Fibreoptic intubation has been established as a major advance in the management of difficult or failed intubation in the awake patient. If necessary, it may be performed under general anaesthesia with either spontaneous or controlled ventilation. This should be considered early in the management of failed intubation, before multiple attempts with other techniques lead to haemorrhage and oedema in the airway. We describe here selected case reports to illustrate this in 8 different situations. This is followed by a brief review of the technique and indications of fibreoptic intubation.
A 62-year-old male underwent off-pump coronary artery grafting surgery while cerebral function was monitored with bispectral index (BIS). The BIS monitoring was continued into the immediate postoperative period, during which time the patient experienced a cardiopulmonary arrest. The changes in the BIS values helped the resuscitating team in assessing the cerebral response to the cardiopulmonary resuscitation.
The aim of this randomised, controlled trial was to determine the optimum dose of fentanyl in combination with propofol 2.5 mg x kg(-1) when inserting the Classic Laryngeal Mask Airway. Seventy-five ASA I or II patients were randomly assigned to five groups of fentanyl dosage: 0 microg x kg(-1) (placebo), 0.5 microg x kg(-1), 1.0 microg x kg(-1), 1.5 microg x kg(-1) and 2.0 microg x kg(-1). Anaesthesia was induced by first injecting the study drug over 10 seconds. Three minutes after the study drug was injected, propofol (2.5 mg x kg(-1)) was injected over 10 seconds. The Classic Laryngeal Mask Airway was inserted four minutes and 30 seconds after injection of the study drug. Insertion conditions were evaluated using a four-category score. Thirty-nine males and 36 females aged 19 to 59 years were studied. The incidence of prolonged apnoea increased as fentanyl dose increased. We found that there was a high rate of successful first attempt at insertion with 1 microg x kg(-1) and 1.5 microg x kg(-1), 93% and 87% respectively, compared to 87% in the 2.0 microg x kg(-1) group. The 1.0 microg x kg(-1) group also achieved an 80% optimal insertion conditions score of 4, compared to 73% in the 1.5 microg x kg(-1) group and 80% in the 2 microg x kg(-1) group. Therefore we recommend 1.0 microg x kg(-1) as the optimal dose of fentanyl when used in addition to propofol 2.5 mg/kg for the insertion of the Classic Laryngeal Mask Airway.
We compared the performance of the Ambu AuraOnce Laryngeal Mask with that of the LMA Classic laryngeal mask airway during controlled anaesthesia. Forty patients requiring intermittent positive pressure ventilation were studied using a randomised crossover design. The mean (SD) oropharyngeal leak pressure for the Ambu device (19 (7.5) cmH2O) was significantly greater than for the LMA Classic (15 (5.2) cmH2O; p = 0.004), and the number of attempts for successful insertions was significantly less (39 (50%) vs 45 (56%), respectively; p = 0.02). There was one failure to obtain a patent airway with the Ambu Laryngeal Mask and none with the LMA Classic. Insertion of the Ambu Laryngeal Mask required more manipulations to achieve a patent airway than did the LMA Classic (6 (15%) vs 1 (2.5%), respectively; p = 0.045), but the time taken for insertion was similar between the two groups. The incidence of trauma, grade of fibreoptic view, peak airway pressure and quality of ventilation during maintenance of anaesthesia were similar in both groups.
Two children with Tetralogy of Fallot presented for dental extraction. Anaesthesia was induced rapidly and smoothly by inhalation of sevoflurane. We discussed the advantages of sevoflurane as an induction agent as compared to halothane in these children.
Intubating conditions under halothane anaesthesia aided with alfentanil 20 micrograms.kg-1 were compared with suxamethonium 2 mg.kg-1 in 40 children presenting for day dental procedures. The condition of vocal cords, jaw relaxation and presence of movement and coughing were scored to give the overall intubating conditions. Successful intubation was achieved in 100% of the suxamethonium group and 94.7% of the alfentanil group. The cardiovascular response to intubation was attenuated in the alfentanil group. Some 43.7% of those receiving suxamethonium developed myalgia the day after surgery compared with 0% in the alfentanil group (P < 0.01).
