Acupuncture for procedural pain in newborn infants

Objectives

This is a protocol for a Cochrane Review (intervention). The objectives are as follows:

To assess the benefits and harms of acupuncture in newborn infants undergoing painful procedures.

Background

Description of the condition

Newborns commonly experience invasive, painful procedures, such as blood collection and immunizations. Preterm or sick term newborns in the neonatal intensive care unit (NICU) experience a much higher frequency of invasive and painful procedures (Carbajal 2008). On average, premature babies requiring NICU admission encounter about 14 painful procedures daily while in the hospital (Johnston 2011). Some of these procedures are life‐saving, with no time to provide preventive analgesia, while other procedures are less urgent or planned in advance as part of routine care. Some procedures are frequently performed, including the heel stick or heel lance/needle prick (Courtois 2016). This procedure is a pinprick puncture into the heel of a newborn and is used to obtain blood samples for screening laboratory tests, glucose levels, general chemistries, complete blood counts, and toxicology screening. Generally, to obtain adequate amounts of blood for testing, the heel must be squeezed, which is considered painful (Shah 2011). Neonates commonly undergo other painful procedures that are considered both life‐saving and routine, including nasal/tracheal aspirations. There are procedures performed in neonates, that if performed in adults, would be considered extremely painful, such as endotracheal intubation, lumbar puncture and insertion of chest tubes (Carbajal 2008). Furthermore, necessary and vital examinations such as ophthalmological examination for retinopathy of prematurity are considered to cause pain, discomfort, and distress for the infants and are usually conducted without analgesia.

Infants who undergo repetitive episodes of untreated or under‐treated pain have adverse outcomes (Anand 1998). This is particularly concerning in preterm newborns, who are especially vulnerable to the negative effects of pain due to their immature nervous system (Maxwell 2019). Physiological alterations with acute procedural pain include cardiorespiratory and neuroendocrine stress responses, and changes in cortical activity (detected by near‐infrared spectroscopy and electroencephalography) (Slater 2006). These acute physiological pain responses may exacerbate or cause neurological injuries including intraventricular hemorrhage and periventricular leukomalacia in the sick and fragile preterm infant (Bouza 2009).

Repetitive procedural pain in neonates results in established or chronic pain and is associated with long‐term neurodevelopmental consequences. The effects include altered pain processing, pain sensitivity, response to pain, and lower cognitive and motor function (Ranger 2014). Repetitive pain exposure during infancy is associated with childhood behavioral and emotional changes, Vinall 2014, and difficulties with attention, learning, and social adaptation (Anand 1997).

Interventions for pain management can be classified as non‐pharmacological (e.g. swaddling positioning, skin‐to‐skin care, breastfeeding, oral sweet solutions, non‐nutritive sucking, and multisensory stimulation) or pharmacological. Non‐pharmacological strategies may mitigate the discomfort from less painful procedures but are usually not practical and are often ineffective for complex and protracted procedures, especially in very sick infants (Bembich 2018). It is increasingly understood that pharmacological agents, used to treat or prevent pain, have the potential to adversely affect the surviving newborn infant. For example, opioids have serious side effects including respiratory depression and hypotension (Hall 2005), and in animal and adult models, neurotoxicity, including increased neuronal death by apoptosis (Lee 2016). Moreover, opioids take time (e.g. up to 10 minutes) to exert their maximum effects, limiting their use in procedures needing rapid onset of analgesia.

Paracetamol may be hepatotoxic, especially in already compromised patients (Hall 2014). Eutectic mixture of local anesthetic (EMLA) has been associated with methemoglobinemia, particularly in preterm infants (Hall 2014). Sucrose is considered safe in the short term, but a study found that repetitive exposure to sucrose in preterm infants led to poorer motor and attention development at corrected term age (Hall 2014). Consequently, careful consideration must be used in administering analgesics to preterm infants, and non‐pharmacologic interventions are highly recommended.

Seeking alternative and safe forms of analgesia is therefore crucial to ensure optimum short‐ and long‐term well‐being of sick infants in the NICU.

Description of the intervention

Acupuncture, a field of traditional Chinese medicine, has been used for thousands of years to provide analgesia for a gamut of illnesses in adults (Vickers 2014). Acupuncture involves the stimulation of specific points on the body. Traditional forms of acupuncture involve inserting fine needles into specific cutaneous areas named acupuncture points. Potential complications of invasive acupuncture include infections, skin breakdown, and the development of hematomas, but no long‐term adverse effects have been reported (Raith 2013).

Invasive acupuncture normally involves needle retention, which is considered impractical in infants, especially those in the NICU. When invasive acupuncture is used on infants, insertion is generally shallow, and the needles are retained briefly or not at all (Ang 2021).

Electroacupuncture is a modified form that uses two needles. A mild electric current passes between these needles during treatment. This current generally applies more stimulation to acupuncture points than needle twirling or other hand manipulation techniques an acupuncturist might use.

Non‐invasive acupuncture or non‐insertive acupuncture (NIA) methods have been examined in newborn infants, including the use of laser acupuncture or non‐invasive electrical stimulation of acupuncture points (NESAP), acupressure, auricular non‐invasive magnetic acupuncture, and Japanese‐style teishin (Abbasoglu 2015; Gan 2020).

