Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0022116 (ischemia)
 91,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The need to relieve muscle swelling and secondary vascular impairment of an extremity may occur following a variety of conditions. Regardless of the type of insult, massive swelling of an extremity can result in ischemic necrosis of muscle as a result of tamponade produced by restrictive circulferential fascia. When intracompartmental pressure approaches or exceeds arterial pressure, a portion or the entire extremity may be in jeopardy. Fasciotomy is one of the most important adjunctive procedures available to assure survival of an extremity with altered distal circulation resulting from massive swelling. Its importance has been stressed infrequently in the literature. The indications for its use are outlined in a variety of clinical situations. The proper techniques have few complications and much to offer with regard to limb salvage and reduction of morbidity. Fasciotomy does not preclude correction of the underlying cause for restrictive muscle tamponade when possible, nor can it be expected to reverse well established ischemia. Early and liberal use of fasciotomy is advocated when the outlined indications prevail.
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PMID:Compartmental syndromes in peripheral vascular surgery. 119 56

Two patients with carbon monoxide poisoning are presented, both of whom suffered rhabdomyolysis complicated by acute renal failure. One patient, an attempted suicide, developed a compartment syndrome of the right thigh that required fasciotomy and recovered after a period of hemofiltration and hemodialysis. Muscle biopsy appearances were consistent with partial muscle infarction. The other patient, rescued from a smoke filled room, exhibited raised creatine kinase but no evidence of muscle swelling. He developed anuric renal failure and adult respiratory distress syndrome and died despite maximum intensive care. Muscle biopsy showed early evidence of muscle necrosis. In both cases there was a marked reduction of enzyme activities in the muscle biopsy consistent with metabolic derangement. Although there was a clinical compartment syndrome in the first case, there was no muscle swelling at the time of biopsy or subsequently in the second case. A direct toxic effect of carbon monoxide may thus have been an important mechanism contributing to the muscle necrosis in the second case, although local ischemia may have been an exacerbating factor in the first case.
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PMID:Rhabdomyolysis and acute renal failure following carbon monoxide poisoning: two case reports with muscle histopathology and enzyme activities. 151 16

Crush injuries are ubiquitous, common sequelae in victims of seismic, industrial and military catastrophes, and were considered to be mainly due to ischemia of the affected limbs. Our clinical experience suggests that early in the crush syndrome, interference with the circulation may occur but is rare. The predominant earliest lesion in the crush syndrome is postulated to be pressure-stretch myopathy, rather than ischemic myopathy. It is proposed that at the membrane level, stretch increases sarcoplasmic influx of Na, Cl, H2O and Ca down their electrochemical gradient. Energy-requiring cationic extrusion pumps work at maximal capacity, but are unable to cope with the increased load. This results in cell swelling and increase in cytosolic and mitochondrial calcium with activation of autolytic destructive processes and interference with cellular respiration. Extensive muscle swelling may cause late muscle tamponade and myoneural ischemic damage (compartmental syndrome). Thus, whereas prevalent theory suggests that the sarcolemmal cationic pump activity is attenuated in the crush syndrome due to early ischemia, we propose that the cationic extrusion pump is maximally activated as in the amphotericin B model. Because the cationic pump is maximally activated in the stretched muscle and in cells exposed to amphotericin, these models rapidly deplete their scarce ATP stores and are susceptible to hypoxia in the face of initially normal circulation.
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PMID:The mechanism of muscle injury in the crush syndrome: ischemic versus pressure-stretch myopathy. 227

Postischemic limb swelling following reperfusion may be related to microvascular changes associated with ischemia. We used lymph-to-plasma total protein concentration ratios (L/P) and lymph flow (QL) as an index of transvascular exchange in the intact dog hindlimb during steady state (C) (1 hr), ischemia (I) (6 hr), and reperfusion (R) (3 hr). Central pressures, femoral arterial and venous pressures (PA, PV) and QL were recorded every 15 min. Lymph was collected from a femoral lymphatic in the passively flexed leg (50 cycles/min). Three groups of animals were studied: GI, sham-operated (N = 5); GII, moderate ischemia (N = 7, PA = 30-45% C); and GIII, severe ischemia (N = 7, PA = 5-20% C). In GI, QL gradually increased over 10 hr without change in L/P. Moderate ischemia produced a decrease in QL, 3.55 +/- 2.02 mg/hr to 0.92 +/- 0.53 mg/hr (P less than 0.0001), and QL remained below baseline during R with no change in L/P over the 10 hr. Severe ischemia produced a similar decrease in QL, 1.91 +/- 2.05 mg/hr to 0.15 +/- 0.1 mg/hr (P less than 0.01); however, an increase to 2.56 +/- 2.14 mg/hr occurred during R. Severe ischemia increased L/P 0.42 +/- 0.08 to 0.64 +/- 0.23 (P less than 0.001) and remained elevated during R at 0.63 +/- 0.18 (P less than 0.001). An increase in the wet-to-dry weight ratio of ischemic to nonischemic muscle after reperfusion was noted only in GIII, 3.82 +/- 1.17 vs 2.60 +/- 0.45 (P less than 0.04). Severe ischemia produces changes in vascular integrity which augment protein flow. Prevention of these vascular changes may help to minimize the muscle swelling of reperfusion.
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PMID:Transvascular protein movement in the intact ischemic hindlimb. 365 39