The treatment of chronic subdural hematoma (cSDH) is still charged of significant risk of hematoma recurrence. Patient-related predictors and the surgical procedures themselves have been addressed in many studies. In contrast, postoperative management has infrequently been subjected to detailed analysis. Moreover variable intravenous fluid administration (IFA) was not reported in literature till now in the context of cSDH treatment.
A total of 45 patients with cSDH were operated in our department via two burr hole craniostomy within one calendar year. Downward drainage was routinely left in hematoma cavity for a one day. Independent variables selected for the analysis were related to various aspects of patient management, including IFA. Two dependent variables were chosen as measure of clinical course: the rate of hematoma recurrence (RHR) and neurological status at discharge from hospital expressed in points of Glasgow Outcome Scale (GOS). Univariate and multivariate regression analyses were performed. Hematoma recurrence with subsequent evacuation occurred in 7 (15%) patients.
Univariate regression analysis revealed that length of IFA after surgery influenced both dependent variables: RHR (p = 0.045) and GOS (p = 0.023). Multivariate regression performed by backward elimination method confirmed that IFA is a sole independent factor influencing RHR. Post hoc dichotomous division of patients revealed that those receiving at least 2000 ml/day over 3 day period revealed lower RHR than the group with less intensive IFA. (p = 0.031).
IFA has been found to be a sole factor influencing both: RHR and GOS. Based on those results we may recommend administration of at least 2000 ml per 3 days post-operatively to decrease the risk of hematoma recurrence.
Citation: Janowski M, Kunert P (2012) Intravenous Fluid Administration May Improve Post-Operative Course of Patients with Chronic Subdural Hematoma: A Retrospective Study. PLoS ONE 7(4): e35634. doi:10.1371/journal.pone.0035634
Editor: Isaac Yang, University of California Los Angeles, United States of America
Received: July 17, 2011; Accepted: March 20, 2012; Published: April 20, 2012
Copyright: © 2012 Janowski, Kunert. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Funding: No external funding was received for this study.
Competing interests: The authors have declared that no competing interests exist.
Nowadays the diagnosis of chronic subdural hematoma (cSDH), in general, conveys favourable prognosis . It results from relatively high success rate of surgical treatment. Despite that cSDH evacuation is charged of significant risk of hematoma recurrence . Thus the treatment of cSDH still attracts attention of clinical researchers. It was evinced by controlled randomized trial published recently in Lancet . The benefit of drain placement following cSDH evacuation has been proven by this study. In our department, like in North America , such practice was established long ago without previous evidence-based data.
Independent predictors of cSDH recurrence have been identified in several articles. However they mostly consist of non-modifiable factors such as hematoma characteristics and co-morbidities , , , . They are valuable for counselling patients and their families but are of less importance for the modification of treatment process. Other set of articles recently pointed at the two burr hole craniostomy as a procedure of choice for cSDH evacuation, by this way authorizing surgical approach used in our department for years , , , , , .
In contrast to patient-related factors and the surgical procedure itself, the management of patients following surgery for cSDH has been infrequently subjected to detailed analysis. However it can be an important factor warranting further progress in improvement of treatment results. Since, to the best of our knowledge, the influence of intensity of intravenous fluid administration during post-operative period on clinical course of patients operated due to cSDH was not evaluated till now, we included it into analysis.
The evaluation of factors influencing outcomes in patients with cSDH treated surgically including those related to the post-operative care such as intravenous fluid administration (IFA).
A total of 45 patients with cSDH were operated in our department via burr-hole craniostomy within one calendar year. Patients' age ranged from 24 to 86 (mean 66) yrs. The ratio of men to women was 2:1. On admission patients were in good neurological condition −13–15 pts GCS. Hemiparesis did not exceed 4 pts Lovett scale. Bilateral haematomas were present in 3 (7%) patients. Abnormal coagulation profile was diagnosed in another 6 (14%) patients – they were operated only after profile correction. Hematocrit and Natrium values of all patients were within normal range (39–50% and 136–143 mmol/l, respectively).
Description of procedures
Patients with cSDH were routinely operated in our department as emergency cases, without any delay. The surgeries were performed under general anaesthesia, however since it is very short, the kind of anaesthesia should not influence the fluid intake by patients in the post-operative period. Downward drainage was left in hematoma cavity for a one day. Drainage placement was abandoned in one patient only, because of intra-operative brain re-expansion.