Laser acupuncture has been defined as "Photonic stimulation of acupuncture points and areas to initiate therapeutic effects similar to that of needle acupuncture and related therapies together with the benefits of PhotoBioModulation" (Lictscher 2018). Photobiomodulation therapy is defined as a form of light therapy that utilizes non‐ionizing light sources, resulting in beneficial therapeutic outcomes including the alleviation of pain (Cheng 2021).

Low‐level laser therapy is a light source treatment that emits no heat, sound, or vibration, but which may act via non‐thermal or photochemical reactions in cells (Basford 1989; Baxter 1999). In the past 35 years, as an alternative to using needles, practitioners have administered low‐level laser stimulation to acupuncture points via laser‐emitting devices applied to the skin (Moskvin 2020). In this technique, known as laser acupuncture, a laser beam generated by a low‐level laser diode stimulates the point. This method is painless and is especially suitable for awake children.

NESAP is an electrical, non‐invasive stimulation technique applied to acupuncture points with transcutaneous electrical nerve stimulation (TENS) devices (Yates 2013b).

In magnetic auricular acupuncture, small magnets are placed around specific points around the ear. The magnets can be left on the infant for days to preempt pain. The technique is non‐invasive and can easily be administered in a busy NICU setting. It is also ideal in situations requiring rapid delivery of effective non‐pharmacological analgesia (Gan 2020).

Acupressure is an ancient Chinese healing art that has been practiced for over 2000 years. In this pain‐relieving method, the fingers are used to press, massage, or both press and massage key acupuncture points on the skin surface that stimulate the body’s regulatory processes. Japanese‐style teishin is an NIA technique similar to acupressure where instead of a finger a small metal rod with a rounded tip or a dull point (teishin) is used to stimulate the acupuncture points. This technique is commonly used with pediatric patients (Filippelli 2012).

How the intervention might work

Traditional Chinese medicine has focused on the reduction of pain using acupuncture. Acupuncture is considered a key component in traditional Chinese medicine, which has been practiced for thousands of years and is considered to be one of the oldest healing practices in the world.

According to traditional Chinese theories, the channels circulate qi, blood, and body fluids to the body (Yao 2013). The concept of 'qi' is foreign to Western medicine and most closely relates to electromagnetic energy, signaling and metabolic processes within the body (Langevin 2002). There has not been consensus around the anatomical identification of the channel pathways in the body, though some theorize that the points lie along specific connective tissue, fascial planes, and interstitial spaces (Langevin 2002; Tomov 2020). A well‐known quote in Chinese medicine from the Huangdi Neijing, "不通則痛, 則通不痛, bùtōng zé tòng, zé tōng bù tòng," loosely translates to when there is obstruction there is pain, and when there is no obstruction there is no pain (Scheid 2018). The stimulation of acupuncture points is believed to help remove obstructions within the channels in order to relieve pain (Scheid 2018).

The Gate Control Theory of Pain is a prominent modern theory of how the stimulation of acupuncture points reduces pain (Melzack 1996). Acupuncture point stimulation activates A‐delta and c‐fiber, and sends signals to the spinal cord with the release of dynorphins and enkephalins; when these signals reach the mid‐brain, the excitatory and inhibitory mediators are activated and neurotransmitters are produced, causing pre‐ and postsynaptic inhibition of pain transmission (Katti 2014).

Moreover, it has been reported that levels of endogenous opiod‐like substances, such as endomorphin‐1, beta‐endorphin, enkephalin, and serotonin, increase in plasma and brain tissue after acupuncture or electroacupuncture application (Cabýoglu 2006). When an acupuncture needle is inserted, it stimulates pain receptors (nerve endings) and causes the secretion of endogenous opioids (Guyton 2007). Increased levels of these substances in plasma and brain tissue causes analgesia and sedation.

Needle retention is not required for acupuncture point stimulation, therefore less invasive techniques can be used with infants. Infants in particular are considered to respond quickly to any point stimulation, and it may be that NIA techniques like acupressure or Tuina massage are all that is necessary for effective treatment (Fan 1994). Tuina massage is similar to Shiatsu massage and is often used in conjunction with acupuncture and other traditional Chinese medicine interventions (Fang 2013). It acts on the body surface by various manipulations, such as rubbing, kneading, and pressing, to regulate the physiological and pathological state (Wang 2008).

Laser acupuncture, which is defined as stimulation of these traditional acupuncture points using a low‐level laser, is not only painless but is also non‐invasive, atraumatic, and easy to perform, with no risk of cross infections, and is appropriate for treating children. Evidence to explain how laser acupuncture might reduce pain is lacking; however, low‐intensity laser therapy studies provide some indication of indirect laser‐mediated effects on nerve tissue. Transdermal irradiation using a continuous wave, 40 mW, 830 nm laser (radiant exposure 9.6 J cm⁻²) demonstrated increased medial nerve conduction latency (Baxter 1994), which was associated with reduced skin temperature attributed to blood flow reduction (Lowe 1994). The small conduction delay reported (0.2 to 0.4 ms) may thus not have been caused by a direct nerve effect.

Magnetic auricular acupuncture has used points known to influence central pain perception (i.e. brainstem nuclei, thalamus, cingulate gyrus, and somatosensory cortex) through stimulation of auricular branches of cranial nerves 5 and 10 (Frangos 2015). Auricular stimulation of fibers of cranial nerve 10 might also modulate cardiovascular function and potentially improve physiological deterioration during painful procedures (Murray 2016).

