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Biomedical subjects

T J Edwards

Publications and source records attributed to T J Edwards.

At least 19 recordsLinked to original sources
PubMed2004

Damage control laparotomy.

BACKGROUND: Damage Control Surgery (DCS) is well established in the management of trauma. This study assessed the results of DCS in the management of critically ill patients who had not had trauma. METHODS: This was a prospective series of patients treated by DCS. The Physiological and Operative Severity Score for the enUmeration of Mortality and morbidity (POSSUM) and Portsmouth predictor equation (P-POSSUM) were used to predict the risk of death, which was compared with the observed mortality rate. RESULTS: Fourteen patients were studied. Nine had sepsis from gastrointestinal perforation. Eight of these underwent bowel resection without anastomosis or stoma formation at the initial laparotomy. Six patients later underwent bowel anastomosis and two had an end stoma formed at second laparotomy. A further three patients had a ruptured aortic aneurysm, one had a reactionary haemorrhage after elective aortic surgery, and one had a retroperitoneal bleed; all required haemostatic packing that was removed at second laparotomy. Mortality rates predicted by POSSUM and P-POSSUM scoring were 64.5 and 49.6 per cent respectively. One patient (7.1 per cent) died after operation, giving an observed mortality rate significantly lower than predicted (P = 0.002 and P = 0.038 versus values predicted by POSSUM and P-POSSUM, respectively). CONCLUSION: The use of DCS in the treatment of critically ill patients resulted in a lower mortality rate than that predicted by POSSUM or P-POSSUM. DCS should not be restricted to trauma.

Adult↗
PubMed2004

Improving risk disclosure during the consent process.

OBJECTIVES: To provide guidance about the risks which should be disclosed to patients and documented during the consent process. METHODS: The Delphi Consensus Technique was used to decide what constitutes mandatory risk disclosure for three index procedures. Documentation of risk on consent forms was audited and compared to these locally agreed standards. A four stage strategy for change was undertaken following which practice was reviewed. RESULTS: Mean mandatory risk documentation rose from 61.2% (95% CI: 58.1-64.4) pre-intervention, to 78.1% (95% CI: 72.6-83.6) post-intervention (ccc2; P < 0.001). CONCLUSIONS: Although we demonstrated some benefit from this simple approach, the need for pragmatic means of achieving and sustaining complete discussion and documentation of risks across all surgical interventions based on universally accepted standards remains.

Humans↗
PubMed2001

The relationship between hematocrit and bleeding time in very low birth weight infants during the first week of life.

OBJECTIVES: The bleeding time is a measurement of platelet and capillary interaction following a small standardized cutaneous incision. In adults, anemia causes a prolongation of the bleeding time, and we hypothesized that the same would be true in very low birth weight (VLBW) infants during their first week of life. STUDY DESIGN: Template bleeding times, using the Surgicutt Newborn device, were performed on 20 VLBW weight infants 0.28 l/l had no significant reduction in bleeding time following transfusion. CONCLUSIONS: In VLBW infants, during their first week of life (the time when their risk of intraventricular hemorrhage is greatest), a low hematocrit is associated with a significant prolongation in the bleeding time.

Bleeding Time↗
PubMed1998

Functional hemodynamic assessment of the 21-mm and 23-mm CarboMedics Top Hat aortic prosthetic valve.

Between 1993 and 1996 the CarboMedics Top Hat supraannular aortic valve was implanted in 41 patients at the Wessex Cardiothoracic Centre (age, 39 to 74 years; mean, 61.3+/-8.9 years). Comparisons of annular dimensions made at surgery indicate that conventional annular valve replacement would have required at least a size smaller valve. This was particularly marked when a prosthetic mitral valve was in place. Operative mortality was 2.4%. There were also three late deaths. Echocardiography before and after symptom-limited treadmill testing has been performed in 21 patients. The mean time to follow-up was 16.1 months. The Doppler-derived indices of forward flow pre- and postexercise were expressed as mean+/-standard deviation. For 23-mm valves the values were: peak valve gradient 21.43+/-7.46 mm Hg and 35.86+/-14.4 mm Hg, aortic valve area 1.13+/-0.39 cm2 and 1.24+/-0.54 cm2. For 21-mm valves the values were: peak valve gradient 24.84+/-8.2 mm Hg and 31.29+/-5.84 mm Hg, aortic valve area 1.08+/-0.44 cm2 and 0.95 +/-0.2 cm2. The Top Hat valve has a good hemodynamic profile at rest and during exercise. Surgical considerations make it particularly useful in patients with a small aortic annulus and in patients undergoing combined aortic and mitral valve replacement.

