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1.
J Dairy Sci ; 92(11): 5595-606, 2009 Nov.
Article in English | MEDLINE | ID: mdl-19841220

ABSTRACT

The effects of forage source, concentration of metabolizable protein (MP), type of carbohydrate, and their interactions on nutrient digestibility and production were evaluated using a central composite treatment design. All diets (dry basis) contained 50% forage that ranged from 25:75 to 75:25 alfalfa silage:corn silage. Rumen-degradable protein comprised 10.7% of the dry matter (DM) in all diets, but undegradable protein ranged from 4.1 to 7.1%, resulting in dietary MP concentrations of 8.8 to 12.0% of the DM. Dietary starch ranged from 22 to 30% of the DM with a concomitant decrease in neutral detergent fiber concentrations. A total of 15 diets were fed to 36 Holstein cows grouped in 6 blocks. Each block consisted of three 21-d periods, and each cow was assigned a unique sequence of 3 diets, resulting in 108 observations. Milk production and composition, feed intake, and digestibility of major nutrients (via total collection of feces and urine) were measured. Few significant interactions between main effects were observed. Starch concentration had only minor effects on digestibility and production. Replacing corn silage with alfalfa decreased digestibility of N but increased digestibility of neutral detergent fiber. Increasing the concentration of MP increased N digestibility. The concentration (Mcal/kg) of dietary digestible energy (DE) increased linearly as starch concentration increased (very small effect) and was affected by a forage by MP interaction. At low MP, high alfalfa reduced DE concentration, but at high MP, increasing alfalfa increased DE concentration. Increasing alfalfa increased DM and DE intakes, which increased yields of energy-corrected milk, protein, and fat. Increasing MP increased yields of energy-corrected milk and protein. The response in milk protein to changes in MP was much less than predicted using the National Research Council (2001) model.


Subject(s)
Dairying , Diet/veterinary , Dietary Carbohydrates/metabolism , Dietary Proteins/metabolism , Digestion/physiology , Lactation/physiology , Ammonia/metabolism , Animal Feed , Animal Nutritional Physiological Phenomena , Animals , Cattle , Eating/physiology , Energy Intake/physiology , Energy Metabolism , Female , Least-Squares Analysis , Manure/analysis , Milk/chemistry , Milk/metabolism , Nitrogen/metabolism
2.
J Dairy Sci ; 92(11): 5607-19, 2009 Nov.
Article in English | MEDLINE | ID: mdl-19841221

ABSTRACT

Effects of forage source, concentration of metabolizable protein (MP), and type of carbohydrate on manure excretion by dairy cows and production of ammonia from that manure were evaluated using a central composite experimental design. All diets (dry basis) contained 50% forage that ranged from 25:75 to 75:25 alfalfa silage:corn silage. Diets contained 10.7% rumen-degradable protein with variable concentrations of undegradable protein so that dietary MP ranged from 8.8 to 12%. Starch concentration ranged from 22 to 30% with a concomitant decrease in neutral detergent fiber. A total of 15 diets were fed to 36 Holstein cows grouped in 6 blocks. Each block was a replicated 3 x 3 Latin square resulting in 108 observations. Manure output (urine and feces) was measured using total collection, and fresh feces and urine were combined into slurries and incubated for 48 h to measure NH3-N production. Feces, urine, and manure output averaged 50.5, 29.5, and 80.1 kg/d, respectively. Manure output increased with increasing dry matter intake (approximately 3.5 kg of manure/kg of dry matter intake), increased concentrations of alfalfa (mostly via changes in urine output), and decreased concentrations of starch (mostly via changes in fecal output). The amount of NH3-N produced per gram of manure decreased with increasing alfalfa because excreted N shifted from urine to feces. Increasing MP increased NH3-N produced per gram of manure mainly because of increased urinary N, but increased fecal N also contributed to the manure NH3. Manure NH3-N production per cow (accounts for effects on manure production and NH3-N produced per unit of manure) was least and milk protein yields were maximal for diets with high alfalfa (75% of the forage), moderate MP (11% of diet dry matter), and high starch (30% of diet dry matter).