Similarly, applying teishin or acupressure at acupuncture points may activate nociceptors, specialized peripheral sensory neurons that are sensitive to painful or damaging stimuli or to pressure to the skin (Guyton 2007). During the pain impulse, stimulation of neurons in the mesencephalon activates the analgesic system. Acupressure triggers the release of endorphins, norepinephrine, encephalin, and serotonin using similar transmission pathways, resulting in presynaptic inhibition of pain (Bear 2007). Many studies have demonstrated the effectiveness of acupressure for relieving pain in adults (Chen 2014).

Why it is important to do this review

Neonates in the NICU are a vulnerable patient population repeatedly exposed to painful procedures daily. Despite the advances made in the field of procedural pain management in neonates, much of the medication used today lacks clear guidelines and is associated with various adverse effects (Hall 2014). Careful consideration must therefore be taken in administering analgesics, and non‐pharmacologic interventions are highly recommended.

According to clinical, ethical, and policy statements, developing optimal treatment techniques to reduce neonatal pain is an important topic and challenge for neonatal caregivers (Anand 2001).

Alternative non‐pharmacological therapies, such as acupuncture and its variants: acupressure, laser acupuncture, and non‐invasive auricular acupuncture, have been described to treat procedural pain in newborns (Abbasoglu 2015; Ecevit 2011; Yates 2013a). Current studies are limited by small samples sizes and heterogeneous patient populations, disease states, and modes of treatment used (Abbasoglu 2015; Ecevit 2011; Yates 2013a). A recent review suggests that invasive and non‐invasive acupuncture techniques may have a positive pain‐relieving effect in neonates, but due to the low number of available high‐quality trials and heterogeneity across studies, it is not possible to provide clear recommendations (Stadler 2019). Based on limited evidence, no obvious adverse consequences of the use of either invasive or non‐invasive acupuncture modalities were found in both preterm and term infants (Chen 2017).

Previous Cochrane Reviews have focused on procedural pain management through the administration of pharmacological (Kinoshita 2023; Ohlsson 2020; Persad 2023; Romantsik 2020) and non‐pharmacological treatment (Harrison 2016; Johnston 2017). However, no systematic reviews have been conducted on acupuncture and its variants for the treatment of procedural pain. As the field of neonatal procedural pain management is constantly evolving, a better understanding of the evidence‐based options available is warranted to inform clinical practice.

Objectives

To assess the benefits and harms of acupuncture in newborn infants undergoing painful procedures.

Methods

Criteria for considering studies for this review

Types of studies

We will include randomized controlled trials (RCTs), quasi‐RCTs, cluster‐randomized trials, and cross‐over randomized trials.

We will exclude non‐randomized cohort studies, which are prone to bias due to confounding by indication or by residual confounding, both of which may influence the results of the studies (Fewell 2007; Kyriacou 2016).

Types of participants

We will include preterm and term infants of a postmenstrual age (PMA) up to 46 weeks and 0 days, irrespective of their gestational age at birth. The infants will be receiving acupuncture for procedural pain such as:

• during dialysis;

• extracorporeal membrane oxygenation (ECMO) treatment;

• before screening for retinopathy of prematurity;

• placement of Broviac catheter;

• air leak drainage;

• insertion of a central line;

• heel lance;

• lumbar puncture;

• venipuncture;

• arterial line placement; and

• any other painful procedures.

Types of interventions

We will include all forms of acupuncture therapy, involving either penetration of the skin with a needle, acupressure, or laser acupuncture and percutaneous ('invasive' (involving skin penetration) or 'non‐invasive' (non‐penetrative stimulation) neuromodulation).

Acupuncture may be given alone or in combination with other medical treatment for procedural pain, if the latter is also administered to the control group.

We will include trials evaluating all forms of acupuncture therapy that involves the penetration of the skin with needles, including scalp acupuncture, body acupuncture, auricular acupuncture, tongue acupuncture, injection acupuncture, or electro‐acupuncture, or any combination of the above, regardless of frequency of treatment, duration of the treatment period, and location(s) of stimulation (e.g. scalp, body, tongue, or ear would be included) (Wong 2013). However, evidence on the safety of using scalp, tongue, and injection acupuncture in infants is lacking. Most of the points used in tongue acupuncture are located on the sublingual area, and the possible bleeding and pain after the intervention may interfere with normal breastfeeding. The possibility of such harm is unclear due to lack of reporting. Safety information of scalp acupuncture, where a needle is inserted on the scalp tissues which are assumed to represent the brain somatotopy, in infants is unclear, and extra caution would be expected due to the possibility of incomplete closure of the skull bones.

We will include the following comparisons:

• invasive acupuncture (with needles), with or without electrical stimulation; or non‐invasive, with or without electrical stimulation (e.g. acupressure, laser acupuncture, NESAP, or TENS) versus no treatment;

• invasive acupuncture (with needles), with or without electrical stimulation; or non‐invasive, with or without electrical stimulation (e.g. acupressure, laser acupuncture, NESAP, or TENS) versus placebo or sham treatment;

• invasive acupuncture (with needles), with or without electrical stimulation; or non‐invasive, with or without electrical stimulation (e.g. acupressure, laser acupuncture, NESAP, or TENS) versus any pharmacologic treatment;

• acupuncture type A (e.g. penetration of the skin with a needle) versus acupuncture type B (e.g. acupressure).

