Suprazygomatic Maxillary Nerve Block in Cleft Palate Outcomes

Suprazygomatic Maxillary Nerve Block in Cleft Palate Outcomes: Can we Minimize Analgesic and Opioid Use?

Increased pain after cleft palate surgery is the leading cause of increased hospital length of stay, delayed oral intake, readmission, and respiratory compromise. The goal is to improve all outcomes by identifying the most effective evidenced-based method of intra-operative pain control.

Cleft palate repair is associated with significant perioperative pain that may require increased depth of anesthesia intraoperatively and can interfere with oral intake and accentuate breathing difficulties postoperatively, resulting in increased length of hospital stay. Optimizing pain control in the perioperative period is essential to best practice for cleft palate repair. Infiltration of the palate with local anesthetic has long been the established mechanism for pain control to minimize intraoperative anesthetic requirement and postoperative opioid use. Suprazygomatic maxillary nerve block (SMB) administered immediately prior to cleft palate repair by anesthesiologists with fellowship training in regional anesthesia is an emerging technique for local anesthetic infiltration. The latter technique is thought to provide superior pain control due to its precise and targeted action on the nerves that innervate the palate, and because it is felt that duration of action may also be prolonged due to specific infiltration around these nerves as opposed to generalized infiltration in the palatal soft tissues. The goal of our study is to evaluate outcomes following the two routes for anesthetic infiltration during cleft palate repair. If either technique is found to be more effective or of greater duration, this can have direct impact in decreasing the need for perioperative opioid use, decreasing hospital length of stay, and less potential for airway suppression from excessive use of postoperative analgesics.

Patients randomized to this arm will receive an ultrasound-guided bilateral suprazygomatic maxillary nerve block using 0.15 ml/kg of 0.2% ropivacaine per side, for a total of 0.3 ml/kg immediately after induction of general anesthesia and prior to incision. Participants will also receive local infiltration of the palate with an equivalent injection volume of 0.9% saline with 1:400,000 epinephrine at 2 ml/kg. Pediatric anesthesiologists with fellowship training in regional anesthesia will perform the nerve block. Local anesthetic infiltration will be performed by one of four board-certified pediatric plastic and craniofacial surgeons during repair of the palate. Patients, parents, surgeons, and the anesthesiologist will not be blinded to the specific intervention group due to the nature of the procedures involved. Nurses and the two key personnel responsible for data collection and analysis will be blinded throughout the entirety of the study.

Patients randomized to this arm will receive local infiltration of the palate using 0.125% bupivacaine + 1:400,000 epinephrine at a dose of 2 ml/kg intraoperatively. Local anesthetic infiltration will be performed by one of four board-certified pediatric plastic and craniofacial surgeons during repair of the palate. Patients, parents, surgeons, and the anesthesiologist will not be blinded to the specific intervention group due to the nature of the procedures involved. Nurses and the two key personnel responsible for data collection and analysis will be blinded throughout the entirety of the study.

The maxillary nerve, V2, is purely a sensory branch of the trigeminal nerve. V2 exits the skull through the foramen rotundum and courses through the pterygopalatine fossa, a small pyramid-shaped depression located posterior to the maxilla. As the maxillary nerve exits the pterygopalatine fossa, it divides into numerous branches that supply sensation to the posterior nasal cavity, palate, sinuses, and maxilla. It is within the pterygopalatine fossa that the maxillary nerve is targeted and anesthetized during the block. With the patient in the supine position after nasotracheal intubation, a needle is inserted perpendicularly between the upper border of the zygomatic arch and posterior orbital rim until it reaches the greater wing of the sphenoid, where the needle is then retracted by a few millimeters and redirected toward the nasolabial fold until it hits the pterygopalatine fossa.

Local anesthetic infiltration of the palate during cleft palate repair is universally practiced. The benefits of local anesthetic infiltration are twofold: to provide anesthesia to the terminal branches of the nasopalatine and greater palatine nerves that are in the immediate area of the injection sites and to achieve hemostasis during closure when the medication is mixed with epinephrine. To administer local anesthetic infiltration of the palate, a 25 gauge needle is inserted next to the incision into the soft tissue. The tissue is first aspirated to determine safety of injection at that site. The medication is then injected parallel to the incision on both sides.

Evaluation of ultrasound-guided bilateral suprazygomatic maxillary nerve block on postoperative pain scores.

The primary outcome for this aim will be pain scores, as determined by the Face, Legs, Activity, Crying, and Consolability scale. Minimum value is 0, maximum value is 10. Higher scores indicate more pain and therefore a worse outcome.

Evaluation of ultrasound-guided bilateral suprazygomatic maxillary nerve block on perioperative analgesia requirements.

The primary outcome for this aim will be perioperative opioid consumption reported in morphine milligram equivalents.

A blinded researcher will perform a thorough review of patient data to determine the duration of hospital stay (hours).

Evaluation of ultrasound-guided bilateral suprazygomatic maxillary nerve block on time to oral intake.

A blinded researcher will perform a thorough review of patient data to determine the time to oral intake (minutes).

Evaluation of ultrasound-guided bilateral suprazygomatic maxillary nerve block on total amount of fluids consumed.

A blinded researcher will perform a thorough review of patient data to determine the total amount of fluids consumed (ounces).

Inclusion Criteria: All patients undergoing primary cleft palate repair at Ann & Robert H. Lurie Children's Hospital of Chicago during the enrollment period. The typical child at the time of cleft palate repair is age 11 to 12 months. Exclusion Criteria: Children with a known allergy to local anesthesia (i.e., ropivacaine or bupivacaine). Children with prior surgical repair of the palate.