British journal of anaesthesia
-
Case Reports
Thoracic paravertebral block: radiological evidence of contralateral spread anterior to the vertebral bodies.
We report contralateral spread of contrast medium anterior to the vertebral bodies after injection of contrast through a thoracic paravertebral catheter that was used to manage pain in a patient with multiple fractured ribs. We review the literature and propose that the anatomical basis for this observation is spread in the extrapleural compartment of the thoracic paravertebral space along the subserous fascial plane.
-
We have assessed the feasibility of retrograde nasotracheal intubation using a flexometallic tracheal tube with a detachable pilot balloon and connector in a study of 20 consecutive adult patients undergoing oropharyngeal surgery. The technique consisted of: (1) laryngoscope-guided orotracheal intubation; (2) insertion of an 18-gauge Foley catheter through the nose and retraction into the mouth; (3) detachment of the anaesthesia circuit, pilot balloon and connector; (4) insertion of the Foley catheter tip into the proximal end of the tracheal tube and inflation of the Foley catheter cuff; (5) withdrawal of the Foley catheter and attached tracheal tube back through the nose; (6) deflation of the Foley catheter cuff; and (7) re-attachment of the pilot balloon, connector and anaesthesia circuit. The technique was successful at the first attempt in all patients. ⋯ Nasal bleeding, airway problems and hypoxic events did not occur. No anatomical abnormalities or nasal trauma were detected at rhinoscopy. We conclude that retrograde nasotracheal intubation is feasible using a flexometallic tracheal tube with a detachable pilot balloon and connector.
-
Comparative Study
Biologically variable ventilation prevents deterioration of gas exchange during prolonged anaesthesia.
We have studied the time course of changes in gas exchange and respiratory mechanics using two different modes of ventilation during 7 h of isoflurane anaesthesia in pigs. One group received conventional control mode ventilation (CV). The other group received biologically variable ventilation (BVV) which simulates the breath-to-breath variation in ventilatory frequency (f) that characterizes normal spontaneous ventilation. ⋯ The modulation file used to control the ventilator for BVV used an inverse power law frequency distribution (I/fa with a = 2.3 +/- 0.3). After 7 h, at a similar delivered minute ventilation, significantly greater PaO2 (mean 72.3 (SD 4.0) vs 63.5 (6.5) kPa) and respiratory system compliance (1.08 (0.08) vs 0.92 (0.16) ml cm H2O-1 kg-1) and lower PaCO2 (6.5 (0.7) vs 8.7 (1.5) kPa) and shunt fraction (7.2 (2.7)% vs 12.3 (6.2)%) were seen with BVV, with no significant difference in peak airway pressure (16.3 (1.2) vs 15.3 (3.7) cm H2O). A deterioration in gas exchange and respiratory mechanics was seen with conventional control mode ventilation but not with BVV in this experimental model of prolonged anaesthesia.
-
Randomized Controlled Trial Multicenter Study Comparative Study Clinical Trial
Postoperative pain management and recovery after remifentanil-based anaesthesia with isoflurane or propofol for major abdominal surgery. Remifentanil Study Group.
We have assessed if recovery times after morphine or fentanyl, given before terminating remifentanil anaesthesia with isoflurane or propofol, are compromised. We studied patients undergoing elective, major abdominal surgery, allocated randomly to receive remifentanil and isoflurane (n = 277) or remifentanil and propofol (n = 274) anaesthesia. ⋯ Recovery was rapid and at an Aldrete score > or = 9 (median 12-15 min), 42-51% of patients reported none or mild pain. However, 26-35% of patients reported severe pain and > 90% required a second dose of opioid within 21-27 min after anaesthesia.
-
Randomized Controlled Trial Clinical Trial
Differential effects of systemically administered ketamine and lidocaine on dynamic and static hyperalgesia induced by intradermal capsaicin in humans.
We have examined the effect of systemic administration of ketamine and lidocaine on brush-evoked (dynamic) pain and punctate-evoked (static) hyperalgesia induced by capsaicin. In a randomized, double-blind, placebo-controlled, crossover study, we studied 12 volunteers in three experiments. Capsaicin 100 micrograms was injected intradermally on the volar forearm followed by an i.v. infusion of ketamine (bolus 0.1 mg kg-1 over 10 min followed by infusion of 7 micrograms kg-1 min-1), lidocaine 5 mg kg-1 or saline for 50 min. ⋯ Lidocaine reduced the area of punctate-evoked hyperalgesia significantly. It tended to reduce VAS scores of spontaneous pain but had no effect on evoked pain. The differential effects of ketamine and lidocaine on static and dynamic hyperalgesia suggest that the two types of hyperalgesia are mediated by separate mechanisms and have a distinct pharmacology.