Subject(s)
Ammonia/metabolism , Cattle/physiology , Diet/veterinary , Dietary Carbohydrates/metabolism , Dietary Proteins/metabolism , Manure/analysis , Nitrogen/metabolism , Animals , Cattle/metabolism , Dairying , Eating/physiology , Female , Potassium/metabolism
3.
J Dairy Sci ; 90(3): 1452-9, 2007 Mar.
Article in English | MEDLINE | ID: mdl-17297118

ABSTRACT

A sensitive indicator of biotin status for lactating dairy cows is necessary to understand factors that affect milk yield responses to biotin supplementation. 3-Hydroxyisovaleric acid (3HIA) is an alternative metabolite in the pathway of Leu catabolism when the biotin-dependent enzyme methylcrotonyl-coenzyme A carboxylase is limiting. We evaluated urinary excretion of 3HIA as a determinant of biotin status in lactating dairy cows. We hypothesized that high-producing cows would have a greater biotin requirement and excrete more 3HIA than low-producing cows and that biotin supplementation would decrease 3HIA excretion. Twenty high-producing and 20 low-producing Holstein cows (43 +/- 5 and 23 +/- 4 kg/d of milk, respectively) were fed diets that contained either 0 or 0.96 mg/kg of supplemental biotin. On d 16 cows were given an intraruminal infusion of 1.4 mol of isovaleric acid and urine was sampled. Biotin supplementation did not affect basal urinary excretion of 3HIA. The infusion of isovaleric acid increased urinary excretion of 3HIA (maximum at 8 h after infusion), but biotin supplementation did not attenuate this increase. The increase in urinary 3HIA excretion was less for low-producing cows than for high-producing cows. Biotin increased yields of milk and milk components in high-producing cows but had no effect in low-producing cows. However, potential measures of biotin status (concentrations of avidin-binding substances in the plasma, milk, and urine, and urinary 3HIA excretion) responded similarly to biotin supplementation for both high- and low-producing cows. A sensitive indicator of biotin status for lactating dairy cows is still needed.


Subject(s)
Biotin/administration & dosage , Cattle/physiology , Diet/veterinary , Dietary Supplements , Lactation/physiology , Animals , Dairying , Fatty Acids, Volatile/metabolism , Female , Milk/chemistry , Milk/metabolism , Rumen/chemistry , Rumen/metabolism , Time Factors , Valerates/administration & dosage , Valerates/urine
4.
J Theor Biol ; 218(1): 13-33, 2002 Sep 07.
Article in English | MEDLINE | ID: mdl-12297067

ABSTRACT

The mathematical formalism of the steady-state Poisson equation is applied to a variant of Freeman Dyson's "Toy Model" for a first origin. Our kinetic approach allows for an examination of the requisite conditions under which metabolism is quantized into discrete eigenstates (e.g. Dyson's disordered, saddle point, and metabolically active toy cell states). The surface reaction machinery additionally allows for more realistic modeling, whence the crucial role of sticking coefficients (catalyst precursors) as prebiotic selectors emerges. In our interior source model, a steady influx of vent nutrients fuels the intracellular synthesis of (impermeable) monomers within a rock-encradled cavity. Random adsorptions and desorptions occur at inactive "cell" wall sites (where the inert monomers remain impermeable until their eventual return to the intracellular metabolite pool). Occasionally, metabolizing reactions also occur due to endogeneous source monomers adsorbing at their "active" sites. Dyson's mean field approach is used to simplify the species-specific sticking coefficients at empty active (substrate) sites to functions of the fraction x of sites occupied by (catalytically) active monomers. In short, our work suggests that disorder-order transition models based on random drift between discrete metabolic eigenstates (Dyson's Toy Model) do not, in general, extend to more realistic metabolisms. From a perspective based on quasi-random feedback kinetics, the contraindication for discretization (spontaneous generation) in non-autocatalytic metabolisms is consistent with the emergence of ordered metabolism under hydrothermal driving forces, a provisio the occurrence of each period of vent dormancy coincides with a discrete zero-source (dormant) metabolic state. Cell drift to higher order is induced by the random reactions which happen to enhance the substrate specificity (chemical selectivity) of the sticking coefficients for active monomers. The result is stronger sink effects for metabolizing species, whence active adsorptions are promoted in favor of inactive adsorptions at substrate sites. Positive feedback plays a crucial role in preserving ("propagating") order in the cell wall reaction kinetics and is held in check by negative feedback inhibition of excessive cell growth. Finally, the eventual desorption of randomly growing dysfunctional proteins is postulated as a deterrent to deterioration catastrophes.


