See PODCAST 4 at emcrit.org
altering the gag reflex with pressure on the palm (Altering the Gag Reflex Via a Palm Pressure Point (JADA October 1, 2008 139(10): 1365)
Antisalagogue (Choose 1)
· Glycopyrolate 0.2 mg IV (actual dose 0.01 mg/kg, may need doses of 0.4-0.8 mg in larger patients)
Glycopyrrolate, like other anticholinergic (antimuscarinic) agents, inhibits the action of acetylcholine on structures innervated by postganglionic cholinergic nerves and on smooth muscles that respond to acetylcholine but lack cholinergic innervation. These peripheral cholinergic receptors are present in the autonomic effector cells of smooth muscle, cardiac muscle, the sinoatrial node, the atrioventricular node, exocrine glands and, to a limited degree, in the autonomic ganglia. Thus, it diminishes the volume and free acidity of gastric secretions and controls excessive pharyngeal, tracheal, and bronchial secretions. Glycopyrrolate antagonizes muscarinic symptoms (e.g., bronchorrhea, bronchospasm, bradycardia, and intestinal hypermotility) induced by cholinergic drugs such as the anticholinesterases. The highly polar quaternary ammonium group of Glycopyrrolate limits its passage across lipid membranes, such as the blood-brain barrier, in contrast to atropine sulfate and scopolamine hydrobromide, which are highly non-polar tertiary amines which penetrate lipid barriers easily. With intravenous injection, the onset of action is generally evident within one minute. Following intramuscular administration, the onset of action is noted in 15 to 30 minutes, with peak effects occurring within approximately 30 to 45 minutes. The vagal blocking effects persist for 2 to 3 hours and the antisialagogue effects persist up to 7 hours, periods longer than for atropine.
Atropine .01 mg/kg IV
(Choose 1 of the 4)
· 5 cc 2% lidocaine and 5cc 2% Lidocaine with 1:100,000 Epi nebulized
· Lidocaine 4% 5cc nebulized (minimal systemic absorption when using nebulizers [Chest 1977;71(3):346])
· 4cc of 4% Lidocaine and 1 cc of 0.5-1% Neosynephrine nebulized (alternative 3 cc of 4% and 3 cc of NS)
· Lidocaine/Hurricaine spray (if no time for nebs) or use mucosal atomization device to spray 4% Lidocaine in oropharynx
Anesthetize Lower Airways
· Translaryngeal injection of 2-4 cc 4% lidocaine
· Soak pledgets in 4% lidocaine and leave in nose for 5 minutes and/or spray c 2% neo-synephrine. Or use 4% cocaine (max 1-3 mg/kg) or Lidocaine with 1:25,000 epinephrine
Sedate (Choose 1)
· Versed 2-4 mg (takes 3-5 minutes for effect)
· 50% Ketamine and 50% Propofol in a syringe (5 cc of each) Give in small aliquots. Ketamine alone, give 1/5 dose intubating dose, wait and repeat if necessary (Volume 92(6) June 2001 pp 1465-1469 The Effects of Small-Dose Ketamine on Propofol Sedation: Respiration, Postoperative Mood, Perception, Cognition, and Pain)
- Consider Scopolamine
Best choice these days is probably precedex (One series Dexmedetomidine and Awake Fiberoptic Intubation for Possible Cervical Spine Myelopathy: A Clinical Series. Journal of Neurosurgical Anesthesiology. 17(2):97-99, April 2005.) also now (Can J Anesth 2005; :776 Dexmedetomidine is a useful adjunct for awake intubation) Also J Clinical Anesthesia 2007;In Press by Abdelmalak B.)
1 mcg/kg over 10 minutes then 1 mcg/kg/hour, lower down to 0.7 when you have effect
redistributes in ~ 6 hours
kidney and hepatic elimination
Another Dexmedetomidine Study (Anaesthesia 2010,65:254) they just used the bolus
Placing the tube is even more physiologically invasive than laryngoscopy. Consider taking quick look and if the cords are easily visualized in a non-dynamic situation, consider RSI at that point, otherwise just pass the tube.
