Anesthesia for Nasal Surgery, Pre- and Postoperative Care
Summary
Anesthetic techniques and pre- and postoperative care for patients undergoing nasal surgery are critical elements in determining the success of the operation. The nasal surgeon must carefully consider the wide range of anesthetic techniques and individualize the pre- and postoperative care for each patient to optimize the outcome.
Introduction
Successful results in endoscopic sinus surgery (ESS) depend not only on meticulous surgical technique, but also on careful attention to preoperative planning, intraoperative anesthetic techniques, and postoperative care. Preoperative planning includes a bleeding risk assessment, comprehensive evaluation of preoperative imaging, and steps to reduce the inflammatory and infectious processes in the sinonasal cavity. During surgery, various anesthetic techniques are used to decrease intraoperative blood loss and maintain a clear surgical field. The goals of postoperative care are maximizing wound healing, restoring mucociliary clearance, maintaining ostia patency, preventing scar formation, and avoiding rhinosinusitis. Medical management and débridements are important for successful management of the postoperative sinonasal patient.
Preoperative Planning in Sinus Surgery
Bleeding is one of the most common causes of incomplete surgical management, intraoperative complications, and postoperative scarring after ESS.1 Consequently, a preoperative bleeding risk assessment should be performed prior to sinonasal surgery. A complete medical history that includes assessment of medical conditions, current medications, alternative therapies, and a specific bleeding history, must be ascertained (Table 30.1).
Note
Inquiring about medications and supplements that increase the risk of bleeding is important prior to proceeding with surgery.
Common inherited and acquired coagulopathies should also be ruled out prior to surgical intervention. Common inherited anomalies include von Willebrand disease and hemophilia. Acquired coagulopathies encompass medical conditions, such as liver failure, and vitamin deficiencies, as well as ingestion of antiplatelet drugs, anticoagulants, and dietary supplements. Appropriate screening questions must be ascertained to identify patients with likely bleeding disorders (Table 30.2). In patients with a suggestive bleeding history, further tests may be ordered.
Von Willebrand disease is an autosomal inherited condition affecting 1 to 2% of the population, where a defect in the von Willebrand factor (vWF) compromises the ability of platelets to adhere together and inability to transport factor VIII. Patients may present with mucosal bleeding, petechiae, or purpura. Most a? icted patients may be treated preoperatively with desmopressin administered at 0.3 µg/kg over 20 to 30 minutes, which releases vWF and factor VIII from storage sites.
Hemophilia A and B are X-linked recessive diseases that lack factors VIII and IX, respectively. Patients may present with hematomas and hemarthrosis. Hemophilia A can be treated with desmopressin in mild cases, and factor VIII in moderate to severe cases. Supplementation with factor IX is the treatment for hemophilia B.2
Note
A thorough preoperative work-up that includes eliciting a thorough bleeding history is critical for the success in endoscopic sinonasal surgery.
Although there is a paucity of studies examining ESS in patients with common inherited coagulopathies, there are some data on patients with acquired coagulopathies undergoing sinus surgery. One such prospective series examined ESS for medically refractory rhinosinusitis in patients with chronic liver failure who were awaiting transplantation.3 These patients experienced a high degree of blood loss (average 495 mL), with, not surprisingly, the most severe bleeding in patients with severe liver failure, low albumin, and significant sinus disease. The authors concluded that despite the use of fresh frozen plasma, platelets, albumin, and other blood products, significant perioperative blood loss may be unavoidable.
The routine use of coagulation studies in patients without a specific bleeding history has not been shown to have any benefit in predicting the risk of intraoperative bleeding.4 Laboratory evaluation, however, should be pursued in patients with a history suggestive of bleeding problems. These tests include a platelet count, prothrombin time (PT), activated partial thromboplastin (aPTT), and fibrinogen.5 Anticoagulant and antiplatelet medications must be stopped at least 1 week prior to surgery when possible. Patients who have a strong indication for continuous anticoagulation may be bridged with medications such as heparin, low molecular weight heparin, or nonsteroidal antiinflammatory drugs (NSAIDs).6 Alternative therapies, dietary supplements, and herbal medications must be avoided for at least 1, but preferably 3, weeks prior to surgery.2
Steroids (oral and topical) and antibiotics are commonly used in the perioperative period to reduce paranasal sinus inflammation and thereby improve intraoperative conditions and postoperative surgical outcomes (Table 30.3).
