Awake intubation of the adult trachea using the Bullard laryngo-scope

Awake intubation using the Bullard laryngoscope can be comfortably and easily performed in the adult. Five cases are presented in which tracheal intubation was performed under topical anaesthesia with light intravenous sedation. In each case, topical anaesthesia was performed by insertion of a Guedel oral airway, with lidocaine ointment applied to the inferior and posterior surfaces. In one case, Bullard intubation was successful where direct laryngoscopy and multiple attempts at bronchoscopic intubation by three different operators had failed. We conclude that the Bullard laryngoscope can be easily used in awake patients and may be a useful alternative where other methods for awake intubation have failed.     

Fibreoptic intubation

Although not widely utilized, fibreoptic techniques represent a dramatic advance in the management of the difficult intubation. Particularly suited to the awake patient in the elective setting, fibreoptic intubation can abo be useful in selected emergency situations, and can be done under general anaesthesia. In the awake patient fibreoptic intubation maintains a wide margin of safety while producing minimal patient discomfort, but requires adequate local anaesthesia of the airway. Intimate familiarity with the bronchoscope and the anatomy of the upper airway is essential as is careful attention to various aspects of technique. Intubation mannequins can be readily utilized to develop dexterity in bronchoscopic manipulation and intubation workshops are also effective in improving skills. This CME article provides the clinician with a detailed approach to the technique of fibreoptic intubation based on the author’s personal experience supplemented by a limited literature review. Fibreoptic intubation is not a difficult skill to master and should be in the armamentarium of all practising anaesthetists.     

Evaluation of the Augustine Guide™ for difficult tracheal intubation

Successful tracheal intubation with Augustine Guide ? (Augustine Medical, Inc., Eden Prairie, MN) in patients with normal airways has recently been described. There are no studies describing Augustine Guide (AG) use in patients with difficult airways. Accordingly, we studied AG intubation in a population of patients with expected difficult airways due to cervical spine pathology, limited mouth opening, obesity, facial trauma or deformity due to previous operation or radiation and in patients with unexpectedly difficult airways. A total of 44 patients were studied. The AG was used as a primary intubating tool in patients with known difficult airways (n = 36) and as a secondary intubating tool in patients with unexpected inability to intubate using conventional direct laryngoscopy (n = 8). Airway difficulty was predicted by history and physical examination. Intubations were performed under general anaesthesia in 40 of the 44 patients studied. In four patients with predictably difficult airways, topical anaesthesia and sedation were used. Backup methods to achieve intubation were available. Thirty-two of the 36 with known or suspected difficult airways were classified as Mallampati Class III or IV. In the remaining eight patients the preoperative examination suggested an easy airway; however, after induction of general anaesthesia, their laryngeal inlet could not be seen using direct laryngoscopy. Using the AG, all were intubated successfully (36/44 at the first attempt, in 8/44 repositioning of the AG to allow successful laryngeal entry of the stylet was necessary). There were no failures or complications secondary to AG use. This study shows that the AG is a useful device for oral tracheal intubation in patients with known or unexpectedly difficult airways.     

Randomized comparison of outcome after propofol-nitrous oxide or enflurane-nitrous oxide anaesthesia in operations of long duration

A randomized, prospective, comparative study was performed to evaluate induction characteristics, haemodynamic changes and recovery in 60 ASA I-II patients undergoing mainly gynaecological laparotomies with either propofol or thiopentone-enflurane anaesthesia. The propofol group (n = 30) received 2 mg.kg-1 propofol for induction of anaesthesia followed by propofol infusion. The thiopentone-enflurane group (n = 30) received thiopentone 4 mg.kg-1 for induction followed by enflurane (0.5-2 per cent). All patients received nitrous oxide (66 per cent] in oxygen begun one minute after tracheal intubation, and fentanyl (1.5 micrograms.kg-1) four minutes prior to induction. Other drugs administered during or after anaesthesia were similar among the groups. Haemodynamic measurements were similar between propofol and enflurane groups except after tracheal intubation when the mean arterial pressure was lower in the propofol group (P less than 0.05). The propofol group had significantly less (P less than 0.01) emesis in the recovery room than the enflurane group. The propofol group experienced significantly less (P less than 0.05) dizziness, depression/sadness and hunger than the enflurane group in the postoperative period as assessed with a visual analogue questionnaire. We conclude that propofol provided better outcome than enflurane in terms of these nonvital but annoying outcome measures after relatively long intra-abdominal operations.     

