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ANESTHESIA FOR ORTHOPEDIC,ENT AND MAXILLOFACIAL SURGERY Presented by-DR.POOJA Moderator-DR.GIRISH SHARMA ANESTHESIA FOR ORTHO SURGERY Patients range from elderly patient with multiple co morbid conditions to a young apparentely healthy patient All patient need a thorough pre-op evaluation Challenges include - difficult airway - large blood losses - positioning -significant post-op pain ELDERLY PATIENT Are more prone to cardiac, pulmonary complications and dementia/delirium cardiac complications because of -Co morbid condition -Limited functional capacity -Significant blood loss and fluid shift -Systemic inflammatory response -Post op pain All these trigger a stress response leading to tachycardia, hypertension, increased O2 demand and myocardial ischemia. pulmonary complications due to - Age related changes in lung mechanics - Decrease in arterial O2 tension - Decrease of 10% in FEV1 with each decade of life -Increase in closing volume Confusion or delirium-risk factors include- advancing age - alcohol use - pre op cognitive impairment - periop hypoxemia - hypotension - hyper volemia - electrolyte imbalance - infections - sleep deprivation - pain - medications Strategies to reduce incidence include -identifying risk factors -adequate pain control -mobilization -maintaining normal sleep -avoiding psychotropic medications SPECIAL CONSIDERATION Fat Embolism Syndrome Pneumatic Tourniquets Deep Vein Thrombosis and PE Bone Cement Implantation Syndrome FAT EMBOLISM SYNDROME Fat embolization is a well known complication of skeletal trauma and surgery involving femoral medullary canal FES is a physiologic response to fat within systemic circulation Embolization occurs in almost all patients with pelvic or femoral fracture but FES in <1% . GURD,S DIAGNOSIS- major feature(at least one) respiratory insufficiency, cerebral involvement, petechial rash Minor features(at least four) pyrexia, tachycardia, retinal changes, jaundice, renal changes LAB featuresFat microglobulinemia (required) anemia, thrombocytopenia, high ESR SCHONFELD FES INDEX Petechial rash Diffuse alveolar infiltrate Hypoxemia PaO2<70mmHgFiO2100% Confusion Fever>38C HR>120 RR>30 Score >5 is diagnostic 5 4 3 1 1 1 1 It can be gradual over 12-72hrs or fulminant leading to ARDS and even cardiac arrest Treatment includes – -early stabilization of fracture -O2 therapy -early mechanical ventilation before respiratory failure -Steroid therapy may be benefecial PNEUMATIC TOURNIQUETS Used to create blood less field Inflation pressure is 100mm above systolic BP Prolonged inflation (>2hrs) leads to -transient muscle dysfunction - rhabdomyolysis, -nerve injuries Exsanguination of extremity causes shift of blood volume into central compartment , rise in CVP and arterial BP that may not be well tolerated in pat. with LV dysfunction. . Tourniquet pain –even during GA manifesting as increasing MAP beginning about ¾-1hr of cuff inflation Cuff deflation causes fall in CVP and arterial BP Washout of metabolic wastes in ischemic extremity increases PaCO2, ETCO2,lactate and potassium levels Can cause increase in minute ventilation and rarely dysrythmias DVT and PE may develop DEEP VEIN THROMBOSIS AND THROMBO EMBOLISM Risk factors include -obesity -age >60 -lower extremity fracture -tourniquet use -immobilization >4days Prophylactic anticoagulation ,pneumatic leg compressions ,early mobilization reduce the incidence BONE CEMENT IMPLANTATION SYNDROME Manifesting as hypotension, hypoxia, FES or even cardiac arrest Mech. Includes -embolization of bone marrow debris during pressurization of femoral canal -toxic effect of methyl methacrylate -release of cytokines Risk factors are -revision surgery -pathological fracture -preexisting pulmonary hypertension -quantity of cement used Strategy to minimize - increasing FiO2 prior to cementing - maintaining euvolemia - high pressure lavage of femoral shaft - creating vent in distal femur - cement less prosthesis SPECIAL CONDITIONS RHEUMATOID ARTHRITIS – -airway(limited TMJ movement, narrow glottic opening) -Cervical spine (atlanto axial instability)-pre op flexion extension x-ray in limited neck movement if instability exceeds 5mm awake fibroptic intubation with neck stabilization -Cardiac(pericarditis , tamponade) -Pulmonary(interstitial fibrosis) -Renal insufficiency ANKYLOSING SPODYLITIS-chronic inflammatory arthritic disease resulting in axial skeleton fusion airway management