PubMed Health⌕ Search

Biomedical subjects

A Schlager

Publications and source records attributed to A Schlager.

At least 19 recordsLinked to original sources
PubMed2004

Modulatory effects on human sensorimotor cortex by whole-hand afferent electrical stimulation.

OBJECTIVE: To investigate the effect of electrical stimulation of the nerve afferents of the hand on cortical activity elicited by whole-hand subthreshold stimulation for sensation in healthy human subjects. METHODS: Ten healthy volunteers were studied using BOLD-fMRI with 1) a test motor-task with finger-to-thumb tapping of the left hand, 2) a whole-hand afferent electrical stimulation of the left hand below the sensory level for sensation for 30 minutes, 3) a second fMRI run with the same paradigm as in the test motor-task immediately after electrical stimulation, and 4) a final identical fMRI run 2 hours post-stimulation to test the cortical changes induced by electrical stimulation. Experiments were carried out on a 1.5 T MR scanner and for fMRI echoplanar sequences were used. Data analysis was performed with SPM99. RESULTS: An increase of movement-related responses was seen within the primary motor and primary somatosensory areas of both hemispheres when comparing the test motor-task with the motor-task after electrical stimulation relative to the baseline or sham stimulation. Two hours post-stimulation the modulatory effects of mesh-glove stimulation diminished to baseline level except within the contralateral primary motor region. CONCLUSIONS: The increased BOLD response spatially localized within the sensorimotor cortex reflects an increase in neuronal activity that may provide augmented neuronal excitability.

Adult↗
PubMed2004

Neuropathic pain after femoropopliteal bypass surgery.

OBJECTIVE: This retrospective study was performed to investigate prolonged postoperative pain in the area of the proximal or distal scar or the bypass tunnel after femoropopliteal bypass surgery to treat symptomatic peripheral arterial disease. PATIENTS AND METHODS: Ninety-three patients with peripheral arterial disease who underwent femoropopliteal bypass surgery between January 2000 and December 2002 were included in the study. The short-form McGill Pain Questionnaire was used to score pain. Ultrasound examination of the soft tissue around the graft was performed to exclude other pathologic conditions responsible for pain, such as inflammatory processes, perigraft reactions, swollen lymph nodes, and hematomas. RESULTS: Pain in at least one scar existed in 22 patients on average 13.9 +/- 9.8 months after surgery. In 10 patients pain existed simultaneously along the inguinal scar and the above-knee or below-knee scar. Pain along the bypass tunnel was experienced by seven patients. Most patients had mild to moderate pain. The mean numeric ranking score of pain severity in patients with pain was 4.2 +/- 2.3. The occurrence of prolonged postoperative pain was not associated with age, gender, diabetes, indication for surgery, material or type of bypass, number of preceding operations, or postoperative wound complications. Only follow-up time after femoropopliteal bypass surgery tended to be lower in patients with pain compared with those without pain. CONCLUSION: Prolonged postoperative neuropathic pain along the distal and proximal incision or the bypass tunnel exists in one fourth of patients after femoropopliteal bypass surgery. Patients should be informed of this kind of complication before surgery. The results of our study justify further investigations of the origin and treatment of this pain, to find effective methods to reduce the incidence of prolonged postoperative pain after femoropopliteal bypass surgery.

Aged↗
PubMed2001

Prospective randomized trial using laser acupuncture versus desmopressin in the treatment of nocturnal enuresis.

