Intramuscular pressure, blood flow, and skeletal muscle metabolism in patients with venous claudication

Nine patients with chronic iliac vein obstruction and venous claudication were investigated. Intramuscular pressure was measured in the anterior tibial and the deep posterior compartments in both legs at rest and during exercise. The pressures were significantly higher in the leg with iliac vein obstruction (39 +/- 10 mm Hg) than in the contralateral leg (26 +/- 12 mm Hg) at rest as well as during exercise (60 +/- 16 mm Hg and 41 +/- 15 mm Hg, respectively) in the deep posterior compartment. Similar changes were observed in the anterior tibial compartment. Muscle water content was higher (P less than 0.01) in the obstructed leg and contributes to the explanation for the high intramuscular pressure in this leg. Muscle blood flow, adenosine triphosphate, phosphocreatine, and lactate were determined in the gastrocnemius muscles at rest and at exercise. Muscle blood flow, measured with the 133xenon clearance technique, was lower in the obstructed leg (17.5 ml/min, 100 gm) than in the control leg (28.1 ml/min, 100 gm) during exercise. Lactate increased more (P less than 0.05) in the obstructed leg. It is suggested that pain in venous claudication is caused by the high intramuscular pressure, and therefore fasciotomy may be useful in the treatment of this disorder.     

Intramuscular pressure in the supraspinatus muscle

Shoulder pain correlated to manual labour is an increasing problem. The etiology is multifactorial and often unclear. High local muscle load and muscle ischemia in the supraspinatus muscle is present in elevated arm positions, as shown in several electromyographic studies. The purpose of this study was to evaluate intramuscular pressure (IMP) as a way to describe local muscle load in the supraspinatus muscle. Measurements were made in 15 arm positions, and with hand loads of 0, 1, or 2 kg weight, in 12 shoulders. The IMP was recorded with microcapillary infusion technique. The method was found to be suitable in recording IMP at rest and during exercise. High intramuscular pressures, i.e., above 50 mm Hg (6.7 kPa), were seen in moderate humeral abduction. The IMP increased further in abduction up to 90 degrees, where mean IMP was 122 mm Hg (16.2 kPa). Added hand load increased intramuscular pressure in all positions except in shoulder flexion of 135 degrees. The study thus demonstrated that intramuscular pressure offers important information about the load on the supraspinatus muscle in different positions of the arm. The results indicate that fatigue and shoulder pain related to elevated arm positions may be caused by muscle ischemia induced by the high intramuscular pressure present in these positions.     

Changes in tibial venous blood flow in the evolving compartment syndrome

A sustained increase in muscle compartment pressures can cause tissue necrosis. When compartment pressures exceed recumbent tibial vein pressures, blood flow in tibial veins may be impaired. These changes can be detected by Doppler venous flow evaluation. In 26 patients at risk for compartment syndrome, serial examinations, Doppler venous flow, and measurements of compartment pressures were performed. All patients with abnormal Doppler venous flow results had or developed neuromuscular deficits. Patients with normal Doppler venous flow either initially or after fasciotomy did not develop the compartment syndrome. This syndrome can be evaluated and followed up sequentially by measuring Doppler venous flow in tibial veins.     

Pathophysiology and pressure measurement in compartment syndrome

Traumatic or ischemic damage of the musculature and soft tissue may cause compartment syndrome. In trauma, mechanical influences provoke humeral disorders and liberation of vasoactive substances with early onset of compartment syndrome, but isolated total ischemia of more than 6 h is commonly followed after revascularization by compartment syndrome caused by post-ischemic dilation of vessels. An understanding of the pathophysiology in compartment syndrome provides a better possibility of predicting this severe complication in trauma and vascular surgery patients. Several techniques are described for intracompartmental pressure monitoring. In normotensive patients, an intracompartmental pressure of more than 40 mmHg indicates "apparent" compartment syndrome, while pressures between 30 mmHg and 40 mmHg are interpreted as "imminent" compartment syndrome. In these cases therapeutic/prophylactic dermatofasciotomy is necessary. In hypotensive patients the lower limit for conducting a dermatofasciotomy must be reduced. According to the pathophysiology, an intracompartmental pressure of about 30 mmHg for more than 6 h duration must be treated by dermatofasciotomy.     

