The LMA CTrach for awake intubation combines the features of the LMA Fastrach and the fiberoptic bronchoscope, but cannot replace this combination in all patients.
Explore the source record for details and available documents.
Airway Obstruction↗
Biomedical subjects
M S Kristensen
Publications and source records attributed to M S Kristensen.
Qualitative analysis of unanticipated difficult airway management.
BACKGROUND: Unanticipated difficult airway management (DAM) is a major challenge for the anaesthesiologist and is associated with a risk of severe patient damage. We analysed 24 cases of unanticipated DAM for actual case management and anaesthesiologists knowledge, technical and non-technical skills. Anaesthesiologists' opinions, as well as environmental factors of importance for DAM proficiency, were also assessed. METHODS: Departments of Anaesthesiology in three Copenhagen University Hospitals participated in a prospective study of unanticipated DAM. Anaesthesiologists recorded the details of the cases on a data sheet. Qualitative data were collected in a semi-structured interview if the value of the Intubation Difficulty Score (IDS) was more than five, if the value of the visual analogue scale score for mask ventilation was more than five or in the case of a registered complication. Transcripts were theme analysed independently by two analysts. Data sheets and interviews were used in the final evaluation. RESULTS: All 24 cases concerned difficult tracheal intubation, and this was associated with difficult mask ventilation on four occasions. Management in three cases demonstrated strict adherence to a DAM practice guideline. Anaesthesiologists lacked standards for DAM. Inadequate knowledge, training and training facilities were documented. Sudden re-allocation of personnel and change of anaesthetic technique were potential risk factors for DAM. Insufficient airway assessment, insufficient patient information and registration of difficulties were demonstrated. Ethical issues were raised concerning the use of patients for skills practice. CONCLUSIONS: Both personal and system failures resulted in unanticipated DAM. There was insufficient knowledge of DAM and anaesthesiologists lacked DAM training. Standards for DAM and curricula for continuing education in DAM are needed.
Anesthesia, General↗
Decreased tongue mobility -- an explanation for difficult endotracheal intubation?
Established parameters predictive of difficulty in airway management were inconclusive in five ear, nose and throat (ENT) patients. All presented with degrees of tongue fixation - restriction of movement. Initially, experienced anaesthetists concluded that conventional endotracheal intubation would present no problems. Later, there were adjustments to this conclusion, with the ultimate being that four of the patients underwent fibre-optic intubation: one electively, two after repeated failed conventional attempts and one after a failed attempt of retrograde intubation. The last patient underwent elective retrograde intubation. All intubations were performed uneventfully in anaesthetized or sedated patients under spontaneous respiration. We found that tongue fixation was a direct cause of failed conventional endotracheal intubation, and recommend that a detailed tongue status investigation should be routine during Mallampati evaluation. Any abnormality should be seen as predictive of difficult/impossible conventional direct laryngoscopic intubation.
Aged↗
Tube tip in pharynx (TTIP) ventilation: simple establishment of ventilation in case of failed mask ventilation.
BACKGROUND: Mask ventilation occasionally fails. Alternative readily available and simple methods to establish ventilation in these cases are needed. METHODS: Retrospective description of cases in which a new technique, tube tip in pharynx (TTIP) ventilation, was employed for restoring ventilation in case of failed facemask ventilation during induction of anaesthesia. The technique involves a standard endotracheal tube and can be performed single-handed: A standard endotracheal tube was placed via the mouth with the tip in the pharynx and the cuff was inflated. By placing the fourth and fifth fingers below the ramus of the mandible, the third finger below the lower lip, the second finger above the upper lip and on one side of the nose and the first finger on the other side of the nose, an open airway is restored. Chin lift is inherent in the grip, thus contributing to opening of the airway. RESULTS: In all four cases of failed mask ventilation the anaesthetist could establish an open airway and subsequent ventilation without the need for an assistant. There were no indications of gastric insufflation. CONCLUSION: The TTIP technique established ventilation in all four patients after abandoned facemask ventilation. The technique only involves one person and an endotracheal tube and warrants to be included in the armamentarium of anaesthetists. Further prospective studies are needed to refine the technique and delimit its indications.
Adult↗
Inter-observer agreement of tests used for prediction of difficult laryngoscopy/tracheal intubation.
