 95% = 50.03-79.86 vs. 14 mmHg, CI 95% = 11.93-17.5, p < 0.0001) and mean (45.5 mmHg CI 95% = 30.6-49.68 vs. 7 mmHg, CI 95% = 5.93-9.6, p < 0.0001) AV gradients when we compared baseline characteristics with first 30-days results. In an average of 19 (± 8.9) months of follow-up, survival, reoperation-free survival for valve dysfunction, and survival free of AV insufficiency ≥ II were 97.3%, 100% and 91.9%, respectively. Significant reduction in the medians of the peak and mean AV gradients was maintained. Conclusions: AV reconstruction surgery showed optimal results in term of mortality, reoperation-free survival, and hemodynamic characteristics of the neo-AV.

Resumen Introducción: El reemplazo de la válvula aórtica es el tratamiento de elección para la valvulopatía aórtica severa sintomática. Recientemente, la cirugía de reconstrucción valvular aórtica (procedimiento de Ozaki) emerge como una alternativa quirúrgica con buenos resultados a mediano plazo. Métodos: Analizamos retrospectivamente 37 pacientes intervenidos de reconstrucción de válvula aórtica entre enero de 2018 y junio de 2020 en un centro de referencia nacional en Lima, Perú. La mediana de edad fue de 62 años (rango intercuartílico: 42-68). La estenosis de la válvula fue la principal indicación de cirugía (62.2%), en la mayoría de los casos por válvula bicúspide (19 pacientes, 51.4%). 22 (59.4%) pacientes presentaban otra patología con indicación de cirugía, 8 (21.6%) presentaban dilatación de la aorta ascendente con indicación de reemplazo. Resultados: La mortalidad intrahospitalaria fue de 1/38, 2.7%, por infarto de miocardio perioperatorio. Hubo una reducción significativa en las medianas del gradiente máximo (70 mmHg, IC 95% = 50.03-79.86 vs. 14 mmHg, IC 95% = 11.93-17.5, p < 0.0001) y gradiente medio (45.5 mmHg IC 95% = 30.6-49.68 vs. 7 mmHg, IC 95% = 5.93-9.6, p < 0.0001) de la válvula aórtica cuando comparamos las características basales con los resultados de los primeros 30 días. En una media de 19 (± 8.9) meses de seguimiento la sobrevida fue del 97.3%; la sobrevida libre de reoperación por disfunción valvular, 100% y la sobrevida libre de insuficiencia aórtica ≥ II, 91.9%, respectivamente. Se mantuvo una reducción significativa en las medianas de los gradientes máximo y medio de la válvula aórtica. Conclusiones: La cirugía de reconstrucción de válvula aórtica con pericardio autólogo mostró resultados óptimos en términos de mortalidad, supervivencia libre de reoperación y características hemodinámicas de la neo-válvula.

Effect of assessing velocity time integral at different locations across ventricular outflow tracts when calculating cardiac output in neonates.

This study aims to evaluate the effect of assessing velocity time integral at different locations across ventricular outflow tracts for calculating cardiac output (CO) in neonates. Velocity time integral (VTI) and CO were measured at 3 different locations across right and left ventricular outflow tracts using transthoracic echocardiography in healthy term neonates without any major congenital heart disease. ANOVA with Bonferroni correction was used to determine the differences between the VTI and CO sampled at these three locations. Forty-one neonates met inclusion criteria with mean gestational age of 38.6 ± 1 weeks and mean birth weight of 3155 ± 463 g. The median hours after birth when echocardiography was obtained was 23 h (range 11-68 h after birth). Left CO were 121 ± 30 mL/kg/min, 155 ± 38 mL/kg/min, and 176 ± 36 mL/kg/min measured below the valve, hinges of the valve, and tip of the valve, respectively. Right CO were 197 ± 73 mL/kg/min, 270 ± 83 mL/kg/min, and 329 ± 104 mL/kg/min measured below the valve, hinges of the valve, and tip of the valve, respectively. A statistically significant difference (P < 0.001) was found in the VTI and CO measured at the 3 different locations across both left and right ventricular outflow tracts.     Conclusions: There is a significant difference in measurements of VTI and CO depending on the location of Doppler gate sampling across the ventricular outflow tracts. Consistency and precision in Doppler gate location are essential for measuring VTI and calculating CO while assessing changes in hemodynamic status in critically ill infants. What is Known: • Targeted Neonatal Echocardiography is increasingly applied to measure cardiac output in critically ill neonates and serial assessments are performed to assess the trend in changes in cardiac output. • Noninvasive measurement using velocity time integral to calculate cardiac output is commonly performed. However, location of Doppler sample gate to measure ventricular outflow tract velocity time integral is not consistent. What is New: • Statistically significant changes in measured velocity time integral and cardiac output are noted based on the location of Doppler gate sampling. • To monitor the cardiac output for trending, it is important to be consistent with regards to the location of the Doppler sample gate to assess changes in cardiac output in critically ill newborns.

