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Revista Latino-Americana de Enfermagem

On-line version ISSN 1518-8345

Rev. Latino-Am. Enfermagem vol.19 no.5 Ribeirão Preto Sept./Oct. 2011 



Randomized clinical trial to assess pain and bruising in medicines administered by means of subcutaneous and intramuscular needle injection: Is it necessary to have needles changed?



Luiz Carlos Ribeiro LambletI; Edilson Sant'Anna MeiraII; Silvana TorresIII; Barbara Carvalho FerreiraIV; Sergio Dias MartucchiV

IRN, M.Sc. in Health Sciences, Conselho Regional de Enfermagem de São Paulo (COREN-SP), Brazil. E-mail:
IIRN, Laboratório Central, Hospital São Paulo, Universidade Federal de São Paulo, Brazil. E-mail:
IIIRN, Specialist in Infection Control Hospital Management, ATE – Assessoria e Treinamento em Enfermagem, SP, Brazil. E-mail:
IVRN, Specialist in Infection Control Hospital, Biodina SP Representações S/C Ltda, São Paulo, SP, Brazil. E-mail:
VRN, Specialist in Care to Severe and Politraumatized Patients. Hospital Municipal Dr. Moyses Deutsch M'Boi Mirim, São Paulo, SP, Brazil. E-mail:

Corresponding Author




This clinical trial aimed at comparing the intensity of pain and bruising by subcutaneous and intramuscular injections using and retractable fixed syringes and needles and syringes with no needles combined, at a public hospital in Sao Paulo, for six months. We evaluated the perception of pain in case of intramuscular (n=1000) and subcutaneous injections (n=240). In subcutaneous application, bruise formation was also verified. Pain and bruising scores were higher in the group with no needles combined (p<0.001) and (p<0.029), respectively. The test power in relation to the pain scale of was 0.98. The use of retractable fixed needles is recommended in the application of subcutaneous and intramuscular injections. Clinical trial registration number: NCT01271608.

Descriptors: Pain; Hematoma; Needlestick Injuries; Injections Intramuscular; Injections Subcutaneous; Injections Intradermal; Accident Prevention; Protective Devices.




The World Health Organization (WHO) recommends the use of safety devices for intramuscular, subcutaneous and intradermal medication administration. These devices avoid equipment reuse and health professionals' contact with piercing and cutting material like needles, which increase the risk of biological accidents(1).

Between two and three million percutaneous accidents involving needles contaminated with biological material occur every year(2-3). A North American study showed that health professionals are exposed to between 385,000 and 800,000 piercing and cutting accidents per year, involving risks of transmitting blood-borne pathogens like hepatitis B, C and HIV, among others(4). The impact of these accidents includes emotional damage, decreased productivity at work and financial impacts for the health system(5). Between 1995 and 2003, the National Surveillance System for Health Care Workers (NaSH) demonstrated that 26% of piercing and cutting accidents are associated with needle manipulation in patients (2,662/10,239) and 5% with needle recapping (512/10,239). Six devices are responsible for 80% of injuries, 56% involving hollow needles and 30% hypodermal needles (5,612/18,708). Sixty-four percent of piercing and cutting accidents could be avoided. The Centers for Disease Control and Prevention (CDC) recommends that institutions establish a program to enhance a safety culture that includes the assessment of new safety devices for health professionals(6).

A systematic review on the occurrence of occupational infection by HIV in health workers in Brazil showed that the four identified cases involved nursing professionals and that contamination was due to percutaneous exposure(7).

A study on accidents involving piercing and cutting material among nursing workers, between 1985 and 2000, which analyzed 39 international and 16 Brazilian studies, appointed that the main factors associated with piercing and cutting accidents were needle handling and recapping(8).

A study conducted at a tertiary hospital between July 2003 and July 2004, involving 200 cases and 200 controls, which assessed the factors associated with percutaneous accidents in the nursing team, showed that one of the predictors was needle recapping (OR 9.48; CI 95%)(9).

In São Paulo State, Brazil, the Biological Accident Notification System (SINABIO) was created as from 1999. Out of 14,096 accidents notified until 2006 in approximately 20% of cities in the State, it was evidenced that 85.5% were percutaneous, 57.7% involved nursing professionals and 4.2% were due to needle recapping(10).

In Brazil, in 2005, Ministry of Health Decree 485 was approved, which sets standards for occupational safety and health in health establishments – NR-32(11). This Decree established a deadline to implant safety devices for all piercing and cutting material(12). Implanting safety devices demands tests to assess their efficacy and adequacy to their goals. Engineering of these devices should permit easy handling, passive activation and minimal changes in the usage technique(1-2,4,6).