A case of severe bronchospasm occurring during epidural anaesthesia in a patient undergoing Caesarean section is described. The aetiology of the bronchospasm may have been related to sympathetic nervous blockade allowing unopposed parasympathetically mediated bronchoconstriction.
This is a preliminary report on the use of the modified Airway Management Device in 50 spontaneously breathing patients undergoing elective day care surgery. We were successful in establishing a clear airway in all 50 patients, 46 of these patients had a patient airway on the first attempt. All patients were successfully managed with the Airway Management Device throughout the surgery. Partial airway obstruction during maintenance of anaesthesia occurred in three cases requiring only minor manipulations. Our result showed that the Airway Management Device may be used as an alternative airway management in anaesthesia.
AIM: This was a randomized single blinded study to determine optimal size for Ambu®LMA (ALMA) among Malaysian adult population.
METHODS: One hundred and twenty six non-paralyzed anaesthetized adult patients were block randomized into size 3, 4 and 5 Ambu®LMA. Optimal size is defined primarily by oropharyngeal pressure (OLP). Pharyngeal injury and ease of insertion are also taken into consideration.
RESULTS: Mean OLP was significantly higher for Size 4 and 5 compared to size 3 (p<0.001) but similar between size 4 and 5. Number of insertion attempts and insertion time were similar between sizes. Size 5 required more manipulations during insertion (p<0.005) and had higher pharyngeal injury (p=0.001) compared to size 3 and 4.
DISCUSSION: We recommend size 4 ALMA as the optimal size for Malaysian adults in view of the higher OLP compared to size 3, yet less pharyngeal injury than size 5 in spontaneously breathing patients.
The 50% and 95% effective doses of desflurane for removal of the classic laryngeal mask airway after suction of the upper airway, in anaesthetised spontaneously breathing adult patients, are not known. To determine these, we studied 38 healthy patients, aged between 18 and 44 years. The target desflurane concentration in each individual patient was determined by the Dixon up-and-down method. When the predetermined target end-tidal desflurane concentration reached steady state, we kept a constant end-expiratory partial pressure between the alveolus and the brain for 10 min before attempting to remove the classic laryngeal mask airway after suctioning the upper airway. The initial desflurane target concentration was set at 6% and up-down desflurane increments were 0.1%. This continued until there were at least six crossover pairs. From the probit analysis, the 50% effective dose of desflurane was 5.29% (95% CI 5.132-5.379%) and the 95% effective dose was 5.55% (95% CI 5.429-6.394%).
We have compared the effect of rocuronium and succinylcholine on intraocular pressure (IOP) during rapid sequence induction of anaesthesia using propofol and fentanyl, in a randomized double-blind study. We studied 30 adult patients, allocated to one of two groups. Anaesthesia was induced with fentanyl 2 micrograms kg-1 and propofol until loss of verbal response. This was followed by succinylcholine 1.5 mg kg-1 (group S; n = 15) or rocuronium 0.9 mg kg-1 (group R; n = 15). Laryngoscopy was performed 60 s later. IOP, mean arterial pressure (MAP) and heart rate (HR) were measured before induction, immediately before intubation and every minute after intubation for 5 min. A Keeler Pulsair air impulse tonometer was used to measure IOP and the mean of two readings obtained in the right eye at each measurement time was recorded. Intubating conditions were evaluated according to a simple scoring system. IOP in the succinylcholine group was significantly greater than that in the rocuronium group (mean 21.6 (SEM 1.4) mm Hg vs 13.3 (1.4) mm Hg; P < 0.001). Intubating conditions were equally good in both groups. We conclude that with rapid sequence induction of anaesthesia using propofol and fentanyl, rocuronium did not cause as great an increase in IOP as succinylcholine and may be an alternative in open eye injury cases.
