Surveillance of infections associated with intravenous catheters in dogs and cats in an intensive care unit

Imaging of experimental venous thrombus by means of Doppler and CEUS techniques in dogs

Venous thrombosis has been widely studied in humans, but not in dogs. This study was designed to evaluate a venous thrombus in dogs, from creation to solution, by means of various ultrasonographic techniques. Nine healthy Beagle dogs were included in the study. The venous thrombus was formatted by puncturing the lumen of the external jugular veins and then, the veins were examined with B-mode, color Doppler, pulsed-wave Doppler, and contrast-enhanced ultrasound (CEUS) techniques, at regular intervals, within 210-270 min after venipuncture. Haemodynamic parameters were calculated at two different locations, before and after the site of the thrombus formation. The existence of a thrombus was confirmed by CEUS technique. Thrombus volume and echogenicity were evaluated. The results showed that the visualization of the venous thrombus by color Doppler modality was not feasible in some veins. The blood volume was the parameter that could more precisely indicate the presence or absence of a thrombus. In cases where thrombus volume was less than 0.001 cm3, it was impossible to detect its presence using haemodynamic parameters. The CEUS imaging depicted accurately the size and shape of an anechoic venous thrombus, even when its volume was 0.001cm3.

Microorganism colonization of peripheral venous catheters in a small animal clinical setting

OBJECTIVE

To compare the incidence of microorganism colonization of peripheral venous catheters (PVCs) placed in the Emergency Department (ED) to those placed in a routine preoperative setting. The relationship between catheter tip colonization and patient urgency (as assessed by triage priority) was also evaluated.

DESIGN

Prospective, observational study from January 2021 to October 2021.

SETTING

Emergency room and clinical areas of a large, urban, tertiary referral center.

ANIMALS

Three hundred dogs and 94 cats with a PVC in place for a minimum of 24 hours were enrolled in the study.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Two hundred and eighty-eight PVCs were placed in the ED and 106 were placed preoperatively. The overall colonization rate was 10.4% (41/394). Sixteen bacterial and 1 fungal genera were cultured. Eight of these bacterial genera (25/51 [49%] bacterial isolates) were resistant to at least 1 antimicrobial class. Twenty-nine of 288 (10.1%) catheters positive for colonization were placed in the ED, whereas 12 of 106 (11.3%) were placed preoperatively. There was no association between microorganism growth on catheters and clinical area of catheter placement. There was also no association between ED patient urgency and positive catheter tip culture. No significant risk factors were identified predisposing to colonization of PVCs.

CONCLUSIONS

The overall incidence of microorganism colonization of PVCs in this study population was equivalent to, or lower than, previously reported in veterinary literature. There was no statistical difference between the catheters placed in the ED and those placed for routine surgical procedures. Patient urgency did not affect the incidence of positivity of peripheral catheter tip cultures.

Two cases of bloodstream infections associated with opportunistic bacterial species (Enterococcus hirae and Enterobacter xiangfangensis) in companion animals

BACKGROUND

Bloodstream infections are a matter of concern in small animal veterinary practice. Few reports are avaiable, especially regarding the role of opportunistic bacteria in becoming infectious. This report aims to add to the current veterinary literature on two opportunistic bacterial species (Enterococcus hirae and Enterobacter xiangfangensis) associated with bloodstream infections in small animals admitted to the Bologna University Veterinary Hospital.

CASE PRESENTATION

In the first case, a 15-year-old, immunocompromised, cardiopathic dog was admitted to the hospital for anorexia and diarrhea. The patient had a history of previous surgery and hospitalization. After three days, hyperthermia, leukopenia and hyperlactatemia were recorded, and blood culture revealed positivity for Enterococcus hirae, identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The patient's general conditions progressively worsened, and the patient was euthanized. In the second case, a 2-year-old cat with chronic ocular herpesvirus infection and hypertrophic cardiomyopathy was admitted to the hospital for anorexia and hyperthermia. The cat was hospitalized one week before and received antimicrobial treatment for urinary tract infection by Staphylococcus felis. Hypokalemia and lymphopenia were also diagnosed. The patient progressively improved and was discharged after three days. On the same day, blood culture taken at admission revealed positivity for Enterobacter xiangfangensis, identified using MALDI-TOF MS. After five days, the patient returned with neurological symptoms, hypothermia and bradycardia, and was euthanized.

