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The incidence of coring with blunt versus sharp needles
Journal of Clinical Anesthesia (2014) 26, 152–154
Special Article
The incidence of coring with blunt versus sharp needles Tariq Wani MD (Assistant Professor)a , Anupama Wadhwa MD (Associate Professor) b , Joseph D. Tobias MD (Professor) a,c,⁎ a
Department of Anesthesiology & Pain Medicine, Nationwide Children’s Hospital, Columbus, OH 43205, USA Department of Anesthesiology, University of Louisville, Louisville, KY 40202, USA c Department of Anesthesiology, The Ohio State University, Columbus, OH 43210, USA b
Received 5 February 2013; revised 1 October 2013; accepted 2 October 2013
Keywords: Coring; Medication vials; Patient safety; Rubber vials
Abstract With the advent of safety needles to prevent inadvertent needle sticks in the operating room (OR), a potentially new issue has arisen. These needles may result in coring, or the shaving off of fragments of the rubber stopper, when the needle is pierced through the rubber stopper of the medication vial. These fragments may be left in the vial and then drawn up with the medication and possibly injected into patients. The current study prospectively evaluated the incidence of coring when blunt and sharp needles were used to pierce rubber topped vials. We also evaluated the incidence of coring in empty medication vials with rubber tops. The rubber caps were then pierced with either an18-gauge sharp hypodermic needle or a blunt plastic (safety) needle. Coring occurred in 102 of 250 (40.8%) vials when a blunt needle was used versus 9 of 215 (4.2%) vials with a sharp needle (P b 0.0001). A significant incidence of coring was demonstrated when a blunt plastic safety needle was used. This situation is potentially a patient safety hazard and methods to eliminate this problem are needed. © 2014 Elsevier Inc. All rights reserved.
1. Introduction Safety concerns focus not only on patients, but also healthcare providers. One such concern includes means to limit the exposure of healthcare providers to inadvertent needle sticks. The issue of needle stick injuries remains a major concern for anesthesia care providers. To some extent, the potential for such problems has been addressed by introducing ⁎ Correspondence: Joseph D. Tobias, MD, Chairman, Department of Anesthesiology & Pain Medicine, Nationwide Children's Hospital, 700 Children's Drive, Columbus, OH 43205, USA. Tel.: (614) 722–4203; fax: (614) 722–4203. E-mail address: [email protected] (J.D. Tobias). 0952-8180/$ – see front matter © 2014 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.jclinane.2013.10.007
and increasing the use of blunt tip needles [1–3]. The blunt needle has virtually replaced sharp needles in many operating rooms (ORs) and anesthesia areas for accessing vials and preparing perioperative medications. However, the use of these needles may increase the potential for “coring”, or a phenomenon in which fragments of the rubber stopper are shaved off when a needle is stuck into the rubber stopper of the medication vial. These fragments may be left in the vial and then drawn up with the medication and potentially injected into patients. The implications of this small particle of rubber are unknown [4–6]. We hypothesized that in the OR coring happens on a regular basis. The current study prospectively evaluated the incidence of coring when blunt and sharp needles are used to enter rubber topped vials.
The incidence of coring with blunt versus sharp needles Table 1
Incidence of coring using blunt needles
Medication vial
No. of vials
No. of cores
Vials with cores (%)
Succinylcholine Propofol Etomidate Rocuronium Cefazolin Dexamethasone Vecuronium Neostigmine Metoprolol Esmolol Total
35 80 12 56 36 6 1 11 6 7 250
4 46 1 10 31 1 1 7 0 1 102
11 58 8.3 17.8 86.1 16.7 100 63.6 0 14 40.8
2. Materials and methods A total of 465 empty medication vials with rubber tops were collected from the ORs of the University of Louisville Hospital. The vials were rinsed with saline and the rubber caps were replaced. Anesthesia providers (ie, certified registered nurse anesthetists or anesthesiology residents) were randomized via sealed envelope assignment to use an 18-gauge sharp hypodermic needle or a blunt plastic (safety) needle to pierce the rubber caps from 10 vials. A blinded investigator collected these vials, removed the rubber caps, and filled each vial with 5 mL of normal saline. This solution was then filtered through a 0.45 μm filter. The filtrate was examined with the naked eye for any particulate matter. A Fisher’s Exact test was used to compare the incidence of coring when a blunt needle was used as compared with a sharp needle.