Oral steroids have been postulated to reduce intraoperative bleeding secondary to the vasoconstrictive effects of adrenaline on smooth muscle. A significant improvement in the operative field with preoperative oral steroids (30 mg daily for 5 days) compared with placebo was demonstrated in two matched groups of 18 patients with nasal polyposis undergoing ESS. These groups were matched for age, body mass index, general health status, incidence of allergy, bronchial asthma, aspirin triad, and stage of disease.7 In a randomized, controlled trial, preoperative treatment with topical corticosteroids (mometasone furoate) for 1 month was shown to statistically reduce bleeding (P = .025), decrease operative time (P = .009), and improve the quality of the surgical field in patients with and without nasal polyps during ESS.1 Perioperative antibiotics are also often used to reduce the bacterial load and inflammation and optimize the intraoperative surgical field and decrease postoperative scarring. The evidence for using preoperative antibiotics to improve operative conditions and postoperative healing is largely empiric. However, one recent prospective, randomized, double-blind, placebo-controlled study in 75 patients (40 in the antibiotic-treated group and 35 in the placebo group) demonstrated reduced nasal obstruction and drainage in the postoperative period after treatment with amoxicillin/clavulanate for 2 weeks.1 Barring any contraindications, preoperative antibiotics and steroids are begun 7 to 14 days prior to endoscopic sinonasal surgery in most patients with chronic rhinosinusitis (CRS). Patients with nasal polyps are started on larger doses of preoperative steroids to reduce bleeding and improve the surgical field.
Note
Decreasing sinonasal inflammation through the use of preoperative steroids can help improve the operative field for the surgeon.
In some instances, patients with specific sinonasal conditions may be more likely to have increased predisposition to inflamed sinonasal lining. Patients with aspirin-exacerbated respiratory disease (AERD), granulomatous diseases, allergic fungal rhinosinusitis (AFRS), cystic fibrosis (CF), and vasculitis disorders have all been noted to have high levels of sinonasal inflammation. In these cases, specific preoperative measures should be considered to maximize the intra- and postoperative results. Barring any medical contraindications, pre- and postoperative topical and oral steroids are strongly considered for patients with these disorders. Preoperative use of antileukotriene inhibitors and postoperative treatments for aspirin desensitization are often considered for patients with AERD. Patients with CF often undergo a pulmonary “tune-up” to reduce postoperative complications. Immunotherapy and the extended use of oral corticosteroids may improve postoperative results in patients with AFRS. In all of these cases, close coordination with the patient′s managing physician is imperative.
Preoperative planning for sinonasal surgery includes a bleeding risk assessment, comprehensive evaluation of preoperative imaging, and measures to reduce the inflammatory and infectious processes in the sinonasal cavity. Common inherited and acquired coagulopathies must be ruled out prior to surgical intervention. Careful study of preoperative imaging is imperative for a successful result and avoidance of intraoperative complications.
General Anesthesia in Sinus Surgery
The type of anesthesia and techniques used during ESS can significantly influence the operative field.
Patient Positioning
Patient positioning in the reverse Trendelenburg position, 5 to 15 degrees from parallel, in liver resections has been shown to reduce central venous pressure from 9.2 to 1.7 mm Hg.8 This position is also important to reduce the risk of inadvertent injury to the fovea ethmoidalis during surgery. In addition, studies have shown a decrease in blood flow to sinonasal structures and a decrease in blood loss with ~10 to 20 degrees of reverse Trendelenburg compared with the supine position.9,10
Anesthetic Techniques
Several studies have been performed looking at the effect of various anesthetic agents on bleeding during ESS. A large number of articles have examined the difference in the surgical field when using intravenous (IV) propofol versus an inhalational agent. One such study examined the effects of total intravenous anesthesia (TIVA) (propofol, remifentanil) versus inhalational anesthesia (sevoflurane, fentanyl) on blood pressure (BP), heart rate (HR), and surgical field (Boezaart scale). The authors found that the surgical field was improved with TIVA, and the improved field correlated independently with lower BP and HR.11 The majority of articles concluded that the use of IV propofol in ESS improves the surgical field and/or results in decreased blood loss.12 However, a minority of studies did not confirm this result. Beule et al13 examined the differences on the HR, blood loss, blood loss/min, platelet function, and surgical field (visual analogue scale [VAS]) when using TIVA (propofol, fentanyl) versus inhalational anesthesia (sevoflurane, fentanyl). The authors found no significant difference in HR, blood loss, blood loss/min, and surgical field. The results of these studies are summarized in Table 30.4. The platelet function was impaired in both groups but was worse in the TIVA group.13 Platelet function has been noted to be impaired with inhalational agents sevoflurane and nitrous oxide, as well as IVs agents such as propofol. Other inhalational agents, such as isoflurane and desflurane, have not been shown to alter platelet function.14
The effects of hypercapnia on the surgical field and blood loss have also been studied. Retention of carbon dioxide (CO2) causes smooth muscle relaxation and vasodilation, resulting in a potential increase in blood loss. Nekhendzy et al15 found no difference in the surgical field and blood loss in patients undergoing ESS in hyper-, hypo-, or normocapnic groups.