BACKGROUND: Guidelines recommend pre-operative airway evaluation for the prediction of airway management difficulties. Combining tests for evaluation increases the accuracy of the assessment. One model including seven parameters transformed into a simplified airway risk index (SARI) has been proven to be valid. We determined the inter-observer agreement of the specific test combinations included in SARI as well as of the total score. METHODS: Four observers assessed 136 patients, 120 without and 16 with a difficult airway history. Two residents and two specialists in anaesthesia performed the airway assessment consisting of the measurement of the mouth opening, the thyromental distance (TMD), the ability to protrude the mandible and an evaluation of the Mallampati class and head and neck mobility. Body weight was also recorded. Inter-observer agreement between specialists and residents, separately, was analysed using kappa statistics and Spearman's correlation analysis and the limits of agreement were evaluated using the 95% confidence interval. The agreement between pairs of assessors was also evaluated. RESULTS: The inter-observer agreement was good to excellent for both specialists and residents when measuring mouth opening (Spearman's correlation coefficient R=0.88-0.97) and the horizontal distance between the upper and lower incisors during jaw protrusion (R=0.56-0.97). The Mallampati classification assessment demonstrated satisfactory to complete inter-observer agreement (kappa=0.41-1). The assessment of TMD and neck mobility showed considerable discrepancies between observers. CONCLUSIONS: We demonstrated good inter-observer agreement using three tests from SARI and recommend the Mallampati classification, mouth opening and ability of jaw protrusion for pre-operative airway evaluation. A simplification of the assessment of TMD and neck mobility is warranted.
Adult↗
Evaluation of the airway of the SimMan full-scale patient simulator.
BACKGROUND: SimMan is a full-scale patient simulator, capable of simulating normal and pathological airways. The performance of SimMan has never been critically evaluated. METHODS: Sixty subjects (anesthesiologists, nurse anesthetists, and anesthesia residents) performed mask ventilation, laryngeal mask insertion and endotracheal intubation on SimMan. The simulator's airway was evaluated using visual analog scales (VAS) and by measuring the subject's performances. RESULTS: The SimMan full-scale patient simulator's airway is generally acceptably realistic but it significantly differs from the human airway in important aspects. Mask seal was more difficult than in humans whereas Laryngeal mask (LMA) insertion and function was acceptable. The distance from the teeth to the vallecula was too short. Cervical spine mobility was significantly reduced in the 'reduced neck movement' mode but the intubation was only slightly more difficult than in the 'normal' mode. CONCLUSION: The SimMan full-scale patient simulator's airway is generally acceptably realistic but it significantly differs from the human airway in important aspects. The user must be aware of these aspects in order to obtain maximum benefit from training and evaluation scenarios and when using the simulator for testing new equipment and techniques.
Anesthesiology↗
Residents lack knowledge and practical skills in handling the difficult airway.
BACKGROUND: Full-scale simulators have been developed in anaesthesia. We aimed at assessing Danish anaesthesia residents' knowledge and management of a standardized difficult airway situation in an advanced airway simulator. The reliability of the assessment was also determined. METHODS: Thirty-six residents answered a questionnaire testing their knowledge on difficult airway management and practice patterns. Secondly, all residents attempted management of a standardized 'cannot ventilate, cannot intubate' airway scenario. Three observers independently assessed a video recording of the performance. RESULTS: Only 17% of the residents passed the written test. Ninety-seven per cent stated that they had difficulties recalling the American Society of Anesthesiologists'(ASA) difficult airway algorithm and 53% did not know how to oxygenate through the cricothyroid membrane. Seventeen per cent had previously been involved in emergency situations with severe complications due to insufficient airway management. In the scenario 75% of the residents established ventilation using a laryngeal mask airway. After establishing ventilation, 26% would continue with surgery without a definitive airway, despite the risk of aspiration. Analysis of the interobserver agreement showed good (Kappa = 0.63) to excellent (Kappa = 0.78) consistency for objective parameters in the scoring scheme. Inter-observer reliability was satisfactory (R = 0.43) for trained Crisis Resource Management evaluators. CONCLUSIONS: Theoretical and practical education in difficult airway management needs to be improved among Danish anaesthesia residents. Simulator assessment should only be performed using well-defined objective parameters and trained assessors.
Anesthesia, Inhalation↗
Anaesthesiological airway management in Denmark: assessment, equipment and documentation.