153 215 (4.2%) vials with a sharp needle (P b 0.0001). The incidence of coring with blunt and sharp needles in various medication vials is listed in Tables 1 and 2. Among the various medication vials, the highest incidence of coring was noted in propofol, cefazolin, and neostigmine vials with an incidence of 58%, 86%, and 63.6% respectively.
4. Discussion The current study confirms the hypothesis that coring occurs in a significant percentage of cases when a blunt needle is used. The clinical implication is the possibility of the core being loaded into the syringe and injected into the patient with its potential for deleterious physiological effects. Coring has been previously evaluated when using vials of prednisolone acetate [7]. The medication was drawn from the vial using an 18-gauge cutting beveled needle. The investigators noted an incidence of coring of 21%; however, only 11 of the 21 cases were visible to the naked eye. Core size ranged from 0.6 to 1.1 mm and in one of the 21 cases, the core was ejected through a 20-gauge needle, which was subsequently used to draw up the medication, suggesting that these cores can be aspirated into a syringe and potentially injected into a patient. Other reports have documented coring when using insulin syringes and vials of contrast solution [8,9]. Although the clinical consequences of this problem aside from latex sensitization and clinically occult pulmonary granulomas remain unknown, it has been suggested that embolization of this particulate matter can compromise tissue perfusion [4,10,11]. The consequences would range from no clinically overt effect to significant morbidity and be dependent on the vascular bed affected.
3. Results We found that coring occurred in 102 of 250 (40.8%) vials when a blunt needle was used as compared with 9 of Table 2
Incidence of coring using sharp needles
Medication vial
No. of vials
No. of cores
Vials with cores (%)
Succinylcholine Propofol Etomidate Rocuronium Cefazolin Dexamethasone Vecuronium Neostigmine Metoprolol Esmolol Total
34 74 3 42 39 6 1 8 3 5 215
0 8 0 1 0 0 0 0 0 0 9
0 10.8 0 2.3 0 0 0 0 0 0 4.2
Fig. 1 Photograph of hole in a cap and the cored piece that may be produced when a blunt needle is used.
154
T. Wani et al. developed to eliminate this problem regardless of the type of needle used. Until then, we need to consider that coring may occur and develop practical ways to limit its impact on our patients.
References
Fig. 2 View of a core fragment (circled) noted on the inside of a propofol vial.
Coring occurs more regularly than may be visible to the naked eye [Figs. 1, 2]. The problem appears to be particularly relevant when considering the use of propofol and with the use of blunt needles [12,13]. The use of blunt needles has become widespread throughout most ORs, to decrease the risk of inadvertent needle sticks. When loading medications for spinal anesthesia, needles with filters are routinely used. This filtering ensures that glass fragments do not enter the medication and hence the patient. Another technique to limit coring has recently been reviewed [14]. As those authors report, the needle should be inserted at a 45° to 60° angle to the top of the vial with the needle bevel or opening facing up. As the needle is advanced, a small amount of pressure is applied and the angle is gradually increased as the needle enters the vial. The angle of entry of the needle should be 90° as the needle bevel pierces the stopper. Although the incidence of coring is decreased with smaller-gauge needles, the cored piece is more difficult to see and thus more likely to be drawn up and injected. The mandatory use of filter needles for loading any medication into syringes may eliminate this problem. The other issue that needs to be taken into consideration is the type of rubber that is used for the top of medication vials. It may be that new manufacturing techniques may be