CONCLUSIONS

In small animal veterinary practice, the impact of opportunistic bacterial agents (such as E.hirae and E.xiangfangensis) on bloodstream infections remains unclear. As in human medicine, they can be contracted in every healthcare setting and considered hospital-acquired infections. In this report, we highlighted the threat they pose especially in patients with multiple risk factors. Rapid and accurate diagnostic tools (such as MALDI-TOF MS) could be particularly important for reducing the severity of the infections.

Inflammatory, Mechanical and Infectious Complications Associated with Peripheral Intravenous Catheters in Dogs and Cats: A Risk Factor Analysis

The placement of peripheral intravenous catheters (PIVC) is potentially associated with complications that negatively impact healthcare. Our study investigated factors associated with the occurrence of PIVC-related complications in dogs and cats at a Veterinary Teaching Hospital. The second aim was to determine the prevalence of PIVC bacterial colonization. A total of 76 dogs and 40 cats with PIVCs were evaluated for the occurrence of phlebitis and mechanical complications. The devices were removed when they ceased to be functional or when complications occurred, and the content was submitted for bacterial cultures and antimicrobial susceptibility tests. Both multivariable linear regression models and ROC analysis were employed. Complications were recorded in 46.6% of cases, and 20.7% of catheters yielded a positive culture. Among the isolates, 45% were classified as multi-resistant. In dogs, a ≥36-h indwelling time was associated with an increased risk of complications. Male cats seem more prone to developing complications, while the insertion of PIVCs under sedation may represent a protective factor in this species. In conclusion, PIVC-associated complications were frequently observed, and the high rate of positive culture for PIVCs, together with the presence of multi-resistant isolates, is a cause of concern in a hospital setting.

Peripheral Intravenous Catheter Complications in Hospitalized Cats: An Observational Pilot Study

OBJECTIVES

There is little information about complications associated with peripheral catheter use in cats. The primary objective of this study was to determine the main reason for catheter removal in cats hospitalized in the Intensive Care Unit at a university teaching hospital. The secondary objective was to describe catheter-associated complications in cats hospitalized.

METHODS

All feline patients with peripheral intravenous catheters admitted to the Intensive Care Unit between June and August 2017 were prospectively enrolled in this study. All catheters were evaluated at least 3 times a day per institutional Intensive Care Unit protocol. The catheters were monitored throughout the cat's hospitalization period for development of complications, including occlusion, phlebitis and extravasation. Data collected included patient signalment, reason for hospitalization, catheter size and location, number of hours the catheter remained in place, reason for removal and if the catheter was replaced once removed.

RESULTS

Thirty-four cats were enrolled in the study, and a total of 42 catheters were placed in those cats. Median peripheral IV catheter duration was 23.8 hours (interquartile range [IQR] 13.8-41.3 hours). The most frequent reason for catheter removal was patient discharge from the hospital (24/42, 57.1%). Overall catheter complication rate was 21.4% (9/42). Complications observed included phlebitis, extravasation, patient removal, occlusion, and edema formation.

CLINICAL SIGNIFICANCE

The results of this study conclude that the majority of peripheral IV catheters in cats are removed due to discharge from hospitalization. More studies with a larger population of cats are needed to see if there is a relationship between length of indwelling catheterization and risk of catheter-associated complications.

Prevalence of and risk factors for intravenous catheter infection in hospitalized cattle, goats, and sheep

BACKGROUND

Intravenous catheter (IVC) use in hospitalized ruminants is a common procedure. Limited information is available describing complications associated with IVCs.

HYPOTHESES

Prevalence of IVC infections in hospitalized ruminants is >50%. Intravenous catheters maintained for >5 days are more likely to be infected than those maintained for <5 days. Intravenous catheters placed non-aseptically have a higher risk for infection than those placed aseptically.

