Index
- Basic Concept
- Terminology
- Types of Injection Devices
- Injection and Lancing Techniques
- Physical Adaptations
- Buzzy Device
- Multitasking Diversion and Language Processing
- This is different from distraction.
- Difference betweeen diversion and distraction
- Neurological Basis Inherent in Multitasking Diversion
- Footnotes and References
Basic Concept
Needles are of course the most common invasive medical treatment. Getting an injection (IM or SC), lancing (finger prick) and venipuncture are not going to be the most painful thing that one will experience that week. Nevertheless, it is not uncommon for people to consider needles to be fairly traumatic. The idea is to come up with strategies to turn this into a non-event, or (in some cases) an interesting or even pleasant(!) activity.
As an incidental matter of curiosity, the sensation for intramuscular injections is primarily at the dermal layers (specifically in the dermis). While there are nerve endings in the muscle, as evidenced by muscle soreness after some immunizations, the muscles are likely less involved in the what one feels with an injection.
There are 3 approaches to reducing needle pain and needle phobia:
- Technique
- injection and lancing techniques
- Physical
- various treatments ranging from local or topical anesthetic to physical stimulation devices
- Use of multitasking techniques to divert or "distract" the mental process
- I made this "skip to the end of the page", but really, multitasking diversion should be part of every needle technique, regardless of level of needle apprehension.
Neurological Basis Inherent in Multitasking Diversion- Concepts and avenues for further research into physical techniques and diversion techniques
Terminology - There are various types of injections, including:
- intramuscular (IM)
- - the common inoculation technique, involving injection into muscular tissue. Most of the sensation is at the dermal (skin) layer, although, if any, following the injection, would be deeper.
- subcutaneous (sub-Q or SC)
- - injection into the fatty layer below the skin. This is sometimes used for immunization, and is commonly used for insulin and most routinely injected pharmaceuticals using pen injectors and single-use autoinjector pens (e.g., injectable GLP-1 agonists). SC is considered to more slowly dissipate than IM, and therefore, autoinjectors intended for rapid response (e.g., epi-pens) are designed to effect an IM injection instead of SC.
- venipuncture (IV, VP, phlebotomy or infusion)
- - a specialised technique administered by trained professionals or phlebotomists (who are also trained professionals). Recreational "hard drug" users, typically addicts, also inject directly to the vein.
- lancing (finger prick)
- - uses a lancing device for blood sampling at a sampling site using a test strip. The test strip is typically inserted into a small reading device before touching a blood drop at the sampling site.
- continuous monitors or continuous meters (CGM)
- - some continuous monitors use a small needle probe attached to a patch on the skin, often automatically taking periodic readings for continuous monitoring. These are reportedly painless due to the size of the needle probe. These are most commonly used for blood glucose measurements (CGM). There are other types of continuous monitors, such as alcohol monitors, that do not use probe needles, but rather conduct measurements at the surface of the skin.
- gauge (diameter)
- - gauge (G) is the diameter as measured by the by the Birmingham gauge scale. The gauge number is the inverse of the diameter, meaning that a 27 G needle (0.413 mm dia.) is thinner than a 23 G (0.64 mm dia.) needle, etc. A 32 G (0.23 mm dia.) pen needle is of course thinner than a 27 G (0.413 mm dia.) needle used with syringes. (This "guage" measurement scale is used internationally, although SI units are sometimes also given.)
Injection Devices and Techniques
Types of Injection Devices
Common injection devices include:
- Conventional syringes
- These are the familiar syringes, for example, used for most immunization jabs ("shots" in the US because the term "shots" reminds people of a familiar every-day activity.)
Syringes are either filled from a vial or are pre-filled with the medication. The injection is applied at a 90° angle for IM and a 45° (or 90°) angle for SQ. For SQ self-injection, it is common to lightly pinch the skin while injecting.
Syringe needles generally range between 14 and 27 gauge (1.83 mm to 0.42 mm), with the higher number (27 gauge or 0.42 mm) being the thinnest. Most vaccines are administered with 23 through 27 gauge needles. Sizes as small as 30 gauge are available, but are less common.
- Pen Needle Injectors (Pen Needles)
- These are multi-dose injectors, with separate heads (also called "pen needles"). Typically the cartridge part, called the "pen" or "pen injector", is supplied with multiple doses of the medication. [2]
Pen needle sizes vary. A common size for the pen needle is 32 gauge, 4 mm, which (especially with the use of multitasking techniques) are mostly painless. [3]
CautionPen injectors should not be shared, even with fresh needles, because of the potential for backflow of body fluids into the medication supply. The pen injector cartridge is not under pressure except during dosing, so backflow is apparently a significant possibility.
