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Biomedical subjects

S M Green

Publications and source records attributed to S M Green.

At least 37 records · Page 2Linked to original sources
PubMed2000

Does adjunctive midazolam reduce recovery agitation after ketamine sedation for pediatric procedures? A randomized, double-blind, placebo-controlled trial.

STUDY OBJECTIVE: Despite widespread use of adjunctive benzodiazepines during ketamine sedation, their efficacy in reducing recovery agitation in children has never been studied. We wished to characterize the nature and severity of recovery agitation after ketamine sedation in children treated in the emergency department and to determine whether the addition of adjunctive midazolam reduces the magnitude of such recovery agitation. METHODS: The study was a randomized, double-blind, clinical trial of adjunctive midazolam versus placebo during ketamine sedation. We enrolled 104 children aged 12 months to 15 years (median age, 6 years) at a combined university medical center and children's hospital. Subjects received either intravenous midazolam (0.05 mg/kg up to 2 mg) or placebo after intravenous administration of a ketamine loading dose (1.5 mg/kg). Treating physicians and nurses independently noted the presence of crying, hallucinations, and nightmares during recovery and graded recovery agitation by using a 100-mm visual analog scale. Preprocedure agitation and external stimulation during recovery were also graded. The time from ketamine injection until each subject met the recovery criteria was recorded. RESULTS: Fifty-three subjects received midazolam, and 51 received placebo. Potentially confounding variables were similar between the groups. Sedation efficacy, adverse effects, and recovery time were also similar between groups. Interobserver agreement between physician and nurse assessments was substantial. Median physician assessment of recovery agitation was 4 mm (interquartile range, 2 to 19) in the midazolam group and 5 mm (interquartile range, 3 to 14) in the placebo group (difference -1; 95% confidence interval -3 to 2; P =.705). Recovery agitation was moderately correlated with preprocedure agitation (rho=0.486) but not with external stimulation during recovery (rho=0.147). CONCLUSION: Recovery agitation is common but generally of very low magnitude after ketamine sedation in children in the ED. We observed a median physician rating of 5 mm on a 100-mm visual analog scale, a score that we believe to be clinically insignificant. The degree of recovery agitation after ketamine sedation is significantly related to the degree of preprocedure agitation. In this study, concurrent midazolam did not diminish such agitation and had no measurably beneficial effect. Use of adjunctive benzodiazepines in pediatric ketamine sedation appears unnecessary.

Adjuvants, Anesthesia↗
PubMed2000

Predictors of adverse events with intramuscular ketamine sedation in children.

STUDY OBJECTIVE: Ketamine is a safe and effective sedative for emergency department procedures in children. However, the use of ketamine sometimes is associated with airway complications, emesis, and recovery agitation. We wished to identify predictors of these adverse events that clinicians might use to risk-stratify children who are candidates for ketamine sedation. METHODS: We analyzed data from 1,021 ED intramuscular ketamine sedations in children 15 years of age or younger at a university medical center and an affiliated county hospital over a 9-year period. Five potential predictor variables (age, gender, American Society of Anesthesiologists' [ASA] risk classification, quantity of first ketamine dose, and number of ketamine doses administered) were compared between children with and without complications. We used multiple logistic regression analyses to determine the association of these 5 variables with emesis and recovery agitation, and validated these analyses with bootstrap resampling techniques. We compared children with and without airway complications using univariate statistics alone, as there were too few patients with airway complications to support a multivariate analysis. RESULTS: No study variables had significant univariate associations with airway complications (all P values >.40). We found emesis to be associated with increasing age in multivariate analysis (odds ratio [OR] 1.25 per year, bias-corrected 95% confidence interval [CI] 1.17 to 1.34, P<.001). The incidence of emesis was 12. 1% in children aged 5 years or older, and 3.5% in those younger than 5 years (Delta8.6%, 95% CI 4.9% to 12.1%). Recovery agitation was associated with the presence of an underlying medical condition (ie, ASA class > or =2, OR 3.05, bias-corrected 95% CI 1.65 to 7.30, P=.004) and inversely associated with increasing age (OR 0.79 per year, bias-corrected 95% CI 0.69 to 0.89, P<.001). The incidence of recovery agitation was 17.9% in ASA class 1 children and 33.3% in children in ASA class 2 or greater (Delta-15.4%, 95% CI 0.0% to -30. 7%). The incidence of recovery agitation was 12.1% in children aged 5 years or older, and 22.5% in those younger than 5 years (Delta-10. 4%, 95% CI -3.0% to -17.7%). Bootstrap resampling techniques validated the importance of the significant variables identified in the regression analyses. CONCLUSION: No study variable was predictive of ketamine-associated airway complications. Emesis that occurred after ketamine administration was modestly associated with increasing age. Recovery agitation was modestly associated with decreasing age and the presence of an underlying medical condition. The discriminatory power of these variables was low enough as to be unlikely to alter clinical decisions regarding patient selection for ketamine administration. No evidence of a significant ketamine dose relationship was noted for airway complications, emesis, or recovery agitation.

