(Stroke. 2001;32:1176.)
© 2001 American Heart Association, Inc.
Original Contributions |
Incidence and Significance of Early Aneurysmal Rebleeding Before Neurosurgical or Neurological Management
From the Department of Neurosurgery, Hirosaki University School of Medicine, Hirosaki, Japan.
Correspondence to Hiroki Ohkuma, MD, Department of Neurosurgery, Hirosaki University School of Medicine, 5 Zaifu-cho, Hirosaki, 036-8216 Japan. E-mail ohkuma{at}cc.hirosaki-u.ac.jp
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Abstract |
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Background and Purpose—Rebleeding is a major cause of death and disability in aneurysmal subarachnoid hemorrhage (SAH); however, there has been no report focusing on rebleeding before hospitalization in neurosurgical or neurological institutions. The aim of this study was to clarify the incidence of prehospitalization rebleeding, its impact on the clinical course and prognosis in patients with aneurysmal SAH, and the possible factors inducing it.
Methods—In 273 patients who were admitted to our institution within 24 hours after the initial SAH bleeding and whose clinical course before admission could be fully evaluated, the patients’ clinical conditions and CT findings on admission, operability, prognosis, and possible factors inducing rebleeding were comparatively evaluated between the patients with and without an episode of prehospitalization rebleeding.
Results—Of the 273 patients, 37 (13.6%) patients suffered from 39 episodes of rebleeding in the ambulance or at the referring hospital before admission to our hospital. The peak time of rebleeding was within 2 hours (77%), in which the incidence was statistically significant compared with that occurring 2 to 8 hours after the initial SAH bleeding (P<0.01). The group experiencing rebleeding showed more severe Hunt and Hess grades on admission, higher rates of intracerebral hematoma, of intraventricular hematoma, and of subdural hematoma on CT scan on admission, less operability, and poorer prognoses with statistically significant differences compared with the group that did not experience rebleeding. Systolic arterial pressure >160 mm Hg was a possible risk factor of rebleeding (odds ratio 3.1, 95% CI 1.5 to 6.8).
Conclusions—Rebleeding during transfer and at the referring hospital is not rare. To improve overall outcome of aneurysmal SAH, the results obtained in this study should be made available to general practitioners and the doctors devoted to emergency medicine.
Key Words: cerebral aneurysm • emergency medical services • subarachnoid hemorrhage
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Introduction |
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TopAbstractIntroductionSubjects and MethodsResultsDiscussionReferences |
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There have been many reports investigating aneurysmal rebleeding, because it is a major cause of death and disability in aneurysmal subarachnoid hemorrhage (SAH)1 2 3 in addition to the primary bleeding and delayed ischemic deterioration.4 The cumulative incidence of aneurysmal rebleeding within the first 2 weeks has been estimated to be from 9% to 23%,3 5 6 7 8 and the mortality due to rebleeding has been reported to range between 50% and 80%.2 6 9 10 11 12 These findings were obtained by the studies investigating the rebleeding that occurs after admission to neurological or neurosurgical institutions. Rebleeding before admission to neurological or neurosurgical institutions (prehospitalization rebleeding) might also contribute to mortality13 ; however, its incidence and clinical importance are unknown, inasmuch as there has been no report focusing on it.
Regarding the time distribution of rebleeding, recent reports have indicated that the peak interval for rebleeding is in the early state of SAH.3 5 11 14 Furthermore, some reports have shown that the most vulnerable period for rebleeding is during the ultra-early stage of SAH, such as within a several hours10 15 or 6 hours16 after the initial bleeding. Although these reports have investigated rebleeding that occurred after hospitalization in neurosurgical or neurological institutions, their results suggest that the period before admission to neurological or neurosurgical institutions, such as during transfer and at the referring hospital, is also a vulnerable period for rebleeding. In addition, the patients’ emotional and physical conditions are usually unstable during transfer, which might promote the risk of rebleeding.
The aim of the present study was to clarify the incidence of prehospitalization rebleeding, its impact on the clinical course and prognosis in the patients with aneurysmal SAH, and the possible factors inducing the rebleeding during the period before admission.
