PubMed Health⌕ Search

Biomedical subjects

Christopher Young

Publications and source records attributed to Christopher Young.

10 recordsLinked to original sources
PubMed2006

A prospective open trial of guanfacine in children with pervasive developmental disorders.

OBJECTIVE: A common complaint for children with pervasive developmental disorder (PDD) is hyperactivity. The purpose of this pilot study was to gather preliminary information on the efficacy of guanfacine in children with PDD and hyperactivity. METHODS: Children with PDD accompanied by hyperactivity entered the open-label trial if there was a recent history of failed treatment with methylphenidate or the child did not improve on methylphenidate in a multisite, placebo-controlled trial. RESULTS: Children (23 boys and 2 girls) with a mean age of 9.03 (+/-3.14) years entered the open-label trial. After 8 weeks of treatment, the parent-rated Hyperactivity subscale of the Aberrant Behavior Checklist (ABC) went from a mean of 31.3 (+/-8.89) at baseline to 18.9 (+/-10.37) (effect size = 1.4; p < 0.001). The teacher-rated Hyperactivity subscale decreased from a mean of 29.9 (+/-9.12) at baseline to 22.3 (+/-9.44) (effect size = 0.83; p < 0.01). Twelve children (48%) were rated as Much Improved or Very Much Improved on the Clinical Global Impressions- Improvement. Doses ranged from 1.0 to 3.0 mg/day in two or three divided doses. Common adverse effects included irritability, sedation, sleep disturbance (insomnia or midsleep awakening), and constipation. Irritability led to discontinuation in 3 subjects. There were no significant changes in pulse, blood pressure, or electrocardiogram. CONCLUSIONS: Guanfacine may be useful for the treatment of hyperactivity in children with PDD. Placebo-controlled studies are needed to guide clinical practice.

Adolescent↗
PubMed2004

Age effects on antidepressant-induced manic conversion.

BACKGROUND: Antidepressant drug therapy can precipitate mania in vulnerable individuals, but little is known about the effects of age on this phenomenon. OBJECTIVE: To pharmacoepidemiologically evaluate the risk of conversion to mania by antidepressant class and patient age. DESIGN, SETTING, AND PATIENTS: Using an administrative national database of more than 7 million privately insured individuals, linked outpatient and pharmacy claims were analyzed for mental health users aged 5 to 29 years (N = 87,920). MAIN OUTCOME MEASURES: The proportion and cumulative hazard of manic conversion were analyzed by antidepressant class and subject age among children, adolescents, and young adults with an anxiety or nonbipolar mood disorder in the United States between January 1, 1997, and December 31, 2001. Manic conversion was defined as a new diagnosis of bipolar illness. RESULTS: During median follow-up of 41 weeks (range, 8-251 weeks), manic conversion occurred in 4786 patients (5.4%). Multivariate analyses using time-dependent Cox proportional hazards models indicated that an increased risk of manic conversion was associated with antidepressant category vs no antidepressant exposure (hazard ratios: 2.1 for selective serotonin reuptake inhibitors, P<.001; 3.8 for "other" antidepressants, P<.001; and 3.9 for tricyclic antidepressants, P =.002). Antidepressant x age interactions revealed inverse age effects for selective serotonin reuptake inhibitors and other antidepressants (beta = -.05; P<.001 for both) but not for tricyclic antidepressants (beta = -.02; P =.25). Peripubertal children exposed to antidepressants were at highest risk of conversion (number needed to harm: 10 [95% confidence interval, 9-12] among 10- to 14-year-olds vs 23 [95% confidence interval, 21-25] among 15- to 29-year-olds). CONCLUSIONS: Patient age is an effect modifier on the risk of antidepressant-associated manic conversion. Treatment with antidepressants is associated with highest conversion hazards among children aged 10 to 14 years.

Adolescent↗
PubMed2004

Dexmedetomidine pharmacodynamics: Part II: Crossover comparison of the analgesic effect of dexmedetomidine and remifentanil in healthy volunteers.

BACKGROUND: Dexmedetomidine is a highly selective alpha2-adrenoceptor agonist used for short-term sedation of mechanically ventilated patients. The analgesic profile of dexmedetomidine has not been fully characterized in humans. METHODS: This study was designed to compare the analgesic responses of six healthy male volunteers during stepwise target-controlled infusions of remifentanil and dexmedetomidine. A computer-controlled thermode was used to deliver painful heat stimuli to the volar side of the forearms of the subjects. Six sequential 5-s stimuli (ranging from 41 degrees to 50 degrees C) were delivered in random order. The recorded visual analog scale was used to fit an Emax model. RESULTS: Compared to baseline, remifentanil infusions resulted in a right shift of the sigmoid curve (increased T50, the temperature producing a visual analog scale score of 50% of the maximal effect, from 46.1 degrees C at baseline to 48.4 degrees and 49.1 degrees C during remifentanil infusions) without a change of the steepness of the curve (identical Hill coefficients gamma during baseline and remifentanil). Compared to baseline, dexmedetomidine infusions resulted in both a right shift of the sigmoid curve (increased T50 to 47.2 degrees C) and a decrease in the steepness of the curve (decreased gamma from 3.24 during baseline and remifentanil infusions to 2.45 during dexmedetomidine infusions). There was no difference in the pain responses between baseline and after recovery from remifentanil infusions (identical T50 and gamma). CONCLUSION: As expected, dexmedetomidine is not as effective an analgesic as the opioid remifentanil. The difference in the quality of the analgesia with remifentanil may be a reflection of a different mechanism of action or a consequence of the sedative effect of dexmedetomidine.

