What the Anesthesiologist Should Know before the Operative Procedure

Otological procedures, by nature, require the patient to be positioned in a way that the anesthesia care team may have limited access to the airway intraoperatively. Many procedures may be performed under local anesthesia with sedation; however, those that require prolonged drilling into bone may be more amenable to general anesthesia. Additionally, many of the patients suffer from loss of hearing, making intraoperative communication difficult in the awake patient. Preoperatively, history and consent can be facilitated by use of a sign language interpreter, computer screen, or writing tablet for patients and providers who are not proficient with sign language. Procedures of the ear can be highly emetogenic, and middle ear procedures can result in postoperative dizziness, vertigo, nausea, vomiting, and nystagmus.

Postoperative Valsalva as seen with vomiting can adversely affect the results of the surgical procedure. Other concerns include the effect of nitrous oxide on the surgery and facial nerve integrity.

Local anesthetic used by the surgeon frequently contains epinephrine (1:100,000 concentration) to facilitate vasoconstriction and bloodless surgical field. The epinephrine may be inadvertently placed intravascularly or systemically absorbed and can result in hypertension, tachycardia, or malignant dysrhythmia.

1. What is the urgency of the surgery?

What is the risk of delay in order to obtain additional preoperative information?

Emergent: Infection or abscess in the mastoid sinus or adjacent to the brain. Delay in treatment may result in meningitis, brain abscess, and rapidly ensuing death. Acceptable to delay for STAT laboratory values, STAT CXR, and ECG if they will impact care.

Urgent: Foreign body in the ear canal, infection of implantable hearing aid, and mastoiditis. Can delay for routine testing as warranted by the patient’s history.

Elective: PE tube placement, cochlear implant device placement, tympanoplasty with or without ossicular chain reconstruction, stapedotomy, stapedectomy, and BAHA (bone-anchored hearing aid). Preoperative discussion with surgeon to include desired level of consciousness of the patient (i.e., does the patient need to respond to audible cues for the surgeon to assess functional results?), desirability of muscle relaxation (do not use if neuromonitoring for facial nerve integrity) in patients who are intubated, duration of procedure, and potential for blood loss.

2. Preoperative evaluation

Etiology of loss of hearing should be ascertained in pediatric patients. Those with identifiable syndromes may be at risk for having a difficult airway (Treacher-Collins, Pierre Robin). Additionally, the syndrome may include cardiac, pulmonary, or neurological involvement (i.e., CHARGE syndrome). Adult patients who are obese may be at risk for obstructive sleep apnea and may obstruct if sedated under a drape in an unattended airway. Elderly patients may be at risk for ischemic heart disease or COPD. Report of poor exercise exercise tolerance should be evaluated to ascertain if the condition is chronic or acute.

Delaying surgery may be indicated if the patient is suffering from any unstable condition. Although there is controversy surrounging children with URIs, placement of PE tubes has been routinely performed using mask anesthesia if the child is afebrile and there are no abnormal ascultatory findings on chest exam. Patients with active URI who require intubation are at risk for perioperative pulmonary complications; however, the clinical impact may be difficult to impossible to predict. Elderly patients with coronary artery stents placed within 1 year who have discontinued dual antiplatelet therapy or patients with undiagnosed sleep apnea scheduled for ambulatory surgical procedures in a freestanding center or office may benefit from delay to reschedule to an inpatient facility.

3. What are the implications of co-existing disease on perioperative care?

Perioperative evaluation

Surveillance for syndromic anomalies of airway, heart, and lungs
Preoperative hemoglobin (unnecessary for pediatric PE tubes)
Consideration of echocardiogram for evaluation of ventricular function and RVSP in obese patients with poor exercise capacity
Polysomnogram is gold standard for diagnosis of obstructive sleep apnea for obese patients with large neck circumference (if considering discharge to an unmonitored environment)Perioperative risk reduction strategies-

Preoperative optimization of comorbidities

Assessment of risk for postoperative nausea and vomiting with aggressive prophylaxis and treatment
Minimize oral intake immediately postoperatively
Minimize visual stimulation postoperatively in patients undergoing stapedotomy
Consider use of lorazepam for severe postoperative vertigo with nystagmus

b. Cardiovascular system

Acute/unstable conditions: Proceed only if delay of procedure is life threatening such as infection involving brain or meninges

Baseline coronary artery disease or cardiac dysfunction – Goals of management: Cardiac revascularization not shown to be beneficial to decrease risk. Cardiac testing per AHA/ACC guidelines. Goals of management include normotensive patient with controlled heart rate under 80 bpm.

c. Pulmonary

COPD

Encourage smoking cessation. Optimization with good pulmonary toilet. Patients with severe obstructive disease or who are dependent on supplemental oxygen may not be good candidates for outpatient procedures.

