An angled insertion technique using 6-mm needles markedly reduces the risk of intramuscular injections in children and adolescents

Ultrasound Detected Subcutaneous Changes in a Pediatric Cohort After Initiation of a New Insulin Pump or Glucose Sensor

Objective: This study examined subcutaneous tissue changes at sites used by continuous subcutaneous insulin infusion (CSII) and continuous glucose monitoring (CGM), and tested whether these changes, if any, were associated with glycated hemoglobin (HbA1c). Research Design and Methods: This prospective study investigated recently used CSII or CGM sites in 161 children and adolescents during the first year after initiation of a new diabetes device. Subcutaneous changes such as echogenicity, vascularization, and the distance from the skin surface to the muscle at CSII and CGM sites were assessed by ultrasound. Results: The distance from skin surface to muscle fascia at both the upper arm and abdomen was influenced by age, body mass index z-score, and sex. Especially in boys and the youngest, the depth of many devices outreached the mean distance. The mean distance for boys at the abdomen and upper arm ranged from 4.5-6.5 mm and 5-6.9 mm for all ages, respectively. Hyperechogenicity at CGM sites was 4.3% after 12 months. The frequency of subcutaneous hyperechogenicity and vascularization at CSII sites increased significantly over time (41.2% to 69.3% and 2% to 16% respectively, P < 0.001 and P = 0.009). Hyperechogenicity in the subcutis was not a predictor of elevated HbA1c (P = 0.11). Conclusion: There is large variation in the distance from the skin surface to the muscle fascia and many diabetes devices reach even deeper. Hyperechogenicity and vascularization increased significantly over time at CSII sites, but not CGM sites. The importance of hyperechogenicity for insulin absorption is unclear and further investigations are needed. Clinical Trial Registration number: NCT04258904.

The Injection Technique Factor: What You Don't Know or Teach Can Make a Difference

IN BRIEF To be consistently effective, insulin must be delivered into subcutaneous tissue. If insulin is delivered intramuscularly, its uptake and action become variably faster, leading to suboptimal, inconsistent glucose control. The best strategy to avoid intramuscular injection is to use the shortest needles available. Injection sites should be rotated systematically to prevent lipohypertrophy, which also substantially affects insulin uptake and action. New evidence-based insulin delivery recommendations are available, and awareness of them should lead to more effective use of insulin therapy, improved clinical outcomes, and considerable cost savings.

In vivo investigation of the tissue response to commercial Teflon insulin infusion sets in large swine for 14 days: the effect of angle of insertion on tissue histology and insulin spread within the subcutaneous tissue

OBJECTIVE

This study investigated the effects of the inflammatory tissue response (ITR) to an insulin infusion set (IIS) on insulin bolus spread over wear time, as well as the effect of cannula insertion angle on the ITR, bolus shape, and pump tubing pressure.

RESEARCH DESIGN AND METHODS

Angled or straight IISs were inserted every other day for 14 days into the subcutaneous tissue of 11 swine and insulin was delivered continuously. Prior to euthanasia, a 70 µL bolus of insulin/X-ray contrast agent was infused while recording a pressure profile (peak tubing pressure, p_max; area under the pressure curve, AUC), followed by the excision of the tissue-catheter specimen. Bolus surface area (SA) and volume (V) were assessed via micro-CT. Tissue was stained to analyze total area of inflammation (TAI) and inflammatory layer thickness (ILT) surrounding the cannula.

RESULTS

A bolus delivered through an angled IIS had a larger mean SA than a bolus delivered through a straight cannula (314.0±84.2 mm² vs 229.0±99.7 mm², p<0.001) and a larger volume (198.7±66.9 mm³ vs 145.0±65.9 mm³, p=0.001). Both decreased significantly over wear time, independent of angle. There was a significant difference in TAI (angled, 9.1±4.0 mm² vs straight, 14.3±8.6 mm², p<0.001) and ILT (angled, 0.7±0.4 vs straight, 1.2±0.7 mm, p<0.001). p_max (p=0.005) and AUC (p=0.014) were lower using angled IIS. As ILT increased, p_max increased, while SA and V decreased.

CONCLUSIONS

The progression of the ITR directly affected bolus shape and tubing pressure. Although straight insertion is clinically preferred, our data suggest that an angled IIS elicits lower grades of ITR and delivers a bolus with lower tubing pressure and greater SA and V. The subcutaneous environment plays a crucial role in IIS longevity, and the insertion angle needs to be considered in future IIS designs and clinical trials.

Competency of Prefilled Insulin Pen Usage Among Diabetes Patients in Saudi Arabia: A Cross-sectional Study

BACKGROUND

Correct insulin injection practice is essential for better diabetic control. The aim of this study is to investigate the level of competency of prefilled insulin pen usage (injection technique and storage) among diabetes patients in Saudi Arabia.

