Section I. Endotracheal intubation
I. Indications
1, general anesthesia.
2, cardiopulmonary resuscitation.
3, mechanical ventilation.
4, neonatal asphyxia, etc.
5, tracheal collapse.
6, benign airway obstruction.
Second, contraindications
1, laryngeal edema, acute inflammation of the airway, submucosal hematoma of the larynx, unless emergency tracheal intubation is strictly prohibited; severe tracheal malformation or displacement, tracheal intubation should be carefully to avoid laryngeal and tracheal injury caused by repeated trial intubation.
2, thoracic aortic aneurysm compression of the trachea, intubation may cause aneurysm rupture and bleeding, if intubation is needed, gentle and skilled movements to avoid choking, coughing, struggling caused by accidents.
3.Tranasal tracheal intubation is forbidden in cases of nasal tract opacification, nasopharyngeal fibrovascular tumor, nasal polyps or recurrent epistaxis.
4, the basic knowledge and skills of intubation are not mastered, and imperfect equipment is listed as a relative contraindication.
C. Pre-intubation preparation
1.Preoperative examination and estimation
(1) head and neck mobility: normal head and neck extension and flexion range 165-90 °, if the head is tilted back less than 80 ° can make intubation difficult, see the neck pathology (rheumatoid arthritis, etc.), excessive obesity (neck thick and short high larynx, etc.) or congenital diseases (oblique neck, etc.).
(2) Mouth and teeth: normal mouth opening can reach 4-5 cm, if the mouth opening is less than 2.5 cm, it often prevents laryngoscope placement, which is seen in temporomandibular joint lesions; maxillofacial scar contracture; maxillofacial, tongue or intraoral tumors and congenital diseases (giant tongue, micrognathia, etc.). If there is a movable denture, all of it should be removed before anesthesia.
(3) The proposed nasal intubation should be understood when the nasal cavity is open, whether there is a history of nasal injury, nasopharyngeal surgery, whether there are tonsillar enlargement in the pharynx, abscesses in the posterior pharyngeal wall, etc.
(4) The presence of tracheal stenosis should be fully understood before surgery. Huge tumors in the neck, aortic aneurysms and other long-term compression of the trachea often soften the tracheal cartilage ring and narrow the lumen, or the trachea may be narrowed after trauma.
(5) For those who have pharyngeal lesions (tumor, edema, stenosis, etc.) that may block the intubation path and prevent tracheal intubation through the voice box, consideration should be given to post-tracheostomy intubation.
2.Check the anesthesia machine and oxygen supply conditions
(1) Whether the oxygen supply equipment (central oxygen supply or oxygen cylinder) is free of obstruction and can adequately supply oxygen.
(2) Whether sodium lime has failed.
(3) whether the anesthesia machine and circuit have air leakage.
(4) whether the anesthesia mask is suitable
(5) whether the suction device and suction tube are fully prepared.
3.Preparation of intubation equipment
(1) Laryngoscope: pay attention to the size of the lens, power contact and brightness.
(2) Tracheal catheter and core: choose the catheter of appropriate diameter and have one catheter larger and one smaller than the catheter of choice. General adults with F32 ~ 38, or 7 ~ 8.5 inner diameter catheter. For pediatric tracheal tube selection, see the pediatric anesthesia routine.
(3) nebulizer: the name and concentration of the local anesthetic should be indicated.
(4) dental pads, articulating tubes, intubation forceps, etc.
IV. Commonly used endotracheal intubation methods
1, transoral visual intubation
(1) The patient’s head is tilted back to increase the angle of the transoral and transglottic axes to facilitate the exposure of the vocal cords, but excessive tilting back should be avoided in pediatric intubation.
(2) The laryngoscope should be placed on the right side of the mouth (between the right edge of the tongue and the cheek). When the laryngoscope is moved to the middle of the mouth, the tongue is automatically pushed to the left side so as not to obstruct the view and operation of intubation.
(3) The uvula is first seen and then the lens is advanced vertically until the epiglottis is seen.