Reactive airway disease (Asthma)

Patients should avoid exposure to known allergens preoperatively. Consideration of preoperative burst of oral steroids (0.5 mg/kg/day for 3 days prior to the procedure) for those with severe asthma or for those who have required oral steroids for treatment of asthma within the last year.

d. Renal-GI:

No special considerations

e. Neurologic:

Patients with mastoid infection may be at risk of meningitis. Intraoperative dural rents can occur during procedures of the ear. In rare circumstances, may require hyperventilation of the intubated patient and use of mannitol to facilitate surgical repair. Postoperative nystagmus can occur in conjunction with vertigo.

f. Endocrine:

No special considerations

g. Additional systems/conditions which may be of concern in a patient undergoing this procedure and are relevant for the anesthetic plan?

Cochlear implant devices are placed under general anesthesia. During this and several other otological procedures, the integrity of the facial nerve is monitored intraoperatively. Muscle relaxants cannot be used for these procedures; however, the surgical field must be completely quiescent during meticulous work done under a microscope. Frequently, the depth of anesthesia required to render the patient immobile without the use of muscle relaxants results in hypotension requiring fluid and pressor therapy. This is especially true in the elderly population who are frequently on antihypertensive medications.

4. What are the patient's medications and how should they be managed in the perioperative period?

Perioperative medications are managed to decrease risk of hemodynamic instability, pulmonary aspiration, and bleeding.

h. Are there medications commonly seen in patients undergoing this procedure and for which should there be greater concern?

Elderly patients may be on chronic antihypertensive medications or drugs to manage ischemic heart disease. Of those medications, the ACE Inhibitors and the ARBs can be particularly troublesome due to vasoplegia that is unresponsive to fluid and commonly used pressors. Treatment with methylene blue (2 mg/kg single bolus dose given over 20 minutes) or vasopressin (0.01-0.04 unit/min) may be of benefit to restore normal blood pressure values.

i. What should be recommended with regard to continuation of medications taken chronically?

Cardiac

Administer beta blockers
Diuretics are held unless part of regimen for CHF
ACE inhibitors and ARBs: Hold morning of surgery unless part of regimen for CHF (controversial)
Administer calcium channel blockers
Administer clonidine

Pulmonary

Administer prescribed inhaled beta agonists
Administer prescribed inhaled steroids
Consider oral steroids for severe asthmatic (see above)
CPAP-dependent patients with OSA should bring their device to the facility on the day of surgery and apply postoperatively

Renal

No special considerations

Neurologic

Continued per routine

Antiplatelet

Disconitnue Plavix (clopidogrel) 5-7 days prior to the procedure and continue ASA 81 mg per AHA/ACC guidelines (although most ENT surgeons will ask that the ASA be held as well 7 days prior to the procedure).

Psychiatric

Continue per routine except MAO inhibitors (discontinuation contingent on risk of acute patient psychiatric decompensation)

j. How To modify care for patients with known allergies –

Patients with egg allergies may have cross reactivity with propofol. Alternative induction and maintenance medications should be considered. In patients with local anesthetic and narcotic allergies, consider using alternative class (i.e., amide versus ester, semisynthetic narcotic versus morphine).

k. Latex allergy- If the patient has a sensitivity to latex (eg. rash from gloves, underwear, etc.) versus anaphylactic reaction, prepare the operating room with latex-free products.

N/A

l. Does the patient have any antibiotic allergies]

Prophylactic antibiotic therapy is not warranted for clean or clean-contaminated otological procedures.

m. Does the patient have a history of allergy to anesthesia?

Malignant hyperthermia (MH)

Documented: Avoid all trigger agents such as succinylcholine and inhalational agents:

Family history or risk factors for MH: Treat as though MH susceptible until testing performed.
Local anesthetics/ muscle relaxants: Consider alternative to class of drug with documented allergy. Succinylcholine is contraindicated in patients with history of pseudocholinesterase deficiency and should be avoided in cases were the patient has a first-degree relative with known deficiency but has not yet been tested.

5. What laboratory tests should be obtained and has everything been reviewed?

No special laboratory testing is required unless indicated by patient comorbidity.

Common laboratory normal values will be same for all procedures, with a difference by age and gender.

Intraoperative Management: What are the options for anesthetic management and how to determine the best technique?

a. Regional anesthesia

With the exception of surgical field block, regional anesthesia is not an option.

b. General Anesthesia

Benefits: Surgical field quiescent, patient comfortably unaware of anxiety-provoking sounds such as the drill. If the patient is deaf, decreased anxiety from inability to effectively communicate intraoperatively.

Drawbacks: Potential for increased nausea and vomiting.

Patients on multiple medications may experience intraoperative hypotension if muscle relaxant is contraindicated.

Deaf patients may experience confusion on emergence. It may be difficult to ascertain the patient’s ability to “follow command” during this period or to reassure them.

Airway concerns: “Bucking” upon emergence may result in increased bleeding or damage to the surgical procedure.

c. Monitored Anesthesia Care

Benefits: Decreased incidence of nausea and vomiting. Decreased recovery time in PACU.

Drawbacks: Inability to communicate with patients who are deaf intraoperatively. Patients with undiagnosed OSA may be at risk for obstructive episodes while draped with head turned away from anesthesia provider. Patients with acute decrease in responsiveness due to change from moderate to deep sedation or general anesthesia may require interruption of the surgical procedure for airway intervention.

