RESEARCH ARTICLES

Characteristics of patients receiving sodium heparin: basing a safe care nursing

Flavia Giron Camerini^I; Lolita Dopico da Silva^II

ABSTRACT: Study aimed to characterize patients who received intravenous infusion of sodium heparin. Transversal study, retrospective, conducted from analyzing the records of patients who received continuous infusion of sodium heparin. 527 records were analyzed, of a sentinel hospital in Rio de Janeiro, in the years 2011 and 2012, in which 79 (14,99%) patients, received intravenous sodium heparin. Most patients had more than 60 years old, were distributed between diagnoses of Atrial Fibrillation, Acute Coronary Syndrome and Deep Vein Thrombosis. The median duration of therapy was four days. It was noted that the activated partial thromboplastin time, was dosed, on average, once a day and the rate of hemorrhagic events was 21.51%. It is concluded that during therapy with sodium heparin, nurses, to ensure safe care, should take into consideration the risk factors for bleeding and laboratory monitoring.

Keywords: Heparin; nursing; security; hemorrhage.

INTRODUCTION

According to the Institute for Healthcare Improvement (IHI), heparin sodium belongs to one of the ten categories of medicaments considered high risk or potentially dangerous medicaments (PDDs). These drugs are associated with the majority of adverse events in the hospital context¹;.

It is estimated that sodium heparin and other anticoagulants appear as one of the medicated groups most commonly involved in adverse events, ranging from 3 to 5.7% of the total adverse events with medicaments².

In the hospital environment, heparin sodium is widely used in critically ill patients. However, its use is associated with complications, such as: hemorrhages, hypersensitivity, tremors, headache, embolism, hyperkalemia, among others. Among the various complications, nursing should pay attention to the occurrence of hemorrhages, which constitute the main and most serious adverse event of heparin use³.

It is estimated that 5 to 10% of patients using sodium heparin have some kind of bleeding such as hematuria, high gastrointestinal hemorrhage, hemoptysis, epistaxis, ecchymosis, melenas and hematoma⁴.

Hemorrhagic events, such as complications of the use of continuous infusion of sodium heparin, worry, because according to the place or the affected organ and the volume of compromised blood can potentiate hemodynamic instability, ventilatory, increase mortality, length of hospitalization, besides requiring intervention⁵.

Sodium heparin is administered with controlled dose, and therapy dose adjustment requires knowledge by the nurse about minimum, maximum dose, toxic dose, stability and compatibility, and the ability to detect the main adverse events caused by this medical drug. In most institutions the nursing care related to continuous infusion of sodium heparin, resume to venous access control (peripheral or central), to the preparation and administration of the medical drug. Nurses have not incorporated into their routine, the identification of risk factors for hemorrhage, the monitoring of the activated Partial Thromboplastin Time (PTTa), the identification of therapeutic target of PTTa, the adjustment of the flow according to the weight and preventive conducts of hemorrhagic events⁵.

Despite the risk of hemorrhagic events in patients that use sodium heparin does not appear very high (5-10%), the nurse should consider the impact that this event has on prognosis. In this sense, it becomes necessary to look for solutions that can help to reduce their occurrence, minimizing the negative impact on the patient, the healthcare team and the institution^4,6.

By virtue of these facts, a survey was held that aimed to characterize patients who received intravenous infusion of sodium heparin to found the nursing care that increase patient safety.

LITERATURE REVIEW

Sodium heparin belongs to a family of sulfated mucopolysaccharides, heterogeneous, with chains of varying molecular weight. It shows extremely complex effects about the mechanism of coagulation, and anti-platelet effects. Its biological activity depends on endogenous anticoagulant, antithrombin. Its high affinity for antithrombin markedly inhibits blood coagulation by, mainly, the factors IIa and Xa of coagulation⁷.

It is a medicament that shows complex and conditioned pharmacokinetics to numerous variables. It is not absorbed from the gastrointestinal tract, its administration is intravenously or subcutaneously. It is known that medicaments administered intravenously have fast action and have a higher potential for damage and sometimes irreversible⁷.

Of the adverse events of pharmaco-vigilance interest of the heparin use, the heparin-induced adverse reactions are emphasized, including hemorrhage, anaphylactic reaction, elevated liver enzymes, osteoporosis (with long-term use), alopecia, and hypoadrenalism and thrombocytopenia induced by heparin.

On these events, the occurrence of hemorrhage is emphasized by the frequency and severity. The hemorrhages can generally be classified into four classes according to the volume of blood lost, being hemorrhage class I the slightest and class IV, more severe⁸.

METHODOLOGY

Transversal study, retrospective, conducted from documentary analysis of medical records of patients who received continuous infusion of sodium heparin.