(4) Pick up the epiglottis to reveal the acoustic canal. If a straight lens is used, it can be reached to the acoustic door side of the epiglottis, and then the stem is lifted forward and upward to reveal it. If the curved lens is used, the lens will be placed at the junction of the lingual root of the epiglottis (epiglottis valley) and lifted forward and upward with force, so that the ligament of the epiglottis is tense and the epiglottis is raised against the laryngeal lens, and the vocal fold can be revealed.
(5) When inserting the tube, hold the upper middle section of the catheter with the right thumb, index finger and middle finger like a pencil, enter the mouth from the right side until the catheter is close to the larynx, then move the end of the tube to the laryngeal lens, while monitoring the direction of the catheter through the narrow gap between the lens and the tube wall with both eyes, and insert the tip of the catheter into the voice box accurately and deftly.
(6) When intubating with the help of the core, after the tip of the catheter is inserted into the voice box, the assistant can be made to pull it out carefully, while the operator must hold the catheter in the direction of the voice box to prevent the catheter from being pulled out, and after the core is pulled out, the catheter is immediately inserted into the trachea in a homeopathic manner, and the depth of insertion into the trachea is 4 to 5 cm for adults.
(7) By looking, measuring and listening to the three elements to decide and adjust the depth of catheter insertion, and finally to be fixed and listened to again.
2.Tranasal bright vision intubation
(1) Select a larger nostril and insert 1~3% ephedrine drops to make the nasal mucosa vasoconstriction, increase the volume of nasal cavity, and reduce bleeding.
(2) After induction of anesthesia, the nasal cavity is first tested with a cotton swab dipped in lubricant to remove as much nasal dirt as possible, and then a tracheal tube coated with lubricant is inserted through the nose, which is slightly thinner than the oral cannula and oriented perpendicular to the face, and the laryngoscope is used to reveal the voice box when the tube enters the pharynx through the posterior nostril.
(3) The method and essentials of revealing the voice box with the laryngoscope are the same as those for transoral visual intubation.
(4) After revealing the vocal hilum, the left hand firmly holds the handle of the scope while the right hand continues to advance the catheter toward the vocal hilum. When the catheter reaches above the epiglottis, the direction of the catheter tip is changed by changing the head position or rotating the catheter to reach the vocal hilum, or the catheter can be delivered into the vocal hilum by clamping the front end of the catheter through the oral cavity using a cannula. After success, the catheter can be fixed directly to the patient’s nasal face with adhesive tape.
(5) Judgment of the depth of intubation is the same as transoral visual intubation.
3.Blind transnasal intubation
(1) First, use ephedrine drops to make local vasoconstriction, and use a sprayer to spray surface anesthetic into both nostrils when the patient inhales, once every 1~2 min for a total of 3~4 times, about 1 ml. then inject 1% dicaine or 2% lidocaine 1~2 ml into the cricothyroid membrane puncture, and start intubation after 1~2 min of perfect anesthesia.
(2) The patient lies supine with the head tilted back as far as possible and the nostrils facing upward. The right hand holds the catheter coated with slip and the face in a perpendicular direction and inserts it into the nostrils, exiting the posterior nostril along the base of the nose to the pharyngeal cavity.
(3) Hold the patient’s occiput with the left hand, hold the catheter in the right hand, listen to the breath sounds with the ear, and judge the position and distance between the oblique end of the catheter and the voice box based on the strength of the breath flow sound inside the catheter. The catheter constantly exhales gas to indicate the correct direction of intubation, and when the patient’s inspiratory voice gate opens wide, the catheter is slowly pushed into the voice gate, i.e., there is a breath-holding cough or a strong breath sound in the catheter. If the airflow is interrupted, the catheter should be withdrawn to adjust the head position or press the laryngeal node with the left hand and then reinserted.
(4) If the catheter is blocked from advancing, the catheter may be biased to both sides of the larynx, and the neck needs to be slightly flexed forward before reinsertion.
