Dexmedetomidine: Current Role in Burn ICU.

Dexmedetomidine (DEX) is a relativelyrecent a2-adrenergic agonist which provides sedation, anxiolysis and analgesia with much less respiratory depression than other sedatives. These characteristics have implemented the use of the drug in the ICUs in order to achieve the target of a "arousable sedation", thanks to its significant manageability. Its sedative-analgesic properties are also particularly suitable for use in burn ICUs, both adult and pediatric, which is why the current Guidelines have recognized a central role in the management of these categories of patients. Finally, DEX has showed significant anti-inflammatory effect both in animal models and in preliminary clinical trials, reducing vasopressor requirements and main mediators levels of the systemic inflammatory response involved in sepsis and similar processes, suggesting its use for improved outcome in ICU septic patients.

Photorefractive keratectomy and cataract.

Fifty male albino rabbits were studied. Ten animals served as controls. Forty animals were prepared to receive photorefractive keratectomy (PRK), including anesthesia, scraping of the corneal epithelial cells, etc. Twenty of these animals then received PRK with energy delivered by excimer laser (pulse rate = 20 Hz, fluence 250 mJ/cm2; number of pulses = 6032; cumulative UV dose = 1508J/cm2). The other 20 animals were exposed to the same operating microscope light as the PRK-treated animals, but they did not receive PRK. All three groups were divided into halves: the first half was immediately analyzed at 0 time, and the second half was observed 1 year later. Samples of aqueous humor and lens were analyzed. The levels of reduced and oxidized glutathione, hydrogen peroxide, ascorbic acid, and malondialdehyde were determined. Excimer laser-induced ultrastructural modifications of the lens, verified through scanning electron microscopy, were studied at the same intervals. Immediately after PRK, the biochemical parameters studied, both in aqueous humor and in lens of treated animals, showed significant differences. One year later, the observed biochemical variations in lens were still present, whereas aqueous humor values did not significantly differ from control values. Ultrastructural abnormalities of the lens appeared only 1 year after PRK In the animals that received only the preparation for PRK the biochemical and ultrastructural differences did not significantly vary as compared to the data obtained from control animals. These findings suggest that the biochemical and ultrastructural lens alterations induced by PRK may represent events relevant to cataractogenesis in the rabbit.

Effect of topical ketanserin administration on intraocular pressure.

The effect of topical ketanserin on intraocular pressure (IOP) in normotensive and hypertensive eyes was evaluated. The study was performed on 10 healthy volunteers and 10 glaucomatous patients. Systolic arterial blood pressure (SBP), diastolic arterial blood pressure (DBP), heart rate (HR), IOP, tonographic outflow facility, pupil diameter, corneal thickness, and tear secretion were recorded at baseline and at 1 hour intervals for 12 hours after topical administration of 0.5% ketanserin or placebo, given in a randomised, double masked, crossover fashion. The alternative treatment was given 1 week later. In all subjects ketanserin significantly lowered IOP, while no variations in SBP, DBP, HR, pupil diameter, corneal thickness, and tear secretion were found. When subjects received placebo no significant variations of IOP occurred. Total outflow facility, measured by conventional tonography, increased significantly after drug administration in all subjects. Ketanserin is effective up to 6 hours in control subjects and 9 hours in glaucomatous patients. The placebo did not induce any change in this component of the aqueous humour dynamic in normal or in glaucomatous eyes. The findings indicate that topical ketanserin might be added to the list of antiglaucomatous agents.

Effect of oral bromocriptine administration on intraocular pressure in normotensive and glaucomatous human subjects.

PURPOSE: The authors have verified the effect of orally administered bromocriptine on intraocular pressure in normotensive and glaucomatous human subjects. METHOD: Fifteen healthy volunteers and 15 glaucomatous patients were studied. Intraocular pressure, pupil diameter, total outflow facility, systolic arterial pressure, diastolic arterial pressure, and heart rate were recorded at baseline and at 1-h intervals for 12 h after oral administration of 2. 5 mg bromocriptine or placebo, given in a randomized, double-masked, cross-over fashion. The alternate regimen was given a week later. RESULTS: In all subjects bromocriptine significantly reduced intraocular pressure, whereas no variations in pupil diameter, systolic and diastolic arterial pressures, and heart rate were recorded. Moreover, total outflow facility, measured by conventional tonography, increased significantly both in normotensive and glaucomatous eyes. CONCLUSIONS: These findings indicate that oral bromocriptine administration could represent a new therapy to reduce intraocular pressure in humans.

Arf 193nm excimer laser corneal surgery and photo-oxidation stress in aqueous humor and lens of rabbit: one-month follow-up.

