ANAESTHESIA FOR EAR SURGERYCOMMON SURGERIES-External ear•Removal of simple lesions•Foreign bodies in ext.auditory canal•Preauricular abnormalities•Exostoses

MIDDLE EAR AND MASTOID• Adenoidectomy• Tonsillectomy• Otitis media• Mastoidectomy• Tympanoplasty• Myringoplasty

INNER EAR• Cochlear transplant surgery

• Endolymphatic sac decompression

• Labyrinthectomy

TECHNIQUE OF ANAESTHESIA

GENERAL ANAESTHESIA• A through preoperative asessment advised.• Specific attention paid to hypertension or any

cardivascular disease which limits attempts to control BP introp.

• No specific premedication required• Anxiolytics such as alprolazam and temazepam for

anxious patients.• Beta blocker or clonidine if required can be given iv with

intraop monitoring

SPECIFIC CONSIDERTIONS..

CHOICE OF AIRWAY..FACEMASK• Earlier used for short ear surgeries such as

myringotomy and tube insertion• Was cumbersome for both anaesthesiologist

and surgeon• Improper oxygenation,theatre pollution and

inaccurate monitoring of tidal gases are major diasadvantages.

LARYNGEAL MASK AIRWAY• Flexible LMA designed for ent surgeries.• Has a flexible shaft wich is more tolerant to

head rotation and flexion and extension.• For minor procedures has an advantage over

face mask as it nullifies all disadvantages.• Proseal LMA has allowed major surgeries for

over 5 hours.

ENDOTRACHEAL TUBE• For most long duration surgeries a reinforced

or armored tracheal tube needed to prevent kinking with head rotation.

• South facing preformed tube can also be used

• Provides airway collection from debris,blood and regurgitated gastric contents.

NITROUS OXIDE• Nitrous oxide diffuses from blood to

airspaces.• Amount depends on concenteration and

duration of surgery.• Causes increase in middle ear pressures

during surgery• Excessive negative pressures after

discontinuation of N2O can cause displacement of graft.

• Underlay grafts have decreased graft displacement.

• Many anaesthesiologists use nitrous oxide<50% CONC in middle ear surgeries

POSITION• Rotation and flexion of head is necessary in

most ear surgeries• Measures to prevent compression of jugular

and carotid considered.• Lateral tilt of ot table improves surgical access.• Arms should be placed in neutral position• Head up by 15 deg reduces venous pressure

and improves operative field.

FACIAL NERVE MONITORING• Used for middle ear, mastoid and inner ear

surgeries to identify the facial nerve.• Audible and visual signals recorded in the

monitor.• Partial or complete neuromuscular blockade

abolishes this activity• Essential to reverse the nm blockade and

asssess the nerve before proceeding dissection near it.

ANTIEMETICS• Middle ear and inner procedures have a

higher complications rate• Retching and vomiting also increase venous

pressure, and icp or disrupt surgical grafts.• Opoids if possible should be avoided.• Antiemetics like

ondansetron,droperidol,scopolamine,dexamethasone and prokinetics like metoclopramide may be used.

• For all long surgeries…• Dvt prophylaxis advocated.• Temperature monitoring done• Urinary catheterisation be considered.

LOCAL ANAESTHESIA

• Can be undertaken safely in suitable patients with or without sedation

• Preop asessment and intraop monitoring same as for general anaesthesia

• Simple external,and some middle ear surgeries in LA• Light sedation with midazolam and propofol• Patient understanding and cooperation vital• LA can be in form of infiltrating lidocaine ,topical

administration of lidocaine onto tympanic membrane

NERVE BLOCKInfiltration ofAnterior and posterior meatal wall-Auriculotemporal

nerve,Greater auriculur nerve

Aural speculum-Auriculur branch of vagus

Topical application of LA-tympanic nerve

ANAESTHESIA FOR NASAL SURGERY

TYPES OF NASAL SURGERY• Procedures on external aspect of nose• “ within nasal cavity• “within nasal sinuses• “involving the bony structures