Age-Related Differences in Testosterone Concentration and Its Relation to Testicular Biometrics, Hemodynamics, and Fertility in Alpacas (Vicugna pacos).

The goal of this study was to investigate the age-related differences in testosterone concentration and its relation to testicular biometrics, testicular blood flow, and fertility in alpacas (Vicugna pacos). Fifteen alpaca males with different ages (young (YM; ~12-14 mo.), n = 5; intermediate (IM; ~24 mo.), n = 5; and old (OM; ≥36 mo.), n = 5) were enrolled in the study. Blood samples were taken from each alpaca male and the circulating plasmatic testosterone concentration (TC; ng/mL) was determined using ELISA analysis. The testicular traits related to bio-morphometric parameters (the length (L), width (W), area (A), and volume (TV)) were assessed using B-mode ultrasonography. Pulse-wave/power Doppler ultrasonography was used to obtain the circulatory dynamic values (testicular hemodynamics) before the beginning of natural service mating. Significant differences were observed in TC among the age groups, increasing as the age of the males increased (2.47 ± 0.31, 8.45 ± 1.53, and 22.66 ± 2.15 for YM, IM, and OM, respectively; p < 0.05); however, no differences were observed regarding the testicular B-mode ultrasonographic parameters (L, W, and A) (p > 0.05). Positive correlations were observed between TV and testicular L, W, and A (r = 0.96, r = 0.95, and r = 0.96, respectively; p ≤ 0.001). Pulse-wave-Doppler-derived parameters such as the pulsatility index (PI) and the resistive index (RI), as well as the total vascularity area (TVA) assessed by power Doppler, were similar in all of the age groups studied (p > 0.05). General linear model (GLM) analysis showed a relationship between TC and TV (OR = 0.95; p = 0.04), as well as between TC and TVA (OR = 0.99; p= 0.02). Finally, no differences were observed regarding the pregnancy rate among the different age groups (p > 0.05). In conclusion, TC increased as the age of the alpaca males increased. Although TC was related to TV and TVA, the pregnancy rates obtained from individuals belonging to the different age groups were similar, indicating that TC, TV, and TVA were not determining factors in assessing the potential age-related fertility differences in alpaca males.

Phenotypic Characterization of Creole Cattle in the Andean Highlands Using Bio-Morphometric Measures and Zoometric Indices.

Several Creole cattle biotypes can be found in the Andean highlands, and most of them are considered as being in risk of extinction. The main aim of the present study was to perform a phenotypic characterization of the Creole cattle in the Andean highlands using bio-morphometric measures and zoometric indices. Individuals from three different biotypes (Black 'Negro' (n = 57), Colour-Sided 'Callejón' (n = 20), and Brindle 'Atigrado' (n = 18)) from an experimental research center located in the Peruvian highlands were enrolled in the study. In total, seventeen morphometric parameters were evaluated and ten zoometric indices were calculated in each biotype. To test the relationship between biometric traits, correlation analyses were carried out between morphometric parameters. Differences were observed regarding different morphometric variables such as head length (HL) and rump length (RL) among cattle biotypes (p ≤ 0.05). The coefficient of variation (CV; %) regarding different morphometric parameters ranged between 11.32 for neck length (NL) and 3.63 for height at withers (HaW), which indicated low-moderate variability among morphometric variables. Differences were observed in the longitudinal pelvic index (LPI) when different zoometric indices were compared among biotypes (p ≤ 0.05). The CV regarding different zoometric indices, which ranged between 10.78 for the cephalic index (CEI) and 5.05 for LPI, indicated low variability among indices. No differences were observed in any other morphometric parameter or zoometric index among cattle biotypes or genders (p > 0.05). Finally, multiple correlations were observed between morphometric variables (p ≤ 0.05). In conclusion, it was determined that Peruvian Andean Creole cattle can be considered as a dairy-related biotype with a slight tendency for beef production (dual-purpose). The great homogeneity regarding zoometric characteristics among biotypes and genders may indicate that the Andean Creole cattle have been maintained quite isolated, avoiding the genetic influence of other foreign breeds. Finally, the phenotypic characterization including bio-morphometric measurements and zoometric indices obtained from the different Creole bovine biotypes is crucial in order to begin different conservation programs to preserve cattle breeds in the Peruvian Andean highlands.

