Anaesthesia
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Epidural volume extension, a modification of combined spinal-epidural anaesthesia, involves the epidural injection of saline in order to increase the spread of drugs given intrathecally. Results from individual studies have so far been contradictory and we aimed to gather the available evidence for this technique. We performed a systematic literature search for randomised, controlled trials comparing epidural volume extension after spinal injection with a control group without epidural injection in patients undergoing surgery. ⋯ In summary, there is not enough evidence to draw definite conclusions on the effect of epidural volume extension. The quality of the current evidence is low for both efficacy (maximum sensory height) and safety (hypotension). However, there may be a significantly shorter motor block recovery time when different anaesthetic mixtures are used in epidural volume extension and control groups; this warrants further investigation.
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Inhalation of aerosolised medications are the mainstay of treatment for a number of chronic lung diseases and have several advantages over systemically-administered medications. These include more rapid onset of action for drugs such as β-adrenergic agonists when compared with oral medication, high luminal doses for inhaled antibiotics when used to treat endobronchial infection, and an improved therapeutic index compared with systemic delivery for these and other classes of drugs such as corticosteroids. The use of aerosolised drugs to treat patients whose tracheas are intubated is less well established, in part because systemic delivery via the intravenous route can be a simpler alternative for many drugs. ⋯ Although there have been some attempts to re-invigorate research in order to improve delivery systems, current devices are, to a great extent, based on long-standing technology developed more than 50 years ago. In this review, we explore current knowledge and provide guidance as to when and how the inhaled route may be of value when treating patients whose tracheas are intubated, and we set out the challenges facing those attempting to advance the topic. We conclude by reviewing current areas of interest that may lead to more effective and widespread use of aerosols in the treatment of intubated patients.
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Comparative Study
A comparison of gastric emptying of soluble solid meals and clear fluids matched for volume and energy content: a pilot crossover study.
We previously demonstrated that the gastric emptying time of different liquids with the same volume mainly depended on their energy content, regardless of differences in composition. In this crossover study, we investigated whether the same applies when soluble solid foods are ingested with water. Ten healthy volunteers ingested one of five test diets consisting of two test meals (Calorie Mate® 100 and 200 kcal) and three test solutions (water and glucose solutions of 100 and 200 kcal), each given in a volume of 400 ml, and then underwent ultrasonography to measure the gastric antral cross-sectional area every 10 min for 120 min. ⋯ The median (IQR[range]) gastric emptying times of Calorie Mate® of 100 kcal with water vs. isocaloric glucose solution were 65 (60-78 [50-80]) vs. 65 (60-70 [50-80]) min (p = 0.58), and for Calorie Mate® of 200 kcal with water vs. isocaloric glucose solution they were 100 (93-108 [90-120]) vs. 105 (90-110 [90-120]) min (p = 0.54). The median (IQR [range]) for water was 40 (30-40 [30-50]) min. Energy content may be a critical determinant of the gastric emptying time when ingesting soluble solid diets with water.
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Randomized Controlled Trial
Onset of labour epidural analgesia with low-dose bupivacaine and different doses of fentanyl.
This study investigated the effects of different doses of epidural fentanyl on the time to onset of epidural analgesia in women in early labour. We hypothesised that onset of epidural labour analgesia (the primary outcome defined as time in minutes from completion of epidural bolus to the first uterine contraction with a numeric pain rating scale [NPRS] score ≤ 3) would be faster with 100 μg of fentanyl epidural bolus compared with 20 μg or 50 μg. Epidural labour analgesia was initiated with 20 μg of fentanyl (F20 group), 50 μg (F50 group) or 100 μg (F100 group) along with 10 ml bupivacaine 0.08% as the loading dose. ⋯ This was not statistically significant (p = 0.16) comparing the F20 with the F100 group. There were no significant differences in maternal side-effects, mode of delivery, patient satisfaction scores or neonatal Apgar scores between all groups. We conclude that the 50 μg and 100 μg fentanyl doses were associated with reduced onset times to effective analgesia compared with the 20 μg dose.
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Observational Study
Ultrasound assessment of gastric contents in children undergoing elective ear, nose and throat surgery: a prospective cohort study.
Ultrasound examination of the gastric antrum allows reliable assessment of gastric contents and volume. Postoperative assessment of gastric contents before recovery from anaesthesia could help the physician to choose the most appropriate extubation technique after surgery in children. In this prospective observational study, we assessed whether significant changes occurred in gastric contents during the intra-operative period in children undergoing elective ear, nose and throat (ENT) surgery. ⋯ The mean (SD) gastric volume was 0.28 (0.30) ml.kg-1 before surgery and 0.27 (0.30) ml.kg-1 after surgery, p = 0.82. No solid contents were identified in the antrum, and the gastric volume was < 1.5 ml.kg-1 in all patients during both ultrasound examinations. Our results suggest that, after elective ENT surgery, children are not at risk of a full stomach before tracheal extubation, and that pulmonary aspiration of blood that may occur after elective ENT surgery is probably not related to regurgitation of ingested blood from the stomach.