OBJECTIVES: Several treatment modalities for children suffering from monosymptomatic nocturnal enuresis are available, but desmopressin is a well-established option. On the other hand, alternative nonpharmacological therapies such as laser acupuncture are more frequently requested by the parents. To our knowledge, there is no prospective randomized trial which evaluated the efficacy of such an alternative approach in comparison with the widespread use of desmopressin. METHODS: Forty children aged over 5 years presenting with primary nocturnal enuresis underwent a previous evaluation of their voiding function to assure normal voiding patterns and a high nighttime urine production. Then the children were randomized into two groups: group A children were treated with desmopressin alone, and group B children underwent laser acupuncture. All children were investigated after a minimum follow-up period of 6 month to evaluate the duration of the response. RESULTS: The children of both groups had an initial mean frequency of 5.5 wet nights per week. After a minimum follow-up period of 6 months reevaluation revealed a complete success rate of 75% in the desmopressin-treated group. Additional 10% of the children had a reduction of their wet nights of more than 50%. On the other hand, 6 months after laser acupuncture, 65% of the randomized children were completely dry. Another 10% had a reduction of the enuresis frequency of more than 50% per week. 20% of the children in the desmopressin-treated group did not respond at all as compared with 15% in the acupuncture-treated group. Statistical evaluation revealed no significant differences among the response rates in both groups. CONCLUSION: Im comparison with pharmacological therapy using desmopressin, our study shows that laser acupuncture should be taken into account as an alternative, noninvasive, painless, cost-effective, and short-term therapy for children with primary nocturnal enuresis in case of a normal bladder function and high nighttime urine production. Success rates indicated no statistically significant differences between the well-established desmopressin therapy and the alternative laser acupuncture.

Acupuncture Therapy↗
PubMed2000

Low-power laser light in the healing of burns: a comparison between two different wavelengths (635 nm and 690 nm) and a placebo group.

BACKGROUND AND OBJECTIVE: Studies on the influence of low-power laser light on wound healing have shown inconsistent results, or, as in the case of burns, are very scarce. We have studied the effects of two different low-power diode laser lights on the healing of burns in rats. STUDY DESIGN/MATERIALS AND METHODS: Thirty rats were burned on both flanks and randomly allocated to one of three study groups. In group A, both wounds remained untreated; in groups B and C, one wound each was irradiated with 635 nm or 690 nm laser light (1.5 J/cm(2)), whereas the other wound remained untreated. Diameter, redness, and edema of the wounds were examined daily. RESULTS: Between and within groups, diameter, redness, and edema of the wounds were similar throughout the entire observation period. Irradiation of the burns did not accelerate wound healing when compared with control wounds. CONCLUSION: We conclude that neither 690 nm nor 635 nm low-power laser light produced any beneficial effects on the healing processes of burns in rats.

Analysis of Variance↗
PubMed2000

Exogenous neopterin causes cardiac contractile dysfunction in the isolated perfused rat heart.

Neopterin is known in humans as a sensitive marker for diseases associated with increased activity of the cellular immune system. Recent studies report neopterin also to exhibit distinct effects: neopterin induces inducible nitric oxide synthase expression in rat vascular smooth muscle cells and activates translocation of nuclear factor- kappa B. Neopterin may also induce oxidative stress causing apoptotic cell death, or superinduce tumor necrosis factor- alpha -mediated apoptosis. Observing these effects in cell cultures, we were interested in possible consequences of neopterin on cardiac function in the isolated perfused rat heart. The influence of neopterin in three different concentrations (10 micromol/l, 50 micromol/l, 100 micromol/l) on cardiac contractility parameters and coronary vascular resistance were studied in 67 male Sprague-Dawley rats using the temperature-controlled and pressure-constant Langendorff apparatus with retrograde perfusion of the aorta with a Krebs-Henseleit buffer. Treatment with 100 micromol/l neopterin resulted in a significant decrease in coronary flow and cardiac contractility. Coronary flow decreased from 15.2 to 9.5 ml/min (P=0.002), left ventricular pressure from 80 to 52 mmHg (P=0. 002), rate of pressure fall from 1605 to 923 mmHg/s (P=0.001) and rate of pressure rise from 2862 to 1709 mmHg/s (P=0.001). Concentrations lower than 100 micromol/l neopterin had no significant effect on cardiac function. Our study demonstrates a considerable influence of exogenous neopterin on cardiac performance in the Langendorff model of isolated perfused rat hearts. This has to be considered a potential pathogenic factor of cardiac disturbances in diseases in which high concentrations of neopterin are released due to immune activation. At present the exact mechanism remains unclear.