SURGERIES UNDER GENERAL ANAESTHESIA• Sinus surgeries• Rhinoplasty• Septorhinoplasty• Nasolacrimal duct surgery• Frontal sinus surgeries• Ant skull base surgeries• Cranofacial resections

SURGERIES UNDER LOCAL ANAESTHESIAProcedures on anterior septumSeptoplastyTurbinectomyCauterisationPolypectomyReduction of simple nasal fractures

Preoperative evaluation

Same for local and general anaesthesiaSpecific asessment for • Obstructive sleep apnea• Use of nasal cpap• Cardiovascular status• History of Nsaid use• Samter triad-inc incidence of brochospasm

NASAL VASOCONSTRICTORS• Reduce bleeding from from nasal mucosa• Can be used in combination with local

anaesthetics• Phenylephrine+lidocaine,lidocaine+epinephrin

e

CHOICE OF AIRWAY

Adequate throat packing be done to protect lower airway

Both flexible LMA and endotracheal tube can be used.Exam by fibreoptic scope revealed superior lower

airway protection by a correctly placed LMA than a endotracheal tube.

Towards end of surgery throat pack must be removed with careful examination of oral and postnasal space accompnied by suctioning.

EXTUBATIONExtubation of tube when pt awake or deepExtubation of flexible LMA when patient can

open mouth to command.Awake extubation(Adv-better and quicker

laryngeal reflexes and hence lesser chances of lower airway contamination)

Disadvantage-higher incidence of laryngospasm,bucking,desaturation

Deep extubation:Adv-• Improves recovery profile,• lesser chances of laryngospasmDisadvantage-• leaves an unprotected airway• dangerous in pts of OSA

POSTOPERATIVE CONSIDERATION

Almost all pts have complete or partial airway obstruction.

Significant in OSA patientsOSA patients can have nasopharangeal airway

incorporated into nasal packPain is usually mild so oral aceaminophen and a

NSAID are adequate.IV canula to be retained till removal of nasal pack

ANAESTHESIA FOR THROAT SURGERY

INTRAORAL SURGERY• TONSILLECTOMY• ADENOIDECTOMY• PALATAL SURGERYLARYNGEAL PROCEDURES• BENIGN,MALIGNANTAND STENOTIC LESIONS• AIRWAY ENDOSCOPY• LASER SURGERY

Preoperative assessment• Identify patients with OSA• Loose teeth• Vunerable dental implants• Bleeding disorders• Anaemia• Active infection• Sickle cell disease status• RTI infections inc risk of bleeding,surgery

should be postponed

GENERAL ANAESTHESIA

• Maintain sufficient of anaesthesia• IV induction with propofol,fentanyl with a short

acting muscle relaxant• Inhaled induction in uncooperative children,and

needle phobic adults• Inhalational induction can be dangerous in pts

with OSA• During procedure both spontaneous and ippv

can be used

• Oral packing must be done adequately• During spontaneous ventilation constant

observation of reservoir bag done.• Timing of extubation to reduce incidence of

laryngospasmANALGESIA:• Tonsillectomy more painful in adults ,so

adequate intraoperative and postoperative analgesia must be provided

• Intraoperative opoids usually necessary• Role of Aspirin in analgesia controversial

STEROIDS• IV dexamethasone .05-.15 mg/kg improves

recovery• Decrease postoperative emesis• Increased tolerance to regular diet• AnalgesiaANTIBIOTICSReduce fever ,halitosisEarlier return to normal oral intakeNo effect on analgesia

POSTOPERATIVE NAUSEA AND VOMITINGOndansetron,granisetron,dexamethasone have

good antiemetic effectOndansetron .15mg/kg better than

metoclopramide .25 mg/kgPt should be well hydrated and receive regular

non opioid analgesia postoperatively.

