Most acute SDH are due to trauma from laceration of bridging veins in the subdural space. Nontraumatic cases are rare (incidence rate 3-5%) and predominantly affects adulst in 5th to 7th decade.
Predispoding factors to spontaneous SDH:
- vascular abnormalities – cerebral aneurysm, AVM, dural AVF
- hematological disorders
- anticoagulant therapy
Mechanisms of nontraumatic SDH:
- previous minor hemorrhages fixes an aneursym to local arachnoid adhesions –> results in bleeding directly into subdural space when arachnoid tear occurs after aneurysm rupture
- hemorrhage under high pressure leading to pia arachnoid rupture and extravasation into subdural space
- sudden increase in intravenous pressure (Valsalva) – rupture of bridging dural veins
- intracranial hypotension – systemic vascular hypotension after exercise
- Modality of choice: CT; cerebral angio to exclude vascular abnormalities
- Other investigations: coagulation tests
Wang, Hui Sun, Seok Won Kim, and Sung Hoon Kim. “Spontaneous Chronic Subdural Hematoma In An Adolescent Girl”. J Korean Neurosurg Soc 53.3 (2013): 201. Web.
Elements of the external ventricular drain (EVD) infection control protocol for EVD placement.
- A wide area of the patient’s hair (A) is clipped to an area large enough to eventually dress with a medium-sized transparent dressing film.
- Chlorhexidine-alcohol is then applied in a first skin preparation (A, left).
- Full patient draping is followed by a second chlorhexidine-alcohol skin preparation with the surgeon wearing gown, gloves, cap, and mask (A, center), and full barrier precautions are used throughout (A, right).
- A minocycline/rifampin antibiotic-impregnated EVD catheter is tunneled 3 to 5 cm and then secured with a curvilinear line of surgical staples (B).
- After Benzoin tincture is applied to the skin broadly and allowed to fully dry, a chlorhexidine-eluting patch is applied over the exit site (without wrapping the patch around the catheter), and a medium-sized transparent dressing film is applied (B).
- The borders of the transparent dressing film and the catheter are further secured with adhesive strips (B).
- Additional information on placement and dressing available at: http://www.cleanbrain.org
Elements of the external ventricular drain (EVD) infection control protocol for EVD manipulation (cerebrospinal fluid draws or flushing). Supplies are arranged outside the sterile field (A): 70% isopropyl alcohol, a kidney basin, and several 10- mL vials of sterile, preservative-free normal saline. Supplies are then opened onto a sterile field created with a large sterile drape over the patient (B): several chlorhexidine-alcohol swabs, several sterile 10-mL syringes, a surgical sponge, and sterile Luer-fitting port caps. Before gowning and gloving, the 3-way stopcock on the EVD port is turned to 45 (“off” to all directions) and submerged in 70% isopropyl alcohol solution (C). (This step is not performed on the sterile field.) The intensive care unit (ICU) nurse holds the EVD line over the sterile field without allowing the tubing to contact the field (D), and the physician dons cap, mask, sterile gown, and sterile gloves. The physician then cleanses the entire region of the port with a chlorhexidine-alcohol swab. The old port cap is discarded; the port is inverted; and fluid in the port is shaken out onto a surgical sponge (E). The port is cleaned again and then filled with chlorhexidine-alcohol solution (F). The port is inverted, and chlorhexidine-alcohol solution is shaken out onto the surgical sponge (G). Steps F and G are repeated several times. The physician uses the sterile 10-mL syringes to draw up sterile, preservative-free normal saline in sterile fashion from the ICU nurse. The port is rinsed with sterile, preservative-free normal saline, and the port is inverted to discard (H). The rinse step is repeated several times. A sterile 10-mL syringe is then attached to the port for CSF draw or flushing (I). Additional information about EVD manipulation techniques available at: http://www.cleanbrain.org.
External Ventricular Drain Infection Control Protocol
Flint, Alexander C. et al. “A Simple Protocol To Prevent External Ventricular Drain Infections”.Neurosurgery 72.6 (2013): 993-999. Web.
- Large hemispheric infarction defined as greater than 2/3 vascular territory and/or early signs of shift or impending herniation.