Subject(s)
Cell Wall/metabolism , Models, Biological , Selection, Genetic , Animals , Biological Evolution , Chemical Phenomena , Chemistry, Physical
5.
J Colloid Interface Sci ; 238(2): 296-309, 2001 Jun 15.
Article in English | MEDLINE | ID: mdl-11374925

ABSTRACT

Quantifying the role of surface shape and physicochemical surface conditions on the interfacial reactivity of particles and substrates is fundamental to a multitude of natural and engineered surface adsorption phenomena. We consider continuum/jump regime adsorption at the gas or liquid interface of arbitrary regular solid surfaces with heterogeneous surface features. In particular, the 3-D boundary value problem (based on Laplace's diffusion equation) is converted into a 2-D integral equation for the adsorbate concentration at the particle surface. This accommodates numerical descretization via the implementation of 2-D Gauss-Legendre quadratures on an arrangement of high- and low-adsorption patch trace sites constructed to completely cover the particle surface. A generalized computer program is developed to solve the resulting linear algebra problem for the unkown local adsorption current densities. We investigate the role of various distributions of high- and low-adsorption sites for a generalized class of spheres which includes the DNA-like shaped twisted spheres. The biological implications of the role of surface curvature on interfacial adsorption/reactivity at particle surfaces are also discussed. Copyright 2001 Academic Press.

6.
J Anim Sci ; 79(1): 155-66, 2001 Jan.
Article in English | MEDLINE | ID: mdl-11204696

ABSTRACT

Intestinal absorption mechanisms of young calves change rapidly during the first 24 h postpartum and subsequently effect the absorption efficiencies of a wide range of compounds. This study was conducted to determine absorption efficiencies of (p,p'-dichlorodiphenyl)dichloroethylene (DDE), 2,2',4,4',5,5'-hexachlorobiphenyl (PCB-153), and 1,2,3,4,6,7,8,9-octachlorodibenzo-p-dioxin (OCDD) when administered in colostrum to neonatal calves. Four male Holstein calves were given a single oral dose containing 100 mg each of DDE, PCB-153, and OCDD either 1 h (n = 2) or 65 h (n = 2) postpartum to determine whether time of exposure influenced the rate or extent of absorption. Another male calf received 100 mg each of DDE and OCDD 1 h postpartum. One gram of chromic oxide (Cr2O3) was administered as a digestion marker to dosed calves. Two male calves, receiving only colostrum, served as controls. Serum IgG concentrations indicated that the 1-h calves absorbed 20 to 37% of the ingested IgG and 65-h calves < 2%; therefore, the gut absorption mechanisms had changed by 65 h. Plasma DDE, PCB-153, and OCDD profiles did not differ based on time of exposure, suggesting that their mechanism of absorption was not influenced by the changing gut. Trapezoidal area under the curve to the last time point values indicated that, during the trial, relative plasma organochlorine concentrations amounted to PCB-153 > DDE > OCDD. Tissue concentrations were similar across treatment groups, with DDE and PCB-153 residues concentrating in adipose tissue and OCDD in the liver. Absorption efficiencies, calculated from fecal recoveries, were >97%, >74%, and >72% for DDE, PCB-153, and OCDD, respectively. These doses of DDE, PCB-153, and OCDD (2.5 +/- 0.1 mg/kg) did not produce signs of toxicosis based on detailed clinical observations, serum clinical chemistry, and gross and histological observations at necropsy. The results of this study indicate that DDE, PCB-153, and OCDD were absorbed and distributed similarly in calves exposed 1 or 65 h postpartum and did not induce toxicosis when administered in combination at these concentrations.


Subject(s)
Animals, Newborn/metabolism , Cattle/metabolism , Insecticides/pharmacokinetics , Polychlorinated Dibenzodioxins/analogs & derivatives , Animals , Chromium/analysis , Colostrum/chemistry , Dichlorodiphenyl Dichloroethylene/pharmacokinetics , Gas Chromatography-Mass Spectrometry , Immunoglobulin G/analysis , Intestinal Absorption/drug effects , Male , Milk/chemistry , Polychlorinated Biphenyls/pharmacokinetics , Polychlorinated Dibenzodioxins/pharmacokinetics , Tissue Distribution
7.
J Anim Sci ; 79(12): 3148-57, 2001 Dec.
Article in English | MEDLINE | ID: mdl-11811471

