This case series demonstrated significant relief for persistent hiccups, as well as significant reductions in discomfort, distress, and fatigue after acupuncture therapy. The effect of acupuncture for persistent hiccups in patients with cancer was measured using the HAI. This article presents a preliminary validation of the HAI and demonstrates its usefulness as a clinical and research instrument. The HAI was simple to administer, and the 0–10 numerical scale was familiar and easily understood by patients. To our knowledge, this is the first report of the use of a measurement instrument for hiccups severity. In repeated measurements, HAI responses indicated variability and significant change following acupuncture interventions. Thus, the HAI was not only useful in evaluating the patient's condition, but also provided evidence of the positive change in symptoms in response to acupuncture treatments.
The mechanisms for acupuncture's efficacy in treating hiccups remain unclear. Most acupoints for hiccups are located near dermatomes related to afferent/efferent pathways, secondary synapses, or nuclei involved in the hiccup reflex arc.21
Acupuncture might modulate any portion of the hiccup reflex arc locally by changing blood perfusion, activating the autonomic nervous system, regulating inflammatory mediators, or altering axonal excitability.22
It is also possible that acupuncture influences the hiccup center by modulating the secretion of neurotransmitters and neurohormones, such as endogenous opioids, norepinephrine, serotonin, substance P, and γ-aminobutyric acid.22,23
Sun et al. observed that acupuncture at ST36 and PC6 could activate discharges of the nucleus tractus solitarii neurons in the rat, and Ji et al. reported that moderate acupuncture stimulation of PC6, CV12, and ST36 could effectively activate discharges of the subnucleus reticularis dorsalis neurons in the rat.24,25
These same acupoints were also utilized in our study.
Acupuncture has been in clinical practice for over 3000 years in China, and its popularity in the United States and other parts of the Western world has been increasing since the late 1970s.26
Acupuncture's acceptance by non-Asian patients was also investigated in this study, and the results of the post-treatment evaluative questionnaire indicated that acupuncture was favorably viewed by all 16 subjects with varied sociodemographic backgrounds.
The Acupuncture Consult Service is open to all NIH patients with a wide range of diseases and symptoms. There was no referral bias from the requesting physicians. The subjects were all male patients with cancer receiving chemotherapy at the time of the study, and most had undergone surgery or stem cell transplantation as well. This suggests that there might be an association of persistent hiccups with cancer and cancer-related procedures or therapies, and that the male patients are more susceptible to persistent hiccups. These observations were confirmed in other reports.27,28
The occurrence of hiccups has a reported range of 30%–0.39% in patients with cancer undergoing chemotherapy with different drugs. The total incidence was much higher in males than in females.29
In this study, the mean hiccups severity score of 5.2 indicates that the patient's ADL were significantly impacted and highlights the need for medical attention. However, pharmacologic interventions might not succeed, might cause adverse effects, or might not be permitted by the research protocols. Acupuncture was therefore considered a better intervention. The patients enrolled in our study did not receive any interventions for hiccups for 24 hours prior to acupuncture treatment. In 1997, an NIH Consensus Development Conference on Acupuncture concluded that dental pain and nausea could be successfully treated with acupuncture.30
Statements issued in 2003 by the World Health Organization and in 2004 by the American Academy of Medical Acupuncture provided a longer list of indications for acupuncture, including hiccups.26
This study demonstrated that acupuncture treatment not only completely resolved persistent hiccups but also reduced fatigue, discomfort, and distress. Patients reported that hiccup-related symptoms also improved. Pharmacologic approaches for hiccups are not necessarily successful in related symptoms control and may even cause adverse effects.22
For example, 1 patient in our study was referred for acupuncture treatment because baclofen, a popular remedy for hiccups,11
had to be discontinued, due to side-effects of weakness, vomiting, and increased fatigue. After acupuncture therapy, the hiccups stopped and some of his other symptoms improved.
The safety of acupuncture was also evaluated in the study, and no serious adverse events occurred. Two (2) previous articles—one a study of the adverse effects of 32,000 acupuncture consultations and the other a prospective audit of acupuncture treatments of 1848 professional acupuncturists—have demonstrated that acupuncture is safe.31,32
Our evaluation showed that one to three acupuncture treatments resolved persistent hiccups completely in all patients who were able to complete the study. The same result was reported in two prior studies. However, those studies were limited to 1 and 2 patients, respectively.13,23
The rapid effectiveness of acupuncture also suggests that it is a cost-effective therapy for hiccups. Another previous study reported that acupuncture may provide long-term relief from hiccups through changes in neuronal gene expression that result in neuronal input modulation.33
A longer follow-up period than provided in our case series is needed to evaluate this finding. Case series with observational outcomes inherently have methodological limitations and confounding factors. Future randomized, blinded, controlled studies are needed to better understand the mechanisms of action.