- Cerebellar/posterior fossa infarction with threat of herniation or brainstem compromise
- Cerebral edema requiring hyperosmolar (3% saline) therapy and/or ICP monitoring
- Fluctuating exam suggesting of ongoing ischemia; induced hypertension
- Status post interventional therapy
- 2 Neurovascular-hemorrhagic
- infra- or supra-tentorial spontaneous intracerebral hemorrhages that require ICU admission (refer to ICH Stroke Unit admission guidelines)
- Aneurysmal/non-Aneurysmal subarachnoid hemorrhage
- AVM post intervention/embolization and/or resection
- Non-ruptured aneurysm coiling/clipping
- Patients with abnormal imaging and depressed GCS in setting of traumatic brain injury
- Acute subdural/epidural hemorrhages
- Chronic subdural hemorrhages > 10cm in thickness or <10cm in thickness in presence of neurological symptoms
- Evidence of vasogenic edema, shift with risk of herniation or neurological compromise
- Osmotherapy/ICP monitoring for cerebral edema
- Post-op craniotomy
- Acute cord injury-trauma, malignancy
- Post-operative cervical/thoracic fusion/lami with risk of respiratory decompensation
- Status Epilepticus-convulsive or nonconvulsive
- Neuromuscular disease
- Guillain-Barre with change in VC and or NIF by 30% in a 24-hour period or a VC <20mg/kg or NIF <25cm H20 or evidence of autonomic instability
- Myasthenic crisis
- Neurological patients with evidence of hemodynamic instability requiring vasopressor therapy
- Neurological patients with evidence of respiratory compromise requiring mechanical ventilation
- Neurological patients requiring invasive hemodynamic monitoring
NSUH Guidelines: Neurosurgical Intensive Care Unit Admission Protocol. 11/18/2014
F our different tailored craniotomies are used for typical anterior circulation aneurysms:
- pterional craniotomy for internal carotid aneurysms
- Sylvian craniotomy for middle cerebral aneurysms
- orbitocraniotomy for anterior communicating artery
- anterior interhemispheric craniotomy for A2-callosomarginal artery aneurysms
Two approaches are used for posterior circulation aneurysms:
- lateral paracondylar for vertebral artery aneurysms
- paramedian for peripheral aneurysms
Steiger, Hans-Jakob, Nima Etminan, and Daniel Hänggi. Microsurgical Brain Aneurysms. Print.
SEPS = Subdural Evacuating Port System (Medtronic)
“The SEPS™ Cranial Access Kit is indicated when access to the subdural space and evacuation of a cranial subacute or chronic hematoma or hygroma is necessary. The SEPS Cranial Access Kit consists of surgical instruments and accessories used for draining subdural fluid accumulations such as hygromas and liquid-state subdural hematomas to an external suction reservoir without touching the brain. Utilizing a minimally invasive technique, the SEPS Cranial Access Kit’s components are designed to promote gradual brain re-expansion by creating a low homogeneous negative pressure throughout the subdural space as fluid is drained to an external suction reservoir.”
Instructions for Putting a SEPS drain:
- perform SEPS under local or general anesthesia
- identify area of greatest subdural fluid thickness using CT scan or MRI
- prep and drape selcected site with Chloraprep
- Mark incision site with sterile marking pen
- make a 5 mm incision through skin, subcutaneous tissue, galea and periosteum.
- apply holzheimer retractor to expose skull
- attach safety stop collar to drill bit
- secure drill bit with safety stop collar to hand drill
- place drill into chuck, hold chuck motionless while rotating handle clockwise.
- create twist drill hole through outer and inner tables of the skull
- incise dura, remove all exposed dura and subdural membranes form twist drill hole before inserting evacuating port (use #11 scalpel blade and forceps or unipolar cautery)
- Do not insert evacuating port until fluid is flowing freely from twist drill hole
- remove self-retaining scalp retractor and insert evacuating port by twisting clockwise. (4 turns will seat port securely into skull above inner table.
- evacuating port should never protrude beyond inner table
- attach silicone tubing to evacuating port and to suction reservoir bulb
- apply low homogenous negative pressure with suction reservoir bulb
- close wound around evacuating port
- fluid evacuation generally completed within 24-48h. Monitor suction reservoir blood and empty as needed with repeated reapplication of negative pressure.
The ABCDE Bundle: Tools for Implementation
- “Wake Up and Breathe” Protocol
- Confusion Assessment Method for the ICU (CAM‐ICU) Flowsheet
- Intensive Care Delirium Screening Checklist (ICDSC)
- Pediatric CAM‐ICU – Worksheet for Daily Delirium Assessment
- Progressive Mobility Protocol
- Exercise/Mobility Safety Screen and Therapy
- Journal Club Exercises
“Wake Up and Breathe” Protocol Spontaneous Awakening Trials (SATs) + Spontaneous Breathing Trials (SBTs)
CAM ICU Flowsheet:
http://www.aacn.org/WD/CETests/Media/ABCDE–Tools%20for%20Implementation.pdf ABCDE–Tools for Implementation