Adolescent↗
PubMed2000

A novel technique for the detailed size characterization of wear debris.

The accurate and detailed characterization of artificial joint wear debris is important in determining both the wear rate of prostheses and understanding the role that the debris plays in the development and progression of aseptic loosening. The novel application of low angle laser light scattering (LALLS) to the particle size characterization of ultra high molecular weight polyethylene (UHMWPE) wear debris is described. The results demonstrate that both ex vivo and in vitro origin wear debris samples, at concentrations typical of those produced via an alkali-digestion retrieval route, can be reproducibly analyzed via LALLS. Because the LALLS route enables particle size analysis of the entire debris sample to be acquired non-destructively and whilst in suspension, artefacts associated with filtering, drying and agglomeration of debris are avoided, in contrast to currently used techniques such as filtration and scanning electron microscopy (SEM) observation.

Journal Article↗
PubMed2000

Findings on disruptive behavior disorders from the first decade of the Developmental Trends Study.

The paper summarizes the first decade of the Developmental Trends Study, a prospective longitudinal study of 177 boys. Initially, they were referred to mental health clinics in Pennsylvania (Pittsburgh), and Georgia (Athens and Atlanta). Since 1987, the boys, their parents, and their teachers have been followed up almost annually. The study is unique because the cooperation rate of participants has remained very high over the years, psychiatric diagnoses were derived from structured interviews (especially disruptive behavior disorders), and many risk factors were measured over the years. The present paper summarizes key findings on the development of disruptive behavior, especially Oppositional Defiant Disorder, Conduct Disorder, and Attention Deficit-Hyperactivity Disorder. The paper also highlights results on risk factors and comorbid conditions of disruptive behaviors.

Attention Deficit Disorder with Hyperactivity↗
PubMed2000

Intratendinous rupture of a flexor tendon graft many years after staged reconstruction: a report of three cases.

Three cases of rupture of a flexor tendon graft many years after surgery are presented. Two cases occurred 12 years after reconstruction and the third case occurred 21 years after reconstruction. Each rupture was intratendinous, just proximal to the flexor tendon sheath in 2 cases and at the proximal edge of the transverse carpal ligament in the third case. Active digital flexion was restored by transfer of the flexor digitorum superficialis from an adjacent finger to the distal tendon stump or by direct end-to-end repair of the rupture site reinforced with an onlay autogenous patch graft. Patients undergoing tendon grafting should be alerted to the possibility of rupture, even many years later.

Adolescent↗
PubMed2000

Physical fighting in childhood as a risk factor for later mental health problems.

OBJECTIVE: The prevalence, persistence, and desistance of boys' physical fighting was examined over a 7-year period. The importance of persistent physical fighting compared with other risk factors in the prediction of later mental health problems was explored. METHOD: One hundred seventy-seven boys, aged 7 to 12 years, who had been referred to clinics for mental health problems were followed up annually for 7 years, with the boys, their parents, and teachers as informants. RESULTS: Agreement among different informants about the boys' fighting tended to be low. The prevalence of fighting over time remained quite similar for different age cohorts. Almost 9 of 10 fighters in year 1 continued to fight in one or more successive years, and about one third of the boys could be classified as persistent fighters. Only 13.1% of the boys desisted in fighting. Boys who desisted, compared with those who persisted, had higher intelligence and their mothers scored lower on measures of antisocial personality disorder. At year 7, persistent fighting was significantly associated with impairment. The prevalence of psychiatric diagnoses in year 7 was 3 times higher for persistent fighters than for nonfighters. Using regression analyses with several control variables, conduct disorder was best predicted by earlier oppositional defiant disorder in year 1 and persistent fighting. Global impairment was best predicted by oppositional defiant disorder in year 1, persistent fighting, and low IQ. Finally, the number of diagnoses at year 7 was best predicted by persistent fighting. CONCLUSION: Physical fighting constitutes a significant mental health risk in referred boys.

