Abstract:
BACKGROUND:Studies of the accuracy of partial rebreathing measurements of pulmonary blood flow (PBF) in patients with abnormal lungs have not fully explained the sources of error. METHODS:We used computer models of emphysema and pulmonary embolism incorporating both ventilation-perfusion (V/Q) and ventilation-volume (V/V) heterogeneity to investigate systematic errors in partial rebreathing PBF measurements. We studied (i) errors produced under usual conditions, (ii) effects of recirculation, (iii) effects of alveolar-proximal airway and alveolar-capillary PCO2 and VCO2 differences, (iv) effects of alveolar V/Q inhomogeneity and (v) effects of rebreathing time. RESULTS:In the pulmonary embolism model the systematic error is only acceptable (<10%) when the simulated PBF is low (2-3 litre min(-1)). In the emphysema model PBF is underestimated by more than 20% at all cardiac outputs studied. Four sources of systematic errors were found. (i) Alveolar-proximal airway PCO2 gradients and flux differences between the proximal airway and alveolar compartments contribute most to the systematic error. (ii) V/Q inhomogeneity causes PCO2 gradients between the alveolar compartments and pulmonary capillary blood, and between pulmonary capillary compartments. (iii) Rebreathing times are inadequate in the presence of V/V mismatch. (iv) The apparent effect of venous blood recirculation is small in emphysema but significant in pulmonary embolism. CONCLUSIONS:We conclude that PBF cannot be measured accurately by partial rebreathing in lungs with emphysema or embolism. Systematic errors are caused mainly by errors in end-tidal PCO2 values.
journal_name
Br J Anaesthjournal_title
British journal of anaesthesiaauthors
Yem JS,Turner MJ,Baker ABdoi
10.1093/bja/ael214subject
Has Abstractpub_date
2006-11-01 00:00:00pages
732-41issue
5eissn
0007-0912issn
1471-6771pii
S0007-0912(17)35379-5journal_volume
97pub_type
杂志文章abstract:BACKGROUND:Guidelines recommend discontinuation of clopidogrel for 7 days before a neuraxial injection, while other directives suggest that 5 days might be adequate. We examined the time course of antiplatelet activity after clopidogrel discontinuation in patients undergoing epidural injections. METHODS:Thirteen patie...
journal_title:British journal of anaesthesia
pub_type: 杂志文章
doi:10.1093/bja/aer298
更新日期:2011-12-01 00:00:00
abstract:BACKGROUND:Microalbuminuria, often referred to as the urinary albumin-creatinine ratio (ACR), is thought to be a reflection of increased capillary permeability associated with the systemic inflammatory response syndrome, and has been found to be predictive of outcome in several studies. Therefore, we explored the usefu...
journal_title:British journal of anaesthesia
pub_type: 杂志文章
doi:10.1093/bja/ael211
更新日期:2006-10-01 00:00:00
abstract:BACKGROUND:Risks and costs of allogeneic blood transfusions mandate strategies to reduce blood loss in surgery. The objective of this study was to assess the efficacy of antifibrinolytic treatment in reducing perioperative blood loss during total knee replacement. METHODS:A double-blind, randomized and placebo-control...
journal_title:British journal of anaesthesia
pub_type: 杂志文章,随机对照试验
doi:10.1093/bja/ael057
更新日期:2006-05-01 00:00:00
abstract:BACKGROUND:The optimal dose of oxytocin at Caesarean section is unclear. Oxytocin may cause adverse cardiovascular effects, including tachycardia and hypotension, whereas an inadequate dose can result in increased uterine bleeding. We compared the effects of two doses of oxytocin in a randomized double-blind trial. ME...
journal_title:British journal of anaesthesia
pub_type: 杂志文章,随机对照试验
doi:10.1093/bja/aen273
更新日期:2008-12-01 00:00:00
abstract::We have investigated the effect of a bolus injection of atracurium 0.6 mg kg-1 on the cardiovascular system in 16 patients undergoing aortocoronary bypass surgery. H1- and H2-receptor antagonists were administered to eight patients before the neuromuscular blocker. A standard anaesthetic was used comprising fentanyl, ...