METHODS

A cross-sectional survey between March 2017 to July 2017 of randomly selected patients with diabetes attending Diabetes Treatment Center, Prince Sultan Military Medical City, Saudi Arabia, who are actively using a prefilled insulin pen, were interviewed to complete a pre-structured questionnaire to assess the competency of using the insulin pen. The contents of the questionnaire addressed the 6 competency components according to manufacturer recommendation (priming, count time, storage, using new needles, a store with no needles, and discard date), background, clinical and metabolic data. Results of the questionnaire were analyzed to identify common pitfalls and were also contrasted with background clinical and metabolic data.

RESULTS

165 patients with diabetes (aged 14-70yrs) were interviewed for the study and all questioners completed properly. Only 14 (8.5%) patients were following all of the six competency components. Count time 52 (31.6%) was the least followed competency component of the six, whereas discard date and storage of insulin pen were the most followed with 165 (100%) and 159 (96.4%), consecutively. Education was the only significant variable related to the following more than 3 of the competency components, and logistic regression showed the college or higher educated patients to be three times more likely follow more than 3 of the competency components.

CONCLUSION

The study concluded that majority of patients are either ignoring or unaware of the major components of correct use of prefilled insulin in Saudi Arabia.

Pediatric Insulin Injection Technique: A Multi-Country Survey and Clinical Practice Implications

INTRODUCTION

The 2015 Insulin Injection Technique Questionnaire survey involving 13,289 patients included 898 (6.8%) patients in the pediatric age range (≤ 18 years).

METHODS

The younger patients included in the questionnaire survey were grouped according to age: Group 1 (G1), 0-6 years, n = 85; Group 2(G2), 7-13, n = 423; Group 3 (G3), 14-18, n = 390. The injection technique was evaluated by means of a questionnaire and nurse assessment.

RESULTS

Nurses found lipohypertrophy at injection sites in 41.3, 45.2, and 47.3% of patients in G1, G2, and G3, respectively. Unexpected hypoglycemia was common, ranging from 23.8 to 48.1% of patients, and glucose variability was even more common (61.0% in G1, 45.9% in G2, and 52.5% in G3); both conditions were associated with lipohypertrophy. While increasing numbers of patients were using the recommended 4-mm needles, large percentages still used longer ones (33.3% in G1, 45.9% in G2, and 61.5% in G3). The reuse of needles was also common, ranging from 21.1 to 32.5% in the three age groups. Excessive reuse, defined as using a single needle more than five times, was reported by 9.4-21.8% of patients in the three age group. The percentages of patients who had not received any injection training in the last 12 months ranged from 21.2 to 26.8% in the three groups.

CONCLUSION

Implications of our study are as follows: (1) pediatric patients should use 4-mm pen needles or 6-mm syringes (inserted at a 45° angle); (2) patients aged ≤ 6 years should always inject into a raised skin fold regardless of which device is used; (3) all patients should rotate sites and use needles only once to avoid lipohypertrophy.

FUNDING

Becton-Dickinson (BD) diabetes care.

Ultrasound-guided measurement of skin and subcutaneous tissue thickness in children with diabetes and recommendations for giving insulin injections

Aim

To measure skin thickness (ST) and skin + subcutaneous layer thickness (SCT) by ultrasound and estimate the risk of intramuscular injection (IM) with different needle lengths across injection sites according to age group.

Method

Children recruited between 1 and 18 years with type 1 and 2 diabetes on insulin injections and divided into three age groups: 1–6 years, 7–12 years and 13–18 years. A portable ultrasound was used to measure ST and SCT at four injection sites on the abdomen, arm, thigh and buttock.

Results

Total 153 children enrolled for the study. The mean (SD) measurement of ST & SCT at four sites on abdomen, arm, thigh & buttocks were as follows; 4.33 mm (±2.22), 5.55 mm (±2.26), 5.83 mm (±3.12), 6.48 mm (±3.47) in 1–6 years old; 7.11 mm (±3.68), 7.79 mm (±4.54), 7.17 mm (±3.62), 8.51 mm (±3.65) in 7–12 years old; 8.94 mm (±4.50), 8.42 mm (±5.00), 8.61 mm (±4.76), 9.76 mm (±4.38) in 13–18 years old. Young children, 1–6 years have the highest risk of IM injection with all needle lengths, i.e. 4, 5, 6, 8 & 12.7 mm, while older children 7–12 & 13–18 years have a lower risk with shorter needles (4, 5 and 6 mm) as compared to longer needles (8 and 12.7 mm).

Conclusions

Children with diabetes on insulin therapy should be advised on the appropriate needle length accordingly to their age and BMI.