2% viscous for swishing through mouth, coat nasal trumpet
5% ointment place on back of tongue and oropharynx with tongue blade
Pacey’s paste-make slurry by combining 2% viscous with 4% using 3 way stopcock to mix
can add sweet & low to make more palatable
Can use nasal CPAP to continue oxygenation during attempt (Chest 1994;106(1):287)
Continuous Positive Airway Pressure during Fiberoptic Bronchoscopy in Hypoxemic Patients
Maitre B. Jaber S et al.
Am J Respir Crit Care Med 162, 1063-1067, 2000
Fiberoptic bronchoscopy (FOB) may worsen oxygenation and clinical status in severely hypoxemic patients. We conducted a prospective, randomized double-blind trial to compare the delivery of continuous positive airway pressure (CPAP) as a tool for maintaining oxygenation during FOB, to the delivery of oxygen only. Thirty consecutive patients who needed FOB for diagnostic purposes were enrolled. Their arterial oxygen pressure (PaO2) to inspired oxygen fraction (FIO2) ratio was below 300 mm Hg. CPAP was generated by a simple new device open to the atmosphere. During FOB and the 30 min thereafter, pulse oximetry values (SpO2) were significantly higher in the CPAP than the Oxygen group (95.7 ± 1.9% versus 92.6 ± 3.1, p = 0.02). The lowest SpO2 values were observed in the Oxygen group (93.5 ± 2.4% versus 88.6 ± 3.4, p = 0.002). Arterial blood gases 15 min after FOB showed that PaO2 had increased in the CPAP group and decreased in the Oxygen group (PaO2 = +10.5% ± 16.9 versus 15% ± 16.6, p = 0.01). Five patients in the Oxygen group, but none in the CPAP group, developed respiratory failure in the 6 h after FOB and required ventilatory assistance (p = 0.03). We conclude that in hypoxemic patients, the use of a new CPAP device during FOB allowed minimal alterations in gas exchange and prevented subsequent respiratory failure.
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From the incredible site: http://www.pitt.edu/~regional/Airway%20Blocks/airway_blocks.htm
Of all the regional anesthesia techniques, airway blocks are the most critical and should be mastered by all anesthesia providers. These techniques are employed frequently with the diagnosis of a difficult airway, with trauma, and in emergent situations. They are usually performed on sedated, spontaneously ventilating “awake” patients requiring tracheal intubation (with need to maintain “awake” protective airway reflexes). Most situations call for a combination of these techniques as described below.
Preparation: It is recommended, that before proceeding with any of these techniques:
1. The adult patient is prepared by giving an explanation of the need for awake intubation, nasal endoscopy or other airway procedure, and will be more cooperative once they understand the rationale for any uncomfortable procedures that must be performed.
2. Preparation of the patient includes the use of antisialogogues (atropine 0.5-1 mg or glycopyrrolate 0.2 -0.4 mg IV) and the use of a vasoconstrictor for the nasal mucosa (1% phenylephrine spray) in the absence of contraindications to either. To be most effective, they should be administered 30-45 minutes prior to application of the local anesthetic (often in the holding area) to decrease the amount of secretions (essential to the use of indirect optical instruments such as the fiberoptic bronchoscope and rigid fiberoptic laryngoscope). They decrease saliva production, increase the effectiveness of topically applied local anesthetics by removing the barrier to mucosal contact, decrease drug dilution and are important to the success of these techniques.
- Medication may be given to allay anxiety. If tolerated and not contraindicated, it is extremely useful to administer small doses of benzodiazepines (ex: Midazolam 1-2 mg) IV or PO, and may be reversed if need be with specific antagonists (ex: Flumazenil).
- Small doses of Opiod receptor agonists (ex: Fentanyl or Remifentanil) can be administered to avoid the discomfort of these procedures, and for their sedative and antitussive effects. Over sedation of patient must be avoided, in that it may cause the patient to lose protective airway reflexes, obstruction of the airway, regurgitation of gastric contents or unable to cooperate with the procedure. Specific antagonists (ex: Naloxone) should be available.
General Indications for Airway Blocks:
To provide airway blocks before anesthetic induction in patients with airway compromise, trauma to the upper airway, or cervical instability.
To abolish or blunt reflexes such as laryngospasm, coughing, and other undesirable cardiovascular reflexes that often occur during procedures that involve manipulation of the airway (awake laryngoscopy, nasal intubation, and fiberoptic intubation).
To provide patient comfort and airway anesthesia during the performance of these procedures.