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Subjects and Methods |
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TopAbstractIntroductionSubjects and MethodsResultsDiscussionReferences |
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During a period of 10 years, from January 1989 to December 1998, 376 consecutive patients with aneurysmal SAH were treated in our institution. Of these cases, 273 patients who were admitted to our institution within 24 hours after the initial bleeding and whose clinical course before admission could be fully evaluated by the medical records of their ambulance transfer and at the referring hospitals were prospectively selected for the present study. Regarding the referral pattern, of the 273 patients, 78 patients were directly transferred to our institution by ambulance, 8 patients came directly to our institution by themselves without using an ambulance, and 187 patients were transferred by ambulance via the regional referring hospitals. Unusual sudden headache with loss of consciousness or sudden deterioration of consciousness level occurring within 24 hours after the initial SAH and before admission to our institution were considered evidence of early prehospitalization rebleeding, after other causes, such as epileptic seizure from the clinical course, were excluded.6 11 12 If rebleeding occurred after the initial CT scan was performed in the referring hospitals, the CT scan taken immediately after admission to our institution was compared with the initial CT scan, and rebleeding was confirmed. If rebleeding occurred before the CT scan was performed, the rebleeding was judged by 3 observers in an independent manner on the basis of the clinical course described above, and rebleeding was determined when complete agreement among the 3 observers was achieved. The hourly rebleeding rate before admission to our hospital was calculated by clinical life table techniques modified to adjust for intervals to admission, which were expressed by the percentage ratio of the number of the episodes of rebleeding occurring each hour after the initial SAH to the number of patients who were not admitted to our institution and had the possibility of prehospitalization rebleeding in the corresponding hour.
Other than these 273 patients, 18 patients with poor clinical condition were referred to us from the regional hospitals during the same period; however, they were not transferred to our institution because their clinical condition did not allow aneurysm surgery. In 5 of the 18 (27.8%) patients, rebleeding was thought to play a causative role in their poor clinical condition. However, these 18 cases were not included in the present study because their clinical course and prognosis could not be evaluated in an identical manner.
Between the patients with early prehospitalization
rebleeding (the rebleed group) and those without early
prehospitalization rebleeding (the non-rebleed group), several clinical
factors and the impact of rebleeding on their clinical course and
prognosis were comparatively evaluated. The conditions of patients on
admission to our institution were evaluated by using the Hunt and Hess
clinical grading scale. The findings of CT scan performed on admission
to our hospital were evaluated in terms of the degree of SAH and
accompanying hemorrhagic findings, such as
intracerebral hematoma (ICH),
intraventricular hematoma (IVH), or subdural
hematoma (SDH). The degrees of SAH on CT scan were divided into 2
groups: (1) none to moderate SAH, which corresponds to Fisher group 0
to 2, and (2) marked SAH, which corresponds to Fisher group 3. Most of
the patients underwent aneurysm surgery within 24 hours after
admission except the patients whose neurological or general conditions
did not allow early operation. Prognosis was evaluated at 3 months
after the ictus by use of the Glasgow Outcome Scale. Differences
between the rebleed group and the non-rebleed group were assessed by
the 
2 test, Mann-Whitney
U test, or Student
t test. Significance was
assigned at
P<0.05.
As possible factors inducing early rebleeding, arterial blood pressure and hemostatic parameters were evaluated. Hemostatic parameters, such as prothrombin time, activated partial thromboplastin time, platelet count, and bleeding time, were examined on admission to our institution, and the results of the rebleed and non-rebleed groups were compared by use of the Mann-Whitney test. In the rebleed group, to evaluate the possible role of arterial blood pressure as a factor contributing to rebleeding, the values of systolic arterial blood pressure measured in the ambulance or at the referring hospital within 20 minutes before rebleeding were used for comparison. In the non-rebleed group, of the values of systolic arterial blood pressure measured during transfer, the maximum value for each patient was selected for comparison. The values of systolic arterial blood pressures in each group were compared by use of the Mann-Whitney test, and the possible contribution of elevated arterial blood pressure to rebleeding at various cutoff points was examined by odds ratios (ORs) and their 95% CIs. ORs and their 95% CIs were calculated by logistic regression analysis.
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Results |
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TopAbstractIntroductionSubjects and MethodsResultsDiscussionReferences |
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The distribution of 273 patients in the intervals between the initial SAH and admission to our institution is shown in Figure 1
. Of the 273 patients, 136 (50%) patients
were admitted within 2 hours, and 206 (75%) patients were admitted
within 6 hours after the initial bleeding.