Forum for Injection Technique and Therapy Expert Recommendations, India: The Indian Recommendations for Best Practice in Insulin Injection Technique, 2017

Health-care professionals in India frequently manage injection or infusion therapies in persons with diabetes (PWD). Patients taking insulin should know the importance of proper needle size, correct injection process, complication avoidance, and all other aspects of injection technique from the first visit onward. To assist health-care practitioners in their clinical practice, Forum for Injection Technique and Therapy Expert Recommendations, India, has updated the practical advice and made it more comprehensive evidence-based best practice information. Adherence to these updated recommendations, learning, and translating them into clinical practice should lead to effective therapies, improved outcomes, and lower costs for PWD.

New Insulin Delivery Recommendations

Many primary care professionals manage injection or infusion therapies in patients with diabetes. Few published guidelines have been available to help such professionals and their patients manage these therapies. Herein, we present new, practical, and comprehensive recommendations for diabetes injections and infusions. These recommendations were informed by a large international survey of current practice and were written and vetted by 183 diabetes experts from 54 countries at the Forum for Injection Technique and Therapy: Expert Recommendations (FITTER) workshop held in Rome, Italy, in 2015. Recommendations are organized around the themes of anatomy, physiology, pathology, psychology, and technology. Key among the recommendations are that the shortest needles (currently the 4-mm pen and 6-mm syringe needles) are safe, effective, and less painful and should be the first-line choice in all patient categories; intramuscular injections should be avoided, especially with long-acting insulins, because severe hypoglycemia may result; lipohypertrophy is a frequent complication of therapy that distorts insulin absorption, and, therefore, injections and infusions should not be given into these lesions and correct site rotation will help prevent them; effective long-term therapy with insulin is critically dependent on addressing psychological hurdles upstream, even before insulin has been started; inappropriate disposal of used sharps poses a risk of infection with blood-borne pathogens; and mitigation is possible with proper training, effective disposal strategies, and the use of safety devices. Adherence to these new recommendations should lead to more effective therapies, improved outcomes, and lower costs for patients with diabetes.

Needle detachment in a slim and physically active child with insulin pump treatment

Insulin pump therapy (CSII) is well established in pediatric patients with type 1 diabetes. In childhood diabetes, insulin pump treatment shows considerable advantages such as fewer injections, increased flexibility, fewer hypoglycemic events and lower HbA1c levels. Side effects such as catheter obstruction, technical pump failure, and dermatological complications have been observed, but are rarely reported. The reported patient is a physically very active and slim 10-year-old boy with reduced subcutaneous fatty tissue. After strong muscular activity an accidental rupture of the infusion set and needle detachment occurred in October 2013. X-ray and ultrasound imaging localized the needle in the musculus rectus femoris dexter. The needle was kept in situ and oral antibiotic treatment to prevent inflammatory reaction was prescribed. Repeated ultrasound measurements documented that the needles position had remained unchanged. Steel needle catheters (Sure-T infusion set, 6 mm) positioned in a thin layer of subcutaneous fat tissue of the thigh, combined with intense sports activity can result in a needle rupture and penetration into the muscle. Careful monitoring provides an alternative to surgery and lowers the risk of muscular necrosis. Because of differences in the distribution of subcutaneous fat tissue, an individualized catheter selection is necessary in pump treatment for children and adolescents, requiring a variety of different catheter sets.

Injection Technique and Pen Needle Design Affect Leakage From Skin After Subcutaneous Injections

BACKGROUND

After a subcutaneous injection fluid might leak out of the skin, commonly referred to as leakage or backflow. The objective was to examine the influence of needle design and injection technique on leakage after injections in the subcutaneous tissue of humans and pigs.

METHOD

Leakage data were obtained from a post hoc analysis of clinical trial data and from a pig study. Data from the clinical study were used to determine leakage as a function of injection volume, speed and region. Data from the pig study were used to determine leakage as a function of needle wall thickness, needle taper, injection angle, and wait time from end of injection to withdrawal of needle from skin.

RESULTS

Leakage volume was positively related to injection volume. Injections in the abdomen caused less leakage than thigh injections. A 32G needle caused less leakage than a 31G and a 32G tip (tapered) needle, and a "straight in" 90° needle insertion angle caused less leakage than an angled (~45°) insertion. Wait times of minimum 3 seconds caused less leakage than immediate withdrawal of the needle after injection. Needle wall thickness and injection speed did not influence leakage.

CONCLUSIONS

Leakage will be minimized using a thin needle, using 90° needle insertion in the abdomen, injecting maximum 800 µL at a time, and waiting at least 3 seconds after the injection until the needle is withdrawn from the skin.

Can the upper inner side of the thigh become a new option for insulin injection?