The researched variables were: the number of PTTa measured; duration of therapy with sodium heparin infusion (days); days of hospitalization; occurrence of bleeding; previous use of anticoagulant; sex; age; weight; diagnosis (indicative of the use of sodium heparin); via of administration of sodium heparin; in addition to the presence of risk factors, such as renal and hepatic insufficiency; hypertension (HAS).

To identify the variables in the records of patients, the clinical evolutions were used, the sheets of water balance and medical prescription, as well as data identifying the patient.

The records were of inpatients at intermediate unit (IU) and coronary care unit (CCU) of a large hospital, located in the municipality of Rio de Janeiro, belonging to the Sentinel Network. The sample calculation was dismissed, opting for investigating all records between the years 2011 and 2012 of all patients admitted to the UI and CCU. The population consisted of medical records of all patients that, in the study period, made use of continuous infusion of sodium heparin and met the criteria of IHI with regard to potentially dangerous medicaments, namely: full admission record and discharge; period greater than 48 hours of hospitalization; pregnant women excluded and children under 18 years.

The technique of data collection was document analysis, which is based on original documents, which did not received analytic treatment and are considered primary sources. The research was approved by the Ethics and Research Committee (ERC) under the number 3082/2011.

Data were organized in its own database, using Microsoft ® Excel 2010 program, submitted to descriptive statistics, and measures of central tendency were calculated.

RESULTS AND DISCUSSION

The tracking of 527 records have revealed that 87 (16.51%) patients received sodium heparin by continuous infusion. However, occurred the loss of eight records. Therefore, the study population comprised 79 (14.99%) records of patients, who received sodium heparin by continuous infusion in 2011 and 2012.

As sodium heparin has indications well described in the literature, it was chosen to group patients according to diagnosis, as shown in Table 1.

Among the 79 (14.99%) patients who were treated with sodium heparin, it was found that 37 (46.25%) were diagnosed with Atrial Fibrillation (AF), followed by 22 (27.85%) patients with Acute Coronary Syndrome (ACS) and 20 (25.32%) with Deep Vein Thrombosis (DVT).

Among patients with AF, women predominated, 23 (62.16%), which had the lowest median hospitalization - 13 days, made use of sodium heparin for 3 days and have as main risk factor for bleeding the age over 60 years old.

Among patients with ACS, men predominated, 13 (59.09%), aged over 60 years old, 17 (77.27%) who used heparin for 4 days and present as main risk factor for bleeding the hypertension - 15 (68.18%).

Among patients diagnosed with DVT, women predominated - 14 (70%), with a longer infusion with sodium heparin (Md=5days), and the main risk factors for bleeding were associated with the presence of hypertension in 12 (60%) and age over 60 years old - 13 (65%).

In general, there was a predominance of elderly patients - 52 (65.82%), female - 46 (58.23%) with a median of 17 days of hospitalization (Md=17.75), prevalence of peripheral venous access - 57 (72.15%). It is noted also that most already used anticoagulant of other type - 45 (56.96%).

In 79 patients who used sodium heparin in continuous infusion, were measured in all 375 PTTa with a median of 5 PTTa per patient and 5 days in duration of heparin therapy.

Of all patients who used sodium heparin in continuous infusion 17 (21.51%) had some type of bleeding, mainly hematuria, hematoma and epistaxis. Most patients who developed hemorrhage were elderly (Md=63 years), predominantly female (58.82%) and peripheral venous access (64.71%).

Among patients with any type of bleeding, those with diagnoses of AF were prevalent. Patients with ACS reported a longer hospitalization (Md=21 days), followed by patients with AF (Md=18 days). Patients with DVT had a higher body weight (Md=86 kg). The duration of infusion therapy with sodium heparin was higher in patients with DVT (Md=5 days), and the number of PTTa measured during this period had a median of 6. Among the patients with AF, the duration of therapy was 4 days, with Mid 6 for measured PTTa. It is noted also that most patients have had prior use of another type of anticoagulant - 11 (64.71%), as shown in TABLE 2.

INSERT TABLE 2 HERE

The discussion will be developed based on the main findings - the diagnoses that indicated the use of heparin, the risk factors for the occurrence of hemorrhage, monitoring of PTTa and specific care related to heparin.

Clinical Diagnoses

Most patients who used intravenous heparin had as clinical diagnosis the presence FA, which is the most common arrhythmia in clinical practice, and has a high prevalence and is estimated to be present in 1% of the general population. The indication of heparin for the treatment of AF is based on the fact that anti-coagulated patients are highly benefited with reduced rates of thromboembolic events, arising from the FA thus reducing mortality⁹.