In Brazil, intramuscular, intradermal and subcutaneous drug administration is performed, involving the exchange of the needle through which the substance is aspirated to apply the drug. These recommendations are mentioned in different technical books and are based on established practices, but are not accompanied by scientific evidence(13-15). Most drug administration manuals do not address the need to change needles in order to apply injections(16-17).

In a literature review carried out LILACS and Medline, Pubmed and a dissertation and thesis bank, using the descriptors: "pain", "hematoma" "exchange", "intradermal injections", "subcutaneous injections", "intramuscular injections" combined with "methods", "adverse events", "prevention" and "control", studies on the theme were identified.

One study recommends changing needles after aspiring the drug to guarantee cleanliness, needle cutting, adequate caliber and length, thus avoiding pain and contact between the drug and subcutaneous tissue(18).

Other studies also recommend changing needles for injection application as good practice. These recommendations propose that, in certain situations, one should clean the needles with sterile gauze or transfer the drug to another sterile syringe before its administration(19-20). Nevertheless, risks of contaminating the drug and equipment and accidents involving piercing and cutting material should be taken into account.

The Brazilian Diabetes Society recommends insulin preparation and application using needles combined with syringes. When administering two types of insulin, the use of needles not combined with syringes is recommended, so as to guarantee the aspiration of the correct dose(21). The CDC does not recommend changing needles when applying vaccines(22).

Three studies cited below assessed pain or bruising, comparing the drug administration technique with or without needle changing.

The study that compared insulin administration with and without needle changing demonstrated that the diameter of the bruise did not decrease when changing needles (p=0.87)(23).

The trial that involved patients (n=70) who received intramuscular viscous drugs through two techniques, with and without needle changing, demonstrated results without differences in pain intensity levels measured on the numerical scale in both groups (p<0.05)(24).

The randomized trial that compared two groups of pediatric patients between six months and six years of age who were receiving the same volume of a double vaccination (tetanus-diphtheria) from the same laboratory through the intramuscular route was conducted during eight weeks. The same technique was used for the application, with or without needle change. In that study, 423 patients participated and 346 forms were returned (81.8%). No statistically significant differences were found in bruising levels, hardening of the site or edema in the two compared groups. Likewise, no statistically significant difference was observed in systemic effects either, including fever, vomiting, appetite loss and crying(25).

Needle changing for injection administration is a widespread practice among health professionals, without any scientific foundations. Today, syringes with retractable fixed needles are available to protect health professionals. In view of industrial and technological advances in health equipment manufacturing, research is needed on whether needle changing effectively prevents pain and bruising in case of intramuscular or subcutaneous injection administration.



To compare pain intensity using the numerical scale (0 to 10), in case of intramuscular injection and subcutaneous injection, applying retractable fixed needle syringes and the technique with needle switching;

To compare bruising after subcutaneous insulin administration, using retractable fixed needle syringes and the technique with needle switching.



This randomized clinical trial was accomplished at two medical-surgical units – one medical-surgical hospitalization Unit and one Emergency Care Unit of a hospital in São Paulo City, between June 15th and November 30th 2009, after obtaining approval from the Institutional Review Board (CAAE - 0203.0.028.000-08).

The population comprised patients who were sequentially included in the study through a draft system, in which random figures in sealed and dark envelopes were used.

Sample design and size

Subcutaneous injection: the sample size was based on the expected proportion of bruising after the injection. It was expected that 40% of patients would present bruises as a result of the conventional technique and 20% when using the technique under analysis for subcutaneous applications. Setting a 5% alpha error (p=0.05) and 80% study power (20% or 0.2 beta error), 240 patients were included, 120 in each group.

Intramuscular injection: the sample size was based on the proportion of patients with moderate to intense pain. The habitual incidence level of moderate to intense pain was considered at 30% in case of needle switching, as well as an increase of up to 40% when using the retractable fixed needle syringe. Five hundred patients were included in each group.

The sample for intramuscular injection comprised 1,000 patients, 500 for each technique, and that for subcutaneous injection 240 patients, 120 for each technique.

Patients over 18 years old who agreed to participate in the study were included at one single time for the subcutaneous and intramuscular injections. The monitoring took place after reading, verifying the understanding and signing the Free and Informed Consent Term. Patients using anticoagulants or with coagulation disorders, lesions or cutaneous alterations were excluded. In the intervention group, the technique with retractable fixed needles was used to administer intramuscular and subcutaneous injections. In the control group, the conventional medication administration technique was used.