ANIMALS

Thirty-four cattle, 39 goats, and 33 sheep were hospitalized in a university teaching hospital.

METHODS

Prospective observational study. The IVCs from cattle, goats, and sheep admitted for medical and surgical procedures were randomly selected and submitted for bacteriological culture and susceptibility testing.

RESULTS

Prevalence values (95% confidence interval) of infected catheters were 61.8 (45.5, 78.1), 51.3 (35.3, 66.7), and 42.4% (25.2, 58.8) in cattle, goats, and sheep, respectively. Coagulase-negative Staphylococcus spp was the most frequently isolated bacterium. Catheter type/placement technique was a significant (P = .03) predictor of IVC infection in goats but not in cattle (P = .65) and sheep (P = .47). Antibiotic use and reason for catheter placement were not significant predictors of IVC infection in all species. Catheters maintained for >4 days had a higher likelihood of being infected than those maintained for <4 days in all species.

CONCLUSIONS AND CLINICAL IMPORTANCE

Clinicians should consider replacing catheters maintained for >4 days to reduce IVC infection.

Vascular ultrasonographic findings in canine patients with clinically diagnosed phlebitis

Peripheral vein phlebitis (inflammation) is a relatively frequent complication in dogs, however, published information on the ultrasonographic characteristics is currently lacking. This prospective, observational study describes the ultrasound (US) characteristics of normal canine cephalic veins, and veins with clinical phlebitis. Correlations among US findings and between US findings versus time that the intravenous catheter was in place were investigated. Safety of the US procedure was evaluated. Fifty patients were prospectively recruited for the study and 18 met the final inclusion criteria. Each patient underwent daily US examinations and was assessed for multiple criteria (vascular wall appearance, compressibility, spontaneity of flow, color fill, and presence/absence of filling defects, flow contour, direction, non‐pulsatility). Characteristics of normal canine cephalic veins were as follows: smooth and thin wall, complete compressibility, no flow disturbances, no filling defects, smooth flow contours, and unidirectional, non‐pulsatile flow with no turbulence. Characteristics of cephalic veins with clinical phlebitis were as follows: wall thickening (83%), decreased compressibility (55%), filling defects consistent with intraluminal thrombus (55%), vessel wall hyperechogenicity (44%), and abnormal color Doppler flow (39%). Significant correlations were found between Doppler filling defects and compressibility, Doppler filling defects and presumed thrombosis, and compressibility and presumed thrombosis (P = .001, P = .001, P = .000, respectively). No correlation was found between the US findings and time the intravenous catheter was in place. Findings indicated that duplex and compressibility US are feasible and safe methods for characterizing and monitoring cephalic veins in dogs with clinical phlebitis.

Aislamiento e identificación de bacterias con potencial nosocomial procedentes de ambientes y superficies de una clínica veterinaria Universitaria del Área Metropolitana del Valle de Aburrá, Antioquia-Colombia

Introducción: las infecciones nosocomiales son aquellas adquiridas por los pacientes durante la hospitalización. Son de gran importancia en medicina humana pero aún se desconoce cuál es su papel en medicina veterinaria.Objetivo: identificar la presencia de bacterias asociadas a infecciones hospitalarias en ambientes y superficies en una clínica veterinaria.Materiales y métodos: se realizaron dos muestreos, se determinó a través de sedimentación y torunda la presencia de bacterias en el ambiente y las superficies de las 8 unidades de la clínica veterinaria. La presencia de nosocomiales se determinó por el crecimiento y purificación en medios diferenciales, la identificación se hizo por descripción macroscópica de las colonias y tinción de Gram y posteriormente se realizó una caracterización bioquímicamente por medio del API20E y API50 CH/E y un antibiograma en las cepas relacionadas con resistencia a antibióticos.Resultados: se obtuvo 95 aislados y se logró determinar la presencia de 28 agentes potencialmente nosocomiales, donde se destaca la presencia de Pseudomonas aeruginosa, Proteus sp. y Staphylococcus sp. microorganismos relacionados con infecciones asociadas a hospitales veterinarios.Conclusiones: se realiza la primera aproximación a este tipo de infecciones en hospitales veterinarios en Antioquia, y se evidencia la circulación en ambiente y superficies de potenciales bacterias nosocomiales en la clínica veterinaria.