Anterior mediastinal mass in a patient susceptible to malignant hyperthermia

We report a malignant hyperthermia- susceptible patient who required investigation for a large, symptomatic anterior mediastinal mass. Multiple attempts at tissue diagnosis under local anaesthesia were unsuccessful. Following awake fibreoptic tracheal intubation, general anaesthesia was administered using ketamine, midazolam, and nitrous oxide, maintaining spontaneous ventilation. Prophylactic dantrolene was not used, to avoid potential muscle weakness and respiratory compromise. Diagnostic mediastinotomy was performed without incident. We conclude that ketamine anaesthesia is appropriate for patients with anterior mediastinal masses, and is considered safe in malignant hyperthermiasusceptible patients. Nous rapportons l’observation d’un patient connu pour sa susceptibilité à l’hyperthermie maligne et qui doit subir une investigation pour une masse médiastinale antérieure symptomatique. De nombreuses tentatives de biopsies diagnostiques ont déjà faites sans succès sous anesthésie locale. A la suite d’une intubation trachéale vigile au fibroscope, une anesthésie générale à la kétamine, au midazolam et au protoxyde d’azote est administrée en ventilation spontanée. On ne donne pas de dantrolène prophylactiquement afin d’éviter une détérioration de la fonction respiratoire par faiblesse musculaire. Une médiastinostomie diagnostique est réalisée sans incident. Nous concluons que l’anesthésie à la kétamine est appropriée pour les porteurs de masses médiatinales antérieures et que cet agent anesthésique ne présente pas de dangers particuliers pour les patients dont la susceptibilité à l’hyperthermie maligne est connue.     

The laryngeal mask airway: clinical appraisal in 250 patients

The laryngeal mask airway consists of a tubular oropharyngeal airway to the distal end of which is sealed a silicone laryngeal mask with an inflatable rim which provides an airtight seal around the larynx. It provided a clear airway in 238 of 250 elective and emergency non-obstetrical patients for a wide variety of surgical procedures, ranging from minor gynaecological and urological procedures to major abdominal and orthopaedic surgery with either spontaneous respiration or intermittent positive pressure ventilation. Anaesthetic techniques and drugs were similar to those which would have been used for the same procedures if face-mask or tracheal intubation had been employed. Blind insertion of the laryngeal mask airway was successful at the first attempt in 187 patients, some manipulation was required in 61 patients, and insertion was impossible in two patients, each of whom had a small mouth. In ten patients tracheal intubation was required because of airway obstruction or a large gas leak. The LM airway does not require laryngoscopy for its insertion, it relieves the anaesthetist's hands from holding a face-mask, it cannot be misplaced in the oesophagus, and it is well tolerated during emergence from anaesthesia.     

Laryngeal mask airway with mouth opening less than 20 mm

We describe the use of a laryngeal mask airway in three adult patients whose mouth opening varied from 12 mm to 18 mm. The first patient’s incisai opening was 12 mm. His airway was otherwise normal and the standard laryngeal mask was used as the definitive airway for the 90 min revision of facial scars and bone graft to mandible. The second patient, who had an incisai opening of 18 mm, was scheduled for posterior fossa craniotomy. She adamantly refused awake fibreoptic tracheal intubation. Following induction of general anaesthesia, a standard laryngeal mask was inserted and, through this, fibreoptic intubation was performed. The third patient, in addition to a mouth opening of only 18 mm, had limited neck movement from previous flap reconstruction following mandibulectomy, hemiglossectomy and radical neck dissection. For three more reconstructive head and neck procedures that ranged from 90 min to nine hours, the flexible reinforced laryngeal mask was inserted under topical anaesthesia and its correct position confirmed by fibreoptic laryngoscopy before induction of general anaesthesia. Maintenance of anaesthesia in all cases was uneventful and there were no postoperative complications. Cette observation décrit l’utilisation du masque laryngé chez trois adultes avec une ouverture buccale dont les limites se situaient entre 12 et 18 mm. Le premier patient avait une ouverture interincisive de 12 mm. Ses voies respiratoires étaient par ailleurs normales et un masque laryngé standard a été utilisé pour le maintien de la perméabilité des voies aériennes pendantune intervention de 90 min effectuée pour retoucher des cicatrices faciales et effectuer une greffe osseuse à la machoire. La seconde patiente dont l’ouverture interincisive était limitée à 18 mm était programmée pour une craniotomie de la fosse postérieure. Elle refusait intensément l’intubation vigile par fibroscope. Après l’induction de l’anesthésie générale, l’intubation fibroscopique a été réalisée a travers un masque laryngé standard déjà inséré. Le troisième patient avait, en plus d’une restriction de l’ouverture interincisive à 18 mm, une limitation des mouvements cervicaux causés par une intervention de reconstruction avec lambeau cutané après une mandibulectomie, une hémi glossectomie et une dissection radicale du cou. Pour trois autres chirurgies de reconstruction cervicale et céphalique ultérieures, un masque laryngé renforcé a été inséré sous anesthésie topique et sa position vérifiée sous laryngoscopie fibroscopique avant l’induction de l’anesthésie. Dans tous les cas, l’anesthésie s’est déroulée sans incidents et sans complications postopératoires.