journal_title:British journal of anaesthesia
pub_type: 临床试验,杂志文章
doi:10.1093/bja/68.2.155
更新日期:1992-02-01 00:00:00
abstract::A genetic disorder of the calcium releasing ryanodine receptor has recently been postulated in malignant hyperthermia (MH) and ryanodine-induced contractures differ between subjects who are malignant hyperthermia susceptible (MHS) and non-susceptible (MHN). We tested 39 patients from 26 families for MH, using the proc...
journal_title:British journal of anaesthesia
pub_type: 杂志文章
doi:10.1093/bja/71.2.242
更新日期:1993-08-01 00:00:00
abstract::Experiments were performed on rats using two analgesimetric tests (tail-flick; hot-plate) before and after injection i.v. of graded doses of aprotinin (12.5, 25.0 and 50 KIU g-1). A dose-related analgesic effect was noted with both tests. Prior administration of naloxone 0.001 mg g-1 i.p. inhibited the analgesic actio...
journal_title:British journal of anaesthesia
pub_type: 杂志文章
doi:10.1093/bja/52.11.1107
更新日期:1980-11-01 00:00:00
abstract:BACKGROUND:The oesophageal leak pressure is defined as the pressure which breaks the seal between the cuff of a supraglottic airway and the peri-cuff mucosa, allowing penetration of fluid into the pharynx and the oral cavity. As a consequence, a decrease in this variable increases the risk of reflux and can lead to pul...
journal_title:British journal of anaesthesia
pub_type: 杂志文章
doi:10.1093/bja/aev435
更新日期:2016-02-01 00:00:00
abstract::We have investigated the value of lower oesophageal contractility (LOC) in detecting awareness during anaesthesia in 20 human volunteer patients. LOC was measured either with subjects awake or after induction with propofol, during induction with propofol, and then as consciousness returned. Statistically significant c...
journal_title:British journal of anaesthesia
pub_type: 杂志文章
doi:10.1093/bja/65.3.319
更新日期:1990-09-01 00:00:00
abstract::Intrathecal midazolam causes antinociception by combining with spinal cord benzodiazepine receptors. This effect is reversible with doses of naloxone, suggesting involvement of spinal kappa or delta but not mu opioid receptors. The antinociceptive effects of intrathecally administered drugs in the spinal cord were dem...
journal_title:British journal of anaesthesia
pub_type: 杂志文章
doi:10.1093/bja/77.6.758
更新日期:1996-12-01 00:00:00
abstract::This study has examined the effect of hydration on immediate recovery from anaesthesia in two groups of 15 patients undergoing therapeutic abortion. A standard anaesthetic technique was administered. Patients in group I received no preoperative fluid; those in group II received, before anaesthesia, 20 ml kg-1 of 4% gl...
journal_title:British journal of anaesthesia
pub_type: 临床试验,杂志文章
doi:10.1093/bja/68.6.576
更新日期:1992-06-01 00:00:00
abstract::In a prospective randomized multi-centre study, the mortality following internal fixation surgery for fracture of the upper femur was investigated in 538 elderly patients allocated to receive subarachnoid blockade or general (narcotic-relaxant) anaesthesia. The 28-day mortality was 6.6% with subarachnoid, and 5.9% wit...
journal_title:British journal of anaesthesia
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1093/bja/59.9.1080
更新日期:1987-09-01 00:00:00
abstract::We have investigated whether nitrous oxide antagonizes or augments the CNS stimulant action of laudanosine in mice by comparing the mean convulsive doses (CD50 (SE] of a control group and those following pretreatment with 65% nitrous oxide in oxygen for 20 and 180 min. Nitrous oxide significantly increased CD50 from 4...
