Invasive and non-invasive acupuncture techniques for pain management in neonates: a systematic review

Pain management in newborn infants represents one of the major challenges of modern neonatal medicine. Until recently, it was believed that newborns did not experience pain because of the immaturity of their nervous system. We now know this is not true — studies show that infants are capable of experiencing both the sensory and emotional aspects of pain, since brain regions that process pain in adults are already active in newborns. More concerning still, painful and stressful experiences can negatively affect ongoing neurological development, potentially increasing pain sensitivity later in life.

During hospitalization, both preterm and term infants undergo numerous painful procedures necessary for diagnosis and treatment, with heel-stick blood collection being one of the most common. Currently, oral sweet solutions are the gold standard for pain relief during minor procedures, but other effective non-pharmacological options are limited, creating an urgent need to develop additional gentle and safe strategies.

Acupuncture has emerged as a promising non-pharmacological technique for pain management in children and newborns. This ancient medical practice stimulates body tissues through needles, laser, pressure, or non-invasive electrical stimulation. Extensive research in adults and animals has revealed that acupuncture analgesia involves both central and peripheral effects, modulating activity in multiple brain areas including the brainstem, cerebellum, and limbic system. The pain-reducing effects may also be related to increased local blood flow following stimulation, accelerating the clearance of natural analgesic substances.

Studies show that manual acupuncture and electroacupuncture increase blood flow through elevation of nitric oxide levels and release of vasodilatory peptides. In children and infants, preliminary studies have demonstrated an analgesic effect of acupuncture, which has been described as a safe technique in newborns, even affecting cerebral oxygen saturation.

This systematic study aimed to review the available evidence on acupuncture techniques for pain reduction in neonates undergoing painful procedures during routine medical care. Researchers conducted a comprehensive search of medical databases from inception through February 2017, including MEDLINE, Embase, CINAHL, clinical trial registry platforms, and reference lists. Inclusion criteria were studies with preterm or term newborns, use of acupuncture for painful medical interventions, and formal pain assessment as a primary or secondary outcome. Only randomized controlled trials were included.

The acupuncture modalities considered included needle acupuncture, superficial puncture, acupressure, laser acupuncture, non-invasive electrical stimulation of acupuncture points, and moxibustion. Two reviewers independently performed study selection, data extraction using a standardized protocol, and individual risk-of-bias assessment.

The initial search yielded 12,196 records. After rigorous application of inclusion criteria, five studies were included in the review. All used heel lance as the painful intervention, but they varied significantly in acupuncture modalities, selected points, control groups, and pain assessment methods. Three studies used the Premature Infant Pain Profile (PIPP) and two used the Neonatal Infant Pain Scale (NIPS) to assess pain intensity.

Two studies demonstrated significant pain reduction: laser acupuncture at 30 mW applied for 30 seconds at specific points on the hand and ear showed significant reduction compared with placebo laser, and superficial needle puncture for 30 seconds at a specific facial point significantly reduced pain scores compared with standard care. One study found equivalent results between 3-minute acupressure at points on the foot and routine care. Two studies showed significantly higher pain scores with acupuncture alone: low-power laser acupuncture was inferior to oral sucrose solution, and non-invasive electrical stimulation alone was less effective, being effective only when combined with oral sucrose.

The results suggest that acupuncture may have a positive effect on pain relief in newborns, but the clinical implications must be interpreted cautiously. For patients and families, these findings indicate that acupuncture may represent an additional non-pharmacological option for pain management during minor procedures, potentially complementing existing strategies such as sweet solutions. Acupuncture has been shown to be safe in pediatric studies, with no fatal side effects reported, and may be especially valuable in situations where multiple procedures are needed, since repeated use of sweet solutions can lead to decreased efficacy. For health professionals, the results suggest that specific acupuncture techniques, particularly laser acupuncture with appropriate parameters and superficial puncture at selected points, can be integrated into neonatal pain management protocols.

However, clinical implementation requires adequate training in pediatric acupuncture techniques and an understanding of the different technical parameters that influence efficacy.

The main limitations include high heterogeneity across studies in acupuncture modalities, point selection, control groups, and pain assessment, preventing meta-analysis of the results. The small number of high-quality studies available limits the ability to make definitive recommendations. Significant methodological differences, such as variations in laser energy dosage, stimulation duration, and pain assessment techniques, hinder direct comparisons. Safety aspects were inadequately reported in most studies, with only one clearly stating the absence of adverse events.

The impossibility of blinding in some modalities such as acupressure may have influenced results. Although promising, these findings highlight the need for more standardized research examining side effects associated with acupuncture, safety, and long-term effects, as well as direct comparisons between different acupuncture modalities and points to establish optimal protocols for neonatal pain relief.