Anaesthesia
-
Randomized Controlled Trial
Use of hyaluronidase as an adjuvant to ropivacaine to reduce axillary brachial plexus block onset time: a prospective, randomised controlled study.
Hyaluronidase 100 IU/mL when added to ropivacaine speeds onset of axillary nerve blockade.
pearl -
The clinical value of the estimation of systolic pulmonary artery pressure, based on Doppler assessment of peak tricuspid regurgitant velocity using transoesophageal echocardiography, is unclear. We studied 109 patients to evaluate the feasibility of obtaining adequate Doppler recordings, and compared Doppler estimates with values measured using a pulmonary artery catheter in a subset of 33 patients. Tricuspid regurgitation was evaluated at the mid-oesophageal level at 0-120° using Doppler echocardiography. ⋯ Doppler estimates by transoesophageal echocardiography were within 10 mmHg and 15% of values recorded with the pulmonary artery catheter in 28/33 (75%) patients and 22/31 (55%) patients, respectively. In 7 (21%) patients, the echocardiographic Doppler measurement exceeded the measured systolic pulmonary artery pressure by more than 30%. Our study indicates that estimation of the systolic pulmonary artery pressure using transoesophageal Doppler echocardiography is not a reliable and clinically useful method in anaesthetised patients undergoing mechanical ventilation.
-
Emergency and difficult tracheal intubations are hazardous undertakings where successive laryngoscopy-hypoxaemia-re-oxygenation cycles can escalate to airway loss and the 'can't intubate, can't ventilate' scenario. Between 2013 and 2014, we extended the apnoea times of 25 patients with difficult airways who were undergoing general anaesthesia for hypopharyngeal or laryngotracheal surgery. This was achieved through continuous delivery of transnasal high-flow humidified oxygen, initially to provide pre-oxygenation, and continuing as post-oxygenation during intravenous induction of anaesthesia and neuromuscular blockade until a definitive airway was secured. ⋯ The rate of increase in end-tidal carbon dioxide was 0.15 kPa.min(-1). We conclude that THRIVE combines the benefits of 'classical' apnoeic oxygenation with continuous positive airway pressure and gaseous exchange through flow-dependent deadspace flushing. It has the potential to transform the practice of anaesthesia by changing the nature of securing a definitive airway in emergency and difficult intubations from a pressured stop-start process to a smooth and unhurried undertaking.
-
Randomized Controlled Trial Comparative Study
Simulation-based teaching versus point-of-care teaching for identification of basic transoesophageal echocardiography views: a prospective randomised study.
In recent years, the use of transoesophageal echocardiography has increased in anaesthesia and intensive care. We explored the impact of two different teaching methods on the ability of echocardiography-naïve subjects to identify cardiac anatomy associated with the 20 standard transoesophageal echocardiography imaging planes, and assessed trainees' satisfaction with these methods of training. Fifty-two subjects were randomly assigned to one of two groups: a simulation-based and a theatre-based teaching group. ⋯ Subjects in simulation- and theatre-based teaching groups scored 40% (30-40 [20-50])% and 35% (30-40 [15-55])% in the pre-test, respectively (p = 0.52). Following echocardiography teaching, subjects within both groups improved upon their pre-test knowledge (p < 0.001). Subjects in the simulation-based teaching group significantly outperformed their theatre-based group counterparts in the post-intervention test (p = 0.0002).
-
Cardiovascular autonomic neuropathy is frequently observed in patients with diabetes mellitus. As anaesthesia has a marked effect on peri-operative autonomic function, the interplay between diabetic neuropathy and anaesthesia may result in unexpected haemodynamic instability during surgery. The objective of this literature review was to examine the association of cardiovascular autonomic neuropathy with peri-operative cardiovascular complications. ⋯ Depending on the type of anaesthesia, the presence of cardiovascular autonomic neuropathy in surgical patients can markedly affect peri-operative haemodynamics and postoperative recovery. Pre-operative testing of the extent of autonomic dysfunction in particular populations, like diabetics, may contribute to a reduction in haemodynamic instability and cardiovascular complications. Non-invasive diagnostic methods assessing autonomic function may be an important tool during pre-operative risk assessment.