The method of long-term catheterization of the vena jugularis in pigs

Continuous fluid infusion per rectum compared with intravenous fluid infusion in pigs

BACKGROUND

Peripheral blood vessels in pigs are not easily accessible, making placement of intravenous catheters difficult. Alternative methods to intravenous administration of fluids, such as administering fluids via the rectum (proctoclysis), are warranted in pigs.

HYPOTHESIS

Administration of polyionic crystalloid fluids via proctoclysis results in hemodilution changes similar to intravenous administration. The objectives of this study were to evaluate the tolerance for proctoclysis in pigs and compare analytes before and after intravenous or proctoclysis therapy.

ANIMALS

Six healthy, growing, academic institution-owned pigs.

METHODS

Randomized, cross-over design clinical trial, with 3 treatments (control, intravenous, and proctoclysis) with a 3-day washout period. The pigs were anesthetized and jugular catheters were placed. A polyionic fluid (Plasma-Lyte A 148) was administered at 4.4 mL/kg/h during the intravenous and proctoclysis treatments. Laboratory analytes, including PCV, plasma, and serum total solids, albumin, and electrolytes were measured over 12 h at T0 , T3 , T6 , T9 , and T12 . Effects of treatment and time on analytes were determined by analysis of variance.

RESULTS

Proctoclysis was tolerated by pigs. Albumin concentrations decreased during the IV treatment between T0 and T6 (least square mean of 4.2 vs 3.9 g/dL; 95% CI of mean difference = -0.42, -0.06; P = .03). Proctoclysis did not significantly affect any laboratory analytes at any time points (P > .05).

CONCLUSIONS AND CLINICAL IMPORTANCE

Proctoclysis did not demonstrate hemodilution similar to intravenous administration of polyionic fluids. Proctoclysis might not be an effective alternative to the intravenous administration of polyionic fluids in healthy euvolemic pigs.

An Insight into the Structural Diversity and Clinical Applicability of Polyurethanes in Biomedicine

Due to their mechanical properties, ranging from flexible to hard materials, polyurethanes (PUs) have been widely used in many industrial and biomedical applications. PUs' characteristics, along with their biocompatibility, make them successful biomaterials for short and medium-duration applications. The morphology of PUs includes two structural phases: hard and soft segments. Their high mechanical resistance featuresare determined by the hard segment, while the elastomeric behaviour is established by the soft segment. The most important biomedical applications of PUs include antibacterial surfaces and catheters, blood oxygenators, dialysis devices, stents, cardiac valves, vascular prostheses, bioadhesives/surgical dressings/pressure-sensitive adhesives, drug delivery systems, tissue engineering scaffolds and electrospinning, nerve generation, pacemaker lead insulation and coatings for breast implants. The diversity of polyurethane properties, due to the ease of bulk and surface modification, plays a vital role in their applications.