Acupuncture for the Prevention of Emergence Delirium in Children Undergoing Myringotomy Tube Placement

Myringotomy tube placement is one of the most commonly performed operations in children, with almost 700,000 completed in the United States each year 1. Common anesthetic management of these cases includes inhalational anesthesia and no intravenous line placement. Sevoflurane is the inhalational agent used most commonly for induction and maintenance of these patients. Emergence delirium after sevoflurane maintenance is common. In a study of children receiving sevoflurane-based anesthetic for MRIs, 47.6% of participants had emergence agitation 2. In a comparison of different emergence delirium scales, Bajwa and colleagues detected emergence delirium in 32% of subjects using the Pediatric Anesthesia Emergence Delirium (PAED) scale 3. Emergence delirium can be distressing for both children and their caregivers. During emergence delirium children can become both a danger to themselves and others around them, including family members and hospital staff. Emergence delirium can also delay discharge from the post-operative care unit (PACU).

There has been some published evidence that intraoperative acupuncture can decrease the incidence of post-operative delirium. One study enrolled 60 children undergoing bilateral ear tube placement and randomized half of the patients to receive acupuncture at points LI-4 (he gu) and HT-7 (shen men). The acupuncture group had a lower incidence of emergence agitation than the control group at time of arrival in the PACU and during the following 30 minutes 4. This study did not include patients that had received pre-medication with midazolam. It also did not use a validated assessment for emergence delirium in children.

A small retrospective review of 12 children that received acupuncture found that 83% did not show signs of emergence delirium. These patients had needling at 3 locations (SP 6, HT 7, Liv 3) and magnets placed at the ear shen men area. The anesthetic technique used for these patients was not standardized and there was no comparison group.

The primary objective of this study is to determine if acupuncture, when used in combination with standard anesthetic management, decreases the incidence of emergence delirium in pediatric patients following myringotomy tube placement. Patients with and without premedication of midazolam will be included as it is common that children receive sedating medications to facilitate separation from their caregivers.

A secondary objective of this study is to determine our institution's actual incidence of emergence delirium after this operation. We can also compare rates of emergence delirium with or without premedication of midazolam. Emergence delirium will be evaluated using a validated pediatric delirium scale. The Pediatric Anesthesia Emergence Delirium (PAED) scale has been tested for reliability and validity in 50 children 5.

Study Design We plan to explore this question with a randomized double blinded trial of acupuncture in children who are undergoing myringotomy tube placement. Patients will be randomized to receive either acupuncture immediately after anesthesia induction (A) or to receive standard anesthetic care only (S). Patients, their family members and recovery registered nurses (RNs) will not know if acupuncture was performed. The researchers observing the patients in the PACU will also be blinded to whether or not the subject received acupuncture. Intraoperative anesthetic techniques will be standardized, including administering the usual pain medication of ketorolac 0.5mg/kg given intramuscularly to each patient prior to emergence. Needles will be placed after anesthesia induction and removed prior to leaving the operating room. A total of 4 needles will be placed, one in each wrist at the HT7 point and one in each ear at the shen men point. Emergence delirium will be assessed with the Pediatric Anesthesia Emergence Delirium (PAED) scale. A follow up phone call will be made on the first post-operative day (POD #1). We will assess continued emergence delirium after discharge from the PACU, as well as a brief assessment on sleeping patterns the night after surgery. A second follow-up phone call will be made one week after surgery. During that call, we will ask about the child's behavior and sleep patterns since the time of surgery.

We do not know our institution's actual incidence of emergence delirium for this operation. We will assume it to be 25% as suggested by the literature. We do not know the effects of pre-medication with midazolam on the incidence of emergence delirium. We will assume a standard deviation of 4, a value consistent with the current published literature. By enrolling 100 subjects we can detect a difference of scores of at least 2.5 points. This enrollment will give us 80% power with an alpha of 0.05. Since the distribution of scores won't be normal, this enrollment target also includes a 15% increase to allow for a non-parametric distribution of results. Group (A) and group (S) will each have 50 children.