Suprazygomatic Maxillary Nerve Blocks for pediatric T&A
Myron Yaster MD, Francis Veyckemans MD, and Karen Boretsky MD
Adenotonsillectomy is amongst the most common and painful procedures performed in pediatrics. In today’s PAAD, Lin et al.1 wondered if the “suprazygomatic maxillary nerve block (also known as maxillary nerve, pterygopalatine, and infratemporal fossa block) could be administered to block the maxillary nerves under ultrasound guidance as a regional anesthesia technique and opioid-sparing adjuvant for managing postoperative pain after pediatric intracapsular adenotonsillectomy.”1 This technique selectively anesthetizes the posterior pharynx while preserving vital protective airway reflexes, such as coughing and swallowing, by sparing the glossopharyngeal nerve. Previous publications on the use of the glossopharyngeal nerve for post-tonsillectomy pain have indeed shown instances of upper airway obstruction.2
For those of you unfamiliar with this block and how ultrasound guidance can be useful in performing it, I am also including a video guide from the Society for Pediatric Pain Medicine’s incredible video pearl collection and some wonderful images from the NYSORA collection. Myron Yaster MD
Original article
Lin C, Abboud S, Zoghbi V, Kasimova K, Thein J, Meister KD, Sidell DR, Balakrishnan K, Tsui BCH. Suprazygomatic Maxillary Nerve Blocks and Opioid Requirements in Pediatric Adenotonsillectomy: A Randomized Clinical Trial. JAMA Otolaryngol Head Neck Surg. 2024 May 23:e241011. doi: 10.1001/jamaoto.2024.1011. Epub ahead of print. PMID: 38780948; PMCID: PMC11117150.
Video pearl from the Society for Pediatric Pain Medicine
Nerve blocks of the face rom NYSORA
https://www.nysora.com/techniques/head-and-neck-blocks/nerve-blocks-face/
Adenotonsillectomy is amongst the most common and painful procedures performed in children and opioid-based analgesia has historically been the norm. Opioid-sparing and opioid-free analgesic techniques are currently being investigated to avoid the many opioid-related complications including PONV, respiratory depression and chronic opioid abuse.3,4 Regional anesthesia has been very effective in many surgeries in decreasing opioid requirements. The adenotonsillar tissues receive innervation predominantly from the lesser palatine branch of the maxillary nerve, as well as the glossopharyngeal nerve, creating a complex neural network (figure 1). Lin et al. wondered if a suprazygomatic maxillary nerve block (also known as maxillary nerve, pterygopalatine, and infratemporal fossa block), based on the method described by Mesnil et al5 (figure 2) would effectively provide opioid sparing perioperative analgesia. Some encouraging preliminary data have already been published in adults6 and children.7,8
In this prospective, (mostly) blinded, randomized controlled trial, patients were divided into 2 groups. The experimental group received the suprazygomatic nerve block (ropivacaine 0.5% , 1 mg/kg) under ultrasound guidance after induction of anesthesia while the control group did not. Other than the nerve block, both groups had identical intraoperative analgesia which included 2 mcg/kg fentanyl. “The anesthesiologists performing the blocks were part of a highly experienced team that routinely administers and places these blocks as part of our enhanced recovery protocol for cleft palate repairs and other procedures involving pediatric patients at our institution.”1 Residents and attending surgeons performed the intracapsular adenotonsillectomies. “Opioid consumption, FLACC (Face, Legs, Activity, Cry, Consolability) scores, and rates of opioid-free post anesthesia care unit (PACU) stay were the primary outcomes of interest Secondary outcomes were duration of stay in hospital care areas, duration and incidence of adverse effects, including nausea, vomiting, block-related complications, and emergency delirium.”1
The results were rather modest. “The mean (SD) opioid morphine equivalent consumption during PACU stay was 0.15 (0.14) mg/kg for the 27 patients in the control group compared with 0.07 (0.11) mg/kg for the 26 patients in the block group (mean difference, 0.08; 95% CI, 0.01-0.15). The block group had a higher incidence of opioid-free PACU stays (n = 7 patients; 58%) compared with the control group (n = 15 patients; 26%) (mean difference, 32%; 95% CI, 5%-53%). The overall occurrence of adverse events was similar in the 2 groups, with no reported nerve block-related complication. There was no difference in pain scores in the 3 postoperative days following discharge. Patients in the block group spent a mean of 82.4 minutes in the operating room compared with 65.5 minutes in the control group (mean difference, 16.8; 95% CI, 6.3 to 27.3). This almost 17 minutes of extra OR time was attributed to block performance time with blocks being performed by the most experienced anesthesiologists in the practice. Finally, intracapsular tonsillectomy is known to be associated with reduced pain compared to extracapsular tonsillectomy potentially restricting the applicability of the study.