Incidence of and associated factors for bacterial colonization of intravenous catheters removed from dogs in response to clinical complications

BACKGROUND

Infection rate associated with intravenous (IV) catheter placement is emerging as an important issue in small animal veterinary medicine, mostly because of the economic costs associated with these infections. Identification of possible associated factors may provide useful information for the surveillance and prevention of such infections.

OBJECTIVES

To determine the incidence of positive bacterial cultures obtained from IV catheters used in dogs hospitalized for at least 48 hours and removed because of clinical complication. To identify the bacteria involved and factors associated with bacterial colonization.

ANIMALS

One-hundred eighty-two dogs that underwent IV catheterization from January 2015 to July 2015 at the Veterinary Teaching Hospital of Alfonso X el Sabio University of Madrid were enrolled in the study.

RESULTS

The bacterial colonization rate of all IV catheters removed in response to clinical complications was 39.6%, the cumulative proportion of catheters that remained in place at 24, 48, and 72 hours after placement was 89.5, 78, and 59.4%, respectively. Multivariable Cox proportional hazards regression indicated significant associations for staff who performed catheterization (junior, P = .002; student, P = .034) and use of steroidal anti-inflammatory drugs (P = .036). The most frequently isolated bacterium was Acinetobacter spp. (21.7%).

CONCLUSIONS AND CLINICAL IMPORTANCE

The bacterial colonization incidence related to IV catheter placement was slightly higher than the incidence described in other veterinary studies. Associated factors not previously described in veterinary medicine were found. The most frequently isolated organism was Acinetobacter spp., indicating its importance as an emerging pathogen in catheter colonization.

No evidence that medicinal honey reduces bacterial skin colonisation at a peripheral catheter insertion site in dogs

OBJECTIVES

To determine whether topical exit-site application of medicinal honey at the catheter insertion place reduces bacterial skin colonisation.

MEASUREMENTS AND RESULTS

Dogs were selected at random and divided into the honey or the control group. When the catheter was removed, an area of approximately 3×3 cm of the skin at the insertion site was sampled with a sterile cotton swab. The catheter stayed in place for a median of 84 hours. Out of 46 patients, 6 patients in the honey group and 5 out of 54 patients in the control group had a positive skin culture at the time of catheter removal (P=0·547). Infection was clinically suspected in 1 of those 11 dogs; catheter-associated complications were observed in 8 additional dogs that did not have a positive skin culture.

CLINICAL SIGNIFICANCE

Few catheter-associated complications were observed. Extra attention to hygiene by working with a standardised catheter placement and handling protocol might have resulted in this low incidence. In this study topical application of a medicinal honey did not reduce bacterial skin colonisation at the insertion site of peripheral catheters in dogs.

Extravasation reactions associated with the administration of pamidronate: 11 cases (2008-2013)

Pamidronate is a bisphosphonate drug widely utilized in veterinary oncologic practice for the palliation of malignant osteolysis. Pamidronate has not been previously reported to cause tissue injury upon extravasation in dogs. The medical records of 11 client-owned dogs undergoing palliative treatment for primary bone tumors with known or suspected pamidronate extravasation reactions were reviewed. The majority of adverse events were low grade in nature, however in some cases, the reactions were severe and led to euthanasia in one instance. Time to complete resolution of lesions ranged from within several days to greater than one and a half months. Aside from the dog that was euthanized, no long-term sequelae of extravasation were identified. Treatments employed to address the reactions varied widely. Pamidronate extravasation reaction appears to be an uncommon, but potentially serious complication of intravenous administration.

Using syndromic surveillance to estimate baseline rates for healthcare-associated infections in critical care units of small animal referral hospitals

BACKGROUND

Expected rates of healthcare-associated infections (HCAI) have not been established in veterinary hospitals. Baseline rates are critically needed as benchmarks for quality animal care.

OBJECTIVE

To estimate the occurrence of events related to HCAI identified using a standardized syndromic surveillance system in small animals in critical care cases at referral hospitals.

