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Biomedical subjects

D Cass

Publications and source records attributed to D Cass.

At least 19 recordsLinked to original sources
PubMed2006

An example of psychological adjustment in chronic illness: Hirschsprung's disease.

The aim of this study was to investigate the outcomes after definitive surgical correction for children with Hirschsprung's disease (HD) and the psychosocial impact of HD on the child and family. The total sample comprised 72 children with HD along with their families. The development of a condition-specific questionnaire measured the functional and psychosocial outcomes for children with HD with parental perception of their child's condition. Psychiatric measures were also examined to assess psychiatric morbidity. The greatest functional problem after definitive surgery for HD was faecal soiling (76%). The principle findings of the study were that (1) HD did not have a significant impact on the child's rate of psychiatric morbidity and levels of hopefulness in comparison to the normal population, (2) surgical and psychosocial functioning improved with increasing age and, (3) families remain troubled about their future with HD and dealing with psychosocial difficulties related to the condition (such as distress because of faecal soiling). Specifically, faecal soiling was found to be physically, emotionally and psychosocially distressing complication. Bowel functioning and psychosocial distress improves with increasing age and parental and medical professional support. Despite the significant impairment of faecal continence, we found that children/young adults with HD have minimal psychiatric morbidity, yet experience condition-specific psychosocial problems (e.g. embarrassment and distress/discomfort). HD does not increase the rate of clinical psychiatric morbidity in children and families with HD, but does determine the context of their daily distress and concern.

Adaptation, Psychological↗
PubMed2004

Mortality due to constipation and short-segment Hirschsprung's disease.

We report a case of mortality secondary to constipation. A 12-year-old child with a history of constipation from the age of 9 years presented in moribund condition with intestinal obstruction secondary to idiopathic constipation. He underwent laparotomy and died within 24 h of operation. At postmortem there was no evidence of abnormalities of the enteric nervous system. A 2nd case of early neonatal death from Hirschsprung's disease is presented to demonstrate that short-segment aganglionosis can be detected at postmortem. Enterocolitis can rapidly progress and be fatal in short-segment Hirschsprung's disease.

Child↗
PubMed2003

Hirschsprung's disease: the Australian Paediatric Surveillance Unit's experience.

Hirschsprung's disease (HD) was introduced into the Australian Paediatric Surveillance Unit (APSU) system in 1996 with the objective to collect data on demographics, incidence, family history, associated anomalies, clinical features, investigation, and surgical treatment in Australia. Children under 15 years of age with HD (confirmed by biopsy) were entered into a database maintained at The Children's Hospital at Westmead in Sydney. Nationwide, 127 children with HD were reported from January 1997 to December 2000, and near-complete information was available on 126. Neonatal presentation was seen in 114 cases (90%), whereas 12 (10%) presented post-neonatally. There was a history of delayed passage of meconium (more than 24 h) in 65 of the 114 patients (57%) who presented in the neonatal period. In those presenting post-neonatally there was no history of delayed passage of meconium. Primary pull-through was performed in 42 of the 82 patients (51%) operated upon. The Soave procedure was performed in 53 of the total 82 (65%) operations and 29 of 42(69%) primary pull-through operations. Pre-operative enterocolitis was seen in 15 of 126 (12%) and postoperative enterocolitis in 17 of 82 (21%) children. The majority of children with HD are diagnosed in the neonatal period (90%). Primary pull-through is becoming more popular (51%). The Soave procedure is the most commonly performed operation (65%) in Australia. Pre- and post-operative enterocolitis is still a significant problem.

Abnormalities, Multiple↗
PubMed2003

Gastroschisis: determinants of neonatal outcome.

