Clinical significance of acute traumatic intracranial pneumocephalus

Systematic review of non-invasive ventilation and craniofacial fractures: a multidisciplinary perspective and recommendations for management

The anatomically complex craniofacial skeleton demands special consideration when caring for cases of polytrauma or medically compromised patients with craniofacial fractures. This paper utilises a systematic review and multidisciplinary opinions to create an algorithm for the hospital-based care of patients with craniofacial fractures (base of skull, orbit, paranasal sinus, and mandible) who require non-invasive ventilation (NIV). Each fracture location has a unique predisposition to a different type of emphysema and associated morbidity. The risk of developing emphysema, combined with its potential severity, is stratified against the harm of not providing NIV for the holistic care of the patient. The aim of this paper is to synthesise evidence from a systematic review of existing literature with multidisciplinary opinions to develop a concise algorithm that outlines the optimal treatment of patients with craniofacial fractures who require NIV.

Clinical Significance of Pneumocephalus in Pediatric Mild Traumatic Brain Injury

OBJECTIVES

Mild traumatic brain injury (mTBI) comprises most (70%-90%) of all pediatric head trauma cases seeking emergency care. Although most mTBI cases have normal initial head computed tomography scan, a considerable portion of the cases have intracranial imaging abnormalities on computed tomography scan. Whereas other intracranial pathological findings have been extensively studied, little is known about the clinical significance of pneumocephalus in pediatric mTBI.

METHODS

We retrospectively identified pediatric mTBI patients with pneumocephalus using the institutional database of a large regional trauma referral center. Outcome measures were defined as clinically important TBI (ciTBI), hospitalization, intensive care unit (ICU) admission, and neurosurgical intervention. Comparisons were made between pneumocephalus and control (isolated linear fracture) groups as well as between isolated (only linear fracture and pneumocephalus) and nonisolated pneumocephalus (pneumocephalus and TBI) groups.

RESULTS

Among 3524 pediatric mTBI cases, 43 cases had pneumocephalus (1.2%). Twenty-one cases (48.8%) had isolated pneumocephalus. The pneumocephalus group had higher rates of ciTBI, hospital admission, ICU admission, and neurosurgery when compared with the isolated linear fracture (control) group. The isolated pneumocephalus group had fewer ciTBI (21.1% vs 70%, P = 0.002), fewer hospitalization (23.8% vs 81.8%, P < 0.001), but similar ICU admission rates (4.8% vs 22.7%, P = 0.089) and length of hospital stay (4.0 ± 2.7 vs 3.6 ± 2.4 days, P = 0.798) in comparison to the nonisolated pneumocephalus group. None of the patients in the isolated group had neurosurgery whereas 2 patients in the nonisolated pneumocephalus group underwent surgery. Multivariable analysis revealed pneumocephalus as an independent predictor of ciTBI and hospital admission, but not ICU admission or neurosurgical intervention.

CONCLUSION

Pneumocephalus is associated with increased rates of hospitalization and ciTBI, but not ICU admission, unfavorable outcome, or neurosurgical intervention in pediatric mTBI. Although usually spontaneously resolving pathology, it may occasionally be linked with complications such as cerebrospinal fluid leakage, meningitis, and tension pneumocephalus. Therefore, careful evaluation, close observation, and early detection of complications may prevent adverse outcomes.

Unusual Presentation of Pneumocephalus With Late Onset During Labour Epidural Analgesia