We will exclude studies comparing different forms of acupuncture only (different manipulation methods or different acupuncture points) since these studies will not deduce the net effect of acupuncture and hence will be unable to demonstrate the efficacy of acupuncture per se (Wong 2013). In addition, we will exclude studies using different types of acupuncture or concomitant therapies as treatment package.

We will not exclude studies based on the frequency and duration of treatment.

Types of outcome measures

The following outcome measures do not form part of the eligibility criteria.

Primary outcomes

• Pain assessed with a validated scale for procedural pain in newborns (*). We plan to report the mean values of each pain scale assessed:

  • during the procedure;

  • up to 10 minutes after the procedure;

  • between 11 and 59 minutes; and

  • at one to two hours after the procedure.

If a study reports more than one time point among those specified above, we will report them all. We will report the worst score within each time frame.

• Any harms, e.g. infection, bleeding, bruising, needle‐related tissue damage, stuck needle, needle‐related pain. We will report harms as reported by study authors, and for the entire study duration.

*Validated scales: ABC scale (Bellieni 2005); Bernese Pain Scale for Neonates (Cignacco 2004 [https://revman.cochrane.org/#/586221061717423846/dashboard/htmlView/1.3.3?revertEnabled=true#REF‐Cignacco‐2004]); Behavioral Indicators of Infant Pain (BIIP) (Holsti 2008); Douleur Aiguë du Nouveau‐né (DAN) (Acute Pain in Newborn infants, APN, English version) (Carbajal 1997); Neonatal Infant Pain Scale (NIPS) (Lawrence 1993); Neonatal Pain, Agitation, and Sedation Scale (N‐PASS) (Hummel 2008); Premature Infant Pain Profile (PIPP)/PIPP‐revised (PIPP‐R) (Gibbins 2014; Stevens 1996).

If a study reports more than one pain scale among those specified above, we will report them separately.

Secondary outcomes

• Parental, family, and caregiver satisfaction with the intervention, as reported by study authors

• Use of additional pharmacological intervention for the relief of procedural pain

• Episodes of bradycardia, defined as a fall in heart rate of more than 30% below the baseline or less than 100 beats per minute for 10 seconds or longer

• Episodes of apnea (mean rates of apnea)

• Episodes of desaturation, defined as a decrease of arterial oxygen saturation (SpO₂) to less than 80%, with no minimum duration specified

• All‐cause neonatal mortality (death until postnatal day 28)

• All‐cause mortality during initial hospitalization

• Intraventricular hemorrhage (IVH; all (grade 1 or 2) or severe (grade 3 or greater) on cranial ultrasound, according to Papile classification) (Papile 1978)

• Late‐onset sepsis (with proven culture)

• Duration of hospital stay

• Major neurodevelopmental disability: cerebral palsy, developmental delay (Bayley Scales of Infant Development ‐ Mental Development Index Edition II (BSID‐MDI‐II; Bayley 1993), Bayley Scales of Infant and Toddler Development ‐ Edition III Cognitive Scale (BSITD‐III) (Bayley 2005), or Griffiths Mental Development Scale ‐ General Cognitive Index (GCI) (Griffiths 1954; Griffiths 1970)), assessment greater than two standard deviations (SDs) below the mean, intellectual impairment (intelligence quotient (IQ) greater than two SDs below the mean), blindness (vision less than 6/60 in both eyes), or sensorineural deafness requiring amplification (Jacobs 2013). We plan to separately assess data on children aged 18 to 24 months and those aged three to five years.

Search methods for identification of studies

The Cochrane Sweden Information Specialist developed a draft search strategy for PubMed (National Library of Medicine) in consultation with the review authors (Appendix 1). This strategy will be peer‐reviewed by an Information Specialist using the Peer Review of Electronic Search Strategies (PRESS) Checklist (McGowan 2016a; McGowan 2016b). The PubMed strategy will be translated, using appropriate syntax, for other databases.

A population filter developed by Cochrane Neonatal will be used. The RCT search filter for Ovid MEDLINE, as recommended by Cochrane Neonatal, will be adapted to the syntax of PubMed and used to identify randomized and quasi‐randomized studies. We will conduct searches for eligible trials with no language, publication year, publication type, or publication status restrictions.

Electronic searches

We will search the following databases:

• Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library (Wiley);

• MEDLINE via PubMed (1946 to present);

• Embase (1974 to present).

Searching other resources

We will identify trial registration records using CENTRAL and by independent searches of:

• US National Institutes of Health Ongoing Trials Register ClinicalTrials.gov (clinicaltrials.gov);

• World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (trialsearch.who.int/Default.aspx);

• ISRCTN registry (www.isrctn.com).

We will screen the reference lists of included studies and related systematic reviews for studies not identified by the database searches.

We will identify conference abstracts using CENTRAL and the following conference website: PAS (Pediatric Academic Societies) (www.pas-meeting.org/past-abstracts/) for the years 2017 to 2022.

We will search grey literature, such as reports, dissertations, theses, and conference abstracts, using the sources listed below. Search terms: 'acupuncture' in combination with 'neonatal' or 'newborn'.

• WHO website (www.who.int/) and WHO Library (IRIS) (apps.who.int/iris/)

• Center for Research Libraries (CRL) (catalog.crl.edu/search~S4)

• Open Access Theses and Dissertations (OATD) (oatd.org/)

• Swedish University Dissertations (www.dissertations.se/)

• Theses Canada (National Library of Canada’s records of PhD and Master’s theses from Canadian universities) (www.collectionscanada.gc.ca/thesescanada/)

• DART‐Europe (www.dart-europe.org/)

We will search for errata or retractions for included studies published on PubMed (www.ncbi.nlm.nih.gov/pubmed).

