Effects of cast-bracing of the knee on physical performance in healthy subjects.

Effects of application of a hinged cast-brace on thigh muscle strength and physical performance tests were studied in eight healthy volunteers. The cast-brace was applied to one leg for four weeks. The subjects were free to move around. The extra loading by the cast-brace was determined in a progressive uphill walk test on a treadmill with measurements of oxygen uptake, heart rate and plasma lactate concentration. Submaximal oxygen uptake in the uphill walk test was raised significantly (average 9%) on the day after application. After four weeks of cast-brace wearing the submaximal oxygen uptake in the uphill walk test had decreased, but remained elevated (average 4%) even one day after removal. Heart rate was significantly higher (average 7%) during cast application and after removal. Plasma lactate concentration, however, was not influenced. To investigate the effect of four weeks cast-bracing various performance tests to judge the thigh muscle function were taken before application and after removal. No significant changes in peak torque of knee flexion and extension, in physiologic variables at submaximal running pace during treadmill exercise, maximal running speed, 60 m dash, or in jump height were found. In conclusion, cast-bracing of a healthy knee for four weeks has no significant effects on physical performance after removal.

Functional and morphological adaptations following four weeks of knee immobilization.

Immobilization of the knee as part of the treatment in bone or joint lesions leads to atrophy and consequently loss of functionally. In patients this atrophy and loss of functionality is difficult to quantify because of interfering symptoms and missing baseline data. In the present study structural and functional changes in thigh muscles were examined in eight healthy volunteers of whom one leg was immobilized in a cast for four weeks. Quadriceps cross-sectional area determined with computed tomography was 21% +/- 7% diminished after four weeks immobilization (p < 0.05). Muscle biopsies from the musculus vastus lateralis revealed an 16% decreased fiber diameter (p < 0.05) and no significant shift in fiber types. Isokinetic strength measurements of knee extensors and flexors demonstrated a fall in peak torque of 53% +/- 9% and 26% +/- 13% at an angular velocity of 60 deg.s-1 (p < 0.01). Aerobic power in one-leg-cycling exercise was not significantly affected, but isokinetic quadriceps endurance work decreased from 9.1 kJ to 5.6 kJ (p < 0.05). Despite the fall in quadriceps performance the subjects had only minor functional complaints for a few days. It is concluded that immobilization of the knee is an important factor in the development of thigh muscle atrophy in patients and should therefore be diminished as much as possible.

Methods of decision analysis: protocols, decision trees, and algorithms in medicine.

Algorithms, decision trees, and protocols are defined and explained since they constitute an accepted part of clinical decision analysis and application to clinical care. Algorithms are particularly useful for common clinical problems where uncertainties are unlikely. Decision trees are helpful when--as usually occurs in difficult clinical decisions--there are problems in probability. Clinical protocols, which, at best, are based on algorithms and decision trees, provide instruction of how to best treat a patient given the strict definitions of the clinical problem. These techniques are, in essence, merely graphic representations of a logical scientific approach to clinical problems. Criticisms of these techniques center on their rigidity and the automatic unthinking cookbook medicine they might sponsor. It is concluded that if these techniques are wisely designed and, even more importantly, wisely administered with an understanding flexibility, they can lead to both economy and patient benefit.

Gallstone obstruction of the intestine: an analysis of ten patients and a review of the literature.

Ten patients with gallstone ileus were studied to evaluate diagnostic and therapeutic procedures. The preoperative diagnosis was correct in four patients. All patients underwent laparotomy. In five patients, stones were removed by enterotomy and in three patients the obstruction was relieved by manual propulsion of the stones. One-stage small-bowel resection, cholecystectomy, and biliary enteric fistula repair were performed in two patients. Four patients had uneventful recovery. One episode of recurrent gallstone ileus was encountered. Three patients died of septic complications. It is concluded from the study and from a review of the literature that treatment should be aimed at relieving the obstruction, without performing additional surgical procedures, such as cholecystectomy and fistula repair. Secondary biliary surgery is to be performed only in patients with recurrent biliary disease.

The high thoracic sympathetic nerve system--its anatomic variability.

Upon studying microscopically and macroscopically 18 resection preparations of upper thoracic sympathectomies it is clear that the variability in the anatomy of the sympathetic nervous system in connection with the spinal nervous system is higher than has always been described. A fine network of smaller and larger nerve bundles was found which connect the sympathetic and spinal nerve systems. Light microscopical perikarya were identified in many nerve bundles. These findings have an important impact on the concept of the effectiveness of thoracic sympathectomy.

Strain gauge plethsymography in ischemic handsyndromes.

In sixteen patients with ischemic handsyndromes, strain gauge plethysmography was used as a noninvasive diagnostic test. Contrast-arteriography was available for comparison. These patients demonstrate the role for a noninvasive test in selecting patients with Raynaud's phenomenon or asphyxia for arteriography.

24-hour systemic antimicrobial prophylaxis with gentamicin and metronidazole, or metronidazole alone, in elective colorectal surgery after mechanical bowel preparation with mannitol and whole gut irrigation.

