A systematic review of measures for reducing injection pain during adult immunization

Massaging as a pain-relieving intervention before performing intravenous access

PURPOSE

Pain is "an unpleasant sensory and emotional experience arising from actual or potential tissue damage or described in terms of damage". Stimulating the skin by rubbing, stroking, massaging, or applying pressure near the injection site is pain-relieving. Needle-related procedures induce anxiety, distress, and fear in children and adults. The present study aimed to test the effectiveness of massaging the access site in reducing pain associated with intravenous access.

DESIGN

After obtaining institutional ethics committee approval, this prospective randomized single-blinded study was performed on 250 ASA I-II patients 18 to 65 years old, scheduled for elective minor general surgery under general anaesthesia.

METHODS

Patients were randomized into the Massaging Group (MG) and the Control Group (CG). A Situational Trait Anxiety Inventory (STAI) was conducted to evaluate the anxiety levels of the patients. In addition, the skin adjacent to the intravenous access site was massaged for 15 s in circular motions with moderate intensity by the investigator's right thumb before performing the intravenous access in the MG. The CG did not receive any massage adjacent to the access site. The primary endpoint, the intensity of perceived pain, was rated on a non-graduated 10-cm Visual Analogue Score (VAS).

FINDINGS

The groups' demographic data and STAI I-II scores were similar. There was a significant difference between the VAS scores of the two groups (p < 0.05).

CONCLUSIONS

Our results support massaging as an effective pain-relieving technique before intravenous intervention. As massaging is a universal and non-invasive intervention that requires no advanced preparation, we recommend massaging before each intravenous cannulation to reduce pain caused by intravenous access.

Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks-American Pain Society-American Academy of Pain Medicine Pain Taxonomy Diagnostic Criteria for Acute Needle Pain

Needle procedures are among the most common causes of pain and distress for individuals seeking health care. While needle pain is especially problematic for children needle pain and associated fear also has significant impact on adults and can lead to avoidance of appropriate medical care. Currently there is not a standard definition of needle pain. A taxonomy, or classification system, for acute needle pain would aid research efforts and enhance clinical care. To meet this need, the Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks public-private partnership with the U.S. Food and Drug Administration, the American Pain Society, and the American Academy of Pain Medicine formed the Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks-American Pain Society-American Academy of Pain Medicine Pain Taxonomy initiative. One of the goals of this initiative was to develop taxonomies for acute pain disorders, including needle pain. To accomplish this, a working group of experts in needle pain was convened. Based on available literature and expert opinion, the working group used a 5-dimenional structure (diagnostic criteria, common features, modulating factors, impact and/or functional consequences, and putative mechanisms) to develop an acute pain taxonomy that is specific needle pain. As part of this, a set of 4 diagnostic criteria, with 2 modifiers to account for the influence of needle associated fear, are proposed to define the types of acute needle pain. PERSPECTIVE: This article presents a taxonomy for acute needle pain. This taxonomy could help to standardize definitions of acute pain in clinical studies of patients undergoing needle procedures.

Effectiveness of physical stimulation for reducing injection pain in adults receiving intramuscular injections: a systematic review and meta-analysis

OBJECTIVE

The objective of this review was to synthesize the best available research evidence regarding the effectiveness of physical stimulation for reducing injection pain in adults receiving intramuscular injections.

INTRODUCTION

Pain associated with intramuscular injections continues to be a challenge for nurses. Various physical stimulation methods to alleviate pain and improve satisfaction for patients receiving intramuscular injections have been reported; however, the evidence surrounding the effectiveness of these methods remains inconclusive.

INCLUSION CRITERIA

This systematic review considered randomized and quasi-experimental studies that used any physical stimulation strategies (eg, skin tapping, manual pressure, massage, pinch, traction) for adults aged 18 years and over receiving intramuscular injections. Studies that evaluated pain using validated instruments were considered for inclusion.

METHODS

A three-step search strategy was conducted. MEDLINE, Embase, CINAHL, the Cochrane Library (Cochrane CENTRAL), Google Scholar, Dissertation Abstracts International, ProQuest Dissertations and Theses, and MedNar were searched from inception until 2020. We restricted the inclusion of studies to trials published in English. Two independent reviewers conducted the critical appraisal of eligible studies using the JBI checklists for randomized controlled and quasi-experimental trials. Data were extracted using the JBI data extraction tool, and meta-analysis and subgroup analysis were undertaken, where appropriate.

