British journal of anaesthesia
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Randomized Controlled Trial Comparative Study Clinical Trial
Influence of different colloids on molecular markers of haemostasis and platelet function in patients undergoing major abdominal surgery.
Synthetic colloids have been reported to cause haemorrhagic complications. The effects of perioperative volume replacement with 4% gelatin (n = 20), 6% low-molecular weight (LMW) hydroxyethyl starch (HES) (Mw: 70,000 dalton; HES 70/0.5; n = 20) and 6% medium-molecular weight (MMW) HES (Mw: 200,000 dalton; HES 200/0.5; n = 20) on haemostasis were assessed in patients undergoing major abdominal surgery. Volume was administered to keep central venous pressure (CVP) between 10 and 14 mm Hg. ⋯ Factor VIII and von Willebrand factor (vWF) also increased in all groups beyond the normal range, showing the significantly highest increase in the gelatin-treated group (VIII: from 173 (36) to 266 (33) U dl-1; vWF: from 164(33) to 238 (31) U dl-1). Platelet function remained within the normal range and without group differences throughout the study period. We can conclude that all three solutions can be used safely in patients undergoing major abdominal surgery with regard to the haemostatic process.
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Randomized Controlled Trial Comparative Study Clinical Trial
Nodal rhythm and bradycardia during inhalation induction with sevoflurane in infants: a comparison of incremental and high-concentration techniques.
We studied heart rate and rhythm changes during sevoflurane inhalation induction in 60 healthy, unpremedicated infants. Patients were allocated randomly to receive an incremental (2% sevoflurane, increased every four to six breaths by 2% increments, to 8%) or high-concentration induction technique (8% sevoflurane from the outset). The ECG was recorded for 330 s (30 s pre- and 300 s postinduction) using a mini-Holter device (Recollect Dual Channel, Hertford Medical) and later analysed by an independent observer. ⋯ The onset of nodal rhythm was associated with bradycardia (< 80 bpm) in seven out of 12 cases, and occurred significantly earlier in the high-concentration group (median 123 (range 99-139) s versus 164 (127-138) s). Its duration was similar in both groups (62 (2-84) s versus 90 (20-167) s). These findings highlight the importance of using continuous ECG analysis when studying volatile anaesthetic agents in young children.
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Randomized Controlled Trial Comparative Study Clinical Trial
Intravenous opioids reduce airway irritation during induction of anaesthesia with desflurane in adults.
Desflurane is not used for the induction of anaesthesia despite its favourable pharmacokinetic characteristics because it causes airway irritation. We investigated whether pretreatment with i.v. narcotics reduced unwanted effects. One hundred and eighty adults were randomized to three groups (60 per group) to receive i.v. saline, fentanyl 1 microgram kg-1 and morphine 0.1 mg kg-1, respectively, before inhalational induction with desflurane in nitrous oxide and oxygen. ⋯ Laryngospasm developed in 11.7% of controls compared with 3.3 and 1.7% in the fentanyl and morphine groups, respectively. More patients in the control group had excitatory movements (46.7%) than in the fentanyl (16.7%) and morphine (8.3%) groups. These results demonstrate that i.v. opioids reduce airway irritability significantly during inhalational induction with desflurane in adults.
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Clinical Trial
Pharmacokinetics and clinical efficacy of long-term epidural ropivacaine infusion in children.
The clinical efficacy and pharmacokinetics of long-term epidural ropivacaine infusion were investigated in 18 postoperative children aged between 0.3 and 7.3 yr. A lumbar or thoracic epidural catheter was inserted after the anaesthetic induction. Sixty minutes following a bolus dose of ropivacaine 1 mg kg-1, 0.2% ropivacaine was infused at a fixed rate of 0.4 mg kg-1 h-1 for a mean of 61.3 h (range 36-96 h). ⋯ No clinical signs of local anaesthetic toxicity were seen. Total (100-3189 micrograms litre-1) and free (10-56 micrograms litre-1) ropivacaine concentrations were within the range reported to be 'safe' in previous studies in adults. Mean (95% CI) volume of distribution was 3.1 litre kg-1 (2.1-4.2 litre kg-1), total clearance was 8.5 ml kg-1 min-1 (5.8-11.1 ml kg-1 min-1), free clearance was 220 ml kg-1 min-1 (170-270 ml kg-1 min-1) and elimination half-life was 4.9 h (3.0-6.7 h).
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Comparative Study
Is obstructive sleep apnoea a rapid eye movement-predominant phenomenon?
Obstructive sleep apnoea (OSA) is thought to be worse during rapid eye movement (REM) sleep. REM rebound in the late postoperative period can follow the REM suppression shown to occur after some types of surgery. This is thought to worsen nocturnal episodic hypoxaemia, leading to greater cardio-respiratory risk. ⋯ While a small number clearly desaturate much more during REM, the majority do not. Thus, postoperative REM rebound may worsen OSA in some patients, but in many it may do otherwise. The implications of postoperative sleep disturbance are therefore likely to be more complex than previously suggested.