In a prospective randomized trial, systemic antimicrobial prophylaxis with metronidazole and gentamicin was compared to the administration of metronidazole alone in elective colorectal surgery. In both groups, an identical mechanical large-bowel preparation was performed. In order to reduce the duration of the whole-gut irrigation, a 10% mannitol solution was administered before the irrigation procedure. Although no serious infections were observed in either group, the incidence of superficial wound infections was relatively high: 19% in the group with metronidazole and gentamicin prophylaxis and 25% in the other group. From all these wounds E. coli was isolated, and no obligate anaerobic bacteria were cultured. This high rate of wound infections is most likely caused by an overgrowth of E. coli after irrigation, due to the residues of mannitol in the colon, which serve as a nutrient for E. coli. It is concluded that mannitol should not be used in the preoperative mechanical preparation of the large bowel before elective colorectal surgery.

Assessment of aortoiliac disease using hemodynamic measures.

To study the role of accurate hemodynamic assessment of aortoiliac disease, intra-arterial pressure measurements of 100 aortoiliac segments were compared with Doppler velocity waveform analysis and contrast arteriography. By applying the statistic kappa, we assessed the degree of agreement among the three methods corrected for chance. The agreement between pressure measurements and contrast arteriography provided a kappa of 0.41, as did the agreement between pressure measurements and velocity waveform analysis. Our results indicate that contrast arteriography and Doppler studies underestimate hemodynamically significant aortoiliac disease. Since the correlation is so poor, it is essential to use intra-arterial pressure measurements in every patient who is a candidate for surgery.

The clinical value of preoperative indirect systolic ankle pressure measurements in wound healing after amputation of the lower extremity.

With the intention towards more distal amputation of the lower extremity for peripheral vascular disease, failure of amputation wound healing remains a common clinical problem. Because calf blood flow correlates well with the indirect systolic ankle pressure, this pressure could be a prognostic guide to the outcome of amputation wound healing. To evaluate the clinical role of systolic ankle pressure measurements for selecting the most appropriate level of amputation, data of 93 patients undergoing 100 amputations were studied retrospectively. Of the 54 initial below knee (BK) amputations 83% healed and 17% failed to heal. Of the 46 initial above knee (AK) amputations 88% healed and 12% needed stump correction. Although all extremities with a systolic ankle pressure of more than 70 mm Hg healed in BK amputations there was no clinical predictive value of indirect systolic ankle pressure measurements. There was no difference in wound healing between diabetic and non-diabetic patients.

Dome fracture of the talus.

Three cases of transchondral fracture of the dome of the talus are reported. Two were treated surgically, one conservatively. A review of the literature is presented and the relative values of surgical intervention and conservative therapy are discussed.

Clinical and rheological studies in patients with intermittent claudication.

While the resistance to flow offered by means of arterial narrowing and the collateral arteries are the major determinants affecting peripheral flow, there may be a contribution by those elements which affect the viscosity of the blood. To evaluate these factors, haematocrit, red blood cell aggregation and plasma viscosity were measured in 100 patients with occlusive arterial disease of the lower extremities. Disturbances in these parameters were noted and appeared to be related to the severity and extent of the occlusive disease. However, whether these factors contribute to the cause of intermittent claudication remains uncertain.

The value of objective measurements to select patients who are malnourished.

Several studies have attempted to define nutritional parameters that can be used to select malnourished hospitalised patients for nutritional support. A combination of objective nutritional parameters was evaluated in a group of 50 patients selected for total parenteral nutrition on clinical grounds only and compared with a control group. This control group consisted of 38 patients who were admitted for elective minor surgical procedures such as varicectomy and hernia repair. On a subset of 18 objective nutritional measurements, discriminant analysis was performed. In the evaluation it was shown that a combination of albumin (ALB), prealbumin (PALB), total lymphocyte count (TLC) and the percentage of ideal weight (PIW) was the most useful combination of nutritional tests in discriminating a chosen malnourished (M) group and a control group who were declared not malnourished (NM). With this combination the patients were correctly classified in 93% with a sensitivity of 93% and a specificity of 94%.

Chylothorax after gastric resection.

Traumatic chylothorax has been described as an uncommon complication of various thoracic and cervical surgical procedures. No previous reports have been made of chylothorax following gastric resection for malignancy. Two cases of chylothorax following damage to the thoracic duct during gastric resection for malignancy are presented and the literature is reviewed. The condition was successfully managed by conservative means. Pleural aspiration, combined with total parenteral nutrition in one case and positive end-expiratory pressure ventilation in the other, resulted in complete resolution of the chylous effusions.

Prospective study on the incidence of complications of right heart catheterization.

Indications for hemodynamic assessment by right heart catheterization include shock, pulmonary edema, severe trauma and sepsis. The introduction of the catheter and the location of the tip in the pulmonary artery, however, can cause severe complications. In the present study the incidence of complications was observed in 93 consecutive right heart catheterizations in critically ill patients with no evidence of recent myocardial infarction. The low incidence of complications during introduction and with the catheter tip located in the pulmonary artery justifies right heart catheterization in patients with hemodynamic and/or respiratory instability treated in an intensive care unit.