Search PubMed⌕ Search

Biomedical subjects

H Manninen

Publications and source records attributed to H Manninen.

At least 55 records · Page 3Linked to original sources
PubMed1992

Does the anesthetic method influence the postoperative breathing pattern and gas exchange in hip surgery? A comparison between general and spinal anesthesia.

We studied the effects of elective hip surgery, performed under either spinal (SA, n = 10) or general anesthesia (GA, n = 10), on breathing pattern and gas exchange. Measurements were made with respiratory inductive plethysmograph and indirect calorimetry in two positions before and after surgery. The method of anesthesia had no effect on the severity of postoperative hypoxemia. Reduced arterial oxygenation (PaO2; P less than 0.001, SA from 12.5 +/- 2.37 kPa to 10.5 +/- 1.38 kPa, GA from 12.5 +/- 2.95 kPa to 10.5 +/- 1.75 kPa) despite increased alveolar ventilation (P less than 0.01; from 2.30 +/- 0.37 l/min to 2.39 +/- 0.43 l/min in SA, 2.27 +/- 0.56 l/min to 2.57 +/- 0.35 l/min in GA) and reduced arterial carbon dioxide partial pressure (PaCO2; SA from 5.20 +/- 0.22 kPa to 4.95 +/- 0.33 kPa, P less than 0.01, GA from 5.07 +/- 0.36 kPa to 4.72 +/- 0.41 kPa, P less than 0.05) indicated maldistribution of ventilation and perfusion. Changes in breathing pattern and gas exchange and differences between the groups were minimal. Minute ventilation, tidal volume and mean inspiratory flow remained unchanged in both groups. The contribution of rib cage to tidal volume increased postoperatively in the supine position (P less than 0.001; SA from 32.6% +/- 10.3 to 46.3% +/- 7.5, GA from 36.5 +/- 16.4 to 48.5% +/- 15.4). CO2 production, oxygen consumption and energy expenditure remained unchanged. The postoperative changes in breathing pattern are related to the operation, not to the type of anesthesia and do not explain the alterations in gas exchange.

Adult↗
PubMed1992

Cervical rotation lateral flexion test in brachialgia.

The cervical rotation lateral flexion test (CRLF test), developed earlier, was used to examine patients with brachialgia and thoracic outlet syndrome (TOS) symptoms to detect possible restriction of the movement of the first rib. The test was performed for 23 patients, five of them both before and after treatment. The patients were assessed independently by two clinicians to analyze the interobserver reliability. A cineradiographic examination was performed so that any restriction of the movement of the first rib during expiration and inspiration could be detected objectively. The interobserver repeatability of the test was excellent, thus making the cineradiographic examination unnecessary. It is recommended that this test be included in the clinical investigation of all patients with brachialgia with or without radicular pain.

Adult↗
PubMed1991

Respiratory changes after open-heart surgery.

Breathing pattern was studied non-invasively in 20 coronary artery bypass surgery patients before the operation and post-operatively after weaning from mechanical ventilation. Post-operatively minute ventilation (VE), breathing frequency (Fr) and mean inspiratory flow (VT/TI) increased (28%, 42%, 27%; p less than 0.01, p less than 0.001, p less than 0.01, respectively), while tidal volume (VT) decreased (15%, p less than 0.025). CO2 production (VCO2) and oxygen consumption (VO2) increased postoperatively (p less than 0.001 for both), contributing to the increase in ventilatory demand. Reduced variation of VT and Fr (p less than 0.001, p less than 0.01, respectively) and number of sighs (p less than 0.001) were characteristic of the post-operative breathing pattern. Post-operatively an increase in the contribution of rib cage (%RC) to tidal volume in the supine position was observed suggesting reduced motion of the diaphragm. All patients had atelectasis, 17 had pleural fluid and only 6 normal vascularity post-operatively. The shallow breathing in combination with increased ventilatory demand, impaired gas exchange and the surgical trauma of the thorax predispose to postoperative respiratory complications.

Coronary Artery Bypass↗
PubMed1991

CO2 gas perfusion: improved efficiency and safety with sapphire-probe laser ablation of human artery.