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Of the 273 patients, 37 (13.6%) patients suffered from 39 episodes of rebleeding within 24 hours after the initial SAH before admission to our institution. Thirty-five patients suffered from a single episode of rebleeding, and 2 patients had 2 episodes of rebleeding. Twelve episodes of rebleeding (30.8%) occurred in the ambulance car, and 27 episodes (69.2%) occurred at the regional referring hospitals. Twenty-two episodes of rebleeding occurred before the diagnosis of SAH was confirmed by CT scan, and 17 episodes occurred after the CT scan was performed and the diagnosis of SAH was obtained.
The distribution of the patients with early
prehospitalization rebleeding in intervals between the initial SAH and
rebleeding is shown in
Figure 2. Thirty episodes (77%) occurred within 2
hours, and 36 episodes (92%) occurred within 6 hours after the initial
SAH.
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The hourly rate of rebleeding, which was expressed by
calculating the percentage ratio of the number of the episodes of
rebleeding in each interval to the number of patients who were not
admitted to our institution in the corresponding interval, is shown in
Table 1. The incidences from 0 to 1 hour and from 1 to
2 hours were statistically higher than those from 2 to 8 hours
(P<0.01).
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Clinical factors were compared between 37 patients with
early prehospitalization rebleeding and 236 patients without early
prehospitalization rebleeding
(Table 2). No statistically significant differences in
age, sex, and site of aneurysms were seen between the 2 groups.
In CT findings on admission, the rate of marked SAH was higher in the
rebleed group compared with non-rebleed group, without a statistically
significant difference. Accompanying findings such as ICH, IVH, and SDH
were statistically higher in the rebleed group
(P=0.0007,
P=0.0034, and
P=0.0323, respectively). The
Hunt and Hess grade on admission indicated that a severe grade was
statistically more dominant in the rebleed group
(P<0.0001). Operability was
statistically less in the patients with rebleeding
(P=0.0059). Of the 14 patients
who did not undergo aneurysm surgery in the rebleed group,
rebleeding directly contributed to inoperability in 9 patients.
Prognosis evaluated by the Glasgow Outcome Scale showed that poor
prognosis was statistically dominant in the rebleed group
(P<0.0001). Of the 19 deaths
in the rebleed group, rebleeding contributed to death as a direct cause
in 12 patients.
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The mean±SD values of the hemostatic parameters prothrombin time, activated partial thromboplastin time, platelet count, and bleeding time in the rebleed group were 11.7±0.2 seconds, 26.2±0.5 seconds, 21.2±2.4x104/mm3, and 2.2±0.3 minutes, respectively. Those values in the non-rebleed group were 11.9±0.2 seconds, 25.9±0.4 seconds, 19.8±3.0x104/mm3, and 2.1±0.2 minutes, respectively. There were no statistically significant differences in any of the parameters between the 2 groups.
The mean±SD value of systolic arterial
blood pressure in the rebleed group, which was measured within 20
minutes before rebleeding, was 172.4±33.9 mm Hg. The mean±SD
value of the maximum value of systolic arterial
blood pressure during transfer in the non-rebleed group was
153.2±24.2 mm Hg. The former was statistically significantly
higher than the latter
(P<0.0001, Mann-Whitney
U test). The distribution of
the values of systolic arterial blood pressure in
the rebleed group and in the non-rebleed group were compared at various
cutoff points
(Table 3). The results indicated that systolic
arterial pressure >160 mm Hg was a risk factor
contributing to rebleeding.
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Discussion |
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TopAbstractIntroductionSubjects and MethodsResultsDiscussionReferences |
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Although there have been no reports focusing on rebleeding before admission to neurosurgical or neurological institutions, some reports have mentioned it in addition to in-hospital rebleeding. Hillman et al17 reported that in 121 patients with aneurysmal SAH, rebleeding occurred before admission in 4 (3.3%) of the 11 patients with early rebleeding within 24 hours after the initial SAH. Inagawa et al16 reported that in 418 patients with aneurysmal SAH admitted within 6 hours after the initial bleeding, rebleeding occurred before admission in 18 (4.3%) of the 61 patients with ultra-early rebleeding. Our prospective study focused on prehospitalization rebleeding, which occurred in 13.6% of the patients, suggesting that prehospitalization rebleeding might occur more frequently than expected. Furthermore, many patients might die before admission because of rebleeding.13 15 Of the 18 patients with poor clinical condition who were not transferred to our institution and were not included in the present study, rebleeding was thought to be a causative factor for their poor clinical condition in 5 (27.8%) patients.