Animals↗
PubMed2000

Korean hand acupressure reduces postoperative vomiting in children after strabismus surgery.

A double-blind, randomized, placebo-controlled study was conducted to investigate the effectiveness of Korean hand acupuncture in preventing postoperative vomiting in children scheduled for strabismus surgery. In one group, acupressure was performed 30 min before induction of anaesthesia by applying an acupressure disc onto the Korean hand acupuncture point K-K9; the disc remained in situ for at least 24 h. The second group functioned as placebo group. The treatment groups did not differ with regard to patient characteristics, surgical procedure and anaesthetic administered. In the acupressure group, the incidence of vomiting was significantly lower (20%) than in the placebo group (68%). We conclude that Korean hand acupressure of the acupuncture point K-K9 is an effective method for reducing postoperative vomiting in children after strabismus repair.

Acupressure↗
PubMed2000

Rectally administered dimenhydrinate reduces postoperative vomiting in children after strabismus surgery.

We have investigated the effectiveness of rectally administered dimenhydrinate on postoperative vomiting in children undergoing strabismus surgery, in a double-blind, randomized, placebo-controlled study. In one group, dimenhydrinate 50 mg was administered rectally 30 min before starting anaesthesia, whereas in the control group, placebo suppositories were given. Children who received dimenhydrinate showed a significantly (P < 0.001) lower incidence of vomiting (15%) than those in the control group (75%). We conclude that rectal administration of dimenhydrinate is an effective means of reducing postoperative vomiting in children undergoing strabismus surgery.

Administration, Rectal↗
PubMed2000

Healing of burns after treatment with 670-nanometer low-power laser light.

Recent investigations have reported contradictory results on the influence of low-power laser light on wound healing. Low-power laser with a power output of 250 mW and an emitted laser light of 670 nm have been insufficiently investigated to date. The effect of a 250-mW/670-nm laser light on the healing of burning wounds in rats was investigated. Thirty rats were burned on both flanks. One wound was irradiated with 670-nm laser light (2 J/cm2), whereas the other side remained untreated. Macroscopic evaluation of the wounds was performed daily; 10, 20, and 30 days after burning, 10 rats were killed and the wounds histologically evaluated. Neither macroscopic nor histologic examination of the irradiated wound showed accelerated wound healing when compared with control wounds. In the present study, irradiation of burns with a 250-mW/670-nm laser light produced no beneficial effects on wound-healing processes.

Animals↗
PubMed2000

Oxygen application by a nasal probe prevents hypoxia but not rebreathing of carbon dioxide in patients undergoing eye surgery under local anaesthesia.

BACKGROUND/AIM: Hypoxia and carbon dioxide rebreathing are potential problems during eye surgery in spontaneously breathing patients. The aim of the present study was to determine effectiveness of nasal application of oxygen to prevent hypoxia and carbon dioxide accumulation in spontaneously breathing patients undergoing cataract surgery. METHODS: Oxygenation and carbon dioxide rebreathing were examined in 40 elderly patients using two different methods of oxygen supply-nasal v ambient air-with a constant flow of 2 l/min. Partial pressure of carbon dioxide under ophthalmic drapes, transcutaneous pressure of carbon dioxide, and the respiratory rate were measured during 25 minutes while oxygen was supplied via a nasal cannula or into the ambient air under the drapes. RESULTS: In both groups carbon dioxide accumulation under the drapes, carbon dioxide rebreathing, tachypnoea, and an increase in peripheral oxygen saturation occurred. No significant differences were found between the two methods. CONCLUSION: Nasal application of oxygen prevented hypoxia but did not prevent carbon dioxide accumulation in patients undergoing eye surgery under retrobulbar anaesthesia. Additionally, as a side effect when using nasal probes, irritation of the nose was described in half of the patients investigated.

Aged↗
PubMed1999

New support for ophthalmic drapes.

