Extended dwell and standard ultrasound guided peripheral intravenous catheters: Comparison of durability and reliability.

Background Vascular access is a critical component of emergency department (ED) care. Ultrasound guided placement of peripheral intravenous (USIV) catheters is increasingly common. However, USIV are thought to suffer from reduced durability and higher complication rates. Extended dwell catheters (EDC) are long peripheral IVs placed under combined ultrasound and wire guidance. The goal of this study is to compare dwell times and complication rates of EDC to standard peripheral USIV. Methods We performed a retrospective cohort study at a tertiary care adult ED comparing IV placements during a 17-month period (8/1/2018-12/31/2019), stratified by standard USIV versus EDC. The primary outcome was catheter dwell time and secondary outcomes included need for inpatient vascular access team (VAST) consultation, peripherally inserted central catheter (PICC) insertions, and radiocontrast extravasations. Multivariable Cox regression time-to-event analyses were used to evaluate dwell times, adjusting for age, gender, BMI and end-stage renal disease. Results 359 EDC and 4190 standard USIV were included for analysis. Most USIV (95.6%) and EDC (98.3%) were placed by ED technicians trained in ultrasound vascular access. EDC median dwell time (5.9 days [95%CI: 5.1-6.7]) exceeded standard USIV (3.8 days [95% CI: 3.6-4.0]). Patients with EDC placed in the ED required less VAST consultation (0.84 vs 0.99 charges/encounter), had similar rates of PICC line use (8.0% vs 8.4% of encounters) and had no radiocontrast extravasation events. Multivariable Cox regression demonstrated survival benefit (longer dwell time) favoring EDC (HR 0.70 [95%CI 0.60-0.81]). Conclusion Use of EDC results in longer dwell time and reduces subsequent use of vascular access resources, while maintaining low complication rates. EDC demonstrate superior durability which may justify their selection over standard USIV in some patients.

Attenuated muscle metaboreflex-induced increases in cardiac function in hypertension.

Sympathoactivation may be excessive during exercise in subjects with hypertension, leading to increased susceptibility to adverse cardiovascular events, including arrhythmias, infarction, stroke, and sudden cardiac death. The muscle metaboreflex is a powerful cardiovascular reflex capable of eliciting marked increases in sympathetic activity during exercise. We used conscious, chronically instrumented dogs trained to run on a motor-driven treadmill to investigate the effects of hypertension on the mechanisms of the muscle metaboreflex. Experiments were performed before and 30.9 ± 4.2 days after induction of hypertension, which was induced via partial, unilateral renal artery occlusion. After induction of hypertension, resting mean arterial pressure was significantly elevated from 98.2 ± 2.6 to 141.9 ± 7.4 mmHg. The hypertension was caused by elevated total peripheral resistance. Although cardiac output was not significantly different at rest or during exercise after induction of hypertension, the rise in cardiac output with muscle metaboreflex activation was significantly reduced in hypertension. Metaboreflex-induced increases in left ventricular function were also depressed. These attenuated cardiac responses caused a smaller metaboreflex-induced rise in mean arterial pressure. We conclude that the ability of the muscle metaboreflex to elicit increases in cardiac function is impaired in hypertension, which may contribute to exercise intolerance.