The following blocks are discussed:
- Anesthesia of the Nasal Mucosa and Nasopharynx (Nasal Intubation)
- SPHENOPALATINE GANGLION and ETHMOID NERVE
Anesthesia of the Mouth, Oropharynx and Base of Tongue
- GLOSSOPHARYNGEAL NERVE BLOCK
- SUPERIOR LARYNGEAL NERVE BLOCK
Anesthesia of the Hypopharynx, Larynx and Trachea
- RECURRENT LARYNGEAL NERVE BLOCK
- TRANSTRACHEAL BLOCK
Figure 1 (below): The three principal neural pathways of the airways and their related anatomy.
(click on pictures to see larger images)
Related Anatomy of Airway Blocks:
Innervation of the airway can be separated into three principal neural pathways:
Nasal/Nasopharyngeal Cavity Maxillary branches of the Trigeminal Nerve (CN V)
Indicated for Nasal Intubations or Procedures
Oropharyngeal - Glossopharyngeal Nerve (CN IX)
Indicated for manipulations involving areas above the epiglottis,
Pharynx and Posterior 1/3 of Tongue, and Laryngoscopy
Laryngeal Cavity & Trachea – Branches of the Vagus Nerve (CN X)
Indicated for blocking of structures more distal in airway to the epiglottis
*There is no single nerve that can be blocked to produce complete anesthesia of the airway.
(Left): Ophthalmic (V1), and Maxillary (V2) Nerves.
[*Note the following structures: Trigeminal nerve (V), Maxillary nerve (V2), Pterygopalatinum (Sphenopalatine) ganglion, Nasal branch of the maxillary nerve, External nasal branch of the anterior ethmoidal nerve.]
I. Anesthesia of the Nasal Mucosa and Nasopharynx
Indications: To provide anesthesia for the passage of a nasotracheal tube
To provide the initial steps for blunting of airway reflexes associated with awake nasotracheal, oropharyngeal and fiberoptic intubations.
Drugs: 4% Lidocaine with epinephrine (or cocaine is a 4% solution max. 200 mg in adult), or mixture of Lidocaine 3% and Phenylephrine 0.25% -
Anatomy: Sensation is via the middle division (V2) of the Trigeminal nerve (CN V), which lies below the nasal mucosa, posterior to the middle turbinate. Innervation to the nasal mucosa and nasal cavity involves the sphenopalatine ganglion (Meckels or pterygopalatinum ganglion) and the ethmoid nerve. Preganglionic fibers are derived from the facial nerve via the greater petrosal nerve and nerve of the pterygopalatinum canal. The postganglionic fibers supply the lacrimal, nasal and palatine glands. Sensory and sympathetic fibers pass through the ganglion).
Patient Position: Patient is most comfortable when head of bed is elevated approximately 30˚.
Technique: *Application of long cotton-tipped applicators or wide cotton pledgets soaked in the local solution (lidocaine and cocaine or phenylephrine) are applied over the nasal mucosa by inserting applicators into both nares in the following manner:
1. one applicator is placed along the inferior turbinate to the posterior nasopharyngeal wall
2. a second applicator is placed in a cephalad angulation along the middle turbinate, back to the mucosa covering the sphenoid bone (most important as it is the one most likely to anesthetize branches of the sphenopalatine ganglia as they pass along the lateral wall of the airway )
3. a third applicator may be placed along the superior turbinate, resting against the cribiform plate and posterior nasopharyngeal wall, providing anesthesia to the anterior ethmoid nerve
4. The applicators are then left in place for 5 minutes, and the pledgets for 2-3 minutes. (The use of wide cotton pledgets placed into the same areas with alligator forceps provides maximal topical anesthesia and vasoconstriction of the nasal mucosa).
Additionally, *nasal airways, in increasing sizes, can be lubricated with Lidocaine 2-5% jelly, and passed into the nostril being intubated for additional patient comfort.
*These procedures allow for blocking of the sphenopalatine (or Meckels ganglion) and the ethmoid nerve.
They should be done bilaterally provide posterior pharyngeal anesthesia, caudad to this level.
Assessment of Block Efficacy: Patient tolerates introduction of nasal airways and/or nasal intubation.
Complications: Epistaxis can occur due to trauma to nasal mucosa. Also, systemic toxicity can occur, thus doses of anesthetic delivered to the patient should be monitored to prevent exceeding the maximum dosages. Loss of protective laryngeal reflexes may place patient at increased risk for aspiration.
