The study is a single-center, double-blind, randomized protocol comparison. The study will be conducted in Marmara University School of Medicine Pendik Training and Research Hospital, Department of Emergency Medicine between April 2020 and October 2020.

The population consists of non-pregnant, adult patients (age of 18 or more) who will be confirmed as migraine according to The International Classification of Headache Disorders 3rd edition (ICHD-3) in the emergency department (ED). After the patient was found suitable for the standard treatment protocol, they will be randomized to receive a 1000 ml bolus of normal saline for 1 hour or normal saline at 10 cc/h for 1 hour. The pain level, functional status, and side effects will be assessed before the beginning, at the 1st hour, 2nd hour and at the 24th hour.

The objective of this study is to determine the effect of an intravenous (IV) fluid bolus on migraine headache among patients treated in the ED.

Introduction Headache is a common complaint that is seen in 70-80% of the population and is a common health problem in emergency services. When evaluating the patient with headache, the first step is to determine whether the headache is primary or secondary (1, 2). Primary headaches are classified according to their symptoms and clinical features. Tension-type headache, migraine, and cluster headache are the most common types of primary headaches (3). Secondary headaches can be classified as headaches due to the head and neck trauma, headaches secondary to neurovascular diseases, and headaches due to withdrawal syndromes secondary to drug abuse (4). Migraine is a primary type of headache characterized by recurrent throbbing (usually unilateral) and associated with photophobia, phonophobia, nausea, and other symptoms. Patients with migraine are usually not pleased with the treatment options due to headaches refractory to treatment (5).

The current approach to the treatment of migraine headaches consists of two components: treatment of the acute migraine attacks, and prophylactic treatment.

According to the World Health Organization (WHO), migraine attacks are the eighth cause of loss of work and performance in the attack period among all lifelong diseases (12). Therefore, effective treatment of migraine attacks is important for the patient and socioeconomic wellbeing of the community. More than 90% of the migraine patients experience acute migraine attacks despite prophylactic treatment and need pain medications (6). Common treatment options used in the ED are phenothiazines (7), serotonin receptor agonists (8), and corticosteroids (9). Headache guideline of the American Academy of Neurology published in 2000 also recommends diclofenac as an effective alternative for the treatment of acute migraine attacks (10, 11). Effective attack therapy has the potential to significantly reduce inefficiency caused by migraine attacks by shortening the duration and reducing the severity of attacks.

Although clinical evidence is uncertain, approximately 40% of patients presenting to the ED with a headache are treated with IV fluids (13). Studies with healthy volunteers showed that mild dehydration reduces the pain threshold and increases central pain-related activity in the anterior cingulate cortex, insula, and thalamus (14). Therefore, it is logical to think that dehydration may trigger acute migraine attacks (15). This led to the common approach to use IV fluids besides pain medications in the ED as a routine procedure. A clear benefit would obviously increase the satisfaction of the patient from the ED services, by increasing the pain threshold, decreasing length of stay, and need for rescue treatment. However, on the contrary, IV fluid therapy without an obvious benefit to the patient has a cost burden on the system, uses labor and time of the ED staff, and may increase the duration of the length of stay in the ED.

Therefore, the aim of this study is to evaluate the efficacy and side effects related to the addition of 1000 cc bolus NS to the standard treatment of migraine in the ED.

Inclusion criteria:

• age 18 years or older
• migraine with or without aura according to International Classification of Headache Disorders-3 (ICHD-3) diagnostic criteria confirmed by one-to-one physical exam in the ED
• no declaration and sign of pregnancy, or pregnancy not diagnosed during the ED evaluation before randomization,
• did not receive any IV fluid of 100 cc or more at any facility in the last 12 hours,
• intramuscular diclofenac potassium 75 mg, the standard treatment protocol, is ordered by the physician (no history of known allergic reaction to diclofenac potassium),
• severe dehydration not present as determined by the researcher (hypotension, dry mouth, tongue and eyeballs, decreased urine output)
• no other indication for fluid infusion,
• no contraindication to fluid administration (heart failure patients with diuretic use, renal failure patients with fluid restriction, hemodynamic instability),
• do not have accompanying symptoms and signs related to headaches secondary to other obvious pathologies rather than migraine,
• consent to be included in the study.

Exclusion criteria: no patients will be excluded from the study after randomization. All patients will be evaluated for the primary outcome with an intent-to-treat approach.

The fluid bag, intravenous pump, serum set will be concealed with opaque coaters, so that patients, doctors, and study investigators will be blinded to the treatment group. Only the nurse who sets the infusion pump will be aware of the treatment group of the patient.