Endoscopic compartment release for chronic exertional compartment syndrome

Chronic exertional compartment syndrome is a condition that typically fails conservative management and requires a fasciotomy for the patient to return to activity. Fasciotomies performed through single or multiple incisions may fail to fully release the fascia of the afflicted compartment(s) and also may result in injury to neurovascular structures that cannot be visualized. Endoscopic assistance may minimize the intraoperative and postoperative complications associated with compartment release and offer improved cosmesis. This article describes an endoscopically assisted technique using a balloon dissector designed to address the shortcomings of open and semi-blind techniques.     

Fasciotomy for chronic compartment syndrome

During 1977 and 1978, we operated on 34 patients with chronic anterior tibial compartment syndrome. Surgery consisted of subcutaneous fasciotomy of the anterior crural compartment under local anesthesia. Twenty-three patients were operated on bilaterally. The mean follow-up was 10 years. One patient was lost to follow-up, leaving a total of 56 legs for assessment. The long-term result was excellent in 31 legs, good in 10, fair in 11, and poor in 4. There was one recurrence. This was relieved by refasciotomy.     

Fasciotomy for chronic compartment syndrome

During 1977 and 1978, we operated on 34 patients with chronic anterior tibial compartment syndrome. Surgery consisted of subcutaneous fasciotomy of the anterior crural compartment under local anesthesia. Twenty-three patients were operated on bilaterally. The mean follow-up was 10 years. One patient was lost to follow-up, leaving a total of 56 legs for assessment. The long-term result was excellent in 31 legs, good in 10, fair in 11, and poor in 4. There was one recurrence. This was relieved by refasciotomy.     

Tissue pressure and perfusion in the compartment syndrome

Three objective indicators of the need for muscle compartment decompression were evaluated in an animal model and in clinical studies.In the animal model, there was linear correlation between compartment pressure and graded external counterpressure (r = 0.99, p < 0.001) and between decreasing MBF and increasing compartment pressure (r = -0.85, p < 0.01). MBF was undetectable with external counterpressure greater than 80 mm Hg.In patients, Doppler evaluation of distal arteries was an inconsistent guide for compartment decompression. There was correlation between MBF and the difference between diastolic blood pressure and compartment pressure (r = 0.66, p < 0.05). All patients requiring decompression had MBF values less than 1 cc/min/100g.Determination of MBF and/or compartment pressure appear to be useful early indicators of the need for compartment decompression.     

Intramuscular deltoid pressure during shoulder arthroscopy

A large amount of fluid extravasation into the surrounding muscle and soft tissue may occur during arthroscopy of the shoulder and particularly of the subacromial space. The tense swollen appearance of the shoulder has caused concern that the intramuscular deltoid pressure may become elevated to dangerous levels. Therefore, the intramuscular deltoid pressure was monitored in this study using a slit catheter. Although it was found that the intramuscular pressure became transiently elevated during the arthroscopic procedures, in every case the pressures promptly returned to normal levels within 30 min postoperatively. The clinical swelling and tenseness remained for a longer period. Despite a sometimes alarming amount of swelling during shoulder arthroscopy, intramuscular pressure elevations were only sustained for a short time and returned to normal levels very quickly after the cessation of fluid infusion.     

Cerebral blood flow during increased subarachnoid pressure

Summary In rhesus monkeys and cats cerebral intracranial pressure was increased by intracranial fluid injection. Increased liquor pressure was transferred to the superficial cerebral veins, which caused a reduction of cerebral perfusion pressure. An arterial pressure response occurred as soon as the perfusion pressure was less than 100 mm Hg. The pressure increase was dependent on the percent rate of perfusion pressure decrease in relation to the systemic arterial pressure. Carotid flow measured in monkeys showed a slight reduction as long as the perfusion pressure was higher than 50 mm Hg but was marked when it fell below that value. The systemic arterial pressure had a significant influence on cerebral vessel resistance independent from the perfusion pressure. During increased intracranial pressure the cerebral blood volume seemed to be moderately decreased.     