A 36-year-old woman with no significant medical history was in active labour and requested labour analgesia. While the epidural technique was performed at the L4-L5 interspace, using the loss of resistance to air technique (LORA), inadvertent dural puncture occurred. Since the patient reported no headache or discomfort, the same procedure was repeated at the L3-L4 interspace successfully. Loss of resistance was reported at 3 cm and the epidural catheter was advanced uneventfully at 8 cm. Aspiration was negative for blood or cerebrospinal fluid (CSF) and a test dose of 2 ml lidocaine 2% was administered epidurally. Within five minutes the patient exhibited a mild hypotensive episode successfully treated with 2.5 mg ephedrine IV, a sensory blockade up to T6 level, and a motor blockade up to T10 level. Both the woman's and the baby's vital signs remained stable, no further drugs were administered epidurally and labour progressed painlessly and uncomplicated for 90 minutes with subsequent vaginal delivery of a healthy newborn. During the episiotomy incision repair, the patient complained of light dizziness and nausea. Her vital signs and the arterial blood gases (ABGs) ordered were within normal range, but the neurological examination revealed an isolated Babinski on the right foot. The head CT scan requested indicated a considerable quantity of air within the subarachnoid region. The patient was treated conservatively; symptoms showed steady improvement with total resolution on the sixth day, and the woman was discharged. This case reemphasizes the possibility of pneumocephalus, which may, in reality, occur more frequently than is commonly recognized without a CT confirmation.

A Case of Traumatic Pneumocephalus on the Opposite Side of the Injury Site

Pneumocephalus is defined as an abnormal presence of intracranial air or gas. Traumatic pneumocephalus (TP) typically occurs on the injured side and is in communication with the external environment. This report presented an extremely rare case of TP that occurred on the opposite side of the injured site, even with the absence of any traumatic injury. The patient sustained injuries, including linear skull fracture, acute epidural hematoma, fractures in the clavicle and scapula, and subcutaneous emphysema, on the left side of the body. However, TP occurred on the right side. Although the exact underlying pathogenic mechanism remains unclear, the condition might be attributed to the migration of air bubbles or negative pressure on the opposite side caused by side-to-side closed head injury.

Clinical and Radiological Characteristics of Traumatic Pneumocephalus after Traumatic Brain Injury

Objective

Traumatic pneumocephalus (TP) is a common complication of traumatic brain injury (TBI), which is characterized by the abnormal entrapment of air in the intracranial cavity after TBI to the meninges. The purpose of this study was to investigate the clinical and radiological characteristics related to TP associated with TBI.

Methods

From January 2013 to March 2018, the data from 71 patients with TP after TBI were collected. Demographic and clinical characteristics were investigated and the distribution of TP was investigated as radiological characteristics. The author compared the demographic characteristics of TP to the data from the Korean Neurotrauma Data Bank System (KNTDBS).

Results

There was a higher ratio of males in patients with TP compared with KNTDBS. The mean age was 48.4±20.5 years and the incidence was highest in those 41-60 years of age (42.3%). Surgical treatment was performed in 23.9% patients. The mortality associated with the TP was 4.2%. The most common cause of injury was a traffic accident (52.1%). TP was mainly located in the epidural space (53.5%) and showed a scatter pattern (60.6%). It was mostly located in the frontal and temporal area (81.7%). Skull fractures were observed in 40.8% in the temporal bone and 25.4% in the frontal bone.

Conclusion

The author identified epidemiology, clinical, and radiological characteristics of TP associated with TBI. Although this study has many limitations, the author believes it is worthwhile as it examines various characteristics of TP, which previously had relatively little clinical interest.

Significance of intracranial gas on post-mortem computed tomography in traumatic cases in the context of medico-legal opinions

The detection of intracranial gas (ICG) in people who died due to trauma became possible once postmortem computed tomography (PMCT) became available in addition to traditional post-mortem examinations. The aim of this study was to determine the importance of ICG in the context of medico-legal opinions. We assessed 159 cases of trauma-induced death. Cadavers with pronounced signs of decomposition, open skull fractures, and after neurosurgical operations were excluded. Both PMCT findings and data from autopsy reports were analyzed. ICG was found in 38.99% (n = 62) of the cadavers, 96.77% (n = 60) of which presented with pneumocephalus (PNC) and 40.23% (n = 25) with intravascular gas (IVG). There was a strong correlation between ICG and skull fractures/brain injuries, as well as chest injuries, especially lung injuries. In 13 cases, ICG presented without skull fractures; three of these cases died as a result of stab and incised wounds to the neck and chest. The mean time between trauma and death was significantly longer in the non-ICG group than the ICG group at 2.94 days (0–48 days) and 0.01 day (0–1 day), respectively (p < 0.0001). The presence of ICG is a result of severe neck and chest injuries, including stab and incised wounds. The victims die in a very short amount of time after suffering trauma resulting in ICG. The ability to demonstrate ICG on PMCT scans can be of significance in forming medico-legal opinions.