Are these modest results worth the extra OR time required to perform the blocks? We are not sure. Can opioid-sparing goals be achieved without the maxillary nerve block? Franz et al achieved 95% intraoperative opioid-free anesthesia and 92% opioid-free PACU analgesia without regional anesthesia. 8
The dosing in this study is below the accepted maximum of 2.5 mg/kg but is higher than many common doses for the maxillary block. In our experience (FV), ropivacaïne 0.2% 0.15 ml/kg works well. While the block can be performed more quickly using landmarks, the use of ultrasound likely improves the success and reliability.
What do you think? Send your thoughts and comments to Myron who will post in a Friday reader response.
References
1. Lin C, Abboud S, Zoghbi V, et al. Suprazygomatic Maxillary Nerve Blocks and Opioid Requirements in Pediatric Adenotonsillectomy: A Randomized Clinical Trial. JAMA Otolaryngol Head Neck Surg 2024 (In eng). DOI: 10.1001/jamaoto.2024.1011.
2. Bean-Lijewski JD. Glossopharyngeal nerve block for pain relief after pediatric tonsillectomy: retrospective analysis and two cases of life-threatening upper airway obstruction from an interrupted trial. Anesthesia and analgesia 1997;84(6):1232-8. (In eng). DOI: 10.1097/00000539-199706000-00011.
3. Amin SN, Thompson T, Wang X, et al. Reducing Pediatric Posttonsillectomy Opioid Prescribing: A Quality Improvement Initiative. Otolaryngology--head and neck surgery : official journal of American Academy of Otolaryngology-Head and Neck Surgery 2024;170(2):610-617. (In eng). DOI: 10.1002/ohn.534.
4. Martin LD, Franz AM, Rampersad SE, et al. Outcomes for 41 260 pediatric surgical patients with opioid-free anesthesia: One center's experience. Pediatric Anesthesia 2023;33(9):699-709. DOI: https://doi.org/10.1111/pan.14705.
5. Mesnil M, Dadure C, Captier G, et al. A new approach for peri-operative analgesia of cleft palate repair in infants: the bilateral suprazygomatic maxillary nerve block. Paediatric anaesthesia 2010;20(4):343-9. (In eng). DOI: 10.1111/j.1460-9592.2010.03262.x.
6. Smith CR, Helander E, Chheda NN. Trigeminal Nerve Blockade in the Pterygopalatine Fossa for the Management of Postoperative Pain in Three Adults Undergoing Tonsillectomy: A Proof-of-Concept Report. Pain medicine (Malden, Mass) 2020;21(10):2441-2446. (In eng). DOI: 10.1093/pm/pnaa062.
7. Smith L, Balakrishnan K, Pan S, Tsui BCH. Suprazygomatic maxillary (SZM) nerve blocks for perioperative pain control in pediatric tonsillectomy and adenoidectomy. Journal of clinical anesthesia 2021;71:110240. (In eng). DOI: 10.1016/j.jclinane.2021.110240.
8. Tsui BCH, Pan S, Smith L, Lin C, Balakrishnan K. Opioid-Free Tonsillectomy With and Without Adenoidectomy: The Role of Regional Anesthesia in the "New Era". Anesthesia and analgesia 2021;133(1):e7-e9. (In eng). DOI: 10.1213/ane.0000000000005567.