Local Anesthesia in Sinus Surgery
Advantages and Disadvantages
There are advantages and disadvantages to performing ESS under local anesthesia. Three main advantages are:
Local anesthesia is not effective at the periorbit or the dura. Should the lamina papyracea or the skull base be reached, the patient will usually warn the surgeon by complaining of pain. Also, manipulation near the optic nerve may produce visual stimulus.
The operating field is often dryer as excess blood loss associated with the positive pressure and vasodilation of general anesthesia is avoided. The anesthetic agent itself causes vasoconstriction with the same effect.
In some cases, surgery can be performed in patients deemed unfit for general anesthesia. This is an advantage especially to patients with severe pulmonary disease where the sinuses are often involved.
Disadvantages of performing ESS under local anesthesia are
The patient is awake (although possibly sedated). Therefore, the surgeon has to divide his or her attention between the state of the patient and the actual surgery. Adequate communication between the surgeon and patient must be possible to monitor patient progress.
Achieving adequate anesthesia in certain areas (frontal recess, sphenoid) can be difficult. Also, operating time is limited to the duration of the anesthetic. Repeated administrations are usually not effective.
Excessive blood loss may cause gagging, especially if the swallowing reflex has been suppressed by the local anesthetic or sedatives, and will be troublesome to the patient and the surgeon.
In cases of active infection or massive polyposis local anesthetics and vasoconstrictors are less effective, and the anesthetic effect may be insufficient to perform surgery.
In patients with severe health problems, the advantages of the high level of monitoring during general anesthesia may outweigh the disadvantage of the extra burden to the system. Also, in patients with cardiovascular disease certain local anesthetics and/or vasoconstrictors such as cocaine may be contraindicated. In these patients it is advisable that the treating physician or anesthesiologist should be actively involved in the decision to operate under general or local anesthesia.
Relative contraindications to performing ESS under local anesthesia therefore include
Possible communication barriers (excessive anxiety, language barrier, children)
Extensive or prolonged surgery (> 90 min)
Active infection or massive polyposis
Very poor health status/cardiovascular disease
Although a teaching situation is more demanding under local anesthesia, the experience of the authors (Sjögren and Brenkman) is that it does not have to be a contraindication especially for minor procedures.
It should be noted that, although the advantages of operating under local anesthesia as described above are widely acknowledged,16–18 they are mostly experience based. The scientific proof in support of this mode of operating is thin, consisting of just a few studies. Gittelman et al19 compared blood loss and the overall complication rate in 232 patients undergoing ethmoidectomy (149 under local anesthesia with sedation and 83 under general anesthesia). Average blood loss in the local anesthesia group was 23 mL per side versus 58 mL in the general anesthesia group. Surprisingly, the overall complication rate was higher in the local group (8.7% vs 2.4%), with severe bleeding occurring in four patients despite lower average blood loss during surgery. However, this is a descriptive, retrospective report, and no statistical analysis or baseline comparison of the groups was performed.19 In another patient series, Lee et al20 reported only 1.4% complications (0.5% major) in 554 patients undergoing ESS under local anesthesia with sedation over the course of 5 years.
Several authors mentioned the use of some form of sedation under local anesthesia, usually in the form of oral, intramuscular, or IV administration of benzodiazepines, such as midazolam,20 or an opiate such as morphine20 or pethidine (meperidine hydrochloride).21 In the clinic of one of the authors (Sjögren), 7.5 to 15 mg of midazolam is administered orally in anxious patients, although in smaller interventions, frequently no premedication is given at all. Obviously, depending on the substance and dosage, the depth of the sedation will vary and may require anesthesiologic monitoring. If using premedication, additional attention must be paid to the state of the patient by the surgeon, as active responses and reflexes of the patient may become inhibited.
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