BACKGROUND: Failed intubation remains one cause of anaesthesia-related morbidity and mortality. In a recent survey in Denmark, 20% of respondents reported preventable mishaps in airway management. METHODS: Assessment of the airway, and its documentation, as well as the availability of various equipment to manage a difficult airway, and the existence of a failed intubation plan were surveyed by mailing a questionnaire to the clinical directors of all 69 anaesthesia departments in Denmark. RESULTS: Fifty-six departments (81%) returned the questionnaire. Pre-operative airway evaluation is performed in 90% of the departments. The tests included the mouth-opening test (77%), Mallampati score (48%), lower jaw protrusion (34%), neck mobility (63%), the measurement of the thyromental (11%) and sternomental distance (4%). The result of the tests are documented by 38% of the departments in the anaesthetic chart (96%), in the record (54%), on a card given to the patient (23%), in a letter sent to the patient's general practitioner (2%) or in a database (13%). The patients are personally informed in 82% of the departments. Only 54% of the departments have a failed intubation plan readily available. CONCLUSION: The preoperative assessment of the airways and its documentation is still unsatisfactory, as is communicating with the patient after a case of a difficult/impossible intubation. The adoption of internationally recognized recommendations might improve airway management and teaching to the best standard possible in the already well-equipped Danish anaesthetic departments.
Algorithms↗
Airway management behaviour, experience and knowledge among Danish anaesthesiologists--room for improvement.
BACKGROUND: Problems with managing the airways in relation to anaesthesia causes severe morbidity and mortality. A large proportion of these adverse respiratory events is preventable. Still patients continue to die from airway disasters related to anaesthesia, also in Scandinavia. The goal of this study is to identify which efforts are likely to improve this situation. METHODS: A questionnaire asking about experience, behaviour and availability of various items of equipment was mailed to all members of the Danish Society of Anaesthesiologists and were returned anonymously. RESULTS: More than 65% of respondents have sufficient access to a flexible fibrescope, but still 17% of specialists have no access and the vast majority (>67%) has little (1-10 times) or no experience in its use for awake intubation. A total of 52-70% knew the basic principles of the ASA difficult airway algorithm, but despite this only 25-50% would perform awake intubation if a difficult intubation was expected. More than 20% of respondents had experienced preventable airway management mishaps. In all, 18-46% did not know how to oxygenate via the cricothyroid membrane. CONCLUSION: There is room for improvement regarding airway management skills among Danish anaesthesiologists. It is likely that airway management can be improved by: A) Better knowledge of an appropriate plan, algorithm, for airway management. B) Awake intubation used more often. C) More experience in fibreoptic intubation. D) All anaesthesiologists accepting that previous difficult intubation is an indicator of future difficulties. E) All anaesthesiologists knowing, and practising on manikins, how to oxygenate via the cricothyroid membrane. F) Always having a laryngeal mask airway immediately available when inducing anaesthesia.
Anesthesia↗
Pulse oximetry at fibre-optic bronchoscopy in local anaesthesia: indication for postbronchoscopy oxygen supplementation?
The requirement for supplementary oxygen (O2) after fibre-optic bronchoscopy (FOB) was evaluated by means of pulse oximetry in 34 patients (19 men) of median age 62 years (range 28-85) who had had a diagnostic FOB. The patients were allocated at random into two groups, each of 17 persons, which were comparable concerning sex, age and the dose of benzodiazepine (diazepam tablets 10 mg 1 h before FOB and midazolam 2-5 mg i.v. during FOB) used for premedication. Patients in group 1 had lower pulmonary function (FEV1, FVC as a percentage of predicted values) than patients in group 2 (P < 0.02). The oxygen saturation of the haemoglobin (SpO2) in the tip of the index finger was recorded continuously for 30 min after the administration of oral diazepam, during FOB and for 120 min after the FOB procedure. All patients received nasal O2 supplement 21 min-1 during FOB. After FOB, O2 was discontinued in group 1, while group 2 continued to receive O2 21 min-1 for 120 min. The incidence of hypoxaemic episodes (SpO2 < or = 90% for a period of a minimum of > or = 12 s) after oral diazepam, before FOB, was similar in the two groups, 35%. After FOB, the incidence of hypoxaemic episodes was 88% in group 1 and 41% in group 2 (P < 0.01). The cumulated duration of hypoxaemia after FOB was a median of 30 s (range 0-7140) in group 1 and a median of 0 s (0-156) in group 2 (P < 0.0001). Impaired lung function (FEV1 < 75% of predicted value) was a risk factor for hypoxaemia. Postbronchoscopy, O2 supplement should be administered to sedated patients with impaired lung function until the patients have fully recovered.
Adult↗
[Carbon monoxide poisoning].
Explore the source record for details and available documents.
Carbon Monoxide Poisoning↗
Hyaluronan and procollagen type III aminoterminal peptide in serum and bronchoalveolar lavage fluid from patients with pulmonary fibrosis.