RESULTS

Twenty-five studies were included with a total sample size of 1956 patients. Pooled results demonstrated that pain was significantly less with the use of the Helfer skin tap technique compared to no intervention (two studies; RR 0.73; 95% CI 0.66, 0.81; P <0.00001) or standard intervention (three studies; SMD -2.25; 95% CI -3.65, -0.85; P =0.002). Intervention with acupressure using standard treatment as control showed significant reduction in pain intensity (MD -4.78; 95% CI -5.32, -4.24; P <0.00001). Similarly, pain was significantly lower with manual pressure (two studies; SMD -0.42; 95% CI -0.69, 0.15; P =0.002) when compared to standard treatment. Pain scores were significantly lower in patients who received pinch technique, ShotBlocker, massage, or combination intervention (skin traction, pressure, and rapid muscle release) compared with no intervention, standard treatment, or placebo control.

CONCLUSIONS

The evidence from this review demonstrates that physical stimulation - particularly the Helfer skin tap technique, acupressure, manual pressure, pinch technique, ShotBlocker, massage, and combination - can significantly lower intramuscular injection pain; however, this is based on low or very low certainty of evidence.

SYSTEMATIC REVIEW REGISTRATION NUMBER

PROSPERO CRD42020168586.

Effectiveness of physical stimulation on injection pain in adults receiving intramuscular injections: a systematic review protocol

OBJECTIVE

The objective of this review is to evaluate the effectiveness of physical stimulation on injection pain in adults receiving intramuscular injections.

INTRODUCTION

Intramuscular injections are the most commonly used modality for administration of pharmacological treatments. Despite this, pain from intramuscular injections is the most commonly reported side effect. Reducing patients' pain from intramuscular injections is important; however, the challenge is in selecting from the current methods available to alleviate pain, which are varied. The findings of this review may identify the most effective physical stimulation method to reduce the side effect of pain from an intramuscular injection.

INCLUSION CRITERIA

This review will consider studies that include adults aged 18 years and over that use physical stimulation interventions during intramuscular injections. Any physical stimulation strategies used during intramuscular injections including devices, skin tapping, manual pressure, massage, pinch, and traction will be considered. Studies that evaluate pain using validated tools such as pain scales will be included.

METHODS

The review will undertake to find both published and unpublished studies. The key information sources to be searched are MEDLINE, Embase, CINAHL, the Cochrane Library, Cochrane Central Register of Controlled Trials, Google Scholar, Dissertation Abstracts International, ProQuest Dissertations and Theses, and MedNar. Two independent reviewers will conduct a critical appraisal of eligible studies, assess the methodological quality, and extract the data. Studies will, where possible, be pooled in a statistical meta-analysis.

SYSTEMATIC REVIEW REGISTRATION NUMBER

PROSPERO CRD42020168586.

The effectiveness of vibratory stimulation in reducing pain in children receiving vaccine injection: A randomized controlled trial

BACKGROUND

Although vaccine injections are important, children experience pain and discomfort upon their administration. BUZZY®, a vibratory stimulation tool with an ice pack, was reported to be an effective tool for reducing the pain caused to children during injection administration; its mechanisms were explained by gate control theory. However, the evidence is inadequate because of insufficient methodology in previous reports. Therefore, we aimed to assess whether the application of vibration would significantly reduce children's pain during vaccine injections.

METHODS

A single-blind randomized controlled trial recruiting children aged ≤6 years who were receiving vaccine injections was conducted between August and December 2019. If the children's parents consented to their participation, BUZZY® was attached to the child's arm prior to vaccination. BUZZY® was switched on before injection in the intervention group but not in the control group. The vaccination procedure was recorded, and researchers and parents assessed each child's pain using validated pain scales. Researchers conducted their assessment using video data to ensure blinding. Parents were administered a questionnaire after the children's vaccination. Data were analyzed using the t-test or chi-square test.

RESULTS

We analyzed 118 children (intervention group = 62, control = 56). No between-group difference was observed according to the researchers' assessment (mean score = 6.98 and 7.63, respectively; p = 0.25); however, a significant difference was found based on the parents' assessment (mean score = 7.39 versus 8.46; p = 0.02). Most responses received to open-ended questions were positive comments for this study.

CONCLUSIONS

We revealed that the effect of vibration is not significant in reducing vaccine injection pain among children. Further studies are needed to examine the other components of BUZZY®, which include its cooling effect, and the effect of BUZZY® itself in terms of whether children will undergo vaccination without resistance and have reduced trauma related to vaccination.

Understanding parents' use of a knowledge translation tool to manage children's vaccination pain

Supplemental Digital Content is Available in the Text.

The relevance of KT tools, and parents' confidence in using them, was related to uptake of vaccination pain management strategies for children.