OBJECTIVE

Sites for subcutaneous insulin injections include the upper arms, abdomen, buttocks and outer sides of the thigh. No similar study has explored the feasibility of using the inner side of the thigh for insulin injection, since the 4 mm pen needles were introduced for clinical use. This study aimed to determine whether the inner side of the thigh is suitable for insulin injection.

RESEARCH DESIGN AND METHODS

Seventy-five patients with diabetes under insulin therapy from the Inpatient Department of Endocrinology were recruited for this non-blinded, non-randomized observational study. Subcutaneous adipose layer thicknesses of the upper, middle and lower area of the inner and outer thighs of 35 patients were measured by ultrasound, distance from the skin surface to the femoral deep vessels in 20 patients was measured, and insulin was injected at the upper inner and outer sides of the thigh in 20 patients. Pain perception, bleeding or bruising, leakage at the injection sites, blood glucose changes after insulin injection, and preferred ratings of the patients were measured.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov NCT02307968.

RESULTS

Subcutaneous adipose layer thicknesses at both the upper inner and outer thighs were more than 4 mm and the minimum distance was 10 mm. Among the 100 injections at the upper inner thigh, only three incidents of perceived pain occurred. No bleeding or bruising and leakage were observed from the inner or outer sides. Furthermore, the difference in blood glucose control between insulin injections at the inner side and outer sides was not statistically significant. Patient ratings for injections at the inner side were similar to injections at the outer side. The key limitation of this study was the small sample size of adult patients as well as the non-randomized controlled design of this study.

CONCLUSION

The upper inner thigh might be a new option for insulin injection rotation.

Intramuscular risk at insulin injection sites--measurement of the distance from skin to muscle and rationale for shorter-length needles for subcutaneous insulin therapy

BACKGROUND

Intramuscular (IM) injection can increase insulin absorption, causing hypoglycemia. Available needle lengths today are 4-12.7 mm for pens and 6-12.7 mm for syringes. We describe the distance (D) from skin surface to muscle fascia at injection sites for subcutaneous (SC) insulin therapy and recommend needle lengths to reduce IM injection risk.

MATERIALS AND METHODS

At two locations in the United States, skin and SC fat thicknesses were measured by ultrasound at the abdomen, arm, thigh, and buttock in diverse adults (body mass index [BMI] range, approximately 19-65 kg/m²) with diabetes (n=341 with one or more paired skin and SC measurement, permitting calculation of D). The natural log of D by body site, BMI, and gender were analyzed using a mixed model to estimate IM risk.

RESULTS

D varied significantly by body site, BMI, and gender (each P<0.001), increasing with higher BMI and in women. Median D ranged from 10.9 mm (95% confidence interval, 10.3, 11.6) at the thigh to 16.9 mm (15.9, 18.1) at the buttock. Minimum D was <3 mm at the thigh and <5 mm elsewhere. When inserted 90° without pinch-up, the most commonly used needle worldwide (8 mm) has estimated IM risks of 25% and 9.7%, respectively, in the thigh and abdomen, versus 1.6% and 0.1%, respectively, with a 4 mm needle. A 45° insertion reduces, but does not eliminate, IM risk with longer needles.

CONCLUSIONS

Gender, BMI, and body site affect D; when combined with needle length and insertion angle, these factors permit detailed estimates of IM insulin injection risk. Such risk varies across sites, appears greatest at the thigh, is unnecessarily increased with 8 mm and 12.7 mm needles, and is greatly reduced with shorter-length needles and good injection technique.

Poorer glycaemic control is associated with increased skin thickness at injection sites in children with type 1 diabetes

We aimed to assess the association between skin thickness and glycaemic control in children with type 1 diabetes. Forty-five children (51% males) aged 10.5 ± 2.1 years were studied. Thickness of skin layers were determined by ultrasonography, with participants having ultrasound scans of three anatomical regions (abdomen, thigh, and buttocks). Poorer glycaemic control (increasing HbA1c values) was associated with greater thickness of the dermis (p = 0.015), with an estimated thickening of 87 μm with every 1% increase in HbA1c. Our data suggest that dermal changes associated with poorer glycaemic control in adults are also observed in childhood.

Effects of age, gender, BMI, and anatomical site on skin thickness in children and adults with diabetes

Objective

We aimed to assess the effects of age, sex, body mass index (BMI), and anatomical site on skin thickness in children and adults with diabetes.

Methods

We studied 103 otherwise healthy children and adolescents with type 1 diabetes aged 5–19 years, and 140 adults with type 1 and type 2 diabetes aged 20–85 years. The thicknesses of both the dermis and subcutis were assessed using ultrasound with a linear array transducer, on abdominal and thigh skin.