Adolescent↗
PubMed2000

Abdominal trauma in infants and children: prompt identification and early management of serious and life-threatening injuries. Part I: injury patterns and initial assessment.

Evaluation of children with abdominal trauma can be a difficult process. Unique anatomic features predispose children to specific injuries and potentially make identification of life-threatening injuries difficult. While Part I of this review discusses the initial assessment and diagnostic testing in children with abdominal trauma, Part II will review specific injuries and ED management of children with possible abdominal trauma. Knowledge of each of these factors will improve the ability of general and pediatric emergency physicians to expeditiously identify children with potential serious injury and initiate appropriate treatment.

Abdominal Injuries↗
PubMed2000

Abdominal trauma in infants and children: prompt identification and early management of serious and life-threatening injuries. Part II: Specific injuries and ED management.

Evaluation of children with suspected abdominal trauma could be a difficult task. Unique anatomic and physiologic features render vital sign assessment and the physical examination less useful than in the adult population. Awareness of injury patterns and associations will improve the early diagnosis of abdominal trauma. Clinicians must have a complete understanding of common and atypical presentations of children with significant abdominal injuries. Knowledge of the utility and limitations of available laboratory and radiologic adjuncts will assist in accurately identifying abdominal injury. While other obvious injuries (eg, facial, cranial, and extremity trauma) can distract physicians from less obvious abdominal trauma, an algorithmic approach to evaluating and managing children with multisystem trauma will improve overall care and help to identify and treat abdominal injuries in a timely fashion. Finally, physicians must be aware of the capabilities of their own facility to handle pediatric trauma. Protocols must be in place for expediting the transfer of children who require a higher level of care. Knowledge of each of these areas will help to improve the overall care and outcome of children with abdominal trauma.

Abdominal Injuries↗
PubMed2000

Effects of a negative pressure venom extraction device (Extractor) on local tissue injury after artificial rattlesnake envenomation in a porcine model.

OBJECTIVES: To determine if a commercially available negative-pressure venom extraction device (Extractor) reduces local tissue injury after artificial rattlesnake envenomation in a porcine model. METHODS: We prospectively studied 10 pigs using a crossover design. After the pigs were anesthetized, 25 mg Crotalus atrox venom was injected obliquely with a 22-gauge needle 7 mm deep into subcutaneous tissues proximal to the ventral hind hoof. Pigs were randomized to receive either the Extractor (applied 3 minutes following envenomation and left in place for 30 minutes) or no Extractor. The protocol was repeated 14 days later by using the alternate treatment group and opposite hind leg for each animal. We measured leg circumference at standardized locations on the hoof, foreleg, and thigh at baseline and then 1, 2, 3, 4, 5, 6, 24, 48, 72, and 96 hours following venom injection. Maximal changes in circumference at 6 hours were compared using the paired t test. Minimum residual swelling at up to 96 hours was similarly compared. RESULTS: Maximal 6-hour swelling was similar with and without the Extractor: the hoof difference with the Extractor was -0.1% (95% CI = -3.4% to 3.2%, P = .95), foreleg difference was 0.3% (95% CI = -4.1% to 4.7%, P = .88), and thigh difference was -2.8% (95% CI = -10.0% to 4.4%, P = .40). Minimum residual swelling at up to 96 hours was also similar with and without the Extractor: hoof difference with the Extractor was 1.2% (95% CI = -5.6% to 8.0%, P = .70), foreleg difference was 0.6% (95% CI = -3.7% to 4.9%, P = .76), and thigh difference was 0.3% (95% CI = -2.4% to 3.0%, P = .81). A circular lesion identical in size and shape to the Extractor suction cup, which later necrosed and resulted in tissue loss, developed where the device had been applied in 2 animals. No such lesions occurred in legs not treated with the Extractor. CONCLUSION: No benefit was demonstrated from Extractor use for artificial rattlesnake envenomation in our animal study. The skin necrosis noted in 2 Extractor-treated extremities suggests that an injury pattern may be associated with the device.