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An erratum to this article is available at .     

Onset of vecuronium neuromuscular block is more rapid in patients undergoing Caesarean section

This investigation was carried out in ten patients undergoing elective Caesarean section and the results were compared with those of a control group of ten nonpregnant females of the same age group. The study investigated the onset of vecuronium neuromuscular block and the conditions of tracheal intubation when ketamine (1.5 mg.kg-1)-vecuronium 100 micrograms.kg-1) sequence was used for rapid-sequence induction of anaesthesia. The ulnar nerve was stimulated supra-maximally at the wrist with train-of-four stimuli every 20 sec, and the electromyographic response of the adductor pollicis muscle was displayed. The onset of 50% neuromuscular block as monitored by electromyography was shorter in the Caesarean group (80 +/- 30 sec) than in the control group (144 +/- 43 sec). The conditions of intubation at 50% block were adequate in both groups. Also, the onset of 90% block was shorter in the Caesarean group. The time of recovery to T1/control ratio of 25% was longer in the Caesarean group (46 +/- 10 min) than in the control patients (28 +/- 10 min). The results show that administration of vecuronium according to body weight results in a more rapid onset and delayed recovery of neuromuscular block in pregnant women undergoing Caesarean section than in the nonpregnant control patients.     

The laryngeal mask airway: its features,effects and role

The laryngeal mask airway was designed as a new concept in airway management and has been gaining a firm position in anaesthetic practice. Numerous articles and letters about the device have been published in the last decade, but few large controlled trials have been performed. Despite widespread use, the definitive role of the laryngeal mask has yet to be established. In some situations, such as after failed tracheal intubation or in anaesthesia for patients undergoing laparoscopic or oral surgery, its use is controversial. There are a number of unresolved issues, for example the effect of the laryngeal mask on regurgitation and whether or not cricoid pressure prevents placement of the mask. We review the techniques of insertion, details of misplacement, and complications associated with the use of the laryngeal mask. We discuss the features and physiological effects of the device, including the changes in intra-cuff pressure during anaesthesia and effects on blood pressure, heart rate and intra-ocular pressure. We then attempt to clarify the role of the laryngeal mask in airway management during anaesthesia, based on the current knowledge, by discussing the advantages and disadvantages as well as the indications and contraindications of its use. Lastly we describe the use of the laryngeal mask in circumstances other than airway maintenance during anaesthesia: fibreoptic bronchoscopy, tracheal intubation through the mask and its use in cardiopulmonary resuscitation.     

