Block of the Sphenopalatine Nerve Ganglion for Postoperative Analgesia

Block of the Sphenopalatine Nerve Ganglion for Postoperative Analgesia in Transsphenoidal Approaches: a Prospective, Randomized and Double-blind Study

Transsphenoidal surgery is considered safe and effective and is currently the procedure of choice for the removal of intrasellar lesions. Direct transnasal access to the sphenoid sinus, without the need for detachment of the nasal septum, provides less postoperative morbidity compared to traditional methods. Sphenopalatine ganglion block is known for its efficacy in otorhinolaryngological surgeries in which the sinuses are approached by transnasal endoscopy, as an important part of postoperative analgesia. However, in a neurosurgical environment, specifically in the treatment of tumors of the sella turcica, the use of the blockade of the referred ganglion to produce postoperative analgesia has been used in a scarce way in the literature. The primary objective of the study is to verify whether blocking the sphenopalatine nerve ganglion in the nasopharynx posterior wall provides better postoperative pain control in surgeries with nasal access for transsphenoidal approach, compared to the placebo group. As secondary objectives, the investigators will observe the consumption of opioids in the intraoperative period, in addition to the incidence of nausea, vomiting and postoperative headache also within 24 hours. Forty patients with physical status P1, P2 or P3 will be prospectively analyzed by the American Society of Anesthesiology (ASA) to undergo microsurgery for tumors with a sellar and / or suprasellar location, with transsphenoidal access, in patients with an age range between 18 and 64 years old, including men and women.

Transsphenoidal surgery is considered safe and effective and is currently the procedure of choice for the removal of intrasellar lesions. Direct transnasal access to the sphenoid sinus, without the need for detachment of the nasal septum, provides less postoperative morbidity compared to traditional methods. Sphenopalatine ganglion block is known for its efficacy in otorhinolaryngological surgeries in which the sinuses are approached by transnasal endoscopy, as an important part of postoperative analgesia. However, in a neurosurgical environment, specifically in the treatment of tumors of the sella turcica, the use of the blockade of the referred ganglion to produce postoperative analgesia has been used in a scarce way in the literature. The primary objective of the study is to verify whether blocking the sphenopalatine nerve ganglion in the nasopharynx posterior wall provides better postoperative pain control in surgeries with nasal access for transsphenoidal approach, compared to the placebo group. As secondary objectives, the investigators will observe the consumption of opioids in the intraoperative period, in addition to the incidence of nausea, vomiting and postoperative headache also within 24 hours. Forty patients with physical status P1, P2 or P3 will be prospectively analyzed by the American Society of Anesthesiology (ASA) to undergo microsurgery for tumors with a sellar and / or suprasellar location, with transsphenoidal access, in patients with an age range between 18 and 64 years old, including men and women. As for the surgical technique, both the use of the microscope and the endoscope will be considered. They will be randomly allocated to a placebo group (group P; 0.9% saline, n = 20) and a test group (group R; ropivacaine 1%, n = 20).

The block of the sphenopalatine ganglion will be performed bilaterally through a cotton bud soaked with the anesthetic solution ropivacaine, at a concentration of 1%, advancing it through the nasal cavities towards the posterior nasopharynx wall. A slight resistance in the progression of the cottonoid indicates its contact with the mucosa of the posterior pharyngeal wall. The cottonoid will remain in this position for 20 minutes, so that there is absorption of the anesthetic solution through the mucosa up to the sphenopalatine ganglion, which, in general, is found anatomically around 3 millimeters in depth from the surface. After the established time, the cotton buds are removed.

The block of the sphenopalatine ganglion will be performed bilaterally through a cotton bud soaked with saline solution, in a concentration of 0.9%, advancing it through the nasal cavities towards the posterior wall of the nasopharynx. A slight resistance in the progression of the cottonoid indicates its contact with the mucosa of the posterior pharyngeal wall. The cottonoid will remain in this position for 20 minutes, so that the solution is absorbed by the mucosa up to the sphenopalatine ganglion, which, in general, is anatomically three millimeters deep from the surface. After the established time, the cotton buds are removed.

The block of the sphenopalatine ganglion will be performed bilaterally, using a cotton bud soaked with 1% ropivacaine, placed in the mucosa of the posterior wall of the nasal cavity, through both nostrils. Once placed in the proper position, the swab will remain for about 20 minutes to absorb the local anesthetic from the mucosa.

To verify whether blocking the sphenopalatine nerve ganglion in the posterior nasopharynx wall provides change in postoperative pain control, assessed using the visual analogue pain scale, in surgeries with nasal access for transsphenoidal approach, compared to the placebo group.

To verify whether blocking the sphenopalatine nerve ganglion in the posterior nasopharynx wall provides change in postoperative pain control, assessed using the visual analogue pain scale, in surgeries with nasal access for transsphenoidal approach, compared to the placebo group.

To verify whether blocking the sphenopalatine nerve ganglion in the posterior nasopharynx wall provides change in postoperative pain control, assessed using the visual analogue pain scale, in surgeries with nasal access for transsphenoidal approach, compared to the placebo group.

To verify whether blocking the sphenopalatine nerve ganglion in the posterior nasopharynx wall provides change in postoperative pain control, assessed using the visual analogue pain scale, in surgeries with nasal access for transsphenoidal approach, compared to the placebo group.

To verify whether blocking the sphenopalatine nerve ganglion in the posterior nasopharynx wall provides change in postoperative pain control, assessed using the visual analogue pain scale, in surgeries with nasal access for transsphenoidal approach, compared to the placebo group.

Assess the number of rescue doses with opioids in pos operative period for for adequate analgesia (it is understood as insufficient analgesia classification on the visual analog scale of pain greater than or equal to 3)

Assess the number of rescue doses with opioids in pos operative period for for adequate analgesia (it is understood as insufficient analgesia classification on the visual analog scale of pain greater than or equal to 3)

Assess the number of rescue doses with opioids in pos operative period for for adequate analgesia (it is understood as insufficient analgesia classification on the visual analog scale of pain greater than or equal to 3)

Assess the number of rescue doses with opioids in pos operative period for for adequate analgesia (it is understood as insufficient analgesia classification on the visual analog scale of pain greater than or equal to 3)

Assess the number of rescue doses with opioids in pos operative period for for adequate analgesia (it is understood as insufficient analgesia classification on the visual analog scale of pain greater than or equal to 3)

Inclusion Criteria: Both genders; Age between 18 and 64 years; Physical status according to the American Society of Anesthesiologists (ASA) I, II and III Saddle or suprasellar tumors with transsphenoidal access; Exclusion Criteria: Participation in another study in the last month; Patients with a history of chronic pain; Previous surgeries with a transsphenoidal approach; Known hypersensitivity to ropivacaine; Patient's refusal;

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Cho DY, Drover DR, Nekhendzy V, Butwick AJ, Collins J, Hwang PH. The effectiveness of preemptive sphenopalatine ganglion block on postoperative pain and functional outcomes after functional endoscopic sinus surgery. Int Forum Allergy Rhinol. 2011 May-Jun;1(3):212-8. doi: 10.1002/alr.20040. Epub 2011 Apr 13.

Bilateral sphenopalatine ganglion block as adjuvant to general anaesthesia during endoscopic trans-nasal resection of pituitary adenoma