[1] Elder A, Paterson C. Sharps injuries in UK health care: a review of injury rates, viral transmission and potential efficacy of safety devices. Occup Med 2006;56:566-74. [2] Berguer R, Heller PJ. Strategies for preventing sharps injuries in the oprating room. Surg Clin North Am 2005;85:1299-305. [3] Kempen PM. Assessing blunt cannulae as replacements for hypodermic needles during intravenous therapy: safety and utility. Infect Control Hosp Epidemiol 1997;18:169-74. [4] Kirkpatrick CJ, Lehr HA, Otto M, Bittinger F, Rangoonwala R. Clinical implications of circulating particulate contamination of parenteral injections: a review. Critical Care and Shock 1999;4: 166-73. [5] Chikungwa MT. Are we causing latex sensitisation unknowingly? Anaesthesia 2000;55:828. [6] Nyabadza M. Preventing latex sensitisation and foreign body microemboli. Anaesthesia 2001;56:705. [7] Campagna R, Pessis E, Guerini H, Feydy A, Drapé JL. Occurrence of coring after needle insertion through a rubber stopper: study with prednisolone acetate. Eur Radiol 2013;23:424-7. [8] Asakura T, Seino H, Nozaki S, Abe R. Occurrence of coring in insulin vials and possibility of rubber piece contamination by self-injection. Yakugaku Zasshi 2001;121:459-63. [9] Sakai O, Furuse M, Nakashima N. Cut-off fragments of rubber caps of bottles of contrast material: foreign bodies in the drip infusion system. AJNR Am J Neuroradiol 1996;17:1194-5. [10] Lehr HA, Brunner J, Rangoonwala R, Kirkpatrick CJ. Particulate matter contamination of intravenous antibiotics aggravates loss of functional capillary density in postischemic striated muscle. Am J Respir Crit Care Med 2002;165:514-20. [11] Thomsen DJ, Burke TG. Lack of latex allergen contamination of solutions withdrawn from vials with natural rubber stoppers. Am J Health Sys Pharm 2000;57:44-7. [12] Adachi Y, Takigami J, Watanabe K, Satoh T. A case of coring using a 1% Diprivan vial. Masui 2001;50:635-6. [13] Shiroyama K. The incidence of “coring” during aspiration of propofol from a 50-mL vial. J Anesth 2001;15:120. [14] Roth JV. How to enter a medication vial without coring. Anesth Analg 2007;104:1615.
Special Article
The incidence of coring with blunt versus sharp needles Tariq Wani MD (Assistant Professor)a , Anupama Wadhwa MD (Associate Professor) b , Joseph D. Tobias MD (Professor) a,c,⁎ a
Department of Anesthesiology & Pain Medicine, Nationwide Children’s Hospital, Columbus, OH 43205, USA Department of Anesthesiology, University of Louisville, Louisville, KY 40202, USA c Department of Anesthesiology, The Ohio State University, Columbus, OH 43210, USA b
Received 5 February 2013; revised 1 October 2013; accepted 2 October 2013
Keywords: Coring; Medication vials; Patient safety; Rubber vials
Abstract With the advent of safety needles to prevent inadvertent needle sticks in the operating room (OR), a potentially new issue has arisen. These needles may result in coring, or the shaving off of fragments of the rubber stopper, when the needle is pierced through the rubber stopper of the medication vial. These fragments may be left in the vial and then drawn up with the medication and possibly injected into patients. The current study prospectively evaluated the incidence of coring when blunt and sharp needles were used to pierce rubber topped vials. We also evaluated the incidence of coring in empty medication vials with rubber tops. The rubber caps were then pierced with either an18-gauge sharp hypodermic needle or a blunt plastic (safety) needle. Coring occurred in 102 of 250 (40.8%) vials when a blunt needle was used versus 9 of 215 (4.2%) vials with a sharp needle (P b 0.0001). A significant incidence of coring was demonstrated when a blunt plastic safety needle was used. This situation is potentially a patient safety hazard and methods to eliminate this problem are needed. © 2014 Elsevier Inc. All rights reserved.
