Biomedical subjects
Susan Thomas
Publications and source records attributed to Susan Thomas.
Clonidine increases duration of bupivacaine caudal analgesia for ureteroneocystostomy: a double-blind prospective trial.
PURPOSE: We evaluated whether clonidine, when added to bupivacaine, would significantly prolong caudal analgesia and decrease opioid requirements in children undergoing ureteroneocystostomy. MATERIALS AND METHODS: A total of 35 children 1 to 10 years old undergoing ureteroneocystostomy received a standardized regimen of general anesthesia, and were randomized to receive a preincision caudal block consisting of either 1 ml/kg 0.125% bupivacaine (controls) or 1 ml/kg 0.125% bupivacaine with 1 microg/kg clonidine (treatment group). Caudal solutions also contained 1:400,000 epinephrine. Following the surgical procedure a second caudal block was performed with half of the original dose of medications. Caregivers were blinded to which caudal solution was administered. Postoperative outcome measures included pain scores, morphine requirements, duration of caudal analgesia and sedation scores. Statistical analysis was performed using ANOVA. RESULTS: The 2 study groups were similar for mean age, weight and length of surgical procedure. Two patients in the control group were excluded because of protocol violation. Intravenous morphine requirements for rescue therapy were 0.02 mg/kg in the postanesthesia care unit and 0.1 mg/kg on postoperative day 1 for the treatment group, compared to 0.05 mg/kg and 0.2 mg/kg, respectively, for controls (p <0.05). Mean interval from anesthesia finish time to first administered dose of morphine was 8.0 hours for the treatment group and 3.9 hours for controls (p = 0.01). Five of 18 patients in the clonidine-bupivacaine group received no postoperative morphine, compared to 1 of 15 in the bupivacaine group. No patient had development of hemodynamic instability, respiratory depression or sedation requiring treatment. CONCLUSIONS: The addition of clonidine to bupivacaine significantly increases the duration of caudal analgesia and decreases postoperative morphine requirements in children undergoing ureteroneocystostomy.
Assessment of risk factors for emergence distress and postoperative behavioural changes in children following general anaesthesia.
BACKGROUND: Emergence distress commonly occurs in children recovering from the immediate effects of general anaesthesia. This study was performed to (1) examine whether parental presence in the operating room during emergence from anaesthesia reduces the incidence or severity of emergence distress behaviour, and (2) assess psychosocial risk factors, including child temperament and sleep behaviour, for development of emergence distress. METHODS: A randomized and controlled trial of parental presence at emergence was conducted in 100 ASA class I and II children having general anaesthesia for inguinal or penile surgery. Children in the study group had a parent present at induction and emergence of anaesthesia, while children in the control group had a parent present only at induction. Emergence and postanaesthesia care unit (PACU) behaviour was monitored using both the Operating Room Behaviour Rating Scale (ORBRS) and a 7-point Likert type cooperation scale. RESULTS: One-way anovas showed no significant differences between the control group and the study group on emergence distress behaviour. The frequency of negative postoperative behavioural changes at 1 and 4 weeks postsurgery was low in both groups. Children described as clingy/dependent (chi2 = 5.57, P < 0.06) and children with frequent temper tantrums (chi2 = 7.44, P < 0.02) were more likely to have emergence distress behaviour. CONCLUSIONS: Parental presence during emergence from anesthesia did not decrease the incidence or severity of emergence distress behaviour in children. Young children and children with a history of temper tantrums or separation anxiety may be more likely to develop such behaviour.
Immunization of children after solid organ transplantation.
The array of immunizations commonly used in childhood has risen in an attempt to prevent many of the potentially serious infections of infancy and childhood. In this article, the authors provide rational guidelines for vaccination of these children. The authors briefly review the susceptibilities caused by immunosuppression in these patients, discuss the problems with various immunizations, and make individual recommendations regarding the use of each vaccine. Most recommendations are based on inferences from populations that may not be directly comparable to the transplantation population (patients with HIV or cancer or patients who have undergone bone marrow transplant), from case reports, and from small series of patients. The best recommendations ultimately must await the results of controlled trials of immunization.