A new flexible support for ophthalmic drapes with the possibility of continuous oxygen supplementation was designed for use in patients undergoing eye surgery under local anesthesia. This new equipment is easy to handle and prevents contact between the patient's face and the ophthalmic drape. To prevent hypoxia of spontaneously breathing patients, the ambient air under the drapes can be supplemented with oxygen using this new equipment and no other devices. The equipment described here is advantageous for practical use in patients undergoing eye surgery under retrobulbar anesthesia.

Anesthesia, Local↗
PubMed1999

Heat trapped under paper and plastic ophthalmic drapes during eye surgery using local anesthesia.

PURPOSE: To assess whether heat trapped under ophthalmic drapes is responsible for patient reports of being hot during cataract surgery using local anesthesia. SETTING: Departments of Anaesthesia and Intensive Care Medicine and of Ophthalmology and Optometry, Innsbruck University Hospital, Innsbruck, Austria. METHODS: In a prospective, randomized, single-blind study, the temperature in the ambient air under 2 types of paper drapes (Group A: Barrier Ophthalmology Drape, Johnson & Johnson; Group B: Steri Drape 1062, 3M) and a plastic drape (Group C: cotton drape + Steri Drape 1024, 3M) was measured for 25 minutes in 60 patients having cataract surgery under local anesthesia. RESULTS: Three minutes after the patient's head was draped, the mean temperature under the drape began to increase significantly: Group A, 25.7 degrees C +/- 0.3 degree C (SD) to 29.17 degrees C +/- 0.9 degree C (P < or = .001); Group B, 25.87 degrees C +/- 0.4 degree C to 29.41 degrees C +/- 0.9 degree C (P < or = .001); Group C, 25.8 degrees C +/- 0.35 degree C to 29.4 degrees C +/- 0.6 degree C (P < or = .001). It continued to increase in all groups as the operation continued. No significant differences in temperature were observed among the 3 drape types studied. Subjective thermal discomfort was reported by 35% to 40% of patients. CONCLUSION: Paper drapes did not cause less heat from being trapped than the plastic drape. Trapped heat may impair the comfort of patients having eye surgery under local anesthesia.

Anesthesia, Local↗
PubMed1999

Accumulation of carbon dioxide under ophthalmic drapes during eye surgery: a comparison of three different drapes.

Carbon dioxide accumulation under ophthalmic drapes is caused by their impaired permeability to exhaled carbon dioxide in spontaneously breathing patients. Three different ophthalmic drapes were examined under clinical conditions. Sixty unpremedicated patients of each gender, aged over 60 years and with an ASA status of I-III undergoing cataract surgery under retrobulbar anaesthesia were included in the study. Patients with known pulmonary diseases were excluded. The patients were divided into three groups of 20 patients each. In all groups, oxygen was insufflated under the drapes at a constant flow of 21.min-1. Carbon dioxide concentration in the inspired air, transcutaneous carbon dioxide pressures, respiratory rate and oxygen saturation by pulse oximetry were measured. Accumulation of carbon dioxide under the drapes, increase of partial pressure of transcutaneous carbon dioxide and hyperventilation were observed in all three groups. An oxygen supply of 21.min-1 prevented hypoxaemia but not hypercapnia. Therefore, producers of ophthalmic drapes are encouraged to look for further ways to increase the carbon dioxide permeability of their drapes with the aim of reducing carbon dioxide accumulation and hyperventilation in spontaneously breathing patients undergoing eye surgery.

Aged↗
PubMed1999

Effect of fluvoxamine on sufentanil antinociception and tolerance under chronic intravenous infusion in rats.