It was found that most patients with AF, 59.46% were older than 60, which corroborates the literature describing the incidence of AF increased significantly with advancing age. It is estimated that AF achieves up to 10% of patients over 80 years old, being currently the fifth leading cause of hospitalization in the Unified Health System(UHS)⁹.

Currently there are some scales that quantify the risk of patients hemorrhage, according to the pathologies. Hypertension, Abnormal renal/liver function, Stroke, Bleeding history or predisposition, Labile INR, Elderly, Drugs concomitantly (HAS-BLED) is a scale that quantifies the hemorrhagic risk in patients with AF, it was proposed in 2010 and is recommended by most recent European guidelines¹⁰.

The HAS-BLED is presented as a practical tool for assessing the risk of bleeding in patients with AF who are on anticoagulant prophylactic therapy, using variables such as: Hypertension; Renal and Hepatic Insufficiencies; history of Cerebrovascular Accident (CVA); Hemorrhagic predisposition; International Values Normalized Ratio (INR) high (≥4) or unstable; Age greater than 65 and if the patient is alcoholic or make use of other medicaments that affect coagulation. This scale considers that the patient is at low risk if the score is less than three and a high risk if the score is greater than three. Therefore, the HAS-BLED is a prediction model for the occurrence of hemorrhagic risk and can help nurses to identify patients with AF who have a higher risk of hemorrhage¹⁰.

The presence of ACS was the second most common diagnosis. The effectiveness of the use of sodium heparin in ACS is proven in several studies, such as was held the meta-analysis11 of six clinical trials and showed that sodium heparin causes a strong trend to reduced rates of re-infarction and recurrent ischemia, when the goal of PTTa is 1.5 to 2.0 times control.

We have that 13 (59.09%) ACS patients who received sodium heparin were male. Similar studies in the literature also identified a prevalence of males among patients with SCA¹².

Age is also described in the literature as a risk factor for developing SCA. It was found that 17 (77.27%) patients with ACS were older than 60 years old. It is estimated that the risk of SCA increases progressively after each decade over the age of 40 years old¹².

For ACS patients, was found no scale that quantifies the risk for bleeding. However, there are scales that quantify the bleeding, such as the classification of the Global Utilization of Strategies To Open occluded arterie (GUSTO), which divides the bleeding events in mild, moderate and severe¹⁴.

Besides the FA and SCA, some patients using sodium heparin had DVT as clinical diagnosis. Deep vein thrombosis, despite having been diagnosed less frequently among patients in this study, is a disease of high incidence and serious health problem with high morbidity.

Patients with DVT who used sodium heparin, 7 (35%) were younger than 60 years old, which shows that DVT is a condition that affects from younger patients, without previous diseases, to  older.

Anticoagulation with sodium heparin is the mainstay of treatment of DVT and should be instituted as soon as possible, because the more rapid and effective treatment of the acute phase, the lower the chances of late sequelae. Therefore, it is known that the gold standard for treatment of DVT is anticoagulation, and that this form of treatment aims to relieve the acute symptoms, and prevent the occurrence of pulmonary thromboembolism.

It is noteworthy that was not found in the literature any risk scale that quantifies bleeding or bleeding, directed to patients with DVT.

It is known that the treatment of these comorbidities the use of sodium heparin has risks, it is complicated and expensive and therefore the recommendation of the nurse to monitor it carefully¹⁵. Accordingly, it is understood that by identifying the hemorrhagic risk according with pathology, can improve the use of anticoagulation therapy. In addition, the risk classification scales allow nurses to identify patients in whom the benefits of anticoagulation outweigh the risks.

Risk factors for the occurrence of hemorrhage

Among the many risk factors described in the literature, it was found in this research to older than 60 years old - 52 (65.82%), hypertension - 44 (55.70%), renal failure - 18 (22, 78%) and liver failure - 5 (6.33%).

Elderly patients with greater than 60 years, are classified as risk group due to the high sensitivity, they have lower iron absorption due to age, showed a smaller amount of body fluid and a lot makes regular use of anti-platelets. Thus, appear as a population with higher risk of hemorrhagic complications¹⁶.

The presence of hypertension is also a non-modifiable risk factor for the occurrence of hemorrhage, the higher the blood pressure, the greater the risk of an hemorrhagic event. The pressure exerted on the vessels related to the use of anticoagulant, may increase considerably the occurrence of bleeding¹⁷.

Renal failure is also a risk factor for bleeding in patients using sodium heparin, as it has renal elimination and the presence of renal failure can also prolong the anticoagulant effect of heparin. Therefore, patients with renal failure have an increased risk of hemorrhagic complications¹⁸.

Regarding the presence of liver failure, it is known that 25% of the metabolism of sodium heparin is liver, so the presence of liver failure may endanger metabolism of heparin and increase the hemorrhage risk. According to a study, un-fractionated heparin has a relationship with asymptomatic elevation of transaminases and it was proven that the majority of patients using heparin showed laboratory abnormalities in liver function¹⁹.