ABSTRACT

In Exp. 1, 36 individually penned steers (initial BW = 294 +/- 3.8 kg) were used to determine effects of dietary CP percentage and programming gain on performance and carcass characteristics. Steers were fed to achieve a predicted gain of 1.13 kg/d for the first 84 kg of gain and 1.36 kg/d for the next 124 kg of gain and were offered feed for ad libitum consumption for the final 58 kg of gain before slaughter. In these three phases of growth, steers were fed diets, sequentially, with the following CP percentages: HHH (16, 13.5, and 12.5%), LHH (9, 13.5, and 13%), or LLL (9, 9, and 9%). When predicted gain was 1.13 kg/d, ADG was greater (P < 0.01) for steers in the HHH (1.09 kg/d) vs LHH and LLL (0.83 kg/d) systems. When predicted gain was 1.36 kg/d, ADG and gain efficiency were greatest (P < 0.01) for steers in the LHH system. Overall ADG and gain efficiency were greater (P < 0.01) for steers in the HHH (1.46 kg/d, 0.194) and LHH systems (1.38 kg/d, 0.190), compared with steers in the LLL (1.21 kg/d and 0.166) system. Carcass fat thickness was lower for steers in the LHH (0.74 cm) system than for steers in the LLL system (1.09 cm). In Exp. 2, 18 individually penned steers (initial BW = 225 +/- 5.8 kg) were either offered a 13% CP diet for ad libitum intake (AL) throughout the 134-d experiment or fed a high- (16% CP; PI-HH) or low- (10% CP; PI-LH) CP diet and fed to achieve a predicted gain of 1.13 kg/d for the first 85 d of the experiment. Steers in the PI-HH and PI-LH feeding regimens were then offered a 13% CP diet for ad libitum consumption from d 86 to 134. Fractional protein accretion rate was greater (P < 0.01) for steers in the PI-HH and PI-LH feeding regimens than for steers in the AL regimen at d 92, 106, and 120. Fractional breakdown and synthesis rates were not affected (P = 0.63) by feeding regimen. Increased ADG and gain efficiency of steers during compensatory growth periods may in part be due to greater fractional accretion rates of skeletal muscle protein.


Subject(s)
Cattle/growth & development , Dietary Proteins/administration & dosage , Meat/standards , Muscle Proteins/metabolism , Muscle, Skeletal/metabolism , Adipose Tissue/anatomy & histology , Animal Feed , Animal Nutritional Physiological Phenomena , Animals , Body Composition , Cattle/metabolism , Food Deprivation , Male , Random Allocation , Weight Gain
9.
Pediatrics ; 106(2 Pt 1): 282-8, 2000 Aug.
Article in English | MEDLINE | ID: mdl-10920152

ABSTRACT

UNLABELLED: Surfactant therapy has become an effective standard therapy for infants with respiratory distress syndrome (RDS). The first dose may be given either as prophylaxis immediately after delivery, or as rescue after an infant has developed RDS. Second and subsequent doses are currently recommended by the manufacturers to be administered at minimal levels of respiratory support. PURPOSE: This study compared the relative efficacy of administering second and subsequent doses of Infasurf surfactant at a low threshold (FIO(2) >30%, still requiring endotracheal intubation) versus a high threshold (FIO(2) >40%, mean airway pressure >7 cm H(2)O) of respiratory support. METHODS: A total of 2484 neonates received a first dose of surfactant; 1267 reached conventional retreatment criteria and were randomized to be retreated according to low- or high-threshold criteria. They were then retreated at a minimum of 6-hour intervals each time they reached their assigned threshold until receiving a maximum of 4 total doses. Subjects were stratified by whether they received their first dose by prophylaxis or rescue and by whether their lung disease was considered complicated (evidence of perinatal compromise or sepsis) or uncomplicated. RESULTS: Among the patients randomized, 33% of prophylaxis and 23% of rescue subjects met criteria for the complicated stratum. Although infants allocated to the high-threshold strategy were receiving slightly more oxygen at 72 hours, there was no difference in the number receiving mechanical ventilation at 72 hours or in the secondary respiratory outcomes (requirement for supplemental oxygen or mechanical ventilation at 28 days, supplemental oxygen at 36 weeks' postconceptional age, inspired oxygen concentration >60% at any time). However, there was a significantly higher mortality for infants with complicated RDS who had received retreatment according to the high-threshold strategy. CONCLUSIONS: We conclude that equal efficacy can be realized by delaying surfactant retreatment of infants with uncomplicated RDS until they have reached a higher level of respiratory support than is the current standard. We speculate that this would result in a substantial cost-saving from less utilization of drug. Conversely, we believe that infants with complicated RDS should continue to be treated by the low-threshold retreatment strategy, which is currently recommended by the manufacturers of the commercially available surfactants.


