Intravenous Heparin Administration in Peripheral Venous Access: a practice based on the prevention of hemorrhagic events Administração de Heparina Intravenosa em Acesso Venoso Periférico: prática baseada na prevenção de eventos hemorrágicos

The aim of the study was to associate the occurrence and severity of hemorrhagic events with infusion devices used in anticoagulated patients with sodium heparin. It is a retrospective cohort study, performed by medical record analysis. Data collection took place in 2014 and 867 medical records of two intensive and one semi-intensive units of a public university hospital in Rio de Janeiro were investigated. The Bleeding Academic Research Consortium (BARC) scale was used to evaluate the hemorrhagic event severity, and to associate the hemorrhagic event occurrence with intravenous devices, the relative risk (RR) was calculated. In the study, the hemorrhagic event rate was 21.5% (CI = 13.5-31.5). Patients with peripheral venous access presented a 1.35 times greater risk of bleeding in the skin when compared to patients with central venous access. Patients with central venous access, already presented 1.29 times more risk of bleeding at puncture site when compared to patients with peripheral access. It is suggested that heparin is primarily infused with peripheral venous access, since the complications resulting from hemorrhagic events at the puncture site are more severe when compared to hemorrhagic skin events.


Introduction
The occurrence of hemorrhagic events in anticoagulated patients is of concern, because depending on their origin and the amount of blood involved, they may potentiate hemodynamic and ventilatory instability, increase mortality, length of stay in the intensive care unit, and require intervention measures (1) .
The occurrence of hemorrhage is a known risk of therapy with continuous infusion of sodium heparin. It is estimated that hemorrhagic events associated with the use of anticoagulants can occur anywhere in the body and range in frequency between 5.0% and 14.2% of patients who taking this medication (2)(3) .
In general, critically ill patients with continuous heparin infusion undergo multiple invasive procedures, including central or peripheral venipuncture for the infusion of the drug. Most invasive devices used in intensive care are inserted or handled by nurses on a daily basis.
In this sense, it is necessary that they seek solutions that can contribute to reducing the occurrence of hemorrhagic events related to heparin infusion, increasing safety and minimizing the negative impact on the patient, nursing team and institution (1)(2)(3)(4) . to reduce the occurrence of this event (4)(5) . (RR) was calculated, which is a measure of association between the occurrence of the disease in the exposed and non-exposed: values lower than one suggest exposure protection and values greater than one suggest a deleterious effect of exposure (6) . All RR calculations were made in 2x2 table, through the OpenEpi® software, which is available for free on the internet.
Fisher's exact test was used to calculate the relative risk for the analysis of classified data (nominal or ordinal), non-parametric, when the sizes of the two independent samples were small (7) . For all analyzes, a confidence level of 95% (p <0.05) was adopted.     (6)(7) .
The most common sites of hemorrhagic events were those located on the skin (47.37%), corresponding to hematoma and ecchymoses, followed by bleeding at the puncture site.
Hemorrhagic events in the skin were Most of these events are painless, when small.
However, when the amount of extravasated blood is greater, they can be painful and the symptoms will depend on the location (8) .  (9) .
When choosing for heparin infusion, the most common veins that are looked for in peripheral venous access are the veins of the back of the hand and the forearm, always giving preference primarily to the more distal sites. The veins located in the antecubital fossae are used less frequently, because they are the most calibrous and also the most troublesome, since they are located in the arm fold) (10)(11) .
If the option of infusion of heparin sodium occurs in central venous access, the most common sites of installation of these catheters are the subclavian and internal jugular veins, and may also be inserted into the basilic and femoral veins (10) .

Conclusion
This study suggests the use of sodium heparin in peripheral venous access because it is associated with bleeding events of smaller magnitude when compared to a central intravenous device.
Overall, regardless of the site of the bleeding, it has been found that there is a positive association between bleeding and intravenous devices. Thus, when it comes to infusing heparin, it is essential that nurses perform the procedures for patient safety and have autonomy to use it.
It is understood that the type of data presents itself as an inherent innovation in the technique of data collection, since the quality of the data depends on the quality of the records of the medical records. The size of the population is also presented as a limitation, because data were collected after two years of hospitalization, the number of patients receiving sodium heparin was reduced (n = 79), which may be justified because heparin is a potentially dangerous drug and its use is restricted to a small population with very specific indications.
However, it is noted that adverse events are rare, difficult to detect and in the analysis it is difficult to exercise control over the confounding factors. Therefore, it is understood that this type of study and these associations guide nursing care based on scientific evidence and suggest that nurses, with the aim of reducing the occurrence of hemorrhagic events, be cautious in manipulating central venous catheters in patients with sodium heparin.