Incidence of emergency neurosurgical TBI procedures: A population-based study

doi:10.21203/rs.3.rs-389391/v1

Download PDF

Research article

Incidence of emergency neurosurgical TBI procedures: A population-based study

https://doi.org/10.21203/rs.3.rs-389391/v1

This work is licensed under a CC BY 4.0 License

Journal Publication

published 06 Jan, 2022

Read the published version in BMC Emergency Medicine →

You are reading this latest preprint version

Background

The rates of emergency neurosurgery in traumatic brain injury (TBI) patients vary between populations and trauma centers. In planning acute TBI treatment, knowledge about rates and incidence of emergency neurosurgery at the population level is of importance. This study aimed to present incidence rates and patient characteristics for the most common TBI-related emergency neurosurgical procedures.

Methods

Oslo University Hospital is the only trauma center with neurosurgical services in Southeast Norway, which has a population of 3 million. We extracted prospectively collected registry data from the Oslo TBI Registry – Neurosurgery over a five-year period (2015–2019). For age-adjusted incidence according to the direct method, we used the 2013 European standard population (ESP) and 2000–2025 WHO World standard population distributions. We conducted multivariate logistic regression models to assess variables associated with emergency neurosurgical procedures.

Results

A total of 2151 patients with pathological head CT scans were included. One or more emergency neurosurgical procedure was performed in 27% of patients. The crude incidence was 3.9/100 000 person-years. The age-adjusted incidences in the standard population for Europe and the world were 4.0/100 00 and 3.3/100 000, respectively. The most frequent emergency neurosurgical procedure was the insertion of an intracranial pressure monitor, followed by evacuation of the mass lesion. Male sex, road traffic accidents, severe injury (low GCS) and CT characteristics such as midline shift and compressed/absent basal cisterns were significantly associated with an increased probability of emergency neurosurgery, while older age was associated with a decreased probability.

Conclusions

The incidence of emergency neurosurgery in the general population is low and reflects neurosurgery procedures performed in patients with severe injuries. Hence, emergency neurosurgery for TBIs should be centralized to major trauma centers.

Critical Care & Emergency Medicine

emergency

neurosurgery

traumatic brain injury

trauma center

The incidence of hospital-admitted patients with traumatic brain injury (TBI) in Western countries is in the range of 83–287 per 100 000 (1–8). Most commonly, TBI is divided into mild, moderate and severe; mild TBI encompasses the vast majority of cases and can often be cared for at emergency departments or local hospitals. In TBI patients where neurosurgery is indicated, established care pathways to transfer the patients to a level 1 trauma center are utilized. Even though surgery might not be indicated, patients with severe and moderate TBIs tend to benefit from management at centers with expertise and access to neurosurgery and neurosurgical intensive care units (9–11).

Guidelines have been developed to standardize the treatment of TBI, e.g., the Brain Trauma Foundation (BTF) which has published recommendations for the management of severe TBI, including indications for neurosurgical procedures (12, 13). However, several studies describe a varying degree of compliance with BTF recommendations and neurosurgical management (14–17). These variations can be explained by differences in the organization of health care, population composition, injury landscape, and available health care resources.

The reported frequencies of hospitalized TBI patients requiring emergency neurosurgery vary between 4 and 29% (18–23). Such rates are most often based on patients in a study center, and thus they are not representative of the general population, per se. The population-based incidence of emergency neurosurgery for patients with TBI has not yet been reported. Estimation of the incidence of emergency neurosurgery in a defined general population is important to develop adequate care pathways that can be used to predict capacity development, understand resource use and identify high-risk groups for emergency neurosurgery. Such knowledge can assist in the future management of TBI and the distribution of neurosurgical resources, as well as facilitating quality control studies of neurosurgical services, both locally and between countries.

In this study, we present contemporary real-world incidence rates and patient characteristics for the most common TBI-related emergency neurosurgical procedures in a Western general population of 3 million people. Additionally, we explored the association between demographics, injury-related characteristics and emergency neurosurgical procedures.

Setting and patient population

Oslo University Hospital (OUH) is a Level 1 trauma center and the only hospital with a neurosurgical department in the southeastern region of Norway, which has 3.0 million inhabitants. The region encompasses 19 local hospitals that provide acute care and general surgical assessment, management and stabilization. Trauma patients with severe injuries or suspected severe TBI are directly transported and admitted to OUH. OUH also serves as the primary trauma referral hospital for Oslo residents (population ≈ 700 000) and manages the Oslo Emergency Department (separate location from the main hospital). All emergency neurosurgical TBI procedures in the southeastern region of Norway are solely performed at OUH (intracranial pressure monitoring, evacuation traumatic intracranial mass lesion, cerebrospinal fluid (CSF) diversion and decompressive craniectomy). Norway provides universal healthcare to all Norwegian residents.

The Oslo TBI Registry – Neurosurgery is a prospective quality control database that has been maintained by the neurosurgical department at OUH since 2015. Data were retrieved manually from electronic medical records and stored in a Medinsight database. To be included in the Oslo TBI Registry – Neurosurgery, all of the following criteria must be fulfilled: (i) traumatic brain injury; (ii) cerebral CT/CTA or cerebral MRI/MRA with findings of acute trauma (hemorrhage, fracture, traumatic axonal injury, vascular injury); (iii) admission to OUH within seven days of injury; and (iv) a Norwegian social security number. A more thorough description of the database and patient characteristics has been previously described (24). Data were retrieved for patients admitted between January 1, 2015, and December 31, 2019, on September 4, 2020. Population data for the same period were retrieved from the StatBank of Statistics Norway (25).

Variables

The preinjury American Society of Anesthesiologists Physical Status Classification System score (ASA) (26) was grouped into two categories: ASA 1–2 or ASA 3–4. Trauma mechanisms were grouped into (i) falls; (ii) road traffic accidents (RTAs) (including all accidents involving motor vehicles, cyclists and pedestrians); and (iii) others (including assaults, sports, and self-harm). High energy included falls from a height ≥ 3 meters, RTAs, or other high-energy accidents. Extracranial injury was registered if there were any simultaneous injuries to other parts of the body.