II. Anesthesia of the Mouth and Oropharynx
Indications: abolition of the gag reflex or hemodynamic response to laryngoscopy.
Drugs: Cetacaine spray (mix of 14% Benzocaine and 2% Tetracaine), Lidocaine spray 10%, Lidocaine gel 2-5%, Viscous lidocaine 2%, Tetracaine .5% soln, Lidocaine 4% soln.
Anatomy: Sensation of the oral mucosa and oropharynx are supplied by branches of the glossopharyngeal nerve (CN IX), vagus (CN X) and facial nerve (CN VII). The glossopharyngeal nerve travels anteriorly along the lateral surface of the pharynx, with its three branches supplying sensory innervation to the posterior third of the tongue, vallecula, anterior surface of the epiglottis (lingual branch), posterior and lateral walls of the pharynx (pharyngeal branch), and the tonsillar pillars (tonsillar branch). It also provides motor innervation to the stylopharyngeus muscle, involved in deglutition.
Patient Position: Supine
Lidocaine gel can be placed on tongue blade and patient “sucks” on this for several minutes. Lidocaine is available in a variety of concentrations and preparations. Topically, peak onset is usually within 15 minutes. Toxic plasma levels are possible to achieve, but not common with these techniques.
4cc of 4% Lidocaine or 0.5% Tetracaine can be placed in a nebulizer. The patient then inhales the nebulized local anesthetic for 5-7 min, or the tongue and posterior pharynx are sprayed with the atomizer.
Cetacaine spray (tetracaine and benzocaine combination) may also be used to provide anesthesia to the tongue and posterior pharynx. Keep in mind that the toxic dose of benzocaine is 100 mg (may cause methemoglobinemia, treated with the administration of methylene blue) and the toxic dose of Tetracaine is 100 mg in the adult (but toxicity has been reported at 40 mg). Check concentrations.
Viscous lidocaine 2-4 ml may also be used as a gargle (swish and swallow) for approx. 30 sec.
GLOSSOPHARYNGEAL NERVE BLOCK is performed when topical techniques are not completely effective in obliterating the gag reflex. This block can be performed after the mouth and oropharynx are adequately anesthetized. Branches of this nerve are most easily accessed as they transverse the palatoglossal folds (seen in figure 5, as soft tissue bilaterally). This is performed with the anesthetist standing contralateral to the side to be blocked and the patients mouth wide open. The palatopharyngeal fold (posterior tonsillar pillar) is identified and a tongue blade, held with the non-dominant hand, is introduced into the mouth to displace the tongue medially (contralateral side) creating a gutter between the tongue and the teeth. A 25g spinal needle is inserted into the membrane near the floor of the mouth at the base of the cul-de-sac (figure 4) and advanced slightly (0.25-0.5 cm). An aspiration test is performed. If air is aspirated, the needle has passed through the membrane (through and through). If blood is aspirated, the needle is redirected more medially. Then, 2 ml of 1% or 2% Lidocaine can be injected into the anterior tonsillar pillar 0.5 cm lateral to the base of the tongue (This most readily blocks the lingual branch). This block has been reported as painful, and may result in a persistent hematoma.
A posterior approach (*often used for tonsillectomy), may be difficult, in visualizing the site for needle insertion, which is behind the palatopharyngeal arch (where the nerve is in close proximity to the carotid artery). There is risk for arterial injection and bleeding, and the technique is usually reserved for otolaryngologists. Steps for this procedure can be found in other sources and are not cited here.
Complications: Systemic toxicity – can occur quickly when several different techniques are used. Topical anesthetics enter the circulation more quickly than when injected into tissues, and can be absorbed in the respiratory and GI tracts. Local anesthetics should be carefully measured with a syringe or cup (when able) to monitor the dosages the patient is receiving. Concentrations should be considered when using sprays or other such preparations. The lowest concentration possible should be used to minimize the risk of toxicity. Methemoglobinemia occurs when the ferrous molecule in hemoglobin is changed to its ferric state with essentially ionic bonds by oxidation. Injury or toxic agents convert abnormally large amounts of hemoglobin to methemoglobin, which does not function reversibly as an oxygen carrier. Results in cyanosis and many other symptoms which can progress to stupor, coma and death.