journal_title:British journal of anaesthesia
pub_type: 杂志文章
doi:10.1093/bja/65.5.704
更新日期:1990-11-01 00:00:00
abstract::Percutaneous dilatational tracheostomy (PDT) is associated with a number of life-threatening complications. We present a case of massive and fatal arterial haemorrhage that occurred in the intensive care unit during an elective PDT on an 86-year-old woman following earlier evacuation of a traumatic subdural haematoma....
journal_title:British journal of anaesthesia
pub_type: 杂志文章
doi:10.1093/bja/aeg074
更新日期:2003-04-01 00:00:00
abstract::The problems of selection of tracheal tubes, and the need for a rationale, are outlined. Tracheal tubes of 7.5 mm and 8.5 mm i.d. are recommended for female and male patients, respectively. Tracheal size was determined using high pressure-low volume cuffs as measuring devices. The average diameter of the cuff at seal ...
journal_title:British journal of anaesthesia
pub_type: 杂志文章
doi:10.1093/bja/58.1.111
更新日期:1986-01-01 00:00:00
abstract:BACKGROUND:The effect of anaesthetic drugs on long-term oncological outcomes after cancer surgery is an area of current interest. Dexamethasone is widely used in anaesthetic practice; however, its effect on long-term survival and cancer outcomes is not known. This study presents the results of a 5-yr follow-up of patie...
journal_title:British journal of anaesthesia
pub_type: 杂志文章,随机对照试验
doi:10.1093/bja/aet577
更新日期:2014-07-01 00:00:00
abstract::We have studied the complications associated with three techniques used to maintain extradural analgesia in labour: midwife top-up doses of 0.25% bupivacaine 10 ml, continuous infusion of 0.125% bupivacaine 10 ml h-1 and patient-controlled extradural analgesia (PCEA) with self-administered 3-ml bolus doses of 0.25% bu...
journal_title:British journal of anaesthesia
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1093/bja/73.5.619
更新日期:1994-11-01 00:00:00
abstract:BACKGROUND:Recent studies have concluded that i.v. dexamethasone can prolong the duration of peripheral nerve blockade. We hypothesized that a 4 mg dose would equally prolong the duration of psoas compartment blocks (PCBs) when compared with 8 mg, and that both doses would prolong the duration when compared with placeb...
journal_title:British journal of anaesthesia
pub_type: 杂志文章,随机对照试验
doi:10.1016/j.bja.2017.11.073
更新日期:2018-02-01 00:00:00
abstract:BACKGROUND:As 6% hydroxyethyl starch (HES) 130/0.40 or 130/0.42 can originate from different vegetable sources, they might have different clinical effects. The purpose of this prospective, randomized, double-blind controlled trial was to compare two balanced tetrastarch solutions, one maize-derived and one potato-deriv...
journal_title:British journal of anaesthesia
pub_type: 杂志文章,随机对照试验
doi:10.1093/bja/aew249
更新日期:2016-10-01 00:00:00
abstract:BACKGROUND:Growing evidences indicate that inhalational anaesthetics can enhance the growth and malignant potential of tumour cells and may affect tumour recurrence after surgery. Tumour stem cells play a vital role in tumour recurrence. This study investigates the effect of sevoflurane on glioma stem cells (GSCs) in v...
journal_title:British journal of anaesthesia
pub_type: 杂志文章
doi:10.1093/bja/aeu402
更新日期:2015-05-01 00:00:00
abstract:BACKGROUND:Multiple cognitive and psychiatric disorders are associated with an increased tonic inhibitory conductance that is generated by α5 subunit-containing γ-aminobutyric acid type A (α5 GABAA) receptors. Negative allosteric modulators that inhibit α5 GABAA receptors (α5-NAMs) are being developed as treatments for...
journal_title:British journal of anaesthesia
pub_type: 杂志文章
doi:10.1016/j.bja.2020.11.032
更新日期:2020-12-30 00:00:00
abstract:BACKGROUND:Near-infrared spectroscopy non-invasively measures regional cerebral oxygen saturation. Intraoperative cerebral desaturations have been associated with worse neurological outcomes. We investigated whether perioperative cerebral desaturations are associated with postoperative delirium in older patients after ...