Subject(s)
Biological Products , Pulmonary Surfactants/administration & dosage , Respiratory Distress Syndrome, Newborn/drug therapy , Combined Modality Therapy , Cost Savings , Dose-Response Relationship, Drug , Drug Administration Schedule , Female , Humans , Infant, Newborn , Intensive Care, Neonatal/economics , Male , Pulmonary Surfactants/economics , Respiration, Artificial , Respiratory Distress Syndrome, Newborn/economics , Treatment Outcome
10.
JAMA ; 284(1): 41, 2000 Jul 05.
Article in English | MEDLINE | ID: mdl-10872008
11.
Perfusion ; 15(2): 161-8, 2000 Mar.
Article in English | MEDLINE | ID: mdl-10789572

ABSTRACT

Severe coagulation defects often develop in neonates undergoing cardiac surgery, both as a result of the surgical intervention, and as pre-existing defects in the hemostatic mechanisms. The following case report describes a newborn patient with complex congenital heart disease and respiratory failure whose pre-operative coagulopathy was aggressively managed prior to surgical correction. A 5-day-old, 2.5 kg child presented with interrupted aortic arch, ventricular septal defect, atrial septal defect, and patent ductus arteriosus. On admission, he was in respiratory arrest suffering from profound acidemia. In addition, the child was hypothermic (30.1 degrees C), septic (Streptococcus viridans), and coagulopathic (disseminated intravascular coagulation-DIC). The patient was immediately intubated and initial coagulation assessment revealed the following: prothrombin time (PT) 48.9 s (international normalized ratio (INR) 15.7), activated partial thromboplastin time (aPTT) >106 s, platelet count 30,000 mm(3), fibrinogen 15 mg dL(-1) and antithrombin III (AT-III) 10%. Before cardiac surgery could be performed, the patient's DIC was corrected with the administration of cryoprecipitate (15 ml), fresh frozen plasma (300 ml), and platelets (195 ml). In spite of the large transfusion of fresh frozen plasma, the AT-III activity, measured as a percentage, remained depressed at 33. Initial thromboelastographic (TEG) determination revealed an index of +2.02, and following 100 IU administration of an AT-III concentrate, declined to -2.32. Sequential TEG profiles were performed over several days, with the results used to guide both transfusion and medical therapy. The congenital heart defect correction was subsequently performed with satisfactory initial results, but the patient developed a fungal infection and expired on the 16th post-operative day. The present case describes techniques of coagulation management for a newborn with both a severe hemostatic defect and congenital heart disease.


Subject(s)
Antithrombin III Deficiency/complications , Antithrombin III/therapeutic use , Disseminated Intravascular Coagulation/therapy , Heart Defects, Congenital/surgery , Preoperative Care , Acidosis, Respiratory/complications , Acidosis, Respiratory/drug therapy , Anti-Bacterial Agents , Blood Coagulation Tests , Colloids/therapeutic use , Combined Modality Therapy , Disseminated Intravascular Coagulation/complications , Dobutamine/therapeutic use , Dopamine/therapeutic use , Drug Therapy, Combination/therapeutic use , Endocarditis, Bacterial/etiology , Fatal Outcome , Fungemia/complications , Heart Defects, Congenital/complications , Heart Diseases/etiology , Heart Failure/etiology , Humans , Infant, Newborn , Male , Nitric Oxide/therapeutic use , Plasma , Platelet Transfusion , Postoperative Complications , Sodium Bicarbonate/therapeutic use , Streptococcal Infections/complications , Streptococcal Infections/drug therapy , Thrombosis/etiology
12.
J Perinatol ; 18(6 Pt 1): 431-5, 1998.
Article in English | MEDLINE | ID: mdl-9848755

