[Pathology in Third World countries. Experience in Cambodia ].
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Cambodia↗
Biomedical subjects
H U Völker
Publications and source records attributed to H U Völker.
Intramuscular pressure, tissue oxygenation and EMG fatigue measured during isometric fatigue-inducing contraction of the multifidus muscle.
Simultaneous measurement of intramuscular pressure (IMP), tissue oxygen partial pressure (pO(2)) and EMG fatigue parameters in the multifidus muscle during a fatigue-inducing sustained muscular contraction. The study investigated the following hypotheses: (1) Increases in IMP result in tissue hypoxia; (2) Tissue hypoxia is responsible for loss of function in the musculature. The nutrient supply to muscle during muscle contraction is still not fully understood. It is assumed that muscle contraction causes increased tissue pressure resulting in compromised perfusion and tissue hypoxia. This tissue hypoxia, in turn, leads to muscle fatigue and therefore to loss of function. To the authors' knowledge, no study has addressed IMP, pO(2) and EMG fatigue parameters in the same muscle to gain a deeper sight into muscle perfusion during contraction. As back muscles need to have a constant muscular tension to maintain trunk stability during stance and locomotion, muscle fatigue due to prolonged contraction-induced hypoxia could be an explanation for low back pain. Sixteen healthy subjects performed an isometric muscular contraction exercise at 60% of maximum force until the point of localized muscular fatigue. During this exercise, the individual changes of IMP, pO(2) and the median frequency (MF) of the surface EMG signal of the multifidus muscle were recorded simultaneously. In 12 subjects with a documented increase in intramuscular pressure, only five showed a decrease in tissue oxygen partial pressure, while this parameter remained unchanged in six other subjects and even increased in one. A fall in tissue pO(2) was associated with a drop in MF in only five subjects, while there was no correlation between these parameters in the other 11 subjects. To summarize, an increase in IMP correlated with a decrease in pO(2) and a drop in MF in only five out of 16 subjects. High intramuscular pressure values are not always associated with a hypoxia in muscle tissue. Tissue hypoxia is not automatically associated with a median frequency shift in the EMG signal's power spectrum.
Adult↗
[The importance of PET in searching the primary tumor site in CUP patients -- a case report].
A 58 years old male patient presented with a left cervical metastasis of a poorly differentiated squamous cell carcinoma, which was diagnosed by fine needle aspiration cytology. Clinical examination, MRT scans and panendoscopy did not detect the primary tumour site. The positron emission tomography localized an uptake of FDG in the left sided base of the tongue. The patient underwent an ipsilateral modified radical neck dissection and a lateral pharyngotomy. In the left tongue base an induration was palpable which was resected with security distance. The histopathological examination showed a poorly differentiated squamous cell carcinoma with a largest extension of 5 mm x 10 mm.
Carcinoma, Squamous Cell↗
[Acute compartment syndrome. Results of a clinico-experimental study of pressure and time limits for emergency fasciotomy].
BACKGROUND: Acute compartment syndrome of the leg is to be regarded as a traumatological emergency. Most specialists already agree that only a timely operative decompression of the afflicted compartment can prevent serious tissue damage. What still remains subject to discussion, however, is the precise tissue pressure above which the operation becomes imperative. Experimental human studies focusing on tissue pressure and muscle oxygenation have not yet been carried out. It was thus the aim of the present study to analyze oxygen partial pressure of the anterior tibial muscle and peroneal action potential in a model compartment syndrome in man. METHODS: In 22 healthy, normotensive volunteers, constant pressure values from 0 to 100 mmHg were induced in the anterior tibial muscle with antishock trousers. Over a period of up to 6 h measurements were made of (1) tissue pressure, (2) intramuscular oxygen partial pressure (pO2), and (3) muscle response potential (MRP) of the n. peroneus profundus by electroneurography. RESULTS: We achieved a 97.7% (Q25%/Q75%: 89.2/99.8) transfer of the pneumatic pressure to the lower leg. Already at intramuscular tissue pressures of 30-40 mmHg, hypoxia and reduction of MRP appeared. A reduction of the MRP to zero and pO2 < 1 mmHg was observed from a pressure of 50 mmHg. Tissue pressure values of over 75 mmHg resulted almost without exception in anoxia of the muscle. CONCLUSIONS: Even under normal perfusion conditions, already slight increases in pressure of above 30 mmHg lead to reduced tissue oxygenation and neural function. We have to consider that with additionally traumatized muscle the ischemic tolerance is markedly reduced and due to unknown influences such as local vasoreactivity and capacity of autoregulation the nutritive perfusion cannot be determined. In the case of a severely injured muscle, to be on the safe side decompressive fasciotomy should therefore be carried out if pressure values remain above 30 mmHg.
Adult↗
[Decubitus ulcer. Basic treatment intervention is pressure unloading].
