Bacteria found on intravenous catheters removed from horses

B-mode and color Doppler ultrasonography of normal external jugular vein in donkeys (Equus asinus)

Background

Although the jugular vein is a major important blood vessel in equine, the literature lacks this vessel's normal B-mode and Doppler ultrasonographic examinations in donkeys. Therefore, this study aimed to determine the reference ranges of B-mode and Doppler ultrasonographic indices of jugular veins in healthy adult donkeys (Equus asinus) and the possible effect of examination side (left and right), gender, and body condition on the ultrasonographic measurements of this vessel. B-mode and Doppler ultrasound imaging of the external jugular vein was conducted on 20 adult healthy donkeys of both sexes.

Results

In all donkeys, the jugular vein was 4.01 to 8.1 mm from the body surface. The longitudinal and transverse venous diameters ranged from 3.94 to 10.5 mm and from 0.88 to 1.9 cm, respectively. Moreover, the vein areas varied from 0.61 to 2.83 cm². The reference values of superficial and deep wall thickness (SWT and DWT) were 0.56 ± 0.2 and 0.6 ± 0.13 mm, respectively. The blood velocity, blood follow rate, and congestion index of the external jugular vein can be expected in adult healthy donkeys as a range value from 8.4 to 13.5 cm/sec, from 0.33 to 1.78 ml/min, and from 0.06 to 0.27 cm.sec, respectively. Generally, the vein showed laminar monophasic waveforms. The examination side and gender have no significant effect on the ultrasound measurements of the vein (P > 0.05). Donkeys with a body condition score (BCS) ≥ 3 revealed increases in the depth of the vein (P < 0.05).

Conclusions

The results of this study can be used as reference values and provide a basis for comparison when evaluating donkeys with diseases that affect blood flow in the external jugular vein.

[Venous catheters in horses - early ultrasonographic venous abnormalities and evidence of biofilms]

OBJECTIVE

Complications associated with indwelling intravenous catheters vary from minor to severe. Changes in tissue architecture and vein structure may be detectable prior to clinical alterations. The aim of the study was to characterize and compare changes in a catheterized vein and surrounding tissue by clinical and ultrasonographic examination. Microbiological infestation of catheter specimens was assessed.

MATERIAL AND METHODS

In this prospective, observational, clinical study 55 horses with an indwelling intravenous catheter have been included. Subsequent to catheter placement, vein and surrounding tissue were daily examined clinically and by ultrasonographic examination at predetermined localizations. After sterile removal of the catheters, specimens underwent microbiological testing and scanning electron microscopy. Obtained data were analyzed via descriptive statistics. Thickness of the venous wall was compared at predetermined localizations and time points for several parameters with the help of non-parametric tests (level of significance at p < 0.05, post-hoc Bonferroni correction).

RESULTS

Overall, in 41.8 % of the horses transient alterations (swelling) of the surrounding tissue occurred during catheterization. Median catheterization was 69.5 hours (19 hour-10 days). With ultrasonography, venous valves and collateral vessels could be detected reliably. Significant alterations in wall thickness during catheterization were associated with various factors (location site [p ≤ 0.001], season [p = 0.006], anesthesia [p ≤ 0.001]).Microbiological analysis revealed a positive result in 23.5 %, 12 of the 51 samples; raster electron microscopy showed presence of bacteria in 25.0 %, 4 of the 16 investigated catheter samples.

CONCLUSION AND CLINICAL RELEVANCE

Local tissue changes at the insertion site of the catheter are commonly associated with catheterization, and are easily detectable with ultrasonography. Despite the easy performance in a clinical setting, the benefit of routine ultrasonographic monitoring of catheterized veins might be questionable with regard to early identification and prediction of catheter-associated venous disease. Bacteria might be detectable morphologically on the catheter but frequently lack a positive result from standard bacterial cultivation.

[Catheter-associated complications in the horse - diagnosis and treatment in practice]

Venous diseases due to venous catheters have variable symptoms and clinical progress. They comprise perivenous hematoma, periphlebitis, endophlebitis, phlebothrombosis or septic thrombophlebitis. To diagnose venous disease, a clinical examination (possibillity to distend the vein, swelling, pain, increased skin temperature, and any exudation around the injection site) and an ultrasonographic examination (perivenous tissue, venous wall, venous content) of the vein are performed. Treatment of venous diseases depends on the etiology and pathogenesis and combines the use of anticoagulants (heparin, phenprocoumon), anti-inflammatory and analgesic substances (non-steroidal inflammatory drugs) as well as the application of antibiotics depending on the case. For prevention of venous diseases a careful catheter management is important. This includes in particular the adequate selection of the catheter system (long-term catheter made of polyurethane), catheter care and intensive monitoring. This article reviews the different venous diseases, diagnosis and therapeutic measures in a practical manner.