Previous studies of the collagen synthesis markers hyaluronan (hyaluronic acid) (HA) and procollagen type III aminoterminal peptide (PIIINP) in pulmonary fibrosis have reported elevated levels in bronchoalveolar lavage fluid (BALF) and suggested an association with disease activity. The objective of the present study was to evaluate whether HA and PIIINP in BALF and serum (S) correlated with paraclinical markers of disease activity (chest X-ray profusion score, pulmonary function tests (FEV1, FVC, TLC, DLCO)) in patients with pulmonary fibrosis. The material comprised 27 patients with biopsy-proven pulmonary fibrosis (12 cryptogenic and 15 due to connective tissue diseases) and 24 control subjects with normal lung function. BAL was performed in the right middle lobe with 250 ml saline. HA and PIIINP were measured in the cell-free BALF supernatant and in serum. Patients had higher BALF-HA (mean 86 +/- 17 (SEM) micrograms/l) than controls (39 +/- 2 micrograms/l (p < 0.01)), higher BALF-albumin (124 +/- 24 mg/l) than controls (58 +/- 4 mg/l (p < 0.01)) and higher BALF/S-HA ratio (2.4 +/- 0.6) than controls (1.2 +/- 0.6 (p < 0.05)). There were no significant differences respecting BALF-PIIINP, S-HA, or S-PIIINP. Patients (n = 14) with progressive disease had higher BALF-HA, higher BALF-albumin, higher S-PIIINP, and higher S-immunoglobulins than those with stable disease, but the differences did not reach statistical significance. Smokers (n = 18) had lower BALF-HA, lower S-HA, lower S-PIIINP, lower S-immunoglobulins, and higher lung function tests than non-smokers, but the differences did not reach statistical significance. In patients, significantly positive correlations were found between BALF-HA and BALF-albumin, between BALF-PIIINP and BALF-albumin, and a significantly negative correlation between S-PIIINP and TLC. None of the BALF or serum markers correlated with chest X-ray profusion score or any of the other lung function measurements. It is concluded that disease activity may be associated with elevated HA and PIIINP levels. Smoking may influence the immunological processes in pulmonary fibrosis and may be a confounder in studies of these patients.
Adult↗
Hyaluronan and procollagen type III aminoterminal peptide in serum and bronchoalveolar lavage fluid in patients with pulmonary sarcoidosis.
The aim of this study was to evaluate whether markers of collagen synthesis, hyaluronan (HA) and procollagen type III aminoterminal peptide (PIIINP) in bronchoalveolar lavage fluid (BALF) and serum (S) were correlated to paraclinical markers of disease activity (S-ACE, S-IgG S-IgA S-calcium, chest X-ray (CXR) profusion score, pulmonary function tests (FEV1, FVC, TLC, DLCO)) in pulmonary sarcoidosis. The material comprised 48 patients with biopsy proven sarcoidosis (35 male, 13 female, median age 31 years) and 24 controls (16 male, 8 female, median age 60 years). BAL was performed in the right middle lobe with 250 ml saline. Patients had higher BALF-HA, mean 88 +/- 13 (SEM) micrograms/l, than controls, 39 +/- 2 micrograms/l (p < 0.01), higher BALF-albumin, 121 +/- 13 mg/l, than controls 58 +/- 4 mg/l (p < 0.01), and higher BALF/S-HA ratio, 3.35 +/- 0.51, than controls, 1.23 +/- 0.60 (p < 0.01). There were no significant differences for S-HA, BALF-PIIINP, or S-PIIINP. In patients significant correlations were found between BALF-HA, S-HA, and BALF-albumin; between S-HA and S-ACE; between BALF/S-HA and BALF-albumin; between CXR profusion score and S-HA, S-ACE, S-IgG, S-IgA, FEV1, FVC, TLC and DLCO. The results indicate that measurement of S-HA, BALF-HA, and BALF-albumin may be of value in the monitoring of disease in pulmonary sarcoidosis.
Adult↗
[Occupational exposure to blood among health personnel].
Explore the source record for details and available documents.
Blood↗
Expression of monocyte chemotactic and activating factor (MCAF) in skin related cells. A comparative study.