The intravenous fluid therapy consisted of crystalloids. Fluids were infused slowly, at a rate of 125 ml/h. Between drips patients were mobilized. Beside intravenous fluid administration patients had free access to food and drink. Patients were kept in hospital until surgical wound got healed. Usually it was 7 days following surgery and 10 days after re-operation. Head CT scan and evaluation of neurological status were performed in all patients at discharge from hospital.
Independent variables (factors) selected for the analysis were related to various aspects of therapy (Table 1). Two dependent variables were chosen as a measure of clinical course: the rate of hematoma recurrence (RHR) and neurological status at discharge from hospital expressed in points of Glasgow Outcome Scale (GOS). Then both: independent and dependent variables were subjected to correlation analyses using Pearson correlation coefficients (PROC CORR, SAS, version 9.2) to exclude redundancy.
Table 1. Description of independent variables selected for regression analysis.doi:10.1371/journal.pone.0035634.t001
Univariate and multivariate regression analysis has been performed using maximum likelihood (ML) approach (PROC LOGISTIC, SAS, version 9.2). If quasi-complete separation of data points were detected, Firth penalized maximum likelihood (FPML) method has been employed. Likelihood ratio (LR) has been used for testing global null hypothesis, with significance level set at 0.05. Backward selection process during multivariate regression analysis has been performed manually as current version of SAS does still not support Firth bias correction method. Prior to backward selection initiation the results of independent variable correlation has been analysed in detail to exclude similar and highly interdependent factors disturbing the process of multivariate regression.
Significant influence of IFA on clinical course of patients has been found. It warranted supplementary analysis of this factor. The volume of ca. 2000 ml/day is considered as a daily water demand thus the number of postoperative days when fluids were administered in at least such amount has been added to the analysis and named as full fluids (FF). It enables to shape the easy to memorize for clinicians “take home message", beyond the rather difficult to apply in daily practice, results of multivariate regression analysis. Finally patients were divided into two groups with regard to FF length: one with administration of at least 2000 ml/day over at least 3 postoperative days (high-dose fluid administration, HDFA) and the other with administration of at least 2000 ml/day for a period shorter than 3 days postoperatively (low-dose fluid administration, LDFA).
Since this is retrospective analysis of conventionally treated patients, without disclosure of their identity, no ethics approval from Institutional Review Board was necessary. The amount of intravenous fluids administered to patients depended on preference of physician taking care in post-operative period. Some physicians routinely withdrew drips within 1–2 days, while others routinely kept them over several days. Such situation takes place as no medical standard regarding the post-operative fluid therapy for patients with cSDH was set yet. Informed consent for surgery was obtained from each patient. Since it is not prospective study no consent for inclusion into the study was possible to receive at all. In fact, retrospective analysis of treatment results in many neurosurgical conditions is a part of clinical duties in our department, and only outstanding findings are prepared for publication.
Hematoma recurrence with subsequent evacuation occurred in 7 (15%) patients. At discharge from hospital 42 patients experienced good recovery (5 pts GOS). Moderate disability (4 pts GOS) was observed in remained 3 patients due to residual neurological deficit which was present preoperatively. Hematoma recurrence did not worse an outcome. All patients subjected to re-operation recovered satisfactorily. No complication of general anaesthesia and severe medical consequences during postoperative period were observed.
No correlation between dependent variables has been found (phi = −0.11, p = 0.45). The interdependence of independent variables has been revealed in several cases only (Table S1). Based on that Markwalder scale has been excluded from backward multivariate regression due to high correlation with other more detailed indicators of neurological status on admission to hospital.
Univariate regression analysis revealed that length of IFA after surgery influenced both dependent variables: RHR (p = 0.045) and GOS (p = 0.023) (Table 2). The reduction of period of post-operative IFA increased the risk of hematoma recurrence and was related to worse outcome at discharge from hospital. No one of other independent variables such as: age, gender, neurological status on admission to hospital, laboratory exams, hematoma characteristic and the level of surgeon competence influenced the rate of hematoma recurrence. Patient outcome (GOS) has not also been affected by above factors except of Natrium level in serum.
Table 2. Univariate regression analysis.doi:10.1371/journal.pone.0035634.t002
Multivariate regression performed by backward elimination method confirmed that IFA is a sole independent factor influencing RHR (Table 3). GOS has been affected by a combination of 2 factors: IFA and Na (Table 4).