The nursing teams at both medical-surgical units were submitted to a seven-day training program on the intramuscular and subcutaneous injection application technique using retractable fixed needle syringes and the conventional technique. A nurse was exclusively hired for this function. An assessment form and the adapted numerical scale for pain assessment were used as data collection instruments(26). On the assessment form, all study variables of interest (initials, gender, age, baseline disease, hospitalization date, medication use, body mass index, bruise size, application site, drug name and administered volume) were registered. For those patients who received the subcutaneous injections, the bruise size in millimeters was included, when present. The body mass index was verified through the following formula: weight in kilos /(height in meters)(2).

After the patient's consent, the assessment form was completed, taken from a sealed envelope, which the professional opened, after which (s)he applied the intramuscular or subcutaneous injection, using the conventional technique or retractable fixed syringe, according to the randomization. After the injection application, the patient was shown a numerical scale ranging from 0 to 10 in order to score the pain the injection application had caused. In the subcutaneous injection group, after 24 hours, the nurse measured bruise size with a millimeter ruler. Patients were included in the study until completing the necessary sample size.

Syringes and needles used

Conventional technique: for the intramuscular injection, a 5-milliliter syringe was used. After aspiring the drug with an 18G x 1.5" (40 x 1.2 mm) needle, it was disconnected from the syringe, after which a 22G x 1¼" (30 x 0.7 mm) needle was connected for the application. For the subcutaneous injection, a 1-milliliter syringe was used with 100 UI, connected with a fixed 26G x 0.5" (13 x 0.45 mm) needle.

Retractable needle technique: for the intramuscular injection, a 5-milliliter syringe was used with a retractable fixed 22G x 1½" (0.7 mm x 38 mm) needle. For the subcutaneous injection, a 1-milliliter syringe was used with 100 UI, connected with a retractable fixed 27G x ½" (0.4 x 12.7 mm) needle.

Injection application technique

Subcutaneous injection: the administered drug was insulin, according to the units prescribed to the patient. The application site was determined using an instrument to assess the body area turnover used for insulin application to patients, included in their files.

After determining the application site and performing skin antisepsis, the cutaneous fold was fixed with the non-dominant hand and the needle was introduced at a 90º angle. Without aspiration, the insulin was injected. In the conventional technique, the needle was rapidly withdrawn and the application site was slightly compressed with a swab without massaging. In the retractable needle technique, the same procedure was performed but, at the end of the application and full compression of the vial, the retractable device introduced the needle inside the body of the syringe before its removal from the subcutaneous tissue.

Intramuscular injection: the injected drugs were prescribed for the patient's treatment. The volume ranged from 1 to 4 ml. Intramuscular injections applied in the dorsal-gluteal region were assessed, as that was the body region professionals who administered medication at the Emergency Care commonly used at the institution for this type of procedure.

The gluteal region was divided in four parts and the injection was applied in the external upper quadrant. After skin antisepsis, the needle was introduced at a 90º angle. After applying the injection and removing the needle, the application site was slightly massaged. In the retractable needle technique, the same technique was performed but, at the end of the application and full compression of the vial, the retractable device introduced the needle inside the body of the syringe before it was removed from the dorsal-gluteal region.

At the medical-surgical hospitalization Unit, patients who received subcutaneous insulin were assessed. Control group patients received insulin through the conventional technique. The insulin application site was defined according to each patient's application turnover and was outlined with a specific pen for skin marking after the application. Patients were assessed 24 hours later to detect the presence of bruising at the application site.

At the Emergency Care Unit, patients who received intramuscular drugs were assessed. All drugs were applied in the patients' dorsal-gluteal region at a private room. The dorsal-gluteal region used for applying the intramuscular injections, as that was the body area standardized for this type of procedure at the institution's Emergency Care Unit.

The collected data were processed and launched in an electronic Excel® worksheet. Student's t-test was used to analyze the variables, with significance set at 5%. Thus, it was considered that differences existed between groups if p <0.05.



Table 1 shows the active ingredients and the volume of drugs used in intramuscular injections, applied with the conventional technique and retractable fixed needles.

The administered drugs were prescribed for patient treatment at the Emergency Care Unit. Drug volume ranged between 1 and 4 ml, according to the drug or diluent used.

The comparison of volume distribution per technique, separately for each pain degree, showed that, for the total group of patients, no difference occurred in the mean pain score according to the different volumes used (p=0.364), according to Table 2. For this comparison, the Chi-Square test was used, with significance set at 5%. The results show no difference in volume distribution between the technique for any pain level.

Table 3 shows that no statistical difference was found for the analyzed variables with regard to the compared techniques.



Table 4 shows difference between the groups regarding the pain scale, evidencing that, on average, the pain score is higher in the group in which the conventional technique was used (p<0.001). Test power when comparing both groups regarding the pain scale corresponded to 0.98 when comparing the entire sample and 0.97 when comparing the intramuscular injection group, with significance set at 5%.