Referrals to OUH were categorized as (i) primary: directly from the scene of an accident; (ii) secondary: initial assessment at a local hospital; and (iii) other: Oslo Emergency Department or other. Trauma team activation: The OUH trauma team is a specially trained interdisciplinary team that systematically assesses the patients upon arrival according to the advanced trauma life support (ATLS) principles (27). Intubation was registered when performed at the scene of accident, at a local hospital or at admission to OUH. Admission to the intensive care unit (ICU) included all patients admitted to the ICU, whereas uncomplicated short stays (< 24 hours) for TBI observation in the intermediate/step-down unit were registered as ward admissions.

The Glasgow coma score (GCS) was recorded as the lowest score documented in the time frame between injury and intubation or arrival at OUH. We grouped patients based on GCS score into mild (13–15), moderate (9–12), and severe (3–8) head injury. Preoperative head CT was assessed and classified based on the Rotterdam CT score (28). The Rotterdam CT score emphasizes the status of basal cisterns (dichotomized into normal or compressed/absent), midline shift (0–5 mm or > 5 mm), epidural hematoma (present or absent), and traumatic subarachnoid hemorrhage/intraventricular hemorrhage (tSAH/IVH) (present or absent).

We defined “emergency neurosurgical procedure” as undergoing one or more neurosurgical procedures aiming to monitor and/or reduce intracranial pressure (ICP); including insertion of parenchymal ICP monitoring, craniotomy with removal of mass lesions (acute subdural hematoma, epidural hematoma, intracerebral contusion), decompressive hemicraniectomy (DC), or CSF diversion by insertion of external ventricular drains (EVDs). Treatment of TBI at OUH follows the Brain Trauma Foundation guidelines, and indications for surgery are based on international recommendations (13, 29, 30) and presented in Table 1.

Table 1

OUH treatment protocol - indication for emergency neurosurgical procedures
Procedure	Indication
ICP-monitor	GCS < 9 and abnormal CT GCS < 9, normal CT and ≥ 2 of following features: age > 40 years systolic BP < 90 mmHg GCS Motor (GCS M) < 4 (best side) GCS < 13 and: prolonged surgery in other organ systems expected prolonged ventilator therapy due to other injuries
Evacuation of ASDH (acute subdural hematoma)	GCS < 14 and: hematoma volume > 30 ml or midline shift > 5 mm or hematoma width > 10 mm
Evacuation of EDH (epidural hematoma)	GCS < 14 and: hematoma volume > 30 ml or midline shift > 5 mm or hematoma width > 15 mm
Evacuation of cerebral contusion	GCS < 12 and: contusion volume > 20 ml or midline shift > 5 mm In case of contusion in the eloquent cortex (motor cortex, language area), decompressive craniectomy should be considered instead of evacuation of the contusion
CSF diversion	ICP > 22 mmHg for 10 minutes ICP > 25 mmHg for 5 minutes
Decompressive craniectomy (DC)	Persisting ICP > 22 mmHg despite all neuroprotective efforts (circulation, ventilation, sedation, positioning, temperature regulation, osmotherapy, CSF-diversion) If evacuation of mass lesion alone does not provide ICP control When CT and clinical presentation are compatible with a meaningful life Age < 60 years
OUH, Oslo University Hospital; ICP, intracranial pressure; GCS, Glasgow coma score; GCS M, GCS motor score; CSF, cerebrospinal fluid

Statistical analysis

Descriptive statistics were used to summarize patient characteristics and emergency neurosurgical procedures. Continuous variables are presented as the mean and standard deviation (SD) or median and percentile, depending on the data distribution. For comparisons between groups, we used the Pearson χ2 test for categorical variables and the independent t-test for continuous variables. Incidence per 100 000 was calculated in person years. For age-adjusted incidence according to the direct method, we used the 2013 European standard population (ESP) and the 2000–2025 WHO World standard population. We conducted multivariate logistic regression models to assess variables associated with emergency neurosurgical procedures. For categorical variables, the category with lowest severity was used as the reference, “no/absent” was coded as 0 and “yes/present” was coded as 1. The results are presented as odds ratios (ORs) with 95% confidence intervals (CIs) and p-values. Two-sided p-values of 0.05 were considered statistically significant. Data were analyzed using IBM SPSS Statistics, version 25.0 (Armonk, NY: IBM Corp).

Ethics

The OUH data protection officer (DPO) approved the Medinsight database (approval number 2016/17569) and approved this study as a quality control study (approval number 18/20658).

Included in this study were 2,151 patients with TBI admitted at OUH during the five-year period 2015–2019. The mean age was 52 years (SD 25); 37% were ≥ 65 years, and 68% were males. Preinjury comorbidity with ASA scores ≥ 3 was registered in 28%. Trauma mechanisms were falls in 1186 (55%) patients, RTA in 488 (23%) patients and other in 477 (22%) patients. The head injury was blunt in 98% and penetrating in 2%. The median time from injury to OUH admittance was 3 hours (IQR 1.3–6.6 hours), and 37% were admitted directly from the scene of the accident. Trauma team triage was performed for the majority of patients (77%), 34% were intubated before arrival or in the ER, and close to half had multiple injuries (47%). TBI was classified as mild, moderate and severe in 59%, 15% and 26%, respectively. Patient characteristics are provided in Table 2.