ABSTRACT

OBJECTIVE: To compare the effectiveness of a prophylactic surfactant treatment strategy (PRO) to the effectiveness of a rescue (RESC) surfactant treatment strategy in patients at high risk for developing hyaline membrane disease (HMD). STUDY DESIGN: We analyzed data from a retrospective cohort consisting of all patients admitted to the neonatal intensive care units at the centers participating in the recently completed Infasurf-Survanta Comparative Trial. To be in the cohort, a patient had to be admitted during the trial, be <48 hours of age on admission, have a gestational age of <30 weeks, have a birth weight of 501 to 1250 gm, and be free of congenital anomalies. Twelve centers participated in this study. They contributed 1097 patients of whom 381 were treated with a PRO strategy. RESULTS: Survival was significantly higher in the PRO-strategy patients (84% vs 72%, p < 0.05) as was survival without oxygen requirement at a postconceptional age of 36 weeks (60% vs 46%, p < 0.05). In addition, the patients with PRO had a lower prevalence of grade III and IV intraventricular hemorrhage (IVH, 9% vs 14%, p < 0.05). All analyses were controlled for birth weight and type of study center. CONCLUSION: These data support the conclusion that using a PRO treatment strategy results in improved survival in patients at risk for developing HMD. A PRO treatment strategy may also decrease the likelihood of developing a severe IVH.


Subject(s)
Hyaline Membrane Disease/prevention & control , Infant Mortality , Infant, Very Low Birth Weight , Pulmonary Surfactants/therapeutic use , Cerebral Hemorrhage/complications , Humans , Infant, Newborn , Retrospective Studies , Risk Factors
13.
J Anim Sci ; 76(8): 2197-204, 1998 Aug.
Article in English | MEDLINE | ID: mdl-9734872

ABSTRACT

Shortly after birth, plasma glucose and fructose concentrations of the neonate decline and thus leave blood sugar below the homeostatic mode. Two trials were conducted to determine the plasma glucose and fructose kinetics in control and supplemented calves for 108 h after birth. In the short-term trial, six Holstein calves were given 40 g of either fructose, lactose, or water (control) orally at 1 and 96 h after birth. Treatments were administered with a colostrum substitute (Life Boost) at 1 h and whole milk at 96 h. Rectal temperatures and changes in plasma glucose and fructose concentrations were monitored at close intervals for 12 h after supplementation. In the long-term trial, 15 Holstein calves were given 40 g of either lactose, fructose, or water (control) at 1 h after birth and at 12-h intervals for 81 h. Plasma glucose and fructose concentrations were determined before and 4 h after each of the seven feedings. Early postpartal feeding of fructose suppressed plasma glucose (approximately 50%), with a reciprocal rise in plasma fructose. Irrespective of treatment, plasma glucose concentrations did not stabilize (approximately 100 mg/dL) until 17 to 24 h after birth. After 24 h, lactose supplements increased concentrations of plasma glucose 4 h after supplementation (169.7 +/- 8.2 mg/dL), compared with those in calves that did not receive the additional lactose. After 24 h, fructose supplements did not affect plasma glucose, but plasma fructose concentrations increased (82.6 +/- 12.4 mg/dL) 4 h after administration. The response to fructose supplements declined by 11.4 mg x dL(-1) x d(-1). Fructose was not detected in the plasma of control or lactose-treated calves after 17 h after birth. Calves that received fructose supplements had rectal temperatures 8 and 10 h after birth that were higher than those of the other calves. The mechanisms of sugar metabolism change quickly following birth. Oral sugar supplements increase the total plasma sugar concentrations of treated calves.


Subject(s)
Animals, Newborn/metabolism , Blood Glucose/metabolism , Cattle/metabolism , Fructose/blood , Lactose/metabolism , Animals , Animals, Newborn/blood , Body Temperature , Cattle/blood , Energy Metabolism , Female , Fructose/administration & dosage , Fructose/metabolism , Lactose/administration & dosage , Linear Models , Male , Temperature
14.
J Extra Corpor Technol ; 30(2): 83-90, 1998 Jun.
Article in English | MEDLINE | ID: mdl-10182118