difficult due to reduced movement of cervical spine and TM joint Neuraxial anesthesia difficult because ossification of spinal ligament closes inter vertebral spaces which may block acces to epidural and spinal space In some cases caudal may be feasible ACHONDROPLASIA-dwarfism ,kyphoscoliosis and fo ramen magnum stenosis Chronic hypoxemia hypercarbia due to airway obstruction leads to pulmonary hypertension -awake fibroptic intubation is safe - Echo should be obtained to asses pulmonary hypertension and intracardiac shunts -aggravating pulmonary hypertension is to be avoided OSTEOGENESIS IMPERFECTA -fragility of tissues and bones require extreme care in positioning and padding during anesthesia -Intubation with minimal neck manipulation -Sch avoided because fasiculations can cause fractures -Bleeding status should be evaluated because of platelet abnormality -Aggressive hydration because of risk of hyperthermia and MH REGIONAL VERSUS GA Reduced incidence of DVT and PE Less blood loss Less respiratory complications Superior post op analgesia Conscious pat aid in comfortable positioning Manipulation of airway avoided Full anticoagulation is a contraindication Interval of 12hrs bw LMW and neuraxial block Epidural catheter removal 8-12hrs of LMW Admn and 1-2hrs before next admn SPINAL SURGERIES Problems include related to positioning-airway management difficult Eyes pressure CRAO, CRVO, corneal abrasion Neck rotation –compromized blood flow to brain Large blood losses-controlled hypotensive anesthesia is used. adequacy of end organ perfusion to be maintained with invasive BP,UO and ABG analysis ANESTHESIA FOR ENT SURGERIES Clear, free, unobstructed airway is the principal concern of these procedures Pt. may present with airway obstruction or distorted anatomy During surgery anesthetist is away from airway making adjustment difficult Significant head extension and lateral rotation may be required During intraoral procedures ,instruments to open mouth obstruct airway Airway requires protection from blood and secretions in intraoral and nasal procedures EAR SURGERY Op. range from short procedures to more long and complex procedures Anesthetic factors are-Choice of airway -Use of nitrous oxide -Head and body position -Facial nerve monitoring -Adequate surgical field -Nausea and vomiting -DVT prophylaxis -Temp. control For long procedures tracheal tubes are used to secure the airway. Reinforced tubes may be used to prevent kinking with head rotation Nitrous diffuses to airspaces in body it can diffuse into middle ear cavity increasing pressure and upon discontinuation rapid absorption leading to negative pressure resulting in graft displacement so avoided during graft procedures Head up tilt of 15 degree is useful to reduce venous pressure and improve operating field Lat. tilt of OT table helps prevent extreme rotation of neck For facial nerve monitoring it may be required to reverse the NM block High incidence of PONV so adequate hydration and prophylactic anti emetics NASAL SURGERY Potential to contaminate lower airway with blood and secretions Airway is secured with tracheal tube and throat pack is inserted Extubation is done awake or deep Awake involves removal of tube when pt. responds to commands and make attempts to remove the tube advantages is airway control in awake pt. with return of laryngeal reflexes Disadvantages include high incidence of coughing, bucking,de saturation , laryngo spasm deep extubation leaves unprotected airway pt. is dependent on oro pharyngeal airflow due to nasal packing recovery with a LMA At end of surgery pack should be carefully removed Laryngo scopy followed by neck flexion to encourage any clot to fall past soft palate and direct visualization of suction catheter going behind soft palate Any clot left behind can be aspirated after tube removal causing total airway obstruction and death called coroners clot Endoscopic procedures for vocal cord pathology including polyp, nodules, tumours ,tracheal stenosis Preoperative airway assesment information about sub glottic ,tracheal lesions by CXR,CT,MRI sedative premedication avoided in airway obstruction profound muscle paralysis to provide masseter muscle relaxation for introduction of scope and immobile surgical field OXYGENATION AND VENTILATION Most commonly pt. is intubated with small diameter tracheal tube If intubation interfering with procedure ,there are various non intubation techniques Spontaneous ventilation and insufflation