Abstract
Abstract
Background and Objectives:
A comparison of metal needles and plastic cannulae (winged and nonwinged) for continuous subcutaneous infusion was done during a quality improvement project to reduce device-induced complications at our hospital.
Design, Setting, and Measurements:
Data were collected on incidence of site reactions (bruising, swelling, erythema, and blisters); mechanical complications (kinking and dislodgement); device durability; type, and volume of medications; and incidence of needle-stick injuries. All infusion devices used for patients in the Palliative Care Service from February 3 to March 26, 2014 were studied. Devices examined were: winged metal needle (Venofix®, 23G, B. Braun Melsungen AG, Melsungen, Germany), winged vialon cannula (BD Nexiva™, 24G, Becton Dickinson Infusion Therapy Systems Inc., Sandy, UT), and nonwinged polyurethane cannula (Introcan Safety®, 24G, B. Braun Medical, Mundelein, IL).
Results:
Thirty devices (10 per type) were used. Incidence of site reactions was 50.0%, 10.0%, and 0.0% for the metal needles, polyurethane cannulae, and vialon cannulae, respectively. Incidence of mechanical complications was 20.0% for the polyurethane cannulae and 0.0% for the metal needles and vialon cannulae. Duration of use was up to 60 hours, 83 hours, and 113 hours for the metal needles, polyurethane cannulae, and vialon cannulae, respectively. Daily volumes infused were up to 28.9 mL, 60.0 mL, and 29.4 mL for the metal needles, polyurethane cannulae, and vialon cannulae, respectively. No needle-stick injuries occurred.
Conclusions:
The winged vialon cannula was the most durable, with no site reactions or mechanical complications, tolerating a volume comparable to that of the metal needle. We suggest its utilization for continuous subcutaneous infusions and consideration of future randomized controlled trials with an integrated economic evaluation for further in-depth comparisons of subcutaneous indwelling devices.
Introduction
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However, the subcutaneous route is associated with local site reactions such as erythema and swelling, incidences of which range from 4%–24%.7,8 Site reactions are associated with the use of irritant drugs, hypertonicity or hypotonicity of constituents and nickel allergy.7–11 Nickel is present in indwelling metal winged needles and is the most common allergen noted in patch tests performed locally. 12 There have been recent technological advances in subcutaneous devices, such as using plastic as a material to reduce allergenic site reactions, a winged stabilization platform to reduce mechanical complications, and automatically deployed needle tip sheaths to minimize needle-stick injuries.8,9,13–22 Reduction of complications is associated with increased device durability, overall cost effectiveness, and has an impact on resource planning.20–22 We undertook a quality improvement project to change from metal needles to nonmetal cannulae and examined the durability, mechanical stability, and site reactions of different devices.
Methods
Design and setting
This observational quality improvement project was carried out in the inpatient setting of a 400-bed acute hospital in Singapore for patients under the care of the palliative care service. The palliative care service is a consultative service composed of four nurses, two consultants, one registrar, and one social worker.
Project implementation
The devices examined were: winged metal (chrome-nickel steel) needle (Venofix®, 23G, B. Braun Melsungen AG, Melsungen, Germany), which was the original device we were using, winged vialon cannula (BD Nexiva ™, 24G, Becton Dickinson Infusion Therapy Systems Inc., Sandy, UT) and nonwinged polyurethane cannula (Introcan Safety ®, 24G, B. Braun Medical, Mundelein, IL), which were the two devices under consideration.23–25
Patients were assigned consecutively to each of the three devices. If the patient required two concurrent infusions, a winged metal needle and a plastic cannula were inserted. If site reactions or mechanical complications occurred, the device would be changed from a metal to a plastic cannula and vice versa.
There were multiple strategies to reduce confounding. First, all four palliative care nurses were trained in the use of a standardized procedure for subcutaneous infusion device insertion and insertion was performed by consecutively assigned palliative care nurses during this project. Each device was inserted in a standardized manner aseptically at a 45-degree angle to the skin, secured in place with a Tegaderm® dressing (3M, St. Paul, MN) and subsequently connected to a standard infusion tubing. The polyurethane cannula also required an additional Y connector (MicroClave®, Icu Medical Inc., San Clemente, CA) that was attached aseptically. 26 Second, the site of infusion was determined by the palliative care nurse in a standardized manner before the type of device to be chosen was known. Sites were excluded if the skin was edematous, painful, or if it was over a skin fold. 27 Third, medications were delivered solely via the Braun Perfusor® Space pump (B. Braun Medical). Fourth, medications used were common to palliative care with a low propensity for causing site reactions and were diluted with normal saline as per the Palliative Care Formulary. 28 Fifth, the maximum daily infusion volume allowed through the device was also fixed as per guidelines. 29 Finally, monitoring was done by ward staff nurses not involved in the project.
