anaesthesia for bronchoscopy

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By: nethrahn (28 month(s) ago)

good one...

By: drvmagnihotri (30 month(s) ago)

a good teaching sttuf

By: drvmagnihotri (30 month(s) ago)

a good teaching sttuf

Presentation Transcript

Bronchoscopy Anaesthetic Considerations : 

Bronchoscopy Anaesthetic Considerations Dr. J. Rajesh, D.A.,DNB., Dept.of Anaesthesiology & Critical Care MMHRC

Introduction : 

Introduction Minor procedure with unique challenge to anaesthesiologist Anaesthetizing a patient who is debilitated, having multi system disease, with marginal respiratory reserve is a great challenge Sharing the airway with surgeon is added risk

Indications : 

Indications Three categories Diagnostic Therapeutic Preoperative evaluation of pathology

Diagnostic Indications : 

Diagnostic Indications Suspicion of bronchial neoplasm – most common Localized wheeze Atelectasis Persistent pneumonia Positive sputum cytology Assessment of airway After prolonged intubation – to rule out subglottic stenosis, tracheomalacia, tracheo esophageal fistula

Diagnostic Indications : 

Diagnostic Indications Tracheo bronchial tree examination after smoke injury To ascertain correct placement of endotracheal tube Difficult intubation scenario Double Lumen endotracheal tube insertion To document proper position of DLT For alveolar lavage

Therapeutic Indications : 

Therapeutic Indications Removal of aspirated foreign bodies Suctioning of copious secretions Mendelson syndrome - to aspirate particulate matter Instillation of vasoconstrictors Drainage of lung abscess Bronchial stump granulomas

Pre Operative Evaluation : 

Pre Operative Evaluation In cases of lung resection To evaluate the extent of tumor To rule out malignancy of contralateral lung

Types of bronchoscopy : 

Types of bronchoscopy Rigid ? Open type Storz ventilating bronchoscope Flexible Fiberoptic bronchoscope

Rigid vs Fiberoptic bronchoscopy : 

Rigid vs Fiberoptic bronchoscopy

Rigid bronchoscopy : 

Rigid bronchoscopy Moderate or massive hemoptysis Large foreign bodies removal In infants and small children To bypass the point of airway obstruction when airway patency is compromised by a mass Obtaining large biopsy specimen

Rigid Bronchoscopy : 

Rigid Bronchoscopy

Importance of Rigid Bronchoscope : 

Importance of Rigid Bronchoscope When the patency of airway is compromised by granulation tissue or tumor, Rigid Bronchoscope is the only instrument that can be inserted past the point of obstruction

Fiberoptic Bronchoscopy : 

Fiberoptic Bronchoscopy Improved optical resolution Improved patient comfort Can be maneuvered into peripheral zones of lung Facilitates intubation in case of difficult airway Limitations Needs fragmentation of foreign body before removal Small size of aspirating channel

Fiberoptic Bronchoscopy : 

Fiberoptic Bronchoscopy

Bronchoscopy - Problems : 

Bronchoscopy - Problems Competition between bronchoscopist and anesthesiologist for airway control Airway reactivity and haemodynamic responses Emergency procedure in an unprepared, poorly assessed patients with impaired respiratory function Compromised ventilation and gas exchange

Physiological changes : 

Physiological changes Increase in sympathetic activity – tachycardia, hypertension Changes in cardiac rhythm Decline in PO2 ( average 20mmHg) without significant rise in PCO2 during FOB FVC and FEV1 decreases by 13 to 30% during FOB Increase in airway resistance

Anaesthetic Technique : 

Anaesthetic Technique Choice of anaesthetic technique depends on Patient’s pre operative condition and preferences Indications for procedure Anticipated duration Anaesthesiologist familiarity

Pre Operative Evaluation : 

Pre Operative Evaluation Detailed History Problems of oxygenation and ventilation Conditions associated with increased risk of pulmonary complications Assessment of neck and jaw mobility Presence of wheeze, rales, rhonchi, stridor Prepare the patient for thoracotomy

Anaesthetic Technique : 

Anaesthetic Technique Premedication Depends on physical status of the patient, surgical technique Narcotics - For analgesia, Decreases cough reflex, Provide euphoria Anti Cholinergics Benzodiazepines Steroids

Anesthetic requirements : 

Anesthetic requirements To provide anaesthesia & analgesia Sufficient relaxation Abolition of reflexes from respiratory tract Maintenance of adequate gas exchange Rapid recovery of – consciousness, respiratory drive, cough reflex

Techniques of anaesthesia : 

Techniques of anaesthesia Regional anaesthesia – Airway block General anaesthesia - Deep inhalational anaesthesia - TIVA - Inhalational & Intravenous agents ± NMBA - LMA

Ventilation during Rigid Bronchoscopy : 

Ventilation during Rigid Bronchoscopy Spontaneous ventilation Positive pressure ventilation with oxygen delivered through side port, with open end occluded Apneic oxygenation

Special types - Ventilation during Rigid Bronchoscopy : 

Special types - Ventilation during Rigid Bronchoscopy Venturi ventilation High Frequency Jet Ventilation

Apneic Oxygenation : 

Apneic Oxygenation Denitrogenation with 100% oxygen Induction of general anaesthesia Relaxation with Neuromuscular blockers Oxygen delivery continuously in to trachea at 10 to 15ml/min Problems PCO2 level rises continuously – first minute 6 mm of Hg /min; then 3 mm of Hg/min Awareness occurs more commonly

