management（气道管理） ppt课件

Airway Management,Importance,The major responsibility of the anesthesiologist is to provide adequate respiration for the patient. The most vital element in providing functional respiration is the airway. No anesthetic is safe unless diligent efforts are devoted to maintaining an intact functional airway. The same principles of airway management outlined in this chapter are applicable to all clinical situations in which respiratory inadequacy may develop.,The First Section Maintenance of Airway Smooth,1. Stucture And Function Of The Airways,Upper Airways: Mouth, nose, pharynx, larynx Lower Airway: Trachea, Bronchus ,Lung,Nose,The nose is the primary pathway for normal breathing unless obstruction by polyps or upper respiratory infection is present. During quiet breathing, the resistance to airflow through the nasal passages accounts for almost two thirds of the total airway resistance. The resistance through the nose is almost twice that associated with mouth breathing.,Pharynx,The pharyngeal airway extends from the posterior aspect of the nose down to the cricoid cartilage, where the passage continues as the esophagus.,larynx,The larynx, which lies at the level of the third through sixth cervical vertebrae The laryngeal cavity extends from the epiglottis to the lower level of the cricoid cartilage. The glottis represents the narrowest point in the adult airway (more than 8 years of age), whereas the cricoid cartilage represents the narrowest point in the infant airway (birth to 1 year of age).,Trachea,The trachea is a fibromuscular tube that is 10 to15cm long with a diameter of approximately 20 mm in adults. It extends from the cricoid cartilage to the carina. The trachea bifurcates into the right and left main stem bronchi at the carina. The right main stem bronchus is approximately 2.5 cm long with a take-off angle of approximately 25. The left main stem bronchus is approximately 5 cm long with a take-off angle of approximately 45.,2. Reason and Treatment of Airway Obstruction,Reason of Airway Obstruction: Secretions ,blood, foreign body block airway. Glossocoma Laryngospasm Bronchospasm Neuromuscular disease,Glossocoma,Glossocoma is the most common reason of upper airway obstruction. Symptoms and Signs In less severe cases: Snore ,the throat was dragged. In severe cases:Abnormal chest breathing, three depressions sign during inspiration. SPO2 decrease, Cyanosis Treatment jaw thrust, nasopharyngeal airway or oropharyngeal airway.,Laryngospasm,Definition Laryngospasm consists of prolonged intense glottic closure in response to direct glottic or supraglottic stimulation from inhaled agents,secretions, or foreign bodies. Symptoms and Signs In less severe cases: a high-pitched squeaky sound or stridor(喘鸣). In severe cases: total absence of sound, obstructed pattern of breathing , the anesthetist will not be able to ventilate the patient. The hypoxia, hypercarbia, and acidosis will develop, Hypotension, bradycardia, and ventricular dysrhythmias leading to cardiac arrest will ensue unless airway patency is restored within minutes.,Treatment When laryngospasm is less severe: Deepening the anesthetic level and removing the stimulus while administering 100% oxygen . Moderate spasm: continuous positive pressure on the airway with mask and a jaw thrust may relieve the spasm. severe spasm : use of muscle relaxants such as succinylcholine（琥珀胆碱）, endotracheal intubation if necessary . The lungs should be ventilated with 100% oxygen, and either the anesthetic level should be deepened before the noxious stimulation is resumed or the patient may be allowed to awaken if laryngospasm has occurred during emergence,Laryngospasm,Laryngospasm,Incentives most commonly caused by an irritative stimulus to the airway during a light plane of anesthesia Others include secretions, vomitus, blood, inhalation of pungent（辛辣的） volatile（挥发性的） anesthetics, oropharyngeal or nasopharyngeal airway placement, laryngoscopy, painful peripheral stimuli, and peritoneal traction during light anesthesia.,Bronchospasm,Incentives anaphylactoid drug and blood transfusion reactions , secretions and endotracheal intubation Symptoms and Signs Wheezing (usually more pronounced on expiration) tachypnea and dyspnea in the awake patient. difficult to ventilate in the anesthetized patient,3.The Basic Way to Establish an Effective Airway,Basic rule: simple, effective, safe and familiar . Maintain the anatomy airway: Head-down position or Lateral position ;suction ;jaw thrust; nasal or oral airway. Establish the artificial airway: Mask ,laryngeal mask, trachea .,The Second Section Technologies of Airway Management,Methods of Airway Management,Orapharyngeal airway Nasopharyngeal airway Mask ventilation Laryngeal mask airway Endotracheal intubation,1. Orapharyngeal airway,Indications Jaw thrust is invalid for upper airway obstruction. Glossocoma of coma patients or sedative patients Complications Nausea or vomiting ,coughing, laryngosasm, bronchospasm, and dental trauma. The wrong size oral airway may worsen obstruction. If too short, it may compress the tongue; if too long, it may lie against the epiglottis.,Oropharyngeal Airway (Berman intubation airway),2. Nasopharygeal Airway,Indications The same as the oropharyngeal airway Advantages Better tolerated by awake or sedated patients Less cause nausea or vomiting ,coughing, laryngosasm, bronchospasm Especially good for restricted openning,Contraindications Abnormal clotting mechanism Fracture in the skull base Nasopharyngeal cavity infection Nasal septum shift,Nasopharygeal Airway,Nasopharygeal Airway,Intubating nasal airway,3. Mask Ventilation,Indications To provide inhalation anesthesia in patients not at risk for regurgitation of gastric contents. To preoxygenate (denitrogenate) a patient before endotracheal intubation. To assist or control ventilation as part of initial resuscitation.,Technique involves placing a face mask and maintaining a patent airway. The mask should fit snugly around the bridge of the nose, cheeks, and mouth. Clear plastic masks allow for observation of the lips (for color) and mouth (for secretions or vomitus). Mask placement. The mask is held in the left hand so that the little finger is at the angle of the mandible, the