Table 2

Demographic and clinical characteristics of the study population
	Overall	Neurosurgery^a	No-neurosurgery	p-value
Total, N (%)	2151 (100)	569 (100)	1582 (100)
Age, years (mean, SD)	52 (25)	49 (22)	54 (25)	< .001
Male	1466 (68)	425 (75)	1041 (66)	< .001
Preinjury ASA score
ASA 1–2	1543 (72)	416 (73)	1127 (71)	.39
ASA 3–4	608 (28)	153 (27)	455 (29)	.39
Antithrombotic therapy	545 (25)	115 (20)	430 (27)	.001
Preinjury substance dependence	325 (15)	113 (20)	212 (13)	< .001
High-energy trauma	810 (38)	281 (49)	529 (33)	< .001
Extracranial injury	1014 (47)	322 (57)	692 (44)	< .001
Alcohol at time of injury	580 (27)	171 (30)	409 (26)	.053
Glasgow coma score (GCS)
13–15	1267 (59)	108 (19)	1159 (73)	< .001
9–12	334 (15)	111 (20)	223 (14)
3–8	550 (26)	350 (62)	200 (13)
CT findings
Midline shift > 5 mm	353 (16)	216 (38)	137 (9)	< .001
Basal cisterns compressed or absent	350 (16)	228 (40)	122 (8)	< .001
tSAH or IVH	1287 (60)	402 (71)	886 (56)	< .001
EDH	333 (16)	141 (25)	192 (12)	< .001
ASDH	1185 (55)	407 (72)	778 (49)	< .001
Intracerebral contusion	1030 (48)	352 (62)	678 (43)	< .001
CT Rotterdam score
1–2	848 (39)	133 (23)	715 (45)	< .001
3–4	1122 (52)	335 (59)	787 (50)
5–6	181 (8)	101 (18)	80 (5)
Referral to OUH
Primary	800 (37)	272 (48)	528 (33)	< .001
Secondary	815 (38)	269 (47)	546 (35)
Other	536 (25)	28 (5)	508 (32)
Trauma team activation	1655 (77)	533 (94)	1122 (71)	< .001
Intubated	721 (34)	462 (81)	259 (16)	< .001
Any extracranial surgery	459 (21)	171 (30)	288 (18)	< .001
Admitted intensive care unit	1457 (68)	568 (100)	889 (56)	< .001
In-hospital mortality	173 (8)	63 (11)	110 (7)	.002
GCS 15 at discharge	1356 (63)	170 (30)	1186 (75)	< .001
ASDH, acute subdural hematoma; EDH, epidural hematoma; IVH, Intraventricular hemorrhage; OUH, Oslo University Hospital; tSAH, Traumatic subarachnoid hemorrhage
Categorical variables presented as N (%), continuous variables presented as the mean (SD) or median (IQR).
^aPatient undergoing one or more of the following procedures (redo surgeries are not included): ICP-monitor, evacuation of intracranial mass lesion (epidural hematoma, acute subdural hematoma, intracerebral contusion), decompressive craniectomy, external ventricular drain

To determine the incidence of neurosurgical procedures, patients were divided into two groups: the “neurosurgery group” (N = 569) who underwent one or more emergency neurosurgical procedures and “no-neurosurgery group” (N = 1582) (Table 2). Comparing the two, the neurosurgery group was characterized by younger age, a higher proportion of males, a lower proportion on antithrombotic medication, more high-energy trauma, more extracranial injuries, shorter median time from injury to admittance at OUH, lower GCS score, and higher Rotterdam CT-score. The two groups did not differ with respect to the preinjury ASA score or alcohol influence at the time of injury. In-hospital mortality was higher in the neurosurgery group (11% vs 7%, p = .002) and had significantly fewer patients with GCS 15 at discharge (30% vs 75%, p = < .001).

Incidence and type of emergency neurosurgical procedures

The crude incidence of patients receiving one or more emergency neurosurgical procedures was 3.9/100 000 person-years (Table 3). The age-adjusted incidences in the standard population for Europe and the world were 4.0/100 00 and 3.3/100 000, respectively. Emergency neurosurgical procedures were performed in 27% of patients; this rate varied from 21% (in 2019) to 32.5% (in 2016), and the yearly incidence was in the range of 3.3–4.8/100 000 person-years. Age-specific incidence is presented in Fig. 1, showing a peak incidence between 61 and 84 years. The highest incidence was 7.4/100 000 person-years in the 70-74-year age group. Table 3 and Figs. 2A-B present the incidences and rates for the different neurosurgical procedures.

Table 3

Emergency neurosurgical procedures: number of patients, age, male proportion and incidence
	Total, N (%)	Age, mean (SD)	Male, N (%)	Incidence per 100 000, person-years
	Total, N (%)	Age, mean (SD)	Male, N (%)	Crude incidence^a	Age adjusted, Europe^b	Age adjusted, World^c
Any procedure	569 (100)	49 (22)	425 (75)	3.87	4.00	3.33
ICP monitor	476 (84)	47 (21)	356 (75)	3.24	3.32	2.84
Evacuation of mass lesion	284 (50)	52 (21)	215 (75)	1.93	2.03	1.55
ASDH	184 (32)	59 (18)	133 (72)	1.25	1.35	0.88
EDH	80 (14)	35 (19)	67 (83)	0.54	0.53	0.58
Intracerebral contusion	57 (10)	56 (18)	42 (74)	0.39	0.41	0.28
EVD	119 (21)	46 (20)	84 (71)	0.81	0.82	0.72
DC	44 (8)	40 (18)	35 (80)	0.30	0.30	0.29
ASDH, acute subdural hematoma; EDH, epidural hematoma; EVD, external ventricular drain; DC, decompressive craniectomy
Redo surgeries are not included
^aPopulation of South-East Norway in person years (2015–2019): 14,740,114
^bEuropean standard population 2013, EU-27 + EFTA
^cWHO World standard population: WHO 2000–2025

The most frequent emergency neurosurgical procedure was insertion of an ICP-monitor (476 patients) with an incidence of 3.2/100 000 person-years. The rate of ICP-monitor insertion increased with increasing age, peaked in the 60-year age group and dropped in patients > 75 years (Fig. 2A). This was the only emergency neurosurgical procedure in 39% of cases (184/476). An ICP monitor was inserted in 61% of patients with a GCS ≤ 8 (336/550) and in 26% of patients with a GCS 9–12 (87/334).