Adult↗
PubMed1997

Effect of ovariectomy and steroid hormone replacement on the recovery of arterial blood pressure following haemorrhage in anaesthetized Brattleboro rats.

There is increasing evidence that ovarian steroids inhibit vascular responsiveness to the neurohypophysial hormone vasopressin. The present study examined the recovery of the arterial blood pressure following a single (2 ml/100 g body weight) haemorrhage in ovariectomized (OVX) Brattleboro rats with hereditary hypothalamic diabetes insipidus (BDI) and rats of the parent Long Evans (LE) strain. Some groups of OVX rats received subcutaneous implants of either 17 beta-oestradiol (E2) or progesterone 7 days prior to haemorrhage. The arterial blood pressure recovery immediately following haemorrhage was significantly impaired in both groups of steroid-treated OVX LE rats compared with the OVX controls (both comparisons P < 0.05). The impairment in blood pressure recovery seen in the steroid-replaced OVX LE rats was similar to that seen in pro-oestrous rats (when ovarian steroid levels are raised) compared with male rats of this strain (P < 0.05). In contrast, ovariectomy with or without steroid replacement in BDI rats had no further effect on the already attenuated recovery of arterial blood pressure after haemorrhage in this strain. Heart rate responses to haemorrhage also showed strain differences, which were dependent on steroid treatment. Pro-oestrous female LE rats showed a small decrease in heart rate after haemorrhage, followed by a recovery process, and this initial bradycardia was markedly enhanced in the OVX steroid-treated animals. In contrast, untreated OVX LE rats showed an initial and sustained increase in heart rate which was significantly higher than in the steroid-treated OVX animals (P < 0.05). All BDI rats, irrespective of treatment, consistently showed an increased heart rate after haemorrhage. In conclusion, ovarian steroid replacement in OVX LE, but not vasopressin-deficient BDI, rats was associated with an attenuated pressor recovery after haemorrhage. This provides further evidence for the existence of an important inhibitory interaction between ovarian steroids and vasopressin. The initial decrease in heart rate observed in pro-oestrous and steroid-treated OVX LE rats after haemorrhage also appears to be related to an ovarian steroid-vasopressin interaction.

Animals↗
PubMed1996

A comparative study of miniplates used in the treatment of mandibular fractures.

The purposes of this study were to investigate the differences in mechanical properties of major miniplating systems used for noncompression miniplate osteosynthesis of mandibular fractures and to determine whether these properties influence treatment outcome. The study was conducted in two parts. First, six of the major miniplate systems currently used at the Royal Adelaide Hospital were subjected to bending tests at the University of Adelaide Engineering Department to quantify the relative stiffness of each plate. Second, a prospective sample of patients presenting with mandibular fractures was analyzed. These patients were treated with a variety of the miniplating systems. The results of treatment as a whole were compared to identify any direct benefit consequent on the miniplate selected. While significant differences in stiffness were identified between the plating systems, no significant differences in treatment outcome were identified, between the noncompression plates employed. Since no observable benefits have been identified by choice of miniplate, selection should be based on surgical preference, biocompatibility, CT compatibility and unit cost. Because of the variations in materials, design, properties, CT compatibility, and unit cost, it is important not to regard all miniplates as equal and interchangeable.

Biocompatible Materials↗
PubMed1995

Biological valves beyond fifteen years: the Wessex experience.