CO2 gas has been proposed as a new perfusion medium for laser angioplasty. To compare CO2 gas with conventional saline perfusion, 146 fresh specimens of normal and atheromatous human artery were irradiated with a neodymium: yttrium-aluminum-garnet laser with a sapphire probe in flowing whole blood in an experimental circulation-occlusion model. The dimensions of the ablation crater and the extent of the surrounding tissue damage were measured microscopically. Significantly better ablation of atheromatous plaque was achieved with CO2 perfusion than with saline perfusion: mean ablation areas were 5.0 mm2 versus 2.8 mm2, respectively (P = .001, Student t test). In contrast, the ablation areas on normal vessel wall were identical (mean, 3.4 mm2) with the two perfusion media. Moreover, CO2 gas functioned as a negative contrast agent and facilitated direct monitoring of the laser recanalization procedure. On an experimental basis, CO2 gas perfusion seems to improve the efficiency and safety of laser ablation in human arteries.

Aged↗
PubMed1991

Evaluation of heart size and pulmonary vasculature. Conventional chest roentgenography and image intensifier photofluorography compared.

Inter- and intraobserver variation and diagnostic accuracy in estimation of heart size and pulmonary vasculature were evaluated for conventional film-screen technique and image intensifier photofluorography. Interpretation of 218 p.a. and lateral chest films by both imaging techniques was performed independently by 4 readers. Heart size relative to body surface area measured from the plain chest films was used as the reference in cardiac size determination. Overall diagnostic accuracies of conventional radiography and image intensifier photofluorography for cardiomegaly were close to each other, 0.70 vs 0.68, respectively. Specificity of film-screen radiography was better than that of photofluorography (0.92 vs 0.84, p less than 0.05). Interobserver agreement was poor both in assessment of the heart size and pulmonary vasculature (range of kappa coefficients 0.18-0.59) while the intraobserver consistency (kappa coefficients 0.60-0.85) was good to excellent. The results suggest a limited usefulness of visual assessment of heart size and pulmonary vasculature in chest roentgenographs.

Aged↗
PubMed1991

Laser ablation ability of different fiber tips on human arteries. The role of photothermal effect.

To compare laser ablation abilities of bare tip and metal probe as well as spectraprobe, specimens from human normal and atherosclerotic aorta were irradiated with Nd-YAG laser. To evaluate the influence of photothermal effect thermal energy productions of 3 tips were measured with a calorimeter. The results showed that the bare tip produced the most effective ablation in arterial atheroma, followed by the metal probe and the spectraprobe. Similarly, the ratio of the ablation area on atheroma to that on normal vessel was the best with the bare tip and the worst with the spectraprobe. However, the extent of surrounding tissue damage adjacent to the ablation crater was the largest with the bare tip and the smallest with the spectraprobe. These differences cannot be explained only by variations in the photothermal effect, since thermal energy production is proved to be almost equal among the 3 laser fiber tips.

Aged↗
PubMed1990

Carbon dioxide gas as a perfusion medium for the sapphire probe in laser ablation of human atheromatous plaques: comparison study with saline.

The effectiveness of CO2 gas as a perfusion medium was compared to that of saline in laser ablation of human atheromatous plaque. In an experimental circulation-occlusion model using flowing whole blood, human cadaveric arterial samples were irradiated by a sapphire probe with the Nd-YAG laser. The following experiments were performed: 1) lasing without perfusion, 2) lasing with saline perfusion of the probe, and 3) lasing with CO2 perfusion. Different perfusion flow rates of saline and CO2 were used. Results showed that the mean ablation area was 1.6-fold larger with CO2 than with saline perfusion (P less than 0.05, Student's t test). The mean lateral injury at the site adjacent to the ablation crater and at the area directly facing the probe was not significantly different with either perfusion medium. The larger ablation area with CO2 was probably due to the fact that CO2 is a good insulator for maintaining a higher probe temperature and keeps the probe free of blood debris. In conclusion, our results show that CO2 perfusion facilitates more effective laser ablation of atheromatous plaque than saline perfusion by the sapphire probe with the continuous wave Nd-YAG laser.

Aged↗
PubMed1990

Percutaneous transluminal laser angioplasty. Progress over the past two years.

The progress in percutaneous transluminal laser angioplasty (PTLA) over the past two years is presented. The technical development includes the application of new equipments to laser sources, delivery systems and monitors. We review new experimental research in rapidly establishing animal models and human postmortem specimens, as well as efforts to select adequate wave length and irradiation time for laser energy with suitable infusion media. A summary of clinical trials is given on expanding usage, complication rates and long-term patency of PTLA. The current trends in PTLA respecting guide wire assisted balloon angioplasty and other recanalization methods are described.