Introduction:

Although several evidence-based strategies for managing children's vaccination pain exist, many parents report being unaware of them. Knowledge translation (KT) tools present evidence-based information in plain language.

Objectives:

This two-phase study assessed parents/caregivers' uptake of evidence-based pain management strategies via a KT tool and considered factors related to parents' planned, actual, and future use of these strategies.

Methods:

In phase 1, parents were exposed to an online KT tool on physical, psychological, and pharmacological vaccination pain management strategies, and their impressions were assessed by questionnaires including the Information Assessment Method for Parents. In phase 2, after vaccination, parents completed a follow-up survey on their uptake and experiences using the information.

Results:

A total of 312 participants reported their plans for KT tool use. Parents who found the KT tool relevant were more likely to plan to use it at their child's upcoming vaccination. A total of 128 parents (93% mothers) completed both surveys. Nearly all parents who planned to use the information did so during their child's subsequent vaccination (90%). When the KT tool was relevant to their needs, parents were more likely to use the information during their child's vaccination. Parents who felt confident using the tool were significantly more likely to report plans for future tool use.

Discussion:

This study demonstrates the effectiveness of a KT tool that was relevant to parents' needs and built confidence to increase parent-reported uptake of evidence-based strategies. Proper pain management could positively impact parents' uptake of vaccinations for children.

Evaluation of the effect of selecting gluteal injection site on the pain injection based on anthropometric indices and body shape pattern: A randomised controlled trial study

AIMS AND OBJECTIVES

This study was aimed at comparing the effect of injection site selection based on anthropometric indices and body shape pattern on pain injection.

BACKGROUND

Pain is one of the common complications of intramuscular injection. Selecting the right place for gluteal injection is one of the challenges of nursing which can increase the safety and success of the injection and thereby reduce the pain severity caused by it.

DESIGN

Open-label randomized controlled trial study.

METHODS

In this study, 162 eligible subjects referred to the emergency unit of Vasei Hospital of Sabzevar, Iran were randomly assigned to three groups of control, anthropometric indices and body shape pattern. Subjects in the control group received dorsogluteal injection (traditional way). In the anthropometric group, body mass index (BMI), waist circumference (WC) and anterior superior iliac spine to iliac tubercle (ASIS-IT), and in body shape pattern group, observed body shape indices (OBS), BMI and sex were used to select the gluteal injection site. Pain injection was assessed using the Visual Analogue Scale (VAS). The CONSORT checklist was used.

RESULTS

The mean age of the participant was 39.43 ± 13.16 and 43.21% (n = 70) were male. Based on multiple linear regression analysis, the mean pain injection was substantially lower in body shape pattern as compared to the control group (r² : .26; bxy = -0.41; 95% CI: -0.81, -0.01; p = .043). The mean pain injection was significantly greater in the left leg injection than right one (r² : .26; bxy = 0.44; 95% CI: 0.06, 0.81; p = .021).

CONCLUSIONS

Findings of this study suggest that the selection of a gluteal injection site based on body shape pattern in comparison with traditional dorsogluteal injection method has a significant effect on pain injection relief.

RELEVANCE TO CLINICAL PRACTICE

Nurses can choose the appropriate gluteal injection site based on the body shape pattern to reduce the pain of the intramuscular (IM) gluteal injections.

Understanding and Minimising Injection-Site Pain Following Subcutaneous Administration of Biologics: A Narrative Review

Injection-site pain (ISP) is a subjective side effect that is commonly reported with the subcutaneous administration of biological agents, yet it may only be a concern to some. Multiple factors related to the product formulation, such as pH, volume and excipients, and/or to the injection process have the potential to contribute to ISP, while patient-related factors, such as low body weight, gender and age, can make an individual more susceptible to experiencing ISP. While total elimination of ISP remains unlikely with any subcutaneously administered agent, it can be minimised by helping the patient to develop a confident and competent injection technique via robust and effective training. Careful management of patient expectations along with open discussion regarding the potential risk of ISP may serve to minimise treatment-related anxieties and, importantly, allow the patient to remain in control of his/her treatment. Other interventions to help minimise ISP include psychological interventions, allowing biologics to reach room temperature prior to injection, using the most suitable injection device for the individual patient and selecting an alternative drug formulation, when available. Productive patient–physician communication remains important in order to support and optimise treatment experience and adherence, while also providing the opportunity for patients to discuss any ISP-related issues.

Influencing Vaccinations: A Buzzy Approach to Ease the Discomfort of a Needle Stick-a Prospective, Randomized Controlled Trial

BACKGROUND

The rate of annual influenza immunization in both the general public and health care workers is less than desirable. Mechanisms to improve compliance with recommendations are needed; prevention of immunization site pain has been suggested as a viable route because fear of pain and needles has been cited as a barrier.