Between 1975 and 1979, 443 biological valves (298 Carpentier-Edwards, 134 homograft, and 11 Hancock valves) were implanted in 415 patients (age, 16 to 77 years; mean, 59 years) with an operative mortality of 2.9%. Total follow-up was 4,248 patient-years. Overall event-free survival was 60% +/- 1.5% (standard deviation) at 10 years and 29% +/- 1.4% at 15 years. Ten-year and 15-year event-free survival were 72% +/- 3.4% and 41% +/- 3.3% for aortic homografts, 62% +/- 3% and 33% +/- 2.8% for isolated aortic xenografts, and 43% +/- 3.5% and 14% +/- 3.0% for isolated mitral xenografts. Freedom from structural valve degeneration was 87% +/- 1.3% and 63% +/- 2.5% for all patients at 10 and 15 years, respectively, 86% +/- 2.7% and 58% +/- 4.1% for aortic homografts, 93% +/- 1.8% and 76% +/- 5.1% for aortic xenografts, and 75% +/- 4.0% and 47% +/- 7.4% for mitral xenografts. Of the 110 remaining patients, echocardiography was performed in 61 patients (23 aortic xenograft, 24 aortic homograft, 9 mitral xenograft, and 5 tricuspid xenograft) between 14 and 17 years after implantation. An early diastolic murmur was heard in 57% of all aortic valve replacements (AVRs) 62.5% of homograft AVRs, and 52% of xenograft AVRs. Echocardiographically, aortic regurgitation was detected in 79%, 83%, and 74% of all AVRs, homografts, and xenografts, respectively. Aortic stenosis was present clinically in 11% of all AVRs, 4% of homograft AVRs, and 17% of xenograft AVRs.(ABSTRACT TRUNCATED AT 250 WORDS)

Actuarial Analysis↗
PubMed1994

The relationship between fracture severity and complication rate in miniplate osteosynthesis of mandibular fractures.

There are many factors influencing the outcome of mandibular fracture management; however, the relationship between fracture severity and complication rate has only been recognised intuitively due to the absence of an accepted system of classification of the severity of these fractures. In 1989 Cooter and David described the alpha numeric system of computer based coding for craniofacial fractures. Using this system, a prospective sample of 324 patients with mandibular fractures presenting to the Royal Adelaide Hospital was coded for fracture severity and their progress followed with respect to complication rate. A strong correlation between complication rate and fracture severity was established.

Bacterial Infections↗
PubMed1994

Patterns of mandibular fractures in Adelaide, South Australia.

Facial fractures are exceedingly common, and fractures of the mandible are the most common facial fracture. Over the past two decades a changing trend in the aetiology of these fractures has been apparent, with a decline in the percentage resulting from motor vehicle trauma, and an increase in the percentage resulting from assaults. A 3 year prospective study of 324 patients presenting to the Royal Adelaide Hospital with mandibular fractures was conducted and the patient groups, influence of alcohol, aetiology and type of fracture were examined and compared with other large series from around the world.

Accidents, Traffic↗
PubMed1992

Aggressive surgical management of sleep apnea syndrome in the syndromal craniosynostoses.

Obstructive sleep apnea syndrome (OSAS) frequently develops in patients with craniosynostosis and associated midfacial stenosis. In the past, conservative measures or tracheostomy have been used to manage this condition. Although the course of OSAS in these patients is multifactorial, a major factor is the marrow nasopharyngeal space. Aggressive surgical intervention to enlarge the nasopharyngeal space can reduce the severity of OSAS and therefore avoid the need for tracheostomy. Surgical approaches include adenotonsillectomy, uvulopalatopharyngoplasty, and midface advancement.

Child, Preschool↗
PubMed1991

Crouzon twins with cloverleaf skull malformations.

We describe unique monozygotic twins with Crouzon's disease and cloverleaf-shaped skull deformities who have been closely followed since birth. Their abnormal skull shapes were identified during antenatal ultrasound examination. The twins had gross exophthalmos and hydrocephalus with papilledema, so early calvarial decompression surgery was required. Although born to healthy parents of normal appearance, a third cousin of the twins had a milder form of Crouzon's disease, and there was a family history of high-arched palate on the twins' paternal side. Because Crouzon's disease is an uncommon condition and the cloverleaf skull shape is unusual in patients with Crouzon's disease, identical twins with this constellation of deformities must be exceptionally rare.