Patients were monitored for site reactions (such as bruising, swelling, blisters, and erythema) and mechanical complications (such as kinking and dislodgement). Lucid and communicative patients were asked their pain scores during insertion and during the presence of the indwelling device at the insertion site according to the Numeric Pain Rating Scale. 30 Uncommunicative patients were observed for behavioral manifestations of pain at the insertion site. The subcutaneous site and pain assessments were reviewed every 4 hours using a departmental audit tool and complications were recorded as either present or absent. The type and volume of medication infused, duration of device use, incidence of needle-stick injuries, patient's demographic data. and medical diagnosis were also collected.
Data collection and analysis
All devices used for patients who required subcutaneous infusions from February 3 to March 26, 2014 were studied. Simple descriptive analyses were performed for data that were then presented using measures of central tendency or percentages.
Ethical considerations
Because this was a quality improvement project, our institutional policy did not require us to seek Institutional Review Board approval. As per standard clinical practice, all lucid and communicative patients were informed regarding the palliative consult (with inherent patient demographic and medical diagnosis data collection) and the need for subcutaneous infusion via a device (with inherent data collection on device usage and performance). If the patient was not lucid or communicative, the primary caregiver would be informed. Devices were inserted if patients and/or caregivers were agreeable and were stopped upon request. Patient identifiers were removed and hard copy documents were stored in a locked cabinet within the department. Computer-based data were stored in a password-protected device with access limited to the first author.
Results
The mean age of the patients was 67.7 ± 9.5 years, 59.3% were male, 66.7% were Chinese, and 44.4% had cancer. Fourteen patients were communicative and lucid at the start of their infusion. The most common symptom treated was dyspnea (n = 16) and the most common medication used was fentanyl (n = 23; Table 1).
All data are numbers (%) unless stated otherwise.
Device performance and usage is described in Table 2. Thirty devices were used (10 metal, 10 vialon, and 10 polyurethane) on 27 patients, of whom 3 patients had exposure to 2 devices (metal and vialon or metal and polyurethane). The most common insertion site was over the patient's deltoid.
Daily volumes of medications infused were up to 28.9 mL, 29.4 mL, and 60.0 mL via the metal needles, vialon, and polyurethane cannulae, respectively. Despite tolerating the smallest volumes of infusion, the metal needles had the highest frequency of site reactions (50%). The polyurethane cannulae had a 10% incidence of site reactions while the vialon cannulae had none. Incidence of mechanical complications was highest for the polyurethane cannulae (20%) and none for the metal needles and vialon cannulae.
The duration for which the devices remained in place before removal due to complications was up to 60 hours and 83 hours for the metal needles and polyurethane cannulae, respectively. The vialon cannulae remained in place until patient demise or infusion discontinuation and this duration was up to 113 hours. No needle-stick injury to medical staff occurred during the project.
Discussion
As described in literature, the winged vialon cannula is most durable because it has the fewest complications.8,9,13–18,20–22 Considerations influencing device choice would include device site reaction and mechanical complications risk (such as device material and stabilization mechanism) and safety considerations (Table 3).
The cons of the different devices are underlined.
The presence of a winged design for the metal needle improved the ergonomics of device insertion and subsequent stabilization. However, it had the highest incidence of site reactions despite having the lowest daily infused volume, possibly because of the presence of nickel. Although no needle-stick injury occurred, it is known that metal needles pose safety hazards. A needle-stick injury commonly induces much staff anxiety given the transmissibility of blood-borne infections. Treatment of site reactions and needle-stick injuries also increases health care costs.19–22,31–33
The nonwinged polyurethane cannula with lesser known propensity for allergy also had fewer site reactions. It was designed to reduce needle-stick injury, however, it suffered from mechanical complications due to a lack of a stabilization mechanism.
The winged vialon cannula with inherent needle safety, a stabilization mechanism and a lesser known propensity for allergy, performed the best with no site or mechanical complications. Vialon, in comparison to other plastics, also has a lower risk of bacterial adherence, theoretically reducing the risk of infection and increasing its durability. 34
Limitations of this project include the small number of devices surveyed and a lack of blinding. The project was also not designed for evaluation of cost effectiveness. Although there was nonstandardization of infusion fluids between patients, this was done to reflect usual clinical practice. The strategies to reduce confounding factors were described earlier, and our findings are corroborated in the current literature, which had studies with similarly small numbers.14,18
In conclusion, the winged vialon cannula is most durable with fewest site reactions and mechanical complications, suggesting its benefit for use in subcutaneous infusions. The authors suggest future randomized controlled trials with an integrated economic evaluation for further in-depth comparisons of subcutaneous indwelling devices.
Footnotes
Author Disclosure Statement
The authors declare that no competing financial interests exist.