AIMS

This study aimed to evaluate the impact of thermomechanical stimulation (Buzzy) on postprocedure pain ratings during vaccination in adults.

DESIGN

This was a randomized controlled trial of Buzzy during immunization.

SETTINGS

Three hospitals and two community health centers which are part of a large, integrated health system.

PARTICIPANTS/SUBJECTS

Employees presenting to employer-sponsored annual influenza vaccination clinics.

METHODS

A 10-cm visual analog scale was used to rate preinjection anxiety and expectation of pain as well as postprocedure pain scores; participants also rated their satisfaction with the vaccine injection on a 10-point Likert scale.

RESULTS

In total, 497 employee volunteers were recruited to participate. Preprocedure anxiety was similar between the experimental and control groups (1.53 vs. 1.48, p = .82), whereas self-reported postprocedure pain scores were significantly lower in the group that received the Buzzy during injection (0.87 vs. 1.12, p = .035). Mean satisfaction scores did not vary between the intervention and control groups (9.11 vs. 9.09, p = .87); however, more participants rated their experience as better than previous vaccination experiences in the Buzzy group than control (62.0% vs. 23.9%, p < .0001).

CONCLUSIONS

These results suggest that Buzzy reduced pain experienced by adults undergoing annual influenza vaccination and may improve overall experience. Buzzy can be used in adult patients to reduce pain during immunization and is especially effective in those with high levels of anxiety.

Needle size for vaccination procedures in children and adolescents

BACKGROUND

This is an update of a Cochrane Review first published in 2015. The conclusions have not changed.Hypodermic needles of different sizes (gauges and lengths) can be used for vaccination procedures. The gauge (G) refers to the outside diameter of the needle tubing. The higher the gauge number, the smaller the diameter of the needle (e.g. a 23 G needle is 0.6 mm in diameter, whereas a 25 G needle is 0.5 mm in diameter). Many vaccines are recommended for injection into muscle (intramuscularly), although some are delivered subcutaneously (under the skin) and intradermally (into skin). Choosing an appropriate length and gauge of a needle may be important to ensure that a vaccine is delivered to the appropriate site and produces the maximum immune response while causing the least possible harm. Guidelines conflict regarding the sizes of needles that should be used for vaccinating children and adolescents.

OBJECTIVES

To assess the effects of using needles of different sizes for administering vaccines to children and adolescents on vaccine immunogenicity (the ability of the vaccine to elicit an immune response), procedural pain, and other reactogenicity events (adverse events following vaccine administration).

SEARCH METHODS

We updated our searches of CENTRAL, MEDLINE, Embase, and CINAHL to October 2017. We also searched proceedings of vaccine conferences and two trials registers.

SELECTION CRITERIA

Randomised controlled trials evaluating the effects of using hypodermic needles of any gauge or length to administer any type of vaccine to people aged from birth to 24 years.

DATA COLLECTION AND ANALYSIS

Three review authors independently extracted trial data and assessed the risk of bias. We contacted trial authors for additional information. We rated the quality of evidence using the GRADE system.