Do not leave an open needle attached to a pen injector. Leaving a pen needle attached to a pen injector can lead to unintentional air entering the pen injector. Removing the used pen needle before stowing the pen injector allows the pen injector to seal shut and prevents air bubbles from accumulating within the pen injector. [4]
Pre-filled injectors are typically multi-dose, so be sure to select the correct dose before injecting.
- Autoinjectors
- Single-use syringes, typically activated by pressing a button or by needle insertion. These are use SQ and IM.
Activation by needle insertion is common with emergency IM medications, such as EpiPen (epinephrine autoinjector) devices. Autoinjectors typically retain the needle retracted until activation, at which time the needle extends, followed by injection of the medication, followed by the needle retracting. The autoinjector is removed upon indication of retraction or after a brief time.
Needle size varies by application. Typical sizes for SQ autoinjectors are 26 to 31 gauge.[1] EpiPens are typically 22 gauge (Auvi-Q uses 23 G), presumably to facilitate injection through clothing when used in an emergency.
- Venipuncture needles
- These include cannula needles and butterfly needles, multiple drawing needles, and hypodermic syringe needles, used by phlebotomists. ("Multiple drawing needles" are used on a single patient for multiple test specimens.)
Injection and Lancing Techniques
There are "best practices" for administering injections. Most are used by trained professionals, such as:
- Position the patient so the muscles are relaxed
- With a firm or "deliberate" thrust, put the needle into the muscle straight up and down,
- at a 90° angle for IM and a 45° (or 90°) angle for SQ using conventional needles, and 45° for venipuncture. Pen injectors (multiple use pen injectors) (multi-use injectors with replaceable 'pen needle' tips) using pen needles up to 6 mm, and most single-use autoinjectors are generally applied at a 90° angle.
- Insert and remove the needle smoothly and quickly. Especially for IM, "firm or deliberate" would not be slow, and probably not excessively rapid.
- It is also common to pinch a fold of skin for SQ injections using a conventional needle. In most cases, this is not beneficial with pen injectors or pen needles. Since injection depth of pen injectors and pen needles is limited by design, it is generally not necessary to pinch the skin.
- It had been common for some people who performed self-injection with conventional syringe needles to lightly lightly probe the site to find a location with reduced nerve sensitivity. This worked because most of the pain sensation occurs at the skin layer, even for IM injections.
There are different criteria used for particular pharmaceuticals. Especially on-line, ascertain if the discussion or commentary is directed to the particular type of pharmaceutical being used to be sure that the information is relevant to your situation. Suitable information can be obtained from the treating physician and possibly from other people undergoing the same treatment.
Notably, testosterone is more viscous than some other commonly prescribed injectable medications, and is easier to administer with larger needle diameters (lower needle gauge numbers) than, for example, insulin injections. Likewise, on-line descriptions of testosterone treatment are likely to include information that is not relevant to most other injectable pharmaceutical treatments.
Lancing technique is somewhat different. Since the purpose is to draw blood for sampling, the factors such as needle size must be balanced. Criteria selected are:
Due to the different variables, there is no single "best approach" to lancing.
- Site selection for finger prick
- (Most patients know this but ...) A finger prick should be made away from the base of the fingertip, toward the sides. In addition to this providing two different sites per finger, this moves the lance away from the center, where most of the nerve endings are located. (If you notice a nurse prepping the center of the finger, ask the nurse to lance the finger somewhat off-center.)
- The particular brand of lancing device used
- (e.g., "universal" square-base lancet vs. lancets designed to fit a specific lancing device)
- Lance needle size
- 28 gauge is most common, but sizes down to 33 are now readily available.
- Depth of penetration, as controlled by the lancing device
- "alternate site" selection
- "Alternate sites" are at locations with fewer pain nerve endings than the fingertips, resulting in painless sampling. The problem is that "alternate site" samples are not as temporally accurate as fingertip (side of fingertip) sampling.
Finger lancing provides more current readings, but in many cases the timing is not critical. Proper "alternate site" selection is given in the instructions for the reading device or meter, but this seems to be more related to government certification for the reading device. In any case, follow instructions for "alternate site" selection, even if you are using the instructions for a different reading device than the one you are using. Do not use "alternate site" selection if you are taking time-sensitive readings, such as checking for hypoglycemia, because the "alternate site" sample will not give you the essential current values.
Physical Adaptations
Physical technique and treatments to reduce pain include:
In many cases, one will find that the use of these physical aids is no longer necessary, or at least no longer necessary for ordinary injections.