Twin Premature Infants With Riboflavin and Biotin Deficiency Presenting With Refractory Lactic Acidosis, Rash, and Multiorgan Failure During Prolonged Parenteral Nutrition.

We are reporting monochorionic, diamniotic twin premature infants born at 25 weeks and 6 days gestation with riboflavin (vitamin B2) and biotin (vitamin B7) deficiency, while on prolonged total parenteral nutrition (TPN) during vitamin shortage. They presented initially with skin rash, lactic acidosis, and thrombocytopenia. Both twins progressed to severe respiratory failure, severe lactic acidosis, with refractory vasodilatory shock, pancytopenia, ischemic bowel injury, acute kidney injury, liver injury, and capillary leak syndrome leading to death of twin A. The surviving twin B was diagnosed with riboflavin and biotin deficiency that presented with abnormal metabolic work up suggestive of maple syrup urine disease, glutaric acidemia type 2, and X-linked adrenoleukodystrophy. Twin B was started on riboflavin and biotin supplementation at 41 days of life, with rapid improvement in clinical findings and laboratory abnormalities within days of starting biotin and riboflavin supplementation. He was discharged home in stable condition at 49 weeks of postmenstrual age.

[Aortic valve reconstruction surgery with Ozaki technique: initials results from a single center]. / Cirugía de reconstrucción de válvula aórtica con técnica de Ozaki: resultados iniciales en un centro de referencia.

Background: Aortic valve (AV) replacement is the gold standard treatment for severe symptomatic AV disease. Recently, AV reconstruction surgery (Ozaki procedure) emerges as a surgical alternative with good results in the medium term. Methods: We retrospectively analyzed 37 patients who underwent AV reconstruction surgery between January 2018 and June 2020 in a national reference center in Lima, Peru. The median age was 62 years, interquartile range (IQR: 42-68). The main indication for surgery was AV stenosis (62.2%), in most cases due to bicuspid valve (19 patients, 51.4%). Twenty-two (59.4%) patients had another pathology with surgical indication associated to AV disease, 8 (21.6%) had dilatation of the ascending aorta with indication for replacement. Results: One in-hospital death occurred (1/38, 2.7%) due to perioperative myocardial infarction. There was a significant reduction in the medians of the peak (70 mmHg, CI 95% = 50.03-79.86 vs. 14 mmHg, CI 95% = 11.93-17.5, p < 0.0001) and mean (45.5 mmHg CI 95% = 30.6-49.68 vs. 7 mmHg, CI 95% = 5.93-9.6, p < 0.0001) AV gradients when we compared baseline characteristics with first 30-days results. In an average of 19 (± 8.9) months of follow-up, survival, reoperation-free survival for valve dysfunction, and survival free of AV insufficiency ≥ II were 97.3%, 100% and 91.9%, respectively. Significant reduction in the medians of the peak and mean AV gradients was maintained. Conclusions: AV reconstruction surgery showed optimal results in term of mortality, reoperation-free survival, and hemodynamic characteristics of the neo-AV.