Nicardipine and verapamil attenuate the pressor response to laryngoscopy and intubation

In a prospective, double-blind study, we compared the efficacy of iv nicardipine hydrochloride and verapamil hydrochloride in attenuating the cardiovascular responses to laryngoscopy and tracheal intubation, in 45 patients undergoing elective surgery with general anaesthesia. Patients were allocated randomly to one of three groups of 15 patients. Patients in Group I received saline while those in Groups II and III received nicardipine hydrochloride, 0.03 mg · kg^{? 1} or verapamil hydrochloride, 0.1 mg · kg^{? 1} iv three minutes before laryngoscopy and intubation. Patients in Group I showed the greatest increase in SBP 25.4 ± 2.2 mmHg and HR 35.7 ± 3.8 beats · min^{? 1} at one minute after intubation (P < 0.001), and these changes persisted throughout the study period albeit with decreasing magnitude. After drug administration, patients in Groups II and III demonstrated increases in HR of 26 ± 2.4 and 15.1 ± 2.2 beats · min^{? 1} and decreases in SBP of 24.8 ± 2.0 and 18.8 ± 2.4 mmHg respectively (P < 0.001). It is concluded that nicardipine and verapamil are effective in attenuating pressor responses to laryngoscopy and intubation but did not control the tachycardia.     

Transforaminal escape of a lumbar epidural catheter

A patient is presented whose lumbar epidural catheter was found to lie in the paravertebral tissues during a right radical nephrectomy. The catheter had been placed with the patient awake and the procedure performed in a routine fashion without difficulty or indication of catheter malposition. Four ml of 2% CO2 lidocaine were initially injected as a test dose without any demonstrable effect. After the induction of general anaesthesia, fentanyl 100 mu and 0.25% bupivacaine 10 ml were injected slowly into the catheter. Previous studies suggest that transforaminal escape of an epidural catheter occurs after 1-6% of insertions. It may occur without nerve root symptoms during catheter placement. The authors recommend that epidural catheters be introduced whilst the patients are awake and an effective block demonstrated before induction of general anaesthesia.     

Butorphanol compared with fentanyl in general anaesthesia for ambulatory laparoscopy

Butorphanol was compared with fentanyl as the narcotic component of general anaesthesia for ambulatory laparoscopic surgery. This double-blind, randomized study enrolled 60 healthy women who received equianalgesic doses of fentanyl 1 microgram.kg-1 (F, n = 30) or butorphanol 20 micrograms.kg-1 (B, n = 30) prior to induction of anaesthesia. Tracheal anaesthesia was maintained with nitrous oxide/oxygen, isoflurane, and succinylcholine by infusion. Intraoperatively, patients who received B demonstrated lower pulse rate before and after intubation (P less than 0.05, P less than 0.01) and lower diastolic blood pressure after intubation (P less than 0.01). Anesthesiologists judged the maintenance phase as satisfactory more often with B (P less than 0.05). Postoperatively, there were no differences in analgesic need. No major side-effects occurred in either group. Among minor side-effects, patients who received B reported postoperative sedation more often, 77% vs 37% (P less than 0.01), which occurred during the first 45 min of recovery (P less than 0.05). Discharge times were not different. On the first postoperative day, more subjects who received B were satisfied with their anaesthesia experience (P less than 0.05). Butorphanol 20 micrograms.kg-1 is an acceptable alternative analgesic in general anaesthesia for ambulatory laparoscopy.     

A comparison of fentanyl,esmolol, and their combination for blunting the haemodynamic responses during rapid-sequence induction

The purpose of this randomized, double-blind study was to compare the ability of a combination of fentanyl and esmolol to blunt the haemodynamic effects of intubation with that of either agent alone. Patients received fentanyl or saline four minutes before, and esmolol or saline two minutes before rapid-sequence induction of anaesthesia. The F2 group (n = 24) received fentanyl 2 micrograms.kg-1, the E2 group (n = 24) received esmolol 2 mg.kg-1, the F2/E2 group (n = 25) received a combination of fentanyl 2 micrograms.kg-1 and esmolol 2 mg.kg-1, and the F5 group (n = 26) received fentanyl 5 micrograms.kg-1. Following tracheal intubation, the maximum percent change from baseline heart rate was less in the F2/E2 and F5 groups (12% and 16% respectively) than in the E2 group (34%)(P < 0.05). The maximum percent changes from baseline systolic blood pressure in the F2/E2 and F5 groups (15% and 6% respectively) were less than in the F2 and E2 groups (24% and 33% respectively) (P < 0.05). The combination of a low dose of fentanyl and esmolol provides an alternative to a higher dose of fentanyl for blunting the haemodynamic responses to laryngoscopy and tracheal intubation during rapid-sequence induction in healthy patients.     