Data collection and analysis

We will use the standard methods of Cochrane Neonatal, as described below.

Selection of studies

We will download all titles and abstracts retrieved by the electronic searches to reference management software. Duplicates will be removed using reference management software and Covidence (Covidence). Two review authors (RC, RH) will independently conduct title and abstract review. Any disagreements between review authors will be resolved by discussion or by consultation with a third review author (GS).

We will retrieve the full texts of records deemed potentially relevant, and two review authors (RC, HAA) will independently assess the full texts to determine eligibility. Any disagreements between review authors will be resolved by discussion or by consultation with a third review author (JLO). We will document the reasons for excluding studies during full‐text review in a 'Characteristics of excluded studies' table. We will collate multiple reports of the same study so that each study, rather than each report or reference, is the unit of interest in the review; we will group related reports under a single study ID. We will also provide any available information on ongoing studies in 'Characteristics of ongoing studies' tables. We will record the study selection process in sufficient detail to complete a PRISMA flow diagram (Liberati 2009).

Data extraction and management

Two review authors (RC, HAA) will independently extract data using a data extraction form integrated with a modified version of the Cochrane Effective Practice and Organisation of Care group data collection checklist (Cochrane EPOC Group 2017). We will pilot the form within the review team using a sample of included studies.

We will extract the following characteristics from each included study:

• administrative details: study author(s); published or unpublished; year of publication; year in which study was conducted; presence of vested interest; details of other relevant papers cited;

• study characteristics: study registration, study design type, study setting, number of study centers and location; informed consent; ethics approval, completeness of follow‐up (e.g. greater than 80%);

• participants: number randomized, number lost to follow‐up/withdrawn, number analyzed, mean gestational age (GA), GA age range, mean chronological age (CA) or CA age range, inclusion criteria and exclusion criteria;

• interventions: initiation, modality, and duration of acupuncture;

• outcomes as mentioned above under Types of outcome measures.

We will resolve any disagreements by discussion.

We will describe ongoing studies identified by our search and document where available information such as the primary author, research question(s), methods, and outcome measures, together with the anticipated reporting date in the 'Characteristics of ongoing studies' table.

We will contact study investigators/authors for clarification or additional data as required. Two review authors (GS, MB) will use Cochrane statistical software Review Manager Web for data entry (RevMan Web 2022). We will replace any standard error of the mean (SEM) by the corresponding SD.

Assessment of risk of bias in included studies

Two review authors (RC, RH) will use the Cochrane risk of bias tool to independently assess the risk of bias (low, high, or unclear) of all included studies for the following domains (Higgins 2017).

• Sequence generation (selection bias)

• Allocation concealment (selection bias)

• Blinding of participants and personnel (performance bias)

• Blinding of outcome assessment (detection bias)

• Incomplete outcome data (attrition bias)

• Selective reporting (reporting bias)

• Any other bias

Any disagreements will be resolved by discussion or by consultation with a third review author (GMS). A more detailed description of risk of bias for each domain is given in Appendix 2.

Measures of treatment effect

Dichotomous data

We will present results using risk ratios (RR) and risk differences (RD) with 95% confidence intervals (CIs). We will calculate the number needed to treat for an additional beneficial outcome (NNTB) or number needed to treat for an additional harmful outcome (NNTH) with 95% CIs if there is a statistically significant reduction (or increase) in RD.

Continuous data

We will use the mean difference (MD) when outcomes were measured in the same way between trials. We will use the standardized mean difference (SMD) to combine trials that used different methods to measure the same outcome. Where trials reported continuous data as median and interquartile range (IQR) and data passed the test of skewness, we will convert median to mean and estimate the SD as IQR/1.35.

Unit of analysis issues

The unit of analysis will be the participating infant in individually randomized trials, and an infant will be considered only once in the analysis. The participating neonatal unit or section of a neonatal unit or hospital will be the unit of analysis in cluster‐randomized trials. For cluster‐randomized trials, we will abstract information on the study design and unit of analysis for each study, indicating whether clustering of observations is present due to allocation to the intervention at the group level or clustering of individually randomized observations (e.g. patients within clinics). We will abstract available statistical information needed to account for the implications of clustering on the estimation of outcome variances, such as design effects or intracluster correlations (ICCs), and whether the study adjusted results for the correlations in the data. In cases where the study did not account for clustering, we will ensure that appropriate adjustments are made to the effective sample size following Cochrane guidance (Higgins 2022). Where possible, we will derive the ICC for these adjustments from the trial itself, or from a similar trial. If an appropriate ICC is unavailable, we will conduct sensitivity analyses to investigate the potential effect of clustering by imputing a range of values of ICC.

If any trials have multiple arms that are compared against the same control condition that will be included in the same meta‐analysis, we will either combine groups to create a single pair‐wise comparison or select one pair of interventions and exclude the others.

In the meta‐analysis and data synthesis, we will only include first‐phase data from cross‐over trials.

Dealing with missing data

We intend to carry out analysis on an intention‐to‐treat basis for all outcomes. Whenever possible, we will analyze all participants in the treatment group to which they had been randomized, regardless of the actual treatment received. If we identify important missing data (in the outcomes) or unclear data, we will contact the original investigators to request the missing data. We will make explicit the assumptions of any methods used to deal with missing data. We will perform sensitivity analyses to assess how sensitive results are to reasonable changes in the undertaken assumptions. We will address the potential impact of missing data on the findings of the review in the 'Discussion' section.