Intramuscular and blood pressures in legs positioned in the hemilithotomy position : clarification of risk factors for well-leg acute compartment syndrome

BACKGROUND: Acute compartment syndrome has been widely reported in legs positioned in the lithotomy position for prolonged general surgical, urologic, and gynecologic procedures. The orthopaedic literature also contains reports of this complication in legs positioned on a fracture table in the hemilithotomy position. The purpose of this study was to identify the risk factors for development of acute compartment syndrome resulting from this type of leg positioning. METHODS: Eight healthy volunteers were positioned on a fracture table. Intramuscular pressures were continuously measured with a slit catheter in all four compartments of the left leg with the subject supine, in the hemilithotomy position with the calf supported, and in the hemilithotomy position with the heel supported but the calf free. Blood pressure was measured intermittently with use of automated pressure cuffs. RESULTS: Changing from the supine to the calf-supported position significantly increased the intramuscular pressure in the anterior compartment (from 11.6 to 19.4 mm Hg) and in the lateral compartment (from 13.0 to 25.8 mm Hg). Changing from the calf-supported to the heel-supported position significantly decreased intramuscular pressure in the anterior, lateral, and posterior compartments (to 2.8, 3.4, and 1.9 mm Hg, respectively). The mean diastolic blood pressure in the ankle averaged 63.9 mm Hg in the supine position, which significantly decreased to 34.6 mm Hg in the calf-supported position. Changing to the heel-supported position had no significant effect on the diastolic blood pressure in the ankle (mean, 32.8 mm Hg). The mean difference between intramuscular pressure and diastolic blood pressure in the supine position was approximately 50 mm Hg in each of the four compartments. This mean difference significantly decreased to <20 mm Hg in the calf-supported position and then, when the leg was moved into the heel-supported position, significantly increased to approximately 30 mm Hg in all compartments. CONCLUSIONS: The combination of increased intramuscular pressure due to external compression from the calf support and decreased perfusion pressure due to the elevated position causes a significant decrease in the difference between the diastolic blood pressure and the intramuscular pressure when the leg is placed in the hemilithotomy position in a well-leg holder on a fracture table. Combined with a prolonged surgical time, this position may cause an acute compartment syndrome of the well leg. Leaving the calf free, instead of using a standard well-leg holder, increases the difference between the diastolic blood pressure and the intramuscular pressure and may decrease the risk of acute compartment syndrome.     

Diagnosis and management of chronic compartment syndrome

BACKGROUND: This article describes the diagnosis and management of chronic compartment syndrome and functional popliteal entrapment syndrome, unusual causes for claudication in young adults. METHODS: A total of 276 patients (<50 years old) with isolated muscle cramping, swelling, and plantar paresthesia were routinely evaluated with compartment pressures (normal < 15 mm Hg), stress plethysmography, and selectively evaluated with pulse volume recordings and arteriography. RESULTS: Patients were young (mean 28.4 years) with long-standing symptoms (mean 24 months), affecting 1 or both lower extremities (32% vs 68%, respectively). Of the patients, 84 were male (30%) and 192 were female (70%). Common symptoms were isolated muscle cramping (100%) or swelling (40%), and plantar paresthesia (20%). Of 436 treated compartments, 316 were anterolateral, 70 deep-posterior, and 50 superficial-posterior. Mean compartment pressure was 28 mm Hg. Resting pulse volume recordings were abnormal in 6 patients (2.5%); 82 had positive popliteal entrapment tests (30%), but symptoms were present in only 21 (9.7%). Open fasciectomy was performed in all patients with chronic compartment syndrome or functional entrapment. Local anesthesia was used in 243 (88%) and general in 33 patients (12%). Mean follow-up was 60 months. Of the 276 patients, 92% had full relief of symptoms and returned to normal daily or athletic activity. Eight percent obtained symptomatic relief, but activity was limited because of new compartment symptoms or other orthopedic injury. CONCLUSIONS: Open fasciectomy for chronic compartment and functional entrapment syndromes is effective therapy.     