Results

There was an age-related thickening of both dermis (p<0.0001) and subcutis (p = 0.013) in children and adolescents. Girls displayed a substantial pubertal increase in subcutis of the thigh (+54%; p = 0.048) and abdomen (+68%; p = 0.009). Adults showed an age-related decrease in dermal (p = 0.021) and subcutis (p = 0.009) thicknesses. Pubertal girls had a thicker subcutis than pubertal boys in both thigh (16.7 vs 7.5 mm; p<0.0001) and abdomen (16.7 vs 8.8 mm; p<0.0001). Men had greater thigh dermal thickness than women (1.89 vs 1.65 mm; p = 0.003), while the subcutis was thicker in women in thigh (21.3 vs 17.9 mm; p = 0.012) and abdomen (17.7 vs 9.8 mm; p<0.0001). In boys, men, and women, both dermis and subcutis were thicker on the abdomen compared to thigh; in girls this was only so for dermal thickness. In both children and adults, the skin (dermis and subcutis) became steadily thicker with increasing BMI (p<0.0001).

Conclusions

Skin thickness is affected by age, pubertal status, gender, BMI, and anatomical site. Such differences may be important when considering appropriate sites for dermal/subcutaneous injections and other transdermal delivery systems.

Ditch the pinch: bilateral exposure injuries during subcutaneous injection

BACKGROUND

Subcutaneous injection into an elevated skin fold poses a risk of "bilateral exposure" injury whereby the needle pierces the opposite side of a skin fold and subsequently enters the tissue of the health care worker (HCW).

METHODS

Retrospective review was conducted examining the Exposure Prevention Information Network (EPINet) needlestick surveillance data. Data from 2,402 injuries occurring during subcutaneous injection were included for analysis. Descriptive data, statistical comparisons, and a logistic regression model reporting relative risk are provided.

RESULTS

Eighty-five bilateral exposure injuries were identified between 2000 and 2009, representing 3.5% (n/N=85/2,402) of all injection-related percutaneous injuries. 65.4% Of the variance in bilateral exposure injury occurrence is explained through examination of the following: (1) manual elevation ("pinching") subcutaneous tissue prior to injection; (2) thin/emaciated patient; (3) injection of insulin; (4) injection of heparin; (5) injection of enoxaparin (Lovenox); (6) if a safety device was used; and (7) whether the health care worker was wearing gloves at the time of the injury (χ(2)7 = 424.2; P<.01).

CONCLUSION

Manual tissue elevation should be avoided to minimize the risk of bilateral exposure injuries.

Skin and subcutaneous thickness at injecting sites in children with diabetes: ultrasound findings and recommendations for giving injection

BACKGROUND

Children who inject insulin need clear guidelines as to the length of needle best for them. We studied the distance from surface to muscle in children in order to make needle choices which are evidence-based.

METHODS

One hundred one children with type 1 diabetes were divided into three groups according to age: 2-6, 7-13, and 14-17 yr. The thickness of skin and subcutaneous (SC) tissue was measured by ultrasound in all injection sites.

RESULTS

Skin thickness varied from 1.58 mm in the arm of the youngest children to 2.29 mm in the buttocks of the adolescents. Values decreased progressively based on age (2-6 < 7-13 < 14-17) and on body site (arm < thigh < abdomen < buttocks). Skin + SC thickness varied in a similar fashion. The skin surface to muscle distances were <4 mm in nearly 10% of children, especially in the 2-6 yr group. In this group, the rate of intramuscular (IM) injections using the 4-mm pen needle when a pinch-up is not used would be 20.2%. This rate of IM injections doubles when using the 5-mm needle, and when injections are given under similar conditions it triples using the 6-mm needle.

CONCLUSIONS

It seems medically appropriate for all children to use short needles where possible to minimize inadvertent IM injections which may increase glycemic variability. Currently, the safest needle for all children appears to be the 4-mm pen needle. However, when used in children aged 2-6 yr, it should be used with a pinched skin fold.

Translating the research in insulin injection technique: implications for practice

PURPOSE

Glucose variability leading to suboptimal glycemic control is common among people using injection therapies. Advanced technology and new studies have identified important issues related to injection technique: needle length and gauge, body mass index, skin and subcutaneous tissue thickness, adequate resuspension of cloudy insulins, leakage, choice of injection site and rotation, pinching a skinfold, and lipohypertrophy. All these issues can affect pain and bruising, insulin absorption, and blood glucose levels. The purpose of this article is to review current and past research regarding insulin injection therapy and to provide practical, translational information regarding injection technique, teaching/learning techniques specific to insulin administration, and implications for diabetes self-management education and support.