MAIN RESULTS

We included five trials involving 1350 participants in the original review. The updated review identified no new trials. The evidence from two small trials (one trial including infants and one including adolescents) was insufficient to allow any definitive statements to be made about the effects of the needles evaluated in the trials on vaccine immunogenicity and reactogenicity.The remaining three trials (1135 participants) contributed data to comparisons between 25 G 25 mm, 23 G 25 mm, and 25 G 16 mm needles. These trials included infants predominantly aged from two to six months undergoing intramuscular vaccination in the anterolateral thigh using the World Health Organization (WHO) injection technique (skin stretched flat, needle inserted at a 90° angle and up to the needle hub in healthy infants). The vaccines administered were combination vaccines containing diphtheria, tetanus, and whole-cell pertussis antigens (DTwP). In some trials, the vaccines also contained Haemophilus influenzae type b (DTwP-Hib) and hepatitis B (DTwP-Hib-Hep B) antigen components.Primary outcomesIncidence of vaccine-preventable diseases: No trials reported this outcome.Procedural pain and crying: Using a wider gauge 23 G 25 mm needle may slightly reduce procedural pain (low-quality evidence) and probably leads to a slight reduction in the duration of crying time immediately after vaccination (moderate-quality evidence) compared with a narrower gauge 25 G 25 mm needle (one trial, 320 participants). The effects are probably not large enough to be clinically relevant.Secondary outcomesImmune response: There is probably little or no difference in immune response, defined in terms of the proportion of seroprotected infants, between use of 25 G 25 mm, 23 G 25 mm, or 25 G 16 mm needles to administer a series of three doses of a DTwP-Hib vaccine at ages two, three, and four months (moderate-quality evidence, one trial, numbers of participants in analyses range from 309 to 402. The immune response to the pertussis antigen was not measured).Severe and non-severe local reactions: 25 mm needles (either 25 G or 23 G) probably lead to fewer severe and non-severe local reactions after DTwP-Hib vaccination compared with 25 G 16 mm needles (moderate-quality evidence, one trial, 447 to 458 participants in analyses). We estimate that one fewer infant will experience a severe local reaction (extensive redness and swelling) after the first vaccine dose for every 25 infants vaccinated with the longer rather than the shorter needle (number needed to treat for an additional beneficial outcome (NNTB) with a 25 G 25 mm needle: 25 (95% confidence interval (CI) 15 to 100); NNTB with a 23 G 25 mm needle: 25 (95% CI 17 to 100)). We estimate that one fewer infant will experience a non-severe local reaction (any redness, swelling, tenderness, or hardness (composite outcome)) at 24 hours after the first vaccine dose for every 5 or 6 infants vaccinated with a 25 mm rather than a 16 mm needle (NNTB with a 25 G 25 mm needle: 5 (95% CI 4 to 10); NNTB with a 23 G 25 mm needle: 6 (95% CI 4 to 13)). The results are similar after the second and third vaccine doses.Using a narrow gauge 25 G 25 mm needle may produce a small reduction in the incidence of local reactions after each dose of a DTwP vaccine compared with a wider gauge 23 G 25 mm needle, but the effect estimates are imprecise (low-quality evidence, two trials, 100 to 459 participants in analyses).Systemic reactions: The comparative effects of 23 G 25 mm, 25 G 25 mm, and 25 G 16 mm needles on the incidence of postvaccination fever and other systemic events such as drowsiness, loss of appetite, and vomiting are uncertain due to the very low quality of the evidence.

AUTHORS' CONCLUSIONS

Using 25 mm needles (either 23 G or 25 G) for intramuscular vaccination procedures in the anterolateral thigh of infants using the WHO injection technique probably reduces the occurrence of local reactions while achieving a comparable immune response to 25 G 16 mm needles. These findings are applicable to healthy infants aged two to six months receiving combination DTwP vaccines with a reactogenic whole-cell pertussis antigen component. These vaccines are predominantly used in low- and middle-income countries. The applicability of the findings to vaccines with acellular pertussis components and other vaccines with different reactogenicity profiles is uncertain.

Engineering Microneedle Patches for Vaccination and Drug Delivery to Skin

Microneedle patches (MNPs) contain arrays of solid needles measuring hundreds of microns in length that deliver drugs and vaccines into skin in a painless, easy-to-use manner. Optimal MNP design balances multiple interdependent parameters that determine mechanical strength, skin-insertion reliability, drug delivery efficiency, painlessness, manufacturability, and other features of MNPs that affect their performance. MNPs can be made by adapting various microfabrication technologies for delivery of small-molecule drugs, biologics, and vaccines targeted to the skin, which can have pharmacokinetic and immunologic advantages. A small number of human clinical trials, as well as a large and growing market for MNP products for cosmetics, indicate that MNPs can be used safely, efficaciously, and with strong patient acceptance. More advanced clinical trials and commercial-scale manufacturing will facilitate development of MNPs to realize their potential to dramatically increase patient access to otherwise-injectable drugs and to improve drug performance via skin delivery.

Simple Psychological Interventions for Reducing Pain From Common Needle Procedures in Adults: Systematic Review of Randomized and Quasi-Randomized Controlled Trials

BACKGROUND

This systematic review evaluated the effectiveness of simple psychological interventions for managing pain and fear in adults undergoing vaccination or related common needle procedures (ie, venipuncture/venous cannulation).

DESIGN/METHODS

Databases were searched to identify relevant randomized and quasi-randomized controlled trials. Self-reported pain and fear were prioritized as critically important outcomes. Data were combined using standardized mean difference (SMD) or relative risk (RR) with 95% confidence intervals (CI).

