By Adam Weaver, PT, DPT
The use of dry needling as a clinical treatment for physical therapists continues to grow. Regulations now allow dry needling to be performed by clinicians in over 35 states in the United States, and national APTA opinion supports the technique. As research supporting dry needling for various health professions continues to emerge, it is likely that the use of this treatment will continue to expand in the future.
After recent published case reports regarding significant adverse events with dry needling, it is appropriate to clarify the definition of adverse events, look at recent trends, and make recommendations for all clinicians to maintain the greatest adherence to safety.
What is an adverse event?
Adverse events are often classified based on severity, as described by Carnes et al. Mild events are defined as short-term and non-serious with no change in function. Moderate and major adverse events are defined as serious and often require further treatment from other medical professionals. Time frames for these events have not been specifically defined, but typically mild events last a few hours, whereas moderate and major events last days to weeks.
Since the rise in dry needling usage and support will likely continue in the physical therapy profession, it is important that clinicians, both novice and experienced, have a healthy respect for adverse events, as dry needling is considered an invasive technique. Adverse events can be defined as ‘any ill-effect, no matter how small, that is unintended and non-therapeutic.’ These events were reported by White et al. in a survey of over 32,000 consultations; the different types of events are shown below.
A recent review of the literature has not shown any studies reporting adverse events associated with dry needling beyond the level of case study. Until recently, most evidence reported by commercial educational models and academia stemmed primarily from prospective studies investigating adverse events following acupuncture. While these studies relate to acupuncture and are difficult to fully apply to dry needling, the similarity of the solid filament needle can provide useful safety information.
In the only published study involving dry needling and physical therapists, a prospective survey of physical therapists showed no significant adverse events occurred in over 7,600 treatments. Though the definition of an adverse event is quite broad, the goal of every clinician should be to avoid all adverse events of any kind. Minor events typically include patient responses that have minimal short-term physical effects, while severe events typically warrant further medical attention.
Interestingly, pneumothorax was not discussed in any of these surveys, and there is minimal literature to date beyond several case reports. Clinically, there is legitimate concern when treating around the lung field, specifically the rib cage and upper trapezius regions. Incidence of pneumothorax with monofilament needles has been reported in one study to be less than 1 in 100,000.
In comparison, with respect to larger needles (17 gauge) used for biopsies in and around the lung field, the incidence of pneumothorax is about 1 in 5. However, reports of spontaneous pneumothorax have an incidence of 7.4-18 cases per 100,000 population in males, and 1.2 to 6 cases per 100,000 population each year in females. Furthermore, recent case reports and anecdotal reporting may suggest that this number is actually higher. This area will continue to receive notable attention, as it should, although reports should be interpreted with appropriate consideration.
Are these events trending upwards?
While more adverse events are being reported in the literature, the number of clinicians regularly employing the use of this technique has also risen dramatically in the last five years. Since 2014, over 7,000 clinicians have been trained by KinetaCore, with many more trained by other educational companies. No studies have been published to date discussing the rise in adverse events. However, there is an increased focus and attention in research on the efficacy of dry needling, which has led to a higher number of published results pertaining to it.
Several recent case reports with data on adverse events were published in 2018. Kim et al. reported a case of deep infection following dry needling in the posterolateral knee of a 16-year-old male football player. Clean needle technique was documented, and treatment was reported in posterolateral thigh; approximately 10 days after treatment, an abscess was identified that was consistent with MSSA in the popliteal fossa. The player was reported to continue to play competitive sports during this time. Is this a case of clinician error in clean needle technique, or are these coincidental findings?
Uzar et al. reported an iatrogenic pneumothorax in a 36-year-old male. Pneumothorax was confirmed with CT scan two hours after dry needling of right thoracic region. Information was not presented regarding muscles or technique.
Berrigan et al. reported a case of acute spinal epidural hematoma following dry needling. Treatment sessions included cervical multifidi, infraspinatus, rhomboids and upper trapezius over three sessions spanning approximately ten days. After the fourth session, patient was seen at an urgent care facility for severe pain and was subsequently admitted to hospital several days later. This is the first published case report with a severe adverse event, to our knowledge.
Finally, McManus et al. recently reported radial nerve injury after dry needling. The patient reported a one-month history of wrist drop as noted by the orthopedist. This case was reported as treatment for shoulder pain, and severe spasm was noted after treatment in the lateral arm. No resolution of wrist drop was noted after full medical workup, including EMG and nerve conduction studies that showed no signs of recovery. It is important to note that there were few specifics provided on treatment dosage, location, or frequency.
The cases outlined make it clear that the potential for adverse events is significant yet variable in presentation. As the number of clinicians using dry needling continues to expand, safety and reduction of adverse events should be high priority. A thorough understanding of anatomy, skilled and standardized technique, and effective communication with the patient are essential.