Absolute compartment pressure versus differential pressure for the diagnosis of compartment syndrome in tibial fractures

We studied 39 patients with 42 diaphyseal tibial fractures in whom we suspected a high risk for the development of a compartment syndrome. We measured the anterior absolute compartment pressure (ACP) every 12 h for 72 h and also recorded the differential pressure (ΔP=diastolic blood pressure−ACP). Fasciotomy of the extremity was only performed when the differential pressure was less than 30 mmHg for more than 30 min. The highest values of the ACP were recorded between 24 h and 36 h after admission. Three fractures had a differential pressure less than 30 mmHg and all were treated by fasciotomy. In three fractures the ACP was equal to or higher than 50 mmHg, of which two had a differential pressure less than 30 mmHg. The patients were followed up for a mean of 36 months (29–45). All fractures healed, and none of our patients showed any sequelae of compartment syndrome at their last review.

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Résumé Nous avons étudié 39 malades avec 42 fractures tibiales diaphysaires que nous avons suspecté d'un syndrome compartimental. Nous avons mesuré la pression du compartiment antérieure (ACP) chaque 12 h pendant 72 h et avons aussi enregistré la pression différentielle (ΔP=tension diastolique−ACP). Une fasciotomie de la jambe a été exécutée seulement quand la pression différentielle était inférieure à 30 mmHg pendant plus de 30 min. Les plus hautes valeurs de l'ACP ont été enregistrées entre 24 et 36 h après l'admission. Trois fractures avaient une pression différentielle de moins de 30 mmHg et toutes ont été traitées par fasciotomie. Dans trois fractures l'ACP était égale ou supérieure à 50 mmHg , avec, pour deux, une pression différentielle de moins de 30 mmHg. Les malades ont été suivis pendant une moyenne de 36 mois (29–45). Toutes les fractures ont guéri et aucun de nos malades n'a montré de séquelle d'un syndrome de compartiment à la dernière révision.

     

Intramuscular pressure and electromyography in the supraspinatus muscle at shoulder abduction

In ergonomic and biomechanic research, estimations of shoulder muscle load and evaluation of different measuring techniques are important. Intramuscular pressure (IMP), using the microcapillary infusion technique and bipolar intramuscular electromyography (EMG), was recorded from the same part of the supraspinatus muscle. In 12 subjects, IMP and EMG were recorded at shoulder abduction angles of 0 degrees, 30 degrees, 60 degrees, 90 degrees, and 135 degrees with no or a 1- or 2-kg hand load in each position. The shoulder torque was calculated for each test position. A correlation was found for both mean IMP and mean EMG versus shoulder torque if the position with extreme muscle shortening (135 degrees abduction) was excluded. IMP was high (greater than 50 mmHg) in almost all test situations. In seven other subjects, isometric force in abduction was correlated with IMP and EMG. Both methods showed an equally good correlation with external shoulder force, IMP gives as good an estimation of relative muscle force as EMG, but any comparison between EMG and IMP must be done at the same muscle length.     

Coronary blood flow during variation in coronary perfusion pressure

It is demonstrated that severe dysfunction occurs in the myocardial segment supplied by a critically stenosed coronary artery during hypotension, while in contrast an increase in coronary perfusion pressure (to the extent used in this experimental model) is not detrimental to regional myocardial function. If the results of these experiments are applied to clinical practice, it appears to be of primary importance to maintain normal blood pressure in patients with ischaemic heart disease, and it may even be preferable to increase the blood pressure slightly during the peri-operative period.