RESULTS

No studies involving vaccination met inclusion criteria; evidence was drawn from 8 studies of other common needle procedures (eg, venous cannulation, venipuncture) in adults. Two trials evaluating the impact of neutral signaling of the impending procedure (eg, "ready?") as compared with signaling of impending pain (eg, "sharp scratch") demonstrated lower pain when signaled about the procedure (n=199): SMD=-0.97 (95% CI, -1.26, -0.68), after removal of 1 trial where self-reported pain was significantly lower than the other 2 included trials. Two trials evaluated music distraction (n=156) and demonstrated no difference in pain: SMD=0.10 (95% CI, -0.48, 0.27), or fear: SMD=-0.25 (95% CI, -0.61, 0.10). Two trials evaluated visual distraction and demonstrated no difference in pain (n=177): SMD=-0.57 (95% CI, -1.82, 0.68), or fear (n=81): SMD=-0.05 (95% CI, -0.50, 0.40). Two trials evaluating breathing interventions found less pain in intervention groups (n=138): SMD=-0.82 (95% CI, -1.21, -0.43). The quality of evidence across all trials was very low.

CONCLUSIONS

There are no published studies of simple psychological interventions for vaccination pain in adults. There is some evidence of a benefit from other needle procedures for breathing strategies and neutral signaling of the start of the procedure. There is no evidence for use of music or visual distraction.

New perineal injection technique for pudendal nerve infiltration in diagnostic and therapeutic procedures

PURPOSE

Pudendal nerve injection is used as a diagnostic procedure in the vulvar region and for therapeutic purposes, such as in vulvodynia. Here, we provide a new, easy-to-perform perineal injection technique.

PATIENTS AND METHODS

We analyzed 105 perineal injections into the pudendal nerve with a local anesthetic (LA), procaine in 20 patients. A 0.4 × 40 mm needle was handled using a stop-and-go technique while monitoring the patient's discomfort. The needle was placed 1-2 cm laterally to the dorsal introitus. After aspiration, a small amount of LA was applied. After subcutaneous anesthesia, the needle was further advanced step-by-step. Thus, 5 ml could be applied with little discomfort to the patient. Anesthesia in the pudendal target region was the primary endpoint of our analysis.

RESULTS

In 93 of 105 injections (88.6 %), complete perineal anesthesia was achieved with a single injection. 12 injections were repeated. These injections were excluded from the analysis. Severity of injection pain, on visual analog scale (VAS) from 0 to 100, was 26.8 (95 % CI 7.2-46.4). Age (β = 0.33, p < 0.01) and the number of previous injections (β = 0.35, p < 0.01) inversely correlated with injection pain. Injection pain and anesthesia were not affected by BMI, the number and the side of previous injections, or order of injection. A reversible vasovagal reaction was common, but no serious adverse effects occurred.

CONCLUSION

Perineal pudendal injection is an effective and safe technique for anesthesia in diagnostic (vulva biopsy) and therapeutic indications (pudendal neuralgia), and regional anesthesia in perinatal settings.

Effect of vaccine administration modality on immunogenicity and efficacy

The many factors impacting the efficacy of a vaccine can be broadly divided into three categories: features of the vaccine itself, including immunogen design, vaccine type, formulation, adjuvant and dosing; individual variations among vaccine recipients and vaccine administration-related parameters. While much literature exists related to vaccines, and recently systems biology has started to dissect the impact of individual subject variation on vaccine efficacy, few studies have focused on the role of vaccine administration-related parameters on vaccine efficacy. Parenteral and mucosal vaccinations are traditional approaches for licensed vaccines; novel vaccine delivery approaches, including needless injection and adjuvant formulations, are being developed to further improve vaccine safety and efficacy. This review provides a brief summary of vaccine administration-related factors, including vaccination approach, delivery route and method of administration, to gain a better understanding of their potential impact on the safety and immunogenicity of candidate vaccines.

Needle size for vaccination procedures in children and adolescents

BACKGROUND

Hypodermic needles of different sizes (gauges and lengths) can be used for vaccination procedures. The gauge (G) refers to the outside diameter of the needle tubing. The higher the gauge number, the smaller diameter of the needle (eg a 25 G needle is 0.5 mm in diameter and is narrower than a 23 G needle (0.6 mm)). Many vaccines are recommended for injection into muscle (intramuscularly), although some are delivered subcutaneously (under the skin) and intradermally (into skin). Choosing an appropriate length and gauge of a needle may be important to ensure that a vaccine is delivered to the appropriate site and produces the maximum immune response while causing the least possible harm. There are some conflicting guidelines regarding the lengths and gauges of needles that should be used for vaccination procedures in children and adolescents.

OBJECTIVES

To assess the effects of using needles of different lengths and gauges for administering vaccines to children and adolescents on vaccine immunogenicity (the ability of the vaccine to elicit an immune response), procedural pain, and other reactogenicity events (adverse events following vaccine administration).