Can we prevent adverse events?
It is unlikely that clinicians can fully avoid adverse events. However, from this author’s perspective, there are a variety of ways to minimize the potential for events, as described below.
When examining some of the causes of adverse events, here are a few trends that tend to play a large role.
Dosage: How much? How often? How long? The answers to these questions will vary among clinicians, but evidence suggests that perhaps less is more. Fernandez-Carnero et al. reported that outcomes were not significantly different when comparing the number of local twitch responses for treatment. There is good evidence to suggest that achieving a local twitch response creates better patient outcomes in treatment, as well as reducing pain pressure threshold. While the dosage of treatment is still debatable, it is this author’s opinion that the clinician should strive for a minimum effective dose. This can be achieved through specific and confident palpation and achieving a local twitch response.
2.Understanding of Anatomy and Refined Palpation Skills
Palpation is a constantly evolving skill for both the novice and experienced clinician. It requires consistency of training and acute attention to detail. Inadequate knowledge of bony landmarks and 3-dimensional anatomy combined with inappropriate needle safety will almost always lead to poor outcomes, and will produce increased risk for the patient. Palpation requires an extensive and competent understanding of anatomy, an area which commonly becomes under-trained as clinicians advance in practice. The importance of a competent anatomical understanding can minimize a large majority of adverse events.
It is this author’s recommendation that the clinician should minimize pistoning techniques until bony depth is achieved, completely understand anatomy of the area prior to implementing the needle, and maintain firm contact with the palpating hand to provide feedback and improved accuracy of the procedure. It is the clinician’s responsibility to continuously pursue knowledge of anatomy and palpation skills. This cannot be overstated.
3. Patient feedback and technique
Allowing the patient to maintain an active role in the treatment is vital to help prevent adverse events. The clinician should ask for consistent yet concise feedback throughout the session. These situations are often related to the insertion—specifically, the lack of direct pressure and speed of initial puncture, or possible contact with a cutaneous nerve or vessel. Several scenarios specific to such instances are listed below:
*A sharp sensation is reported by the patient with needle entry that remains sharp throughout the session.
Recommendation: Withdraw needle and re-palpate the treatment area. Contact with cutaneous nerve or vessel was likely.
*Needle entry that is sharp upon entry, then becomes generally dull and achy.
Recommendation: Pause upon patient report of sharp sensation. If it diminishes, proceed cautiously with treatment. The patient likely will tolerate the treatment with little side effect.
*An unremarkable needle entry followed by reports of sharp, electric pain in the path of peripheral nerve or dermatome.
Recommendation: Upon patient report of pain, pause and withdraw needle. Simple and concise explanation to patient. Pain report is often brief but subsides quickly with little side effect if recognized quickly. Continuation of treatment is patient dependent. This situation is often indicative of contact with nerve tissue.
4.Inadequate History and/or Incomplete Evaluation
A detailed history and thorough assessment are essential to the success of any intervention. Clinicians should be astute to the breadth of factors that can ultimately drive the patient’s complaints and/or pain. With that in mind, it is important to investigate these underlying and potentially psychosocial variables which may have impact on the evaluation and treatment. These variables should be considered with dosage, intensity, and frequency aspects of providing a needle-based treatment, as such treatments can often cause increased anxiety or fear due to the nature of the intervention itself. As with other interventions, it is equally important to select patients suitable for treatment as much as selecting for those that are appropriate.
Pain is a driver of sympathetic nervous system activity, which can create chronic physical adaptations. This includes assessing pain presentation and quality, as well as evaluation of general stressors, both physical and psychosocial. For the sympathetically driven patient, the likelihood of mild adverse events can be minimized by addressing these underlying mechanisms first. Strategies to drive down sympathetic activity include: patient education, breathing strategies, sleep hygiene education, aerobic exercise, and/or soft tissue mobilization. Keeping these strategies in mind, the likelihood of an adverse event in a sympathetically driven patient can be minimized.
As dry needling continues to grow in popularity, both clinically and academically, the reports of adverse events will continue to rise in the literature.
These reports, while essential, must be examined critically. The astute clinician must use these events as an opportunity to learn and help minimize the risk of future adverse events. While the current literature has reported several recent significant adverse events, it is this author’s recommendation that these reports should provide an opportunity for professional self-reflection as well as review of clinical technique and pertinent clinical anatomy.
Adam Weaver is a physical therapist with over 13 years of clinic experience; he now resides and practices in Farmington, CT, at Connecticut Children’s Medical Center Sports Physical Therapy. He has also been an assistant instructor for KinetaCore FDN 1 and FDN 2 courses since 2011.
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