We conducted a double-blind, randomised, placebo-controlled study evaluating the efficacy of prophylactic metaraminol for preventing propofol-induced hypotension. Thirty patients aged 55-75 years undergoing general anaesthesia were randomly allocated to receive either metaraminol 0.5 mg or saline before administration of fentanyl 1 microg.kg(-1) and propofol 2 mg.kg(-1). Induction of anaesthesia was associated with a decrease in mean and systolic arterial pressure in both groups (p = 0.0001). However, there was no significant difference between the two groups. These results show that prophylactic use of metaraminol 0.5 mg does not prevent the decrease in blood pressure following fentanyl and propofol induction in older patients.
We present the case of a 24-year-old woman with acute septicemic melioidosis resulting from inhaled infective dust during a blast injury. With appropriate antibiotic treatment and supportive therapy in the ICU, the patient made an uneventful recovery.
Thirty-one healthy women who underwent Caesarean section were studied in a double-blind trial to compare the effectiveness of epidural 0.5% bupivacaine plain, 0.5% bupivacaine plus 100 micrograms fentanyl and 0.5% bupivacaine plus 50 micrograms fentanyl in the prevention of intraoperative pain. There was no difference in the quality of analgesia between the three groups. The incidence of complications was significantly higher in the 0.5% bupivacaine plus 100 micrograms fentanyl group compared with the other two groups.
A 27-yr-old lady with a past history of prolonged ventilation presented with worsening respiratory distress caused by tracheal stenosis. She required urgent tracheal resection and reconstruction. Because of the risk of an acute respiratory obstruction, spinal anaesthesia was used to establish cardiopulmonary bypass by cannulating the femoral artery and femoral vein. Adequate gas exchange was possible with full flow rate. Thoracotomy was then carried out to mobilize the left main bronchus. After successfully securing an airway by intubation of the left main bronchus, cardiopulmonary bypass was discontinued and tracheal resection and anastomosis was done under conventional one lung anaesthesia.
We compared the performance of the LMA Supreme (SLMA) with the I-Gel during anaesthesia in spontaneously breathing adult patients. Ninety patients with American Society of Anesthesiologists physical status I or II were studied in a prospective randomised controlled study. Our primary outcome measure was oropharyngeal leak pressure. We also compared the overall insertion success rate, ease of insertion, adequacy of ventilation and incidence of complications. The mean (SD), oropharyngeal leak pressure for the SLMA was 25.6 (5.1) cmH2O, which was greater than for the I-Gel 20.7 (5.9) cmH2O (P = 0.0001). The first attempt and overall insertion success rates were similar between the two groups (SLMA 97.8 and 97.8%; I-Gel 93.3 and 100%, P = 0.132). The SLMA was rated easier to insert than the I-Gel (P = 0.011), but the time taken for insertion (P = 0.433) was similar. The incidence of complications was low in both groups. The grade of fibreoptic view was better with the I-Gel than the SLMA (P = 0.001). We conclude that in adults with normal airways, the SLMA is easier to insert and provides a higher oropharyngeal leak pressure, but fibreoptic views are better with the i-gel.
We report our use of a superficial cervical plexus block to manage three adults who presented for drainage of dental abscesses. All patients had difficult airways related to severe trismus (preoperative inter-incisor distance < or = 1.5 cm). The first two patients, whose abcesses involved both the submandibular and submasseteric spaces, were managed with combined superficial cervical plexus and auriculotemporal nerve block. In a third patient, a superficial cervical plexus block alone was sufficient because the abscess was confined to the submandibular region. The blocks were successful in all three cases with minimal requirement for supplemental analgesia. We recommend the consideration of superficial cervical plexus block, and if necessary an auriculotemporal nerve block, for the management of selected patients with difficult airways who present for drainage of dental abcesses.
Pulmonary hypertension in pregnancy is a rare condition but is associated with a high mortality. We report the case of a 29 year old female in early pregnancy with Protein C and S deficiency with recurrent deep venous thrombosis and pulmonary embolism and subsequent secondary pulmonary hypertension. The patient was counselled and consented for termination of pregnancy with tubal sterilization. She was administered continuous spinal anaesthesia with invasive monitoring. The successful anaesthetic management of this condition is described.