BACKGROUND A study was done with EMS personnel to determine the ease of use and acceptance of a saline lock (SL), intermittent infusion device in place of traditional intravenous tubing and fluid bags for prehospital intravenous (IV) maintenance. STUDY HYPOTHESES: Saline lock, intermittent infusion device use in specific clinical scenarios is easier, less expensive, and as effective as traditional IV tubing and fluid bags. The emergency medical technician-paramedic (EMT-P) would accept the implementation of saline locks in the emergency medical services (EMS) system. METHODS This was a prospective, non-blinded study with the EMS providers under the medical command of a suburban community hospital's emergency department. Patients were included if prophylactic IV access or medication administration was required by clinical protocols. Excluded from the study were those patients requiring IV access for fluid infusion, constant drug infusion, cardiac arrests, or transport to another hospital's emergency department (ED). Intravenous access was achieved with the usual catheter over needle cannulation techniques. The device (Interlink Injection Site SL) was attached to the hub of the IV cannula and flushed with 2 cc of 0.9% saline from prefilled carpujects. RESULTS There were completed questionnaires for 79 successful SL initiated in 98 attempts of IV access on 80 patients over a four-month period. When compared to traditional IV fluid bags, SL were judged by the paramedics to be less time-consuming to initiate and maintain (55 of 79 or 70%), easier to use (51 of 79 or 65%) and facilitated patient transportation (73 of 79 or 92%).(ABSTRACT TRUNCATED AT 250 WORDS)