On the average, the bruising score is higher in the patient group in which the conventional technique was used (p<0.029), according to Table 5.




Usually, the drug aspiration needle is exchanged for another with a view to intramuscular, subcutaneous or intradermal administration. The justifications given for this practice include: muscle tissue irritation, alteration in the sharpness of the needle bevel with a consequent increase in the patient's painful sensation. Also, the risk of health professionals contaminating the aspiration needle while handling it is mentioned. These justifications are based on practices that are considered correct, without confirmatory scientific evidence. Factors like technological advances are not taken into account, which permit manufacturing material and equipment that facilitate care practices, offering safety and reducing occupational risks for health professionals.

One important reflection that is due is that aseptic handling of materials impedes drug contamination, independently of what technique is used. Professionals and institutions should join efforts for work practices to reflect this concern.

In clinical practice, the belief exists that drawing back retractable needles before removing them from the skin in case of subcutaneous injections could provoke traumas and bruising. This study, on the other hand, evidenced no major bruising when using retractable fixed needles to apply subcutaneous injections. This finding confirms that using the safety device to apply subcutaneous injections is safe to use with patients.

Initially, the researchers had planned to assess the intramuscular injection application using one single drug and volume but, after a pilot study at the Emergency Care Unit, it was observed that the time needed for data collection could turn the study unfeasible. Therefore, the decision was made to administer volumes between 1 and 4 ml for application in the dorsal-gluteal region. When comparing pain levels according to the administered volume, no changes in pain perceptions were found, neither with the conventional nor with the retractable fixed needle technique.

Training health professionals for injection application with retractable fixed needles is necessary with a view to the clarification of doubts, adequate use of available resources and protection offered by the safety device.

Other studies should be conducted on injections with retractable needles to assess their introduction in clinical practice, their impact on the reduction of accidents with piercing-cutting material, costs associated with new technologies and the production of solid health residues.



Technological innovations are meant to improve care quality and facilitate the execution of procedures, guaranteeing and preserving patients and health professionals' safety. The use of safety devices like syringes with retractable fixed needles is a prevention practice that guarantees compliance with NR-32, benefitting workers and health institutions.

Based on the obtained results, it can be affirmed that using syringes with retractable fixed needle safety devices neither compromise painful feelings when applying intramuscular and subcutaneous injections nor enhance the risk of bruising in case of subcutaneous applications. Thus, the use of these safety devices can be recommended in clinical practice.



We acknowledge the financial support of the company Biodina SP Representações S/C Ltda, Ana Cristina Rossetti and care nursing staff of the Hospital Municipal Dr. Moysés Deutsch – M'Boi Mirim, for their support in this project.



1. Hutin Y, Hauri A, Chiarello L, Catlin M, Stilwell B, Ghebrehiwet T, et al. Injection Safety Best Practices Development Group. Best infection control practices for intradermal, subcutaneous, and intramuscular needle injections. Bull World Health Organ. 2003;81(7):491-500.         [ Links ]

2. Wilburn SQ, Eijkemans G. Preventing needlestick injuries among healthcare workers: a WHO-ICN collaboration. Int J Occup Envir Health. 2004;10:451-6.         [ Links ]

3. Prüss-Üstün A, Rapiti E, Hutin Y. Sharps injuries: global burden of disease from sharps injuries to health-care workers [Internet] 2003 [acesso 3 mai 2010]. Geneva: World Health Organization; 2003. Quantifying environmental health impacts. (WHO Environmental Burden of Disease, n. 3). Disponível em::         [ Links ]

4. Chance S. Syringe safety controls. J Clin Eng. 2006;31(3):152-5.         [ Links ]

5. O'Malley EM, Scott RD 2nd, Gayle J, Dekutoski J, Foltzer M, Lundstrom TS, et al. Costs of management of occupational exposures to blood and body fluids. Infect Control Hosp Epidemiol. 2007;28(7):774-82.         [ Links ]

6. Centers for Disease Control and Prevention. Workbook for designing, implementing, and evaluating a sharps injury prevention program [Internet] 2008 [acesso 10 mai 2010]. Disponível em:         [ Links ]

7. Rapparini C. Occupational HIV infection among health care workers exposed to blood and body fluids in Brazil. Am J Infect Control. 2006;34(4):237-40.         [ Links ]

8. Marziale MH, Rodrigues CM. A produção científica sobre os acidentes de trabalho com material perfurocortante entre trabalhadores de enfermagem. Rev. Latino-Am. Enfermagem. 2002;10(4):571-7.         [ Links ]