(5) If the catheter can be advanced, but the exhaled airflow disappears, it is a manifestation of insertion into the esophagus. The catheter should be retired to the nasopharynx, and the head should be tilted slightly so that the tip of the catheter is cocked upward, or can be aligned with the vocal cords to facilitate insertion.
(6) Sometimes the nasal cannula fails to be inserted through one side, it may be inserted smoothly by the other side.
(7) Such as the use of shallow anesthesia under intubation, must retain sufficient tidal volume, based on the exhaled airflow to determine the position of the front end of the catheter aligned with the vocal cords, before induction ephedrine nasal drip.
V. Handling of difficult tracheal intubation
1, blind intubation through the nasal cavity: the oral cavity can not reveal the larynx resulting in intubation difficulties, can be changed to blind intubation through the nasal cavity. After repeated intubation still slipped into the esophagus, can first retain a catheter in the esophagus, and then intubate through the other nostril, can often be successful. The success rate can be improved by applying a special shaped nasal endotracheal tube.
2, the application of adjustable laryngeal lens (such as McCOY laryngeal lens), when placed under the epiglottis, can be made from the handle of the mirror to make the tip cocked, easy to reveal the voice
The laryngeal lens (e.g., McCOY laryngeal lens) can be placed under the epiglottis with the tip tilted up from the stem to reveal the vocal fold. Using a tracheal tube with a guiding device, the position of the front end can be adjusted during insertion to improve the success rate of intubation.
3.Intubation by fiberoptic laryngoscope or fiberoptic bronchoscope: Put the tracheal tube outside the mirror rod, and then insert the fiberoptic laryngoscope or fiberoptic bronchoscope according to the endoscopic operation principle.
The laryngoscope or fiberoptic bronchoscope is fed into the voice box according to the endoscopic operation principle, and then the tracheal tube is fed into the trachea along the mirror rod.
4.Transcircumferential cricothyroidal puncture with guide wire intubation method
(1) Insert the guidewire (CVP guidewire or epidural catheter) retrogradely through the cricothyroid membrane into the oropharynx and pull out one end.
(2) Place the tracheal catheter outside the guidewire, hold both ends of the wire, send the tracheal catheter along the wire through the vocal canal to the trachea, then pull out the guidewire (pay attention to fix the tracheal catheter when pulling out), and then push the tracheal catheter forward by 2-3 cm.
(3) The tracheal tube is easily obstructed in the epiglottis when placed along the wire and needs to be adjusted repeatedly. The operation should be gentle to avoid tissue damage.
(4) Apply the tip with a light source malleable catheter core, insert the core into and over the tracheal tube, and use the plasticity of the core and the light point seen from the neck to guide the direction of intubation during the intubation process.
VI. Precautions
1.The choice of tracheal tube should be decided according to the patient’s age, gender and size.
2.The larynx should be well exposed during intubation, with a clear view and gentle operation to prevent injury.
3.After the catheter is inserted into the trachea, the respiratory sounds of both lungs should be checked for normalness to prevent accidental entry into the bronchi, and then the catheter should be fixed to prevent slippage, and the endotracheal secretions should be suctioned at the same time with a view to checking whether the catheter is unobstructed and has no distortion.
4.Anaesthesia period should be closely observed breathing, check the effect of sodium lime to prevent carbon dioxide accumulation, domestic sodium lime can generally be used 8h/1000g, if not exceeded should be sealed, and indicate the time to be used next time.
5, the tracheal tube sleeve inflation should be moderate, its internal pressure is generally not higher than 4kPa (30mmHg) long stay, need 4-6h for a short period of deflation.
Section II endobronchial intubation
I. Indications
(1) Bronchopleural fistula and bronchial rupture.
(2) Wet lung, active pulmonary hemorrhage, bronchiectasis, etc.
(3) Transbronchial lung lavage.
(4) Facilitation of surgery after collapse of one lung, such as esophagectomy (relative indications).
(5) Unilateral lung infection, abscess and occupying lesions.
