Single Lumen Midline Catheter vs Ultrasound Guided Peripheral IV as Performed by Bedside Emergency Department Registered Nurses

Inclusion Criteria: * Adults 18 years of age or older * Presenting to the Albany Medical Center Emergency Department * Require intravenous access * Have difficult intravenous access (DIVA) defined by at least one of the following: * Two failed attempts at landmark-based or ultrasound-guided peripheral vascular access performed by qualified emergency department staff * A history of or active comorbid condition associated with difficult intravenous access, including: * Implanted vascular access port (current or previous) * End-stage renal disease with dialysis fistula * Sickle cell disease * Current or previous intravenous drug use * Self-reported difficult intravenous access plus one of the following: * A history of requiring two or more IV attempts during a previous healthcare encounter (self-reported or documented in the medical record) * A previous requirement for a rescue vascular access device after failed IV access, including: * Ultrasound-guided peripheral IV * Midline catheter * Peripherally inserted central catheter (PICC) * Central venous catheter (CVC) * Intraosseous catheter Exclusion Criteria: * Younger than 18 years of age * Prisoners * Non-English-proficient patients * Patients in whom the device cannot be adequately stabilized because of tissue injury or treatment involving the available extremities (including burns, complex humeral fractures, or dialysis fistulas) * Patients who lack the capacity to provide informed consent and do not have an authorized legal representative available * Patients without an identifiable target vein on ultrasonography * Patients known to be pregnant * Previous enrollment in the study * Previous withdrawal from the study * Presentation during a period when no study proceduralists are available * Patients for whom the informed consent and enrollment process could delay time-sensitive medical care