Adult↗
PubMed2003

Omega-3 fatty acids in mood disorders: an overview.

This review addresses the potential role of omega-3 fatty acids in mood disorders, from the biochemical rationale for their use to the growing body of data supporting their clinical efficacy.

Bipolar Disorder↗
PubMed2002

Management of large bowel obstruction in advanced ovarian cancer with intraluminal stents.

BACKGROUND: While most patients with advanced ovarian cancer can achieve prolonged remission with surgery and chemotherapy, eventually most will recur. Commonly bowel obstruction will complicate their recurrence, usually heralding the terminal phase of their disease. Standard management of bowel obstruction has involved surgical intervention after a period of conservative medical management. Unfortunately, many patients submitted for surgery do not derive benefit from such an approach, spending the majority of their remaining life in the hospital or recovering from the surgery. CASES: Two cases of patients with large bowel obstruction resulting from advanced and recurrent ovarian cancer are presented. In the first case, a rectal stent was decided upon as the appropriate management as she was failing first-line therapy, with little likelihood of recovering from a laparotomy. In the second case a large recurrent infected tumor mass had already been debulked, but was continuing to cause obstructive symptoms. In both cases immediate relief of their gastrointestinal symptoms was achieved. CONCLUSIONS: In patients with large bowel obstruction secondary to extrinsic compression, useful palliation can be achieved with a colonoscopically placed endoluminal stent.

Colonic Diseases↗
PubMed2002

Lithium dilution cardiac output measurement: a clinical assessment of central venous and peripheral venous indicator injection.

OBJECTIVE: The lithium indicator dilution technique has been shown to measure cardiac output (CO) accurately by using central venous injection of lithium chloride (Li-CCO). This study aimed to compare the measurement of CO by using peripheral venous administration of lithium chloride (Li-PCO) with Li-CCO. DESIGN: Prospective, observational human study. SETTING: Surgical intensive care unit. PATIENTS: Thirty-one patients were studied after major surgery. All patients had arterial, central, and peripheral venous catheters. A total of 24 patients had pulmonary artery catheters. MEASUREMENTS: Serial measurements of Li-CCO and Li-PCO were made during hemodynamically stable conditions. CO was also measured using thermodilution (TDCO) when a pulmonary artery catheter was present. Data were analyzed by linear regression, the generalized estimating equation, and the comparison method described by Bland and Altman. MAIN RESULTS: There were 93 Li-CCOs, 93 Li-PCOs, and 216 TDCOs recorded. The ranges of COs were similar: Li-CCO, 2.36-11.52 L/min (mean, 5.22 L/min; n = 31); Li-PCO, 1.63-9.99 L/min (mean, 5.22 L/min; n = 31), and TDCO, 3.28-10.4 L/min (mean, 5.75 L/min; n = 24). There was good linear correlation between Li-CCO and Li-PCO (R2 =.845). The mean difference for Li-CCO-Li-PCO was very small and insignificant (p =.97), and the limits of agreement were acceptable (mean difference +/- sd, 0.0005 +/- 0.64 L/min). The mean difference for Li-CCO-Li-PCO was smaller if the peripheral injection site was proximal rather than distal to the wrist (p =.053). Li-PCO and Li-CCO values were lower than simultaneously obtained TDCO measurements (Li-PCO-TDCO, -0.538 +/- 0.95 L/min, p =.003; Li-CCO-TDCO, -0.526 +/- 0.67 L/min, p =.0001). CONCLUSIONS: Li-PCO gives a measurement that agrees well with Li-CCO. Accuracy of Li-PCO is probably improved if a proximal arm vein is used. Li-PCO provides accurate measurements of CO without the risks of pulmonary artery or central venous catheterization.

Cardiac Output↗
PubMedDate not supplied

Survival and quality of life after cardiac surgery complicated by prolonged intensive care.

AIM: To determine survival, factors determining survival and evaluate quality of life (QOL) after 1 year, in patients who had prolonged intensive care unit (ICU) stay after cardiac surgery. METHODS: In the year 2001, 804 patients underwent various cardiac procedures utilising cardiopulmonary bypass (CPB). Eighty-nine consecutive patients requiring ICU stay of > or = 5 days constituted the study group, majority of these suffered from multiorgan failure (> 2 organ systems). Survival was determined in the study group after 1 year. Patients with an uncomplicated postoperative course were matched to the survivors in the study group with respect to age, gender, type of surgery, risk scores, and duration of follow-up and constituted the control group. The, Short Form Health Survey was used to assess QOL at the end of 1 year in these patients. QOL was compared between the study group and the control group and to that of general population. RESULTS: Seventy percent of the patients in the study group suffered from failure of at least three organ systems. Mean ICU stay was 13 +/- 3 days (median nine, maximum 53). At the end of 1 year the mortality in the study group was 34%. The independent predictors of mortality were: preoperative cardiac support, lower ejection fraction, higher Parsonnet score, higher Euroscore, pulmonary complications, renal failure necessitating hemofiltration, CNS complications, and failure of three or more organ systems. The QOL was lower in the study group than the control group in all eight dimensions measured (significant in five p < 0.05): Physical function, Role physical, Vitality, Mental health, General health, and Bodily pain. CONCLUSION: One year mortality in patients with prolonged ICU stay after cardiac surgery remains high. Identification of risk factors will help to reduce the mortality with help of regular follow up. The QOL remains low in all dimensions especially those measuring physical aspects and pain.

Adult↗