Mivacurium 0.2 mg/kg in Young (18 - 40 Years) and Elderly (= 80 Years) Patients

Study Overview
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Brief Summary
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The aim of this study is to determine the onset time, duration of action and effect on intubation conditions of mivacurium 0.2 mg/kg in elderly patients with age ≥ 80 years and in young patients aged 18 - 40 years.

Detailed Description
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The aim of this study is to determine the onset time, duration of action and effect on intubation conditions of mivacurium 0.2 mg/kg in elderly patients with age ≥ 80 years and in young patients aged 18 - 40 years. The hypothesis of this study is that mivacurium administered in elderly patients (>80 years) has a longer onset time and duration of action compared to younger patients.

Official Title
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An Observational Study of Mivacurium 0.2 mg/kg, Comparing Onset Time, Duration of Action and Effect on Intubating Conditions in Young (18 - 40 Years) and Elderly (= 80 Years) Patients

Conditions
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Onset Time of Mivacurium, Duration of Action of Mivacurium

Intervention / Treatment
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* Drug: Mivacurium


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients ≥ 80 or ≥ 18 to ≤ 40 years of age Informed consent Scheduled for elective surgery under general anaesthesia (expected duration of anaesthesia > 1 hour) with intubation and use of mivacurium American Society of Anesthesiologists (ASA) physical status classification I to III Can read and understand Danish Exclusion Criteria: Known allergy to mivacurium Neuromuscular disease that may interfere with neuromuscular monitoring Indication for rapid sequence induction Surgery in the prone position Known butyrylcholinesterase deficiency

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Elderly<br>patients aged 80 years or older | Drug: Mivacurium<br>* 0.2 mg/kg based on ideal body weight calculated as height (cm) minus 105 for women and height (cm) minus 100 for men or actual body weight, whichever is lower<br>* Other names: mivacron;|
| Young<br>patients aged 18-40 years | Drug: Mivacurium<br>* 0.2 mg/kg based on ideal body weight calculated as height (cm) minus 105 for women and height (cm) minus 100 for men or actual body weight, whichever is lower<br>* Other names: mivacron;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Onset time | the time from the start of the injection of mivacurium to train-of-four (TOF) count of 0 monitored by acceleromyography | within 10 minutes after administration of mivacurium | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Duration of action | Duration of action is defined as time from start of mivacurium injection to reappearance of TOF ratio > 0.9. | within 90 minutes after administration of mivacurium | 
| Intubation conditions IDS | intubation conditions are rated according to intubating difficulty score IDS when TOF-ratio is 0. | within 10 minutes after administration of mivacurium | 
| Intubation conditions Fuchs-Buder | intubation conditions are rated according to Fuchs-Buder score when TOF-ratio is 0. | within 10 minutes after administration of mivacurium | 
| Laryngeal morbidity | After 24 hours patients are asked about hoarseness and sore throat. Patients who experience either or both will be called 3 days postoperatively again. These two variables are assessed using a numeric ranking scale from 0 to 10. | 24 hours after surgery | 
| Amount of ephedrine or metaoxedrine administered | If ephedrine or metaoxedrine is administered after induction of anaesthesia and until the patient is ready for properly positioning for surgery, it will be noted in the CRF, as well as the amount administered. Changes in blood pressure or heart rate are treated according to local guidelines. | within 10 minutes after administration of mivacurium | 
| Butyrylcholinesterase activity in a venous blood sample | Butyrylcholinesterase activity in a venous blood sample, and further determination of phenotype and genotype if the activity is low. | within 7 days after administration of mivacurium |