ABSTRACT

The physical process of extracorporeal membrane oxygenation (ECMO) results in derangement of the hemostatic mechanism, which may lead to increased morbidity, secondary to the disease process. The purpose of this study was to evaluate the hematological status of neonates undergoing ECMO therapy, and to evaluate coagulation tests in predicting hemorrhagic risk. Following Institutional Review Board approval, 30 patients undergoing ECMO treatment were retrospectively entered into this study. Medical records were reviewed and indicators of hemostasis, transfusion, morbidity, and outcomes recorded. Assessment of coagulation was determined through serial analysis of platelet count, fibrinogen concentration, prothrombin time (PT), activated partial thromboplastin time (aPTT), antithrombin III, fibrin split products, D-dimers, plasma free hemoglobin, activated clotting time, ionized calcium, and thrombelastography (TEG). Median total transfusion requirements for all patients were 1.79 ml/kg/ECMO hr. Fifty-seven percent of the 30 patients were diagnosed as coagulopathic according to Extracorporeal Life Support Organization standards. Patients were separated into either a hemorrhagic group (HEM, > 2.0 ml/kg/ECMO hr, n = 13) or a nonhemorrhagic group (N-HEM, n = 17), with HEM patients requiring twice the transfusion volume of N-HEM (p < 0.0001). Hemorrhagic complications were reported in 53.8% of the HEM patients vs. 35.3% in the N-HEM group. HEM patients were transfused with significantly greater quantities of platelets on days 1, 3, 5, and 8 and packed red blood cells on day 7 when compared to N-HEM (p < 0.05). TEG determination showed significant differences between groups on days 3 and 6 (p < 0.005), and 8 (p < 0.05). Derangements in hemostasis resulting from ECMO are profound, with methods of assessing coagulation complicated by both the variability in patient condition and lack of specificity of laboratory tests. Interpretation of TEG data has shown to be a valuable supplement for managing this challenging patient population.


Subject(s)
Extracorporeal Membrane Oxygenation , Hemostasis/physiology , Antifibrinolytic Agents/blood , Antithrombin III/analysis , Antithrombins/analysis , Blood Coagulation/physiology , Blood Transfusion , Calcium/blood , Erythrocyte Transfusion , Extracorporeal Membrane Oxygenation/adverse effects , Female , Fibrin Fibrinogen Degradation Products/analysis , Fibrinogen/analysis , Hemoglobins/analysis , Hemorrhage/etiology , Humans , Infant, Newborn , Male , Partial Thromboplastin Time , Platelet Count , Platelet Transfusion , Prothrombin Time , Retrospective Studies , Serine Proteinase Inhibitors/blood , Thrombelastography , Treatment Outcome , Whole Blood Coagulation Time
15.
Pediatrics ; 100(1): 31-8, 1997 Jul.
Article in English | MEDLINE | ID: mdl-9200357

ABSTRACT

OBJECTIVE: To compare the relative safety and efficacy of Infasurf (calf lung surfactant extract; ONY, Inc, Amherst, NY, IND #27169) versus Survanta (Beractant, Ross Laboratories, Columbus, OH) in reducing the acute severity of respiratory distress syndrome (RDS) when given at birth and to infants with established RDS. DESIGN: A prospective, randomized, double-blind, multicenter clinical trial. SETTING: Thirteen neonatal intensive care units participated in the treatment arm: seven of these concurrently participated in the prevention arm. PATIENTS: The treatment arm enrolled infants of

Subject(s)
Biological Products , Pulmonary Surfactants/therapeutic use , Respiratory Distress Syndrome, Newborn/drug therapy , Age Factors , Apgar Score , Birth Weight , Double-Blind Method , Female , Gestational Age , Humans , Infant, Newborn , Infant, Small for Gestational Age , Male , Prospective Studies , Pulmonary Surfactants/administration & dosage , Pulmonary Surfactants/adverse effects , Respiratory Distress Syndrome, Newborn/prevention & control
16.
Perfusion ; 12(2): 143-9, 1997 Mar.
Article in English | MEDLINE | ID: mdl-9160366

ABSTRACT

This paper describes an unusual complication of membrane dysfunction during extracorporeal membrane oxygenation (ECMO) for treatment of neonatal respiratory distress. A 2.8-kg term infant presented to our facility in severe respiratory distress and was diagnosed with primary pulmonary hypertension. After routine priming of the extracorporeal circuit, the patient was placed on veno-arterial ECMO with 8 F arterial and 12 F venous cannulae. Transfusion criteria were established which included trigger values of the following: platelet count 100,000/microliters, fibrinogen 150 mg/dl, haematocrit 40%. The ECMO course was uneventful until approximately the 132nd hour on support when the patient developed a consumptive coagulopathy, as evidenced by 55-60% reductions in both platelet count and fibrinogen concentrations, despite transfusion therapy. Total autogeneic blood product transfusion during the first 120 h of ECMO averaged 4.4 +/- 2.2 ml/h, while the transfusion rate for the final 35 h was 7.8 +/- 3.5 ml/h. Coinciding with this rise in transfusion requirements was an increase in transmembrane pressure from 0.29 to 1.52 mmHg/ml blood flow. The patient was separated from ECMO after 175 h due to a continuing coagulopathy and haemothorax. The patient was then treated with nitric oxide therapy before succumbing on the twelfth postoperative day due to refractory respiratory failure. The circuit was dissected and significant clots found in both the venous bladder and oxygenator. In addition, approximately one-third of the membrane compartment had a 'fused' circumferential pattern of dessicated clot which interrupted blood path continuity. In conclusion, this report describes an unusual complication of the ECMO oxygenator that occurred during long-term extracorporeal life support which most likely resulted from a coagulopathy.