Introducción: El reemplazo de la válvula aórtica es el tratamiento de elección para la valvulopatía aórtica severa sintomática. Recientemente, la cirugía de reconstrucción valvular aórtica (procedimiento de Ozaki) emerge como una alternativa quirúrgica con buenos resultados a mediano plazo. Métodos: Analizamos retrospectivamente 37 pacientes intervenidos de reconstrucción de válvula aórtica entre enero de 2018 y junio de 2020 en un centro de referencia nacional en Lima, Perú. La mediana de edad fue de 62 años (rango intercuartílico: 42-68). La estenosis de la válvula fue la principal indicación de cirugía (62.2%), en la mayoría de los casos por válvula bicúspide (19 pacientes, 51.4%). 22 (59.4%) pacientes presentaban otra patología con indicación de cirugía, 8 (21.6%) presentaban dilatación de la aorta ascendente con indicación de reemplazo. Resultados: La mortalidad intrahospitalaria fue de 1/38, 2.7%, por infarto de miocardio perioperatorio. Hubo una reducción significativa en las medianas del gradiente máximo (70 mmHg, IC 95% = 50.03-79.86 vs. 14 mmHg, IC 95% = 11.93-17.5, p < 0.0001) y gradiente medio (45.5 mmHg IC 95% = 30.6-49.68 vs. 7 mmHg, IC 95% = 5.93-9.6, p < 0.0001) de la válvula aórtica cuando comparamos las características basales con los resultados de los primeros 30 días. En una media de 19 (± 8.9) meses de seguimiento la sobrevida fue del 97.3%; la sobrevida libre de reoperación por disfunción valvular, 100% y la sobrevida libre de insuficiencia aórtica ≥ II, 91.9%, respectivamente. Se mantuvo una reducción significativa en las medianas de los gradientes máximo y medio de la válvula aórtica. Conclusiones: La cirugía de reconstrucción de válvula aórtica con pericardio autólogo mostró resultados óptimos en términos de mortalidad, supervivencia libre de reoperación y características hemodinámicas de la neo-válvula.

Pulmonary Valve Reconstruction Using Autologous Pericardium: A Promising Technique to Consider.

Pulmonary valve (PV) surgical treatment is uncommon in adults; however, when it is indicated, replacement with a prosthesis is suggested. Nevertheless, mechanical prostheses have an inherent risk of complications derived from anticoagulation and thrombosis, and biologic prostheses do not have adequate long-term durability. In this context, PV reconstruction surgery emerges as an alternative, avoiding anticoagulation and promising good durability. We present our experience with this procedure in 3 patients with severe PV insufficiency and 1 patient with severe PV stenosis.

Ovarian Follicular Dynamics and Its Functional Significance in Relation with Follicle Deviation, Vaginal Cytology, and Hormone Profiles in Llamas (Lama glama).

The reproductive physiology in camelid species has its particularities. The present study aimed to characterize the ovarian follicular dynamics and its functional significance in relation to follicular deviation, vaginal cytological characteristics, and sexual hormone profiles in llamas as the first report in South American camelids. Non-pregnant, multiparous llamas (Lama glama; n = 10; age: 48−72 mo.; BCS: 2.5−3.0) were enrolled in the study. The ultrasonographic assessment was carried out transvaginally and follicular ablation was performed (day 0) when follicles were larger than 7 mm. The follicle number and diameter were scored daily throughout the process for a proper evaluation of the deviated follicles and to monitor the presence of new follicle pools (1.5 to 2.5 mm diameter). Vaginal cytological evaluation (parabasal, intermediate, and superficial cells) was performed every other day until day 6. Endocrine profiles (17ß estradiol, anti-Mullerian hormone, testosterone, and progesterone) during pre- and post-follicular deviation were determined by using the ELISA assay. Differential follicular dynamics both in the presence of a single dominant follicle (DF) and in codominance during the follicular deviation process were detected in llamas (p < 0.05). The percentage of superficial cells was the most related to the follicular wave phase. However, the percentage of parabasal, intermediate, and superficial cells was not related to the phases of follicular growth, dominance, and regression (p > 0.05). Differential patterns among the different hormone concentration levels regarding the 17ß estradiol, anti-Mullerian hormone, progesterone, and testosterone during follicular deviation were observed, with the latter being significantly different along the deviation process (p < 0.05). In conclusion, the use of vaginal cytology assessment would not be sufficient to determine the follicular phases in llamas. Therefore, complementary analyses, such as ultrasonography and endocrine assessment, are strongly recommended to determine follicular dynamics during the follicular deviation.

Spermatozoa Obtained From Alpaca vas deferens. Effects of Seminal Plasma Added at Post-thawing.

