Search PubMed⌕ Search

Biomedical subjects

J Brimacombe

Publications and source records attributed to J Brimacombe.

At least 19 recordsLinked to original sources
PubMed2001

A modified laryngeal mask in the endoscopic management of an esophageal tumor.

The laryngeal mask airway (LMA) can be used for gastroscopy, but its use can result in loss of the seal and/or displacement of the cuff. We describe an LMA that was specifically modified for gastroscopy and report its use in a patient with an esophageal tumor. The modified LMA has (a) a second tube that allows instruments to be directed toward the esophagus and (b) a second cuff mounted on the dorsal surface that increases the efficacy of the seal with the larynx. A 78-year-old man weighing 65 kg presented with a large mediastinal adenocarcinoma that was infiltrating the lateral wall of the thoracic esophagus. An esophagoscopy under anesthesia was planned to debulk the tumor. The modified LMA was inserted easily following induction with propofol. Anesthesia was maintained with propofol and 50% O2 in air and spontaneous ventilation. A lubricated 10.5-mm external diameter gastroscope was inserted into the second tube and passed easily into the esophagus. The tumor was successfully debulked using a polypectomy snare and an argon plasma coagulator. There was no loss of seal or displacement of the cuff, and the patient was stable throughout the procedure. We conclude that gastroscopy is feasible with the modified LMA. The device has a potential application in patients who require ventilatory support during gastroscopy.

Aged↗
PubMed2001

Routine use of the intubating laryngeal mask airway results in increased upper airway morbidity.

PURPOSE: The classic laryngeal mask airway (LMA) has a soft, silicone tube and the intubating laryngeal mask airway (ILM) has a rigid, silicone-coated steel tube. We compare postoperative pharyngolaryngeal morbidity in patients randomised to receive either device. METHODS: Sixty-five female patients (ASA physical status class I or II, aged 18-80 yr) undergoing balanced regional anesthesia for gynecological laparotomy expected to last one to two hours were randomly assigned for airway management with the LMA or ILM. Intracuff pressure was maintained at 60 cm H20. Postoperative pharyngolaryngeal morbidity (sore throat, difficulty swallowing, sore mouth, sore neck/jaw, hoarseness) was assessed at two, 24 and 48 hr by blinded investigators. RESULTS: The number of insertion attempts and duration of anesthesia was similar between groups. Sore throat was more common for the ILM at two hours (44 vs 15%, P=0.01), 24 hr (59 vs 21%, P=0.008) and 48 hr (34 vs 3%, P=0.005). Sore mouth was more common for the ILM at two hours (16 vs 0%, P=0.02) and 24 hr (12 vs 0%, P=0.04), but not at 48 hr (6 vs 3%). Difficulty swallowing was more common for the ILM at two hours (25 vs 0%, P=0.04), but not at 24 hr (31 vs 3%) and 48 hr (12 vs 9%). There were no differences in the incidence of sore jaw/neck (ILM, 3-12%; LMA, 0-3%) and hoarseness (ILM, 12-31%; LMA, 16-18%). There was no correlation between postoperative pharyngolaryngeal morbidity and duration of anesthesia. CONCLUSION: Pharyngolaryngeal morbidity is more common with the ILM than the LMA following anesthesia lasting one to two hours.

Adolescent↗
PubMed2001

[Spontaneous versus controlled respiration with the laryngeal mask. A review].