Ventilating Bronchoscope : 

Ventilating Bronchoscope Anaesthesia circuit is attached directly to the side port of bronchoscope Glass window is placed over proximal end to occlude the lumen

Ventilating Rigid bronchoscope : 

Ventilating Rigid bronchoscope

Ventilating Bronchoscope : 

Ventilating Bronchoscope Advantages Allows both inhalational and intravenous anaesthesia Scavenging is easy Leak around bronchoscope is managed by applying manual pressure over larynx or by a inflatable cuff or throat packing

Ventilating Bronchoscope : 

Ventilating Bronchoscope ETCO2, Respirometer can be connected Pulse Oximetry is mandatory Feel of reservoir bag and Peak Inspiratory pressure will predict the lung compliance Disadvantage Pollution of OR when occluding window is opened for suction and specimen removal

Ventilating Bronchoscope : 

Ventilating Bronchoscope Recent advances Hopkins Lens Telescope Has special side ports for suction catheter, biopsy specimen

Sanders Ventilation : 

Sanders Ventilation High pressure oxygen ( 50 psi ) is intermittently jetted through a 16G cannula attached to proximal end of bronchoscope Bernoulli’s law Velocity of a fluid flowing through a pipe is inversely proportional to cross sectional area When fluid is forced to flow through a constriction, speed increases but lateral wall pressure decreases

Sander Venturi technique : 

Sander Venturi technique “By passing a high pressure gas through a narrow orifice, there is marked decrease in pressure surrounding this injector which entrains surrounding gas and markedly increases total flow”

Problems of Sanders technique : 

Problems of Sanders technique Lowering of FiO2 to 30% Inadequate ventilation due to decreased lung compliance Maximum pressure generated is 22cm H2O

Problems of Sanders technique : 

Problems of Sanders technique Best indicator of adequate ventilation is chest movement with inflation Hazard of venturi technique is Passive Exhalation which occurs through scope or tube

Modifications : 

Modifications Cardin modification Side arm of bronchoscope is in injector site Airway pressure up to 55cm H2O with driving pressure of only 30psi Other modifications Insertion Chest tube or NGT into trachea and providing Jet Ventilation Nitrous oxide with Oxygen can be used

High Frequency Jet Ventilation : 

High Frequency Jet Ventilation Beneficial in cases of Broncho pleural fistula No air entrainment occurs through proximal end of bronchoscope

Other Techniques : 

Other Techniques Placing small ETT along side bronchoscope ETT should be large enough to allow for passive exhalation Not advisable in case of tracheal narrowing or external compression

Fiberoptic Bronchoscope : 

Fiberoptic Bronchoscope Occupies only 10% of cross sectional area of trachea Awake patients can ventilate easily around scope Can be done under local or general anaesthesia For general anaesthesia, bronchoscope is introduced through ETT

FOB : 

FOB Topical or Local anaesthesia Topicalization of pharynx and tracheo bronchial tree by inhaled, nebulized lidocaine 4 to 6ml of 4% lidocaine is used Problems Area immediately below vocal cord spared Amount of absorption unknown

Local anaesthesia – Airway block : 

Local anaesthesia – Airway block

Anaesthesia for FOB : 

Anaesthesia for FOB Intravenous agents – Intermittent or Continuous infusion Inhalational agents – passing FOB through patient’s ETT; Jet ventilation with Oxygen via catheter placed per orally into trachea Oxygen via suction channel Combined topicalization with general anaesthesia is the best technique

For Rigid Bronchoscope : 

For Rigid Bronchoscope General anaesthesia is most commonly employed Induction with barbiturate or Non barbiturates Short acting opioids Neuromuscular blockade ? intubation Inhalational agent – Halothane vs Sevoflurane Intravenous agents with relaxation ? ventilation by apneic oxygenation Needs adequate plane of anaesthesia

Drugs : 

Drugs Short acting anesthetic agents Vagolytics/ antisialogogue Drugs to blunt adrenergic response Drugs to control BP and Heart rate during airway instrumentation Steroids

Bronchoscopy in ICU - Problems : 

Bronchoscopy in ICU - Problems Patient related Decreased or absent pulmonary reserve Mechanically ventilated for significant period Haemodynamic instability Co morbidities Procedure related Increase in airway resistance, peak airway pressure, PEEP Reduction in TV ? Hypercarbia, Hypoxaemia

Bronchoscopy in ICU - Measures : 

Bronchoscopy in ICU - Measures ETT size should be adequate Hand ventilation with non rebreathing circuit with 100% O2 Intermittent suctioning only Sedation according to patient status Mechanichal PEEP to be removed Monitoring ? cardiovascular status & Oxygen saturation Serial ABG analyses

Complications : 

Complications Complications associated with anaesthesia Hypoxemia , Hypoventilation Hypertension, hypotension, tachycardia, myocardial ischaemia Arrhythmias related to hypoxia and hypercarbia Toxic reaction to local anaesthetics Auditory awareness

Complications : 

Complications Complications arising from procedure Pneumothorax Severe hemorrhage Laceration of bronchial wall Laryngospasm Bronchospasm

Messages : 

Messages Bronchoscopy is highly stimulating procedure Adequate plane of anaesthesia needed till end of procedure Rapid emergence and recovery of protective airway reflexes are desirable Short acting drugs like Propofol, Rocuronium, Fentanyl, Remifentanil, Sevoflurane can facilitate these goals

Slide 55: 

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