Introduction
The nasal cavity exists to warm, humidify, and sample air for olfaction as we inspire. The role of the paranasal sinuses is not as clear, though it is hypothesized that they exist, at least in part, to lighten the skull and provide a source of protection for the intracranial and orbital contents as a sort of “crash zone” in the case of head trauma. While these roles are important, many pathologies can also manifest within the nose and paranasal sinuses.
Many pathologies involving the nose and paranasal sinuses can be managed with minimally invasive surgery—termed endoscopic sinus or endoscopic skull base surgery ( Table 3.1 ). One of the most common pathologies within the paranasal sinuses is chronic rhinosinusitis, which is the presence of objective sinus inflammation for >12 weeks with associated symptoms such as mucopurulent drainage, nasal obstruction, and facial pain or pressure. Other common surgically managed pathologies include nasal airway obstruction and benign and malignant neoplasms. Many intracranial pathologies can involve the anterior and medial skull base, which can be managed through extended endoscopic endonasal approaches rather than external craniotomies.
| Anatomic abnormalities |
|
| Inflammatory/infectious |
|
| Benign sinonasal neoplasms |
|
| Malignancy sinonasal neoplasms |
|
| Intracranial/skull base pathology |
|
Surgical injuries, whether external or endoscopic, initiate an acute inflammatory reaction that manifests as pain. Postoperative pain is expected after most surgical procedures, and it is essential that surgeons understand and prepare patients for the pain that they will experience. Some people even go as far as to say that one of the primary goals of surgery is the appropriate management of the resultant pain.
Although endoscopic sinus and skull base surgeries are minimally invasive, it would be expected that they induce postoperative pain. Inadequate postoperative pain management adversely affects both the patient and the healthcare industry. Uncontrolled pain can result in surgical complications such as atelectasis from poor pulmonary toilet, thromboembolism from immobilization, and cardiovascular morbidity due to catecholamine release. These complications ultimately delay the patient’s return to normal functional status. , Studies have also demonstrated that inadequate pain management after surgery results in decreased patient quality of life, decreased satisfaction, increased hospital readmission rates, increased length of hospital stay, and increased healthcare costs. ,
A commonly cited source of surgical hesitation is the fear of severe or uncontrolled pain. In the realm of the opioid crisis, many patients are also concerned about opioid addiction and fear the use of opioids after surgery. By having a better understanding of the expected postoperative pain, surgeons can improve patient counseling, allowing patients to mentally prepare for their recovery and potentially improving postoperative outcomes.
Endoscopic sinus surgery
Pain after endoscopic sinus surgery
Endoscopic sinus surgery (ESS) is utilized to manage pathologies of the nose and paranasal sinuses. Currently, ESS is one of the most commonly performed procedures in the United States, with greater than 250,000 performed annually. Despite the prevalence of ESS, to date, there are no specialty-specific guidelines for the management of pain after surgery. Of those performed, approximately 3.7% result in readmission for pain. While 3.7% is low overall, this corresponds to nearly 10,000 patients per year who are readmitted for poorly controlled pain after ESS. There are also likely many more patients whose pain is poorly controlled but do not require readmission.
To appropriately counsel patients on pain expectations after ESS, it is important to first understand the painfulness of ESS. Many studies have been performed evaluating the severity of ESS-induced pain, all with similar results: ESS is not associated with severe pain. Utilizing a visual analog scale of 0–10, with 10 being the most severe pain, most studies have demonstrated that the peak of pain after ESS is approximately 2–4 on postoperative day 1 and rapidly declines over the course of the first week. , One study of 64 patients found that only nine patients (14.1%) reported pain greater than five out of 10 within the first week of ESS.
Many attempts have been made to identify features associated with increased pain after ESS. There is a general consensus that the severity of sinus disease, the presence or absence of nasal polyps, use of nasal packing, and extent of surgery do not significantly impact postoperative pain. , There are conflicting data regarding the impact of septoplasty on postoperative pain, with some studies demonstrating that the inclusion of a septoplasty at the time of ESS may increase pain, while other studies have not found a correlation. , , Although evaluations of pain after nonrhinologic surgery have demonstrated an impact of age, gender, and mental illness of postoperative pain, unpublished data from our group show that only the presence of anxiety adversely impacted the severity of postoperative pain (Smith Unpublished Data).