Animals↗
PubMed2000

Compressive radial neuropathies.

Radial neuropathy can have one of several clinical presentations, depending on the level of compression: high radial nerve palsy, PIN palsy, radial tunnel syndrome, and Wartenberg's syndrome. Elucidating the history and progression of symptoms with a physical examination directed at testing individual muscles will determine the approximate anatomic level of radial injury. Identification of a Tinel's sign will often locate the site of compression. Electrodiagnostic studies can confirm the diagnosis in a radial motor neuropathy, but are unreliable in radial tunnel syndrome and sensory radial nerve compression. A trial of nonsurgical treatment is warranted in all cases except those with progressive motor weakness or palsy. Patients who do not respond or continue to progress despite conservative treatment are candidates for surgical decompression.

Diagnosis, Differential↗
PubMed2000

Comparison of high-fat and high-carbohydrate foods in a meal or snack on short-term fat and energy intakes in obese women.

The present study aimed to compare the action of high-fat and high-carbohydrate (CHO) foods on meal size (satiation) and post-meal satiety in obese women. A within-subjects design was used; each participant received all four nutritional challenges. Fifteen healthy obese women (age 21-56 years, BMI 35-48 kg/m2) participated; thirteen completed all four test days. On two test days, participants were exposed to a nutritional challenge comprising an ad libitum high-fat or high-CHO lunch. On the other two test days they were exposed to a challenge comprising an ad libitum sweet high-fat or high-CHO mid-afternoon snack. Energy and macronutrient intakes were measured at each eating episode. Visual analogue rating scales were completed periodically to record subjective feelings of appetite. When offered a high-CHO selection of foods at lunch and mid-afternoon participants consumed less energy than when offered a high-fat selection. However, post-meal satiety was similar. Total test-day energy intake was significantly higher when high-fat foods were consumed at lunch, but not as a snack. Consumption of high-fat foods at a lunch and snack increased the amount of fat consumed over the whole test day. In conclusion, energy intake of an eating episode was influenced by nutrient composition in this group of obese women. Consumption of high-fat foods at lunch or as a snack led to overconsumption relative to high-CHO foods. However, high-fat foods at meals may have greater potential to influence daily intake than at snacks, probably because meals are larger eating episodes and therefore give greater opportunity to overconsume.

Adult↗
PubMed1999

Fatty acid ethyl and methyl ester synthases, and fatty acid anilide synthase in HepG2 and AR42J cells: interrelationships and inhibition by tri-o-tolyl phosphate.

Synthesis of fatty acid ethyl esters (FAEEs), fatty acid methyl esters (FAMEs), and fatty acid anilides (FAAs) in humans and/or experimental animals and in vitro have been reported by us and other investigators. In previous studies, we have demonstrated that fatty acid ethyl ester synthase (FAEES), purified from rat liver microsomes, is structurally and functionally identical to the rat liver microsomal carboxylesterase (pI 6.1) and suggested a role in the conjugation of a variety of xenobiotic alcohols with endogenous fatty acids (B. S. Kaphalia, R. R. Fritz, and G. A. S. Ansari, Chem. Res. Toxicol. 11, 211-218, 1997). However, hepatic FAEES was found to be structurally and functionally different from that of pancreas. Therefore, the present study was undertaken to determine structural and functional interrelationships among the enzyme(s) involved in the synthesis of FAEEs, FAMEs, and FAAs, in HepG2 and AR42J cells using tri-o-tolyl phosphate (TOTP), a specific inhibitor for beta-esterases. Synthesis of FAEEs, FAMEs, and FAAs, studied in the HepG2 cells, was found to be dose- and time-dependent following incubation with methanol, ethanol, or aniline, respectively. Approximately 86-90% inhibition of FAEE, FAME, and FAA synthesizing activities was found in HepG2 cells following exposure to 2.5 microM TOTP. Identical profiles of dose- and time-dependent inhibition of FAEE, FAME, and FAA synthesizing activities by TOTP in HepG2 cells suggest that synthesis of FAEEs, FAMEs, and FAAs is catalyzed by the same enzyme(s). However, FAEE, FAME, and FAA synthesizing activities in AR42J cells could not be inhibited by TOTP under similar experimental conditions. A differential pattern of p-nitrophenyl acetate hydrolyzing activity (a measure of esterase activity) similar to that of fatty acid ester/anilide synthesizing activities was observed in the two cell lines. These results are further substantiated by the presence of approximately 60 kDa (subunit molecular weight) protein in the postnuclear fraction of HepG2 but not in AR42J cells by Western blot analysis using antibodies raised against FAEES, purified from rat liver microsomes or adipose tissue. Therefore, the enzyme responsible for the FAEE, FAME, or FAA synthesizing activities is most probably carboxylesterase in HepG2 cells and is structurally and functionally different than that present in AR42J cells. These studies also indicate the utility of HepG2 and AR42J cell cultures as an alternative to the animal model regarding studies on nonoxidative metabolism of alcohols and amines, in general.