Acute Outcomes of Isolated Pneumocephali in Children After Minor Blunt Head Trauma

OBJECTIVES

We aimed to determine the prevalence of and adverse outcomes caused by pneumocephali in children with minor blunt head trauma who had no other intracranial injuries (ie, isolated pneumocephali).

METHODS

We conducted a secondary analysis of a public use dataset from a multicenter prospective study of pediatric minor head trauma. We included children younger than 18 years with Glasgow Coma Scale (GCS) scores of 14 or 15 and non-trivial mechanisms of injury who had cranial computed tomographies obtained. Patients with isolated pneumocephali were those without other traumatic brain injuries (TBIs) but could have non-depressed or basilar skull fractures (BSFs). We defined adverse outcomes as death, need for neurosurgery, or intubation more than 24 hours for TBI.

RESULTS

Pneumocephali occurred in 148 (1.0%; 95% confidence interval, 0.8%-1.2%) of 14,983 patients; 54 (36.5%) of 148 were isolated. Of these 54 patients, 42 (77.8%) had associated BSFs (7 of whom also had linear skull fractures) and 8 (14.8%) had associated linear skull fractures without BSFs; 4 patients (7.4%) had no fractures. Thirty-three patients (61.1%) had both GCS scores of 15 and no other signs of altered mental status. All patients with isolated pneumocephali and available descriptive data (n = 26) had small-sized pneumocephali. There were no deaths, neurosurgical interventions, or intubations for more than 24 hours for TBI (95% confidence interval for any of the outcomes, 0%-7.9%) in the 54 patients with isolated pneumocephali.

CONCLUSIONS

Children with isolated pneumocephali and GCS scores of 14 or 15 after minor blunt head trauma are unlikely to have adverse clinical outcomes.

Traumatic pneumocephaly: trapped air from where?

Traumatic pneumocephaly is literally defined as 'air in the head' after trauma. While this phenomenon has been well described in the literature, our case report is unique in describing diffuse pneumocephalus in the subaponeurotic space, subdural space, subarachnoid space, brain and ventricles without a break in the cranial vault: a 26-year-old man fell from a =9 meter scaffolding in a water tower. Following an arduous and delayed extrication, the patient was unresponsive with loss of pulse requiring intubation, cardiopulmonary resuscitation and release of tension pneumothorax with bilateral thoracostomy tubes. Examination remained poor with a Glasgow Coma Scale of 3. Immediate exploratory laparotomy was performed for a small right retroperitoneal haematoma on Focused Assessment with Sonography for Trauma. Postoperative imaging revealed diffuse pneumocephaly without facial fractures. This case presentation explores unusual causes of fistulous connections with the atmosphere that may lead to air trapped in and around the cranial vault.

Traumatic tension pneumocephalus - Two cases and comprehensive review of literature

