Effects of using the simplified airway risk index vs usual airway assessment on unanticipated difficult tracheal intubation - a cluster randomized trial with 64,273 participants.

BACKGROUND: Unanticipated difficult intubation remains a challenge in anaesthesia. The Simplified Airway Risk Index (SARI) is a multivariable risk model consisting of seven independent risk factors for difficult intubation. Our aim was to compare preoperative airway assessment based on the SARI with usual airway assessment. METHODS: From 01.10.2012 to 31.12.2013, 28 departments were cluster-randomized to apply the SARI model or usual airway assessment. The SARI group implemented the SARI model. The Non-SARI group continued usual airway assessment, thus reflecting a group of anaesthetists' heterogeneous individual airway assessments. Preoperative prediction of difficult intubation and actual intubation difficulties were registered in the Danish Anaesthesia Database for both groups. Patients who were preoperatively scheduled for intubation by advanced techniques (e.g. video laryngoscopy; flexible optic scope) were excluded from the primary analysis. Primary outcomes were the proportions of unanticipated difficult and unanticipated easy intubation. RESULTS: A total of 26 departments (15 SARI and 11 Non-SARI) and 64 273 participants were included. In the primary analyses 29 209 SARI and 30 305 Non-SARI participants were included.In SARI departments 2.4% (696) of the participants had an unanticipated difficult intubation vs 2.4% (723) in Non-SARI departments. Odds ratio (OR) adjusted for design variables was 1.03 (95% CI: 0.77-1.38). The proportion of unanticipated easy intubation was 1.42% (415) in SARI departments vs 1.00% (302) in Non-SARI departments. Adjusted OR was 1.26 (0.68-2.34). CONCLUSIONS: Using the SARI compared with usual airway assessment we detected no statistical significant changes in unanticipated difficult- or easy intubations. CLINICAL TRIAL REGISTRATION: NCT01718561.

Perisciatic infusion of ropivacaine and analgesia after hallux valgus repair.

BACKGROUND: Moderate to severe pain after hallux valgus repair can be successfully treated with a continuous popliteal sciatic nerve block in ambulatory patients. Different anesthesiologists use various infusion rates for this purpose. The aim of this study was to compare the analgesic efficacy of two infusion rates of ropivacaine 2 mg/ml: 5 and 8 ml/h. METHODS: Forty ambulatory patients who underwent chevron osteotomy for hallux valgus were randomized to receive perisciatic infusion of ropivacaine 2 mg/ml at a rate of either 5 ml/h (5 ml group) or 8 ml/h (8 ml group). All patients received standard general anesthesia for surgery after the sciatic popliteal and the single-shot saphenus nerve blocks were performed. Verbal rating scale (VRS) scores for pain, sleep disturbances, opioid consumption and side effects were monitored for 3 post-operative days. RESULTS: No significant difference was found in the primary end point worst pain on the first post-operative day with VRS scores of 2.5 (0-8) vs. 5.5 (0-10) for the 5 and 8 ml/h groups, respectively (P=0.53). Post-operative pain was satisfactory in both groups, with an average VRS score ≤4 for 60-62 h. CONCLUSION: We found no significant difference in the analgesic effect between two perisciatic infusion rates of ropivacaine 2 mg/ml (5 vs. 8 ml/h) in ambulatory patients who underwent chevron osteotomy.

Depth of anaesthesia monitoring in obese patients: a randomized study of propofol-remifentanil.

BACKGROUND: In obese patients, depth of anaesthesia monitoring could be useful in titrating intravenous anaesthetics. We hypothesized that depth of anaesthesia monitoring would reduce recovery time and use of anaesthetics in obese patients receiving propofol and remifentanil. METHODS: We investigated 38 patients with a body mass index >or=30 kg/m(2) scheduled for an abdominal hysterectomy. Patients were randomized to either titration of propofol and remifentanil according to a cerebral state monitor (CSM group) or according to usual clinical criteria (control group). The primary end point was time to eye opening and this was assessed by a blinded observer. RESULTS: Time to eye opening was 11.8 min in the CSM group vs. 13.4 min in the control group (P=0.58). The average infusion rate for propofol was a median of 516 vs. 617 mg/h (P=0.24) and for remifentanil 2393 vs. 2708 microg/h (P=0.04). During surgery, when the cerebral state index was continuously between 40 and 60, the corresponding optimal propofol infusion rate was 10 mg/kg/h based on ideal body weight. CONCLUSION: No significant reduction in time to eye opening could be demonstrated when a CSM was used to titrate propofol and remifentanil in obese patients undergoing a hysterectomy. A significant reduction in remifentanil consumption was found.