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (The Cochrane Library 2014, Issue 10), MEDLINE and MEDLINE in Progress via Ovid (1947 to November 2014), EMBASE via Ovid (1974 to November 2014), and CINAHL via EBSCOhost (1982 to November 2014). We also searched reference lists of articles and textbooks, the proceedings of vaccine conferences, and three clinical trial registers.

SELECTION CRITERIA

Randomised controlled trials evaluating the effects of using hypodermic needles of any gauge or length to administer any type of vaccine to people aged from birth to 24 years.

DATA COLLECTION AND ANALYSIS

Three review authors independently extracted trial data and assessed the risk of bias. We contacted trial authors for additional information. We rated the quality of evidence using the GRADE system.

MAIN RESULTS

We included five trials involving 1350 participants. Data for the primary review outcomes were either absent (for the incidence of vaccine-preventable diseases) or limited (for procedural pain and crying). The available evidence was compromised by the use of surrogate immunogenicity outcomes, incomplete blinding of outcome assessors, and imprecision for some outcomes. The evidence from two small trials was insufficient to allow any confident statements to be made about the effects of the needles evaluated in the trials on vaccine immunogenicity and reactogenicity.The remaining three trials (1135 participants) contributed data to comparisons between 25 G 25 mm, 23 G 25 mm, and 25 G 16 mm needles. These trials involved infants predominantly aged two to six months undergoing intramuscular vaccination in the anterolateral thigh using the World Health Organization (WHO) injection technique (skin stretched flat, needle inserted at a 90° angle and up to the needle hub in healthy infants). The vaccines administered were combination vaccines containing diphtheria, tetanus, and whole-cell pertussis antigens (DTwP). In some trials, the vaccines also contained Haemophilus influenzae type b (DTwP-Hib) and hepatitis B (DTwP-Hib-HepB) antigen components.We found moderate quality evidence from one trial that there is probably little or no difference in immune response, defined in terms of the proportion of seroprotected infants, between using 25 G 25 mm, 23 G 25 mm, or 25 G 16 mm needles to administer a series of three doses of a DTwP-Hib vaccine at ages two, three, and four months (numbers of participants in analyses range from 309 to 402. Immune response to pertussis antigen not measured).25 mm needles (either 23 G or 25 G) probably lead to fewer severe local reactions (extensive redness and swelling) and fewer non-severe local reactions (any redness, swelling, tenderness or hardness (composite outcome)) after DTwP-Hib vaccination compared with 25 G 16 mm needles. We estimate that one fewer infant will experience a severe local reaction after the first vaccine dose for every 25 infants vaccinated with the longer rather than the shorter needle (number needed to treat (NNT) 25 (95% confidence interval (CI) 15 to 100)). We estimate that one fewer infant will experience a non-severe local reaction at 24 hours after the first, second, and third vaccine doses for every five to eight infants vaccinated with the longer rather than the shorter needle (NNTs range from 5 (95% CI 4 to 10) to 8 (95% CI 5 to 34)) (moderate quality evidence, one trial for first and second doses, two trials for third dose, numbers of participants in analyses range from 413 to 528).Using a wider gauge needle (23 G 25 mm) may slightly reduce procedural pain (low quality evidence) and probably leads to a slight reduction in the duration of crying time immediately after vaccination (moderate quality evidence) compared with a narrower gauge (25 G 25 mm) needle (one trial, 320 participants). The effects are probably not large enough to be of any clinical relevance. The 25 G 25 mm needle may produce a small reduction in the incidence of local reactions after each dose of a DTwP vaccine compared with the 23 G 25 mm needle, but the effect estimates are imprecise (low quality evidence, two trials, numbers of participants in analyses range from 100 to 459).The comparative effects of 23 G 25 mm, 25 G 25 mm, and 25 G 16 mm needles on the incidence of post-vaccination fever, persistent inconsolable crying, and other systemic events such as drowsiness, loss of appetite, and vomiting are uncertain due to the very low quality of the evidence.

AUTHORS' CONCLUSIONS

Using 25 mm needles (either 23 G or 25 G) for intramuscular vaccination procedures in the anterolateral thigh of infants using the WHO injection technique probably reduces the occurrence of local reactions while achieving a comparable immune response to 25 G 16 mm needles. These findings are applicable to healthy infants aged two to six months receiving combination DTwP vaccines with a reactogenic whole-cell pertussis antigen component. These vaccines are predominantly used in developing countries. The applicability of the findings to vaccines with acellular pertussis components and other vaccines with different reactogenicity profiles is uncertain.