As a first step in mitigating pain after ESS, surgeons should counsel patients on the expectation of mild to moderately severe pain. Surgeons should also evaluate their patients preoperatively for anxiety and ensure that any comorbid anxiety is appropriately managed. Often patients with anxiety also require additional counseling regarding expectations of pain after surgery. By optimizing the surgeon–patient relationship and providing more extensive counseling preoperatively, patients may have more realistic expectations for pain after ESS, resulting in improved outcomes.
Preemptive pain control
Acute tissue injury modulates the central nervous system, ultimately sensitizing patients to pain. Preemptive pain control, the application of regional or systemic medications before the initial surgical injury, diminishes the central nervous system response, ultimately mitigating the severity of perceived postoperative pain. For ESS, many options have been proposed for preemptive pain control ( Table 3.2 ).
| Drug | Dose/concentration | Risks |
|---|---|---|
| Acetaminophen | 1000 mg PO | Nausea Headache Hepatotoxicity |
| Anticonvulsants | ||
| Gabapentin Pregabalin | 600–1200 mg PO 75–300 mg PO | Increased intraoperative bleeding Drowsiness Dizziness Nausea Anxiety Confusion Dry mouth |
| Glucocorticoids | ||
| Dexamethasone | 8–10 mg IV | Hyperglycemia Impaired wound healing |
| Alpha agonists | ||
| Dexmedetomidine Clonidine | 1 μg/kg IV bolus, 0.2 μg/kg/h infusion 2–5 μg/kg IV bolus, 0.3 μg/kg infusion | Sedation Dry mouth Nausea Vomiting Bradycardia Hypotension Loss of smell |
| Locoregional anesthetics | ||
| Lidocaine Bupivacaine Levobupivacaine | 1%–2% submucosal injection 0.25%–0.5% submucosal injection 0.5% submucosal injection | Dizziness Headache Blurred vision Twitching muscles Prolonged numbness |
Acetaminophen
Acetaminophen is a common, inexpensive analgesic. The exact mechanism of acetaminophen is unknown, though it is believed to work via the inhibition of cyclo-oxygenase (COX) enzymes with simultaneous modulation of the serotonergic and cannabinoid pathways. Overall, acetaminophen is well tolerated, though it has a known risk of hepatotoxicity, especially in those with a history of liver dysfunction.
Acetaminophen has been utilized for preemptive analgesia in nonrhinologic surgery, but there has only been limited research evaluating the role of preemptive acetaminophen for the prevention of ESS-induced pain. One study of otolaryngologic surgeries not limited to sinus surgery showed that the preoperative administration of acetaminophen resulted in a trend toward decreased pain after surgery, though the impact was not significant. Bjoja et al. evaluated the impact of a preoperative dose of 1000 mg oral acetaminophen administered preoperatively against 1000 mg of intravenous acetaminophen administered at the end of ESS and found no significant difference in postoperative pain, indicating that a single preemptive oral dose is likely equivalent to a postoperative intravenous dose.
Although the data are limited for ESS, acetaminophen has a long history of use in conjunction with surgery and is overall safe and well tolerated. Oral acetaminophen is significantly less expensive than parenteral acetaminophen, indicating that it is likely preferable to give a preoperative oral dose than to give an intravenous dose at the time of surgery. In patients in whom there is no contraindication, a preemptive dose of acetaminophen has little risk and the potential of significant benefit.
Gabapentinoids
The gabapentinoids gabapentin and its lipophilic analog pregabalin interact with neuron voltage-gated calcium channels, decreasing calcium influx and reducing neurotransmitter release. They were first introduced as antiepileptic drugs but have also been found to have antihyperalgesic and antiallodynic properties via the reduction of neuron hyperexcitability in injured tissue. The analgesic properties of gabapentinoids were first noted for neuropathic pain conditions such as diabetic neuropathy and postherpetic neuralgia. However, as gabapentinoids decrease neuronal excitability, there has been increased interest in their utilization for the prevention of central nervous system sensitization and postoperative pain.