II. Methods
1.Double-lumen bronchial intubation
The characteristics of the double-lumen tube can temporarily separate the ventilation of the left and right bronchus, so that both the healthy side of the lumen can be ventilated, and the anesthesia and ventilation can be performed bilaterally at the same time, and the secretions can be aspirated separately, increasing the safety in anesthesia. There are two types of double-lumen tubes: a left (Calens) and right (White) double-lumen tube with a rongeur hook and two capsules in the left and right lumens, and a double-lumen tube with two capsules in the left and right lumens without a rongeur hook (i.e., Robertshaw), with three sizes of F35, 37 and 39. The operation method is basically the same as tracheal intubation or single-lumen bronchial intubation, with the following differences.
(1) The catheter needs to be well slipped, with the head position tilted back as far as possible, and both straight and curved laryngeal lenses can be used.
(2) The position of the catheter before it enters the voice box (Carlens double-lumen tube as an example) should be that the left tube oblique mouth points to the epiglottis and the rongeur hook points to the posterior pharyngeal wall; after the left tube end is inserted into the voice box, the catheter is rotated 180° counterclockwise so that the rongeur hook turns to the front of the voice box and slides into the trachea; the rongeur hook points to the left and right bronchi respectively, and the catheter continues to be advanced until resistance is encountered, suggesting that the rongeur hook has ridden across the rongeur and the left tube has entered the main bronchi. The tube has entered the main bronchus.
(3) After the balloon is inflated and auscultated, one side of the luminal tract is clamped separately to determine the position of the catheter and fix it. After placement, the catheter is then auscultated again to ensure that the catheter position is correct.
(4) The catheter without bulging hooks can easily pass through the voice box, and the catheter position is determined according to the depth and auscultation.
2.Single-lumen endobronchial tube
A single-lumen bronchial tube is inserted into the main bronchus of the healthy side for unilateral lung ventilation, which is suitable for unilateral pneumonectomy. The operation method is basically the same as that of endotracheal intubation, but it should be noted that
(1) The breath sounds of both lungs must be auscultated before intubation to facilitate identification and control after intubation.
(2) The single-lumen bronchus needs to be longer (32-36 cm) than the tracheal tube, with a thin diameter (F24-30) and a flexible and elastic texture.
(3) After the catheter enters the voice box with the bevel facing the side ready for insertion, so that the catheter can be pushed in against the wall of that side of the trachea, generally easier to the right main bronchus, such as to the left bronchus when there is difficulty in intubation, it is estimated that when the catheter is close to the bulge, the catheter will be slightly rotated in the counterclockwise direction and the patient’s head will be turned to the left side for further advancement.
(4) Immediately after intubation, inflate the balloon, listen to the breath sounds on both sides of the lungs to determine the position of the catheter, and fix it properly after it is correct.
(5) Thereafter, the patient should be auscultated after a change in position, choking or moving the head and neck of the body to prevent catheter dislodgement or displacement.
(6) When the stump of the bronchus on the sick side is sutured, the catheter can be retired to the trachea while suctioning to reduce the irritation of the rongeur.
Caution
1.When intubating, pay attention to good exposure of the vocal hilum, and prohibit violence to insert the rongeur hook into the vocal hilum to cause injury.
2. The catheter must be correctly positioned and firmly fixed after intubation to avoid intraoperative catheter slippage from the bronchus.
3.The lumen of the double-lumen tube is narrow, and the resistance of the airway increases. Reasonable use of assisted breathing or controlled breathing is used intraoperatively to ensure gas exchange and prevent carbon dioxide accumulation.
4. Do not insert the single-lumen bronchial tube too deeply, especially into the right bronchus, to prevent obstruction of the bronchial opening in the upper lobe of the lung.
5, intraoperative secretions should be removed in a timely manner.
6.When using the left double-lumen tube for total pneumonectomy, before cutting the left common bronchus, the catheter should be withdrawn into the common trachea to avoid cutting off the left branch of the catheter.
7. Pay attention to prevent complications and accidents during intubation and extubation. In particular, accidental entry of the tracheal tube into the esophagus, hypertension and tachycardia, accidental vomiting and aspiration during extubation, tracheal atrophy and asphyxia, cardiac arrest during extubation.