Air embolism following removal of hemodialysis catheter

Evaluation of the Catheter Clamp over Hydrophilic Guide Wire Central Venous Catheter Exchange Technique for Air Embolism Prophylaxis in an In Vitro Model

PURPOSE

To develop a reproducible in vitro model simulating central venous catheter (CVC) exchange with high potential for air embolization and test the hypothesis that a closed catheter clamp over hydrophilic guide wire exchange technique will significantly reduce the volume of air introduced during CVC exchange.

MATERIALS AND METHODS

The model consisted of a 16-F valved sheath, 240-mL container, and pressure transducer submerged in water in a 1,200-mL suction canister system. Continuous wall suction was applied to the canister to maintain negative pressure at -7 mm Hg or -11 mm Hg. Each trial consisted of 0.035-inch hydrophilic guide wire introduction, over-the-wire catheter exchange, and wire removal following clinical protocol. A total of 256 trials were performed, 128 trials at each pressure with the catheter clamp open (n = 64) or closed (n = 64) around the hydrophilic guide wire.

RESULTS

There was a statistically significant lower volume of air introduced with closed clamp over-the-wire exchanges than with open clamp exchanges at both pressures (2-tailed t-test, P < .001). At -7 mm Hg, a mean of 48.0 mL (SD ± 9.3) of air was introduced with open clamp and 20.6 mL (SD ± 4.7) of air was introduced with closed clamp. At -11 mm Hg, 97.8 mL (SD ± 11.9) of air was introduced with open clamp and 37.8 mL (SD ± 6.3) of air was introduced with closed clamp.

CONCLUSIONS

This study demonstrated the use of a reproducible in vitro model mimicking conditions causing air embolism during CVC exchange. Results showed that CVC exchange using closed catheter clamp over hydrophilic guide wire exchange technique significantly reduced the volume of air introduced per exchange.

Hemodialysis Catheters: Update on Types, Outcomes, Designs and Complications

Hemodialysis catheters (HDCs) are an essential part of kidney replacement therapy. While these catheters are considered only the bridge to long-term vascular access such as arteriovenous fistulas and grafts, they are associated with significant morbidity and mortality and subsequent increased health care expenditures. However, despite these risks, a large proportion of end stage kidney disease population initiates dialysis using these catheters. The pathogenicity of HDCs stems from its invasive nature to the venous vasculature tree resulting in both mechanical and infectious complications. Therefore, the wide use these catheters in dialysis population and the associated complications necessitated continuous innovations in the catheter material, design, and placement techniques. This review provides an update on the catheter types, catheter tip designs, and the new technologies and innovations aimed to improve the catheter functionality and mitigate its related complications.

Educational value of Internet videos in vascular access

Aim:

The aim of the study was to evaluate individually uploaded Internet materials about catheter insertion and removal in terms of their educative value.

Methods:

YouTube videos for both catheter insertion and catheter removal were investigated. Rating, like, dislike, the position of a patient, maneuvers during removal, immediate coverage of removal site, and type of cover material were noted. A survey regarding daily practices for catheter interventions and approaches to educative social media platforms had been taken from medical professionals as well to determine the effect of social media on learning practices.

Results:

A total of 50 insertion and 35 removal videos were investigated. The popularity of insertion and removal videos was 4.7 (1.6–16.5) and 1.88 (0.66–4.54), respectively. ( p = 0.011). The position of a patient during insertion was supine in 80%, Trendelenburg in 18%, and upright in 82.9% of the removal videos ( p = 0.000). The survey showed that medical professionals watched insertion videos (66%) more than removal videos (11.7%) ( p = 0.002). Catheter insertion positions were similar among participants ( p = 0.553). Removal positions were different in specialties ( p = 0.023) in which especially nephrologists tend to remove the catheter at the sitting position.

Conclusion:

Medical professionals think that removal is an easier procedure than insertion. They both search more for insertion videos and upload more insertion videos. Insertion practices are similar among different specialties. However, removal practices are more heterogeneous. Individually uploaded catheter videos at YouTube are not reliable educative materials. More free official work should be produced to maintain sufficient qualified online material on social media platforms.

Cortical Blindness and Altered Mental Status following Routine Hemodialysis, a Case of Iatrogenic Cerebral Air Embolism

Cerebral air embolism is a known complication from a myriad of iatrogenic causes. This case describes a 60-year-old female presenting from hemodialysis with altered mental status, bilateral homonymous hemianopia, and repetitive speech. A noncontrast head CT revealed air in the vein of Galen and the deep cerebral veins of the left thalamus and occipital sulcus, a complication from air being introduced into the patient via improper flushing of dialysis tubing. The retrograde flow of air bubbles in the upright patient during dialysis was likely responsible for the air embolus lodging in the cerebral vasculature. This patient was transferred to receive hyperbaric therapy, whereupon the patient survived with residual attention and spatial deficits.

Venous air embolism related to the use of central catheters revisited: with emphasis on dialysis catheters

Venous air embolism is a dreaded condition particularly relevant to the field of nephrology. In the face of a favourable, air-to-blood pressure gradient and an abnormal communication between the atmosphere and the veins, air entrance into the circulation is common and can bring about venous air embolism. These air emboli can migrate to different areas through three major routes: pulmonary circulation, paradoxical embolism and retrograde ascension to the cerebral venous system. The frequent undesirable outcome of this disease entity, despite timely and aggressive treatment, signifies the importance of understanding the underlying pathophysiological mechanism and of the implementation of various preventive measures. The not-that-uncommon occurrence of venous air embolism, often precipitated by improper patient positioning during cervical catheter procedures, suggests that awareness of this procedure-related complication among health care workers is not universal. This review aims to update the pathophysiology of venous air embolism and to emphasize the importance of observing the necessary precautionary measures during central catheter use in hopes of eliminating this unfortunate but easily avoidable mishap in nephrology practice.