Bolus doses of esmolol for the prevention of perioperative hyper-tension and tachycardia

The effectiveness of esmolol, an ultra short-acting cardioselective beta blocker, in the prevention and treatment of post-intubation haemodynamic perturbations, was investigated. Forty-eight ASA physical status I and II patients undergoing hysterectomy were randomly assigned to receive a single intravenous bolus of placebo, esmolol 100 mg, or esmolol 200 mg in a double-blind fashion. This was administered over 15 sec, and immediately followed by thiopentone 3-5 mg.kg-1, succinylcholine 1.5 mg.kg-1, and tracheal intubation 90 sec later. The heart rate following induction of anaesthesia was lower in the esmolol 200 mg group (P less than 0.01); following intubation, the increase in heart rate in the placebo group was greater than in the esmolol groups (P less than 0.05). The systolic blood pressure post-induction was lower in the esmolol 200 mg group (P less than 0.05); following intubation, however, no significant differences were seen among groups in systolic, diastolic, or mean blood pressures. Following tracheal intubation, the incidence of ventricular arrhythmias was lower in the esmolol groups (P less than 0.05). In summary, esmolol in 100 mg and 200 mg doses was effective in mitigating the haemodynamic response following tracheal intubation.     

A comparison of the myocardial metabolic and haemodynamic changes produced by propofol-sufentanil and enflurane-sufentanil anaesthesia for patients having coronary artery bypass graft surgery

The purpose of this study was to compare propofol-sufentanil with enflurane-sufentanil anaesthesia for patients undergoing elective coronary artery bypass graft (CABG) surgery with respect to changes in (1) haemodynamic variables; (2) myocardial blood flow and metabolism; (3) serum cortisol, triglyceride, lipoprotein concentrations and liver function; and (4) recovery characteristics. Forty-seven patients with preserved ventricular function (ejection fraction greater than 40%, left ventricular end diastolic pressure less than or equal to 16 mmHg) were studied. Patients in Group A (n = 24) received sufentanil 0.2 microgram.kg-1 and propofol 1-2 mg.kg-1 for induction of anaesthesia which was maintained with a variable rate propofol (50-200 micrograms.kg-1.min-1) infusion and supplemental sufentanil (maximum total 5 micrograms.kg-1). Patients in Group B (n = 23) received sufentanil 5 micrograms.kg-1 for induction of anaesthesia which was maintained with enflurane and supplemental sufentanil (maximum total 7 micrograms.kg-1). Haemodynamic and myocardial metabolic profiles were determined at the awake-sedated, post-induction, post-intubation, first skin incision, post-sternotomy, and pre-cardiopulmonary bypass intervals. Induction of anaesthesia produced a larger reduction in systolic blood pressure in Group A (156 +/- 22 to 104 +/- 20 mmHg vs 152 +/- 26 to 124 +/- 24 mmHg; P less than 0.05). No statistical differences were detected at any other time or in any other variable including myocardial lactate production (n = 13 events in each group), time to tracheal extubation and time to discharge from the ICU. We concluded that, apart from hypotension on induction of anaesthesia, propofol-sufentanil anaesthesia produced anaesthetic conditions equivalent to enflurane-sufentanil anaesthesia for CABG surgery.     

Anaesthetic management of acute blunt thoracic trauma

Sunnybrook Health Science Centre is an adult regional trauma unit serving metropolitan Toronto and environs. We undertook a nvo-year retrospective review of patients admitted to our institution with blunt thoracic trauma. Three hundred and thirty-three patients with blunt trauma and an injury severity score (ISS) greater than 17 required emergency surgery. Of these, 208 had blunt thoracic injuries while 125 did not have chest injuries. Both groups were similar with respect to age but patients with thoracic trauma had a greater ISS. (P < 0.05) and greater intraoperative mortality (P < 0.01). The aetiology of the intraoperative deaths with one exception was exsanguination. Emergency thoracotomy or sternotomy indicated a poor prognosis with a mortality rate of 80%. The most common intraoperative problem was an elevated airway pressure. Awake intubation was undertaken in 77.5% of patients requiring anaesthesia and surgery because of the potentially compromised airways and difficult intubations due to the nature of the associated injuries. Finally, 74% of patients undergoing urgent surgery required mechanical postoperative ventilation. The presence of blunt chest trauma should be considered a marker of the severity of injury sustained by the patient.     