[Ketamine as a broncholytic agent in status asthmaticus and as an anesthetic for patients with bronchial asthma]. / Ketamin som bronkiolytikum ved status asthmaticus og som anaestesimiddel til patienter med asthma bronchiale.

Ketamine was introduced into clinical anaesthesia in 1965. Since then it has been demonstrated to lower airway resistance and to increase lung compliance in the asthmatic patient. It has also proved useful in anesthetizing asthmatic patients with or without symptoms. In several case reports it has been used successfully in the management of status asthmaticus resistant to conventional therapy but so far no controlled clinical trial has been carried out to support this empirical use of ketamine. The limited magnitude of the side effects permits the use in status asthmaticus when all other treatment has failed. Experiments with animals and with human preparations have suggested one or more of the following mechanisms of action: a sympathomimetic effect, a direct relaxant effect, an antagonism to histamine and acetylcholine and a membrane stabilizing effect as with local analgesics. Until investigations have been published ketamine is recommended as an anaesthetic for the asthmatic patient and for the patient who has previously reacted with bronchospasm when intubated or anaesthetized. Prospective clinical trials should be planned.

[Aspiration of a coin after correct use of Rotahaler with Ventoline inhalation powder]. / Aspiration af mønt efter korrekt anvendelse af Rotahaler med Ventoline-inhalationspulver.

Rotahalers are widely used to administer Ventoline and Becotide. We report a case of inhalation of a coin from a rotahaler in a 71 year old asthmatic male and discuss prophylaxis.

[Hypertrophic tonsils as a cause of hypoxia and growth stagnation]. / Tonsilhypertrofi som årsag til hypoksi og vaegtstagnation.

A case is reported describing severe hypoxaemia and growth retardation in a child suffering from hypertrophic tonsils. A rapid increase in weight and length was demonstrated postoperatively and on clinical examination one year after tonsillectomy the child shows no signs of obstruction of the airways.

[Strategies to reduce the use of perioperative allogenic blood]. / Strategier til begraensning af det perioperative forbrug af allogent blod.

Allogenic blood transfusion carries the risk of immunological and non-immunological adverse effects. Consequently, blood transfusion should be limited to situations where alternatives are not available. This article reviews current by available alternative strategies that reduce the need for perioperative allogenic blood transfusion. The effectiveness of a number of these alternatives needs to be documented and potential adverse effects clarified. The acceptance of a lower haemoglobin level as the transfusion trigger value is perhaps the most important factor in reducing the need for peri-operative allogenic blood transfusion.

[Vestibular schwannoma. Incidence of the disease and the consequences]. / Vestibularis-schwannom. Sygdommens incidens og konsekvenser heraf.

During the period 1977-1996 142 vestibular schwannomas in 138 patients in a well-defined population in the County of Aarhus, Denmark were registered. The incidence of vestibular schwannomas changed from approximately six tumours pr. million inhabitants in the years 1977-1981 to 18 tumours pr. million in the period 1992-1996. Most tumours were operated, a smaller group of vestibular schwannomas were observed by repetitive tomographic imaging, due to small tumour size, advanced age, poor health conditions or the patient's refusal of operation. Whether the strategy for the treatment of vestibular schwannomas is an immediate operation or observation of selected patients, the future management of the increasing number of vestibular schwannomas will require an extension of the present surgical and MR-imaging capacity.

[Cardiac arrhythmias after transmediastinal resection of the esophagus]. / Kardiale arytmier efter transmediastinal resektion af esophagus.

