Search PubMed⌕ Search

Biomedical subjects

C Bladin

Publications and source records attributed to C Bladin.

12 recordsLinked to original sources

Thrombolytic therapy for acute ischaemic stroke: successful implementation in an Australian tertiary hospital.

The use of tissue-type plasminogen activator (t-PA) in ischaemic stroke outside of experienced stroke centres remains controversial. The aim of this study was to present the initial experience with t-PA in patients with ischaemic stroke at an institution with no prior experience in i.v. stroke thrombolysis and to compare results to published reports. Prospective audit of 888 patients with consecutive stroke and transient ischaemic attack admitted to a 426-bed tertiary referral hospital from March 2003 to October 2005. Main outcome measures were treatment rate, exclusion criteria, protocol violations, intracerebral haemorrhage, disability (modified Rankin scale) and mortality at 3 months. Over the study period, 72 patients received t-PA (11% of ischaemic strokes). The main reason for exclusion was presentation beyond 3 h of onset (44%); if all eligible patients had arrived within 3 h, treatment rate was estimated at 32.5%. Protocol violations occurred in 15 (21%) patients. There were seven (10%) asymptomatic intracerebral haemorrhage and one (1%) non-fatal symptomatic intracerebral haemorrhage. At 3 months, 37% had achieved excellent recovery (modified Rankin scale 0-1) and seven (10%) had died. The delivery and outcomes associated with the use of t-PA were comparable to the results of the National Institute of Neurological Disorders and Stroke trial and meta-analysis of open-labelled studies. With appropriate infrastructure and protocols, previously inexperienced tertiary referral centres can replicate the experience and outcome measures reported by clinical trials of t-PA in patients with stroke.

Aged↗

Refining the perfusion-diffusion mismatch hypothesis.

BACKGROUND AND PURPOSE: The Echoplanar Imaging Thrombolysis Evaluation Trial (EPITHET) tests the hypothesis that perfusion-weighted imaging (PWI)-diffusion-weighted imaging (DWI) mismatch predicts the response to thrombolysis. There is no accepted standardized definition of PWI-DWI mismatch. We compared common mismatch definitions in the initial 40 EPITHET patients. METHODS: Raw perfusion images were used to generate maps of time to peak (TTP), mean transit time (MTT), time to peak of the impulse response (Tmax) and first moment transit time (FMT). DWI, apparent diffusion coefficient (ADC), and PWI volumes were measured with planimetric and thresholding techniques. Correlations between mismatch volume (PWIvol-DWIvol) and DWI expansion (T2(Day 90-vol)-DWI(Acute-vol)) were also assessed. RESULTS: Mean age was 68+/-11, time to MRI 4.5+/-0.7 hours, and median National Institutes of Health Stroke Scale (NIHSS) score 11 (range 4 to 23). Tmax and MTT hypoperfusion volumes were significantly lower than those calculated with TTP and FMT maps (P<0.001). Mismatch > or =20% was observed in 89% (Tmax) to 92% (TTP/FMT/MTT) of patients. Application of a +4s (relative to the contralateral hemisphere) PWI threshold reduced the frequency of positive mismatch volumes (TTP 73%/FMT 68%/Tmax 54%/MTT 43%). Mismatch was not significantly different when assessed with ADC maps. Mismatch volume, calculated with all parameters and thresholds, was not significantly correlated with DWI expansion. In contrast, reperfusion was correlated inversely with infarct growth (R=-0.51; P=0.009). CONCLUSIONS: Deconvolution and application of PWI thresholds provide more conservative estimates of tissue at risk and decrease the frequency of mismatch accordingly. The precise definition may not be critical; however, because reperfusion alters tissue fate irrespective of mismatch.

Aged↗

Intercenter agreement in reading Doppler embolic signals. A multicenter international study.

BACKGROUND AND PURPOSE: Different frequencies of asymptomatic Doppler embolic signals have been reported in studies. There has been concern that different criteria for identification may account for some of this variation. A previous reproducibility study between two centers found good agreement, but no studies among large numbers of centers have been performed. We performed an international reproducibility study among nine centers, each of which had published recent studies of embolic signal detection in peer-reviewed journals. METHODS: Each center performed blinded analysis of a taped audio Doppler signal composed of transcranial Doppler middle cerebral artery recordings from 6 patients with symptomatic carotid artery stenosis. The exact time of any embolic signal was recorded. Six centers also measured the intensity increase of any embolic signals detected. Interobserver agreement was determined by a method based on the proportion of specific agreement. RESULTS: Seven centers reported between 39 and 55 signals, but one center reported 142 embolic signals. The probability of agreement between observers was .678, which rose to .791 when the data from the highest reporting center were excluded. Introducing a decibel threshold resulted in a significant increase in the probability of agreement; a decibel threshold of > 7 dB resulted in a probability of agreement of .902. Intensity measurements made by different centers were usually highly correlated, but this was not always the case, and 3 of the 15 correlations were not significant. The absolute values of the intensities measured varied between centers by as much as 40%. CONCLUSIONS: Although most centers report similar numbers of embolic signals, some use less specific criteria and report more events. The use of a decibel threshold improves reproducibility. However, intensity thresholds developed by one center cannot be directly transferred without validation to another center; differing methods of measurement are being used, and this results in different intensity values for the same embolic signals, even when the same equipment is used.

