The effect of temperature on di(2-ethylhexyl) phthalate leaching from PVC infusion sets exposed to lipid emulsions.

Poly vinyl chloride (PVC) infusion equipment contains substantial amounts of the plasticiser di(2-ethylhexyl) phthalate (DEHP). We determined the amount of DEHP leached from Mediplus Dual TIVA(®) Infusion sets, into lipid and non-lipid infusates. Two propofol admixtures (Diprivan(®) 1%, Propoven(®) 1%), Intralipid(®) 10% and 0.9% saline were evaluated as infusates. Solutions were infused through TIVA sets at 12 ml.h(-1) for 6 h at 24, 32 and 37 °C. In addition, TIVA sets were filled with 2 ml infusates, sealed and incubated at 24 and 37 °C for 6 h. Di(2-ethylhexyl) phthalate was detected in all lipid infusates after dynamic infusion and static contact, and in 0.9% saline after dynamic infusion at 37 °C. At 32 and 37 °C, the quantity of di(2-ethylhexyl) phthalate leaching into the lipid infusates may exceed the recommended maximum exposure amount set by the European Union for DEHP of 20-48 µg.kg(-1) day(-1) if lipid based infusates are used for sedation or intravenous feeding of infants or neonates.

The state of implantable pain therapies in the United States: a nationwide survey of academic teaching programs.

UNLABELLED: The purpose of this questionnaire survey was to provide an overview of anesthesiology pain fellowship programs in the United States with regard to implantation of spinal cord stimulators (SCS) and opioid infusion devices. Of the 95 programs solicited, 80% responded to questions pertaining to the prevalence of use and technical considerations of implantation. Of the responding programs, 87% report implanting SCS, and 84% report implanting neuraxial infusion pumps. All programs perform a stimulation or infusion trial before implantation, although the duration varied from a trial in the operating room at the time of implantation to 25 days. Of the programs, 83% implant cylindrical leads, and 17% implant flat leads via laminectomy for their nonrevision SCS implants. Morphine, bupivacaine, hydromorphone, and baclofen are the most commonly used drugs and are used in implanted pumps by >50% of respondents. The question of industry-sponsored pain fellow education in implantable techniques is addressed. IMPLICATIONS: Of the pain teaching programs in the United States, 80% responded to a questionnaire eliciting information about the implantation of spinal cord-stimulating and opioid infusion devices. The range and diversity of responses imply a lack of agreement about implantation techniques, drugs, and protocols.

Effects of phlebotomy and autologous blood transfusion on oxygen transport in the racehorse.

Because the haemoglobin concentration Hb[ during exercise may be at the upper limit of blood viscosity for effective oxygen delivery, we hypothesised that administration of blood would not further enhance oxygen delivery or exercise capacity. Six Thoroughbred geldings were used in 5 incremental treadmill exercise tests over a period of 4 weeks. The first test was performed 6 days prior to phlebotomy, which involved the removal of 20 ml/kg bwt of venous blood. Exercise tests were performed at 1, 8 and 15 days after blood removal. Six days after the 15 day post phlebotomy exercise test, blood from each horse was reinfused and the final test performed 24 h after blood reinfusion. During the 3 weeks following blood collection, the blood, collected into acid citrate dextrose, was stored at 3 degrees C. Each exercise test involved measurements of arterial and mixed venous blood gases, plasma lactate concentrations, heart rate and VO2 using an open flow system. Cardiac output was measured by direct Fick. The removal and reinfusion of blood had significant effects on packed cell volume (PCV) with the lowest PCV value during exercise of 0.57 +/- 0.04 l/l being recorded in the second post phlebotomy test and the highest value of 0.67 +/- 0.04 l/l found after blood reinfusion. There were no significant effects of phlebotomy or blood reinfusion on arterial blood gas values. However, arteriovenous oxygen content difference was significantly altered by phlebotomy and reinfusion. The maximal values during the 3 tests following phlebotomy were significantly lower (P < 0.05) by about 7% than those before phlebotomy and after blood reinfusion, mirroring the alterations in Hb[. There was no significant effect of phlebotomy or blood reinfusion on heart rate but stroke volume was significantly higher (P < 0.01) during the 3 post phlebotomy tests than for the control or blood reinfusion tests. There was no significant effect of phlebotomy or blood reinfusion on either the submaximal or maximal values for VO2. No significant effect of blood removal or reinfusion was found on the treadmill run time to fatigue. We concluded that haemodynamic adjustments following phlebotomy or blood reinfusion maintained oxygen delivery during exercise. No detrimental effects on exercise capacity were found from phlebotomy nor beneficial effects from autologous blood transfusion. However, it should be noted that the extent of change induced in Hb[ was relatively small and with the number of horses in the study, the experimental power was not great.