Assessment of heterogeneity

We will describe the clinical diversity and methodological variability of the evidence narratively and in tables. Tables will include data on study characteristics such as design features, population characteristics, and intervention details.

To assess statistical heterogeneity, we will visually inspect forest plots and describe the direction and magnitude of effects and the degree of overlap between CIs. We will also consider the statistics generated in forest plots that measure statistical heterogeneity. We will use the I² statistic to quantify inconsistency among the trials in each analysis. We will also consider the P value from the Chi² test to assess if this heterogeneity is significant (P < 0.1). If we identify substantial heterogeneity, we will report the finding and explore possible explanatory factors using prespecified subgroup analysis.

We will grade the degree of heterogeneity as:

• 0% to 40%: might not represent important heterogeneity;

• 30% to 60%: may represent moderate heterogeneity;

• 50% to 90%: may represent substantial heterogeneity;

• more than 75%: may represent considerable heterogeneity.

We will use a rough guideline to interpret the I² value rather than a simple threshold, and our interpretation will consider that measures of heterogeneity (I² and Tau²) will be estimated with high uncertainty when the number of studies is small (Deeks 2022).

Assessment of reporting biases

We will assess reporting bias by comparing the stated primary outcomes and secondary outcomes and the reported outcomes. Where study protocols are available, we will compare these to the full publications to determine the likelihood of reporting bias. We will document if studies use the interventions in a potentially eligible infant population but do not report any of our primary and secondary outcomes in the 'Characteristics of included studies' tables.

We will use funnel plots to screen for publication bias where there are a sufficient number of studies (> 10) reporting the same outcome. If publication bias is suggested by a significant asymmetry of the funnel plot on visual assessment, we will incorporate this in our assessment of the certainty of evidence (Egger 1997). If our review includes few studies eligible for meta‐analysis, the ability to detect publication bias will be largely diminished, and we will simply note our inability to rule out possible publication bias or small‐study effects.

Data synthesis

If we identify multiple studies considered to be sufficiently similar, we will perform meta‐analysis using Review Manager Web (RevMan Web 2022). For categorical outcomes, we will calculate the typical estimates of RR and RD, each with its 95% CI; for continuous outcomes, we will calculate the MD or the SMD, each with its 95% CI. We will use a fixed‐effect model to combine data where it is reasonable to assume that studies were estimating the same underlying treatment effect. If we judge meta‐analysis to be inappropriate, we will analyze and interpret individual trials separately. If there is evidence of clinical heterogeneity, we will attempt to arrive at an explanation for it based on the different study characteristics and subgroup analyses.

Subgroup analysis and investigation of heterogeneity

We will interpret tests for subgroup differences in effects with caution given the potential for confounding with other study characteristics and the observational nature of the comparisons. See Section 10.11.2 of the Cochrane Handbook for Systematic Reviews of Interventions (Deeks 2022). In particular, subgroup analyses with fewer than five studies per category are unlikely to be adequate to ascertain a valid difference in effects and will not be highlighted in our results. When subgroup comparisons are possible, we will conduct stratified meta‐analysis and a formal statistical test for interaction to examine subgroup differences that could account for effect heterogeneity (e.g. Cochran’s Q test, meta‐regression) (Borenstein 2013; Deeks 2022).

Given the potential differences in the intervention effectiveness related to gestational age, type of procedural pain, and type of acupuncture and discussed in the Background, we will conduct subgroup comparisons to see if the intervention is more effective.

We plan to carry out the following subgroup analyses of factors that may contribute to heterogeneity in the effects of the intervention:

• gestational age: extremely preterm (less than 28 weeks); very preterm (less than 32 weeks);

• type of procedural pain: e.g. during dialysis, ECMO treatment, before screening for retinopathy of prematurity, placement of Broviac catheter, air leak drainage, insertion of a central line, heel lance, lumbar puncture, venipuncture, arterial line placement;

• type of acupuncture: invasive or non‐invasive, with or without electrical stimulation.

We will use the main outcomes (those specified for the summary of findings table, as described below) in subgroup analyses if there are enough studies reporting to support valid subgroup comparisons (at least five studies per subgroup).

Sensitivity analysis

We will conduct sensitivity analyses to explore the effect of the methodological quality of studies, and check to ascertain whether studies with a high risk of bias (in at least two domains) overestimate the effect of treatment. Differences in study design of the included studies might also affect the results of the systematic review. We will perform a sensitivity analysis to compare the effects of acupuncture in truly randomized trials as opposed to quasi‐randomized trials.

Summary of findings and assessment of the certainty of the evidence

We will use the GRADE approach, as outlined in the GRADE Handbook (Schünemann 2013), to assess the certainty of evidence for the following (clinically relevant) outcomes.

• Pain assessed with a validated scale for procedural pain in newborns. We plan to report the mean values of each pain scale assessed:

  • during the procedure;

  • up to 10 minutes after the procedure;

  • between 11 and 59 minutes; and

  • at one to two hours after the procedure.

• Any harms, e.g. infection, bleeding, bruising, needle‐related tissue damage, stuck needle, needle‐related pain. We will report harms as reported by study authors, and for the entire study duration.

• Parental, family, and caregiver satisfaction with the intervention, as reported by study authors.