- probing (for self-injection)
- This was originally done for self-injection, using standard needles. By touching the needle to the skin, one could identify a location with reduced nerve sensitivity. This worked because most of the pain sensation occurs at the skin layer, even for IM injections.
For pen needles and autoinjectors, probing with the needle itself is difficult or impossible, but it is possible to touch the skin with another object or the edge of the base of an autoinjector. As a practical matter, probing is not really necessary using the finer needles used in autoinjectors, and especially pen needles. In the case of multi-use pen injectors with removable pen needles, the needle (e.g., 32 gauge 4 mm pen needle) is likely be sufficiently fine that one doesn't consider insertion painful for most drugs, notably insulin.
Probing is still somewhat possible with single-use auto-injector pens, although generally not worth the trouble. In the case of a single-use auto-injector, the edge of the base can be used to probe the skin. For typical fine gauge pen needles, probing with the needle should not be performed.
(Some drugs, notably testosterone, require a larger diameter needle, such as 30 or 28 gauge on pen injectors, and 25 to 22 gauge for standard needles, but the information on "T" is widely available elsewhere on the web.)
- Buzzy
- Buzzy is a small vibrator with a small cold compress pad.
The Buzzy device is placed over the injection or venipuncture site for about 20 seconds and removed prior to injection. It can be moved proximally while the venipuncture site is being prepped (with alcohol), but as a practical matter, just remove it because the tourniquet is wrapped at the same time. For ordinary injections, it's also easiest to just remove the Buzzy when the site is being prepped, although their website image shows a slightly anxious-looking child holding the device proximally from the injection. [5]
Buzzy is sold directly at Buzzyhelps / paincarelabs.com . The "Mini Personal" model is probably most convenient. They have "personal" and "healthcare" models, the difference being the "healthcare" model is resistant to disinfectant (for multiple patients). You will also need an insulated lunch bag and a flexible "blue ice" ice pack to keep the cold compress pads from thawing. I bring at least 3 pads in anticipation of clinic delays.
The buzzy is slightly awkward, but clinicians seem to welcome the device, as clinicians are quite used to anxious patients.
Buzzy also makes a Buzzy Pro device, intended for dialysis, infusion, and other long venipuncture procedures.
- knobby pads
- These look like a soap tray with flexible knobs. - Probably less effective than just talking during the jab.
A product called "TickleFLEX" fits injection pens, such as insulin injection pens. Generally, due to the small needle size of pen needles, most patients would consider this device to be superfluous, but it may be useful for paediatrics.
- TENS (Transcutaneous Electrical Nerve Stimulation)
- These are devices which use electrical currents to block pain. The currents stimulate the nerve endings with an intensity below motor contraction, and thereby reduce pain sensation. The effect is to interrupt pain signals in the body. The efficacy of TENS in reducing the sting reflex from needles is not clear, and TENS is not reported to be in common use to divert needle pain.
Of note, TENS is commonly used with dry needling (similar to acupuncture, but applying different medical theories), as Percutaneous Electrical Nerve Stimulation (PENS).
- TAC, Lidocaine, EMLA (Eutectic Mixture of Local Anesthetics) and similar topical anesthetics
- These need application about 20 minutes in advance, although it's likely that some spray-on dental versions (e.g., Nummit spray) are quicker acting.
- A rather large rubber mallet
- This is administered by a nurse or other medical professional to ka-klunk the patient in the head. The injection or venipuncture is administered or performed while the patient is somewhat unconscious. Some patients have reported headaches following this procedure.
Multitasking Diversion
This is the easiest technique, and I'm surprised this isn't implemented by most clinicians.
The catch - "It's all in your mind." (In other words, it's a neurological function.)
This is generally viewed as trying to distract the patient; however distraction will be necessarily limited. Instead, the purpose is to divert the patient's attention. In particular, the "diverting attention" is more neurological than psychological.
How it works
(This neurological analysis is primarily observational and not a peer reviewed analysis. There may be other explanations for this observation, but this form of using communication to establish multitasking seems to be very effective.)
The neurological pathway for processing language (listening and speaking both seem to work) is such that if one is processing language, one is less able to notice incidental pain.
People are basically not very good at mental "multitasking", at least at the neurological level, so if one engages in conversation, one is unable to focus on a needle sting (and in some cases won't feel a sting at all). It is only necessary to identify a mental or neurological function that diverts the conscious attention to the initial sensation of the needle.
This is a little different from distraction, in that the whole "talking" thing does not require distraction; only a slight amount of engagement or attempting to focus on the conversation sufficiently. Therefore, achieving actual distraction is not really necessary, as the speech and language processing itself is sufficient to provide the desired "multitasking diversion" function. It is also easier than trying to distract someone, in part because the patient is already a little bit nervous, so may find some forms of distraction annoying. On the other hand, speaking, but not involving a task, can be soothing or at least not add to the tension.