Attenuation of the catecholamine response to tracheal intubation with oral clonidine in children

We conducted a prospective, randomized, double-blind, controlled clinical trial to examine (1) whether plasma catecholamine (CA) concentrations increased in response to tracheal intubation in children, and (2) the effects of clonidine on the CA responses. Sixty children (ASA physical status I) aged 7– 13 yr were allocated to one of three groups (n = 20 for each group): diazepam 0.4 mg · kg^{? 1} (active control), clonidine 2 μg · kg^{? 1}, or clonidine 4 μg · kg^{? 1} po. These agents were administered 105 min before induction of anaesthesia followed by oral atropine 0.03 mg · kg^{? 1} given 60 min before anaesthesia which was induced with thiamylal 5 mg · kg^{? 1} and tracheal intubation was facilitated with vecuronium 0.2 mg · kg^{? 1}. Laryngoscopy, lasting 30 sec, was attempted two minutes after administration of the induction agents. Serial values for blood pressure, heart rate, and venous plasma CA concentrations were compared among the three groups and with the respective preinduction measurements. Children receiving diazepam or clonidine 2 μg · kg^{? 1} showed remarkable increases in systolic and diastolic blood pressures, heart rate, and plasma CA concentrations in response to tracheal intubation (P < 0.05). The increases were similar for the two regimens. These haemodynamic and CA changes were smaller in children receiving clonidine 4 μg · kg^{? 1} (P < 0.05). The haemodynamic responses were positively correlated with the CA responses. These findings indicate that tracheal intubation following rapid sequence induction of anaesthesia in children provokes a reflex increase in sympathetic activity characterized by increased plasma CA concentrations, and that attenuation of the cardiovascular changes with a high oral dose of clonidine may be due to suppression of the increase in sympathetic activity evoked by the intubation.     

Ankylosing spondylitis: lateral approach to spinal anaesthesia for lower limb surgery

We describe three patients with long-standing ankyolsing spondylitis (AS) who underwent lower limb joint surgery under spinal anaesthesia. At preoperative assessment, it was considered that intubation of the trachea was likely to be difficult or impossible and previous general anaesthesia was associated with increased morbidity. Midline approach spinal anaesthesia failed but the lateral approach was successful. Spinal anaesthesia was induced using a 24 gauge Sprotte (Pajunk) needle with 3.5 ml heavy bupivacaine 0.5% at the L_3–4 interspace with the patients in the sitting position. This resulted in adequate sensory blockade for the surgical procedure. None of the patients required airway interventions but equipment and aids to secure airway were available.     

Lansoprazole reduces preoperative gastric fluid acidity and volume in children

The purpose of this study was to explore the efficacy of lansoprazole, a proton pump inhibitor, in reducing the acidity and volume of gastric aspirate in children immediately following the induction of anaesthesia. One hundred healthy in-patients aged 3–11 yr undergoing elective surgery were randomly allocated to four groups (n = 25 each): lansoprazole-lansoprazole, placebo-placebo, placebo-lansoprazole, and lansoprazole-placebo. For each treatment regimen, the first medication was administered at 9:00 pm on the night before surgery and the second at 5:30 am on the morning of the day of surgery (three hours preoperatively). The dose of lansoprazole was 30 mg (approximately 1.4 mg · kg^?1 mean). Children were offered 10 ml · kg^?1 apple juice three hours before induction of anaesthesia. After induction of anaesthesia and tracheal intubation, gastric fluid was aspirated through a large-bore, multiorifice orogastric tube and analyzed for pH and total fluid volume. Lansoprazole increased gastric fluid pH and decreased gastric fluid volume regardless of whether it was administered before or after placebo. Two consecutive doses of lansoprazole was the most effective means of increasing the pH and reducing the volume of gastric aspirate; in this group, there were no subjects with gastric aspirate volume >0.4 ml · kg^?1 and pH <2.5. Oral lansoprazole, at least 30 mg, given on the night before surgery or on the morning of surgery will improve the gastric environment at the time of induction of paediatric anaesthesia. The most effective regimen was two doses (at bedtime and on the morning) of lansoprazole.