3.9 Time to Acute Subdural Hematoma Evacuation

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Description of Indicator

Relationship to Quality Medical care should be timely
Type of Indicator Hospital process, Hospital level
Proposed Data Source EMS Records, Trauma Registry
Definition Time from onset of injury to acute subdural hematoma (ASDH) evacuation*‡
Numerator Time of ASDH evacuation‡ for patients age 18 years and older diagnosed with an ASDH AND who undergo surgical treatment† - time of injury*β
Denominator Not applicable
Benchmark Not applicable
Risk Adjustment Geographic area (urban, rural), initial GCS, mechanism of injury, type of injuries

* Time of injury may not be precisely known, but can likely be accurately estimated. We believe that using time of injury as a starting point for a time based measure of ASDH evacuation is conceptually attractive from both a physiological and quality improvement perspective as it represents the onset of tissue injury. It is analogous to using time of symptom onset in patients with stroke or myocardial infarction.
‡ Time of ASDH evacuation = Time of skin incision for the procedure.
† The indicator inclusion criteria are patients who are diagnosed with an ASDH (< 48 hours from time of injury) and undergo evacuation. Evacuation may not be offered to all patients with an ASDH depending on perceived potential for therapeutic benefit.
ß Time to ASDH Evacuation will be reported as an interval measure (mean or median) with a measure of variation (standard deviation or interquartile range).


This indicator is intended to monitor the timeliness of treatment of patients with an ASDH. The data recorded from indicator #2.1 (Time to First Medical Contact), indicator #2.7 (Time to Definitive Trauma Care) and indicator #3.9 (Time to Acute Subdural Hematoma Evacuation) may provide opportunities for calculating other metrics that can inform trauma system performance.


Panel Review
Panelists specified the purpose of this indicator was to identify whether a trauma program had a dedicated neurosurgical trauma team and whether it functioned efficiently. It was noted that the Brain Trauma Foundation provides an excellent synthesis of evidence based practices for traumatic brain injury and that consideration should be given to using the Foundation’s guidelines as a basis for additional quality indicator development60.
Panelists reported that the indicator was important as it captured the necessity of timely access to neurosurgery, but had concerns that there is currently no expectation of an acceptable time to evacuation. Panelists debated whether adjustment for ASDH severity (e.g. size, mass effect, midline shift) would be helpful, but decided that if decision is made to evacuate an ASDH (panelists noted that not all ASDH require evacuation), it should be done in a timely fashion. Panelists noted that while the indicator addresses timeliness, it does not address the appropriateness of the surgery.


Trauma Center Review
The trauma centers highlighted the challenges of measuring quality ASDH care, which can consist of both surgical and non-surgical interventions. Centers suggested that differentiation between appropriate and inappropriate surgical intervention could be a helpful measure.
The trauma centers had concerns regarding using time of injury as the reference point for the indicator. They noted that it is difficult to accurately and consistently ascertain time of injury and suggested that time of EMS arrival may be more suitable. In addition they noted that factors such as inappropriate triage, geographic area and limited resources may influence the results of this indicator for some trauma centers.


Review of Literature & Evidence
Face Validity: No studies identified.
Construct Validity: Four studies showed that timing from injury to evacuation of an ASDH was not associated with decreased mortality14,16,36,61,62. One study showed that length of stay was significantly longer for the patients receiving a craniotomy > 4 hours after injury14.
Reliability: No studies identified.
Risk Adjustment: Age, GCS, CT findings of intracranial hemorrhage or herniation and prehospital time are variables that have been used for risk adjustment in studies examining time to ASDH evacuation63. Factors that could be considered to impact the measure that may warrant adjustment include geographic area (urban, rural), initial GCS, mechanism of injury and type of anatomical injuries.
Utilization: Time to Acute Subdural Hematoma Evacuation related indicators are used by a few trauma centers: USA 0.5% (1/200), Canada 0% (0/35), Australasia 0% (0/12).
Fung Kon Jin et al. described that having CT scanner in the trauma room reduces the time to surgical intervention in patients with severe traumatic brain injury64. Different time thresholds for ASDH evacuation have been proposed including 1 hour, 2 hours and 4 hours2,14,16,47,61,62.


The American College of Surgeons Committee on Trauma proposed the indicator Patients with Epidural Hematoma or Subdural Hematoma Receiving Craniotomy more than 4 hours after Arrival at ED32.


2. American College of Surgeons Committee on Trauma. Resources for Optimal Care of the Injured Patient 2006. Chicago: American College of Surgeons; 2006.
14. Nayduch D, Moylan J, Snyder BL, Andrews L, Rutledge R, Cunningham P. American College of Surgeons trauma quality indicators: an analysis of outcome in a statewide trauma registry. J Trauma. 1994;37(4):565-573; discussion 573-565.
16. Di Bartolomeo S, Valent F, Sanson G, Nardi G, Gambale G, Barbone F. Are the ACSCOT filters associated with outcome? Examining morbidity and mortality in a European setting. Injury. 2008;39(9):1001-1006.
32. Brown JB, Stassen NA, Bankey PE, Sangosanya AT, Cheng JD, Gestring ML. Helicopters improve survival in seriously injured patients requiring interfacility transfer for definitive care. J Trauma. 2011;70(2):310-314.
36. Willis CD, Stoelwinder JU, Cameron PA. Interpreting process indicators in trauma care: construct validity versus confounding by indication. Int J Qual Health Care. 2008;20(5):331-338.
47. Cryer HG, Hiatt JR, Fleming AW, Gruen JP, Sterling J. Continuous use of standard process audit filters has limited value in an established trauma system. J Trauma. 1996;41(3):389-394; discussion 394-385.
60. Brain Trauma Foundation. Guidelines for the management of severe traumatic brain injury: 3rd edition. J Neurotrauma. 2007;24(S1):S1-S106.
61. Wilberger JE, Harris M, Diamond DL. Acute subdural hematoma: morbidity and mortality related to timing of operative intervention. J Trauma. 1990;30(6):733-736.
62. Schwartz ML, Sharkey PW, Andersen JA. Quality assurance for patients with head injuries admitted to a regional trauma unit. J Trauma. 1991;31(7):962-967.
63. Tien HCN, Jung V, Pinto R, Mainprize T, Scales DC, Rizoli SB. Reducing time-to-treatment decreases mortality of trauma patients with acute subdural hematoma. Ann Surg. 2011;253(6):1178-1183.
64. Fung Kon Jin PH, Goslings JC, Ponsen KJ, van KC, Hoogerwerf N, Luitse JS. Assessment of a new trauma workflow concept implementing a sliding CT scanner in the trauma room: the effect on workup times. J Trauma. 2008;64(5):1320-1326.