Cognitive and physiologic correlates of subclinical structural brain disease in elderly healthy control subjects.
CONTEXT: Healthy elderly persons commonly show 4 types of change in brain structure-cortical atrophy, central atrophy, deep white-matter hyperintensities, and periventricular hyperintensities-as forms of subclinical structural brain disease (SSBD). OBJECTIVES: To characterize the volumes of SSBD present with aging and to determine the associations of SSBD, physiology, and cognitive function. DESIGN: Cross-sectional study. SETTING: University of California, Los Angeles, Neuropsychiatric Institute. SUBJECTS: Forty-three community-dwelling healthy control subjects, aged 60 through 93 years. MAIN OUTCOME MEASURES: Volumetric magnetic resonance imaging, neuropsychological testing, and quantitative electroencephalographic coherence (functional connectivity) between brain regions. RESULTS: Regression models demonstrated significant relationships between SSBD volumes, age, cognitive performance, and connectivity. Cortical and central atrophy and periventricular hyperintensities had significant associations with age while deep white-matter hyperintensities did not. Posterior atrophy showed stronger associations with age than did anterior atrophy. Only a subset of subjects at older ages showed large SSBD volumes; older subjects primarily showed increasing variance of SSBD. Although all subjects scored within the normal range on cognitive testing, SSBD volume was inversely related to performance, most notably on the Trail-Making Test part B and the Shipley-Hartford Abstract Reasoning test. Coherence had significant associations with SSBD. Path analysis supported mediation of the effects of deep white-matter hyperintensities and periventricular hyperintensities on cognition by altered connectivity. For several measures, cognitive performance was best explained by coherence, and only secondarily by SSBD. CONCLUSIONS: Modest volumes of SSBD were associated with decrements in cognitive performance within the normal range in healthy subjects. Lower coherence was associated with greater volumes of SSBD and increasing age. Path analysis models suggest that brain functional connectivity mediates some effects of SSBD on cognition.
Management of general anaesthesia in infants and children with a history of idiopathic pulmonary haemorrhage.
BACKGROUND: Idiopathic pulmonary haemorrhage in infants is a rare disorder that is endemic to metropolitan Cleveland, Ohio. Since 1993, 32 infants with this disorder were diagnosed and treated at our institution, one of them after developing pulmonary haemorrhage during induction of anaesthesia. Of this population, five patients have undergone a total of 10 general anaesthetics at some time after the initial diagnosis of pulmonary haemorrhage. METHODS: We performed a retrospective chart review of these cases to identify whether any risk factors for anaesthesia-related morbidity were present, to review the anaesthetic technique and to identify morbidity related to residual underlying pulmonary disease. RESULTS: No patients experienced any anaesthesia related complication nor any perioperative respiratory problem. CONCLUSIONS: These data may be useful to anaesthesiologists in other geographical locations since this disorder has been reported in other parts of the USA, and presumably may exist in other areas of the world.
The receptor tyrosine kinase MuSK is required for neuromuscular junction formation in vivo.
Formation of neuromuscular synapses requires a series of inductive interactions between growing motor axons and differentiating muscle cells, culminating in the precise juxtaposition of a highly specialized nerve terminal with a complex molecular structure on the postsynaptic muscle surface. The receptors and signaling pathways mediating these inductive interactions are not known. We have generated mice with a targeted disruption of the gene encoding MuSK, a receptor tyrosine kinase selectively localized to the postsynaptic muscle surface. Neuromuscular synapses do not form in these mice, suggesting a failure in the induction of synapse formation. Together with the results of an accompanying manuscript, our findings indicate that MuSK responds to a critical nerve-derived signal (agrin), and in turn activates signaling cascades responsible for all aspects of synapse formation, including organization of the postsynaptic membrane, synapse-specific transcription, and presynaptic differentiation.
The children of imprisoned parents: a psychosocial exploration.
This study of children's reactions to the imprisonment of a parent identifies temporary behavioral symptoms that commonly follow the incarceration of a parent, as well as antisocial behavior on the part of a few pubertal children. The stigmatizing and traumatizing effects of imprisonment on the spouse and child left behind are discussed, and suggestions for clinical intervention are offered.