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Clearance of bloody cerebrospinal fluid in patients with subarachnoid hemorrhage

Clearance of bloody cerebrospinal fluid in patients with subarachnoid hemorrhage. Subarachnoid hemorrhage (SAH) is one of the most common acute cerebrovascular diseases at present. Aneurysm rupture accounts for about 85% of all SAH, with extremely high fatality and disability rates. Studies have shown that a large amount of bloody cerebrospinal fluid and its inflammatory substances in the subarachnoid space are important factors that cause cerebral vasospasm, hydrocephalus, headache, epilepsy and other related complications. CT-Fisher classification is an independent risk factor affecting its prognosis. Early removal of bloody cerebrospinal fluid is critical to the patient’s prognosis.

In the craniotomy aneurysm clipping operation, the arachnoid membrane is gradually cut to fully open the brain cisterns to promote the circulation of the cerebrospinal fluid. At the same time, the cerebrospinal fluid is directly flushed and replaced with normal saline during the operation, which can greatly reduce the bloodiness of the subarachnoid space. Cerebrospinal fluid reduces complications such as cerebral vasospasm. This article summarizes the current research progress of blood cerebrospinal fluid clearance.

1. Lumbar drains (LD)

Since Vourc’h G first introduced lumbar cistern drainage in 1963, lumbar cistern drainage has been widely used in SAH, intracranial infection, and cerebrospinal fluid leakage. The operation is carried out on the basis of lumbar puncture. For patients whose intracranial pressure exceeds 200 mmH2O (1 mmH2O=9.8 Pa), the cerebrospinal fluid is slowly released and the lumbar cistern is inserted. Some researchers used fluid mechanics tools to model and analyze the pressure and blood concentration of the ventricle, subarachnoid space, and lumbar cistern in patients with different drainage rates. Through a series of parameters, it was observed that the lumbar cistern drainage can effectively remove bloody cerebrospinal fluid. High drainage rate leads to higher clearance rate.

A prospective randomized controlled trial in 2018 included a total of 60 patients with aneurysmal subarachnoid hemorrhage (aSAH) who underwent craniotomy aneurysm clipping and were randomly divided into LD and non-LD groups. The incidence of vasospasm and related cerebral infarction was compared, and the status of discharged patients and the follow-up after discharge were compared. The results showed that the incidence of clinical vasospasm and the incidence of spasm-related cerebral infarction were reduced by 33%, and the difference was statistically significant (P <0.05) ).

It further confirmed the positive effect of lumbar cistern drainage to prevent vasospasm and improve the prognosis of patients. A controlled trial and meta-analysis of lumbar cistern drainage in patients with SAH showed that the relative risks of all indicators after lumbar cistern drainage were significantly reduced. Among them, new cerebral infarction decreased by 48%, severe disability decreased by 50%, and mortality A 71% decrease, and a 46% decrease in delayed ischemic neurological dysfunction, with confidence intervals within 95%.

Studies have pointed out that the drainage of lumbar cistern is effective in the removal efficiency of bloody cerebrospinal fluid and the reduction of hydrocephalus, cerebral vasospasm, epilepsy and other related complications. Drainage has the characteristics of continuous, stable, and controllable, compared with ventricular drainage ( External ventricular drainage (EVD) is safe and controllable, while avoiding the pain caused by repeated lumbar punctures.

A prospective study on the drainage of bloody cerebrospinal fluid selected 148 patients with World Federation of Neurosurgery (WFNS) grade III and interventional embolization, and randomly divided them into LD group and EVD group, and analyzed the two groups of cerebral hemorrhage 2 months after the onset , Cerebral vasospasm, intracranial infection, hydrocephalus and prognosis Glasgow Coma Scale (GCS) score, the results showed that compared with the EVD group, the intracranial pressure in the LD group decreased smoothly, with little fluctuation, and the incidence of cerebral hemorrhage was lower , The infection rate and hydrocephalus rate are slightly higher, and the incidence of vasospasm and chronic hydrocephalus is similar.

Lumbar drainage can improve the clinical efficacy of patients with high Fisher scores (levels 3 and 4). However, the lumbar cistern catheterization and drainage operation is difficult, and there are certain risks during the catheterization process and after the operation. During the catheterization process, the release of cerebrospinal fluid is too much and too fast, the intracranial pressure changes too fast, and the imbalance of the intracranial pressure can induce cerebral hernia In the process of catheterization, nerve root damage, drainage tube tip rupture, difficulty in catheterization, etc. may occur.

It has been reported that one case accidentally cut the end of the tube during the extubation process, and part of it remained in the spinal canal, causing chronic infection and leading to the formation of granulomas. Postoperative care was difficult. The drainage tube was blocked and excessive drainage caused low intracranial pressure. , Subdural hematoma or even brain herniation, retrograde intracranial infection and other adverse reactions. Wang Qiangping conducted a meta-analysis of lumbar cistern drainage and lumbar puncture in the treatment of SAH. The results showed that the long-term efficacy, hydrocephalus incidence and mortality of lumbar cistern drainage were better than lumbar puncture, but intracranial infection The rate is significantly higher than that of lumbar puncture.