Post extubation laryngospasm and stridor• Incidence more after removal of tube than

flexible LMA• Incidence-12-25%• Methods of reducing laryngospasm• Topical lidocaine 2-4% application• IV lidocaine 1mg/kg• Administration of propofol close to extubation• IV magnesium also used

CHOICE OF AIRWAYChoice of tracheal tube,flexible LMA depend on

experience of anaesthesiologistFlexible LMA should be only used by

experienced anaesthesiologist

TRACHEAL TUBE:Southfacing endotracheal tube Most common way of airway maintainanceMore resistant to compression from mouth gagLess likely to obstruct during surgeryOccupies less space in oropharanynx than flexible

LMADuring extubation careful laryngoscopy is done with

suctioning to ensure no blood clots are presentPt placed in tonsil positionExtubation deep or awake

FLEXIBLE LMA:Requires cooperation b/w anaesthesiologist and surgeonCare required during placement of surgeonMechanical obstruction by tonsilar gag in 2-20%ADVANTAGES • Avoidance of muscle relaxant• Superior recovery profile,fewer episodes of

bronchospasm,laryngospasm,bleeding,desaturation• Less aspiration of blood• Better protection of lower respiratory tract than endotracheal

tube

Flexible LMA removed when pts open their eyes to command

Anaesthetic considerations for Bleeding tonsil• Incidence of postop haemorrhage increase

with age• Primary bleeds occur within 6 hrs of surgery• Bleeding is usually venous or capillary• Signs are tachycardia,hypotension,excessive

swallowing,pallor ,restlessness,airway obstuction

• Help of a senior anaesthesiologist seeked

• Pts should be given oxygen• Large bore IV access should be established.• Haemoglobin ,haematocrit ,coagulation status assessed.• laryngoscopy can be difficult because of

clots.continuous oozing,intraoral swlling.• Post resustication RSI is preferred.• Smaller sized ET tubes should be available• After intubation ryle tube inserted to evacuate

swallowed blood• Inhaled induction difficult is lateral position• More chances of laryngospasm• Extubation done when pt fully awake.

ANESTHESIA FOR LARYNGEAL SURGERIES

Anesthesiologist and the surgeon are working in the same anatomic field

P ts presentwith minor vocal cord lesions to elderly patients with glottic carcinoma and stridor

The anesthesiologist has to maintain oxygenation, remove carbon dioxide, protect the airway, and keep the patient anesthetized, while the surgeon is operating in the same area.

Cooperation and communication between the anesthesiologist and the surgeon are essential for success.

VOCALCORD PATHOLOGIES 1.Nodules. 2. Polyps 3. Cysts. 4. Granulomas. 5. Papillomas. 6. Malignant

Preoperative Assessment

Anesthesiologist should have some idea of the size, mobility, and location of the lesion

Standard airway assessments to predict the ease of ventilation, visualization of the laryngeal inlet, and tracheal intubation should be performed.

Airway pathology and its impact on airway severity and size of lesions at the glottic level are assessed by direct or indirect laryngoscopy.

Subglottic and tracheal lesions assessed by chest radiography, computed tomography (CT), and magnetic resonance imaging (MRI).

Assessment Implication History of endoscopic procedures -Any previous difficulty is significant,

and anesthetic records should be reviewed to assess severity and site of obstruction, vascularity of lesion, and previous anesthetic techniques used

Hoarse voice -Nonspecific symptom; patients can be hoarse with only minor lesions on the vocal cord or have significant vocal cord pathology and airway compromise

Voice changes- Nonspecific symptom; minor lesions can result in significant voice changes

Dysphagia- Significant and suggests supraglottic obstruction; if associated with carcinoma implies upper esophageal extension

Altered breathing position- Significant; patients with partially obstructing lesions compensate by changing their body positioning to limit airway obstruction

Unable to lie flat Significant- suggests severe airway obstruction, and patients may need to sleep upright

Breathing during sleep -Significant; difficulty in breathing at night or waking up at night in a panic suggests severe obstruction

Stridor- Significant; indicates critical airway obstruction with >50% reduction in airway diameter and in adults an airway diameter of 4-5 mm

Stridor on exertion -Significant; suggests airway obstruction is becoming critical; patients may have no stridor at rest

Stridor at rest Significant- critical airway obstruction is present Inspiratory stridor- Significant; suggests extrathoracic airway

obstruction Expiratory stridor- Significant; suggests intrathoracic airway

obstruction

• Absence of stridor- Generally reassuring, but in exhausted adults and children there are limited chest movements and insufficient airflow to generate enough turbulent flow for stridor