Table 3. Multivariate regression analysis: summary of backward independent variable elimination process for dependent variable RHR.doi:10.1371/journal.pone.0035634.t003
Table 4. Multivariate regression analysis: summary of backward independent variable elimination process for dependent variable GOS.doi:10.1371/journal.pone.0035634.t004
Supplementary analysis revealed that FF is also significant predictor of RHR (p = 0.036). Dichotomous division of patients with relation to FF revealed that HDFA group experienced lower rate of hematoma recurrence than LDFA one (p = 0.031) (Table 5).
We report on the regression analysis of cSDH treatment. Relatively homogenous group of patients was presented in this study with regard to good neurological status on admission to hospital. It probably determined favourable outcome at discharge. Despite that the rate of hematoma recurrence was significant.
The major finding of this study was a positive influence of intravenous fluid administration during post-operative period on the clinical course of patients with cSDH. The role of appropriate hydration of patients following more complex diseases such as subarachnoid haemorrhage is well recognized . However this issue was not raised in literature in the context of cSDH which is simpler entity, but appropriate fluid delivery may facilitate brain re-expansion thus avoiding hematoma recurrence and accelerating patient recovery.
As fluid therapy can not be continued endlessly the direct inference from multivariate regression analysis is rather impractical. Thus we divided patients post hoc into 2 groups with regard to intensity of fluid therapy. Based on those results we feel to be entitled to recommend administration of at least 2000 ml per 3 days post-operatively to decrease the risk of hematoma recurrence.
Additionally, in our opinion fluid therapy should be included in forthcoming investigations focused on cSDH treatment. The application of technical advances such as pulse dye densitometry for monitoring of fluid therapy may contribute to set a closer link between patient hydration status and the clinical course in this disorder . Data accumulation might bring stronger argument and further refinements of fluid therapy, by this way give reasons for controlled randomized trial initiation to establish an evidence–based data to improve further the management of patients with cSDH.
Post-operative period in patients with cSDH has been infrequently addressed by clinical researchers. Only recently it was shown that bed rest in horizontal position following surgery positively influenced clinical course . In other study head elevation by 30 degrees did not worse outcome and recurrence rate in comparison to above strict regime . Theoretically, bed rest may be efficient by facilitation of brain re-expansion. Opposite approach emphasized the value of patient early mobilization post-operatively . It decreased medical complications while not increasing the rate of hematoma recurrence. Our approach based on intensive fluid therapy not only may stimulate brain re-expansion but also enables early mobilization of patients between drips. By this way intravenous fluid administration may constitute a golden mean giving an advantage of bed rest and early mobilization at the same time.
The other finding of this study was that higher values of Natrium in serum of patients on admission to hospital was related to worse outcome at discharge from hospital. However on the basis of this study it is difficult to explain the reason for that, especially as the levels of Natrium were within normal range. Till now the results of laboratory examinations were not included into analyses of cSDH treatment and if this factor is to be considered in future investigations it may also shed more light on the significance of Natrium level for therapy of patients with cSDH.
The influence of level of surgeon competence might be embarrassing and it is rarely subjected to analysis. As burr hole craniostomy is frequently the first surgical procedure on the long route to neurosurgical mastership it is important to evaluate whether such training scheme does not harm patients. Patients included in this study were operated by 12 various physicians (5 specialists and 7 trainees). Neither influence of particular physician (data not shown) nor its level of competence (specialist vs trainee, p>0.05) on the clinical course of patients with cSDH has been shown. One published series of cSDH treatment by residents was also comparable to other major series reported in literature . Thus there is no advantage of specialist hand virtuosity and patients may equally benefit from trainee craft. Obviously each surgery was supervised by an attending neurosurgeon.
However we are aware that conclusions drawn from this study are limited due to some weaknesses such as retrospective approach, relatively small group of patients, no information on loculations, CT-imaged density and co-morbidities etc., we believe that this work is worth to be published as new aspect of cSDH treatment has been shown.
We hypothesize that post-operative care might be a source of further improvement of cSDH therapy and it requires more attention from researchers. Appropriate fluid administration and Natrium level may prevent hematoma recurrence and accelerate patient recovery.
Correlation analysis of independent variables.
The authors express their appreciation to Prof. Andrzej Marchel, Head of the Department of Neurosurgery, Medical University of Warsaw, Poland, for critical review of the manuscript.
Conceived and designed the experiments: MJ PK. Performed the experiments: MJ PK. Analyzed the data: MJ. Contributed reagents/materials/analysis tools: MJ PK. Wrote the paper: MJ PK.
- 1. Weigel R, Schmiedek P, Krauss JK (2003) Outcome of contemporary surgery for chronic subdural haematoma: evidence based review. J Neurol Neurosurg Psychiatry 74: 937–943.