Many studies outside of otolaryngology have evaluated the utility of a preemptive dose of gabapentin and pregabalin and have demonstrated their utility. One systematic review of 28 studies found that a preoperative dose of gabapentin significantly reduced postoperative analgesic requirements and pain for nonrhinologic surgeries. While those studies are promising, there is one potential drawback of preemptive gabapentinoids that may limit their utility for preemptive analgesia—gabapentinoids are known to inhibit platelet aggregation via the phospholipase C-inositol 1,4,5-triphosphate thromboxane A(2)-Ca(2+) pathway. Platelet inhibition could potentially increase bleeding during surgery. Although the studies for nonrhinologic surgery do not note significant changes in operative bleeding, small changes in hemostasis can significantly impact ESS. As ESS is reliant upon endoscopic visualization, poor hemostasis intraoperatively can result in limited visibility and thus increase the risk of complications and increase operative times.
To date, very few studies have evaluated the impact of preoperative gabapentinoids on postoperative pain and analgesic use for ESS. In a recent meta-analysis of sinus and nasal surgery, only three studies that evaluated the impact after ESS were identified. Those studies evaluated a range of preoperative gabapentin (600–1200 mg) and found that preemptive gabapentin significantly decreased analgesic requirements postoperative as well as lengthened the time until the first analgesic was required after ESS. Interestingly, despite the known side effects of nausea and vomiting, those that received gabapentin preoperatively had less postoperative nausea and vomiting. Although the data were limited, on meta-analysis, subjects in the ESS subgroup were noted to have increased operative blood loss after gabapentinoid administration than the septoplasty subgroup, but operative field visibility was not found to be significantly impaired.
Currently, there are no studies that have evaluated the use of pregabalin before ESS. However, pregabalin has been utilized before open septoplasty with promising results. Doses ranging from 75 to 300 mg have been administered, all of which significantly decreased pain within the first 24 h of surgery. Higher doses of pregabalin yielded more profound reductions in pain without apparent increases in adverse effects.
Preoperative gabapentinoids have promising results for the mitigation of postoperative pain. However, their utility for pain management may be limited by the potential impact on intraoperative hemostasis. Additional studies will need to be performed to determine the overall impact of preoperative gabapentinoids on ESS. If intraoperative hemostasis and visibility are not adversely impacted, the gabapentinoids may serve as a viable adjunct for preemptive analgesia.
Glucocorticoids
Glucocorticoids are potent antiinflammatory agents that have strong antiemetic properties and have been long utilized perioperatively for the prevention of postoperative nausea and vomiting. They are also known to improve vascular tone that provides a distinct advantage during ESS—decreased blood loss and improved visualization. When utilized long-term, glucocorticoids have the potential of causing significant morbidity—weight gain, hyperglycemia, insomnia, glaucoma, and osteonecrosis of the hip. However, a one-time preoperative dose of corticosteroid, most commonly dexamethasone, is generally safe and well tolerated.
Preemptive pain mitigation with glucocorticoids, most commonly dexamethasone, has been suggested for many nonrhinologic procedures based off the hypothesis that the potential antiinflammatory response can reduce central and peripheral inflammation and pain sensitization. There is abundant evidence in the nonrhinologic literature supporting this hypothesis. Some have even demonstrated that a single dose of dexamethasone at the beginning of a procedure can result in a greater than 10% reduction in opioid consumption within the first 24 h of surgery.
There are many benefits of preoperative glucocorticoids for ESS: decreased operative time, decreased blood loss, and improved visibility. While there are strong data supporting the preemptive use of glucocorticoids for the reduction of postoperative pain in other fields, there are minimal data for or against the role of glucocorticoids in the prevention of postoperative pain in ESS. Only one randomized controlled trial has been performed, which was unable to identify any significant impact of a preemptive dose of dexamethasone compared to placebo. Although the results of that study are not encouraging, a retrospective review of risk factors for opioid refills after ESS did note that a preoperative dose of glucocorticoid was associated with significantly decreased odds of requiring a refill of opioids. Although opioid refills are an indirect measure of pain, the decreased odds of requesting a refill do raise the question as to whether a preoperative dose of glucocorticoids may be beneficial for the prevention of pain after ESS.