Subject(s)
Disseminated Intravascular Coagulation/etiology , Extracorporeal Membrane Oxygenation/adverse effects , Respiratory Distress Syndrome, Newborn/therapy , Blood Transfusion , Disseminated Intravascular Coagulation/blood , Disseminated Intravascular Coagulation/therapy , Fatal Outcome , Humans , Infant, Newborn , Nitric Oxide/therapeutic use , Thrombelastography
17.
J Extra Corpor Technol ; 27(3): 137-45, 1995 Sep.
Article in English | MEDLINE | ID: mdl-10155358

ABSTRACT

Patients undergoing extracorporeal membrane oxygenation (ECMO) are at an increased risk for developing coagulopathies due to the adverse effects of extracorporeal circulation on the hemostatic mechanism. Methods of determining causative factors of bleeding diathesis are often inconsistent and non-specific. ECMO patients require aggressive transfusion therapy with autogenic blood products to stabilize and maintain hemostasis. The present study evaluated the coagulation status of newborn patients undergoing ECMO therapy, using a viscoelastic monitor (Thrombelastograph -TEG) that measures functional aspects of clot development and stabilization. Seventeen neonatal patients undergoing ECMO for severe respiratory dysfunction were entered into this study. Serial blood samples were obtained and routine coagulation assessment including fibrinogen concentration, platelet count and ionized calcium was performed. In addition, fibrin(ogen) degradation products (FDP), d-Dimers, antithrombin III and plasma free hemoglobin were measured. Transfusion indicators were established and total transfusion requirements recorded. TEG profiles were determined with the use of heparinase, an enzyme that degrades heparin but has little effect on other coagulation factors. The most commonly encountered complication was hemorrhaging which was diagnosed by laboratory and clinical assessment in 11 of 17 patients. Transfusion requirements (measured in ml/kg/ECMO hour) were the following: packed red blood cells--1.34 +/- 0.5; platelets--0.71 +/- 0.57; fresh frozen plasma--0.09 +/- 0.12; cryoprecipitate 0.05 +/- 0.05. Thrombelastograph profiles reflected hemostatic conditions that ranged from severe coagulopathies (DIC) to hypercoagulability. Interpretation of TEG profiles identified hemostatic abnormalities in 57 of 101 profiles (46.5%), with the most common etiology related to platelet dysfunction.(ABSTRACT TRUNCATED AT 250 WORDS)


Subject(s)
Blood Coagulation Disorders/blood , Extracorporeal Membrane Oxygenation/adverse effects , Thrombelastography/methods , Blood Coagulation Disorders/etiology , Blood Coagulation Disorders/therapy , Blood Transfusion , Female , Humans , Infant, Newborn , Male , Monitoring, Physiologic/instrumentation , Monitoring, Physiologic/methods , Thrombelastography/instrumentation , Treatment Outcome
19.
Drug Saf ; 10(2): 170-81, 1994 Feb.
Article in English | MEDLINE | ID: mdl-8011182

ABSTRACT

Nonsteroidal anti-inflammatory drugs (NSAIDs) are associated with significant upper gastrointestinal (GI) toxicity, with a relative risk of approximately 3. This is supported by evidence drawn from randomised controlled trials [of aspirin (acetylsalicylic acid)], cohort studies and case-control studies. The risk is increased with higher doses of medication, shorter treatment duration and concomitant corticosteroid use. Elderly patients and those with a history of GI illness are also at increased risk. Ibuprofen may be associated with a lower, and piroxicam with a higher, risk of complications. There are only preliminary data regarding an association between NSAIDs and small and large intestinal complications. Therapeutic alternatives which may confer a lower risk of significant GI toxicity include enteric-coated preparations, non-acetylated salicylates, and NSAIDs taken in conjunction with misoprostol. Epidemiological data regarding these alternatives are sparse.


Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/adverse effects , Gastrointestinal Diseases/chemically induced , Gastrointestinal Diseases/epidemiology , Case-Control Studies , Humans , Randomized Controlled Trials as Topic
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