Induced diarrhoea in horses. Part 1: Fluid and electrolyte balance.

Sodium, potassium and water balance, and measurements of acid-base status, haematocrit, packed cell volume and plasma total protein, were studied in four adult standardbred geldings following castor oil induced diarrhoea. Castor oil (2 mL kg-1) administration resulted in signs consistent with mild to moderate acute colitis. The total (combined faecal and urinary losses) losses of sodium and potassium ions were 2169 and 2864 mmol, respectively. Faeces constituted the major route for sodium loss, while urine was the major route for potassium loss at all times. Faecal dry matter potassium concentration did not vary significantly at any stage. Faecal dry matter sodium concentration increased significantly, coinciding with the onset of clinical diarrhoea. Faecal water loss increased significantly from 2.15 +/- 0.44 mL kg-1 h-1 to 5.15 +/- 0.92 mL kg-1 h-1 while clinical diarrhoea was observed. While plasma volume (PV) did not vary significantly in this study, there was a trend for PV to decrease while horses were clinically dehydrated.

Induced diarrhoea in horses. Part 2: Response to administration of an oral rehydration solution.

Hydration status, electrolyte balance and acid-base balance were studied in four adult standardbred geldings with castor oil-induced diarrhoea. The horses received an oral rehydration solution (ORS) at a point when signs consistent with mild decreases in effective circulating fluid volume were first detected. Within 1.5 h of ORS administration, all horses exhibited a significant metabolic acidosis. At this time, mean values for venous blood pH, [HCO3], and standard base excess were 7.264 +/- 0.011, 17.7 +/- 0.3 mmol L-1, and -8.2 +/- 0.4 mmol L-1, respectively. Throughout the duration of the study, plasma volume did not change significantly, despite a decreasing trend, which tended to recover towards normal values 8 h after administration of the ORS. Signs of abdominal discomfort were observed in all horses following the last of three doses of ORS (8-10 L) administered at 30 min intervals. Faecal fluid sodium concentration increased significantly with diarrhoea, and reached values fourfold those in normal horses, while faecal dry matter sodium concentration increased exponentially following the onset of clinical signs. Despite this increase in sodium concentration, faecal fluid remained hypotonic at all stages. Our findings suggest that, while ORS can help restore systemic fluid balance, several factors influence their effectiveness. Two likely factors identified in this study were the ionic composition of the ORS as well as the rate of administration. We concluded that the electrolyte composition of current ORS may not be ideal to treat diarrhoea in horses and that administration of 8-10 of ORS every 30 min via nasogastric tube may result in too rapid small intestinal transit to allow sufficient time for absorption.

Electrolytes: clinical applications.

Many factors can influence electrolytes in the horse. With the major electrolytes (sodium and potassium), alterations in serum or plasma values do not reflect changes in total body status. However, estimates of electrolyte alterations may be made by combining assessments of body weight changes with plasma sodium values by using the formula of Edelman et al. In planning electrolyte therapy, it has to be remembered that access to green feed or hay is important in correcting any total body potassium depletion and that diets marginal in sodium may interfere with exercise capacity by limiting sweat production. Free access to salt would seem to be the simplest method to ensure adequate sodium availability. Despite the widespread use of various commercial electrolyte supplements administered in horses' feed, most would appear to be unwarranted. Extensive electrolyte deficits are most likely in endurance horses in which substantial electrolyte losses can occur in the sweat. In such cases and when access to grass or hay is limited, supplementation with sodium and potassium chloride may be useful. Bicarbonate administration appears to have no clinical role in endurance or pleasure horses. However, its use as a buffer to limit the extent of lactic acidosis during galloping exercise has not been resolved.