The viscous seminal plasma (SP) is currently a major impediment to the handling of ejaculate and the development of some biotechnologies in South American camelids. The vas deferens-collected spermatozoa of alpacas is a useful technique to avoid this problem. On the other hand, SP contains a large protein component that has been implicated in the function of spermatozoa within the female reproductive tract. In this sense, the low fertility achieved using transcervical insemination with frozen-thawed spermatozoa in alpacas could be improved by adding SP. This study aimed to evaluate the effect of the whole SP on some in vitro parameters of alpaca spermatozoa after the freezing-thawing-process and the fertility after artificial insemination. It would contribute to a better understanding of the interaction between thawed sperm cells and SP. Spermatozoa were obtained by surgically diverted vas deferens. The samples were diluted with a Tris-based extender, packaged in straws, and frozen. At thawing, each straw was divided into two post-thawing conditions: with the addition of 10% of PBS (control) or with 10% SP (treatment). The sperm cells were evaluated using dynamic parameters, sperm cell morphology, and morphometry. Fertility was assessed by an artificial insemination trial. All in vitro parameters were analyzed by ANOVA. A heterogeneity test was scheduled for the fertility trial. After the freezing-thawing process, motility and plasma membrane functionality was improved when SP was added. No differences were found for post-thaw viability between the control and treatment samples. The percentage of normal cells was higher with SP at post-thawing, and a decrease of the presence of bent tailed spermatozoa with a droplet in the SP group was observed. The length of the head spermatozoa was 3.4% higher in the samples with PBS compared to those in which SP was added. Females pregnant at day 25 post-insemination were 0/12 (with SP inside the straw) and 1/10 (without SP inside the straw). In conclusion, the presence of 10% SP at post-thawing improves sperm cells' motility, functionality, and morphology, indicating that it would be beneficial to improve the frozen-thawed alpaca's physiology spermatozoa. More fertility trials must be developed to increase this knowledge.

Pulmonary function in extremely low birth weight infants with bronchopulmonary dysplasia before hospital discharge.

OBJECTIVE: To compare pulmonary function in extremely low birth weight (ELBW) infants with bronchopulmonary dysplasia (BPD) studied at 34-36 weeks postmenstrual age (PMA) with a reference group of "healthy" infants born at 34-36 weeks. We hypothesized that ELBW infants have decreased functional residual capacity (FRC) and respiratory compliance (Crs). STUDY DESIGN: Pulmonary function testing was performed at 34-36 weeks PMA in infants with BPD and within 96 h of age in infants delivered at 34-36 weeks. RESULTS: Twenty BPD patients and 20 healthy infants were studied. FRC (18.9 versus 26.2 mL/kg; adjusted 95% CI 5.0, 10.9; P < 0.001) and Crs (0.80 versus 1.29-mL/cm H2O/kg; 95% CI 0.31, 0.71; P < 0.001) were decreased in BPD patients. Respiratory resistance was increased in BPD patients. CONCLUSIONS: ELBW infants with BPD have decreased pulmonary function compared to healthy infants delivered at 34-36 weeks. This suggests that infants with BPD have smaller lung volumes.

Respiratory Compliance in Late Preterm Infants (340/7-346/7 Weeks) after Antenatal Steroid Therapy.

OBJECTIVE: To compare respiratory compliance in late preterm infants (340/7-346/7 weeks) who received antenatal steroids vs matched late preterm infants who did not receive antenatal steroids. STUDY DESIGN: This was a single-center prospective cohort study. Patients were matched for birth weight, gestational age, race, and sex. Respiratory compliance was the primary outcome measured with the single breath occlusion technique. RESULTS: We studied 25 late preterm infants treated with antenatal steroids and 25 matched infants who did not receive antenatal steroids. The treated infants had a significantly increased respiratory compliance/kg (adjusted 95% CI 0.05, 0.49; P = .016) and fewer required continuous positive airway pressure (P = .007) or >24 hours of supplemental oxygen (P = .046). There was no difference in surfactant therapy. CONCLUSIONS: Respiratory compliance was significantly increased in this cohort of late preterm infants born at 340/7-346/7 weeks who received antenatal steroids compared with matched infants who did not receive antenatal steroids. Although not randomized, these data provide physiologic support for the possible beneficial effects of antenatal steroids in late preterm infants.

Pulmonary function and outcomes in infants randomized to a rescue course of antenatal steroids.

