Effectiveness of Electrical Neurostimulation as an Opioid-Sparing Alternative in the Treatment of Cyclic Vomiting Syndrome.

Opioid use in CVS and the critical need for opioid sparing therapy

Given the lack of knowledge about pathophysiology and evidence-based therapies, patients are often hospitalized to treat symptoms of CVS. During an episode, patients present with severe vomiting and abdominal pain and are treated empirically with IV fluids, antiemetics, benzodiazepines, and opioids. Estimates of opioid use range from 23%-27% in adults with CVS. Patients are often dissatisfied with the level of analgesia as recurrent opioid use results in tolerance and dependence. This often undermines the physician-patient relationship and patients even leave against medical advice out of frustration with what they perceive as ineffective care. This can lead to worse outcomes including recurrent hospitalizations, morbidity and increased health care costs.

Preliminary data from a study by our group reveals that of 101 patients hospitalized with CVS at Froedtert Hospital, chronic opioid therapy is associated with a two-fold increased risk of hospitalization (RR 2.22, CI 1.1-4.4, P=0.02) and three-fold increase in hospital length of stay (LOS) (RR 3.43, CI 1.26-9.34, P=0.01). In a study of 132 CVS patients, opioid use was associated with non-response to amitriptyline (53% vs 15%, p<0.05), a prophylactic therapy used in CVS. This in turn was associated with increased frequency and duration of CVS episodes per year and increased number of hospitalizations/emergency department (ED) visits at baseline (18% vs 15.2%, p<0.05). Hence there is an urgent need for an opioid-sparing, non-invasive strategy to treat CVS symptoms.

In summary, CVS is common and disabling and is associated with significant health care costs. Our proposed project using a novel, non-invasive device to treat CVS will also address the current opioid crisis.