This retrospective study elicits information regarding the dependence of neonatal outcome in gastroschisis upon: (1) the mode of delivery, (2) place of birth, (3) time for birth to surgery, (4) method of closure, (5) time from operation to commencement of first enteral feeds. The neonatal intensive care database from five major tertiary centres was used to identify 181 neonates with gastroschisis from 1990 to 2000. There were 8 deaths. There were no significant differences in outcome for infants delivered vaginally (102) versus Caesarean section (79), those born near the tertiary centre (133) as compared to infants born away (48), ones operated within 7 hours (125) compared with those operated after 7 hours (56), with delayed closure (30) versus primary closure (151). Neonates fed within 10 days of operation (85) had significantly lower incidence of sepsis, duration of TPN and hospital stay when compared to those fed after 10 days (96). Early commencement of feeds decreases the incidence of sepsis, duration of total parenteral nutrition (TPN) and hospital stay. Place of delivery, mode of delivery, time to surgery and type of closure do not influence neonatal outcome.

Delivery, Obstetric↗
PubMed2002

Excision duodenoplasty: a new technique for congenital duodenal obstruction.

Slow anastomotic function is a common problem in the management of congenital duodenal obstruction. We describe a simple technique of excision duodenoplasty (ED) that results in a fixed open anastomosis, which facilitates early commencement of feeds and discharge from hospital. A retrospective case-note review (1981-2000) was undertaken to compare the results of ED with side-to-side duodenoplasty (SSD) and diamond-shaped anastomosis (DD). The outcome measures were days to commencement of feeds, duration of total parenteral nutrition (TPN), and length of hospital stay. In ED a 1.0 to 1.5-cm elliptical segment of dilated duodenum is excised. A longitudinal incision is made in the smaller distal duodenum. A side-to-side one-layer anastomosis is performed. The wall of the proximal duodenal stump is thick, and excision of the ellipse keeps the anastomosis open by preventing apposition of the opposing walls. This facilitates good drainage across the anastomosis. The time to onset of feeding was longer after SSD (median 7 days) compared to ED (5 days) and DD (5 days). The total duration of TPN was also longer for SSD (9 days) in comparison to ED (7 days) and DD (7 days). Although the duration of hospital stay was more for SSD (18 days) than ED (13 days) and DD (16 days), this difference was not statistically significant. The ED technique thus gives an equally good result as DD and a better result than SSD. It is simple to perform and to teach.

Analysis of Variance↗
PubMed2001

The Canadian C-spine rule for radiography in alert and stable trauma patients.

CONTEXT: High levels of variation and inefficiency exist in current clinical practice regarding use of cervical spine (C-spine) radiography in alert and stable trauma patients. OBJECTIVE: To derive a clinical decision rule that is highly sensitive for detecting acute C-spine injury and will allow emergency department (ED) physicians to be more selective in use of radiography in alert and stable trauma patients. DESIGN: Prospective cohort study conducted from October 1996 to April 1999, in which physicians evaluated patients for 20 standardized clinical findings prior to radiography. In some cases, a second physician performed independent interobserver assessments. SETTING: Ten EDs in large Canadian community and university hospitals. PATIENTS: Convenience sample of 8924 adults (mean age, 37 years) who presented to the ED with blunt trauma to the head/neck, stable vital signs, and a Glasgow Coma Scale score of 15. MAIN OUTCOME MEASURE: Clinically important C-spine injury, evaluated by plain radiography, computed tomography, and a structured follow-up telephone interview. The clinical decision rule was derived using the kappa coefficient, logistic regression analysis, and chi(2) recursive partitioning techniques. RESULTS: Among the study sample, 151 (1.7%) had important C-spine injury. The resultant model and final Canadian C-Spine Rule comprises 3 main questions: (1) is there any high-risk factor present that mandates radiography (ie, age >/=65 years, dangerous mechanism, or paresthesias in extremities)? (2) is there any low-risk factor present that allows safe assessment of range of motion (ie, simple rear-end motor vehicle collision, sitting position in ED, ambulatory at any time since injury, delayed onset of neck pain, or absence of midline C-spine tenderness)? and (3) is the patient able to actively rotate neck 45 degrees to the left and right? By cross-validation, this rule had 100% sensitivity (95% confidence interval [CI], 98%-100%) and 42.5% specificity (95% CI, 40%-44%) for identifying 151 clinically important C-spine injuries. The potential radiography ordering rate would be 58.2%. CONCLUSION: We have derived the Canadian C-Spine Rule, a highly sensitive decision rule for use of C-spine radiography in alert and stable trauma patients. If prospectively validated in other cohorts, this rule has the potential to significantly reduce practice variation and inefficiency in ED use of C-spine radiography.

