Hughlings Jackson's early education.
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to M Andrew.
Explore the source record for details and available documents.
BACKGROUND: Maternal hypotension, the most frequent complication of spinal anaesthesia for caesarean section, can be associated with severe nausea or vomiting which can pose serious risks to the mother (unconsciousness, pulmonary aspiration) and baby (hypoxia, acidosis and neurological injury). OBJECTIVES: To assess the effects of prophylactic interventions for hypotension following spinal anaesthesia for caesarean section. SEARCH STRATEGY: We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (November 2005). SELECTION CRITERIA: Randomised controlled trials comparing interventions to prevent hypotension with placebo or alternative treatment in women having spinal anaesthesia for caesarean section. DATA COLLECTION AND ANALYSIS: Three review authors independently assessed eligibility and methodological quality of studies, and extracted data. MAIN RESULTS: We included 75 trials (a total of 4624 women). Crystalloids were more effective than no fluids (relative risk (RR) 0.78, 95% confidence interval (CI) 0.60 to 1.00; one trial, 140 women, sequential analysis) and colloids were more effective than crystalloids (RR 0.68, 95% CI 0.52 to 0.89; 11 trials, 698 women) in preventing hypotension following spinal anaesthesia at caesarean section. No differences were detected for different doses, rates or methods of administering colloids or crystalloids. Ephedrine was significantly more effective than control (RR 0.51, 95% CI 0.33 to 0.78; seven trials, 470 women) or crystalloid (RR 0.70, 95% CI 0.50 to 0.96; four trials, 293 women) in preventing hypotension. No significant differences in hypotension were seen between ephedrine and phenylephrine (RR 0.95, 95% CI 0.37 to 2.44; three trials, 97 women) and phenylephrine was more effective than controls (RR 0.27, 95% CI 0.16 to 0.45; two trials, 110 women). High rates or doses of ephedrine may increase hypertension and tachycardia incidence. Lower limb compression was more effective than control (no leg compression) (RR 0.69, 95% CI 0.53 to 0.90; seven trials, 399 women) in preventing hypotension, although different methods of compression appeared to vary in their effectiveness. No other comparisons between different physical methods such as position were shown to be effective, but these trials were often small and thus underpowered to detect true effects should they exist. AUTHORS' CONCLUSIONS: While interventions such as colloids, ephedrine, phenylephrine or lower leg compression can reduce the incidence of hypotension, none have been shown to eliminate the need to treat maternal hypotension during spinal anaesthesia for caesarean section. No conclusions can be drawn regarding rare adverse effects due to the relatively small numbers of women studied.
BACKGROUND: Psychological interventions are widely used in the treatment of post-traumatic stress disorder (PTSD). OBJECTIVES: To perform a systematic review of randomised controlled trials of all psychological treatments except eye movement desensitisation and reprocessing following the guidelines of the Cochrane Collaboration. SEARCH STRATEGY: Systematic searches of computerised databases, hand search of the Journal of Traumatic Stress, searches of reference lists, known websites and discussion fora, and personal communication with key workers. SELECTION CRITERIA: Types of studies - Any randomised controlled trial of a psychological treatment. Types of participants - Adults suffering from traumatic stress symptoms for three months or more. Types of interventions - Trauma-focused cognitive behavioural therapy/exposure therapy (TFCBT); stress management (SM); other therapies (supportive therapy, non-directive counselling, psychodynamic therapy and hypnotherapy); group cognitive behavioural therapy (group CBT). Types of outcomes - Severity of clinician rated traumatic stress symptoms. Secondary measures included self-reported traumatic stress symptoms, depressive symptoms, anxiety symptoms, adverse effects and dropouts. DATA COLLECTION AND ANALYSIS: Data was entered using the Review Management software. Quality assessments were performed. The data were analysed for summary effects using the RevMan 4.2 programme. MAIN RESULTS: Twenty-nine studies were included in the review. With regards to reduction of clinician assessed PTSD symptoms TFCBT did significantly better than waitlist/usual care (standardised mean difference (SMD) = -1.36; 95% CI, -1.88 to -0.84; 13 studies; n = 609). There was no significant difference between TFCBT and SM (SMD = -0.27; 95% CI, -0.71 to 0.16; 6 studies; n = 239). TFCBT did significantly better than other therapies (SMD = -0.81; 95% CI, -1.19 to -0.42; 3 studies; n = 120). Stress management did significantly better than waitlist/usual care (SMD = -1.14; 95% CI, -1.62 to -0.67; 3 studies; n = 86) and than other therapies (SMD = -1.22; 95% CI, -2.09 to -0.35; 1 study; n = 25). There was no significant difference between other therapies and waitlist/usual care control (SMD = -0.43; 95% CI, -0.90 to 0.04; 2 studies; n = 72). Group TFCBT was significantly better than waitlist/usual care (SMD = -0.72; 95% CI, -1.14 to -0.31). AUTHORS' CONCLUSIONS: There was evidence that individual TFCBT, stress management and group TFCBT are effective in the treatment of PTSD. Other non-trauma focused psychological treatments did not reduce PTSD symptoms as significantly. There was some evidence that individual TFCBT is superior to stress management in the treatment of PTSD at between 2 and 5 months following treatment, and also that TFCBT was also more effective than other therapies. There was insufficient evidence to determine whether psychological treatment is harmful. There was some evidence of greater drop-out in active treatment groups.
