Streptokinase clot lysis time in patients with ruptured intracranial aneurysms

Rhabdomyolysis induced by epsilon-aminocaproic acid

OBJECTIVE

To report a case of rhabdomyolysis associated with epsilon-aminocaproic acid (epsilon-ACA).

CASE SUMMARY

A 33-year-old female patient with chronic granulocytic leukemia was treated with epsilon-ACA for approximately 3.5 months for thrombocytopenic bleeding. The initial dosage was 4 g po q6h. One month after an increase in dosage to 5 g po 14h the patient developed severe lower extremity myalgia and marked weakness. Laboratory investigations revealed an elevated creatine kinase (CK), lactate dehydrogenase (LDH). aspartate aminotransferase (AST), and myoglobinemia. Epsilon-ACA was thought to be the causative agent and was discontinued. The patient received intravenous fluids to minimize renal damage due to myoglobin. Serum enzyme concentrations did not return to normal. The patient died of a central nervous system hemorrhage 1 week after the epsilon-ACA was discontinued.

DISCUSSION

There were 31 cases of epsilon-ACA-induced myopathies published in the literature (MEDLINE) from 1972 to June 1995. Of these, 10 cases were reviewed. In all cases, patients received epsilon-ACA in doses ranging from 16 to 36 g/d for more than 28 days. Clinical findings varied from extreme muscle weakness to myopathic changes in electromyelograms. All patients recovered following discontinuation of epsilon-ACA.

CONCLUSIONS

Long-term therapy with high-dose epsilon-ACA may produce muscle weakness or rhabdomyolysis. Patients who require long-term, high-dose epsilon-ACA therapy should be monitored for myoglobinuria and changes in serum CK, LDH, and AST, for myoglobinemia, for decreases in muscle strength, and/or for myalgia. Significant changes in these parameters compared with baseline values should suggest a need to discontinue epsilon-ACA therapy.

Fibrinolytic activity after subarachnoid haemorrhage and the effect of tranexamic acid

Seventy-four patients with recent subarachnoid haemorrhage were randomly allocated to placebo or tranexamic acid treatment. Fibrinolytic activity in the blood and cerebrospinal fluid was assessed before treatment, one week later and two weeks later. The natural history of fibrinolysis following subarachnoid haemorrhage was obtained from analysis of the placebo group. Following subarachnoid haemorrhage, fibrin degradation products and plasminogen activity in the cerebrospinal fluid were elevated. Subsequently, fibrin degradation products in the cerebrospinal fluid fell progressively over the following 2 weeks. Changes in cerebrospinal fluid plasminogen activity correlated with those of blood plasminogen activity. Complications such as rebleeding, hydrocephalus or cerebral thrombosis could not be predicted from analysis of fibrinolytic activity. Tranexamic acid treatment resulted in a reduction in cerebrospinal fluid and blood plasminogen activity. The relevance of fibrinolysis in cerebrospinal fluid and blood to the management of subarachnoid haemorrhage is discussed.

Rebleeding, ischaemia and hydrocephalus following anti-fibrinolytic treatment for ruptured cerebral aneurysms: a retrospective clinical study

350 patients with subarachnoid haemorrhage from aneurysmal rupture--admitted in the years 1966-1983--were selected for a retrospective controlled study on the efficacy of antifibrinolytic therapy (AFT). Patients treated with antifibrinolytics were divided into two groups, according to the day of hospital admission and onset of therapy, respectively between 0 and 3 days (SG 1) and between 4 and 7 days from SAH (SG 2); treated patients (260 cases) received i.v. tranexamic acid (6 gr/day) for at least two weeks. Patients admitted before 1974, not receiving antifibrinolytics (90 cases), were selected as controls and divided into two groups (CG 1 and CG 2), according to the day of admission. In the first study group (admission 0-3 days) the rebleeding rate within 2 weeks was 9% versus 23% in controls (p less than 0.01). The incidence of rebleeding within 3 and 4 weeks was also significantly lower (p less than 0.05) than in controls. No significant difference was observed in the rebleeding rate in treated and untreated patients with late admission (4-7 days). Mortality from rebleeding was 16% in the first study group versus 17% in controls; in the second study group the figure was 6% versus 8% in controls. Seventy-five cases of ischaemic disorders (29%) were registered in treated patients versus 13 cases in controls (14%; p less than 0.01). Thirty-seven patients receiving AFT (14%) developed significant ventricular dilatation requiring shunt insertion, versus one patient in the control groups (1%; p less than 0.001). Final outcome was similar in the 4 groups. In conclusion--according to our data--AFT modifies the behaviour of rebleeding and the patients' course, although it does not modify the outcome after SAH. Clinical use of antifibrinolytic therapy appears still justified in those patients who cannot be operated on in the acute stage after SAH, provided that an associated anti-ischaemic therapy is undertaken.