Fluvoxamine, a selective serotonin reuptake inhibitor (SSRI), significantly potentiates analgesia when administered in animals together with opioids. The aim of the present study was to investigate the effects of fluvoxamine on sufentanil antinociception and tolerance. Following animal care committee approval, the effects of continuous infusions of fluvoxamine and sufentanil were studied in behavioural tests (hot-plate test, tail-flick test, catalepsy test) in Sprague-Dawley rats with a jugular vein catheter. Saline was administered as a control. The time-effect curves for continuous intravenous sufentanil indicate dose-related antinociception and rapid development of tolerance in the hot-plate and tail-flick tests. Co-administration of fluvoxamine with continuous sufentanil enhances antinociception and attenuates development of tolerance, most clearly seen in the tail-flick test. Fluvoxamine alone and saline were not effective. No animal showed catalepsy. As a side effect we observed a marked loss of body weight. The IC50 values of sufentanil binding with and without fluvoxamine addition are 0.56+/-0.17 nM and 0.3+/-0.15 nM, respectively, indicating no direct effect on the occupancy of sufentanil on the mu-receptor by this serotonin reuptake inhibitor. In conclusion, we were able to show that the combination of an opioid with an SSRI at low doses improves analgesia and decreases development of tolerance in nociceptive tests in rats. The clinical implications of these promising results in an animal model, however, await further investigation.

Analgesics, Opioid↗
PubMed1999

New equipment to prevent carbon dioxide rebreathing during eye surgery under retrobulbar anaesthesia.

BACKGROUND: Carbon dioxide concentration under ophthalmic drapes increases during eye surgery under local anaesthesia. A new prototype has been designed which combines continuous suction of carbon dioxide enriched air and continuous oxygen insufflation under ophthalmic drapes to prevent carbon dioxide accumulation in spontaneously breathing patients undergoing cataract surgery. METHODS: In a prospective randomised single blind study the effectiveness of this new prototype was examined in 50 unpremedicated elderly patients. In 25 patients suction was applied under ophthalmic drapes, whereas in the other 25 patients no suction was used. In all cases oxygen was insufflated under the drapes at a constant flow of 2 l/min. Carbon dioxide concentration in the ambient air surrounding the patient's head under ophthalmic drapes, transcutaneous partial pressure of carbon dioxide, respiratory rate, and oxygen saturation were measured. RESULTS: Carbon dioxide concentration under the drapes, transcutaneous partial pressure of carbon dioxide, and respiratory rate remained unchanged in the suction group, whereas in the non-suction group these values increased significantly. Oxygen saturation rose significantly in both groups without differences between the groups. CONCLUSION: Application of this new prototype for continuous aspiration of carbon dioxide enriched air prevents carbon dioxide rebreathing and subsequent hypercapnia associated with an elevated respiratory rate. This new equipment may therefore be useful in patients undergoing ophthalmic surgery under retrobulbar anaesthesia.

Aged↗
PubMed1998

Transcutaneous CO2/O2 and CO2/air suction in patients undergoing cataract surgery with retrobulbar anaesthesia.

We investigated transcutaneous partial CO2 and O2 pressures and respiratory rate in unpremedicated elderly patients of ASA physical status 1 to 3 who underwent cataract surgery under retrobulbar anaesthesia. In group A no air suction was used. In group B suction was applied under the sterile drapes to avoid rebreathing of CO2. In group A transcutaneous partial CO2 pressure and respiratory rate significantly increased compared with baseline, whereas in group B they remained constant. In both groups transcutaneous partial O2 pressure and oxygen saturation as measured by pulse oximetry significantly rose after insufflating oxygen 31.min-1. Heart rate and mean arterial blood pressure remained constant. Our results demonstrate that the application of suction near the patient's head prevents CO2 rebreathing and subsequent hypercapnia associated with an elevated respiratory rate. The use of suction makes it unnecessary to raise oxygen administration. Suction combined with monitoring of partial CO2 pressure using transcutaneous sensors should be used in all ophthalmological operations under retrobulbar anaesthesia.

Aged↗
PubMed1998

Laser stimulation of acupuncture point P6 reduces postoperative vomiting in children undergoing strabismus surgery.

We conducted a double-blind, randomized, placebo-controlled study to investigate the effectiveness of P6 acupuncture on postoperative vomiting in children undergoing strabismus surgery. Acupuncture was performed by laser stimulation with a low-level laser. Laser stimulation of P6 was administered 15 min before induction of anaesthesia and 15 min after arriving in the recovery room. In the laser stimulation group, the incidence of vomiting was significantly lower (25%) than that in the placebo group (85%).

Acupuncture Points↗