• Fiberoptic awake flexible laryngoscopy - Necessary for All adult patients should have this to visualize the vocal cords,great care must be taken to avoid local anesthetic and fiberscope contact with the vocal cords, precipitating total airway obstruction

• Chest x-ray/CT/MRI scans- Can identify severity and depth of glottic, subglottic, tracheal, and intrathoracic lesions

ANAESTHETIC CONSIDERATIONS FOR ENDOSCOPY

Technique depends on Pt general conditionSize mobility and location of lesionUse of laserSurgical requirements

An ideal technique:(1)Is simple to use(2)Provide complete control of the airway with no risk of aspiration; (3) Control ventilation with adequate oxygenation and carbon

dioxide removal; (4) Provide smooth induction and maintenance of anesthesia; (5) Provide a clear motionless surgical field, free of secretions; (6) Not impose time restrictions on the surgeon; (7) Not be associated with the risk of airway fire or cardiovascular

instability; (8) Allow safe emergence with no coughing, bucking, breath

holding, or laryngospasm; (9) Produce a pain-free, comfortable, alert patient at the end of the

operation.

Cuffed tube protects airway but can obscure view

Most of them are not laser safeAnaesthetic techniques classified into 1. Closed system2. Open system

Closed system: cuffed tracheal tube is employed with protection of the lower airway

Open system:cuffed tracheal tube is absent using either spontaneous ventilation and insufflation techniques or muscle paralysis and jet ventilation.

Advantages of closed system(1)routine technique for all anesthesiologists,(2) protection of the lower airway, (3) control of the airway, (4) control of ventilation, (5) minimal pollution by volatile agents

Disadvantages: (1) surgical access and visibility of the lesion

may be limited, (2) high inflation pressure may be required

through small tubes, (3) tube-related damage to the vocal cords

during intubation, (4) risk of a laser airway fire.

Advantages of an open system (1) laser safety, (2) reduced risk of tube-related trauma, (3) complete laryngeal visualization. The disadvantages are (2) an unprotected lower airway and (2) specialist knowledge, equipment, and

experience are required.

Closed System—Intubation Techniques Microlaryngoscopy Tubes • Are long, have a small internal and external

diameter• Designed specifically for endoscopy

procedures. 4- to 5-mm internal diameter tubes with high-volume, low-pressure cuffs used in nasal or oral versions.

• Not suitable for laser surgery

LASER TUBES:• Lasers used for the resection of papillomas,

vascular lesions of the vocal cord, granulomas, and laryngeal carcinoma.

• Carbon dioxide lasers are the most commonly used in airway surgery

• Laser-proof tube is the all-metal Norton tube, which has no cuff.

• Most laser tubes have laser-resistant properties around the shaft

• Cuff is the least protected part of the tube

Open Systems—Nonintubation TechniquesSpontaneous Ventilation and Insufflation

Technique:Useful in the removal of foreign bodiesEvaluation of airway dynamics (tracheomalaciaRemoval of noncompromised glottic and

subglottic lesions. Requires a spontaneously breathing patient and

provides a clear view of an unobstructed glottis

TECHNIQUE IN OPEN SYSTEM

Inhaled induction is begun with sevoflurane in 100% oxygen

At suitable depth laryngoscopy performed with topical lignocaine administration above and below the vocal cords

One hundred percent oxygen is administered by facemask with spontaneous ventilation

Anesthesia is continued with inhalation (insufflation) or an intravenous route (propofol infusion).

At a suitable depth the surgeon undertakes laryngoscopy or bronchoscopy

Routes of insufflation: (1) A small catheter introduced into the

nasopharynx and placed immediately above the laryngeal opening

(2) A tracheal tube cut short and placed through the nasopharynx emerging just beyond the soft palate

(3) A nasopharyngeal airway(4) The side-arm or channel of a laryngoscope or

bronchoscope.

