The study aims to evaluate the rate of complications and the duration of cannulation of a midline intravenous catheter compared to a short peripheral catheter in patients hospitalized in an Internal Medicine service of a Spanish hospital.

A randomized, longitudinal experimental study is designed, which will allow comparisons to be made between the results obtained in the experimental group and the control group.

The study will be carried out in the Internal Medicine and medium and long stay unit of the CHGUV, during the period of time necessary to complete the required sample size, which has finally been established at six months.

When the patient is admitted to our unit, a number is assigned from the admission service, based on their admission order; this number will serve for subsequent random assignment to one another group. In this case, the use of a website to generate said numbers is proposed.

Using established procedures for the generation of random numbers, the numbers that correspond to the subjects that are going to be part of each of the groups will be identified.

The list of random numbers that will make up the experimental group has been prepared previously by the Internal Medicine Unit secretary and will be known by the person who will carry out the placement of the midline catheter (two nurses from the unit trained in the placement and handling of this type of device, who will also be those in charge of training the rest of the staff).

The list will be reviewed daily in the morning shift, and those patients who have not given their informed consent will be eliminated, those in whom, due to their pathology, a brief admission is expected or patients who are in a terminal or palliative care situation, in those who consider the step of treatment to the subcutaneous route as the best option.

The informed consent to participate in the study will be given to the patient and/or relatives at the time of admission, also informing them that the next morning those responsible for the study will explain the object of the study in more depth and answer their questions.

Before the third day after admission, in the morning shift, the peripheral catheters will be reviewed and replaced by another peripheral catheter or by a midline catheter depending on the group to which the patient has been assigned. In case of being a patient assigned to the experimental group, the midline catheter will be placed by personnel trained for it.

The procedures for inserting and maintaining the catheters are already established in the unit and will be those that will be followed during the study, depending on the type of catheter; The care in the insertion and maintenance of midline catheters does not differ from the care of peripherally inserted central catheters, since they require a sterile technique; therefore, although the insertion of the midline catheters will be done by the selected investigators, maintenance will be performed by the unit's staff, following, as we have indicated, the procedures already established.

When the patient requires a change of venous access for whatever reason, it will be replaced by the same type of catheter (midline or conventional catheter) and the necessary information will be added to the information record sheet.

Inclusion Criteria:

• The patients included were those who were hospitalized in the Internal Medicine Service of the Consorcio Hospital General Universitario de Valencia who needed intravenous therapy and who had signed the Informed Consent for placement of a midline at the time of the change of the PIVC placed in the emergency unit.

Exclusion Criteria:

• Those with a forecast hospitalization of less than one week, those who were receiving palliative or symptomatic treatment, those who were carriers of a CVC or those who had presented difficulty in venous access with midline after two consecutive attempts were excluded

Neither care providers nor patients could be masked because the intravenous device is different and it's easy to identify the one we are using.

Outcomes assessor only works with anonymized data