Evaluation of athletic performance in horses with jugular vein thrombophlebitis: 91 cases (1988-2005)

OBJECTIVE

To evaluate effects of thrombophlebitis of 1 or both jugular veins on athletic performance of horses.

DESIGN

Retrospective case series.

ANIMALS

91 horses with jugular vein thrombophlebitis.

PROCEDURES

Medical records of horses with jugular vein thrombophlebitis examined between 1988 and 2005 were reviewed for signalment, history, clinical signs, diagnosis, and treatment. Performance was evaluated in 2 ways. A questionnaire was used to obtain a subjective assessment from the owner or trainer of the horse's performance after thrombophlebitis, compared with the performance before thrombophlebitis. Racing records from before and after thrombophlebitis were also evaluated.

RESULTS

Thrombophlebitis was diagnosed in 37 horses at the time of admission (group 1), and 54 horses developed thrombophlebitis during hospitalization for an unrelated medical condition (group 2). Twenty-seven of 81 (33%) owners answered the questionnaire, and racing records were available for 31 horses. Performance data were available for 48 horses. Owners reported that all nonracing horses, except 1, had equivalent or better performances after discharge. Twenty-six of 31 (84%) Standardbreds resumed racing; in these horses, there was no significant difference between racing times before and after thrombophlebitis. No significant difference in performance was detected regardless of the primary disease, whether a horse had unilateral or bilateral thrombophlebitis, or the treatment administered.

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggested that the athletic performance of horses used for nonracing events was not affected by thrombophlebitis. Thrombophlebitis in racing Standardbreds was associated with a decreased chance of return to racing; however, performance was not impaired in those that resumed racing.

Blood culture status in mature horses with diarrhoea: a possible association with survival

REASONS FOR PERFORMING STUDY

The incidence and implications of positive blood cultures in mature horses with diarrhoea is unknown. The diagnosis of bacteraemia may alter treatment and prognosis.

HYPOTHESIS

The proportion of horses with diarrhoea that are blood culture positive is higher than previously assumed and a positive blood culture has a negative impact on survival.

METHODS

Blood cultures were taken at admission and 24 h after admission from 31 mature horses with diarrhoea.

RESULTS

Nine (29%) horses were blood culture positive within 24 h of admission. Organisms isolated included Corynebacterium spp. (n = 6), Streptococcus spp. (n = 2), Pantoea agglomerans (n = 1), Gram-negative rod (n = 1), Bacillus spp. (n = 1) and yeast (n = 1). Horses with positive blood cultures were significantly less likely to survive. Prior treatment with antimicrobial drugs had no significant effect on blood culture status. Horses with positive blood cultures had a significantly higher heart rate, packed cell volume (PCV) and plasma potassium concentration at admission, and a higher PCV and lower total plasma protein concentration 24 h after admission.

CONCLUSIONS

Positive blood cultures occur more frequently than previously reported, and may have a negative impact on survival in horses with diarrhoea.

POTENTIAL RELEVANCE

Results of blood cultures may be useful in formulating a prognosis for horses with diarrhoea. Further research is required to determine the effect of antimicrobial treatment on outcome.

Assessment of subclinical venous catheter-related diseases in horses and associated risk factors

A total of 102 horses that had a catheter introduced intravenously to facilitate treatment had the catheterised jugular vein and contralateral vein examined by ultrasound every 48 hours. Subclinical complications were defined by thrombus formation or thickening of the venous wall, and the data were analysed to establish risk factors for the development of these complications. The horses with a rectal temperature above 38.5 degrees C when the catheter was introduced were four times more likely to develop complications, than the horses with a lower temperature. The administration of a NSAID while the catheter was in place reduced the risk of complications developing.