III. SUPERIOR LARYNGEAL NERVE (SLN) BLOCK
Indications: To block the internal (sensory) branch of the SLN, resulting in abolition of the gag reflex or hemodynamic responses to laryngoscopy or bronchoscopy.
Drugs: 2-4 ml of Lidocaine 1% or 2% lidocaine, with or without epinephrine.
Anatomy: At its origin from the vagus nerve (CN X), the SLN travels alongside with the vagus nerve deeply to the carotid artery, before becoming anterior. The internal branch of the superior laryngeal nerve originates from the SLN lateral to the cornu of the hyoid bone. It travels along inferior to the greater cornu, then pierces the thyrohyoid membrane, and travels under the mucosa in the pyriform recess. The internal branch of the SLN provides sensory innervation to the base of the tongue, superior epiglottis, aryeppiglottic folds, arytenoids and laryngeal mucosa (to just above and excluding the vocal cords). There are two branches: the ascending branch supplies the epiglottis and the vestibules of the larynx, whereas, the descending branch supplies innervation to the mucosa at the level of the vocal cords. *The external branch of the SLN supplies the motor innervation to the cricothyroid muscle.
(Left)Depicting the Vagus nerve branching into Superior Laryngeal and Recurrent Laryngeal nerve.
Note the insertion of Superior Laryngeal Nerve into ThyroHyoid Membrane.
Local Anesthetic: The internal branch is the nerve of interest in the superior laryngeal nerve block; it is blocked where it enters the thyrohyoid membrane just inferior to the caudal aspect of the hyoid bone. It provides anesthesia of the larynx from the epiglottis to the level of the vocal cords.
Patient Position: Supine, with head slightly extended.
Patient is asked to open the mouth widely, and the tongue is grasped using a guaze pad or tongue blade. A right angle forcep (e.g., Jackson-Krause) is covered with anesthetic-soaked guaze and is slid over the lateral tongue and down into the pyriform sinuses (recessus piriformis pear-shaped fossa in the wall of the laryngeal pharynx, lateral to the arytenoids cartilage, and medial to the lamina of the thyroid cartilage) bilaterally. Cotton swabs are held in place for 5 minutes. (Less common procedure).
Anesthetist is positioned on the ipsilateral side of the neck. The cornu of the hyoid bone is palpated transversally with the thumb and the index finger on the side of the neck immediately beneath the angle of the mandible and anterior to the carotid artery. To facilitate its identification, the hyoid bone is displaced toward the side being blocked. One hand displaces the carotid artery laterally and posteriorly. With the other hand, a 22 or 23 guage – 25 mm needle is “walked off” the cornu (cartilage) of the hyoid bone in an anterior caudad direction, aiming in the direction of the thyroid ligament, until it can be passed through the ligament. At a depth of 1-2 cm, 2 ml of 2% lidocaine with epinephrine is injected (after negative air and blood aspiration) into the space between the thyrohyoid membrane and the pharyngeal mucosa. An additional 1 ml is injected as needle is withdrawn. The block is repeated on the other side.
Technique Tips! Firmly displace the hyoid bone towards the side to be blocked, even if it causes the patient some minor discomfort. Use small amounts of sedation to offset patient discomfort.
Exercise caution – not to insert the needle into the thyroid cartilage, since injection of local anesthetic at the level of vocal cords may cause edema and airway obstruction.
If air is aspirated, laryngeal mucosa has been pierced, and the needle needs to be retrieved.
If blood is aspirated (superior laryngeal artery or vein), the needle needs to be redirected more anteriorly. Pressure should be applied to avoid hematoma formation.
Assessment of Block Efficacy: Patient has an acceptable block and tolerates awake intubation.
Complications: Systemic toxicity – can occur quickly when several different techniques are used. Topical anesthetics enter the circulation more quickly than when injected into tissues, and can be absorbed in the respiratory and GI tracts. Local anesthetics should be carefully measured with a syringe or cup (when able) to monitor the dosages the patient is receiving. Concentrations should be considered when using sprays or other such preparations. The lowest concentration possible should be used to minimize the risk of toxicity.
- Methemoglobinemia occurs when the ferrous molecule in hemoglobin is changed to its ferric state with essentially ionic bonds by oxidation. Injury or toxic agents convert abnormally large amounts of hemoglobin to methemoglobin, which does not function reversibly as an oxygen carrier. Can result in cyanosis, and many other signs and symptoms, progressing to stupor, coma and death.