Over the last 10 years, the Laryngeal Mask Airway (LMA) has gained widespread acceptance as a general purpose airway for routine anaesthesia. Published data from large studies and reports have confirmed the safety and efficacy of the device for spontaneous and controlled ventilation during routine use. The initial experience with the LMA should ideally be confined to short cases requiring the patient to remain spontaneously ventilating. With experience, it will be found that less anesthetic agent is required during anesthesia with the LMA and patient recovery should be improved as a result. Spontaneous breathing is the chosen mode of ventilation in approximately 60% of LMA uses in the UK. During spontaneous breathing a minimal inspiratory pressure support will help with higher endtidal carbon dioxide levels. The anaesthetist should be experienced with using the LMA in spontaneously ventilating patients before using it with positive pressure ventilation. Several large scale studies have failed to show any link between positive pressure ventilation and pulmonary aspiration or gastric insufflation. The main disadvantage of the LMA is that it does not protect against aspiration. From a practical point of view, most fasted patients with normal lung compliance may be mechanically ventilated through the LMA to airway pressures of approximately 20 cmH2O. The low pressure seal implies that tidal volumes should be approximately 6-8 ml*kg-1 and the inspiratory flow rates should be reduced to achieve adequate and safe ventilation.

Anesthesia, Inhalation↗
PubMed2001

A comparison of four methods for assessing oropharyngeal leak pressure with the laryngeal mask airway (LMA) in paediatric patients.

BACKGROUND: This study compares four tests for assessing oropharyngeal leak pressure with the laryngeal mask airway (LMA). We tested the hypothesis that the oropharyngeal leak pressure and interobserver reliability differs between tests. METHODS: Eighty paralysed anaesthetized paediatric patients (weight 10-30 kg) were studied with the intracuff pressure set at 60 cmH2O. Four different oropharyngeal leak pressure tests were performed in random order on each patient by two observers blinded to each other's measurements. Test 1 involved detection of an audible noise. Test 2 involved detection of endtidal CO2 in the oral cavity. Test 3 involved observation of the aneroid manometer dial as the pressure increased and noting the airway pressure at which the dial reaches stability. Test 4 involved detection of an audible noise by neck stethoscopy. RESULTS: The mean oropharyngeal leak pressure was 12.5 cmH2O and was similar between tests. The intraclass correlation coefficient was 0.99 for all tests and was classed as excellent. CONCLUSIONS: We conclude that all four tests provide accurate and reliable information about oropharyngeal leak pressure in children.

Air Pressure↗
PubMed2001

Resting esophageal sphincter pressures and deglutition frequency in awake subjects after oropharyngeal topical anesthesia and laryngeal mask device insertion.

UNLABELLED: We investigated the effects of oropharyngeal topical anesthesia and placement of the standard (LMA) and the ProSeal (PLMA) laryngeal mask airway on resting gastroesophageal barrier pressure (GEBP), upper esophageal sphincter pressure (UESP), and deglutition frequency in awake subjects. Each subject was studied on 2 consecutive days: 1 day with the LMA and the other with the PLMA, in random order. GEBP and UESP were measured between deglutitions by using a pull-through technique in five sequential conditions: 1) after acclimatization to the manometer, 2) after topical anesthesia, 3) after the LMA or PLMA was self-inserted and the cuff inflated with either 10 or 30 mL of air in random order, 4) after the cuff volume was adjusted to the other randomized volume, and 5) after LMA or PLMA removal. Deglutition frequency was determined between pressure measurements by using a neck microphone. UESP was always larger than GEBP (P < 0.001 for all). Topical anesthesia had no influence on GEBP, UESP, or deglutition frequency. LMA and PLMA placement did not influence GEBP or UESP, but deglutition frequency was higher (P < 0.02 for all). GEBP and UESP did not vary between devices for any condition. Cuff volume did not influence GEBP or UESP. Deglutition frequency was more frequent for the LMA than the PLMA at a 30-mL cuff volume (P = 0.008). We conclude that resting GEBP and UESP are unaffected by oropharyngeal topical anesthesia and the LMA or PLMA in awake subjects, but that deglutition frequency is increased by the LMA or PLMA. This may have implications for the incidence of regurgitation in these situations. IMPLICATIONS: Resting gastroesophageal barrier pressure and upper esophageal sphincter pressure are unaffected by oropharyngeal topical anesthesia and laryngeal mask devices in awake subjects, but deglutition frequency is increased by laryngeal mask devices. This may have implications for the incidence of regurgitation in these situations.