The second most frequent emergency neurosurgical procedure was evacuation of an intracranial mass lesion, performed in 13% (284/2151 patients), resulting in an incidence of 1.9/100 000 person-years. The most frequent intracranial mass lesion evacuated was ASDH, followed by EDH and brain contusions (Fig. 2B). The age profile for evacuation of an intracranial mass lesion was similar to that of ICP monitor insertion (Fig. 2A). After stratifying by the three types of intracranial mass lesions evacuated, the age profile differed (Fig. 2B). Evacuation of ASDH was most frequent in patients aged 60–74 years, while evacuation of EDH was most frequent in patients aged < 45 years. Cerebral contusions were most often evacuated in patients aged 45–74 years and rarely in very young or very old patients. In patients with ASDH present on primary CT, the hematomas were evacuated in 16% (184/1185); the corresponding proportions for EDH and intracerebral contusion were 24% (80/333) and 6% (57/1030), respectively. EVD insertion was rare in all age groups (Fig. 2A) (5.5%, 119/2151). Decompressive craniectomy (DC) was also rarely performed (2%, 44/2151) but was most commonly performed in patients aged 15–59 years. DC was never performed in patients > 80 years. Frequencies are presented in Table 3.

The multivariate logistic regressions of factors potentially associated with emergency neurosurgery showed that male sex, RTA, low GCS and CT characteristics with midline shift and compressed/absent basal cisterns were significantly associated with an increased probability of emergency neurosurgery, whereas high age (> 75 years) was associated with decreased probability. These results are presented in Table 4. The pattern was similar for insertion of an ICP-monitor, but for this procedure, the most significant association was for low GCS 3–8 (OR 29.1, 95% CI 20.3, 41.7). For evacuation of intracranial mass lesions, the presence of a midline shift was the strongest factor (OR 19.2, 95% CI 12.9, 28.7).

Table 4

Multiple logistic regression of potential factors associated with emergency neurosurgical procedures, placement of ICP-monitor and evacuation of mass lesion
Variable	Emergency neurosurgery^a		ICP monitor		Evacuation mass lesion
Variable	OR (95% CI)	p-value	OR (95% CI)	p-value	OR (95% CI)	p-value
Age
0–14 years	1		1		1
15–29 years	1.15 (.68, 1,96)	.60	1.43 (.79, 2.60)	.24	.62 (.30, 1.28)	.20
30–44 years	1.06 (.61, 1.83)	.84	1.17 (.63, 2.17)	.63	.81 (.40, 1.63)	.55
45–59 years	1.29 (.77, 2.17)	.33	2.10 (1.16. 3.77)	.01	.54 (.27, 1.08)	.08
60–74 years	1.10 (.65, 1.87)	.72	1.44 (.79, 2.62)	.23	.52 (.26, 1.04)	.07
75–89 years	.41 (.22, .77)	.00	.38 (.18, .78)	.01	.23 (.10, .52)	< .001
90 + years	.10 (.02, .43)	.01	.05 (.01, .47)	.01	.14 (.03, .60)	.01
Sex
Female	1		1		1
Male	1.49 (1.13, 1.97)	.01	1.48 (1.05, 1.94)	.02	1.86 (1.28, 2.70)	.00
ASA-score
1–2	1		1		1
3–4	.92 (.66, 1.29)	.63	.76 (.52, 1.09)	.14	1.33 (.88, 2.01)	.18
Antithrombotic
None	1		1		1
Plate inhibitor	1.02 (.64, 1.60)	.95	1.48 (.90, 2.43)	.13	.72 (.39, 1.31)	.28
Anticoagulation	.75 (.43, 1.31)	.32	.88 (.48, 1.62)	.69	.63 (.34, 1.18)	.15
Combination	2.20 (1.06, 4.54)	.03	1.57 (.64, 3.89)	.33	1.57 (.66, 3.71)	.31
Trauma type
Fall	1		1		1
RTA	1.76 (1.29, 2.40)	< .001	1.97 (1.40, 2.77)	< .001	1.10 (.71, 1.70)	.67
Other	1.16 (.84, 1.60)	.37	1.15 (.81, 1.63)	.43	.92 (.61, 1.40)	.70
GCS
13–15	1		1		1
9–12	4.40 (3.19. 6.05)	< .001	7.17 (4.89, 10.51)	< .001	2.21 (1.44, 3.41)	< .001
3–8	12.47 (9.27, 16.77)	< .001	29.12 (20.34, 41.69)	< .001	1.27 (.83, 1.95)	.27
Midline shift
No (≤ 5 mm)	1		1		1
Yes (> 5 mm)	3.69 (2.58, 5.29)	< .001	1.50 (1.01, 2.23)	.05	19.23 (12.88, 28.70)	< .001
Basal cisterns
Normal	1		1		1
Compressed/absent	1.75 (1.23, 2.50)	.00	1.20 (1.36, 2.92)	< .001	2.52 (1.63, 3.88)	< .001
OR, odds ratio; CI, confidence interval
^aPatient undergoing one or more of the following procedures (redo surgeries are not included): ICP-monitor, evacuation of mass lesion, decompressive craniectomy, external ventricular drain

The incidence of emergency neurosurgery for TBI in the general Norwegian population was 3.9/100 000 person years over the five-year study period. Insertion of an ICP-monitor was the most frequent procedure, followed by evacuation of an intracranial mass lesion. Overall, emergency neurosurgery was associated with male sex, RTA, low GCS and CT characteristics with midline shift and compressed/absent basal cisterns. The incidence of emergency neurosurgery decreased in elderly patients.

The frequencies of emergency neurosurgery are in accordance with previous research comparing subgroups within the TBI population (18–23). However, to our knowledge, this study is the first to describe a general population-based incidence of emergency neurosurgery. It must be taken into consideration that the type of injury mechanism differs globally; in low- and middle-income countries, RTA is the most common cause and access to neurosurgery is more limited (10). We found the incidence of emergency neurosurgery (3.9/100 000 person-years) to be quite low compared to the reported incidence of hospital-admitted TBI patients (83–287/100 000) (1–8). The discrepancy between the rate of emergency surgery and hospital admission rates can partly be explained by guideline recommendations for the initial management of head injuries. To identify the few patients in need of neurosurgery, screening with head CT must be performed with a rather low threshold, e.g., according to the Scandinavian guidelines for the initial management of minimal, mild and moderate head injuries (31). Thus, minor lesions less likely to require emergency neurosurgery are frequently identified. In line with previous studies, low GCS and CT characteristics such as midline shift and compressed basal cisterns, were strong predictors for emergency neurosurgery (13, 32, 33). Given the low rate of emergency neurosurgery, it is evident that only a few centers in each country or region can provide competent neurosurgical services. As patients with TBI are often admitted outside of ordinary working hours, it is important that competent personnel are available 24 hours a day and 7 days a week to provide the best possible treatment for TBI (24). To achieve this, optimal collaboration and organization between hospitals is imperative, irrespective of distance to the trauma center.