Adult↗
PubMed2001

The Canadian CT Head Rule for patients with minor head injury.

BACKGROUND: There is much controversy about the use of computed tomography (CT) for patients with minor head injury. We aimed to develop a highly sensitive clinical decision rule for use of CT in patients with minor head injuries. METHODS: We carried out this prospective cohort study in the emergency departments of ten large Canadian hospitals and included consecutive adults who presented with a Glasgow Coma Scale (GCS) score of 13-15 after head injury. We did standardised clinical assessments before the CT scan. The main outcome measures were need for neurological intervention and clinically important brain injury on CT. FINDINGS: The 3121 patients had the following characteristics: mean age 38.7 years); GCS scores of 13 (3.5%), 14 (16.7%), 15 (79.8%); 8% had clinically important brain injury; and 1% required neurological intervention. We derived a CT head rule which consists of five high-risk factors (failure to reach GCS of 15 within 2 h, suspected open skull fracture, any sign of basal skull fracture, vomiting >2 episodes, or age >65 years) and two additional medium-risk factors (amnesia before impact >30 min and dangerous mechanism of injury). The high-risk factors were 100% sensitive (95% CI 92-100%) for predicting need for neurological intervention, and would require only 32% of patients to undergo CT. The medium-risk factors were 98.4% sensitive (95% CI 96-99%) and 49.6% specific for predicting clinically important brain injury, and would require only 54% of patients to undergo CT. INTERPRETATION: We have developed the Canadian CT Head Rule, a highly sensitive decision rule for use of CT. This rule has the potential to significantly standardise and improve the emergency management of patients with minor head injury.

Adolescent↗
PubMed2001

Antenatal prediction of hypertrophic pyloric stenosis.

This is the first reported case where the diagnosis of hypertrophic pyloric stenosis (HPS) was entertained in the antenatal period and the neonate was followed up in the postnatal period on a prospective basis until the HPS became manifest.

Adult↗
PubMed2001

Canadian CT head rule study for patients with minor head injury: methodology for phase II (validation and economic analysis).

Prospective validation on a new set of patients is an essential test of a new decision rule. However, many clinical decision rules are not prospectively assessed to determine their accuracy, reliability, clinical sensibility, or potential impact on practice. This validation process is important because many statistically derived rules or guidelines do not perform well when tested in a new population. The methodologic standards for a validation study are similar to those described in the article on phase I for derivation studies in the August 2001 issue of Annals of Emergency Medicine. The goal of phase II is to prospectively assess the accuracy, reliability, and acceptability of the decision rule in a new set of patients with minor head injury. This will determine the clinical utility of the rule and is essential if such a rule is to be widely adopted into clinical practice.

Canada↗
PubMed2001

The Canadian CT Head Rule Study for patients with minor head injury: rationale, objectives, and methodology for phase I (derivation).