• Use of additional pharmacological intervention for the relief of procedural pain.

• Episodes of bradycardia, defined as a fall in heart rate of more than 30% below the baseline or less than 100 beats per minute for 10 seconds or longer.

• Episodes of apnea (mean rates of apnea).

• Episodes of desaturation, defined as a decrease of arterial oxygen saturation (SpO₂) to less than 80%, with no minimum duration specified.

Two review authors (RC, MB) will independently assess the certainty of the evidence for each of the outcomes listed above. We will consider evidence from RCTs as high certainty, downgrading one level for serious (or two levels for very serious) limitations based upon the following: design (risk of bias), consistency across studies, directness of the evidence, precision of estimates, and presence of publication bias. We will use GRADEpro GDT software to create a summary of findings table to report the certainty of the evidence (GRADEpro GDT).

The GRADE approach results in an assessment of the certainty of a body of evidence as one of the following four grades.

• High: we are very confident that the true effect lies close to that of the estimate of the effect.

• Moderate: we are moderately confident in the effect estimate: the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different.

• Low: our confidence in the effect estimate is limited: the true effect may be substantially different from the estimate of the effect.

• Very low: we have very little confidence in the effect estimate: the true effect is likely to be substantially different from the estimate of effect.

Appendices

Appendix 1. PubMed search strategy

Information Specialist: Maria Björklund

Affiliation: Lund University, Faculty of Medicine, Library & ICT, Sweden

PICO(s)

Patients
Neonates

Intervention

Acupuncture for procedural pain

Control

See protocol

Outcomes

See protocol

Study design(s)

RCTs and quasi‐ RCTs, cluster RCTs.

Search strategy

PubMed (National Library of Medicine)

Date of updated search: 2023, August 7

No publication date limitations or language limitations were used.

#1 "Infant, Newborn"[Mesh] OR "Intensive Care, Neonatal"[Mesh] OR "Intensive Care Units, Neonatal"[Mesh] OR "Gestational Age"[Mesh]
724229 records

#2 (babe[Text Word] OR babes[Text Word] OR baby*[Text Word] OR babies[Text Word] OR gestational age*[Text Word] OR infant*[Text Word] OR infantile[Text Word] OR infancy[Text Word] OR low birth weight[Text Word] OR low birthweight[Text Word] OR neonat*[Text Word] OR neo‐nat*[Text Word] OR newborn*[Text Word] OR new born?[Text Word] OR newly born[Text Word] OR premature[Text Word] OR pre‐mature[Text Word] OR pre‐matures[Text Word] OR prematures[Text Word] OR prematurity[Text Word] OR pre‐maturity[Text Word] OR preterm[Text Word] OR preterms[Text Word] OR pre term*[Text Word] OR preemie[Text Word] OR preemies[Text Word] OR premies[Text Word] OR premie[Text Word] OR VLBW[Text Word] OR VLBWI[Text Word] OR VLBW‐I[Text Word] OR VLBWs[Text Word] OR LBW[Text Word] OR LBWI[Text Word] OR LBWs[Text Word] OR ELBW[Text Word] OR ELBWI[Text Word] OR ELBWs[Text Word] OR NICU[Text Word] OR NICUs[Text Word])

1840639 records

#3 #1 OR #2

1840639 records
[Population‐Cochrane Neonatal standard filter for neonatal population, converted for PubMed, https://neonatal.cochrane.org/Literature-Search-Filters-for-Neonatal-Reviews ]

[Intervention]

#4 "Acupuncture Therapy"[Mesh] OR "Acupuncture"[Mesh] OR "Acupuncture Points"[Mesh] OR "Acupuncture Analgesia"[Mesh] OR "Acupuncture, Ear"[Mesh] OR "Meridians"[Mesh]

29936 records

#5 Acupunct*[TW] OR acupoint*[TW] OR acupressure*[TW] OR catgut embedding[TW] OR electroacupuncture*[Text word] OR electro‐acupuncture*[TW] OR pharmacopuncture[TW] OR meridian*[TW] OR transcutaneous electric nerve stimulation[TW] OR NESAP[TW] OR Neuromodulat*[TW] OR electric stimulation therap*[TW] OR neuroelectric therap*[TW] OR neuro‐electric therap*[TW] OR teishin[TW] OR "dry needling"[TW]

91125 records

#6 #4 OR #5
91831 records

[Study design filter‐ Cochrane Neonatal standard study design filter, adapted for PubMed https://neonatal.cochrane.org/Literature-Search-Filters-for-Neonatal-Reviews]

#7 randomized controlled trial [pt] OR controlled clinical trial [pt] OR randomized [tiab] OR placebo [tiab] OR drug therapy [sh] OR randomly [tiab] OR trial [tiab] OR groups [tiab]
5802962 records

#8 quasirandom*[tw] OR quasi‐random*[tw] OR random*[tw]

1684679 records

#9 control*[tw] AND (group[tw] OR groups[tw] OR trial[tw] OR trials[tw] OR study[tw])

3898812 records

#10 #7 OR #8 OR #9
793506 records

#11 (animals [mh] NOT humans [mh])

5143205 records

#12 #10 NOT #11

6814966 records

[Combination search‐ population AND intervention AND RCTs]

#13 #3 AND #6 AND #12

729 records

Appendix 2. RoB 1 tool

We will use the standard methods of Cochrane and Cochrane Neonatal to assess the methodological quality of the trials. For each trial, we will seek information regarding the method of randomization, blinding, and reporting of all outcomes of all the infants enrolled in the trial. We will assess each criterion as being at a low, high, or unclear risk of bias. Two review authors will separately assess each study, with any disagreements resolved by discussion. We will add this information to the 'Characteristics of included studies' table. We will evaluate the following issues and enter the findings into the risk of bias table.