Hematoma formation – from puncture during needle placement for injection or vascular structure damage. Maintain pressure long enough to prevent hematoma or continued bleeding.
Tracheal anatomy depicting Superior Laryngeal Nerve with ascending and descending branches.
Superior Laryngeal Nerve Block showing displacement technique.
Placement of Needle for the Superior Larnyngeal Nerve Block
IV. RECURRENT LARYNGEAL NERVE BLOCK (TRANSTRACHEAL or TRANSLARYNGEAL BLOCK)
Indications: Transtracheal injection performed to block the recurrent laryngeal nerve for awake laryngoscopy, fiberoptic and/or retrograde intubation. Abolition of the gag reflex or hemodynamic responses to laryngoscopy or bronchoscopy. Used to help avoid Valsalva-like straining that may follow other “awake” intubations (patient is sedated and spontaneously ventilating).
Drugs: Most often, 3-4 ml of Lidocaine 4 % is used. Also, 1% or 2% lidocaine, with or without epinephrine. * Keep total dose of local anesthetics in mind when several of these techniques are performed!
Anatomy: Translaryngeal block is most useful in providing topical anesthesia to the laryngotracheal mucosa, innervated by branches of the vagus nerve (CN X). The distal airway mucosa (like the upper airway from the SLN) receives innervation from the vagus nerve also, but via the recurrent laryngeal nerve (RLN). The right recurrent laryngeal nerve originates at the level of the right Subclavian artery, and loops around the inominate artery on the right, and around the aortic arch on the left. This nerve supplies sensory innervation to the vocal cords and trachea, and motor innervation to the vocal cords.
Translaryngeal injection of local anesthetic provides topical anesthesia for both vagal branches (SLN & RLN) since injection below the cords, through the cricothyroid membrane, and results in the solution being spread onto the tracheal (RLN) structures, and coughed onto the more (SLN) structures.
Patient Position: Supine, with neck hyperextended (or pillow removed and extended).
Technique: Inform the patient about the procedure, what is expected of him, and likelihood of coughing. Anesthetist should be in position to place index and third fingers of the non-dominant hand in the space between the thyroid and cricoid cartilages (identifying the cricothyroid membrane). The trachea can be held in place by placing the thumb and third finger on either side of the thyroid cartilage. The midline should then be identified and injected lightly to create a local skin wheal (using a 22-guage or smaller needle). A 10 ml syringe containing 4% lidocaine (or other desired concentration), is mounted on a 22-guage, 35 mm plastic catheter over a needle, and is introduced into the trachea. The catheter is advanced into the lumen, midline thru the cricothyroid membrane, at an angle of 45 degrees, in a caudal direction. *Immediately after the introduction of the catheter into the trachea, a loss of airway resistance and aspiration of air confirms placement, and the needle is removed from the catheter. The patient is then asked to take a deep breath and then asked to exhale forcefully. At the end of the expiratory effort, 3-4 ml of local anesthetic solution is rapidly injected into and over the back of the trachea. This will usually cause patient to first inhale to catch his or her breath and then forcefully cough, spreading the lidocaine over the trachea, making distal airway anesthesia more predictable This area is nearly devoid of major vascular structures.
Technique Tips! Caution! If a regular needle is used to inject (rather than a catheter), the lidocaine is injected rapidly and the needle is removed immediately!!! Surrounding structures, including the posterior tracheal wall can be damaged if the needle is not stabilized during injection of the local anesthetic and then be removed immediately!
The catheter should bet in place until the intubation is completed for the purpose of injecting more local anesthetic, if necessary, and to decrease the likelihood of subcutaneous emphysema.
Placement of fingers to identify the midline of the cricothyroid membrane.
Placement of the needle for the Transtracheal or Recurrent Laryngeal Nerve Block.
Transtracheal spread of local anesthetic with coughing.
Complications: Gastric Aspiration – This technique is possibly contraindicated in patients with high risk of gastric aspiration, but is believed by most authorities to actually decrease the risk, by decreasing risk of coughing and gag reflex during intubation.
Risk of Coughing this block usually rapidly results in a fit of coughing, which should be considered in patients whom coughing is undesirable or contraindicated. This block is contraindicated in patients diagnosed with an unstable neck, because it induces coughing. During performance of the block, the patient should not talk, swallow, or cough, if possible.