A study of 45 patients who underwent blunt transmediastinal resection of the esophagus without thoracotomy is presented. Sixteen patients (38%) developed a cardiac arrhythmia. The most common arrhythmia was atrial fibrillation/flutter. Even though 14 of the arrhythmias (88%) converted to sinus rhythm, a significantly higher death-rate was seen in this group of patients (p < 0.0014). As we suspect a relation between cardiac arrhythmia and increased mortality after this type of operation, we propose that a double-blind study should be carried out in order to determine the value of an antiarrhythmic treatment.

[Acoustic neurinoma: observation prior to surgery]. / Acusticusneurinom: observation før operation.

During the period from 1977 to 1989 (both years included) 79 acoustic neurinomata were diagnosed in 76 patients in the County of Arhus. Twenty-four of these neurinomata were followed for varying periods clinically and radiographically. The symptoms of the patients and the results of successive computed-tomographic scans are mentioned. During the periods of observation, four patients were submitted to operation and operation was recommended in two cases. Seventeen patients are still under observation and are in good clinical condition with cessation or limited growth of the tumour in eight. These patients have been observed for between 1 and 13 years, on an average 4.5 years and are characterised by advanced age which averaged 61 years at the time of the diagnosis. The rate of growth of the tumour was calculated to be 1.1 mm per annum on an average with a variation from 0 mm to 4.8 mm per annum. As operative treatment of acouistic neurinoma exposes the patient to a not inconsiderable risk of deterioration the medical and/or socioeconomic status, the authors consider that an expectant and controlled attitude (wait and scan) is justified in elderly patients with acoustic neurinoma.

[Mortality after administration of human albumin to critically ill patients with hypovolemia. An analysis of a systematic Cochrane review]. / Mortalitet efter humant albumin hos kritisk syge patienter med hypovolaemi. En analyse af et systematisk Cochrane-review.

A systematic Cochrane review strongly suggested that the administration of human albumin to critically ill patients with hypovolaemia increases mortality. This review has been widely criticised and the aim of the present paper was to analyse the original studies with regard to 1) the randomisation procedure, 2) the blinding procedure, 3) the indication of treatment, 4) whether treatment was clearly defined and consistent, 5) how normovolaemia was defined, and 6) the length of the follow-up period. None of the twelve studies analysed fulfilled common criteria in relation to evidence-based medicine. Consequently, there is no scientific evidence to support the conclusion that human albumin administered to critically ill patients with hypovolaemia increases the mortality. Thus, the validity and quality control of systematic Cochrane reviews may be questioned.

[Pemphigus vulgaris and benign cicatricial mucous membrane pemphigoid in the upper respiratory tract and esophagus]. / Pemphigus vulgaris og benignt cikatricielt slimhindepemfigoid i øvre luftveje og esophagus.

Pemphigus vulgaris and benign cicatricial membrane pemphigoid are both autoimmune, blistering, dermatologic diseases characterised clinically by tense bullae on skin or on mucous membranes. Both diseases are rare, but very serious, associated with a high death rate (pemphigus) or high morbidity with cicatricial mucosal lesions (pemphigoid) if untreated. These diseases are discussed and two case stories mentioned where the primary focus was in the upper aerodigestive tract, which is very seldom. The otolaryngologist can make an important contribution to the early recognition, diagnosis, and management of these diseases. The biopsy must undergo immunofluorescence examination.

[Merkel cell carcinoma]. / Merkel-cellekarcinom.

Eight patients with Merkel cell carcinoma are reported to document their response to surgery and/or radiotherapy. Four patients who initially underwent surgery without postoperative radiation therapy all had local recurrence. Two patients were treated with postoperative radiation therapy and two were treated with radiation therapy without excision of the tumour. None of these four patients had local recurrence. Five patients developed regional recurrence. Recurrence was seen in one patient in the irradiated field. Metastatic disease was not seen in any case. These results combined with a review of the literature suggest that radiation therapy postoperatively to both the surgical bed and the draining lymph nodes may improve local regional tumour control.

[Acoustic neurinomas/vestibular schwannomas. Diagnostic evidence vs. surgery]. / Acusticusneurinomer/vestibularisschwannomer. Observation versus kirurgi.