third and fourth fingers are along the mandible, and the index finger and thumb are placed on the mask. The right hand is available to control the reservoir bag. Two hands may be required to maintain a good mask fit, necessitating an assistant to control the bag. Head straps may be used to assist mask fit.,Mask Ventilation,Airway patency may be restored by the following: Neck extension. Jaw thrust, by placing the fingers under the angles of the mandible and lifting forward. Turning the head to one side. Insertion of an oral airway or a nasal airway,Mask Ventilation,Mask Ventilation,Intubating Mask,Complications. The mask may cause pressure injuries to soft tissues around the mouth, mandible, eyes, or nose. Mask ventilation does not protect the airway from aspiration of gastric contents.,Mask Ventilation,4. Laryngeal Mask Airway (LMA),Classic LMA,Special LMA,Intubating LMA,Gastric LMA,Standard Insertion Technique,LMA,Position When inserted appropriately, the LMA lies with its tip resting over the upper esophageal sphincter, cuff sides lying over the pyriform fossae, and cuff upper border resting against the base of the tongue. Such positioning allows for effective ventilation with minimal inflation of the stomach.,Failure of LMA Insertion,Indications As an alternative to mask ventilation or endotracheal intubation for airway management in patients without risk of aspiration of gastric contents (The LMA is not a replacement for endotracheal intubation when endotracheal intubation is indicated). In the management of a known or unexpected difficult airway. In airway management during the resuscitation of an unconscious patient.,LMA,LMA,Contraindications Patients at risk of aspiration of gastric contents (emergency use is an exception). Patients with mouth opening less than 2.5-3.0cm. Patients with infection, injury,hemangioma in the throat Patients with decreased respiratory system compliance, peak inspiratory pressures should be maintained more than 25 cm H2O Patients in whom long-term mechanical ventilatory support is anticipated or required. Patients with intact upper airway reflexes, because insertion can precipitate laryngospasm.,LMA,Adverse effects. The most common adverse effect is sore throat The primary major adverse effect is aspiration. Laryngeal edema ,uncommon,5. Tracheal Intubation,Occording to the position of tube: Endotracheal Intubation Endobronchial intubation Occording to pathway : Nasotracheal intubation Orotracheal intubation Occording to the glottis exposure : Photopic intubation Blind intubation Occording to the anesthetic methods: Slow induction intubation Fast induction intubation Awake induction intubation,Indications. patients are at risk for aspiration; airway maintenance by mask is difficult; prolonged controlled ventilation. specific surgical procedures (e.g., head/neck, intrathoracic, or intra-abdominal procedures).,Endotracheal Intubation,Endotracheal Intubation,Technique. Intubation is usually performed with a laryngoscope. The Macintosh and Miller blades are most commonly used. Many specially modified laryngoscopes are available under difficult or unusual conditions The patient should be positioned in the so-called sniffing position. An appropriate ETT size depends on the patients age, body habitus, and type of surgery,Endotracheal Intubation,Complications of orotracheal intubation Injury: include injury of the lips or tongue, teeth, pharynx, or tracheal mucosa. There may rarely be avulsion of arytenoid cartilages or damage to vocal cords or trachea. Endotracheal tube is not smooth Excessive sputum Tube is too deep to block bronchus Anesthesia machine faults,Nasotracheal intubation,Indications: Nasotracheal intubation may be required in patients undergoing an intraoral procedure. Contraindications: Basilar skull fractures, especially of the ethmoid bone, nasal fractures, epistaxis, nasal polyps, coagulopathy, and planned systemic anticoagulation and/or thrombolysis,Complications : Similar to those described for orotracheal intubation. Additionally, epistaxis, submucosal dissection, and dislodgement of enlarged tonsils and adenoids may occur. Sinusitis and bacteremia.,Nasotracheal Intubation,Endobronchial intubation,Endobronchial intubation,The Third Section Difficult Airway,Difficult Airway,Definition : The formal training anesthesiologist or doctors in emergency and ICU fail to ventilate patients by mask or intubate patients with conventional laryngoscopy . The ASA defines a difficult airway as failure to intubate with conventional laryngoscopy after three attempts and/or failure to intubate with conventional laryngoscopy for more than 10 min.,Difficult Airway,Categories : The difficult airway can be divided into the recognized difficult airway and the unrecognized difficult airway the latter presents the greater challenge for the anesthesiologist.,Evaluation of Difficult Airway,History: A history of difficult airway management ; Arthritis or cervical disk disease ; Infections of the floor of the mouth ; a history of obstructive sleep apnea ; Tumors or trauma associated with airway; Previous surgery, radiation, or burns ; Scleroderma ; Trisomy 21 patients; Dwarfism,Evaluation of Difficult Airway,Physical examination : Specific findings that may indicate a difficult airway include the following: Inability to open the mouth(1.5cm) Poor cervical spine mobility. thyromental distance is less than 6 cm Receding chin (micrognathia). Large tongue (macroglossia). Prominent incisors. Short muscular neck. Morbid obesity,Evaluation of Difficult Airway,Mallampati classification :Assessment is made with the patient sitting upright, with the head in the neutral position, the mouth open as wide as possible, and the tongue protruded maximally. The modified classification includes the following four categories :,Evaluation of Difficult Airway,The modified Mallampati classification includes the following four categories : Class I. Faucial pillars, soft palate, and uvula are visible. Class II. Faucial pillars and soft palate may be seen, but the uvula is masked by the base of the tongue. Class III. Only soft palate is visible. Intubation is predicted to be difficult. Class IV. Soft palate is not visible. Intubation is predicted to be difficult.,Evaluati