With an incidence of between 3 and 34%, decubitus ulcers are common chronic wounds, many of which can be avoided by prophylactic measures. The most effective preventive measure is relieving pressure on the endangered part of the body, and this is most easily achieved by regularly changing the patient's position in bed. Since, however, this is not always possible for staff-shortage or illness-related (e.g. fractures of the spine) reasons, modern pressure-relieving systems are being increasingly used. The range of options extends from simple foam plastic underlays to water-filled cushions to pneumatic cushions or beds filled with tiny glass beads. Selection of the most appropriate system is often difficult. For effective prophylaxis, determination of the individual risk of developing a bedsore with the aid of special scales makes good sense. In this way, the measures required can be adapted to the particular needs of the individual patient. New approaches to decubitus ulcer prevention and wound management may help to ensure effective care of the endangered or affected patient.
Adolescent↗
[The significance of intracompartmental pressure values for the diagnosis of chronic functional compartment syndrome. A meta-analysis of research studies of pressures in anterior M. tibialis during exercise stress].
INTRODUCTION: The chronic exertional compartment syndrome of the musculus tibialis anterior is thought to be responsible for a major part of complaints of the lower leg among active sportsmen. There is an important role of tissue pressure measurement in diagnosing chronic anterior compartment syndrome during muscular activity. However, there is a controversial debate about the relevant parameters. METHODS: Metaanalysis of all the 21 studies (1979-1998) measuring intracompartmental pressures during muscular activity. Parameters of analysis: type of exercise, catheter technique, recommendations of diagnostic criteria. RESULTS: Analysis of literature shows that there has been no standardisation concerning the type of muscular exertion (isometrics for 5-10 min, exercise on the treadmill between 3.2 and 12 km/h). In 8 of the 21 studies the results have been attained through the unsuitable Wick-catheter-technique. In the overall view none of the suggested criterions for diagnosis is taken up by other teams. There are considerable variations up to 500% regarding the recommended parameters. CONCLUSIONS: From all studies no uniform recommendation for parameters of diagnostic relevance can be derived. On this background it should be demanded that future research is conducted by a uniform regimen for examination and modern technique of measuring with a high temporal resolution. Under these standardised conditions the investigated parameters of the intracompartmental pressure curve should be reconsidered once more regarding diagnostic predictability by calculations of specifity and sensitivity.
Adult↗
[The effect of soft care mattresses on subcutaneous tissue pressure and pO2 over the os sacrum].
In this study the influence of soft-care systems on subcutaneous tissue pressure and pO2 has been examined. In 14 volunteers 3 probes were implanted over the os sacrum for measurement during the 20-minute periods. Then the probands were asked to lie on a standard mattress, on 8 static beds of various kind and on 3 dynamic soft-care systems. The clinical mattress pressure values amounted to 25.5 mm Hg (+/- 5.2; n = 14). The gell-cushion showed increased values (26.9 +/- 9.5 mm Hg; n = 5). Compared to the standard mattress the other systems showed reductions in pressure from 32.7% to 83.1%. The lowest pressure was recorded with an air-supported mattress (8.3 +/- 2.3 mm Hg; n = 5). The pO2 initial values before lying down varied greatly from individual to individual (26.9-71.3 mm Hg). In the course of the 20-minute periods the pO2 value sometimes remained constant, sometimes increased and at other times it decreased. Under extreme conditions (with 8 probands asked to lie on the floor) a correlation (r = -0.787) between pressure and pO2 was observed (pressure values between 20.6 and 192.9 mm Hg). The results indicate the use of modern soft-care systems depending on the individual risk of pressure sores.
Adult↗
[Reduced muscular oxygen tension and nerve impulse transmission from antishock hose. Reduction of oxygen tension in the tibial muscle and impulse transmission in the peroneal nerve from pneumatic -1 pressure from antishock hose].
OBJECT OF THE STUDY: The aim of the study was to assess, whether the pneumatic pressure of an antishock-trouser (AST) of 20-40 mm Hg induces a decreased oxygenation of the anterior tibial muscle and attenuates muscular response potential (MRP) of n. peronaeus profundus? METHODS: Among 22 normotensive, healthy volunteers the AST were tested by applying pressure values between 0 and 100 mm Hg and measuring the intracompartmental pressure, the muscular oxygen pressure as well as the MRP by electroneurographic means within a period of 6 hours. RESULTS: The median initial intracompartmental pressure value of the m. tibialis anterior was 12.0 mm Hg (Q25%/Q75%: 8.9/17.3), the muscular oxygen pressure 14.8 mm Hg (Q25%/Q75%: 11.5/22.0). Transmission of the pneumatic AST-leg segment pressure to the muscle: 97.7% (Q25%/Q75%: 89.2/99.8). Already in the low AST pressure field (20-40 mm Hg) a severe hypoxia occurred in one case. A reduction of MRP was noticed at an AST pressure rate of 10 mm Hg. In 5 of 6 cases AST pressure values of 60 mm Hg led to pathological pO2-values within 5-20 minutes. Almost without exception AST-pressure rates < 60 mm Hg resulted in an anoxia of the muscle and loss of the MRP. CONCLUSIONS: We should demand that the AST are only applied with models where the pressure generated within the single segments can be controlled by pressure gauge. The application of the AST seems to be justified for polytraumatised in severe haemorrhagic shock where the risk of a local tissue ischemia with systemical consequences must deliberately be accepted.
Adult↗
[Respiratory and anesthetic gas flow monitoring].
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Anesthesia, Inhalation↗