The incidence of emergency neurosurgery varied with age; it was low in children and peaked in the 60–70 year age group. To some extent, this reflects the epidemiological shift described over the last decade in high-income countries – the typical TBI patient has changed from a young male, injured in a high-energy trauma, to an elderly man or woman, often with significant comorbidity, injured in a low-energy fall (21, 23, 34, 35). Male sex was significantly associated with an increased probability of emergency neurosurgery in this study. Males are seemingly more likely to take risks (36), which may explain this overrepresentation. The incidence of emergency neurosurgery declined abruptly in patients above 85 years, which was somewhat unexpected since the incidence of TBI-related hospital admissions is highest for the eldest patients (21, 34). Decisions to limit treatment are more often made for older patients (37, 38), and for many of these patients, it is justified to refrain from emergency neurosurgery based on poor prognosis, severe comorbidity, and frailty (39, 40). The use of age alone as a criterion for treatment limitation must be practiced with caution, since several studies have shown that older patients may benefit from aggressive treatment and access to rehabilitation (41–47). A previous study from our institution demonstrated that the management intensity of hospitalized patients with TBI decreased with advanced age and that low management intensity was associated with an increased risk of 30-day mortality (48). Thus, the high mortality among elderly TBI patients may have an element of self-fulfilling prophecies and may, in the future, be reduced with a more aggressive management regimen.

The most frequently performed emergency neurosurgical procedure was the insertion of an ICP monitor. According to the BTF guidelines, ICP monitoring is recommended for all salvageable TBI patients with an abnormal head CT and a GCS ≤ 8 (12). In our study, GCS ≤ 8 was the strongest factor associated with insertion of an ICP monitor; 61% of patients with GCS ≤ 8 received an ICP monitor. This is in line with a European multicenter study where the proportion was 62% (23). In North American studies, the rate of ICP monitoring of severe TBI patients ranges from 10–65% (15, 16, 49).In our study, 26% of patients with GCS 9–12 also received an ICP monitor. The indication for ICP monitoring in this group was mainly prolonged surgery or expected prolonged ventilator treatment due to other injuries, which is in accordance with our local protocol. There is agreement between most published studies that the management of patients with severe head injury is facilitated by intracranial pressure monitoring (12, 50, 51). The superiority of ICP monitor-guided management was, however, questioned in a randomized controlled trial by Chesnut et al. (52), who found little difference between ICP monitoring and management guided by neurologic examination and serial CT imaging. The latter form of management poses difficulties with intubated patients and with the transfer of patients to and from the radiology department together with an added radiation dose exposure.

Evacuation of intracranial mass lesions was the second most frequent emergency neurosurgical procedure, with an incidence of 1.9/100 000. Overall, evacuation of mass lesions was performed in 13% of CT-verified TBI patients admitted to our institution, which is in line with other studies with similar patient populations, ranging from 9–18% (19, 21, 23). All patients with imaging-verified ASDH, EDH, or brain contusion should, according to the guidelines, be admitted for observation and surgical treatment if necessary (31, 53). ASDH was the most frequent mass lesion evacuated; it was performed in all age groups but more often in elderly patients, which is in line with other studies (23, 32–34). In our study, 16% of the patients with ASDH present on primary CT underwent craniotomy with evacuation of ASDH, which is in line with the 13% reported by Esposito et al. (18). EDH is known to be more frequent in younger people because the dura adheres more tightly to the skull with age (30). Thus, as expected, evacuation of EDH was most often performed in patients aged < 45 years. Of patients with EDH present on CT scan, 24% had a craniotomy, which is somewhat higher than the rate of 17% reported by Esposito et al. (18). Evacuation of cerebral contusions was most often done in patients aged 45–74 years, rarely in the younger and older patient groups, and in only 6% of those with contusion present on CT scan. This corresponds to the 2–10% reported by others (23, 33, 34). In the majority of patients observed in the hospital for a traumatic intracranial lesion, the lesion will not progress to a size requiring surgical evacuation. However, the rates of surgery presented here clearly indicate that close observation of admitted patients with intracranial mass lesions is necessary. The size of the mass lesion and midline shift are factors included in the decision algorithm for evacuation of traumatic intracranial mass lesions. In our study, a midline shift ≥ 5 mm on cerebral CT was the predominant factor associated with evacuation of mass lesions, along with compressed basal cisterns, while increasing age and the use of anticoagulants were associated with decreased probability. The size of the mass lesions was not measured in our study, but the degree of midline shift and the status of the basal cisterns are good indirect measures of the volume of intracranial mass lesions. Since volume measures were not done, it is difficult to evaluate if we succeeded in following the treatment recommendation for surgical evacuation of mass lesions given in Table 1.

At our institution, EVDs are used to reduce elevated ICP, and not primarily to monitor ICP. The main reason behind this treatment strategy is the risk of infection associated with EVD, and that an intraparenchymal ICP sensor causes less surgical trauma (54–56). The current trend in our department is to more actively use CSF drainage to decrease ICP with the intention of reducing the time on a ventilator and amount of sedation.

Decompressive craniectomy (DC) for severe TBI is still regarded as a treatment with limited documented benefit and is a treatment rarely documented in patients ≥ 65 years (44, 45, 57–59). The two main indications, as supported by published guidelines (60, 61), for DC at our institution have been as a last resort management option for refractory raised ICP and in cases with severe intraoperative brain swelling, similar to other European trauma centers (17).

Strength and limitations

This study presents a population-based incidence of real-world TBI emergency neurosurgical procedures over a total period of five years from a defined geographical region covering both large rural and urban areas. The region has a defined written criterion for emergency neurosurgery and a stable all-hour presence of neurosurgeons. Data were retrieved manually, thus avoiding bias of potential medical coding errors, which is a risk with aggregated data from national registries.