1. Introduction Safety concerns focus not only on patients, but also healthcare providers. One such concern includes means to limit the exposure of healthcare providers to inadvertent needle sticks. The issue of needle stick injuries remains a major concern for anesthesia care providers. To some extent, the potential for such problems has been addressed by introducing ⁎ Correspondence: Joseph D. Tobias, MD, Chairman, Department of Anesthesiology & Pain Medicine, Nationwide Children's Hospital, 700 Children's Drive, Columbus, OH 43205, USA. Tel.: (614) 722–4203; fax: (614) 722–4203. E-mail address: [email protected] (J.D. Tobias). 0952-8180/$ – see front matter © 2014 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.jclinane.2013.10.007
and increasing the use of blunt tip needles [1–3]. The blunt needle has virtually replaced sharp needles in many operating rooms (ORs) and anesthesia areas for accessing vials and preparing perioperative medications. However, the use of these needles may increase the potential for “coring”, or a phenomenon in which fragments of the rubber stopper are shaved off when a needle is stuck into the rubber stopper of the medication vial. These fragments may be left in the vial and then drawn up with the medication and potentially injected into patients. The implications of this small particle of rubber are unknown [4–6]. We hypothesized that in the OR coring happens on a regular basis. The current study prospectively evaluated the incidence of coring when blunt and sharp needles are used to enter rubber topped vials.
The incidence of coring with blunt versus sharp needles Table 1
Incidence of coring using blunt needles
Medication vial
No. of vials
No. of cores
Vials with cores (%)
Succinylcholine Propofol Etomidate Rocuronium Cefazolin Dexamethasone Vecuronium Neostigmine Metoprolol Esmolol Total
35 80 12 56 36 6 1 11 6 7 250
4 46 1 10 31 1 1 7 0 1 102
11 58 8.3 17.8 86.1 16.7 100 63.6 0 14 40.8
2. Materials and methods A total of 465 empty medication vials with rubber tops were collected from the ORs of the University of Louisville Hospital. The vials were rinsed with saline and the rubber caps were replaced. Anesthesia providers (ie, certified registered nurse anesthetists or anesthesiology residents) were randomized via sealed envelope assignment to use an 18-gauge sharp hypodermic needle or a blunt plastic (safety) needle to pierce the rubber caps from 10 vials. A blinded investigator collected these vials, removed the rubber caps, and filled each vial with 5 mL of normal saline. This solution was then filtered through a 0.45 μm filter. The filtrate was examined with the naked eye for any particulate matter. A Fisher’s Exact test was used to compare the incidence of coring when a blunt needle was used as compared with a sharp needle.
153 215 (4.2%) vials with a sharp needle (P b 0.0001). The incidence of coring with blunt and sharp needles in various medication vials is listed in Tables 1 and 2. Among the various medication vials, the highest incidence of coring was noted in propofol, cefazolin, and neostigmine vials with an incidence of 58%, 86%, and 63.6% respectively.
4. Discussion The current study confirms the hypothesis that coring occurs in a significant percentage of cases when a blunt needle is used. The clinical implication is the possibility of the core being loaded into the syringe and injected into the patient with its potential for deleterious physiological effects. Coring has been previously evaluated when using vials of prednisolone acetate [7]. The medication was drawn from the vial using an 18-gauge cutting beveled needle. The investigators noted an incidence of coring of 21%; however, only 11 of the 21 cases were visible to the naked eye. Core size ranged from 0.6 to 1.1 mm and in one of the 21 cases, the core was ejected through a 20-gauge needle, which was subsequently used to draw up the medication, suggesting that these cores can be aspirated into a syringe and potentially injected into a patient. Other reports have documented coring when using insulin syringes and vials of contrast solution [8,9]. Although the clinical consequences of this problem aside from latex sensitization and clinically occult pulmonary granulomas remain unknown, it has been suggested that embolization of this particulate matter can compromise tissue perfusion [4,10,11]. The consequences would range from no clinically overt effect to significant morbidity and be dependent on the vascular bed affected.
3. Results We found that coring occurred in 102 of 250 (40.8%) vials when a blunt needle was used as compared with 9 of Table 2
Incidence of coring using sharp needles
Medication vial
No. of vials
No. of cores
Vials with cores (%)
Succinylcholine Propofol Etomidate Rocuronium Cefazolin Dexamethasone Vecuronium Neostigmine Metoprolol Esmolol Total
34 74 3 42 39 6 1 8 3 5 215
0 8 0 1 0 0 0 0 0 0 9
0 10.8 0 2.3 0 0 0 0 0 0 4.2
Fig. 1 Photograph of hole in a cap and the cored piece that may be produced when a blunt needle is used.