- 2. Horn EM, Feiz-Erfan I, Bristol RE, Spetzler RF, Harrington TR (2006) Bedside twist drill craniostomy for chronic subdural hematoma: a comparative study. Surg Neurol 65: 150–153. discussion 153–154.
- 3. Santarius T, Lawton R, Kirkpatrick PJ, Hutchinson PJ (2008) The management of primary chronic subdural haematoma: a questionnaire survey of practice in the United Kingdom and the Republic of Ireland. Br J Neurosurg 22: 529–534.
- 4. Komotar RJ, Starke RM, Connolly ES (2010) The role of drain placement following chronic subdural hematoma evacuation. Neurosurgery 66: N15–16.
- 5. Torihashi K, Sadamasa N, Yoshida K, Narumi O, Chin M, et al. (2008) Independent predictors for recurrence of chronic subdural hematoma: a review of 343 consecutive surgical cases. Neurosurgery 63: 1125–1129. discussion 1129.
- 6. Yamamoto H, Hirashima Y, Hamada H, Hayashi N, Origasa H, et al. (2003) Independent predictors of recurrence of chronic subdural hematoma: results of multivariate analysis performed using a logistic regression model. J Neurosurg 98: 1217–1221.
- 7. Stanisic M, Lund-Johansen M, Mahesparan R (2005) Treatment of chronic subdural hematoma by burr-hole craniostomy in adults: influence of some factors on postoperative recurrence. Acta Neurochir (Wien) 147: 1249–1256. discussion 1256–1247.
- 8. Ko BS, Lee JK, Seo BR, Moon SJ, Kim JH, et al. (2008) Clinical analysis of risk factors related to recurrent chronic subdural hematoma. J Korean Neurosurg Soc 43: 11–15.
- 9. Mondorf Y, Abu-Owaimer M, Gaab MR, Oertel JM (2009) Chronic subdural hematoma–craniotomy versus burr hole trepanation. Br J Neurosurg 23: 612–616.
- 10. Lega BC, Danish SF, Malhotra NR, Sonnad SS, Stein SC (2009) Choosing the best operation for chronic subdural hematoma: a decision analysis. J Neurosurg.
- 11. Lee JY, Ebel H, Ernestus RI, Klug N (2004) Various surgical treatments of chronic subdural hematoma and outcome in 172 patients: is membranectomy necessary? Surg Neurol 61: 523–527. discussion 527–528.
- 12. Han HJ, Park CW, Kim EY, Yoo CJ, Kim YB, et al. (2009) One vs. Two Burr Hole Craniostomy in Surgical Treatment of Chronic Subdural Hematoma. J Korean Neurosurg Soc 46: 87–92.
- 13. Moskala M, Goscinski I, Kaluza J, Polak J, Krupa M, et al. (2007) Morphological aspects of the traumatic chronic subdural hematoma capsule: SEM studies. Microsc Microanal 13: 211–219.
- 14. Taussky P, Fandino J, Landolt H (2008) Number of burr holes as independent predictor of postoperative recurrence in chronic subdural haematoma. Br J Neurosurg 22: 279–282.
- 15. Hoff R, Rinkel G, Verweij B, Algra A, Kalkman C (2009) Blood volume measurement to guide fluid therapy after aneurysmal subarachnoid hemorrhage: a prospective controlled study. Stroke 40: 2575–2577.
- 16. Kasuya H, Onda H, Yoneyama T, Sasaki T, Hori T (2003) Bedside monitoring of circulating blood volume after subarachnoid hemorrhage. Stroke 34: 956–960.
- 17. Abouzari M, Rashidi A, Rezaii J, Esfandiari K, Asadollahi M, et al. (2007) The role of postoperative patient posture in the recurrence of traumatic chronic subdural hematoma after burr-hole surgery. Neurosurgery 61: 794–797. discussion 797.
- 18. Ishfaq A, Ahmed I, Bhatti SH (2009) Effect of head positioning on outcome after burr hole craniostomy for chronic subdural haematoma. J Coll Physicians Surg Pak 19: 492–495.
- 19. Kurabe S, Ozawa T, Watanabe T, Aiba T (2010) Efficacy and safety of postoperative early mobilization for chronic subdural hematoma in elderly patients. Acta Neurochir (Wien).
- 20. Gastone P, Fabrizia C, Homere M, Francesco C, Alberto M, et al. (2004) Chronic subdural hematoma: results of a homogeneous series of 159 patients operated on by residents. Neurol India 52: 475–477.