Vascular injury the needle does not need to be far off the midline of the cricothyroid membrane to encounter significant arterial and venous vessels. Pressure should be held over the injection site with an alcohol wipe after injection to prevent hematoma formation and subcutaneous emphysema
Structural injuries – surrounding structures, including the posterior tracheal wall and vocal cords can be damaged, especially if the needle is not stabilized during injection of the local anesthetic, or not removed immediately!
Intravascular injection – aspiration should be performed prior to the injection of local anesthetic.
Systemic toxicity - can occur quickly when several different techniques are used. As with all regional techniques, there is risk of systemic toxicity if maximum dosages of local anesthetics are exceeded. Topical anesthetics enter the circulation more quickly than when injected into tissues, and can be absorbed in the respiratory and GI tracts. Local anesthetics should be carefully measured with a syringe or cup (when able) to monitor the dosages the patient is receiving. Concentrations should be considered when using sprays or other such preparations. The lowest concentration possible should be used to minimize the risk of toxicity.
Methemoglobinemia occurs when the ferrous molecule in hemoglobin is changed to its ferric state with essentially ionic bonds by oxidation. Injury or toxic agents convert abnormally large amounts of hemoglobin to methemoglobin, which does not function reversibly as an oxygen carrier. It may result in cyanosis, and many other signs and symptoms, progressing to stupor, coma and death.
The risk if increased with airway blocks because more than one technique is frequently performed. *Thus, the combined dosages administered should be kept track of to avoid the risk of systemic toxicity.
Assessment of Block Efficacy: as with all of the airway blocks, the efficacy of is evaluated by blunting of airway reflexes such as coughing and gagging, and diminished pain and cardiovascular response to instrumentation of the airway.
Go to source: AIRWAY BLOCKSLidocaine Lollipop for Awake Fiberoptic Bronchoscopy
Anesthesiology 2006; Volume 104(6), June 2006, pp 1352-1353
Numerous techniques and maneuvers have been described to anesthetize the upper airway in preparation for awake tracheal intubation, notably the nerve block techniques to the superior laryngeal or the glossopharyngeal nerves as well as the topical application of a local anesthetic, in the form of a gel, spray, or inhaler. The current report describes the efficacy of a lollipop containing 150 mg lidocaine HCl for providing upper airway analgesia for patients undergoing awake fiberoptic bronchoscope (FOB) tracheal intubation or direct laryngoscopy.
After extensive search through Medline and multiple other databases about the stability of lidocaine HCl salt, a lidocaine lollipop (LL) was developed in collaboration with the pharmacy at the American University of Beirut. Fifty grams of white sugar was heated until liquefied; an equal amount of maple golden syrup was slowly added. For each lollipop, 3 ml of this mixture was poured into a small cylindrical container, to which 150 mg lidocaine HCl salt was added and stirred. As the temperature cooled down and before the mixture solidified, a small plastic stick was plunged at one end for holding the LL. The ready-to-use LL was then labeled and stored in a refrigerator.
The protocol used was approved by the internal review board, and informed consent was obtained from all participants. Exclusion criteria consisted of any history of allergic reaction to local anesthetics, diabetes, or risk for aspiration of gastric contents. All participants had noninvasive serial blood pressure measurements, pulse oximetry, and continuous electrocardiographic monitoring. A total of 45 patients aged 2578 yr, with American Society of Anesthesiologists physical status IIII, scheduled to undergo elective surgery and requiring general anesthesia and tracheal intubation were recruited. Premedication consisted of 5 mg oral diazepam and 0.2 mg intramuscular glycopyrrolate. All patients were given the LL on arrival to the holding area. The LL was easily consumed by all patients in 817 min. Its taste was described as good in more than 80% of patients and acceptable in the remaining participants. The onset of analgesia as depicted by sensation of tongue numbness was reported within 12 min.