Carotid Stenosis↗

Fractures of the lateral process of the talus: a clinical review. "Snowboarder's ankle".

OBJECTIVE: This is a review article discussing the incidence, aetiology, investigation, and management of fractures of the lateral process of the talus, an uncommon but increasingly recognised complication of snowboarding. DATA SOURCES: The data regarding aetiology, investigation, and management of these fractures were obtained through a comprehensive literature review utilising the Medline, Sport discus, Medline Orthopaedic, and Cinahl databases. Injury data were obtained through published prospective epidemiological studies of snowboarding injuries. STUDY SELECTION: All studies of talar fractures, particularly of the lateral process, were included in the review. All prospective and retrospective studies of snowboarding injuries were reviewed. DATA SYNTHESIS: The mechanism of this injury appears to be a combination of dorsiflexion and inversion of the ankle. The combination of soft-shell snowboarding boots and aerial maneuvers increase the likelihood of injury. Clinically these injuries resemble severe ligamentous ankle sprains and are commonly misdiagnosed. The fractures can be classified into three subtypes based on the severity of the bony injury. The management of each injury subtype differs and although no prospective treatment trials have been performed the published risk of long term degenerative subtalar joint damage warrant aggressive early management of this injury. CONCLUSIONS: With the increasing popularity of snowboarding, the possibility of this injury should be considered in all ankle injuries related to this sport. Once diagnosed, management guidelines should be followed in order to minimise long term problems.

Ankle Injuries↗

Snowboarding injuries. An overview.

Over the last 10 years, snowboarding has become established as a popular and legitimate alpine sport. However, at present, there are few epidemiological studies examining the spectrum of injuries associated with this new sport. Snowboarders are typically male (male: female ratio of 3:1) and in their early twenties. They have an injury rate of 4 to 6 per 1000 visits, which is comparable to that which occurs with skiing. However, in contrast to skiing, in which only 34% of those injured are beginners, the majority (60%) of snowboarders injured are beginners. This is a reflection of the participant profile of this developing sport. 57% of injuries occur in the lower limbs, and 30% in the upper limbs. The most common injuries are simple sprains (31 to 53%), particularly of the ankles (23 to 26%) and knees (12 to 23%), followed by fractures (24 to 27%) and contusions (12%). Compared with skiing injuries, snowboarders have 2.4 times as many fractures, particularly of the upper limbs (constituting 21 vs 35% of upper limb injuries), fewer knee injuries (23 vs 44% of lower limb injuries), but more ankle injuries (23 vs 6% of lower limb injuries). Snowboarding knee injuries are less severe than those associated with skiing. Fracture of the lateral process of the talus is an unusual and uncommon snowboarding injury that can be misdiagnosed as a severe ankle sprain. Ankle injuries are more common with soft shell boots, whereas knee injuries and distal tibia fractures are more common with hard shell boots.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Australian snowboard injury data base study. A four-year prospective study.

Information on the rate and spectrum of snowboarding injuries is limited. This 4-year prospective study at 3 major Australian ski resorts assesses incidence and patterns of snowboarding injuries, particularly in relation to skill level and footwear. Ski injury data were collected for the same period. In a predominantly male study population (men:women, 3:1), 276 snowboarding injuries were reported; 58% occurred in novices. Fifty-seven percent of injuries were in the lower limbs, 30% in the upper limbs. The most common injuries were sprains (53%), fractures (24%), and contusions (12%). Comparing skiers' versus snowboarders' injuries, snowboarders had 2.4 times as many fractures, particularly to the upper limbs (21% versus 35% of upper limb injuries), fewer knee injuries (23% versus 44% of lower limb injuries), but more ankle injuries (23% versus 6% of lower limb injuries). Ankle injuries were more common with soft-shell boots, worn most by intermediate and advanced riders. Knee injuries and distal tibial fractures were more common with hard-shell boots, worn most by novices. Overall, novices had more upper limb fractures and knee injuries; intermediate and advanced riders had more ankle injuries. Falls were the principal mode of injury. To prevent injury, beginners should use "hybrid" or soft-shell boots and take lessons.

Adolescent↗