Covalent antithrombin-heparin complex (ATH) was covalently grafted to a polycarbonate urethane (Corethane) endoluminal graft (a kind gift of Corvita Corporation) after being activated using 0.3% m/m NaOCl in 0.15 M phosphate pH 6.0. ATH graft density (1.98 x 10(-7) mol/m2) was 6 times the maximum amount of unfractionated heparin (UFH) that could be bound to polycarbonate urethane surfaces. Surface-bound ATH could be stored in sterile 0.15 M NaCl at 4 degrees C for at least 2 months with good antithrombotic activity before being implanted into rabbits. Analysis of ATH-coated tubing showed that it contained significant direct thrombin inhibitory activity. In vivo testing in a rabbit model was compared to non-activated non-coated surfaces, activated-non-coated surfaces, hirudin-coated surfaces and antithrombin (AT)-coated surfaces. The weight of the clot generated in the ATH-coated graft tubing was significantly less than the weight of the clot generated within the hirudin-coated graft (p = 0.03 with a 1-tailed Student's t test). The anticoagulant nature of ATH grafts in vivo was shown to be due to bound ATH because boththe AT-coated surfaces and non-coated but activated surfaces showed similar thromboresistant efficacy to that of untreated material (ANOVA; p < 0.05). Apart from the direct antithrombin activity that contributed to much of the prolonged patency in vivo, surface-bound ATH likely catalyzed AT inhibition of thrombin, as evidenced by a significant number of 125I-AT binding sites (> or = 1.5 x 10(-8) mol/m2). Thus, ATH appears to be a good candidate for coating cardiovascular devices, such as endoluminal grafts, with high levels of substitution and significant long-term blood-compatibility.
This prospective randomized controlled double-blind trial was performed to investigate whether glyceryl trinitrate (GTN) ointment, applied ten minutes after the removal of a eutectic mixture of local anaesthetic cream, lignocaine/ prilocaine (EMLA), influences site selection for intravenous cannulation in children. Eighty children aged between five and 15 years, having general surgery as day patients, received EMLA cream on both hands for 90 minutes prior to transfer to the theatre suite. Acting as their own controls, the children received GTN on one hand, and placebo on the other, after removal of the EMLA cream and ten minutes prior to the insertion of an intravenous cannula. The application of GTN or placebo to left or right hand was blinded and randomized. At induction, the hand with the visually best quality veins was selected and cannulated. The primary outcome was selection between the EMLA/GTN hand and EMLA/placebo hand. The selection having been made, the number of attempts at cannulation, ease of insertion and pain scores (VAS) for cannulation were also recorded. The choice of hand was positively influenced by the use of GTN, with the GTN hand chosen in 51 of 72 (70%) children who completed the protocol (P = 0.001). The findings of this study suggest that the application of GTN after EMLA removal may be clinically useful in aiding cannulation in children.
Explore the source record for details and available documents.