While a clinician talking will cause the patient to listen, this also works with the patient doing the talking.[6] The conversation topic doesn't really matter. I've given instructions to patients on what to do after an immunization, but repeated the same thing after the jab because I presumed the patient didn't even comprehend what I was saying in the middle of the procedure. When I'm getting a jab, I usually talk to the clinician about what the clinician is doing or simply the reason I need to talk during the jab.
When alone (self-injection), one can listen to radio or television talk programming (talk radio, news, interviews, most TV programs, etc.) Obviously one is also concentrating on performing the injection, but the idea is to intentionally multitask sticking oneself with whatever one is listening to.
... but not an attempt at distraction
Diversion techniques differ from distraction in that:
- Distraction is difficult to achieve.
- In most cases, one is in a clinical environment, expecting to get a jab. Trying to distract one from the imminent jab is just 'not gonna work'.
- Distraction, if successful, can provoke a startle response.
- ... which is conceptually similar to the "sting" response. Distraction may even increase anxiety of jabs in the future,
whereas, unlike distraction, diversion avoids the startle response.
- Distracting oneself for self-injection is pretty much impossible.
- If self-injecting, one is focused on executing the injection.
- Distraction involving significant interaction can increase tension during the jab.
- Think of engaging with a cashier clerk who is asking annoying questions while you are trying to monitor the transaction. (On the other hand, it may be advantageous to engage the patient with enjoyable banter. Humor can be useful.)
- Try to avoid asking questions that require thought (unless the thought is entirely pleasant).
- Diversion is effective even if the subject matter used for distraction is some aspect of the inoculation itself.
Neurological Basis Inherent in Multitasking Diversion
As indicated supra, This neurological analysis is not a peer reviewed analysis. As such, the described effects, especially relating to diverting attention from pain stimuli, are observational. This is particularly the case with multitasking established by language processing.
The following is a general explanation of the basis for diverting attention. This is intended for lay understanding, but ...
"There has been substantial progress over the last several years in understanding aspects of the functional neuroanatomy of processing language. It is argued that recognizing speech sounds is carried out in the superior temporal lobe bilaterally, that the superior temporal sulcus bilaterally is involved in phonological-level aspects of this process, that the frontal/motor system is not central to speech recognition although it may modulate auditory perception of speech, that conceptual access mechanisms are likely located in the lateral posterior temporal lobe (middle and inferior temporal gyri), that speech production involves sensory-related systems in the posterior superior temporal lobe in the left hemisphere, that the interface between perceptual and motor systems is supported by a sensory-motor circuit for vocal tract actions (not dedicated to speech) that is very similar to sensory-motor circuits found in primate parietal lobe. It is further argued that verbal short-term memory can be understand as an emergent property of this sensory-motor circuit. These observations are understood within the context of a dual stream model of speech processing in which one pathway supports speech comprehension and the other supports sensory-motor integration. Additional possible factors include the functional organization of the planum temporale for spatial hearing and speech-related sensory-motor processes, the anatomical and functional basis of a form of acquired language disorder, conduction aphasia, the neural basis of vocabulary development, and sentence-level/grammatical processing." [paraphrased from source][7]
One possible explanation of why language processing can be effective would involve neural processing. It has been argued that the phonological-level aspects of speech and language processing is carried out in the superior temporal lobe bilaterally. This is separate from the frontal/motor system, which is linked to the phonological-level aspects of this process. Speech processing likely located in the lateral posterior temporal lobe, and involves an interface between perceptual and motor systems, but is perhaps a property of this sensory-motor circuit. As such, language processing may have the effect of diverting neurological resources from the recognition of a needle prick.
This sort of diversion would be largely ineffective for pain extending over a significant period of time, but in the case of a needle, the time involved in initial insertion is likely to be analogous to a startle response of less than 1 second in duration. This differs from distraction, in that, using language processing during the the procedure interferes with neural communication of the initial prick, so that the sting response is attenuated; whereas distraction attempts to make the patient less unaware of needle procedure.
(There may be other explanations for this observation, but from an observational standpoint, this form of using communication and language processing to establish multitasking seems to be very effective.)