Regarding the timing of rebleeding, previous reports investigating daily changes of the rate of rebleeding after hospitalization in neurosurgical or neurological units have not shown consistent results. Kassell and Torner5 reported that the peak time of rebleeding occurred on the same day as the initial hemorrhage and that there was no later peak. Several reports3 11 14 have indicated the same tendency. However, there have been several reports showing contrary results in which the peak of rebleeding was not on the day of the original hemorrhage but at the end of the first week and the beginning of the second week6 9 18 19 or the fourth week7 or in which there was no peak.8
On the other hand, recent reports focusing on hourly changes of the rate of rebleeding after hospitalization within 24 hours of the initial hemorrhage have indicated more consistent results. The peak was within 2 hours,10 3 hours,15 or 6 hours,16 suggesting that rebleeding occurs more frequently in the earlier period after the initial SAH. The studies investigating the daily rate of rebleeding could not reach consistent results most probably because the rates of the patients admitted within 24 hours after the initial hemorrhage were lower in those studies20 that missed the rebleeding occurring in the ultra-early period after the initial SAH, such as within 6 hours. In addition, in some reports, the patients who died during the first day were excluded from the evaluation,18 or deterioration within the first day was not recorded as rebleeding.19 The results of the present study investigating prehospitalization rebleeding also indicated that the patients were more susceptible to rebleeding in the earlier period after the initial SAH. These results can be explained by the findings that the fibrin net covering the rupture point of aneurysm is so friable in the early phase of clotting that it cannot tolerate even a slight difference between the internal and external pressure of the aneurysm.15 21
Most reports investigating posthospitalization rebleeding have shown that rebleeding seriously affects the prognosis. The present study revealed that prehospitalization rebleeding also seriously affected the patient’s clinical condition on admission and prognosis. In the rebleed group, the Hunt and Hess grades on admission were higher, which resulted in high inoperability and poor prognosis. CT scan on admission showed that ICH, IVH, and SDH were statistically increased by rebleeding, as previous reports have indicated.22 23 However, the degree of SAH itself was not statistically enhanced by rebleeding, which can be explained by the reports indicating that adhesion of an aneurysm with surrounding structures such as brain or arachnoid, which was caused by the initial bleeding, causes the blood to expand into the brain parenchyma or subdural space when rebleeding occurs.24 25
These results show that the prehospitalization period is a vulnerable period for rebleeding and that prehospitalization rebleeding seriously affects the patient’s prognosis, leading us to recognize that to improve the overall outcome of SAH patients, the prevention of prehospitalization rebleeding is essential. In the present report, hemostatic parameters and arterial blood pressures were examined as possible factors contributing to rebleeding. Hemostatic parameters showed no statistically significant differences between the rebleed and non-rebleed groups. Reduced platelet functions, which were measured before rebleeding, have been thought to contribute to in-hospital rebleeding.10 26 In the present study, hemostatic parameters were measured on admission to our institute; therefore, the values before rebleeding were unknown, which might account for the difference in results from previous reports.10 26 Regarding arterial blood pressure, systolic arterial blood pressure measured within 20 minutes before rebleeding in the rebleed group was compared with the maximum value of systolic arterial blood pressure measured during transfer in the non-rebleed group, because it was impossible to compare arterial blood pressure in the 2 groups measured at the same situation. Systolic arterial blood pressure was statistically higher in the rebleed group than the non-rebleed group. Especially, systolic arterial blood pressure >160 mm Hg appears to be a risk factor for early prehospitalization rebleeding. Some reports have indicated that no statistically significant difference of systolic arterial blood pressure was seen between the patients with and without rebleeding after hospitalization.10 16 However, this may be attributable to the fact that pharmacologically induced systemic arterial hypotension is usually routinely performed in neurological or neurosurgical units5 and that those reports focusing on in-hospital rebleeding have missed the changes in the ultra-early phase of SAH. In the ultra-early phase of SAH, the fibrin net on the rupture point of aneurysm is so fragile that it might be more easily broken by the changes of arterial blood pressure.15 Therefore, induced arterial hypotension seems essential for preventing rebleeding in the ultra-early phase of SAH.
To improve the overall outcome of aneurysmal SAH patients, the results obtained in the present study should be made available not only to neurologists and neurosurgeons but also to general practitioners and the doctors devoted to emergency medicine.
Received August 20, 2000; revision received November 6, 2000; accepted December 10, 2000.
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