Patients were randomized into the two groups with the help of a computer-generated table of random numbers. Group C received saline 30 ml and Group K received ketamine 40 mg in saline 30 ml. The preparations of 30 ml each were placed in an opaque container by a staff nurse who also asked patients to gargle with the preparation for 30 s after their arrival in the operation room. This nurse did not participate in the subsequent management of these patients. Anaesthesia was induced 5 min later. The patients could not be blinded because of the different tastes of the two preparations. (
lidocaine starts working in 1-2 min and reaches peak effect at 2-5 minutes, by mucosal
lasts 40 min with antisalagogue and 20 min without it
At least 50% of nebulized dose is lost to the environment
60 um or larger are the preferred drop size for airway
a pediatric esophagweal steph. placed 0.5 cm distal to et tube tip and inflated with 3-way stopcock and syringe facilitates nasotracheal intubation (Anesth Analg 2007;105)
obese patients with the glidescope (Anaesthesia Volume 67, Issue 3, pages 232–235, March 2012)Back to top
cost analysis of disposables like ambu scope show comparable cost to reusable (J Clin Anesth 2011;23:632)
Push tip on nasopharynx to clear tube fogging
most common cause of difficulty of passing the tibe is right arytenoid cartilage.
Place bevel facing the patients back for Oral, Place it up so it winds up down for nasal
UNDO-up for nasal, down for oral
focused by obtaining asharp image of a sheet of text held 1 cm in front of the fibreopticchannel port.
We have adapted a simple technique that easily and reliably secures the endotracheal tube at the proximal end of the insertion tube. The fibrescope controlbody has an instrument channel, the proximal end of which protrudes like a hook. From this instrument channel, the endotracheal tube may be easily secured by placing a rubber band at its proximal end around the 15 mm blue connector. Thereafter, the endotracheal tube is threaded over the shaft of the intubation fibrescope. Once positioned, the rubber band is rotated to achieve a figure-of-eight, and is then slid over the proximal end of the instrument channel (Figure). The rubber band firmly secures the endotracheal tube in place, and the tube can be released easily after the fibrescope has been correctly positioned. We have found this method of temporary securing of the endotracheal tube to be effective and reliable during fibreoptic intubation. (Neema et al. 54 (2): 159 — Canadian Journal of Anesthesia 2007)
Ask the awake patient to stick out their tongue and breathe deeply through the mouth. Your assistant should grasp the tongue with one hand and with the other gently extend the head. Traction on the tongue should be toward the ceiling (Figure). If the patient has jagged front teeth, avoid lacerating the tongue or frenulum linguae. n Instruct your assistant to monitor oxygen saturation while you are doing the intubation. 5Line up the fiberoptic shaft.Know where that tip points before it disappears from view!Stand on a lift so that the fiberoptic bronchoscope shaft will be straight when you hold it above the patient. Hold the bronchoscope handle in your right hand with the thumb lever down. With your left hand, hold the bronchoscope shaft between the 3rd and 4th white rings or at a point 15 to 20 cm from the shaft tip. If you are using the nasal route, insert the fiberoptic shaft before you advance the endotracheal tube. That way you will avoid having the tube provoke bleeding that will obscure your vision, and you will prevent the tube tip from tunneling under the mucosa. n Look at the shaft, not through the eye piece. Position the shaft above the middle of the patients mouth or nose at 90 degrees to the horizontal. n Flex the tip of the shaft maximally and position the shaft so that the flexed tip points precisely down the middle of the neck (Figure).
n Now straighten the tip. In an oral approach: without tilting or bending or rotating the shaft even a tiny bit, insert the shaft exactly in the midline of the mouth and oropharynx until the tip hits the rear of the mouth (about 9 cm). In a nasal approach, insert the tip into the nose, keeping the tip slightly flexed so that it follows the base of the nose until you view the posterior nasal pharynx. n Nowcarefully bring the eyepiece down to your eye or look at the TV monitor. Then slowly flex the tip of the shaft so you see the epiglottis or glottis, or, in a nasal approach, until you see the “tunnel” consisting of the palate above and the posterior nasal pharynx below.
If you get lost, withdraw the shaft completely and check the flexed tip orientation. If you get lost again, advance in the midline toward the darkest site, i.e. head for the black. n Advance the tip under the epiglottis until the cords come into view. If you find the tip off to one side of the glottis, rotate both shaft and handle until the tip is over the glottis. n If there is no open space between the epiglottis and posterior pharynx, have your assistant let go of the tongue and left up on the mandible. If you are midline, youll see the glottic opening.
Dissociative Awake Intubation with Ketamine (BMC Anesthesiology 2011;11:19) Not sure why, but they used sub-q which is inexplicableBack to top