CONCLUSION

International injection recommendations for patients with diabetes have recently been published and have identified specific recommendations for health care professionals. This article provides an evidence-based translational and practical review of the research regarding injection technique and teaching/learning theory. Diabetes educators need to reevaluate how they provide instruction for the administration of insulin and other injectable medications. Research regarding skin and subcutaneous thickness reveals that shorter needles may be appropriate for the majority of patients regardless of body mass index. Periodic reassessment of injection technique, including suspension of cloudy insulins and inspection of injection sites for lipohypertrophy, is a critical aspect of the role of the diabetes educator. An injection checklist is provided as a guide for diabetes educators.

The role of comfort and discomfort in insulin therapy

Despite the recognized importance of optimal insulin therapy, patient adherence to insulin therapy is an ongoing clinical care challenge. Insulin omission continues to be frequent and underestimated and has been correlated with poorer glycemic control and increased rates of diabetes-related complications. Insulin users consistently identify multiple factors that contribute to insulin injection-related anxiety and to non-adherence. Injection-related discomfort continues to bear a significant contribution. Over the last decade, with advances in needle manufacturing technology, shorter and narrower needles have been associated with progressively improving patient self-rating of injection discomfort. Consequently, patient surveys of insulin users show discomfort to rank in the bottom third of significant contributors by prevalence. However, healthcare providers (HCP) and family member care providers continue to demonstrate a high level of anticipated and perceived pain for the patient. HCP anxiety and pain anticipation are each associated with patient anxiety and may therefore play a significant contributing role in patient non-adherence.

Addressing barriers to insulin therapy: the role of insulin pens

Despite the fundamental role of insulin therapy in diabetes management, many patients and some clinicians may resist insulin initiation due to concerns about its complexity or a general resistance to injections. Many patients' concerns about insulin initiation may stem from perceptions about the pain and inconvenience of using vials and syringes for delivering insulin. However, insulin pen devices offer an easier method for insulin administration that is more accurate, less painful, and more discreet compared with vials and syringes. Advances in insulin pen technology have enhanced their utility by increasing their accuracy, reducing the injection force required, and incorporating mechanisms to store the dose, time, and date of previous insulin injections. Substantial evidence demonstrates that insulin pen devices are preferred by both patients and clinicians and have the potential to improve adherence, enhance quality of life, reduce the risk of hyperglycemia, and decrease costs. Ultimately, the advantages of insulin pens may reduce resistance to initiating and adhering to insulin therapy. Because insulin pens are underused in the United states compared with in other countries, it is critical that clinicians understand the potential benefits of insulin pens and communicate them to their patients.

Insulin administration: selecting the appropriate needle and individualizing the injection technique

INTRODUCTION

Patients with diabetes who receive insulin therapy often fail to meet their targets for metabolic control with insulin injections. Their inadequate glycemic control may be related to incorrect injection procedure.

AREAS COVERED

This review examines the latest data related to insulin injection and needle characteristics, which play an integral role in patient satisfaction. Searches of Medline and Cumulative Index to Nursing and Allied Health Literature databases were conducted. Results show that optimal insulin injection can facilitate glycemic control in pediatric and adult patients. In general, needles shorter than 8 mm are appropriate for normal weight, obese pediatric and adult patients. However, body mass index, gender, race, age and injection site can influence the depth of subcutaneous tissue and thus, the desired needle size and injection technique. Although the abdomen, thighs and buttocks are all recommended injection sites, abdominal injections disperse insulin slightly more rapidly than thigh injections.

EXPERT OPINION

Wider acceptance of needles shorter than 6 mm will occur with more evidence of their safety and efficacy, particularly in children. Development of shorter and thinner needles to make injections even easier and less burdensome may be expected in the future.

New injection recommendations for patients with diabetes

AIM

Injections administered by patients are one of the mainstays of diabetes management. Proper injection technique is vital to avoiding intramuscular injections, ensuring appropriate delivery to the subcutaneous tissues and avoiding common complications such as lipohypertrophy. Yet few formal guidelines have been published summarizing all that is known about best practice. We propose new injection guidelines which are thoroughly evidence-based, written and vetted by a large group of international injection experts.

METHODS

A systematic literature study was conducted for all peer-reviewed studies and publications which bear on injections in diabetes. An international group of experts met regularly over a two-year period to review this literature and draft the recommendations. These were then presented for review and revision to 127 experts from 27 countries at the TITAN workshop in September, 2009.

RESULTS

Of 292 articles reviewed, 157 were found to meet the criteria of relevance to the recommendations. Each recommendation was graded by the weight it should have in daily practice and by its degree of support in the medical literature. The topics covered include The Role of the Professional, Psychological Challenges, Education, Site Care, Storage, Suspension and Priming, Injecting Process, Proper Use of Pens and Syringes, Insulin analogues, Human and Pre-mixed Insulins, GLP-1 analogs, Needle Length, Skin Folds, Lipohypertrophy, Rotation, Bleeding and Bruising, Pregnancy, Safety and Disposal.