A limitation of this study is the lack of detailed information about the anatomical localization or volumetry of the traumatic intracranial mass lesions. Moreover, the study is restricted to what we defined as emergency neurosurgical procedures. Hence, we do not describe all neurosurgical procedures relevant for TBI patients; e.g., cranioplasty, dural repair or redo-surgery, and surgery at later stages, such as replacement of bone flaps, shunts and chronic subdural hematoma, were not included.

The incidence of emergency neurosurgery after TBI in the general population is low; hence, emergency neurosurgery should be centralized to a major trauma center that has adequate resources, staffing levels and neurosurgery training. Emergency neurosurgery was associated with male sex, RTA, low GCS and CT characteristics such as midline shift and compressed/absent basal cisterns.

ASA-PS

American Society of Anesthesiologists Physical Status Classification System score

ASDH

Acute subdural hematoma

Confidence interval

CCP

Cerebral perfusion pressure

CSF

Cerebrospinal fluid

Computed tomography

Decompressive craniectomy

DPO

Data protection officer

Emergency department

EDH

Epidural hematoma

EVD

External ventricular drainage

GCS

Glasgow coma score

ICP

Intracranial pressure

ICU

Intensive care unit

IVH

Intraventricular hemorrhage

LOS

Length of stay

RTA

Road traffic accident

Odds ratio

OUH

Oslo University Hospital

TBI

Traumatic brain injury

tSAH

Traumatic subarachnoid hemorrhage

Ethics approval and consent to participate

Anonymized data was retrieved from the Oslo TBI Registry. The Registry was approved by OUH data protection officer (approval number 2016/17569). This study qualifies as a quality control study, hence application to the regional ethical committee was waived (62). The study was approved by OUH data protection officer (approval number 18/20658).

Consent for publication

Not applicable

Availability of data and materials

The datasets generated and/or analyzed during the current study are not publicly available due to the sensitivity of the material, but they are available from the corresponding author on reasonable request.

Competing interests

The authors declare no conflict of interest

Funding

No external founding.

Authors’ contribution

Conception and design: CT and EH. Data collection: OS, CT, EH. Analysis and drafting of the manuscript: CT, EH, NA. All authors contributed substantially to the revision of the manuscript and approved the final manuscript.

