Effects of dexmedetomidine on propofol and remifentanil infusion rates during total intravenous anesthesia for spine surgery in adolescents

Introduction: Total intravenous anesthesia with propofol and a synthetic opioid is a frequently chosen anesthetic technique for posterior spinal fusion. Despite its utility, adverse effects may occur with high or prolonged propofol dosing regimens including delayed awakening. The current study investigated the propofol‐sparing effects of the concomitant administration of the α₂‐adrenergic agonist, dexmedetomidine, during spinal fusion surgery in adolescents. Methods: The surgical database of the department of orthopedic surgery was searched and patients (12–21 years of age) were identified who had undergone spinal fusion for either idiopathic or neuromuscular scoliosis during the past 24 months. Patients were assigned to two groups. Group 1 included patients anesthetized with propofol and remifentanil and group 2 included patients anesthetized with dexmedetomidine, propofol, and remifentanil. In the latter group, dexmedetomidine was administered as a continuous infusion of 0.5 μg·kg^?1·h^?1 started after the induction of anesthesia without a loading dose. Propofol was adjusted to maintain the bispectral index (BIS) number at 40–50 and remifentanil was adjusted to maintain the mean arterial pressure (MAP) at 50–65 mmHg. Labetolol or hydralazine was used if the MAP could not be maintained at 50–65 mmHg with remifentanil up to a maximum dose of 0.6 μg/kg/min. Statistical analysis included a nonpaired t‐test for parametric data (age, weight, remifentanil/propofol infusion requirements, and heart rate/blood pressure values). A nonparametric statistical analysis (Dunn) was used to compare BIS numbers. Parametric data are presented as the mean ± sd while nonparametric data are presented as the median and the 95th percentile confidence intervals. Results: Twelve patients received propofol–remifentanil–dexmedetomidine and 24 received propofol–remifentanil. There were no differences in the demographic data, BIS numbers or hemodynamic parameters between the two groups. There was a reduction in the propofol infusion requirements in patients who also received dexmedetomidine (71 ± 11 μg·kg^?1·min^?1) compared with those receiving only propofol–remifentanil (101 ± 33 μg·kg^?1·min^?1, P = 0.0045). No difference was noted in the remifentanil infusion requirements or the use of supplemental agents (hydralazine and labetolol) to maintain controlled hypotension. Conclusion: The concomitant use of dexmedetomidine in patients undergoing spinal fusion reduces propofol infusion requirements when compared with those patients receiving only propofol and remifentanil.     

A CCl4/CHCl3 Interaction Study in Isolated Hepatocytes: Selection of a Vehicle

Emulphor, ethanol, and dimethyl sulfoxide (DMSO) were evaluatedas vehicles in studying the toxicity of CCl₄ and CHCl₃ in isolatedhepatocytes. The appropriateness of the vehicle was determinedby evaluating the following parameters: solubility of CCl₄ andCHCl₃ in the vehicle, cell injury (intracellular K+), cell death(LDH leakage), and lack of interaction (protection or enhancedtoxicity) with CCl₄. and CHCl₃. The relative toxicity of thevehicles according to maximum no effect levels (v/v) was: emulphor(0.125%) > ethanol (1.0%) > DMSO (5.0%). Emulphor at toxiclevels was inadequate to dissolve enough CCl₄ to evaluate inthis system. Ethanol (5.0, 2.5, 1.0, 0.5%) was more toxic thanDMSO and interacted with both CCl₄. and CHCl₃ to enhance toxicity.DMSO (15.0, 5.0, 2.5%) did not significantly alter the toxicityof CCl₄. and CHCl₃ no interaction. These data suggest that DMSOshould be the vehicle for evaluating the toxicity of CCl₄. andCHCl₃ and their mechanisms of action in the isolated hepatocyte.     

Primary infertility in women exposed to diethylstilboestrol in utero

Summary. In a selected group of 40 women who had been exposed to diethylstilboestrol in utero , 18 conceived without difficulty and 22 had primary infertility. Among those with primary infertility there was a significantly higher rate of anatomical structural defects and a greater tendency for menstrual disorders than in those without infertility. Thirteen (59%) of the women with primary infertility conceived, most after treatment with ovulation stimulating drugs. Spontaneous abortion and tuba1 pregnancy were frequent (47% and 10% respectively) and similar in both fertility groups. Of 13 infertile women examined, 4 (31%) had mild hyperprolactinemia—a hithero unreported finding for such women.     

Pediatric dentistry and the child with asthma

A child with asthma who needs dental treatment, can be a source of concern to the pediatric dentist. Recent studies have provided a better understanding of the pathophysiology of asthma as well as the role of emotions in the expression of asthma. The goal in managing the patient with asthma is to prevent an acute asthmatic episode during the dental procedure. Suggestions are made to meet this goal. Asthma does not require alteration of routine dental practices and, most importantly, the well-managed child with asthma does not need special treatment when it comes to possible behavior problems in the dental office.     

Screening for breast cancer in Catalonia: Which policy is to be preferred?

Background: the effects and costs of different policies forbreast cancer screening in Catalonia (Spain) were analysed,to give a basis for setting priorities and deciding on the introductionof a screening programme. Methods: the MISCAN (MIcrosimulationSCreening ANalysis) model of the natural history of breast cancerwas used. The epidemiology of breast cancer in Catalonia andthe demography of the Catalan population was taken into accountas well as the results on mortality reduction from a Swedishoverview of breast cancer screening trials. Results: the reductionin breast cancer mortality in the total female population dueto a screening programme for the age group 50–64 yearswould be 16, 12 and 9%, with screening intervals of one, twoand three years respectively. The cost-effectiveness ratios(CE ratios) for these scenarios were 924,000, 730,000 and 719,000pesetas (P_t) per life-year gained respectively (5% discounting).The most cost-effective screening scenario is the one in whichwomen aged 50–69 years are screened with an interval ofthree years with a mortality reduction of approximately 12%in the total female population (CE ratio = 694,000 P_t). Screeninguntil the age of 69 years (two year interval) was almost ascost-effective as screening the age group 50–64 yearswith a two year interval, with a reduction in breast cancermortality of 15%. Extension to under the age of 50 years resultedin diverging results depending on the assumptions for improvementin prognosis for younger women (40–49 years). Conclusion:if the extension of a two yearly screening programme for womenaged 50–64 years is considered (mortality reduction of12%), extension to older women would be more advisable, basedon proven benefits and costs, than extension to younger agegroups.     

Efficacy of Low-Level Laser Therapy for Chronic Cutaneous Ulceration in Humans: A Review and Discussion

Chronic wounds, particularly venous ulcerations, are notoriously difficult to heal. Because current therapies are variable in their ability to induce complete healing, there remains a need to develop adjunctive treatments that can improve or accelerate the healing process. The use of low-energy lasers to stimulate wound healing has been pursued over many decades in studies of varying quality. This form of treatment has had high appeal due to its novelty, relative ease, and low morbidity profile. The authors reviewed the available published literature on low-level laser technology in an attempt to provide cumulative insight on the effect of this treatment for wound healing.     

Ossifying Fibroma of Long Bone — Report of Two Cases

Two cases of ossifying fibroma of long bone with long term follow-up are described. Although the diagnosis can usually be established from the plain radiographs, computerised tomography can be of considerable value. Because of therapeutic implications it is important to distinguish this lesion from other fibro-osseous lesions of bone.