Limitations of spontaneous ventilation or insufflation techniques:

1. Lack of control over ventilation and the potential for airway soiling.

2. Operating room pollution secondary to insufflation of volatile agents

3. May be unsuitable for large, soft, floppy lesions, particularly in the supraglottis or glottis, which may obstruct the airway after the onset of general anesthesia with spontaneous ventilation.

JET VENTILATION TECHNIQUESSUPRAGLOTTIC JET VENTILATION

SUBGLOTTIC JET VENTILATION

TRANSTRACHEAL JET VENTILATION

SUPRAGLOTTIC JET VENTILATION A technique in which the jet of gas emerges in

the supraglottis by attachment of a jetting needle to the rigid surgical suspension laryngoscope.

High-frequency or low-frequency ventilation can be used.

Allow a clear, unobstructed view for the surgeon with no risk of a laser airway fire

Use of LMA provides a smooth recovery from anaesthesia

LIMITATIONS:(1) Misalignment of the suspension laryngoscope to the

glottic inlet, which results in poor ventilation (2) Risk of gastric distention with entrained air(3) Blood, smoke, and debris are blown into the distal

trachea (4) Considerable vibration and movement of the vocal

cords occurs, which may require ventilation to be stopped while operating

(5) Inability to monitor end-tidal carbon dioxide concentration; and

(6) Risk of barotrauma with pneumomediastinum, pneumothorax, and subcutaneous emphysema.

Subglottic Jet VentilationAllows delivery of a jet of gas directly into the

trachea by the placement of a small catheter through the glottis and into the trachea

ADVANTAGES-More efficient than supraglottic jet ventilation 1. Reduced driving pressures2. Minimal vocal cord movements3. A good surgical field4. No time constraints for the surgeon in the

placement of the rigid laryngoscope

Disadvantages: 1. Potential for a laser-induced airway fire2. Presence of a potential fuel source within

the airway, and a greater risk of barotrauma than in supraglottic jet techniques.

TRANSTRACHEAL JET TECHNIQUESUnder local anaesthesia for significant airway pathologyUnder GA for elective laryngeal surgeryLimitations:• carry the greatest risks of barotrauma. • blockage• kinking• infection• bleeding • failure to site the catheter

Inhaled Foreign BodiesForeign body aspiration is the most common

indication for bronchoscopy in children 1 to 4 years old.

foreign bodies can lodge in the larynx, trachea, main bronchi, or smaller airways

effects depend on the duration, degree, and sitepresent with acute dyspnea, stridor, coughing,

and cyanosis.

ANAESTHETIC CONSIDERATIONS:

Spontaneous ventilation preferred to reduce the chances of the foreign body being pushed distally into the airway

And intermittent positive-pressure ventilation may be needed

Sedative premedication should be avoided because it may precipitate total airway occlusion.

Induction is usually by an inhaled technique with sevoflurane or halothane in oxygen

At a deep plane of anesthesia, laryngoscopy is performed, and topical local anesthetic (lidocaine) is administered

Intravenous anticholinergic agents (atropine, 20 µg/kg, or glycopyrrolate, 10 µg/kg) dec.secretions and reflex bradycardia associated with airway instrumentation.

Correct depth of anaesthesia maintained in the procedure by IV propofol

Some bronchoscopes allow the attachment of a T-piece to a side arm on the bronchoscope

Oxygen and volatile agent can pass directly into the distal trachea through them

In some bronchoscopes insufflation techniques are required for ventilation

IV dexamethasone .1mg/kg to reduce airway edema postoperatively.

Humidified oxygen and antibiotics also needed postoperatively

In some pts hdu care may be required for intensive monitoring

HEAD AND NECK SURGERYLaryngectomyPharyngolaryngectomy Radical neck dissectionResection of large thyroid lesions

GENERAL CONSIDERATIONS

More than 80% of laryngeal and oropharyngeal cancers are found in men 40 to 75 years

Greater than 97% of patients are smokers with a high alcohol intake.

Patients may have had Previous radiotherapy and surgery resulting in altered anatomy, tissue edema, induration, and “stiff” tissues

PREOPERATIVE EVALUATIONassessment of alcohol intakeuse of tobacconutritional statuselectrolyte disturbance. chronic obstructive pulmonary disease,

hypertension, and coronary artery disease, should be assessed.