CONCLUSION

These injecting recommendations provide practical guidance and fill an important gap in diabetes management. If followed, they should help ensure comfortable, effective and largely complication-free injections.

Survey of insulin site rotation in youth with type 1 diabetes mellitus

OBJECTIVE

Injection site rotation is an important component of insulin administration and is helpful in preventing lipodystrophy in type 1 diabetes (T1DM). We examined the number of injection/infusion sites (sites) used by youth with T1DM and their perceived barriers to using new sites for insulin.

METHODS

Two hundred and one youth with T1DM completed a 24-item survey about site rotation practices and barriers to site rotation during a routine diabetes appointment.

RESULTS

Fifteen percent of youth reported using at least four distinct sites in their rotation plan, while 22% reported using only one site. A negative correlation was found between number of sites used and the number of perceived barriers endorsed by youth on multiple daily injections. Fear of pain was the most common barrier endorsed by youth.

CONCLUSION

Many youth with T1DM may not adhere to an adequate site rotation plan. Regular assessment of insulin sites and counseling regarding adequate site rotation is needed when managing diabetes in youth. Relaxation and distraction may help to reduce youths' fear of pain when rotating to new insulin sites.

Defining the ideal injection techniques when using 5-mm needles in children and adults

OBJECTIVE

We aimed to establish the ideal injection techniques using 5-mm needles to reliably inject insulin into the subcutaneous fat in both children and adults and to quantify the associated pain and leakage of the test medium.

RESEARCH DESIGN AND METHODS

A total of 259 subjects (122 children/adolescents and 137 adults) were injected with sterile air corresponding to 20 IU insulin (200 microl) with 32-G 5-mm needles at 90 degrees or 45 degrees , in the abdomen and thigh, and with or without a pinched skin fold. Injection depth was assessed via ultrasonography. Subjects rated pain on a visual analog scale. Test medium injections into the abdomen and thigh (0.2-0.6 ml) were also administered to assess injection leakage.

RESULTS

Among children, 5.5% of injections were intramuscular (IM) and 0.5% were intradermal, while in adults, the incidence was 1.3 and 0.6%, respectively. The frequency of IM injections was greater in boys and negligible among adult women. Subcutaneous fat thickness was the primary predictor of the likelihood of IM injections (P < 0.001). A third of all patients reported experiencing no pain during insulin injection, with children/adolescents experiencing considerably more discomfort than adults. Some leakage of medium was observed, but was unrelated to injection volume and was generally minimal.

CONCLUSIONS

5-mm needles are reliably inserted into subcutaneous fat in both adults and children. These needles were associated with reduced pain and minimal leakage. We recommend an angled injection with a pinched skin fold for children, while in adults, the technique should be left to patient preference.

Insulin leakage value in relation to pen needle length and administered dose after subcutaneous injection

OBJECTIVE

During a subcutaneous injection with commonly used pen needles, the safety of drug administration plays an essential role. Today short needles with a length of 5.0 mm are increasingly being used. However, so far it is unresolved whether short needles of <5.0 mm affect the safety of insulin injections because of an increased backflow to the skin surface. We examined the influence of needle length and administered insulin dosage on the insulin backflow and the distribution of human insulin in the tissue by a quantitative determination of the amount of backflow of insulin to the skin surface. For the first time a new 4.5-mm pen needle was examined for its administration safety.

RESEARCH DESIGN

Human insulin was radioactively marked. By means of an insulin pen different insulin dosages with pen needles of different lengths into fresh pork rind (ex vivo model) were administered. The amount of the marked insulin leaking from the tissues at the injection site was covered and absorbed immediately into a cotton swab. The amount of leakage was calculated by means of the radioactivity taken up by the swab.

RESULTS

The amount of leakage for each measurement was less than 1% of the total dosage administered. The amount of leakage increased with increased dosage administered in absolute terms, but expressed as a percentage of the increased dosage administered the leakage decreased.

CONCLUSION

The needle length (between 12 mm and 4.5 mm) did not have a meaningful influence on the amount of leakage; however, significant differences with different needle lengths could be observed.

Comparative glycemic control, safety and patient ratings for a new 4 mm x 32G insulin pen needle in adults with diabetes

OBJECTIVE

Pen needles (PN) for subcutaneous insulin therapy have become smaller; 5 mm PNs are now the shortest in use. We evaluated the safety, efficacy and patient ratings of a new 4 mm x 32 gauge (G) PN.