Antifibrinolytic agents in subarachnoid haemorrhage

For many years clinicians have used antifibrinolytic agents to try to reduce rebleeding after subarachnoid haemorrhage. Early studies of their effectiveness produced conflicting results. This paper re-evaluates the available trials and considers benefits in the light of potential complications. Present evidence conclusively demonstrates that epsilon-aminocaproic acid and tranexamic acid administered in standard dosage, reduce the risk of rebleeding but, as a result of an increased incidence of ischaemic complications, do not benefit patients' outcome.

An experimental study of the influence of antifibrinolytic therapy on post-subarachnoid-hemorrhagic cerebral vasospasm and hydrocephalus

The incidence and severity of cerebral vasospasm and hydrocephalus following induced subarachnoid hemorrhage in an experimental group of animals that subsequently received epsilon-aminocaproic acid was compared to that seen in a control group that received no antifibrinolytic therapy. No augmentation of either vasospasm or hydrocephalus could be attributed to the epsilon-aminocaproic acid in the treated as compared to the control group.

Epsilon amino caproic acid myopathy: additional features

In a patient with a proximal myopathy due to Epsilon Amino Caproic Acid (EACA) bedrest led to marked improvement even before withdrawal of the drug. A biopsy showed a selective necrosis of type I fibers. Plasma level of EACA was low and plasma level of lysine was normal. A 99mTechnetium-MDP showed marked uptake in the affected muscles, whereas a 67Gallium scan was negative.

Monitoring of antifibrinolytic therapy following subarachnoid hemorrhage. The importance of CSF fibrin/fibrinogen degradation products

Ten cases of subarachnoid hemorrhage (SAH) from ruptured cerebral aneurysm are reported. Fibrin/fibrinogen degradation product (FDP) levels were determined simultaneously in blood and cerebrospinal fluid (CSF) at an average frequency of 1.7 days, extended over periods of 8 to 63 days. Successful antifibrinolytic therapy (AFT) correlated with FDP levels in CSF of less than 16 micrograms/ml. Five patients failed to respond to AFT. Levels of FDP in the CSF fluctuated widely in these five patients, and remained at or above 16 micrograms/ml for most of the monitoring period. Blood FDP levels were normal or minimally elevated, and could not be used in predicting or preventing rebleeding episodes. A hypothesis is presented to explain the significance of the presence of FDP's in CSF. In spite of the many techniques employed in monitoring AFT and reviewed in this paper, little information has been gained to improve the results and therapeutic strategies. Among the different methods available, FDP measurements in the CSF have correlated best with rebleeding, and thus may be used in modifying and individualizing therapy. Suggestions are given for future studies.

Pharmacologic management of subarachnoid hemorrhage

Subarachnoid hemorrhage, following rupture of an intracranial aneurysm, affects about 25 000 people in the U.S. each year. Less than half the patients who survive until hospital admission have an overall favorable outcome. This high morbidity and mortality rate is a result of serious complications following the initial subarachnoid hemorrhage, the most significant of these being rebleeding and cerebral ischemia secondary to vasospasm. While surgical clipping of the aneurysm is the most definitive therapy, this procedure may be postponed for a week or two after the initial hemorrhage, depending on the patient's clinical condition. Pharmacological therapy is a critical part of the preoperative care of these patients and of the postoperative management of complications. This article discusses the syndromes of rebleeding and vasospasm and reviews the current pharmacologic therapy for each.