Administration, Topical↗
PubMed2001

Blind orotracheal intubation with the intubating laryngeal mask versus fibreoptic guided orotracheal intubation with the Ovassapian airway. A pilot study of awake patients.

In a randomized, prospective pilot study, we compared awake blind orotracheal intubation using the intubating laryngeal mask airway (blind-ILM) with awake fibreoptic-guided orotracheal intubation using an Ovassapian airway (FOS-OA). Fifty-four patients (ASA 1 to 3, aged 18 to 85 years) requiring awake intubation for elective surgery were randomly allocated by coin toss into two groups: 31 patients were intubated blindly through the ILM (blind-ILM) and 23 were intubated using fibreoptic guidance through the Ovassapian airway (FOS-OA). Sedation to a target clinical end-point (spontaneous eye-closing, but responsive to verbal command) was obtained with fentanyl/midazolam and a cricothyroid puncture was performed with 3 ml lignocaine 4%. The oropharynx was then topicalized until tolerance of a Guedel airway was achieved. The number of failed attempts (maximum of three allowed), overall success rates, the time from insertion of the airway to capnographic (blind-ILM) or fibreoptic (FOS-OA) confirmation of intubation or until three failed attempts, and cardiovascular responses before and during intubation, were recorded. The first time (blind-ILM, 25/31 [81%]; FOS-OA, 20/23 [87%], P = 0.6) and overall (blind-ILM, 26/31 [84%]; FOS-OA, 22/23 [96%], P = 0.2) intubation success rates were similar. The mean +/- SD time to intubation was shorter for the blind-ILM group (104 +/- 65 vs 158 +/- 115 sec, P = 0.05). There were no clinically significant differences in blood pressure or heart rate between groups. Compared with baseline values, there was no cardiovascular response to intubation in either group. We conclude that the blind-ILM and FOS-OA techniques have similar success rates and cardiovascular responses, but intubation is slightly quicker with the blind-ILM technique.

Adult↗
PubMed2001

Airway protection with the ProSeal laryngeal mask airway.

The ProSeal laryngeal mask airway is a new laryngeal mask device that has a modified cuff and a drainage tube. We describe a case where the ProSeal laryngeal mask successfully channelled regurgitated fluid away from the respiratory tract.

Equipment Design↗
PubMed2000

Successful pharyngeal pulse oximetry in low perfusion states.

PURPOSE: We describe pharyngeal oximetry with the laryngeal mask airway in two patients with low perfusion states where finger oximetry failed. CLINICAL FEATURES: One patient was a 47-yr-old man with septic shock and the other a 64-yr-old man with multiorgan failure. In both patients, a # 4 laryngeal mask airway with a pediatric pulse oximeter probe was inserted behind the tracheal tube. A good waveform was obtained and oxygen saturation was 0-2% lower than arterial samples. CONCLUSION: Pharyngeal oximetry with the laryngeal mask airway is feasible in low perfusion states when finger oximetry fails.

Humans↗
PubMed2000

Does efficacy of seal and fibreoptic view change during anaesthesia with the laryngeal mask airway: a comparison of oxygen and oxygen-nitrous oxide gas mixtures.

BACKGROUND: We test the hypothesis that oropharyngeal leak pressure (OLP) and fibreoptic position (FP) are stable for the laryngeal mask airway (LMA) during anaesthesia with and without nitrous oxide. METHODS: Forty paralysed anaesthetised patients (ASA 1-2, aged 18-80) were randomly allocated to receive 100% oxygen (O2 group) or 33% oxygen in nitrous oxide (O2-N2O group) for maintenance. In vivo intracuff pressure (CP) using a size 5 LMA was adjusted to 60 cm H2O. OLP, FP and CP were measured every 5 min for 30 min. RESULTS: CP was higher in the O2-N2O group than the O2 group, other than at time zero (all: P<0.0001). CP increased every 5 min in the O2-N2O group (all: P<0.0001), but not in the O2 group. There were no differences in OLP and FP between groups at any time. There were no significant changes in OLP or FP with time within each group. There were no changes in OLP greater than 1.5 cm H2O and no change in FP for any patient. CONCLUSION: We conclude that OLP and FP are stable for the LMA during anaesthesia lasting 30 min with or without nitrous oxide.