tech.useful in FB aspiration,glottic and sub glottic lesions removal O2 admn by facemask with inhalation induction and spontaneous ventilation Small catheter introduced into nasopharynx Tracheal tube cut short ,placed in nasopharynx just beyond soft palate Nasopharyngeal airway Side-arm of laryngoscope or bronchoscope JET VENTILATION TECH. attachment of jetting needle to laryngoscope for supra glotic insufflation Trans tracheal jet ventilation through percutaneous catheters sub glottic ventilation through catheter or tube placed in glottis LOCAL ANESTHESIA OF AIRWAY If awake intubation is needed , local anesthesia of airway can be used Block of superior laryngeal nerve b/l with trans laryngeal injection of LA provides anesthesia from infra glottic area to epiglottis SUPERIOR LARYNGEAL NERVE BLOCKhyoid bone displaced laterally to the side to be blocked 25G 2.5cm needle walked of greater cornu of hyoid bone inferiorly and advanced 23mm As it passes through thyro hyoid membrane LOR is felt 3ml LA injected TRANSLARYNGEAL BLOCK-cricothyroid membrane is located 20G or smaller catheter over needle is introduced into midline .Inner cannula is withdrawn ,catheter held firmly in place,air is aspirated 3-5ml of 4%lignocaine is injected Vigorous cough results which aid in spread of LA GLOSSOPHARYNGEA NERVE BLOCK-22G spinal needle is used to inject LA into post. Tonsillar pillar INTRAORAL SURGERIES Tonsillectomy is frequentely performed procedure pre op evaluation to identify OSA, active infection, bleeding tendency ,anemia Surgery be postponed for RTI Sedation to be avoided in OSA Adequate depth of anesthesia to be maintained EXTUBATION After careful inspection and laryngoscopy to ensure no blood clots are present child placed in left lat. or semiprone head down position pillow is placed under chest to drain secretions chances of laryngospasm are greater –topical airway ,increasing depth of anesthesia, subhypnotic doses of propofol or lidocaine can be used Chances of rebleeding are greater in first six hours Problem because of hypovolemia,aspiration risk and difficult laryngoscopy Senior’s help should be requested O2 started, adequate resuscitation, hematocrit and coagulation checked ,blood cross matched Large bore iv asses established RSI is preffered tech. Difficult laryngoscopy intubation anticipated Small tracheal tube should be available Tracheostomy set with surgeon should be there Gastric tube should be inserted to decompress stomach Extubation should be done fully awake ANESTHESIA FOR MAXILLOFACIAL SURGEY Priority is to clear and secure the airway Severe bleeding can occur and there is risk of aspiration of blood, bone,loose teeth ,soft tissue fragments Detailed preop airway evaluation focussing on jaw opening , mask fit , neck mobility , maxillary protrusion , nasal patency , intraoral lesions, micrognathia , macroglossia If problem with mask ventilation or intubation,airway should be secured prior to induction This may involve-fibroptic nasal intubation -fibroptic oral intubation -tracheostomy Nasal intubation should be avoided in maxillary fractures because of associated basillar skull fracture and CSF rhinorrea Intra op head up position , controlled hypotension , local infiltration with epinephrine soln. Two iv lines should be established oropharyngeal pack should be inserted Anesthetist is remote from airway as surgical field is near airway. Airway monitoring of end tidal CO2,peak inspiratory pressures , esophageal stethoscope breath sounds are important At end pack to be removed with proper suctioning Extubation is to be done once patient is fully awake If chance of post-op edema of structures interfering with airway, patient is to be left intubated DIFFICULT AIRWAY ALGORITHM 1.ASSES BASIC MANAGEMENT PROBLEM A .Difficult ventilation B. Difficult intubation C. Difficult patient co operation D. Difficult tracheostomy 2.ACTIVELY DELIVER SUPPLEMENT O2 THROUGHOUT DIFFICULT AIRWAY MANAGEMENT 3.CONSIDER BASIC MANAGEMENT CHOICES A.Awake vs intubation after GA B.Noninvasive vs invasive technique for initial approach to intubation C.Preservation of spontaneous ventilation vs ablation a-surgery with facemask or LMA, local infiltration, regional nerve block b-cricothyrotomy or tracheostomy c-use of different laryngoscope blades, stylets, tube changers, lightwand, fibroptic,retrograde, blind technique d-cancel surgery e-noninvasive ventilation-rigid bronchoscopy,transtracheal jet ventilation ,combitube THANK YOU