ANIMALS

Weaned dogs and cats (n = 1,951) that were hospitalized in the critical care unit of referral teaching hospitals during a 12-week period.

METHODS

Multicenter, prospective longitudinal study. A survey was completed for all enrolled animals to record basic demographics, information about procedures and treatments that animals received, and to document the occurrence of defined nosocomial syndromes. Data were analyzed to identify risk factors associated with the occurrence of these nosocomial syndromes.

RESULTS

Controlling for hospital of admission, 16.3% of dogs (95% confidence intervals [CI], 14.3-18.5) and 12% of cats (95% CI, 9.3-15.5) were reported to have had ≥ 1 nosocomial syndrome occur during hospitalization. Risk factors found to have a positive association with the development of a nosocomial syndrome were longer hospital stays, placement of a urinary catheter, surgical procedures being performed, and the administration of antiulcer medications and antimicrobial drugs excluding those given perioperatively.

CONCLUSIONS AND CLINICAL IMPORTANCE

Syndromic surveillance systems can be successfully standardized for use across multiple hospitals to effectively collect data pertinent to HCAI rates and risk factors for occurrence.

Resident Cats in Small Animal Veterinary Hospitals Carry Multi-Drug Resistant Enterococci and are Likely Involved in Cross-Contamination of the Hospital Environment

In the USA, small animal veterinary hospitals (SAVHs) commonly keep resident cats living permanently as pets within their facilities. Previously, multi-drug resistant (MDR) enterococci were found as a contaminant of multiple surfaces within such veterinary hospitals, and nosocomial infections are a concern. The objectives of this study were to determine whether resident cats carry MDR enterococci and to compare the feline isolates genotypically to those obtained from SAVH surfaces in a previous study. Enterococcal strains (n = 180) were isolated from the feces of six healthy resident cats from different SAVHs. The concentration of enterococci ranged from 1.1 × 10⁵ to 6.0 × 10⁸ CFU g⁻¹ of feces, and the population comprised Enterococcus hirae (38.3 ± 18.6%), E. faecium (35.0 ± 14.3%), E. faecalis (23.9 ± 11.0%), and E. avium (2.8 ± 2.2%). Testing of phenotypic resistance to 14 antimicrobial agents revealed multi-drug resistance (≥3 antimicrobials) in 48.9% of all enterococcal isolates with most frequent resistance to tetracycline (75.0%), erythromycin (50.0%), and rifampicin (36.1%). Vancomycin resistant E. faecalis (3.9%) with vanB not horizontally transferable in in vitro conjugation assays were detected from one cat. Genotyping with pulsed-field gel electrophoresis demonstrated a host-specific clonal population of MDR E. faecalis and E. faecium. Importantly, several feline isolates were genotypically identical or closely related to isolates from surfaces of cage door, thermometer, and stethoscope of the corresponding SAVHs. These data demonstrate that healthy resident cats at SAVHs carry MDR enterococci and likely contribute to contamination of the SAVH environment. Proper disposal and handling of fecal material and restricted movement of resident cats within the ward are recommended.

Bacterial and fungal colonisation of peripheral intravenous catheters in dogs and cats

OBJECTIVES

The purposes of this study were to determine the prevalence of intravenous catheter colonisation in a routine clinical setting, to identify pathogens involved and to explore factors associated with an increased risk of colonisation.

METHODS

A prospective study of 100 peripherally placed intravenous catheters from 13 cats and 78 dogs was conducted. The distal two-thirds were removed and submitted for bacterial and fungal cultures. Antimicrobial susceptibility of each isolate was determined.

RESULTS

Nineteen peripheral catheters were positive for microbiologic culture from 14 animals. Twenty organisms were isolated among which Staphylococcus species was the most common. Isolates displayed lower levels of resistance against the antimicrobial agents amoxicillin-clavulanate, cephalosporins and gentamicin than against other agents tested. Major risk factors predisposing to catheter-related colonisation included dextrose infusion, duration of catheter placement, local complications and immunosuppressive diseases or drugs.