Aniline Compounds↗
PubMed1999

Inadvertent ketamine overdose in children: clinical manifestations and outcome.

STUDY OBJECTIVE: We sought to characterize the clinical manifestations, outcome, and etiology of inadvertent ketamine overdose in the emergency department. METHODS: We investigated cases of inadvertent ketamine overdose in children seen in the ED solicited through electronic mail subscription lists or reported to the Institute for Safe Medication Practices. The clinical manifestations, outcome, and reported cause for each case are described. RESULTS: We identified 9 cases of inadvertent ketamine overdose in children treated in the ED. Patients received either 5(n=3), 10(n=5), or 100(n=1) times the intended dose, either by the intramuscular (n=5) or intravenous (n=4) route. All 9 experienced prolonged sedation (3 to 24 hours). Four experienced brief respiratory depression shortly after administration, and assisted ventilation was performed in 2. Two children without respiratory difficulty or hypoxemia were intubated by their physicians as a precaution. In 5 children, the dosing error was not discovered until late in the sedation, often when the child was not waking at the expected time. No adverse outcomes were noted, and all children were normal neurologically on discharge and longer-term follow-up if available. CONCLUSION: No adverse outcomes were noted in 9 healthy children treated in the ED who inadvertently received 5 to 100 times the intended dose of ketamine. Toxicity manifested as prolonged sedation in all 9 and brief respiratory depression in 4. The margin of safety in ketamine overdose may be wide, although less common and more serious outcomes cannot be excluded by this small, self-reported sample.

Anesthetics, Dissociative↗
PubMed1999

What is the optimal dose of intramuscular ketamine for pediatric sedation?

OBJECTIVE: The optimal dose of i.m. ketamine for ED procedural sedation in children is not known. The authors wished to quantify the dose-response of ketamine with respect to sedation adequacy, time to discharge, and adverse effects in order to identify an optimal dose. METHODS: The study was a consecutive case series of 1,022 children < or = 15 years of age given i.m. ketamine in the EDs of a university medical center and an affiliated county hospital over a nine-year period. Adequacy of sedation, time to discharge, and adverse effects were compared with dose administered. RESULTS: Doses in the sample averaged 3.96+/-0.69 mg/kg, with a range of 0.48 to 9.09 mg/kg. Children judged to be adequately sedated received higher doses compared with those inadequately sedated (3.94+/-0.44 mg/kg vs 3.77+/-0.49 mg/kg, p=0.041), and a nonsignificant trend was noted toward uniformly adequate sedation with increasing dose (< or =91% at <4.00 mg/kg, 93% at 4.00-4.49 mg/kg, and 100% at > or = 4.50 mg/kg). No significant difference or trend in time to discharge or adverse effects was noted between the children receiving <4.00 mg/kg and those receiving > or = 4.00 mg/kg of ketamine, and the study had power (alpha=0.05, beta=0.20) to detect a 9-minute difference in times to discharge, a 3.3% difference in rates of airway complications, a 5.6% difference in rates of emesis, and a 12.3% difference in rates of recovery agitation. CONCLUSION: Ketamine doses of 4 to 5 mg/kg i.m. produced adequate sedation in 93%-100% of children, suggesting that this dosing range may be optimal for ED procedural sedation. No difference in time to discharge or adverse effects was observed for lower or higher doses.

Anesthetics, Dissociative↗