Assessing techniques for disinfecting sites for inserting intravenous catheters into the jugular veins of horses

The sites of insertion of catheters into the jugular veins of six horses were investigated to determine common isolates and to assess the effectiveness of two disinfection protocols with the hair coat left long, clipped or shaved. Skin commensals (Staphylococcus, Streptococcus and Micrococcus species) and environmental contaminants (Bacillus, Enterobacteriaceae, Aspergillus and Mucor species) were the microorganisms most frequently isolated. Chlorhexidine gluconate and povidone-iodine-based skin disinfection protocols resulted in significant reductions in the number of bacterial isolates from clipped sites. With chlorhexidine, there were no significant differences between the reductions observed at sites with the hair coat left long, clipped or shaved.

Trombectomia com cateter de Fogarty no tratamento da tromboflebite jugular experimental em eqüinos

Trombose da veia jugular é problema freqüente na medicina eqüina, implicando muitas vezes em conseqüências fatais. O objetivo deste trabalho foi avaliar em eqüinos a aplicabilidade da trombectomia com cateter de Fogarty, técnica rotineiramente empregada pela medicina humana, no restabelecimento da perviedade vascular. Foram utilizados 10 eqüinos divididos em dois grupos de cinco animais, em que se induziu a trombose da veia jugular direita, através do acesso cirúrgico à veia e aplicação de sutura estenosante e injeção de glicose a 50%. No grupo controle avaliou-se a evolução da tromboflebite sem qualquer tipo de intervenção terapêutica. Os animais do grupo tratado foram submetidos à trombectomia com cateter de Fogarty. Foram avaliados os parâmetros clínicos gerais, regionais, ultra-sonográficos e angiográficos, nos momentos pré-indução (M-PRÉ), indução da trombose (MTI) e 10 dias de evolução da trombose (M10). A técnica empregada induziu a tromboflebite, que obstruiu completamente um segmento da veia jugular de todos os animais. Os animais do grupo controle mantiveram os trombos obstruindo totalmente o lume vascular até o final do período de avaliação, sendo que avaliações regionais mostraram principalmente o edema parotídeo e o ingurgitamento vascular, cranial à tromboflebite da veia jugular. O grupo tratado apresentou as veias jugulares pérvias ao final do experimento, confirmadas pelos exames ultra-sonográficos e angiográficos, com remissão total dos sinais clínicos. Concluiu-se que a técnica da trombectomia com cateter de Fogarty foi eficiente na desobstrução da veia jugular submetida à trombose experimental.

Catheters: a review of the selection, utilisation and complications of catheters for peripheral venous access

Intravenous catheters are used for the administration of medications and fluids and are an integral part of veterinary practice. The aim of catheter use is to optimise administration of medication and minimise complications such as thrombus formation, thrombophlebitis and sepsis. Catheters made from teflon are less flexible, less durable and stimulate more tissue reaction than polyurethane or silicon. However silicon catheters are more expensive and complicated to insert. Generally, for veterinary practice, the biostability and cost of polyurethane catheters make them preferable for short and long-term use. The smallest diameter catheter should be selected to minimise internal vessel wall contact and irritation without compromising medication delivery. The site of insertion varies with individual preference, vessel access and patient compliance. The jugular, cephalic, saphenous, ear, lateral thoracic and subcutaneous abdominal veins are accessible. Hair removal and a thorough aseptic skin preparation should be performed prior to catheter insertion. Daily maintenance is required to detect complications and maximise catheter longevity. Potential complications include thrombus formation, thromboembolism, bacterial colonisation and septicaemia, blood loss and air embolism. Permanent or transient skin dwelling bacteria are commonly isolated if sepsis occurs. The development of novel antiseptic and antibiotic impregnated catheters may reduce the complications associated with catheter infection in the future.

Prophylaxis of intravenous catheter-related thrombophlebitis in cattle

Two methods of preventing intravenous catheter-related thrombophlebitis of the jugular vein, using clinical and ultrasonographic criteria, were compared. The first method consisted of minimising bacteriological contamination by the preparation of the skin as if for surgery. The second method involved the daily subcutaneous administration of low doses of heparin to decrease procoagulant activity. The results showed that the preparation of the skin before the placement of an indwelling catheter in the jugular vein and adequate daily maintenance of the catheter were of great importance in the prevention of thrombophlebitis induced by bacteriological contamination. The use of heparin should be limited to cases that require long-term catheterisation or are predisposed to thrombosis or other clotting abnormalities.