Twenty male albino rabbits were studied. Four animals served as controls; the remaining 16 animals represented the treated group. All the treated animals were exposed to the same amount of energy delivered by the excimer laser (pulse rate: 20 Hz, fluence 250mJ/cm2; number of pulses: 6032; cumulative UV dose 1508 J/cm2) and were divided into eight groups of 2 animals each (four eyes). Samples of aqueous humor and lens were obtained at the following intervals: 5, 10, 20 and 40 min and 1, 2, 3 and 4 weeks after photorefractive keratectomy (PRK). The levels of reduced and oxidized glutathione, hydrogen peroxide, ascorbic acid and malondialdehyde were determined. Aqueous humor analyses, twenty min after PRK, showed no significant differences with pre-treatment values, while the observed variations in lens were constantly present over the entire follow-up period (one month). These findings suggest that the biochemical lens alterations induced by PRK may represent the earliest events relevant to cataractogenesis in the rabbit.

[Systemic review of trials on the use of tramadol in the treatment of acute and chronic pain]. / Revisione sistematica dei trials sull'impiego del tramadolo nel trattamento del dolore acuto e cronico.

BACKGROUND: The purpose of the study was to verify the effectiveness of tramadol in the treatment of non-oncologic chronic pain, oncologic chronic pain and postoperative acute pain, applying the principles of meta-analytic analysis to randomized clinical trials (TCR). METHODS: I: Medline research of the TCR on the question in the period between 1989-1999, II: exclusion of single TCR through the question of Moore and Mcquay; calculation of the relative risk reduction (RRR), of the number needed to treat (NNT), of the odds ratio (OR) and of the typical odds ratio (TOR) of the trials which responded to characteristics of correct randomization and blindness, which expressed citation of the patients excluded from trial, and patients with measurable analgesic effectiveness (number of patients with reduction of the pain intensity 50%). RESULTS: 52 trials extracted from Medline: 10 on the treatment of non-oncologic chronic pain, 36 on the treatment of postoperative acute pain and 6 on the treatment of oncologic chronic pain. Responded fully to requirements: 8 studies (3 for non-oncologic chronic pain, 3 for postoperative acute pain and 2 for oncologic pain). The OR was 0.55 (-0.31/1.41); 0.44 (1.04/1.92) and 0.98 (0.5/1.46); the RRR was 0.26 (-0.19/0.71), 0.38 (0.15/0.61), 0.005 (0.19/0.20) and the NNT 6.6 (6.39/6.81), 5.26 (5.12/5.4), infinity in the 3 trials selected between those that concern the treatment of the nononcologic chronic pain (with TOR: 0.57 and confidence index: 0.23-0.9); the OR was 0.36 (1.06/1.78), 0.78 (-0.08/-1.64) and 1.12 (0.54/1.69); the RRR was 0.26 (-0.18/0.7), 0.07 (-0.2/0.35), -0.01 (-0.09/0.07) and the NNT 4.7 (4.42/4.58), 20 (19.8/20.20), infinity in the trials on the treatment of postoperative acute pain (with TOR: 0.4 and confidence index: -0.6-0.86); the OR was 0.53 (-0.67/1.73), 0.27 (-0.71/1.12); the RRR was 0.19 (-0.33/0.72), 0.35 (0.02/0.68) and the NNT 7.1 (6.78/7.42), 3.57 (3.37/3.76) in those that involved the treatment of oncologic chronic pain (with TOR: 0.49 and confidence index: 0.36-0.8). CONCLUSIONS: Although the short number of trials which can treated by the metanalytic technique the treatment with tramadol, compared comparison's to drugs (morphine, pentazocine, bupremorphine, etc.) determined a slight improvement in analgesic parameters or at least in analgesic effectiveness.

The Takagi Automatic Tangent Screen ATS-85 analyzer for the detection of glaucomatous patients.

The effectiveness of a new visual field analyzer, the Takagi Automatic Tangent Screen ATS-85, in detecting glaucomatous patients was studied. The study population consisted of three groups of subjects: normal healthy volunteers, glaucomatous patients with defective visual fields, and glaucomatous patients with early visual-field defects. Our results indicated that the screening program of the ATS-85 could be a useful instrument particularly for epidemiologic investigations.

Ocular findings in X-linked ichthyosis: a survey on 38 cases.