A significant proportion of the infiltrating cells in several inflammatory skin diseases, including psoriasis and allergic contact dermatitis, are monocytes. Additionally, it is known that the cytokine monocyte chemotactic and activating factor (MCAF) can be produced by several cell types present in the skin, suggesting a significant role for MCAF in the accumulation of monocytes during immunological and inflammatory skin reactions. We have recently developed a precise method for quantification of the amount of a specific mRNA species in a given sample and have used this technique to compare specific MCAF mRNA amounts in cultures of human keratinocytes, dermal fibroblasts, endothelial cells, and monocytes, after stimulation with interleukin 1 alpha (IL-1 alpha) for 6 h. Endothelial cells produced very high, monocytes and fibroblasts intermediate, and keratinocytes low amounts of MCAF mRNA. We have also performed time course studies of MCAF mRNA levels in the four cell types. Our findings suggest that the regulation of MCAF mRNA expression in these cells parallels the regulation of the lymphocyte and neutrophil chemotactic factor interleukin 8.
Cells, Cultured↗
Arterial pulse pressure and vasopressin release in humans during lower body negative pressure.
The hypothesis was tested that narrowing of arterial pulse pressure (PP) is a determinant of arginine vasopressin (AVP) release in humans. Six normal males completed a two-step lower body negative pressure (LBNP) protocol of -20 and -50 mmHg, respectively, for 10 min each. None of these subjects experienced presyncopal symptoms. Arterial plasma AVP and plasma renin activity (PRA) (at 2-min intervals) only increased subsequent to a decrease in PP (invasive brachial arterial measurements) and stroke volume (ultrasound Doppler technique, n = 4). Simultaneously, mean arterial pressure did not change. A selective decrease in central venous pressure and left atrial diameter (echocardiography, n = 4) at LBNP of -20 mmHg did not affect AVP or PRA, whereas arterial plasma norepinephrine increased (n = 4). During LBNP, significant (P < 0.05) intraindividual linear correlations were observed between log(AVP) and PP in four of the subjects with r values from -0.75 to -0.99 and between log(PRA) and PP in all six subjects with r values from -0.89 to -0.98. In conclusion, these results are in compliance with the hypothesis that narrowing of PP in humans during central hypovolemia is a determinant of AVP and renin release.
Adult↗
Healthcare workers' risk of contact with body fluids in a hospital: the effect of complying with the universal precautions policy.
OBJECTIVE: To test whether healthcare workers' knowledge of and compliance with the basic principle of the Universal Precautions policy (i.e., that all patients should be treated equally regarding contact with body fluids) influenced the rate of contact with patient blood. DESIGN: Survey based on anonymous questionnaires. SETTING: A 380-bed secondary and tertiary care hospital receiving emergency and elective patients. PARTICIPANTS: All employees having any contact with patients. Nine hundred one of 1,308 (69%) of the questionnaires were returned. RESULTS: Twelve percent of the respondents (95% confidence interval [CI95] = 10.0%-14.4%) had experienced any contact with patient blood in the week preceding their answer. Physicians had the highest rate of contact with blood followed by nurses. In the five groups--physicians, nurses, laboratory technicians and phlebotomists, nursing aides, and student nurses--contact with blood was less frequent in the subgroup that did know and comply with the basic principle of the Universal Precautions policy, compared with the subgroup that did not. When adding the results for the 5 groups, contact with blood was experienced by 91 of 571 (15.9%, CI95 = 13%-19%) of the personnel who did not know and comply with Universal Precautions. The personnel who did know and comply with Universal Precautions had a significantly lower (9 of 111 [8.1%], p < .05, CI95 = 3.8%-15%) rate of contact with blood. CONCLUSIONS: The healthcare workers who knew and complied with Universal Precautions had a significant lower rate of contact with patient blood than those who did not.
Blood↗
Carotid baroreflexes and plasma vasopressin in humans during head-up tilt.
To investigate the influence of carotid baroreflexes on plasma arginine vasopressin (AVP) in humans, eight healthy males underwent two sessions of passive head-up tilt to 60 degrees for 15 min each. During one of the sessions (sequence randomized), carotid baroreflexes were simultaneously stimulated by static neck suction of 23 +/- 1 mmHg during the whole period of head-up tilt. Only subjects who did not develop presyncopal symptoms during head-up tilt were included. Head-up tilt increased AVP significantly from 1.0 +/- 0.3 to 4.2 +/- 1.3 pg/ml (P less than 0.05). In contrast to this, AVP did not at any point in time increase significantly during head-up tilt when neck suction was applied. Plasma renin activity and heart rate were unaffected by neck suction, whereas mean arterial pressure and central venous pressure decreased. We conclude that the moderate but significant increase in plasma AVP during nonhypotensive head-up tilt is in part mediated by deloading of carotid baroreceptors induced by the acute fall in hydrostatic pressure at the level of the carotid sinus.
Adult↗