Acknowledgements

Not applicable

Peeters W, van den Brande R, Polinder S, Brazinova A, Steyerberg EW, Lingsma HF, et al. Epidemiology of traumatic brain injury in Europe. Acta Neurochir (Wien). 2015;157(10):1683-96.
Centers for Disease Control and Prevention. Surveillance Report of Traumatic Brain Injury-related Emergency Department Visits, Hospitalizations, and Deaths—United States, 2014. Centers for Disease Control and Prevention, U.S. Department of Health and Human Services; 2019.
Koskinen S, Alaranta H. Traumatic brain injury in Finland 1991-2005: a nationwide register study of hospitalized and fatal TBI. Brain Inj. 2008;22(3):205-14.
Pedersen K, Fahlstedt M, Jacobsson A, Kleiven S, von Holst H. A National Survey of Traumatic Brain Injuries Admitted to Hospitals in Sweden from 1987 to 2010. Neuroepidemiology. 2015;45(1):20-7.
Andelic N, Sigurdardottir S, Brunborg C, Roe C. Incidence of hospital-treated traumatic brain injury in the Oslo population. Neuroepidemiology. 2008;30(2):120-8.
Heskestad B, Baardsen R, Helseth E, Romner B, Waterloo K, Ingebrigtsen T. Incidence of hospital referred head injuries in Norway: a population based survey from the Stavanger region. Scand J Trauma Resusc Emerg Med. 2009;17:6.
Rickels E, von Wild K, Wenzlaff P. Head injury in Germany: A population-based prospective study on epidemiology, causes, treatment and outcome of all degrees of head-injury severity in two distinct areas. Brain Inj. 2010;24(12):1491-504.
Majdan M, Plancikova D, Brazinova A, Rusnak M, Nieboer D, Feigin V, et al. Epidemiology of traumatic brain injuries in Europe: a cross-sectional analysis. Lancet Public Health. 2016;1(2):e76-e83.
Badjatia N, Carney N, Crocco TJ, Fallat ME, Hennes HM, Jagoda AS, et al. Guidelines for prehospital management of traumatic brain injury 2nd edition. Prehosp Emerg Care. 2008;12 Suppl 1:S1-52.
Maas AIR, Menon DK, Adelson PD, Andelic N, Bell MJ, Belli A, et al. Traumatic brain injury: integrated approaches to improve prevention, clinical care, and research. The Lancet Neurology. 2017;16(12):987-1048.
Sollid S, Sundstrom T, Ingebrigtsen T, Romner B, Wester K. Organisation of traumatic head injury management in the Nordic countries. Emerg Med J. 2009;26(11):769-72.
Carney N, Totten AM, O'Reilly C, Ullman JS, Hawryluk GW, Bell MJ, et al. Guidelines for the Management of Severe Traumatic Brain Injury, Fourth Edition. Neurosurgery. 2017;80(1):6-15.
Bullock M, Chesnut R, Ghajar J, Gordon D, Hartl R, Newell DW, et al. Surgical management of traumatic brain injury. Neurosurgery. 2006;58(3):S2-S61.
Cnossen MC, Polinder S, Andriessen TM, van der Naalt J, Haitsma I, Horn J, et al. Causes and Consequences of Treatment Variation in Moderate and Severe Traumatic Brain Injury: A Multicenter Study. Crit Care Med. 2017;45(4):660-9.
Hoffman H, Bunch KM, Furst T, Chin LS. Use of Intracranial Pressure Monitoring in Patients with Severe Traumatic Brain Injury. World Neurosurg. 2020;142:e385-e95.
Piccinini A, Lewis M, Benjamin E, Aiolfi A, Inaba K, Demetriades D. Intracranial pressure monitoring in severe traumatic brain injuries: a closer look at level 1 trauma centers in the United States. Injury. 2017;48(9):1944-50.
van Essen TA, den Boogert HF, Cnossen MC, de Ruiter GCW, Haitsma I, Polinder S, et al. Variation in neurosurgical management of traumatic brain injury: a survey in 68 centers participating in the CENTER-TBI study. Acta Neurochir (Wien). 2018.
Esposito TJ, Reed RL, 2nd, Gamelli RL, Luchette FA. Neurosurgical coverage: essential, desired, or irrelevant for good patient care and trauma center status. Ann Surg. 2005;242(3):364-70; discussion 70-4.
Joseph B, Haider AA, Pandit V, Tang A, Kulvatunyou N, OʼKeeffe T, et al. Changing paradigms in the management of 2184 patients with traumatic brain injury. Ann Surg. 2015;262(3):440-8; discussion 6-8.
Lecky FE, Russell W, McClelland G, Pennington E, Fuller G, Goodacre S, et al. Bypassing nearest hospital for more distant neuroscience care in head-injured adults with suspected traumatic brain injury: findings of the head injury transportation straight to neurosurgery (HITS-NS) pilot cluster randomised trial. BMJ open. 2017;7(10):e016355.
Maegele M, Lefering R, Sakowitz O, Kopp MA, Schwab JM, Steudel WI, et al. The Incidence and Management of Moderate to Severe Head Injury. Deutsches Arzteblatt international. 2019;116(10):167-73.
Stranjalis G, Bouras T, Korfias S, Andrianakis I, Pitaridis M, Tsamandouraki K, et al. Outcome in 1,000 head injury hospital admissions: the Athens head trauma registry. J Trauma. 2008;65(4):789-93.
Steyerberg EW, Wiegers E, Sewalt C, Buki A, Citerio G, De Keyser V, et al. Case-mix, care pathways, and outcomes in patients with traumatic brain injury in CENTER-TBI: a European prospective, multicentre, longitudinal, cohort study. Lancet Neurol. 2019;18(10):923-34.
Tverdal C, Aarhus M, Andelic N, Skaansar O, Skogen K, Helseth E. Characteristics of traumatic brain injury patients with abnormal neuroimaging in Southeast Norway. Injury epidemiology. 2020;7(1):45.
Statistics Norway. Statbank – Population. 2020. https://www.ssb.no/en/statbank/table/01222. Accessed 29 Apr 2020.
American Society of Anesthesiologists. ASA Physical Status Classification System. 2014. https://www.asahq.org/standards-and-guidelines/asa-physical-status-classification-system. Accessed 11 Aug 2019.
ATLS Advanced trauma life support : Student course manual, 10th edition. Chicago: American College of Surgeons. 2018. https://viaaerearcp.files.wordpress.com/2018/02/atls-2018.pdf. Accessed 12 Dec 2020.
Maas AI, Hukkelhoven CW, Marshall LF, Steyerberg EW. Prediction of outcome in traumatic brain injury with computed tomographic characteristics: a comparison between the computed tomographic classification and combinations of computed tomographic predictors. Neurosurgery. 2005;57(6):1173-82; discussion -82.
Aarhus M, Helseth E, Sunde K. Traumemanualen. Hodeskader [Head injuries]: Oslo University Hospital. 2016. https://www.traumemanualen.no/index.php?action=showtopic&topic=JZMwkGD3. Accessed 19 Oct 2020.
Sundstrøm T, Grände PO, Luoto T, Rosenlund C, Undén J, Wester KG. Management of Severe Traumatic Brain Injury. Switzerland: Springer International Publishing; 2020.
Unden J, Ingebrigtsen T, Romner B. Scandinavian guidelines for initial management of minimal, mild and moderate head injuries in adults: an evidence and consensus-based update. BMC Med. 2013;11:50.
Gómez PA, Castaño-León AM, Lora D, Cepeda S, Lagares A. Trends in computed tomography characteristics, intracranial pressure monitoring and surgical management in severe traumatic brain injury: Analysis of a data base of the past 25 years in a neurosurgery department. Neurocirugia (Astur). 2017;28(1):1-14.
Rossi-Mossuti F, Fisch U, Schoettker P, Gugliotta M, Morard M, Schucht P, et al. Surgical Treatment of Severe Traumatic Brain Injury in Switzerland: Results from a Multicenter Study. Journal of neurological surgery Part A, Central European neurosurgery. 2016;77(1):36-45.