Adolescent↗
PubMed2000

Emergence characteristics and postoperative laryngopharyngeal morbidity with the laryngeal mask airway: a comparison of high versus low initial cuff volume.

In this study we tested the hypothesis that the initial cuff volume of the laryngeal mask airway influences emergence characteristics and postoperative laryngopharyngeal morbidity. One hundred and sixty adult patients undergoing minor surgery were randomly assigned for airway management with the laryngeal mask airway with either a fully inflated cuff (LMA-High) or a semi-inflated cuff (LMA-Low). Anaesthesia was with propofol, nitrous oxide, oxygen and isoflurane. Following insertion, the cuff was inflated with either 15 or 30 ml for the size 4 (females) and 20 or 40 ml for the size 5 (males). At the end of surgery, a blinded observer documented the presence or absence of adverse airway events (hypoxia, hypercapnea, coughing, retching, regurgitation/vomiting, airway obstruction, hypoventilation, hiccupping, biting, body movement or shivering) during every 1 min epoch and cardiorespiratory variables (heart rate, mean blood pressure, arterial oxygen saturation, end-tidal carbon dioxide and respiratory rate) every 5 min until the patient was awake and the laryngeal mask airway removed. Patients were interviewed about pharyngolaryngeal morbidity (sore throat, dysphonia and dysphagia) immediately before leaving the postanaesthesia care unit and 18-24 h following surgery. Analysis by epoch showed more partial airway obstruction in the LMA-High group, but analysis by patient numbers revealed no difference. Heart rate was slightly higher in the LMA-High group upon arrival in the postanaesthesia care unit, but otherwise there were no differences in cardiorespiratory responses. Sore throat and dysphagia were more common in the LMA-High group. We conclude that, in general, emergence characteristics with the laryngeal mask airway are not influenced by the volume of air used to inflate the cuff, but that postoperative sore throat and dysphagia are more likely at high initial cuff volumes.

Adolescent↗
PubMed2000

Haemodynamic responses to the intubating laryngeal mask and timing of removal.

We determined (a) the haemodynamic responses to intubating laryngeal mask (ILM) airway insertion/intubation and removal in anaesthetized patients, and (b) whether the timing of ILM removal influences these responses. One-hundred and twenty patients without cardiovascular disease were studied. ILM airway insertion/intubation was 5 min after induction with propofol 2 mg kg(-1) and maintenance of anaesthesia with sevoflurane 2% in oxygen 33% and nitrous oxide. Patients were randomly assigned for removal of the intubating laryngeal mask airway at 1, 3 and 5 min after successful intubation. Systolic and diastolic arterial pressures and heart rate were recorded preinduction (baseline), before ILM airway insertion/intubation, at 1-min intervals after insertion/intubation, and at 1-min intervals for 5 min after ILM removal. ILM insertion was successful at the first attempt in all patients, but 46 patients required more than one intubation attempt. Compared with baseline values, there were no increases in systolic or diastolic arterial pressure, but there was an increase in heart rate 1 min after ILM insertion/intubation (9%, P<0.001) and 1 min after ILM removal (8%, P<0.01). There was a significant increase in systolic and diastolic pressures and heart rate 1 min after ILM insertion/intubation (30%, 31% and 15%; all: P<0.002) compared with before ILM insertion/intubation values and 1 min after ILM removal (9%, 8% and 7%; all P<0.05) compared with 1 min after ILM insertion/intubation values. Removal of the ILM 1 min after successful intubation resulted in higher arterial pressure compared with removal at 3 min (systolic arterial pressure 10% higher for 1 min, P = 0.01) and 5 min (systolic arterial pressure 10-23% higher for 3 min, P<0.01; diastolic arterial pressure 10-20% higher for 4 min, P>0.02), but there were no differences in heart rate between groups. Systolic and diastolic arterial pressures were greater if more than one intubation attempt was required. Early removal or multiple intubation attempts did not exceed baseline haemodynamic values. We conclude that ILM insertion/intubation and removal in anaesthetized patients produces little or no haemodynamic response, even if multiple intubation attempts are required. The timing of removal exerts a small, but clinically unimportant influence on these responses.