RESEARCH DESIGN AND METHODS

Subjects with type 1 and type 2 diabetes and HbA1c 5.5% to 9.5% participated in a randomized non-inferiority cross-over trial, at four U.S. centers. Subjects used 4 mm x 32G PNs and either 5 mm x 31G PNs (4/5 mm) or 8 mm x 31G PNs (4/8 mm) in two, 3-week treatment periods; order of needle use was controlled. Subjects were either 'low dose' or 'regular dose' users (highest single insulin dose <or= 20 units and 21-40 units, respectively). Percent absolute change in serum fructosamine (% |Delta Fru|) was the primary endpoint; unexplained, severe hypo- or hyperglycemia was a secondary measure. Leakage at injection sites and pain measured by visual analog scale were tertiary measures. Equivalent glycemic control was defined á priori as % |Delta Fru| (including 95% CI) within 20%; 40 subjects per subgroup provides 90% power at alpha = 0.05.

CLINICAL TRIAL REGISTRATION

The study was registered on clinicaltrials.gov (identifier: NCT00928057).

RESULTS

Of 173 subjects randomized, 168 completed the study, and 163 were included in the fructosamine analyses--83 and 80 in the 4/5 mm and 4/8 mm groups, respectively. Subjects were 56% male, mean 52.6 yrs, 63% type 2. Baseline HbA1c = 7.5 +/- 1.0% and fructosamine 301 +/- 55.1 micromol/L. Mean % |Delta Fru| was 4.9% (95% CI 3.8, 6.0) and 5.5% (4.5, 6.4), respectively, for the 4/5 mm and 4/8 mm groups, meeting glycemic equivalence criteria; results were similar in both dose groups. The median |Delta Fru| was 11.0 micromol/L (8.0, 13.0) and 13.5 micromol/L (9.8, 18.0) for the 4/5 mm and 4/8 mm groups, respectively. Unexplained, severe hypo- and hyperglycemic episodes were infrequent and not different between PNs. The 4 mm PN was rated significantly less painful and preferred by approximately 2/3 of subjects (p < 0.01). All three PNs had similar reported injection site leakage.

LIMITATIONS

The study was of relatively short duration, in adults in the U.S. Further trials in other patients (e.g., GLP-1 users, pediatrics, obese) should be performed.

CONCLUSIONS

The 4 mm x 32G PN provided equivalent glycemic control compared to 31G, 5 mm and 8 mm PNs with reduced pain, no difference in insulin leakage and was preferred by patients.

Skin and subcutaneous adipose layer thickness in adults with diabetes at sites used for insulin injections: implications for needle length recommendations

OBJECTIVE

During subcutaneous insulin therapy, inadvertent intramuscular (IM) injections may increase pain and/or adversely affect glucose control. The most appropriate needle length for patients depends on skin thickness (ST) and the distance to muscle fascia. ST and subcutaneous adipose layer thickness (SCT) were measured in adults with diabetes.

RESEARCH DESIGN AND METHODS

A total of 388 US adults with diabetes (in three BMI subgroups: <25, 25-29.9, and >or=30 kg/m(2)) with diverse demographic features were evaluated. Each subject had ultrasound measurements of ST and SCT at four injection sites.

RESULTS

Subjects had BMI 19.4-64.5 kg/m(2), age 18-85 years; 40% Caucasian, 25% Asian, 16% Black, 14% Hispanic; 28% type 1 diabetes. Mean ST (+/-95% CI) was: arm 2.2 mm (2.2, 2.3), thigh 1.9 mm (1.8, 1.9), abdomen 2.2 mm (2.1, 2.2) and buttocks 2.4 mm (2.4, 2.5). Multivariate analyses showed body site, gender, BMI, and race are statistically significant factors for ST but effects were small. Thigh ST was <0.6 mm thinner than the buttocks. Differences of 10 kg/m(2) account for 0.2 mm ST variation. Mean SCT was: arm 10.8 mm (10.2, 11.3), thigh 10.4 mm (9.8, 10.9), abdomen 13.9 mm (13.2, 17.7) and buttocks 15.4 mm (14.7, 16.2). Females had 5.1 mm greater SCT. Differences of 10 kg/m(2) account for 4 mm SCT variation.

ADVERSE EVENTS

A few mild hypo- or hyperglycemia events, unrelated to study procedure, were detected and treated before subject discharge from study visits.

LIMITATIONS

Only adults in the US were studied; some measurements could not be obtained on every subject, at every injection site.

CONCLUSIONS

Injection site ST does not differ by clinically significant degrees in demographically diverse adults with diabetes; SCT has a wider range. Needles >or=8 mm, inserted perpendicularly, may frequently enter muscle in limbs of males and those with BMI <25 kg/m(2). With 90 degrees insertion, needles 4-5 mm enter the subcutaneous tissue with minimal risk of IM injection in virtually all adults. These data will assist recommending appropriate length needles for subcutaneous insulin injections in adults.