9. Canini SRMS, Moraes AS, Gir E, Freitas ICM. Fatores associados a acidentes percutâneos na equipe de enfermagem de um hospital universitário de nível terciário. Rev. Latino-Am. Enfermagem. 2008;16(5):818-23.         [ Links ]

10. Vigilância epidemiológica dos acidentes ocupacionais com exposição a materiais biológicos no estado de São Paulo. P.64-71. Boletim epidemiológico [Internet] 2008 [acesso 20 abr 2010]; 15(1):64-71. Disponível em:        [ Links ]

11. Ministério do Trabalho e Emprego (BR). Portaria n. 485, de 11 de novembro de 2005. Aprova a Norma Regulamentadora n. 32 (Segurança e Saúde no Trabalho em Estabelecimentos de Saúde) [Internet]. Diário Oficial da República Federativa do Brasil, Brasília (DF); Nov 2005. [acesso 10 abr 2010]. Disponível em:        [ Links ]

12. Ministério do Trabalho e Emprego (BR). Portaria n. 939, de 18 de novembro de 2008. Publica o cronograma para promover a substituição dos materiais perfurocortantes por outros com dispositivo de segurança, previsto na Norma Regulamentadora n.32 [Internet]. Diário Oficial da República Federativa do Brasil, Brasília (DF); 2005 Nov 11 [acesso 10 abr 2010]. Disponível em:        [ Links ]

13. Cabral IE, revisora. Administração de medicamentos. Rio de Janeiro: Reichmann; 2002. p. 274-306.         [ Links ]

14. Oliveira MA, Takahashi RF. Questões práticas relacionadas à aplicação de vacinas. In: Farhat CK, Weckx LY, Carvalho LH, Menezes RC. Imunizações: fundamentos e prática. 5.ed. São Paulo: Atheneu; 2000. p. 137-48.         [ Links ]

15. Wynaden D, Landsborough I, Chapman R, McGowan S, Lapsley J, Finn M. Establishing best practice guidelines for administration of intra muscular injections in the adult: a systematic review of the literature. Contemp Nurse. 2005;20(2):267-77.         [ Links ]

16. Soares NR. Administração de medicamentos na enfermagem. Rio de Janeiro: EPUB; 2001. 376 p.         [ Links ]

17. Gilsenan I. Injections: a practical guide to giving. Nurs Times. 2000;96(33):43-4.         [ Links ]

18. Workman B. Safe injection techniques. Nurs Stand. 1999;13(39):47-53.         [ Links ]

19. Beyea SC, Nicoll LH. Administration of medications via the intramuscular route: an integrative review of the literature and research-based protocol for the procedure. Appl Nurs Res. 1995;8(1):23-33.         [ Links ]

20. Rodger MA; King L. Drawing up and administering intramuscular injections: a review of the literature. J Adv Nurs. 2000;1(3):574-82.         [ Links ]

21. Sociedade Brasileira de Diabetes. Aplicação de insulina. In: Sociedade Brasileira de Diabetes. Diretrizes da Sociedade Brasileira de Diabetes 2009. São Paulo: SBD; 2009. p. 171-6.         [ Links ]

22. Atkinson WL, Pickering LK, Schwartz B, Weniger BG, Iskander JK, Watson JC. General recommendations on immunization. Recommendations of the Advisory Committee on Immunization Practices (ACIP) and the American Academy of Family Physicians (AAFP). MMWR [Internet] 2002 [acesso 10 abr 2010]; 51 (RR02):1-36. Available from:        [ Links ]

23. Klingman L. Effects of changing needles prior to administering heparin subcutaneously. Heart Lung. 2000;29(1):70-5.         [ Links ]

24. Rock D. Does drawing up technique influence patients' perception of pain at the injection site? Aust N Z J Ment Health Nurs. 2000;9(3):147-51.         [ Links ]

25. Salomon ME, Halperin R, Yee J. Evaluation of the two-needle strategy for reducing reactions to DPT vaccination. Am J Dis Child. 1987;141(7):796-8.         [ Links ]

26. Teixeira MJ, Figueiró JAB. Avaliação do doente com dor. In: Dor: Epidemiologia, fisiopatologia, avaliação, síndromes dolorosas e tratamento. São Paulo: Grupo Editorial Moreira Jr, 2001. p. 58-68.         [ Links ]



Corresponding Author:
Luiz Carlos Ribeiro Lamblet
Praça General Craveiro Lopes, 19, Apto 2110
Bela Vista
CEP: 01319-070, São Paulo, SP, Brasil



Received: Ago. 19th 2010
Accepted: Ago. 15th 2011

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