Head injuries are among the most common types of trauma seen in North American emergency departments, with an estimated 1 million cases seen annually. "Minor" head injury (sometimes known as "mild") is defined by a history of loss of consciousness, amnesia, or disorientation in a patient who is conscious and talking, that is, with a Glasgow Coma Scale score of 13 to 15. Although most patients with minor head injury can be discharged without sequelae after a period of observation, in a small proportion, their neurologic condition deteriorates and requires neurosurgical intervention for intracranial hematoma. The objective of the Canadian CT Head Rule Study is to develop an accurate and reliable decision rule for the use of computed tomography (CT) in patients with minor head injury. Such a decision rule would allow physicians to be more selective in their use of CT without compromising care of patients with minor head injury. This paper describes in detail the rationale, objectives, and methodology for Phase I of the study in which the decision rule was derived. [Stiell IG, Lesiuk H, Wells GA, McKnight RD, Brison R, Clement C, Eisenhauer MA, Greenberg GH, MacPhail I, Reardon M, Worthington J, Verbeek R, Rowe B, Cass D, Dreyer J, Holroyd B, Morrison L, Schull M, Laupacis A, for the Canadian CT Head and C-Spine Study Group. The Canadian CT Head Rule Study for patients with minor head injury: rationale, objectives, and methodology for phase I (derivation). Ann Emerg Med. August 2001;38:160-169.]

Adolescent↗
PubMed2000

Oesophageal atresia in twins.

The twin incidence is higher in infants with oesophageal atresia (OA) than in the general population. The purpose of this study was to review the twin OA information from five institutions and evaluate possible links between the development of OA and the twinning process. Data were compared, combined, and analysed. There was a total of 1,215 infants with OA, of whom 50 were from a twin pregnancy and 1 from a triplet pregnancy. Two sets of twins were concordant for OA. Mean birth weights and gestational ages were lower in the twin infants (P < 0.0005) and survival was lower in twins (65%, P < 0.005) than singletons. The anatomical variant of pure OA without fistula was seen in proportionally fewer twins (4%) than in singletons (7%). Multiple anomalies were present in 40% of twins compared with 33% of singletons, although this did not reach statistical significance. OA in our multicentre population was more common in twins. Several possible mechanisms are put forward to explain the apparent link between twinning and OA. Further analysis of this aspect of OA may aid in understanding the aetiology of this congenital anomaly.

Esophageal Atresia↗
PubMed1999

Vanishing gut in infants with gastroschisis.

Infants born with gastroschisis (GS) in association with intestinal atresia are well described, however, atresia to the extent where none or very little of the midgut remains has rarely been reported. In this paper we present one infant born with a GS defect in combination with total loss of the midgut and another with a tight GS defect with atresia of the proximal and distal midgut at the regions where the bowel had gone through the abdominal wall. On examining these and other case reports in the literature, we realised that there is a GS spectrum, at one end with simple, localised atresia with the rest of the gut exhibiting minimal vascular compromise and at the other a very small or no defect with absence of the entire midgut.

Fatal Outcome↗
PubMed1999

Adverse outcome of congenital diaphragmatic hernia is determined by diaphragmatic agenesis, not by antenatal diagnosis.

BACKGROUND/PURPOSE: The authors studied their congenital diaphragmatic hernia (CDH) cases retrospectively to ascertain if classical CDH and diaphragmatic agenesis (DA) have separate clinical manifestations, whether antenatally diagnosed cases behave differently from those not diagnosed antenatally, and if antenatal diagnosis before 25 weeks carries a worse prognosis. METHODS: The authors performed a retrospective review of 23 infants with CDH treated at their institution between January 1996 and March 1999. The patients were divided into 3 groups that were analyzed: DA and classical CDH, antenatally diagnosed and nonantenatally diagnosed, and antenatally diagnosed before 25 weeks and after 25 weeks. RESULTS: There were 8 cases of DA and 11 cases of classical CDH. Four infants died without operation and could not be classified. Neonates with DA had significantly longer mean duration of preoperative stabilization compared with classical CDH (5.25+/-2.76 days v 1.36+/-1.0 days) and postoperative mechanical ventilatory support (15.7+/-3.0 days v 4.9+/-3.0 days). Fifty percent of DA patients died; all classical CDH patients survived. Twelve cases were diagnosed antenatally, 6 before 25 weeks' gestation. Antenatally diagnosed cases had no statistically significant difference in mortality rates from those not diagnosed antenatally; 50% of those diagnosed before 25 weeks survived. CONCLUSIONS: DA cases require more preoperative preparation and postoperative ventilation and have a bad prognosis compared with classical CDH. Antenatal diagnosis of CDH does not convey a different prognosis. Fifty percent of CDH patients with antenatal diagnosis before 25 weeks survive.