Although glucocorticoids have not been shown to directly decrease pain after ESS, a preoperative dose of dexamethasone is generally safe and well tolerated. The significant impact on the reduction of postoperative nausea and vomiting as well as improved visualization during ESS supports the use of glucocorticoids at the time of ESS.
Alpha agonists
When performing endoscopic sinus surgery, hemostasis is of the utmost importance as excess bleeding decreases visibility increasing the operative risks and length of the procedure. Alpha-2 agonists, such as clonidine and dexmedetomidine, have a central nervous system effect, reducing neural activity through the inhibition of adenylyl cyclase. This results in vasoconstriction, which aids in intraoperative hemostasis, as well as sympatholytic, sedative, and allodynic changes, which may positively impact postoperative pain.
Dexmedetomidine is a highly selective alpha-2 agonist with hypotensive, sedative, and analgesic properties. It does so by modulating the alpha-2 receptors within the central nervous system while simultaneously inhibiting the release of inflammatory cytokines centrally and peripherally. The blockade of inflammatory mediators is thought to prevent central and peripheral sensitization, thus decreasing postoperative pain. A recent meta-analysis of 20 trials evaluating the effects of dexmedetomidine during nasal surgery demonstrated that intraoperative use of dexmedetomidine was associated with decreased postoperative pain and decreased intraoperative bleeding, suggesting that it would be a useful adjunct during ESS.
Clonidine is another alpha-2 agonist that has been theorized to be beneficial for the management of postoperative pain. On meta-analysis, eight studies evaluating the impact of clonidine on nasal surgery were identified. Overall, clonidine was found to lower intraoperative bleeding, but to a lesser extent than dexmedetomidine and was not associated with any decrease in postoperative pain. Thus, dexmedetomidine would be preferential if an alpha-2 agonist were to be utilized during ESS.
Unfortunately, while there have been many studies evaluating alpha-agonists, there is no consistent drug administration guideline, and many studies include only small cohorts of patients, limiting the generalizability of the results. Additionally, an adverse effect of smell loss has been observed in up to 15% has been noted. A known risk factor of ESS is olfactory loss, which can significantly impact patient quality of life. As such, anything that could increase the risk of olfactory loss, such as alpha-2 agonists, should be used with great caution in this patient population. However, if ESS is being performed on a patient with known long-standing anosmia, alpha-2 agonists may serve as a useful adjunct.
Locoregional anesthetics
The role of regional anesthesia has been well established throughout the surgical literature. Local anesthetics block nociceptive input at the time of tissue injury through the inhibition of voltage-gated sodium channels of neurons. When utilized, topical and regional anesthetics can act to inhibit both peripheral and central sensitization of pain, limiting the release of inflammatory cytokines, and ultimately limiting the severity of postoperative pain. The addition of epinephrine to the local anesthetic can potentiate these effects through vasoconstriction limiting drug clearance.
The sphenopalatine ganglion contains a large group of neurons that have somatosensory, parasympathetic, and sympathetic effects. The somatosensory component, via the trigeminal and facial nerves, supplies the majority of the sinonasal mucosa. Inhibition of these neurons has the potential to mitigate intraoperative nociceptive input, postoperative inflammatory responses, and the central processing of pain.
Located within the pterygopalatine fossa, the sphenopalatine ganglion can be accessed through multiple routes. Regional blockade can be obtained through direct infiltration of the ganglion either through a transoral or transnasal injection ( Fig. 3.1 ). Transoral injections utilize local anesthetic infiltrated through the greater palatine foramen. An alternative option for the sphenopalatine ganglion regional block is the transnasal injection. To perform the transnasal injection, the surgeon must visualize and inject an anesthetic into the region of the sphenopalatine foramen adjacent to the lateral attachment of the middle turbinate under endoscopic guidance. Both injections of local anesthetic, whether applied transorally or transnasally, can be technically challenging and have a steep learning curve. Additionally, injection of the sphenopalatine ganglion is not without risk. Given the local connections to the internal carotid plexus, injection into the pterygopalatine fossa can lead to systemic absorption of local anesthetic. This can result in seizures from lidocaine toxicity or cardiovascular compromise if the local anesthetic is mixed with epinephrine.