BACKGROUND: Cerebral sinovenous thrombosis in children is a serious disorder, and information is needed about its prevention and treatment. METHODS: The Canadian Pediatric Ischemic Stroke Registry was initiated in 1992 at the 16 pediatric tertiary care centers in Canada. Children (newborn to 18 years of age) with symptoms and radiographic confirmation of sinovenous thrombosis were included. RESULTS: During the first six years of the registry, 160 consecutive children with sinovenous thrombosis were enrolled, and the incidence of the disorder was 0.67 cases per 100,000 children per year. Neonates were most commonly affected. Fifty-eight percent of the children had seizures, 76 percent had diffuse neurologic signs, and 42 percent had focal neurologic signs. Risk factors included head and neck disorders (in 29 percent), acute systemic illnesses (in 54 percent), chronic systemic diseases (in 36 percent), and prothrombotic states (in 41 percent). Venous infarcts occurred in 41 percent of the children. Fifty-three percent of the children received antithrombotic agents. Neurologic deficits were present in 38 percent of the children, and 8 percent died; half the deaths were due to sinovenous thrombosis. Predictors of adverse neurologic outcomes were seizures at presentation and venous infarcts. CONCLUSIONS: Sinovenous thrombosis in children affects primarily neonates and results in neurologic impairment or death in approximately half the cases. The occurrence of venous infarcts or seizures portends a poor outcome.
BACKGROUND: Maternal hypotension is the most frequent complication of a spinal anaesthetic for caesarean section with an incidence approaching 100%. Most workers define hypotension as a maternal systolic blood pressure below 70-80% of baseline recordings and/or an absolute value of < 90 -100mmHg. The frequent occurrence and rapid onset of hypotension during spinal anaesthesia has encouraged anaesthetists to try and prevent or minimise the associated maternal symptoms of nausea and vomiting during the establishment of the block. Untreated, severe hypotension can also pose serious risks to both mother (unconsciousness, pulmonary aspiration, apnoea or even cardiac arrest) and baby (impaired placental perfusion leading to hypoxia, fetal acidosis and neurological injury). A range of strategies is currently used to prevent or minimise hypotension but there is no established ideal technique. OBJECTIVES: To assess the relative efficacy and side effects of prophylactic interventions for hypotension following spinal anaesthesia for caesarean section. SEARCH STRATEGY: The Cochrane Pregnancy and Childbirth Group Trials Register, the Cochrane Controlled Trials Register, other databases and bibliographies of relevant papers are searched according to the strategy developed for the Pregnancy and Childbirth Group as a whole. Date of last search: May 2001. SELECTION CRITERIA: All published or unpublished randomised controlled trials that compare use of an intervention to prevent hypotension with placebo or alternative treatment in patients having spinal anaesthesia for caesarean section. DATA COLLECTION AND ANALYSIS: Trials identified from searching are assessed for inclusion by the same two reviewers independently. Studies are excluded from review for the following reasons: hypotension is not an outcome measure or clearly defined prior to administering a rescue treatment; randomisation is unsatisfactory; the spinal anaesthetic technique or dose of local anaesthetic is not controlled-for; and the intervention is implemented in response to a fall in blood pressure rather than for prevention. Statistical analyses use the Review Manager software for calculation of the treatment effect as represented by the relative risks and proportional and absolute risk reductions. MAIN RESULTS: Twenty trials meet the criteria for inclusion. Four of the twelve interventions reviewed are shown to reduce the incidence of hypotension under spinal anaesthesia for caesarean section: (1) crystalloid 20ml/kg vs control, Relative Risk (RR) 0.78 (95% confidence interval (CI) 0.6, 1.0); (2) pre-emptive colloid administration vs crystalloid, (RR) 0.54 (95% CI 0.37, 0.78); (3) ephedrine vs control, RR 0.70 (95% CI 0.57, 0.85); and (4) lower limb compression vs control, RR 0.75 (95% CI 0.59, 0.94). There are no significant differences in maternal or neonatal side effects in any of the comparisons studied. REVIEWER'S CONCLUSIONS: No studied intervention has been shown to eliminate the need to treat maternal hypotension during spinal anaesthesia for caesarean section. We are unable to draw any conclusions regarding adverse effects of the studied interventions, due to their probable low incidence and the small number of women studied. Further randomised controlled trials are recommended, in particular assessing a combination of the beneficial interventions, i.e. colloid or crystalloid preloading, parenteral ephedrine administration and leg compression with bandages, stockings or inflatable boots.