Airway Obstruction↗
PubMed1991

Craniofacial clefting and sutural dystopia.

Sutural anomalies in conjunction with craniofacial clefting are unusual. A case of median frontal clefting is presented in which there was an absence of a normal metopic suture and replacement by paramedian frontal sutures. The association of an underlying brain anomaly, with attendant surgical difficulties, is noted, as are the radiological techniques of preoperative diagnosis.

Abnormalities, Multiple↗
PubMed1990

High dose eicosapentaenoic acid ethyl ester: effects on lipids and neutrophil leukotriene production in normal volunteers.

1. A 93% pure ethyl ester of eicosapentaenoic acid was investigated for tolerability and biochemical effects on neutrophil leukotriene synthesis and plasma lipoproteins when given in high dose. Six healthy volunteers received 6 g eicosapentaenoic acid ethyl ester daily for 6 weeks, followed by a 4 week wash-out and then 18 g daily for 6 weeks. 2. There was inhibition of neutrophil leukotriene B4 and 5-hydroxyeicosatetraenoic acid synthesis, with no significant differences between low and high dose. 3. There was a dose dependent increase in leukotriene B5 and 5-hydroxyeicosatetraenoic acid acid synthesis. 4. Plasma triglycerides were reduced maximally on 6 g daily, with no greater suppression at 18 g daily. 5. Plasma cholesterol was only suppressed significantly at 18 g daily. 6. The 6 g daily dose was well tolerated but the 18 g daily dose produced diarrhoea and steatorrhoea.

Adult↗
PubMed1987

Pro & con: staff development vs in-service training. Staff development.

Staff development integrates the needs of the individual and the organization in a growth-oriented approach to continuing education. Through this process, the technologist becomes intrinsically motivated to meet the challenge of change while contributing to the accomplishment of organizational goals.

Hospital Departments↗
PubMed1981

Multiple features analysis of intervocalic English plosives.

A controlled study involving a multi-feature acoustic analysis of intervocalic English plosives has been conducted for the purpose of evaluating acoustic stop features for automatic stop recognition. Both time-domain and frequency-domain features were measured via computer interaction. The resulting discrete density functions allowed for a comparative evaluation of individual (and in some instance conditional or combined) feature contributions to stop identification. This evaluation consisted of the maximum a posteriori probability of a correct identification of either the voicing mode (voiced or voiceless) or the place of articulation (labial, alveolar, or palato-velar) of a stop independent of the talker or of a limited phonetic context. These features included variations on ten acoustic features for voicing mode identification and seven for place-of-articulation identification. The data base for this study consisted of five male and five female talkers producing all permutations of the stops C epsilon /p,t,k,b,d,g/ and vowels V epsilon /i,e,a,u/ in the sentence frame "please say /h 'CVt/ again." While the results indicate that the acoustic features of burst/formant-onset frequency and voice onset time (VOT) are the two single most salient features for stop identification, several additional features are also shown to provide important redundancy for identification. The often overlooked time-domain features of "double-burst release" and "voicing during stop closure" were found to be particularly useful in providing such redundancy.

Adult↗
PubMed1979

Tempo of spectrum change as a cue in speech-sound discrimination by infants.

Six- to seven-month-old infants were tested on their ability to discriminate among three speech sounds which differed on the basis of formant-transition duration, a major cue to distinctions among stop, semivowel and diphthong classes. The three speech sounds, [see text] were produced in two different ways. The stimuli for one experiment were two-formant synthetic tokens which differed in formant-transition duration. The stimuli for a second experiment was produced with a computer-modification technique which artificially shortened or lengthened the formant-transition portion of a naturally produced [see text], resulting in tokens of [see text]. The discrimination procedure involved visual reinforcement of a head-turn response following a change from a repeating background stimulus to a contrasting stimulus. Infants in both experiments discriminated [see text]; evidence for [see text] discrimination was obtained for the "computer modified" tokens only. These findings are discussed in terms of possible mechanisms underlying speech perception in infancy.

Cues↗