Difficult to tritrate nitrous oxide if the surgeon requests its use, although usually the request is for it to be discontinued.

6. What is the author's preferred method of anesthesia technique and why?

Please define jolly tube

What prophylactic antibiotics should be administered?

Prophylactic antibiotics are not warranted for clean or clean contaminated otological procedures.

What do I need to know about the surgical technique to optimize my anesthetic care?

Constant communication with the surgeon is paramount is providing optimal anesthetic care. While potent inhaled anesthetics are frequently used for these procedures, the use of nitrous oxide may be detrimental to the surgical repair, especially if it is not discontinued prior to placement of the graft during tympanoplasty.

What can I do intraoperatively to assist the surgeon and optimize patient care?

Minimize or avoid any unnecessary movement to the operating room table during the use of the microscope. Remifentanil infusion may reduce the incidence of intraoperative patient movement when used with sevoflurane. The surgeon may ask for frequent changes in the position of the bed to assist in surgical exposure.

What are the most common intraoperative complications and how can they be avoided/treated?

Inadvertent disconnection of anesthesia circuit under drapes during general anesthesia. Prior to placement of drapes, check to make sure all connections are tight. Consider use of jolly tube if head movement by the surgeon is anticipated.
Inadvertent intravascular injection of epinephrine containing local anesthetic can lead to hemodynamic instability and malignant dysrhythmias. Surveillance during local anesthetic administration with prompt identification and treatment can minimize or preclude adverse sequelae. If this occurs, request that the surgeon immediately discontinue further administration of local until the derangement has abated.
Intraoperative bleeding can occur and may be difficult to control. Request the surgeon to pack the wound until adequate venous access is obtained and the patient is stabilized.

Cardiac complications: Rare, cardiac ischemia, MI, CVA, or death due to inadvertent intravascular injection of epinephrine as noted above.

Pulmonary: None commonly unique to otological procedures.

a. Neurologic:

Postoperative tear in the dura may result in postoperative positional headache and dizziness. Profound vertigo with intractable nausea and vomiting may require admission and treatment with promethazine (12.5-25 mg IV q 4-8 hours), diphenhydramine (10-50 mg IV q 4-6 hours), or lorazepam (0.5-2.0 mg IV q 4-8 hours).

b. If the patient is intubated, are there any special criteria for extubation?

Consider deep extubation when appropriate and when patient Valsalva may be detrimental to the surgical repair.

c. Postoperative management

What analgesic modalities can I implement?

Acetaminophen (10-15 mg/kg) is frequently a sufficient analgesic for many minor otological procedures such as PE tubes in infants.
For severe pain, narcotic analgesics (fentanyl 1-2 mcg/kg) are effective; however, opioids are known to increase the incidence of nausea and vomiting.
Nonsteroidal anti-inflammatory drugs are generally discouraged in the immediate postoperative period due to concern of bleeding.

What level bed acuity is appropriate?

The majority of single-procedure otological surgeries are performed on a outpatient basis. For patients with comorbidities mandating postoperative observation, level of care is determined by acuity of the patient’s preoperative condition.

What are common postoperative complications, and ways to prevent and treat them?

Postoperative nausea and vomiting are common after otological procedures. Aggressive prophylaxis against nausea and vomiting intraoperatively uses multimodal therapy.
Patients may experience hypertension in the PACU due to systemic absorption of injected local anesthetic and epinephrine mixture and may require treatment with short-acting medications.
Assessment for facial nerve injury/palsy may not be accurate in the immediate postoperative period due to presence of local anesthetic.
Patient or family members may c/o “migrating” rash on the patient’s neck and chest ipsilateral to the surgical repair that comes and goes in the PACU. This is likely due to epinephrine redistribution from the local anesthetic mixture and resulting vasoconstriction and dilatation and will spontaneously resolve, requiring only reassurance.

What's the Evidence?

Dornhoffer, J, Manning, L. “Unplanned adsmissions following outpatient otologic surgery: the University of Arkansas experience”. Ear Nose Throat J. vol. 79. 2000 Sep. pp. 710-7.

Kamizato, K, Kakinohana, M, Saikawa, S, Madanbashi, Y, Oda, H, Sugahara, K. “Remifenanil can reduce introperative movement during tympanoplastic surgery–a retrospective analysis”. Masul. vol. 59. 2010 Jun. pp. 707-10.

Tait, AR, Knight, PR. “The effects of general anesthesia on upper resipratory tract infections in children”. Anesthesiology. vol. 67. 1987 Dec. pp. 930-5.

Homer, RJ, Elwood, T, Peterson, D, Rampersad, S. “Risk factors for adverse events in children with colds emerging from anesthesia: a logistic regression”. Paediatr Anaesth. vol. 17. 2007 Feb. pp. 154-61.

Swartz, R, Longwell, P. “Treatment of Vertigo”. AFP. vol. Vol. 71.

No sponsor or advertiser has participated in, approved or paid for the content provided by Decision Support in Medicine LLC. The Licensed Content is the property of and copyrighted by DSM.

Jump to Section