FOOTNOTES AND REFERENCES:
- [1]^ One report from "Diabetes in Control" (.pdf) from 11-2014 gives the size of Lilly's autoinjector for their Trulicity GLP-1 agonist as 29 gauge, 5 mm (for the autoinjector version), with a 2025 report describing 31 gauge (for their tirzepatide (Mounjaro) autoinjectors, but should be the same for all GLP-1). A different version of Lilly's autoinjector, used for antimigraine drug Emgality (galcanezumab-gnlm), was reported to use a 27 gauge, 12.7 mm needle, also intended for SQ injection. The dosage is 120 mg, which could be the reason for the longer needle.
- [2]^ Pen needle descriptions and instructions:
- Pen Needles & Syringes from lay advocate Christel's Diabetes Strong Youtube channel - describes pen needles and size selection
"Quick Guide for FlexPen" from Novo Nordisk
"Proper injection technique" from BD/emecta
another BD video - this one in a deeper voice
HTL-Strefa pen needle instructions (.pdf)
- [3]^ Pharmaceutical manufacturers and others are recommending shorter lengths for pen needles (4 mm, 32 G for insulin, as of 2024). e.g.:
- New Insulin Delivery Recommendations, Mayo Clin Proc. 2016 Sep;91(9):1231-55. doi: 10.1016/j.mayocp.2016.06.010.
- BD 4 mm pen needle worksheet (.pdf) Note: BD has apparently spun off some or all of its insulin delivery manufacturing (i.e., most pen needles) to Embecta Corp.
- Novo Nordisk needle portfolio ("4 mm needles are associated with less risk of intramuscular injections compared to 6 mm needles")
- Gibney, et. al., Skin and subcutaneous adipose layer thickness in adults with diabetes at sites used for insulin injections: implications for needle length recommendations, Current Medical Research and Opinion, 01 Jun 2010, 26(6):1519-1530 PMID: 20429833 - early report advocating 4-5 mm needles (.pdf link)
The first injector pen was introduced by Novo Nordisk in 1985, to administer insulin products, with further introductions in 1991-1999. The original production by Novo (1985) and BD (1991) were 12.7 mm 29 G. BD introduced a 4 mm x 32 G pen needle in 2009 ("A long history and rich heritage in diabetes" chart in embecta 7-Mar-2022 initial investor presentation (.pdf) ). Current recommendations are for the 4 mm length, but thinner pen needles have been proposed, including a 3.5 mm, 34 G pen needle introduced by Italian firm HTL-Strefa, sold as droplet Micron and Insupen 34G 3.5mm. (As of this writing, there are few field reports on these 3.5mm 34G pen needles; the only independent report I saw being unfavourable.)
- BD 4 mm pen needle worksheet (.pdf) Note: BD has apparently spun off some or all of its insulin delivery manufacturing (i.e., most pen needles) to Embecta Corp.
- [4]^ There are reports of reuse of pen needles in needle injectors, for example to completely use up the medication in a first injector.
- While this practice is not universally recommended, if two pen injectors are used for one dose, a single fresh needle could be used for both injections making up the one dose, so as to avoid re-using a needle from a previous dose. (NIH PubMed abstract) Int J Nurs Stud. 2016 Aug:60:121-32. doi: 10.1016/j.ijnurstu.2016.04.010. Epub 2016 Apr 27 ("There is currently no clear scientific evidence to suggest for or against the reuse of needles for subcutaneous insulin injection. This practice is very common among people with diabetes; consequently, further research is necessary to establish its safety. ")
Leaving a needle in the pen injector leaves the pen injector subject to contamination. (As mentioned, the same pen injector must not be used for more than one patient.)
- [5]^ Buzzy literature review (2024 update) (.pdf)
- alternative link: Buzzy Literature Review (2022) (.pdf)
- A similar listing of references also appears as a chart on their "Science" page.
- TED Talk by Dr. Amy Baxter, inventor of Buzzy can be viewed here.
- alternative link: Buzzy Literature Review (2022) (.pdf)
- - Amy Baxter's talk includes a convincing explanation describing needle pain as as a motivation for the anti-vaxxer movement.
- [6]^ For non-speaking people (e.g., people with mutism, selective mutism (ref.) (ref.), etc.), some adaptations may be advantageous; e.g., listening to voice via earpods can be as effective as speaking in implementing language processing.
- [7]^ Hickok G. The functional neuroanatomy of language. Phys Life Rev. 2009 Sep;6(3):121-43. doi: 10.1016/j.plrev.2009.06.001. PMID: 20161054; PMCID: PMC2747108.
Additional References:
On skoozeme.com :
- Virginia's Model Pen Needle act
- Describes a "Model Act" provision in the Virginia Code that excludes pen needles from restrictions related to prohibition of distribution of hypodermic needles
Comments about this site: email mefirst posted 14-Oct-2024; rev 19-Apr-2025 This page copyright 2024, Stan Protigal