Posti JP, Sipilä JOT, Luoto TM, Rautava P, Kytö V. A decade of geriatric traumatic brain injuries in Finland: population-based trends. Age Ageing. 2020;49(5):779-85.
Stocchetti N, Paternò R, Citerio G, Beretta L, Colombo A. Traumatic brain injury in an aging population. J Neurotrauma. 2012;29(6):1119-25.
Byrnes JP, Miller DC, Schafer WD. Gender differences in risk taking: a meta-analysis. Psychol Bull. 1999;125(3):367.
Jochems D, van Wessem KJP, Houwert RM, Brouwers HB, Dankbaar JW, van Es MA, et al. Outcome in Patients with Isolated Moderate to Severe Traumatic Brain Injury. Crit Care Res Pract. 2018;2018.
Robertsen A, Forde R, Skaga NO, Helseth E. Treatment-limiting decisions in patients with severe traumatic brain injury in a Norwegian regional trauma center. Scand J Trauma Resusc Emerg Med. 2017;25(1):44.
Castillo-Angeles M, Cooper Z, Jarman MP, Sturgeon D, Salim A, Havens JM. Association of Frailty With Morbidity and Mortality in Emergency General Surgery By Procedural Risk Level. JAMA surgery. 2020;156(1):68-74.
George EL, Hall DE, Youk A, Chen R, Kashikar A, Trickey AW, et al. Association Between Patient Frailty and Postoperative Mortality Across Multiple Noncardiac Surgical Specialties. JAMA surgery. 2020;156(1):e205152.
Anke A, Andelic N, Skandsen T, Knoph R, Ader T, Manskow U, et al. Functional Recovery and Life Satisfaction in the First Year After Severe Traumatic Brain Injury: A Prospective Multicenter Study of a Norwegian National Cohort. J Head Trauma Rehabil. 2015;30(4):E38-49.
Lilley EJ, Williams KJ, Schneider EB, Hammouda K, Salim A, Haider AH, et al. Intensity of treatment, end-of-life care, and mortality for older patients with severe traumatic brain injury. The journal of trauma and acute care surgery. 2016;80(6):998-1004.
Mak CH, Wong SK, Wong GK, Ng S, Wang KK, Lam PK, et al. Traumatic Brain Injury in the Elderly: Is it as Bad as we Think? Current translational geriatrics and experimental gerontology reports. 2012;1(3):171-8.
Roe C, Skandsen T, Manskow U, Ader T, Anke A. Mortality and One-Year Functional Outcome in Elderly and Very Old Patients with Severe Traumatic Brain Injuries: Observed and Predicted. Behav Neurol. 2015;2015:845491.
Taussky P, Hidalgo ET, Landolt H, Fandino J. Age and salvageability: analysis of outcome of patients older than 65 years undergoing craniotomy for acute traumatic subdural hematoma. World Neurosurg. 2012;78(3-4):306-11.
Whitmore RG, Thawani JP, Grady MS, Levine JM, Sanborn MR, Stein SC. Is aggressive treatment of traumatic brain injury cost-effective? J Neurosurg. 2012;116(5):1106-13.
Younsi A, Fischer J, Habel C, Riemann L, Scherer M, Unterberg A, et al. Mortality and functional outcome after surgical evacuation of traumatic acute subdural hematomas in octa- and nonagenarians. Eur J Trauma Emerg Surg. 2020.
Skaansar O, Tverdal C, Rønning PA, Skogen K, Brommeland T, Røise O, et al. Traumatic brain injury-the effects of patient age on treatment intensity and mortality. BMC Neurol. 2020;20(1):376.
Dawes AJ, Sacks GD, Cryer HG, Gruen JP, Preston C, Gorospe D, et al. Compliance With Evidence-Based Guidelines and Interhospital Variation in Mortality for Patients With Severe Traumatic Brain Injury. JAMA surgery. 2015;150(10):965-72.
Ronning P, Helseth E, Skaga NO, Stavem K, Langmoen IA. The effect of ICP monitoring in severe traumatic brain injury: a propensity score-weighted and adjusted regression approach. J Neurosurg. 2018:1-9.
Shen L, Wang Z, Su Z, Qiu S, Xu J, Zhou Y, et al. Effects of Intracranial Pressure Monitoring on Mortality in Patients with Severe Traumatic Brain Injury: A Meta-Analysis. PLoS One. 2016;11(12):e0168901.
Chesnut RM, Temkin N, Carney N, Dikmen S, Rondina C, Videtta W, et al. A trial of intracranial-pressure monitoring in traumatic brain injury. N Engl J Med. 2012;367(26):2471-81.
National Institute for Health and Care Excellence. Head injury: assessment and early management (NICE Clinical guideline [CG176]). 2014. https://www.nice.org.uk/guidance/cg176. Accsessed 10 Nov 2020.
Hoffman H, Jalal MS, Chin LS. The Incidence of Meningitis in Patients with Traumatic Brain Injury Undergoing External Ventricular Drain Placement: A Nationwide Inpatient Sample Analysis. Neurocrit Care. 2019;30(3):666-74.
Beer R, Lackner P, Pfausler B, Schmutzhard E. Nosocomial ventriculitis and meningitis in neurocritical care patients. J Neurol. 2008;255(11):1617-24.
Sorinola A, Buki A, Sandor J, Czeiter E. Risk Factors of External Ventricular Drain Infection: Proposing a Model for Future Studies. Front Neurol. 2019;10:226.
Cooper DJ, Rosenfeld JV, Murray L, Arabi YM, Davies AR, D'Urso P, et al. Decompressive craniectomy in diffuse traumatic brain injury. N Engl J Med. 2011;364(16):1493-502.
Hutchinson PJ, Kolias AG, Timofeev IS, Corteen EA, Czosnyka M, Timothy J, et al. Trial of Decompressive Craniectomy for Traumatic Intracranial Hypertension. N Engl J Med. 2016;375(12):1119-30.
Sahuquillo J, Dennis JA. Decompressive craniectomy for the treatment of high intracranial pressure in closed traumatic brain injury. The Cochrane database of systematic reviews. 2019;12(12):CD003983.
Hawryluk GWJ, Rubiano AM, Totten AM, O'Reilly C, Ullman JS, Bratton SL, et al. Guidelines for the Management of Severe Traumatic Brain Injury: 2020 Update of the Decompressive Craniectomy Recommendations. Neurosurgery. 2020;87(3):427-34.
Hutchinson PJ, Kolias AG, Tajsic T, Adeleye A, Aklilu AT, Apriawan T, et al. Consensus statement from the International Consensus Meeting on the Role of Decompressive Craniectomy in the Management of Traumatic Brain Injury : Consensus statement. Acta Neurochir (Wien). 2019;161(7):1261-74.
Regional Committees for Medical and Health Research Ethics. (REC). Examples of avtivities that do not require approval from REC. 2012. https://helseforskning.etikkom.no/reglerogrutiner/soknadsplikt/sokerikkerek?p_dim=34999&_ikbLanguageCode=us. Accessed 6 Jul 2018.

Download PDF

Journal Publication

published 06 Jan, 2022

Read the published version in BMC Emergency Medicine →

Editor assigned by journal
16 May, 2021
Reviewers invited by journal
16 May, 2021
Submission checks completed at journal
03 Apr, 2021
Editor invited by journal
21 Mar, 2021
First submitted to journal
18 Mar, 2021

You are reading this latest preprint version

Incidence of emergency neurosurgical TBI procedures: A population-based study

Status:

Journal Publication

Version 1

Abstract

Background

Methods

Results

Conclusions

Figures

Background

Methods

Statistical analysis

Results

Discussion

Conclusion

Abbreviations

Declarations

Ethics approval and consent to participate

Consent for publication

Availability of data and materials

Competing interests

Funding

Authors’ contribution

Acknowledgements

References

Status:

Journal Publication

Version 1