Diaphragm↗
PubMed1999

Fetal defaecation: is it a normal physiological process?

It has been long known that the late gestation human fetus passes meconium in response to hypoxia. However, there is good evidence, from amniotic fluid studies measuring bile pigment and enteric enzyme content, to suggest that passage of meconium is a normal physiological event in the second trimester. Similarly there is some indirect evidence that fetal defaecation is a normal physiological process in the third trimester. However, this evidence is less strong, and it is safer to assume that in most cases meconium staining of liquor at this time is associated with fetal hypoxia. Dilation of the rectosigmoid portion of the distal bowel found in newborn infants with anorectal malformations supports the hypothesis that fetal colonic peristalsis and defaecation is a normal physiological process.

Adaptation, Physiological↗
PubMed1999

Microvascular "supercharged" cervical colon: minimizing ischemia in esophageal reconstruction.

Traditional colonic reconstruction of the esophagus is performed by cervical transposition of an isolated segment of colon with the vascular supply derived from one of the mesenteric colic vessels. The transposed cervical portion of the colon is farthest from the vascular supply and is at risk of ischemic injury. Despite notable risk of ischemic complications to the colonic neoesophagus, reports advocating a "supercharged" microvascular augmentation of the vascular supply to the cervical portion of the colon remain few in number. Herein, the ischemic complications associated with traditional transposition of the colon for esophageal reconstruction are reviewed, and avoidance by microvascular "supercharging" of the cervical colon is advocated under particular circumstances. The authors present a case of colonic interposition for esophageal replacement requiring a cervical microvascular anastomosis for survival of the transferred colon.

Adult↗
PubMed1999

Automated purification and quantification of oligonucleotides.

We have developed automated methods for the trityl-on purification and quantification of synthetic oligonucleotides. Oligonucleotide purification is by solid-phase extraction cartridges using Amberchrom CG-50 resin on an XYZ-axis robotic system. Quantification is by OD260nm using an online UV-visible spectrophotometer with sipper. The purification of 20 oligonucleotides requires 5 min of user set-up time, plus 20 min per sample of robot time. For a 15-25-mer at the 40 nmol scale of synthesis, the method gives a yield of 2.8 ODs from a load of 10.1 OD, i.e., a 28% average yield. Oligonucleotides purified by this method have proven to be successful for primers for automated DNA sequencing.

Autoanalysis↗
PubMed1998

Human factor IX corrects the bleeding diathesis of mice with hemophilia B.

Mice with hemophilia B have been engineered using gene targeting techniques. These animals exhibit severe factor IX deficiency and a clinical phenotype that mirrors the human disease. We have bred the founder animals onto two different strains of mice, C57B1/6 and CD-1, and have sought to determine whether adenoviral vectors expressing human factor IX could correct the bleeding diathesis of mice with hemophilia B. Initial experiments showed that purified plasma-derived human factor IX added to murine factor IX-deficient plasma resulted in complete correction of the activated partial thromboplastin time (aPTT), and that injection of 10(11) particles of an adenoviral vector expressing human factor IX resulted in normalization of a modified aPTT in mouse plasma. As an additional method of assessing the function of human factor IX in the murine coagulation system, bleeding times were performed in normal, hemophilic, and adenoviral-treated hemophilic mice. By two different bleeding-time techniques, the treated hemophilic mice gave values identical to normal littermate controls, whereas the untreated hemophilic mice exhibited heavy blood loss and prolonged bleeding. There was a marked difference in antibody formation in the two strains of mice; 100% of the hemophilic CD-1 mice formed antibodies to human factor IX, but none of the C57B1/6 mice did. These data suggest that the C57B1/6 hemophilic mice will be more useful for gene transfer studies, while the CD-1 hemophilic mice may be of greater utility in studying the development of inhibitors.

Adenoviridae↗