Intraoperative considerations

Major surgeries involve potential for blood loss.Monitoring including intra-arterial blood pressure and

central venous pressure should be strongly considered.CVP lines should be placed in anticubital or femoral veinSurgical manipulation around carotid sinus can produce

reflex bradycardia or even asystoleIn the above case surgery should be stopprd and

resustication startedLocal infiltration of lignocaine can also be done

prophlactically.

Some degree of hypotension is usually requiredCan be achieved with inhaled agents and a 10-

to 15-degree head-up tilt aiming for systolic blood pressures of around 85 to 90 mm Hg.

A remifentanil infusion also is very effective in controlling the stress response during surgery

HEAD AND NECK DIFFICULT AIRWAYCaused by numerous disease states at different

levels within the airwayNo single anesthetic management technique can

be used safely in all patients.

LEVEL OF OBSTRUCTION:(1) Oral cavity(2) Oropharynx (3)(3) Tongue base and supraglottis(4) Glottis(5) Subglottic and upper trachea(6) Midtracheal (7) Lower tracheal and bronchial.

Oral Cavity and Oropharyngeal LesionsSmall oral lesions such as tonsilar carcinoma

usually do not obstruct the airway.Standardised airway management rechniques

may be adequate for non compromised For larger lesions in the oral cavity, partial or

near-complete airway obstruction can be a feature

Iv induction causes loss of airway toneLarge lesions cause an inability to oxygenate

hence facemask may not be helpful

Passage of an oral or nasal airway past large, obstructing, vascular, necrotic oral tumors causes trauma and bleeding

An awake fiberoptic intubation technique is often used in this group of patients

Other anesthetic techniques include awake transtracheal catheter placement with jet ventilation and awake tracheostomy

Abscess and Ludwig's Angina:Minor abscess causes pain and swelling only.Abscesses around the peritonsillar area also may

lead to airway compromise with obstruction, trismus, dysphagia, and severe pain.

Aspiration under local anesthetic may be possible, but extensive surgery may need to be done under general anesthesia

For patients without airway compromise, an intravenous induction with careful laryngoscopy and tracheal intubation, avoiding rupture of the abscess, can be done

If airway compromise or anatomic distortion is present, an awake fiberoptic nasotracheal intubation technique or tracheostomy under local anesthetic indicated.

Tongue Base and Supraglottic LesionsEven small lesions can have significant effect on

the airwayDanger from IV induction is loss of supportive

tone.An oral or nasal airway may be ineffective in

relieving the obstructionAn oral or nasal airway may be ineffective in

relieving the obstructionA strong jaw thrust maneuver may be required

Standard curved blade laryngoscopy can traumatize any lesion at the tongue base and valleculae

Straight blade may also be ineffective in distorted epiglottis

In pts with suspected supraglottic airway compromise-

awake fiberoptic intubationawake transtracheal catheterawake laryngeal block with direct laryngoscopy an awake local anesthetic tracheostomy

Glottic LesionsLaryngeal pathology with T1,T2 lesions can be

managed with conventional airway management techniques-

IV induction with cuffed ET tube“ tracheostomy tubeSupraglottic and subglottic jet ventilation for

biopsy

Options limited in advanced lesions or airway compromise

Awake fiberoptic intubation techniques have an associated morbidity and mortality

Inhaled induction for advanced laryngeal tumors with airway obstruction is difficult and challenging

Induction is slow with apneic periods, and episodes of obstruction are common.

The administration of a muscle relaxant provides optimal ventilation and intubating conditions

At a suitable depth of anesthesia, laryngoscopy is undertaken

Smaller sized ET tubes must be readyA gum elastic bougie or stylet may be useful.Failure to intubate requires an urgent

tracheostomy, and the surgeon should be gowned and immediately ready.

Transtracheal catheter placementUnder local anesthesia Catheter is placed usually at the level of the

second or third tracheal rings, avoiding the tumor and the risk of bleeding and tumor seeding.

Intravenous induction is startedJet ventilation through the transtracheal

catheter is begun