journal_title:British journal of anaesthesia
pub_type: 杂志文章
doi:10.1016/j.bja.2019.09.042
更新日期:2020-02-01 00:00:00
abstract::Human plasma cholinesterase (E.C. 3.1.1.8) was shown to be inhibited by physiological concentrations of propanidid and suxamethonium using a colourimetric assay at 25 degrees C and pH 7.2 unit with butyrylthiocholine as substrate. Propanidid inhibited the enzyme in a non-competitive manner (I50 = 2.0 mmol litre-1; app...
journal_title:British journal of anaesthesia
pub_type: 杂志文章
doi:10.1093/bja/51.3.181
更新日期:1979-03-01 00:00:00
abstract::Summary While complex physiological mechanisms exist to regulate and optimize tissue oxygenation under various conditions, clinical and experimental evidence indicates that anaemia, unchecked, is associated with organ injury and unfavourable outcomes. More data (especially from human studies) are needed to answer ques...
journal_title:British journal of anaesthesia
pub_type: 杂志文章,评审
doi:10.1093/bja/aer350
更新日期:2011-12-01 00:00:00
abstract::In a prospective, randomized, double-blind clinical study, we have studied 100 children, aged 2-12 yr, to compare halothane and sevoflurane in outpatient dental anaesthesia. All patients were unpremedicated and received inhalation induction using nitrous oxide in oxygen supplemented with either halothane (maximum insp...
journal_title:British journal of anaesthesia
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1093/bja/79.3.280
更新日期:1997-09-01 00:00:00
abstract::Chinese hamster fibroblast cells in stirred suspension cultures were exposed to volatile anaesthetic agents for 3 hr or for 24 hr. Cell viability was measured as colony forming ability and was found to be reduced, in a dose related manner, by halothane, chloroform, methoxyflurane, trichloroetheylene and diethyl ether....
journal_title:British journal of anaesthesia
pub_type: 杂志文章
doi:10.1093/bja/47.8.831
更新日期:1975-08-01 00:00:00
abstract::Control measurements of blood flow through and cefoxitin extraction ratios across heart and lungs, liver, kidneys and gut were made under steady-state conditions in awake unrestrained sheep. The studies then were repeated with the same animals anaesthetized with 1.5% halothane or whilst undergoing high thoracic (to ap...
journal_title:British journal of anaesthesia
pub_type: 杂志文章
doi:10.1093/bja/57.12.1239
更新日期:1985-12-01 00:00:00
abstract::Pyridostigmine 0.143 mg kg-1 (maximum 10 mg) and atropine 0.0143 mg kg-1 (maximum 1 mg) were administered i.v. to six healthy male volunteers. Peripheral venous blood samples were drawn for measurement of serum cholinesterase activity. Maximum inhibition of the enzyme was found 5 min after injection with a decrease to...
journal_title:British journal of anaesthesia
pub_type: 杂志文章
doi:10.1093/bja/57.2.204
更新日期:1985-02-01 00:00:00
abstract::Infusion thrombophlebitis is a common complication of i.v. infusions. Many factors appear to be involved in its aetiology, of which the duration of infusion, the drugs infused and the solution(s) infused are the most important. Effective prophylaxis should be based on an understanding of the possible pathophysiology. ...
journal_title:British journal of anaesthesia
pub_type: 杂志文章,评审
doi:10.1093/bja/57.2.220
更新日期:1985-02-01 00:00:00
abstract:INTRODUCTION:Current guidelines suggest a fasting time of 2 h for clear fluids, which is often exceeded in clinical practice, leading to discomfort, dehydration and stressful anaesthesia induction to patients, especially in the paediatric population. Shorter fluid fasting might be a strategy to improve patient comfort ...
journal_title:British journal of anaesthesia
pub_type: 杂志文章,随机对照试验
doi:10.1093/bja/aeu399
更新日期:2015-03-01 00:00:00