Due to the multifactorial nature of the occurrence of hemorrhages, knowledge of risk factors is critical to the adoption of preventive and therapeutic measures, which are described below.

Monitoring of PTTa

The duration of therapy with sodium heparin in continuous infusion had a median of 4.25 days, which agrees with the literature, which does not indicate the use of sodium heparin for more than 5 days, due to the increase in adverse events, especially Heparin Induced Thrombocytopenia (HIT)²⁰.

The PTTa is the test used to evaluate all the factors of the intrinsic coagulation via (except platelets) by determining the time required for the formation of a fibrin thrombus in a plasma sample. According to some authors, is the most appropriate test to monitor response to treatment with sodium heparin²¹.

In the present study, the number of PTTa dosed showed a median of 4.25, which showed that on average was applied one PTTa daily (every 24 hours). Monitoring the use of intravenous heparin noteworthy because it is a potentially dangerous medicament and widely applied. According to the literature, the PTTa should be harvested every 8 hours, three times in 24 hours²².

When indicated the anticoagulation with sodium heparin, the ideal level corresponds to an activated partial thromboplastin time 1.5 to 2.0 times the normal value, which is 21-35 seconds,that is  between 60 and 80 seconds approximately. There are several protocols for systemic heparinization; they differ in initial administered doses, in the control of anticoagulation, in the time for the administration of booster doses and neutralization by protamine. In general, protocols that indicate  the lower doses, include tighter control of anticoagulation.

The control infusion and of PTTa is the most decisive factor error in heparin. According to a conducted study, it was evident the superiority of the administration of heparin by algorithm controlled by nursing. The same study showed that the advantages of using an algorithm to control heparin are: less time spent and fewer interventions to reach the ideal level of heparinization; plus a greater flexibility to correct excessive or insufficient anticoagulation⁶.

Specifics of care to patients using sodium heparin

The results showed that 57 (72.15%) patients received sodium heparin for peripheral venous access. Heparin is a medicament that has a pH of 5 to 8, so it can be administered by both central and peripheral access. However, the literature indicates that sodium heparin, can be a medicament of high risk, should be administrated in exclusive access and in infusion pump to ensure the control of the infusion velocity²³.

The infusion of sodium heparin via an intravenous, increases the risk of bleeding from the puncture site, therefore the nurse must perform some specific care to the prevention of this undesirable event related to the use of sodium heparin. Thus, it is understood that the most suitable vein for infusion of sodium heparin are the most caliber.

A safe nursing care to patients using sodium heparin in continuous infusion, must aim to detect early signs and symptoms of bleeding or intravascular volume deficit; minimize blood loss and to restore intravascular volume; prevent bleeding episodes and detect decreased tissue perfusion. In front of the risk of hemorrhages due to the use of sodium heparin, the nurse should assess in the physical examination, the general condition of the patient, to see color of mucous membranes, hydration, pulse, blood pressure, respiratory frequency and level of anxiety.

The occurrence of hemorrhagic events in this study reached 17 (21.51%) patients. This rate is higher compared to other studies, which showed 3%² rate and rate 5-10%4, related to hemorrhagic events from the use of sodium heparin.

The occurrence of hemorrhage, in addition to reduce the potential benefit of anticoagulation, increases the fear of iatrogenic hemorrhage, causing reduction in the use of anticoagulants in patients with indication for this therapy.

It is noteworthy that regardless of the frequency of the event is known that therapy with sodium heparin is always accompanied by the risk of hemorrhage, which may have prognostic implications and may even lead to increased mortality²⁴.

Therefore, since for healthcare institutions the most important aspect when it comes to security is not harmful for the patient during the treatment²⁵. It should prioritize one nursing care to patients using sodium heparin, aimed at the prevention of hemorrhages.

CONCLUSION

The studied patients who received heparin in the hospital are predominantly elderly, with more than 60 years old, were mainly distributed between the diagnosis of AF, ACS and DVT. Most patients received heparin for peripheral access and presented a median infusion time of 5 days.

The most prevalent risk factors for the occurrence of bleeding are older than 60 years old, followed by the presence of hypertension. Is noted also that more than half of the patients were using another type of anticoagulants.

The rate of hemorrhagic event in patients receiving sodium heparin in continuous infusion reached 21.51%, slightly higher compared to the rates reported in the literature.

To ensure the best effect of sodium heparin and reduce the hemorrhagic risk, appropriate tools to stratify the risk should be used, in addition to conducting a careful and effective laboratory monitoring. In this sense, the nurse role in attention to these risk factors and near to the patient is crucial to improve safety.

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