Although traumatic pneumocephalus is not uncommon, it rarely evolves into tension pneumocephalus (TP). Characterized by the presence of increasing amounts of intracranial air and concurrent appearance or worsening neurological symptoms, TP can be devastating if not recognized and treated promptly. We present two cases of traumatic TP and a concise review of literature on this topic. Two cases of traumatic TP are presented. In addition, a literature search revealed 20 additional cases, of which 18 had sufficient information for inclusion. Literature cases were combined with the 2 reported cases and analyzed for demographics, mechanism of injury, symptoms, time to presentation (acute <72 h; delayed >72 h), diagnostic/treatment modalities, and outcomes. Twenty cases were analyzed (17 males, 3 females, median age 26, range 8–92 years). Presentation was acute in 13/20 and delayed in 7/20 patients. Injury mechanisms included motor vehicle collisions (6/20), assault/blunt trauma to the craniofacial area (5), falls (4), and motorcycle/ bicycle crashes (3). Common presentations included depressed mental status (10/20), cerebrospinal fluid rhinorrhea (9), headache (8), and loss of consciousness (6). Computed tomography (CT) was utilized in 19/20 patients. Common underlying injuries were frontal bone/sinus fracture (9/20) and ethmoid fracture (5). Intracranial hemorrhage was seen in 5/20 patients and brain contusions in 4/20 patients. Nonoperative management was utilized in 6/20 patients. Procedural approaches included craniotomy (11/20), emergency burr hole (4), endoscopy (2), and ventriculostomy (2). Most patients responded to initial treatment (19/20). One early and one delayed death were reported. Traumatic TP is rare, tends to be associated with severe craniofacial injuries, and can occur following both blunt and penetrating injury. Early recognition and high index of clinical suspicion are important. Appropriate treatment results in improvement in vast majority of cases. CT scan is the diagnostic modality of choice for TP.

UR. Delayed neurological deterioration due to progressive pneumocephalus

Pneumocephalus can develop immediately following head trauma or clinical presentation may be delayed for days. We report a case of 35 year male whose initial CT scan brain plain small specks of pneumocephalus in left para-sellar region. However the next day he was complaining of severe headache and had multiple episodes of vomiting. Repeat CT scan showed increase in the size of pneumocephalus including appearance of intraventricular air with mild cerebral edema. The patient recovered well with conservative management. The present case is a gentle reminder that in a subgroup of head injury patients, intracranial air can produce significant mass effect leading to tension pneumocephalus which can can behave like other intracranial mass lesions and causes worsening of the neurological status of these patients.

Pneumocephalus patterns following endonasal endoscopic skull base surgery as predictors of postoperative CSF leaks

OBJECTIVES

Postoperative pneumocephalus is a common occurrence after endoscopic endonasal skull base surgery (ESBS). The risk of cerebrospinal fluid (CSF) leaks can be high and the presence of postoperative pneumocephalus associated with serosanguineous nasal drainage may raise suspicion for a CSF leak. The authors hypothesized that specific patterns of pneumocephalus on postoperative imaging could be predictive of CSF leaks. Identification of these patterns could guide the postoperative management of patients undergoing ESBS.

METHODS

The authors queried a prospectively acquired database of 526 consecutive ESBS cases at a single center between December 1, 2003, and May 31, 2012, and identified 258 patients with an intraoperative CSF leak documented using intrathecal fluorescein. Postoperative CT and MRI scans obtained within 1-10 days were examined and pneumocephalus was graded based on location and amount. A discrete 0-4 scale was used to classify pneumocephalus patterns based on size and morphology. Pneumocephalus was correlated with the surgical approach, histopathological diagnosis, and presence of a postoperative CSF leak.

RESULTS

The mean follow-up duration was 56.7 months. Of the 258 patients, 102 (39.5%) demonstrated pneumocephalus on postoperative imaging. The most frequent location of pneumocephalus was frontal (73 [71.5%] of 102), intraventricular (34 [33.3%]), and convexity (22 [21.6%]). Patients with craniopharyngioma (27 [87%] of 31) and meningioma (23 [68%] of 34) had the highest incidence of postoperative pneumocephalus compared with patients with pituitary adenomas (29 [20.6%] of 141) (p < 0.0001). The incidence of pneumocephalus was higher with transcribriform and transethmoidal approaches (8 of [73%] 11) than with a transsellar approach (9 of [7%] 131). There were 15 (5.8%) of 258 cases of postoperative CSF leak, of which 10 (66.7%) had pneumocephalus, compared with 92 (38%) of 243 patients without a postoperative CSF leak (OR 3.3, p = 0.027). Pneumocephalus located in the convexity, interhemispheric fissure, sellar region, parasellar region, and perimesencephalic region was significantly correlated with a postoperative CSF leak (OR 4.9, p = 0.006) and was therefore termed "suspicious" pneumocephalus. In contrast, frontal or intraventricular pneumocephalus was not correlated with postoperative CSF leak (not significant) and was defined as "benign" pneumocephalus. The amount of convexity pneumocephalus (p = 0.002), interhemispheric pneumocephalus (p = 0.005), and parasellar pneumocephalus (p = 0.007) (determined using a scale score of 0-4) was also significantly related to postoperative CSF leaks. Using a series of permutation-based multivariate analyses, the authors established that a model containing the learning curve, the transclival/transcavernous approach, and the presence of "suspicious" pneumocephalus provides the best overall prediction for postoperative CSF leaks.