Antifibrinolytic treatment in subarachnoid haemorrhage: present state

Two randomised controlled clinical trials in patients with recently ruptured intracranial aneurysms were undertaken using tranexamic acid (AMCA) to prevent early recurrent bleeding. In our accumulated series of 105 patients 53 were given AMCA and 52 were controls. 13% of the AMCA-treated patients and 31% of the controls rebled. In patients treated with AMCA the recurrent bleeding took place later than the rebleeding in the control patients. Vasospasm and delayed cerebral ischaemic deficits were seen more frequently in patients treated with AMCA. Total mortality from rebleeding and cerebral ischaemia was 25% in AMCA-treated patients and 19% in the controls during the six weeks' observation time. Coagulation factors remained unaffected by the drug. Local fibrinolysis in the cerebrospinal fluid decreased after one week in patients treated with AMCA. After two weeks the fibrinolytic activity was similar in AMCA-treated patients and in the controls. After experimental subarachnoid haemorrhage in 90 rabbits, AMCA was found to suppress plasminogen activator activity, mainly in the leptomeninges. This occurred however only during the first few postbleeding days. Antifibrinolytic agents only appear to reduce the risk of recurrent bleeding during the first ten day period after the primary aneurysm rupture. However they also seem to produce delayed cerebral ischaemia in patients with subarachnoid haemorrhage. Synthetic antifibrinolytics evidently shift the incidence of rebleeding curve to the right but these drugs are probably of diminished value in the subsequent weeks of risk.

Coagulation and fibrinolysis in blood and cerebrospinal fluid after aneurysmal subarachnoid haemorrhage: effect of tranexamic acid (AMCA)

Serial assays of blood coagulation factors as well as of fibrin/fibrinogen degradation products (FDP) and plasminogen activatory activity (PA) on fibrin plates in blood and cerebrospinal fluid (CSF) were performed in 41 consecutive patients with recently ruptured cerebral aneurysms, 21 of whom were randomly treated with tranexamic acid (AMCA). Coagulation factors were unaffected by the drug and plasminogen and FDP decreased in blood after two weeks' treatment. After one week, PA in CSF was increased in control patients and unchanged in AMCA-treated patients, whereas CSF-FDP had decreased among AMCA-treated patients. After two weeks PA as well as FDP in CSF showed the same values in both groups. An increase in CSF-FDP occurred after rebleeding and in patients with cerebral ischaemic symptoms. The results indicate that AMCA inhibits local fibrinolysis in CSF in patients with aneurysm rupture.

A method for monitoring antifibrinolytic therapy in patients with ruptured intracranial aneurysms

A rapid fluorometric assay technique has been utilized to assess the degree of fibrinolytic inhibition in 20 patients with ruptured intracranial aneurysms treated with epsilon-aminocaproic acid (EACA). This method quantitates the available plasminogen activity (APA) of plasma, and has proven to be a reliable means of monitoring antifibrinolytic therapy. Determination of the plasma APA also permits correlation of the level of fibrinolytic activity with putative complications of EACA therapy. Normal control plasma APA was 3.1 +/- 0.7 CTA units/ml, but in patients with subarachnoid hemorrhage (SAH), pretreatment fibrinolytic activity was supranormal at 3.78 +/- 0.88 CTA units/ml. During continuous intravenous administration of EACA (1.5 gm/hr) in patients with SAH, the plasma fibrinolytic activity was decreased to 0.9 +/- 0.31 CTA units/ml. A case described which examplifies the use of this assay. In addition, an approach to monitoring antifibrinolytic therapy using the plasma APA is proposed.

Myoglobinuria following epsilon-aminocaproic acid (EACA) therapy. Case report

Myoglobinuria developed in a patient with subarachnoid hemorrhage treated with a course of 1.43 kg of epsilon-aminocaproic acid (EACA) given over 41 days. Review of eight other cases with a variety of medical disorders shows that this effect occurs after at least 4 weeks of taking doses of a minimum of 24 gm EACA per day. The effect seems to be reversible if discovered early. This side-effect should provide impetus for restricting the duration of EACA therapy to periods under 28 days, in doses no higher than 24 gm/day.