154
T. Wani et al. developed to eliminate this problem regardless of the type of needle used. Until then, we need to consider that coring may occur and develop practical ways to limit its impact on our patients.
References
Fig. 2 View of a core fragment (circled) noted on the inside of a propofol vial.
Coring occurs more regularly than may be visible to the naked eye [Figs. 1, 2]. The problem appears to be particularly relevant when considering the use of propofol and with the use of blunt needles [12,13]. The use of blunt needles has become widespread throughout most ORs, to decrease the risk of inadvertent needle sticks. When loading medications for spinal anesthesia, needles with filters are routinely used. This filtering ensures that glass fragments do not enter the medication and hence the patient. Another technique to limit coring has recently been reviewed [14]. As those authors report, the needle should be inserted at a 45° to 60° angle to the top of the vial with the needle bevel or opening facing up. As the needle is advanced, a small amount of pressure is applied and the angle is gradually increased as the needle enters the vial. The angle of entry of the needle should be 90° as the needle bevel pierces the stopper. Although the incidence of coring is decreased with smaller-gauge needles, the cored piece is more difficult to see and thus more likely to be drawn up and injected. The mandatory use of filter needles for loading any medication into syringes may eliminate this problem. The other issue that needs to be taken into consideration is the type of rubber that is used for the top of medication vials. It may be that new manufacturing techniques may be
[1] Elder A, Paterson C. Sharps injuries in UK health care: a review of injury rates, viral transmission and potential efficacy of safety devices. Occup Med 2006;56:566-74. [2] Berguer R, Heller PJ. Strategies for preventing sharps injuries in the oprating room. Surg Clin North Am 2005;85:1299-305. [3] Kempen PM. Assessing blunt cannulae as replacements for hypodermic needles during intravenous therapy: safety and utility. Infect Control Hosp Epidemiol 1997;18:169-74. [4] Kirkpatrick CJ, Lehr HA, Otto M, Bittinger F, Rangoonwala R. Clinical implications of circulating particulate contamination of parenteral injections: a review. Critical Care and Shock 1999;4: 166-73. [5] Chikungwa MT. Are we causing latex sensitisation unknowingly? Anaesthesia 2000;55:828. [6] Nyabadza M. Preventing latex sensitisation and foreign body microemboli. Anaesthesia 2001;56:705. [7] Campagna R, Pessis E, Guerini H, Feydy A, Drapé JL. Occurrence of coring after needle insertion through a rubber stopper: study with prednisolone acetate. Eur Radiol 2013;23:424-7. [8] Asakura T, Seino H, Nozaki S, Abe R. Occurrence of coring in insulin vials and possibility of rubber piece contamination by self-injection. Yakugaku Zasshi 2001;121:459-63. [9] Sakai O, Furuse M, Nakashima N. Cut-off fragments of rubber caps of bottles of contrast material: foreign bodies in the drip infusion system. AJNR Am J Neuroradiol 1996;17:1194-5. [10] Lehr HA, Brunner J, Rangoonwala R, Kirkpatrick CJ. Particulate matter contamination of intravenous antibiotics aggravates loss of functional capillary density in postischemic striated muscle. Am J Respir Crit Care Med 2002;165:514-20. [11] Thomsen DJ, Burke TG. Lack of latex allergen contamination of solutions withdrawn from vials with natural rubber stoppers. Am J Health Sys Pharm 2000;57:44-7. [12] Adachi Y, Takigami J, Watanabe K, Satoh T. A case of coring using a 1% Diprivan vial. Masui 2001;50:635-6. [13] Shiroyama K. The incidence of “coring” during aspiration of propofol from a 50-mL vial. J Anesth 2001;15:120. [14] Roth JV. How to enter a medication vial without coring. Anesth Analg 2007;104:1615.