CONCLUSIONS

Postoperative pneumocephalus is much more common following extended approaches than following transsellar surgery. Merely the presence of pneumocephalus, particularly in the frontal or intraventricular locations, is not necessarily associated with a postoperative CSF leak. A "suspicious" pattern of air, namely pneumocephalus in the convexity, interhemispheric fissure, sella, parasellar, or perimesencephalic locations, is significantly associated with a postoperative CSF leak. The presence and the score of "suspicious" pneumocephalus on postoperative imaging, in conjunction with the learning curve and the type of endoscopic approach, provide the best predictive model for postoperative CSF leaks.

Traumatic tension pneumocephalus after blunt head trauma and positive pressure ventilation

Pneumocephalus following head trauma is relatively rare, with tension pneumocephalus occurring in an even smaller group of patients. This review presents a recent case of tension pneumocephalus following the use of a manually operated bag-valve-mask to assist ventilations prior to rapid-sequence intubation. A discussion of this case in terms of other reported cases of pneumocephalus after oxygen therapy follows. A limited number of current case reports identified in the literature indicate a connection between pneumocephalus and positive pressure ventilation following blunt trauma. Continuous positive airway pressure (CPAP) ventilation use in patients with an undiagnosed skull fracture is the most common reported cause of ventilation-related pneumocephalus. The case review presented here identifies the use of a bag-valve-mask prior to intubation as a possible contributory cause of the tension pneumocephalus. With only one prior case reported in the literature of pneumocephalus following the use of a bag-valve-mask, this case is unique and may indicate the need for additional awareness for this rare complication. The prehospital diagnosis of pneumocephalus is difficult, as the symptoms and mechanism of injury mimic those associated with intracranial hemorrhage. The use of mannitol in the prehospital treatment of this patient and subsequent improvement in pupillary response may indicate that mannitol has a role in the treatment of tension pneumocephalus when neurosurgical services are not readily available. Additional research is needed to better understand the benefits and risks associated with this treatment modality.

Positive End-expiratory Pressure Reduces Pneumocephalus in Spinal Intradural Tumor Surgery

We tested the hypothesis that 5 cm H2O of positive end-expiratory pressure (PEEP) reduces the incidence of pneumocephalus in patients who undergo spinal intradural tumor surgery. Fifty-three ASA I to III patients who underwent thoracolumbar intradural tumor surgery between the years 2003 and 2006 were included in this study. All patients received propofol, fentanyl, and cisatracurium for induction of the anesthesia. Maintenance was provided by propofol infusion and, oxygen (50%) and air (50%). Group I (n=28) did not receive PEEP whereas group II (n=25) received PEEP as 5 cm H2O. Cranial computerized tomography was taken at 8 hours after the surgery and cases were evaluated for pneumocephalus using BAB Bs200ProP Image System software. Pneumocephalus areas between 0.03 and 4.24 cm2 were observed in 9 patients, 8 in group I and 1 patient in group II at the 8th postoperative hour, at various localizations. There were no neurologic findings in other patients except for 2 patients in group I who presented with headache and mental status change. Although the cerebrospinal fluid leakage is minimal, N2O is not used and the patients are well hydrated, pneumocephalus with neurologic deficits may occur in patients undergoing microsurgical spinal intradural tumor surgery in prone position. In our study, we showed that using 5 cm H2O PEEP perioperatively reduced the risk of pneumocephalus. However, more cases must be studied to support this hypothesis.