Epsilon-aminocaproic acid and recurrent subarachnoid hemorrhage: a clinical trial

A clinical trial of epsilon-aminocaproic acid (EACA) in preventing recurrent hemorrhage from intracranial arterial aneurysms is reported. Previous reports were reviewed, and their results concerning antifibrinolytic agents were inconclusive in establishing their efficacy. One hundred patients with documented ruptured intracranial aneurysms were admitted to this study within 48 hours of the initial hemorrhage: 45 patients received 36 gm of EACA/day, with 11 documented rebleeds and one suspected rebleed. No benefit was seen from the use of EACA.

Preoperative treatment of ruptured intracranial aneurysms with tranexamic acid and monitoring of fibrinolytic activity

The fibrinolytic activity in cerebrospinal fluid has been monitored by determination of levels of fibrin split products (FSP) in 23 patients with ruptured intracranial aneurysms. In 20 of these 23, FSP was found in the cerebrospinal fluid (CSF), with levels ranging from 10 to 80 micrograms/ml. Eleven of the 23 patients were treated with 2 gm tranexamic acid daily. In these patients FSP was found in only two cases during the 2nd week, while in 12 untreated patients it was found in 10 cases. These results suggest that there exists a localized fibrinolytic activity, and monitoring the FSP levels in the CSF may be a simple and accurate method for controlling the efficiency of antifibrinolytic therapy. Thus, treatment could be begun with a lower dose, which could be increased later as deemed necessary from the results of careful monitoring.

Modern treatment of intracranial aneurysms

The initial physical and neurologic examinations usually allow a presumptive diagnosis of intracranial aneurysm, but confirmation may require computed tomography (CT) and selective angiography. Medical management of the patient necessitates close observation, supportive care, and use of drugs to reduce intracranial pressure and to prevent dissolution of clot at the aneurysmal fundus to prevent rebleeding. The age of the patient may be a deciding factor in selection of surgical candidates. The surgical procedure of choice is direct obliteration of the aneurysm by clipping or ligation, unless such a procedure would compromise the patency of major intracranial vessels or not be possible because of the shape of the aneurysm. With aggressive medical management and modern surgical techniques, many more of these patients may be saved and returned to productive life.

Significance of vasospasm in the treatment of ruptured intracranial aneurysms

The authors have analyzed a total of 96 consecutive cases in which vasospasm followed subarachnoid hemorrhage (SAH). The SAH was caused by ruptured intracranial aneurysm or developed after aneurysm surgery. Usually at least 4 days elapsed between SAH and the onset of vasospasm. Vasospasm subsided an average of 2 weeks after onset. Of 68 patients with preoperative vasospasm, eight died due to cerebral edema resulting from ischemia, and 49% of survivors had neurological deficits. Preoperative vasospasm was not aggravated by surgical intervention when operations were carried out more than 7 days after the onset of vasospasm. Postoperative vasospasm was found in 25 of 52 patients who underwent operation within 1 week after SAH (excluding cases in Grade V). Five of these patients died, all of whom underwent surgery between the fourth and seventh day after SAH (the day of SAH was counted as the first day). There were no deaths among 20 patients operated on within the first 3 days after SAH. Postoperative vasospasm was always mild in these cases, when it occurred, probably because blood clot or blood-stained cerebrospinal fluid was removed by operative procedures. In all cases, 4 to 11 days elapsed between the last SAH and the onset of postoperative vasospasm regardless of the timing of surgery.

Intracranial aneurysms and subarachnoid hemorrhage. A cooperative study. Antifibrinolytic therapy in recent onset subarachnoid hemorrhage

In this cooperative study among 13 institutions, 502 patients were treated with antifibrinolytic medication (epsilon-aminocaproic acid or tranexamic acid) within a 14-day period following rupture of an intracranial aneurysm. Mortality at the end of 14 days was 11.6%; proved rebleed rate was 12.7%. Patients with an internal carotid or anterior cerebral aneurysm had the highest mortality and rebleed rate. Most rebleeds occurred between the sixth and eleventh days following the initial bleed. Significantly higher mortality was reported among patients with cerebral vasospasm, yet rebleed rate was no different among those patients with or without vasospasm. The same pattern was observed among patients with a mean blood pressure value above and below 110 mm Hg. We conclude that antifibrinolytic therapy provides beneficial treatment to patients with recent onset subarachnoid hemorrhage (SAH) following rupture of an intracranial aneurysm.