BACKGROUND/OBJECTIVE: Our objective was to obtain follow-up pulmonary function testing and assessment of clinical respiratory outcomes, at 1-2 years, in preterm infants whose mothers were randomized to a single rescue course of antenatal steroids (AS) versus placebo. METHODS: Follow-up of a randomized, double-blinded trial. In the original trial pregnant women ≥14 days after initial course of AS were randomized to rescue AS or placebo. Pulmonary function testing and a standardized respiratory questionnaire were obtained at 1-2 years of corrected age. Respiratory compliance (Crs) was measured with the single-breath occlusion and functional residual capacity (FRC) with the nitrogen washout method. Analysis was by intention-to-treat. RESULTS: A total of 96 (87%) of available survivors were administered a respiratory questionnaire. Seventy-seven percent of available patients had pulmonary function testing performed. There was no significant difference between groups in incidence of wheezing, asthma, respiratory syncytial virus infection, respiratory readmissions, use of bronchodilators or other medications, or in measurements of pulmonary function. There was also no significant difference in corrected age at study, race, gender, or length at the time of pulmonary function testing. Infants in the rescue group had a comparable mean FRC (249.4 mL vs 246.2 mL; adjusted 95%CI for difference -15.45, 38.20; P = 0.37) versus placebo. There were no differences in tidal volume or Crs. CONCLUSION: A rescue course of AS significantly increases Crs within 72 h of age and decreases oxygen need in newborn infants, without an adverse impact on pulmonary function or clinical respiratory outcomes at 1-2 years of age [NCT00669383].

Official American Thoracic Society Clinical Practice Guidelines: Diagnostic Evaluation of Infants with Recurrent or Persistent Wheezing.

BACKGROUND: Infantile wheezing is a common problem, but there are no guidelines for the evaluation of infants with recurrent or persistent wheezing that is not relieved or prevented by standard therapies. METHODS: An American Thoracic Society-sanctioned guideline development committee selected clinical questions related to uncertainties or controversies in the diagnostic evaluation of wheezing infants. Members of the committee conducted pragmatic evidence syntheses, which followed the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach. The evidence syntheses were used to inform the formulation and grading of recommendations. RESULTS: The pragmatic evidence syntheses identified few studies that addressed the clinical questions. The studies that were identified constituted very low-quality evidence, consisting almost exclusively of case series with risk of selection bias, indirect patient populations, and imprecise estimates. The committee made conditional recommendations to perform bronchoscopic airway survey, bronchoalveolar lavage, esophageal pH monitoring, and a swallowing study. It also made conditional recommendations against empiric food avoidance, upper gastrointestinal radiography, and gastrointestinal scintigraphy. Finally, the committee recommended additional research about the roles of infant pulmonary function testing and food avoidance or dietary changes, based on allergy testing. CONCLUSIONS: Although infantile wheezing is common, there is a paucity of evidence to guide clinicians in selecting diagnostic tests for recurrent or persistent wheezing. Our committee made several conditional recommendations to guide clinicians; however, additional research that measures clinical outcomes is needed to improve our confidence in the effects of various diagnostic interventions and to allow advice to be provided with greater confidence.

Official American Thoracic Society Clinical Practice Guidelines: diagnostic evaluation of infants with recurrent orPersistent wheezing

Infantile wheezing is a common problem, but there are no guidelines for the evaluation of infants with recurrent or persistent wheezing that is not relieved or prevented by standard therapies. An American Thoracic Society-sanctioned guideline development committee selected clinical questions related to uncertainties or controversies in the diagnostic evaluation of wheezing infants. Members of the committee conducted pragmatic evidence syntheses, which followed the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach. The evidence syntheses were used to inform the formulation and grading of recommendations. The pragmatic evidence syntheses identified few studies that addressed the clinical questions. The studies that were identified constituted very low-quality evidence, consisting almost exclusively of case series with risk of selection bias, indirect patient populations, and imprecise estimates. The committee made conditional recommendations to perform bronchoscopic airway survey, bronchoalveolar lavage, esophageal pH monitoring, and a swallowing study. It also made conditional recommendations against empiric food avoidance, upper gastrointestinal radiography, and gastrointestinal scintigraphy. Finally, the committee recommended additional research about the roles of infant pulmonary function testing and food avoidance or dietary changes, based on allergy testing. Although infantile wheezing is common, there is a paucity of evidence to guide clinicians in selecting diagnostic tests for recurrent or persistent wheezing. Our committee made several conditional recommendations to guide clinicians; however, additional research that measures clinical outcomes is needed to improve our confidence in the effects of various diagnostic interventions and to allow advice to be provided with greater confidence.