Adult↗
PubMed2000

Performance of the size 5 laryngeal mask airway in males and females.

We compare the functional performance (ease of insertion, oropharyngeal leak pressure and anatomic position) of the size 5 LMA in males and females over a range of cuff volumes. We also determine 1) if age, height, weight and body mass index predict functional performance and 2) the relationship between oropharyngeal leak pressure (OLP) and anatomic position (judged by fibreoptic scoring). One hundred male and one hundred female paralysed, anaesthetised patients were studied. The number of insertion attempts and time to placement were recorded. OLP and fibreoptic score (FOS) were measured during inflation of the cuff from 0-40 ml in 10 ml increments. There were no failed insertions. Insertion times were similar for males and females. There were no differences in OLP or FOS between males and females at any cuff volume. For males, OLP increased from 0 to 10 ml and 10 to 20 ml (p < 0.001), but was unchanged from 20 to 30 and 30 to 40 ml. For females, OLP increased from 0 to 10 ml, 10 to 20 ml (p < 0.001) and decreased from 20 to 30 ml (p = 0.02), but was unchanged from 30 to 40 ml. For males, FOS increased from 0 to 10 ml (p = 0.02) and 10 to 20 ml (p < 0.001), but was unchanged from 20 to 30 and 30 to 40 ml. For females, FOS increased from 0 to 10 ml (p = 0.02), 10 to 20 ml (p < 0.001), decreased from 20 to 30 ml (p = 0.001), but was unchanged from 30 to 40 ml. There was a significant positive correlation with height and OLP in males and females at higher cuff volumes, but no correlation with any other variable. There was no correlation between OLP and FOS at any cuff volume for males, but there was a correlation at 0 (p = 0.03) and 10 ml (p = 0.01) for females. We conclude that ease of insertion, efficacy of seal and anatomic position for the size 5 LMA is similar in males and females. Age, weight and body mass index do not predict performance, but efficacy of seal improves with increasing patient height. Fiberoptically determined anatomic position is a poor predictor of efficacy of seal. The shape of the pharynx may be different between tall and short adults.

Adult↗
PubMed2000

A fibreoptic scoring system to assess the position of laryngeal mask airway devices. Interobserver variability and a comparison between the standard, flexible and intubating laryngeal mask airways.

We determined the interobserver reliability of a fibreoptic scoring system for assessing the position of the laryngeal mask airway (LMA), the flexible laryngeal mask airway (FLMA) and the intubating laryngeal mask airway (ILM). We also compare fibreoptic position between the devices. Thirty anaesthetised adult patients were studied in random order in a triple crossover manner. Two observers blinded to each others findings scored the fibreoptic position as follows: 4, only vocal cords visible; 3, vocal cords plus posterior epiglottis visible; 2, vocal cords plus anterior epiglottis visible; 1, vocal cords not seen. Interobserver reliability was examined using intraclass correlation coefficient (ICC). Interobserver reliability was graded as excellent for the LMA (ICC = 0.89), FLMA (ICC = 0.87) and ILM (ICC = 0.79). Fibreoptic scores were higher for the LMA and FLMA compared with the ILM (both p < 0.001). We conclude that interobserver reliability for the fibreoptic scoring system is excellent for the LMA, FLMA and ILM. Fibreoptic position is better for the LMA and FLMA compared with the ILM. Fibreoptic scoring has potential utility for research and clinical practice with laryngeal mask devices.

Adult↗