OBJECTIVE: Patients with cystic fibrosis (CF) and pancreatic insufficiency (PI) commonly have vitamin K deficiency, and those with CF-associated liver disease (CFLD) have universal vitamin K deficiency. We evaluated the effectiveness of an oral fat-soluble vitamin combination (ADEKs) to treat patients with vitamin K deficiency. STUDY DESIGN: Patients with PI and CF (mean age, 15 years; range, 0.6 to 46 years) including 6 with advanced CFLD were prospectively enrolled in a study of a fat-soluble vitamin combination taken on a daily basis. None had received vitamin K supplementation for at least 4 months before the study. Fat-soluble vitamin combination supplementation was given for a minimum of 4 months; the mean vitamin K intake was 0.18 mg/d (SD = 0.1, range, 0 to 0.3). The primary outcome was change in plasma PIVKA-II (prothrombin in vitamin K absence). RESULTS: Before supplementation 58 (81%) of 72 patients had abnormal PIVKA-II levels (>2.9 ng/mL). After supplementation 29 (40%) had abnormal PIVKA-II levels (P =.001). All 6 patients with advanced CFLD had abnormal PIVKA-II levels (median, range of 20.8, 5.5 to 55 ng/mL) before treatment, which corrected to normal in 50% (4.1, 2.1 to 65 ng/mL). Four patients, 2 with CFLD, had a prolonged prothrombin time (>13.5 seconds) at both time periods. CONCLUSIONS: An oral fat-soluble vitamin combination with a modest amount of vitamin K can, as a daily supplement, improve the PIVKA-II levels in patients with PI and CF.
We evaluated the efficacy and safety of alteplase to restore central venous line (CVL) patency in a consecutive cohort study. A uniform, weight-dependent protocol for alteplase administration was established prospectively. For children < or =10 kg, a dose of 0.5 mg was used; for children >10 kg, doses of 1 to 2 mg were used. The alteplase remained instilled for 1 to 4 hours or overnight. Retrospective data accrual found that 25 children received alteplase for a total of 34 courses; 29 (85%) of the 34 courses of alteplase completely restored CVL patency. Alteplase appears to be a safe and effective thrombolytic agent for CVL patency restoration in children.
OBJECTIVES: In this study, we tried to determine the safety and outcomes of thrombolysis with tissue plasminogen activator of intravascular thrombus. STUDY DESIGN: Eighty consecutive children were treated between 1985 and 1999 in a tertiary care setting in a retrospective case series. There were 65 arterial thrombi (56 after cardiac catheterization) and 15 venous thrombi treated with tPA at an average dose of tPA of 0.5 mg/kg/hour for a median duration of 6 hours. RESULTS: Clot resolution was complete in 65% of children, partial in 20%, and there was no effect in 15%. There were major complications in 40%, minor complications in 30%, and no complications in 30%. Two patients had cerebral ischemia secondary to hypotension because of profound bleeding, with intracranial hemorrhage in 2 additional patients. Clot resolution was not related to patient age or weight, dose, and duration of tPA therapy and fibrinogen levels. However, complications were more likely in patients who weighed less, had a longer duration of therapy, a greater decrease in fibrinogen levels, and who failed to have resolution of their clot. CONCLUSIONS: tPA therapy can be effective in the thrombolysis of intravascular thrombus in children, but is associated with a low margin of safety and an unknown risk-benefit ratio.
BACKGROUND: Prescribing feedback based on aggregated data alone does not give the information needed to improve treatment quality. OBJECTIVES: Our aim was to develop a new method, or tool, of presenting prescribing feedback which, combined with guideline recommendations, makes it possible for doctors to judge their own prescribing as good or bad. METHODS: Asthma was chosen as a disease model, as treatment recommendations are readily available published as national and international guidelines. Four mean daily dosage intervals of inhaled short-acting beta-agonists and four mean daily dosage intervals of inhaled steroids were combined into a 4 x 4 matrix. This matrix of 16 combined dosage boxes was presented to 68 Norwegian GPs participating in peer review groups. As a first step, the GPs in the groups reached consensus on what they considered to be appropriate and inappropriate combined dosage intervals of these drugs based on national guideline recommendations and their joint clinical experience. Accordingly, traffic-light colours, green and red, were assigned to the combined dosage boxes in the matrix. Treatments in boxes difficult to judge were coloured yellow. During a 1-year period prior to the consensus meetings, the dispensed inhaled short-acting beta-agonists and inhaled steroids of each of the doctors' patients were recorded at the local pharmacies. As a second step in developing the new method, the number of patients treated within each of the coloured boxes was presented to the GPs in the peer review groups. These combined presentations provided an overview to the whole group, and individually to each GP, of how many patients were actually given appropriate or inappropriate treatment according to their own agreed upon standard. RESULTS: The GPs categorized 34% of 1122 evaluated patients receiving inhaled short-acting beta-agonists or inhaled steroids as treated inappropriately during the 1-year registration period. Appropriate treatment was given to 47% of the patients, and in 19% of the cases the treatment was difficult to evaluate. CONCLUSIONS: A method has been developed enabling GPs to categorize prescribing information into good (green), bad (red) and difficult to judge (yellow) treatment qualities, based on guideline recommendations and clinical experience. The actual prescribing data for each GP were labelled according to the same colour scheme, thus revealing to each GP his or her own actual prescribing compared with their own treatment standard, yielding information and motivation for quality improvement efforts.