+-f having vestibular schwannoma (VS) was conducted in a series of 123 patients (127 tumours), over a 20 year-period from 1973 to 1993. Mean follow up period was 3.4 years, mean annual growth rate was 3.2 mm/year. Tumour growth was observed in 90 patients (94 tumours, 74%), no growth was seen in 23 patients (23 tumours, 18%) and negative tumour growth in 10 patients (10 tumours, 8%). Surgery due to tumour growth was performed in 35 patients (35 tumours, 28%). Seven patients (seven tumours, 6%) were treated with gamma radiation and/or shunt insertion. Seven patients (6%) died of brainstem herniation induced by tumour compression. Nine patients (7%) died of non tumour related causes. Twenty-eight patients were classified as candidates for hearing preservation surgery and 21 patients (75%) lost their candidature during the observation period due to tumour growth and/or deterioration of hearing. The results may limit indications for allocation of patients with VS to the "wait and see" group.

Anaesthetic implications of long term diabetic complications.

A case history in which a patient suffering from long-term diabetes mellitus underwent vascular surgery of a lower extremity is presented. Anaesthesia was commenced with an epidural anaesthesia, but due to insufficient analgesia combined with a high thoracal block general anaesthesia was added. The course was complicated because of cardiomyopathy, autonomic neuropathy, difficult laryngoscopy, aspiration of gastric content, and acute renal failure. Anaesthetic implications of long-term diabetes mellitus are discussed.

Acoustic neuroma. Follow-up of 78 patients.

This study assesses the outcome in 78 patients who had been diagnosed with acoustic neuroma over a period of 13 years. Forty-six patients were treated with translabyrinthine surgery, 13 with suboccipital surgery and/or ventricular drainage, and 19 patients (20 neuromas) were kept under observation. Of the 59 patients who had surgery, four died, 30 had problems with eating, drinking and balance, 17 had severe facial palsy, 21 discontinued their work after the operation and 30 had psychological problems. Twenty neuromas have not been operated upon and the patients have not deteriorated medically or socially. It is concluded that acoustic neuroma is a serious disease and that a conservative policy (wait and scan) is preferable in elderly patients.

Tracheal administration of atropine in children--effect on heart rate.

Forty-one ASA I patients, aged 2-6 years, anaesthetized for elective ear, nose and throat surgery, were studied in a double blind and randomized fashion in order to examine the effect of tracheally administered atropine 0.02 mg.kg-1 or saline 0.9% on heart rate. In patients receiving atropine heart rate increased 8.8 beats.min-1 (8.7%) and 16.2 beats.min-1 (16.0%) after 3 and 5 min respectively. No increase in heart rate was seen in the saline group. Because of the late onset of action and only moderate increase in heart rate it is concluded that tracheal administration of atropine 0.02 mg.kg-1 to children is insufficient in emergency situations.

Anaesthetic implications of rigid spine syndrome.

The perioperative management of a 14-year-old girl, suffering from the muscular disorder rigid spine syndrome, is presented. The anaesthetic implications with regard to possible difficult intubation, cardiac involvement, malignant hyperthermia, neuromuscular blocking agents, and postoperative recovery are discussed.

Inhibition and induction of metronidazole and antipyrine metabolism.

The effect of cimetidine, antipyrine and phenobarbitone on the pharmacokinetics of intravenous metronidazole and oral antipyrine has been examined in 7 healthy volunteers. The administration of cimetidine for 24 h before and throughout the sampling period failed to alter the total clearance of metronidazole or the rate of formation of the hydroxy metabolite, whereas the total and partial clearances of antipyrine were decreased 0.74 and 0.6-0.7-fold, respectively. Seven days of phenobarbitone or antipyrine administration increased the total clearance of metronidazole 1.51- and 1.86-fold, respectively, and the total antipyrine clearance was 1.22 or 1.46-fold increased, respectively. The rate of metronidazole hydroxylation was significantly enhanced by both enzyme inducers. The partial clearance of antipyrine to the normetabolite was significantly increased by both inducers, whereas the rate of 4-hydroxylation was significantly increased only by prior antipyrine administration. The results indicate that the hydroxylation of metronidazole is not inhibited by cimetidine, but that it is inducible by phenobarbitone or antipyrine. It is suggested that metronidazole and antipyrine are metabolized by different enzymatic pathways.