CLINICAL SIGNIFICANCE

In a routine clinical setting, the prevalence of microbial colonisation of peripheral intravenous catheters is comparable to that found in an intensive care unit. However, consequences on morbidity and mortality rates differ.

Using 20-gauge percutaneous peripheral catheters to reliably collect serial 4-mL blood samples from conscious dogs

OBJECTIVE

To determine the reliability of collecting serial 4-mL blood samples over 13 h using a 20-gauge, cephalic catheter in conscious dogs.

DESIGN

Prospective, observational study.

ANIMALS

Twelve (6 males, 6 females) healthy, neutered, lean dogs.

PROCEDURE

Percutaneous placement of a 20-gauge, 1.1 x 30 mm intravenous over-the-needle catheter into the cephalic vein was performed in each dog on three occasions. Catheter patency was maintained by intermittent flushing with 0.9% saline and 1 IU/mL heparinised saline solutions. Blood samples (4 mL) were obtained at 10 time-points over 13 h, with close monitoring of the dogs and the indwelling catheters. Blood volume, resistance on aspirating blood sample (minimal or marked resistance) and the methods used to improve blood flow were recorded.

RESULTS

A high proportion (93%) of blood sample collections achieved the required 4-mL volume, and the remaining samples were greater than 1.5 mL. Of the 358 collections via the cephalic catheter, 311 (87%) were obtained with 'minimal resistance'. The remaining collections had 'marked resistance' (n=47) and were associated with a loose catheter in 11% (5/47) and of unknown cause in 89% (42/47). After 'marked resistance' had been encountered and the catheter was flushed with saline and heparin solutions, subsequent sampling with 'minimal resistance' was frequently possible from the same catheter.

CONCLUSION

Use of a percutaneous, 20-gauge intravenous cephalic catheter allowed reliable serial collection of 4-mL blood samples over 13 h in conscious dogs.

Prospective evaluation of complications associated with jugular venous catheter use in a veterinary hospital

OBJECTIVES

To prospectively investigate the incidence of mechanical and infectious complications associated with the use of jugular catheters and risk factors for these complications.

METHODS

Data was collected over a 6-month period and risk factors associated with the occurrence of mechanical or inflammatory complications were investigated.

RESULTS

One hundred catheters were placed over a 6-month period, totalling 393 catheter days. Complications were seen in 39% of catheters with a total of 51 complications. Forty-one of these complications were mechanical. A total of 10 inflammatory or infectious complications were identified in eight catheters (a total of 0.03 infectious complications per catheter day). Complications were more likely to occur in patients requiring more than one attempt for placement and patients that were ASA status 3 to 5. Infectious complications were more likely in patients not having general anaesthesia for placement, those having medical rather than surgical disease and those placed out of theatre. No association was found between the skill of the person placing the catheter and risk of complication.

CLINICAL SIGNIFICANCE

Mechanical complications are frequently associated with jugular catheter placement. Identification of risk factors for complications is important and warrants further study.

Staphylococcus-associated abortions in ewes with long-term central venous catheterization

Forty-two ewes had an intravenous catheter sewn in place in a prepared area over the jugular vein and beginning at 60 days of gestation received an infusion 3 times daily. The infusion consisted of sterile saline or sterile saline containing arginine. Twenty-six ewes in both control and treatment groups aborted between 81 days of gestation and term. Fetuses from 16 ewes that aborted were examined. Most were autolyzed or had early mummification. Macroscopic placentitis and noncollapsing lungs were noted. Large numbers of coagulase-positive Staphylococcus were isolated from fetal abomasal content, lungs, brains, or placentas. Histologically, suppurative placentitis with necrosis and pulmonary aspiration of meconium and amniotic debris often with suppurative bronchopneumonia were observed in abortuses. Four ewes euthanized and examined after abortion had suppurative endometritis. Three ewes had severe, chronic, jugular thrombophlebitis from which coagulase-positive Staphylococcus was isolated. The fourth ewe had mild phlebitis, and Staphylococcus aureus was isolated from both the catheter and the blood. Catheter-associated staphylococcal abortion was diagnosed.