The potential role of therapeutic ultrasound in medicine is promising. Currently, medical devices are being developed that utilize high-intensity focused ultrasound as a noninvasive method to treat tumors and to stop bleeding (hemostasis). The primary advantage of ultrasound that lends the technique so readily to use in noninvasive therapy is its ability to penetrate deep into the body and deliver to a specific site thermal or mechanical energy with submillimeter accuracy. Realizing the full potential of acoustic therapy, however, requires precise targeting and monitoring. Fortunately, several imaging modalities can be utilized for this purpose, thus leading to the concept of image-guided acoustic therapy. This article presents a review of high-intensity focused ultrasound therapy, including its mechanisms of action, the imaging modalities used for guidance and monitoring, some current applications, and the requirements and technology associated with this exciting and promising field.
BACKGROUND AND PURPOSE: The purpose of this study was to determine whether infection with varicella is causal for arterial ischemic stroke (AIS) in children. METHODS: First, a prospective cohort study was conducted in young children (aged 6 months to 10 years) with AIS at 2 institutions (cohort study). The presence of varicella infection <12 months before AIS was determined and compared with the published frequency of varicella infection in the healthy pediatric population. The clinical and radiographic features of AIS were compared between the varicella and nonvaricella study cohorts. Second, a literature search of varicella-associated AIS was conducted, and the clinical and radiographic features were compared with the study nonvaricella cohort. RESULTS: In the cohort study, 22 (31%) of 70 consecutive children with AIS had a varicella infection in the preceding year compared with 9% in the healthy population. Children in the varicella cohort were more likely to have basal ganglia infarcts (P<0.001), abnormal cerebral vascular imaging (P<0.05), and recurrent AIS or transient ischemic attacks (P<0.05) than those in the nonvaricella cohort. The pooled literature analysis of 51 cases of varicella-associated AIS showed similar findings to the varicella cohort. CONCLUSION: In young children with AIS, there is a 3-fold increase in preceding varicella infection compared with published population rates, and varicella-associated AIS accounts for nearly one third of childhood AIS. Varicella-associated AIS has characteristic features, including a 2-fold increase in recurrent AIS and transient ischemic attacks. Varicella is an important risk factor for childhood AIS.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
We assessed whether frozen recombinant tissue plasminogen activator (rt-PA) remains stable and sterile for up to 22 weeks at -30 degrees C. Our findings confirm that rt-PA is a cost-effective alternative to urokinase for restoring patency to occluded central venous catheters.
OBJECTIVE: Low molecular weight heparins (LMWHs) offer several advantages over standard anticoagulant therapy (unfractionated heparin/warfarin) including predictable pharmacokinetics, minimal monitoring, and subcutaneous administration. Our objective was to determine the safety and efficacy of LMWHs in children. METHODS: A prospective cohort of children treated with the LMWH enoxaparin (Rhone Poulenc Rorer) was monitored at the Hospital for Sick Children, Toronto, Canada, from March 1994 until July 1997. RESULTS: There were 146 courses of LMWH administered for treatment and 31 courses for prophylaxis of thromboembolic events (TEs). Clinical resolution of TEs occurred in 94% of children receiving therapeutic doses of LMWH, and 96% of children receiving prophylactic doses of LMWH had no symptoms of recurrent or new TEs. Major bleeding occurred in 5% of children receiving therapeutic doses. Recurrent or new TEs occurred in 1% and 3% of children receiving therapeutic and prophylactic doses of LMWH, respectively. CONCLUSION: LMWH appears to be efficacious and safe for both management and prophylaxis of TEs. The results of this cohort study justify a randomized controlled trial comparing LMWH with standard therapy for the management of TEs in children.