The authors report on the occurrence of ocular abnormalities in X-linked ichthyosis (XLI) patients, in their carrier mothers and in healthy volunteers who served as controls. The diagnosis of XLI was based on: (1) demonstration of steroid sulfatase deficiency in cultured skin fibroblasts; (2) lack of hybridization of patient's deoxyribonucleic acid (DNA) with specific steroid sulfatase complementary DNA probe; (3) electrophoretic mobility of plasma lipoproteins. Cholesterol sulfate plasma levels were also determined. The incidence of corneal opacities was the same in XLI patients and in their carrier mothers (23.7 and 24.3%, respectively). Neither other corneal nor ophthalmological alterations were found. Moreover, in XLI patients the plasma levels of cholesterol sulfate were about twenty times higher than in controls. Our findings demonstrate that ocular changes do not seem to be an absolute criterion for a definite diagnosis of XLI and the fact that the pathogenesis of corneal opacities is not due to an accumulation of cholesterol sulfate, but rather that this compound probably induces physicochemical changes of the corneal tissue properties.

Effect of oral ketanserin administration on intraocular pressure in glaucomatous patients.

We evaluated the effect of the antihypertensive drug ketanserin, a 5-HT antagonist, on intraocular pressure (IOP) in 20 patients with ocular hypertension. IOP, pupil diameter, systolic arterial pressure (SBP), diastolic arterial pressure (DBP) and heart rate (HR) were recorded at baseline and at 1-hr intervals for 3 hr after oral administration of 20 mg ketanserin or placebo, given in a randomized, double masked, cross-over fashion. The alternative treatment was given a week later. In all patients, ketanserin significantly lowered IOP and SBP, while no variations in pupil diameter, DBP and HR were found. Moreover, after drug administration, total outflow facility, measured by conventional tonography, increased significantly. These findings indicate that oral ketanserin could represent a new antiglaucomatous drug.

Anemia and chronic renal failure: a therapeutical approach by reduced glutathione parenteral administration.

Authors report on the effect of reduced glutathione parenterally administered on the anemic status in patients suffering from chronic renal failure and undergoing hemodialysis. Twenty patients were studied for 180 days and were divided into two age- and sex-matched groups. The first group (10 patients) received placebo, the second group (10 patients) received the treatment (1,200 mg of reduced glutathione). Reduced glutathione and placebo were given for 120 days in a randomized double-blind fashion and the following measurements were performed: red blood cells reduced and oxidized glutathione, plasma reduced and oxidized glutathione, hematocrit, hemoglobin, reticulocytes, serum iron, transferrin, indirect bilirubin, urea, creatinine, calcium, phosphate, parathyroid hormone and alkaline phosphatase. In the treated group, during the supplementation period, there was an increase in the levels of red blood cells and plasma reduced glutathione, hematocrit and hemoglobin and a concomitant decrease in plasma oxidized glutathione and reticulocytes with a maximum effect on the 120th day of therapy. In the placebo-treated group there were no significant variations of the parameters considered during the study period. When the therapy, on patients undergoing treatment, was terminated there was a drop in the analyzed parameters, which fell to pretreatment values at the subsequent controls. These findings seem to indicate that reduced glutathione could represent a useful drug in the treatment and management of anemia in patients affected by chronic renal failure.

In vivo measurement of human lens aging using the lens opacity meter.

Lens aging has been measured in vivo using a new instrument: the lens opacity meter 701 (Interzeag, Schlieren, Switzerland). Statistical analyses have been performed to verify the occurrence of the phenomenon, the sex differences and the reproducibility of the obtained results. The findings demonstrate an increase in the light scattering in the normal lens with aging, which is similar in both sexes. The instrument detects this process and the measurements have a high degree of reproducibility.

ArF 193 nm excimer laser corneal surgery as a possible risk factor in cataractogenesis.

It was evaluated whether ArF 193 nm excimer laser corneal surgery represents a risk factor in cataractogenesis. For this purpose, 20 male albino rabbits underwent a photorefractive keratectomy and biochemical analyses on aqueous humour (hydrogen peroxide, ascorbic acid, and reduced and oxidized glutathione) and on lens (malondialdehyde, reduced and oxidized glutathione) were performed. In the aqueous humour of all treated animals a significant increase in hydrogen peroxide and in oxidized glutathione and a concomitant decrease in ascorbic acid and reduced glutathione concentration were observed. Moreover, all these variations were significantly correlated with the cumulative UV dose used. In the lens, after excimer laser corneal surgery, there was a dramatic loss of reduced glutathione and a parallel increase in oxidized glutathione levels. Malondialdehyde concentration was also increased, but only at the highest UV exposure. Moreover, all these variations were significantly correlated with the cumulative UV dose used. These findings demonstrate that the exposure of aqueous humour and lens to the secondary radiation generated after ArF 193 nm excimer laser corneal photoablative keratectomy induces biochemical modifications which are known to be markers of cataractogenesis.