Enabling skin vaccination using new delivery technologies

The skin is known to be a highly immunogenic site for vaccination, but few vaccines in clinical use target skin largely because conventional intradermal injection is difficult and unreliable to perform. Now, a number of new or newly adapted delivery technologies have been shown to administer vaccine to the skin either by non-invasive or minimally invasive methods. Non-invasive methods include high-velocity powder and liquid jet injection, as well as diffusion-based patches in combination with skin abrasion, thermal ablation, ultrasound, electroporation, and chemical enhancers. Minimally invasive methods are generally based on small needles, including solid microneedle patches, hollow microneedle injections, and tattoo guns. The introduction of these advanced delivery technologies can make the skin a site for simple, reliable vaccination that increases vaccine immunogenicity and offers logistical advantages to improve the speed and coverage of vaccination.

The effect of brief functional relaxation on college students' needle anxiety during injected vaccinations

OBJECTIVE

This study examined the effect of brief functional relaxation (FR) training on needle anxiety (NA) during vaccinations.

PARTICIPANTS

From October 2010 through May 2012, 48 undergraduates were recruited through the psychology research participant pool.

METHODS

Students (N = 48) were randomly assigned to a 15-minute brief FR session delivered via MP3 player or a standard care condition (15 minutes of sitting quietly) prior to receiving injections at the immunization clinic. Measures were completed before (T1) and after (T2) the assigned condition, assessing expected NA, state anxiety, blood pressure, and heart rate; and after the injection (T3), self-reported NA during the injection.

RESULTS

Unexpectedly, the groups did not differ at T2. However, during the injection, brief FR participants indicated lower self-reported NA (T3) than standard care.

CONCLUSIONS

Brief FR is a simple, inexpensive technique that may reduce NA in college health settings and help decrease delays in treatment seeking.

Evaluation of monophosphoryl lipid A as adjuvant for pulmonary delivered influenza vaccine

Prophylaxis against influenza could be improved by the development of a stable, easy to deliver, potent mucosal vaccine. In this study, we spray-freeze-dried (SFD) whole inactivated virus influenza vaccine (WIV) alone or supplemented with monophosphoryl lipid A (MPLA) using inulin as a lyoprotectant. Physical characterization revealed that the SFD powder consisted of highly porous particles with a size distribution suitable for pulmonary administration. The receptor-binding properties of WIV and the immunostimulatory properties of MPLA were preserved after spray-freeze-drying as indicated by unchanged hemagglutination titers and a retained ability of the vaccine to activate NFkB after incubation with a reporter cell line, respectively. Pulmonary vaccination of mice with MPLA-adjuvanted liquid or powder WIV resulted in induction of higher mucosal and systemic antibody concentrations than vaccination with non-adjuvanted formulations. When exposed to influenza virus, mice immunized with MPLA-adjuvanted pulmonary vaccine showed similar protection in terms of reduction in lung virus titers and prevention of weight loss as mice immunized intramuscularly with subunit vaccine. Characterization of the antibody response revealed a balanced IgG2a-to-IgG1 profile along with induction of both memory IgA- and IgG-producing B cells in mice immunized with MPLA-adjuvanted vaccine. These studies suggest that the mucosal and systemic immune responses to pulmonary delivered influenza vaccines can be significantly enhanced by using MPLA as adjuvant. MPLA-adjuvanted SFD vaccine was particularly effective implying that delivery of adjuvanted vaccine powder to the lungs can be an attractive way of immunization against influenza.

Predictors of pain during and the day after corticosteroid injection for idiopathic trigger finger

PURPOSE

Some patients report a transient increase in pain the day after a corticosteroid injection. We investigated factors associated with greater pain during and the day after a corticosteroid injection for idiopathic trigger finger.

METHODS

A total of 100 patients with trigger finger completed questionnaires measuring heightened illness concern, catastrophic thinking, depression, perceived health, expected pain, pain with injection, and pain the day after injection. We performed bivariate analysis to determine variables associated with pain with injection, next-day pain, and next-day pain greater than 4 points on an 11-point ordinal scale. We entered variables with a significant correlation into multivariable linear regression models.

RESULTS

The average pain with injection and the day after injection were 4.3 (SD 2.8) and 1.8 (SD 2.0), respectively. Expected pain, heightened illness concern, catastrophic thinking, depression, physician, and gender correlated with pain with injection. A multivariable regression model conducted in backward stepwise fashion demonstrated that physician, depression, expected pain, and female gender explained 28% of the variance in pain with injection. Pain with injection was the only significant predictor of next-day pain and pain greater than 4 points the day after injection.

CONCLUSIONS

Our data suggest that psychosocial factors are the strongest correlates of pain with corticosteroid injection, but a large portion of the variability remains unexplained. Future research will investigate cognitive/behavioral methods for decreasing pain with injection.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic I.