Angioplasty, Balloon↗
PubMed1989

Cineradiography of the hypomobile first rib.

A patient with bilateral chronic brachialgia was cineradiographically shown to have hypomobile first ribs bilaterally. This finding can be elicited by the Expiration-Inspiration (E-I) test, in which the patient is palpated just beneath the clavicles while breathing. Right side scalenus muscle activation restored the movement of the right first rib. The cineradiography confirms the validity of the palpatory E-I test which has been previously described.

Cineradiography↗
PubMed1988

Reduction of radiation dose and imaging costs in scoliosis radiography. Application of large-screen image intensifier photofluorography.

Photofluorography using a large-field image intensifier (Siemens Optilux 57) was applied to scoliosis radiography and compared with a full-size rare-earth screen/film technique. When scoliosis radiography (PA-projection) was performed on 25 adolescent patients, the photofluorographs were found to be of comparable diagnostic quality with full-size films. A close correspondence between the imaging techniques was found in the Cobb angle measurements as well as in the grading of rotation with the pedicle method. The use of photofluorography results in a radiation dose reduction of about one-half and considerable savings in direct imaging costs and archive space. In our opinion the method is particularly well-suited for follow-up and screening evaluation of scoliosis, but in tall patients the image field size of 40 x 40 cm restricts its usefulness as initial examination.

Adolescent↗
PubMed1988

Image-intensifier photofluorography and conventional chest radiography: comparison of diagnostic efficacy.

Photofluorography with a large image intensifier, which provides an image field of 40 x 40 cm, reduces both the radiation dose and the imaging costs in chest radiography as compared with the film-screen technique. The two techniques were evaluated in a clinical study of 135 patients with suspected chest abnormalities. Photofluorographs and film-screen chest radiographs were interpreted independently by three radiologists. The diagnoses were confirmed by CT, follow-up radiographs, and clinical records. Among the 135 patients, 75 had primary lung cancer, 39 had pulmonary nodules, 52 had hilar or mediastinal abnormalities, 17 had pleural fluid, and 45 had pneumonic or atelectatic changes. Twenty-three normal subjects were included. Differences in diagnostic accuracy, measured by sensitivity and specificity, were not statistically significant. A larger number of true-positive cases (65%) with peripheral lung nodules were found by photofluorography than by film-screen radiography (54%) (p less than .05). The results suggest that the diagnostic accuracy of chest images made by photofluorography is sufficient to warrant using it instead of the film-screen technique in routine chest radiography, especially to detect lung tumors and metastases.

Humans↗
PubMed1986

Evaluation of an anatomical compensation filter for chest radiography.

An anatomical compensation filter for improving the radiographic demonstration of the mediastinal and retrocardiac areas of a chest radiograph has been evaluated. The filter, made of a transparent, light-weight lead-plastic material was attached to the X-ray collimator housing. The device reliably improved the visibility of normally underpenetrated areas without producing detectable artefacts, provided the patient was correctly positioned. Hilar structures were also slightly better visualised. At the same time there was no statistically significant deterioration in visualisation of peripheral pulmonary vessels or parenchymal structures. Rib details and pleural calcifications were less well seen, however, a result that was to be expected because of the X-ray beam hardening.

Aged↗
PubMed1984

Visual detection and physical characteristics of roentgenographic systems. Investigations on chest imaging chains.

The relationship between physical characteristics (physical resolution, large object contrast and radiographic mottle) and visual detection parameters was evaluated in a water phantom. To measure visual observer performance a minified Snellen E-plate made of gold (three contrast zones) and a high contrast lead bar test pattern were investigated. A trial to test four types of equipment chains for chest radiography was further done with the E-plate technique by simulating a clinical radiography with an Alderson thorax phantom. The observer performance of the high contrast lead bar test pattern showed a good linear correlation to the physical parameters. However, none of the physical system-related parameters fully predicted the visual detectability when the equipment chains were investigated with the E-plate technique. In Alderson phantom studies the rare-earth screens and the air gap technique considerably reduced the radiation dose compared with that of the ordinary grid technique chest radiography, without impairing visual detectability significantly. The RP- and spotfilm techniques showed relatively poor properties of visual detectability.

Models, Structural↗