Sequence generation (checking for possible selection bias). Was the allocation sequence adequately generated?

For each included study, we will categorize the method used to generate the allocation sequence as:

• low risk (any truly random process, e.g. random number table; computer random number generator);

• high risk (any non‐random process, e.g. odd or even date of birth; hospital or clinic record number); or

• unclear risk.

Allocation concealment (checking for possible selection bias). Was allocation adequately concealed?

For each included study, we will categorize the method used to conceal the allocation sequence as:

• low risk (e.g. telephone or central randomization; consecutively numbered, sealed, opaque envelopes);

• high risk (open random allocation; unsealed or non‐opaque envelopes, alternation; date of birth); or

• unclear risk.

Blinding of participants and personnel (checking for possible performance bias). Was knowledge of the allocated intervention adequately prevented during the study?

For each included study, we will categorize the methods used to blind study participants and personnel from the knowledge of which intervention a participant received. We will assess blinding separately for different outcomes or class of outcomes. We will categorize the methods as:

• low, high, or unclear risk for participants; and

• low, high, or unclear risk for personnel.

Blinding of outcome assessment (checking for possible detection bias). Was knowledge of the allocated intervention adequately prevented at the time of outcome assessment?

For each included study, we will categorize the methods used to blind outcome assessment. We will assess blinding separately for different outcomes or class of outcomes. We will categorize the methods as:

• low risk for outcome assessors;

• high risk for outcome assessors; or

• unclear risk for outcome assessors.

Incomplete outcome data (checking for possible attrition bias through withdrawals, dropouts, protocol deviations). Were incomplete outcome data adequately addressed?

For each included study and for each outcome, we will describe the completeness of data including attrition and exclusions from the analysis. We will note whether attrition and exclusions were reported, the numbers included in the analysis at each stage (compared with the total randomized participants), reasons for attrition or exclusion where reported, and whether missing data were balanced across groups or were related to outcomes. Where sufficient information is reported or supplied by the trial authors, we will re‐include missing data in the analyses. We will categorize the methods as:

• low risk (< 20% missing data);

• high risk (≥ 20% missing data); or

• unclear risk.

Selective reporting bias. Are reports of the study free of the suggestion of selective outcome reporting?

For each included study, we will describe how we investigated the possibility of selective outcome reporting bias and what we found. For studies in which study protocols were published in advance, we will compare the prespecified outcomes versus outcomes reported in the published results. If the study protocol was not published in advance, we will contact study authors to gain access to the study protocol. We will assess the methods as:

• low risk (where it is clear that all of the study's prespecified outcomes and all expected outcomes of interest to the review have been reported);

• high risk (where not all the study's prespecified outcomes have been reported; one or more reported primary outcomes were not prespecified outcomes of interest and are reported incompletely and so cannot be used; the study fails to include results of a key outcome that would be expected to have been reported); or

• unclear risk.

Other sources of bias. Was the study apparently free of other problems that could put it at high risk of bias?

For each included study, we will describe any important concerns we had about other possible sources of bias (e.g. whether there was a potential source of bias related to the specific study design, or whether the trial was stopped early due to some data‐dependent process). We will assess whether each study was free of other problems that could put it at risk of bias as:

• low risk;

• high risk; or

• unclear risk.

If needed, we will explore the impact of the level of bias by undertaking sensitivity analyses.

Contributions of authors

RC: produced the first draft; contributed to writing and editing of the protocol; made an intellectual contribution to and approved the final version of the protocol prior to submission.

GS, HAA, RH, JLO, GMS: developed, contributed to writing and editing, made an intellectual contribution to, advised on, and approved the final version of the protocol prior to submission.

MB: conceived the review question, made an intellectual contribution to, advised on, and approved the final version of the protocol prior to submission; is a guarantor of the protocol.

Sources of support

Internal sources

• Institute for Clinical Sciences, Lund University, Lund, Sweden

  MB is employed by this organization.

External sources

• Region Skåne, Skåne University Hospital, Lund University and Region Västra Götaland, Sweden

  Cochrane Sweden is supported from Region Skåne, Skåne University Hospital, Lund University and Region Västra Götaland.

• Vermont Oxford Network, USA

  Cochrane Neonatal Reviews are produced with support from Vermont Oxford Network, a worldwide collaboration of health professionals dedicated to providing evidence‐based care of the highest quality for newborn infants and their families.

Declarations of interest

RC has no conflicts of interest to declare.

GS works as a licensed Acupuncturist in a private practice, And Acupuncture PLLC, and volunteers on the board for the Vermont Acupuncture Association; these roles have not impacted his participation in this protocol, and the organizations have no vested interests in the findings of the review which will follow this protocol.

HAA has no conflicts of interest to declare.

RH has no conflicts of interest to declare.

JLO has no conflicts of interest to declare.

GMS is an Associate Editor with the Cochrane Neonatal Group, but took no part in the acceptance or editorial processes for this review.

MB is an Associate Editor with the Cochrane Neonatal Group, but took no part in the acceptance or editorial processes for this review.

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