2. Multiple consecutive lumbar punctures

Lumbar puncture generally chooses daily lumbar puncture from the first day after surgery. The patient adopts a standard position, routinely disinfects, drapes, and local anesthesia, and accurately locates the lumbar intervertebral space. After successful puncture, bloody cerebrospinal fluid can flow out, and intracranial pressure is measured. , Save the specimen, slowly release the cerebrospinal fluid, and fully release the cerebrospinal fluid according to the pressure.

A number of retrospective analyses have found that continuous lumbar puncture to release cerebrospinal fluid is of great significance in alleviating headache symptoms, preventing vasospasm and related delayed ischemic dysfunction. Its operation is simple and can be repeated, which can reduce the difficulty of nursing. Pressure monitoring is more accurate. Compared with lumbar cistern drainage, continuous lumbar puncture can reduce the postoperative infection rate. A clinical study collected 80 SAH patients, 41 cases were enrolled in the lumbar puncture group, 39 cases were enrolled in the lumbar cistern drainage group, the clinical results and complications of the two groups were compared, and the results showed that lumbar cistern drainage had a higher infection rate (P = 0.029) There was no statistically significant difference between the two groups in terms of cerebral hemorrhage, hydrocephalus, cerebral vasospasm, and hospital stay.

However, the intracranial pressure of the lumbar puncture fluctuates greatly. For patients with high intracranial pressure, there is a risk of brain herniation, and the amount of early drainage is limited. Multiple consecutive lumbar punctures are required, which will cause local skin redness and induration, low back pain and other discomforts. , Increase the suffering of patients. Both lumbar cistern drainage and continuous lumbar puncture have advantages and disadvantages in the treatment of SAH. At present, there are few studies on both, and further studies are needed for complications and long-term prognosis. In clinical work, a suitable method can be selected according to the actual situation of the patient and the medical condition.

3. Cerebrospinal fluid replacement

After successful lumbar puncture, measure the intracranial pressure, slowly release 5 mL of cerebrospinal fluid and slowly inject 5 mL of saline. Repeat the above operation, replacing 20-40 mL of cerebrospinal fluid each time, once a day, until the bloody cerebrospinal fluid is basically discharged. Cerebrospinal fluid replacement is based on a lumbar puncture. Intrathecal saline is injected to further dilute the cerebrospinal fluid and reduce the concentration of harmful components. In some cases, intrathecal injection of dexamethasone injection or nimodipine injection can further reduce inflammation and prevent For vasospasm, dexamethasone has the effect of anti-inflammatory and maintaining cell membrane stability, and nimodipine injection has the effect of anti-vasospasm. Xie Zhaotai et al. [Studies have confirmed that dexamethasone combined with cerebrospinal fluid replacement in the treatment of SAH is safe and effective.

Cerebrospinal fluid replacement has the same effect in preventing vasospasm, reducing headaches and improving prognosis. Ding et al. included 79 SAH patients of grade III to IV, of which 42 received aneurysm embolization and cerebrospinal fluid replacement, and 37 received only aneurysm embolization. The treatment effects and complications of the two groups were compared. The results showed that the incidence of cerebral vasospasm and hydrocephalus in patients treated with cerebrospinal fluid replacement was significantly lower than that in the control group, and the difference was statistically significant (P <0.05). At present, related studies have not found that the infection rate of cerebrospinal fluid replacement will increase, but compared with lumbar puncture, the operation time is longer and requires patient cooperation. Repeated operations at the same time will also increase the risk of infection.

SAH, especially patients after craniotomy, have high intracranial pressure and use cerebrospinal fluid replacement, which has a poor effect on lowering intracranial pressure. In terms of the amount of cerebrospinal fluid replacement, unequal amount of cerebrospinal fluid replacement is related to the prognosis of patients. The clinical symptom relief rate of a large number of groups is , The total effective rate of clinical treatment, postoperative complications and hospital stay are better than the small group and the control group. In terms of cerebrospinal fluid replacement, normal saline, dexamethasone, nimodipine injection, fasudil hydrochloride injection and artificial cerebrospinal fluid have all proven safe and effective. There is currently no clear information on the amount of cerebrospinal fluid replacement, replacement frequency, replacement drugs, etc. The definition requires more research.

4. Ventricular drainage

The first use of ventricular drainage dates back to 1973. After more than 40 years of development, it has become one of the most widely used first aid measures in neurosurgery. In acute hydrocephalus, cerebral hemorrhage breaking into the ventricle, increased intracranial pressure and even cerebral herniation Played a huge role in other aspects. Ventricular drainage is mostly used for acute hydrocephalus, rupture of aneurysm into the ventricle and severe SAH after SAH, but it is less used for SAH alone. Ventricular drainage is effective in removing bloody cerebrospinal fluid, reducing intracranial pressure and improving prognosis. A study included 62 patients with high-grade aneurysmal SAH and randomly divided them into two groups. The experimental group was treated with aneurysm clipping and ventricular drainage, and the control group received only aneurysm clipping. The prognosis of the patients was observed 1 year after surgery. The experimental group is better than the control group in terms of the incidence of cerebral vasospasm, hydrocephalus, and cerebral infarction. Combined with ventricular drainage after aneurysm surgery has positive significance in improving the prognosis of patients.

Ventricular hemorrhage is an independent risk factor for secondary hydrocephalus after SAH. The distribution of hemorrhage in the cerebral cistern and the amount of hemorrhage are the key factors for secondary hydrocephalus after SAH. In particular, the clearance rate of basal cistern blood cerebrospinal fluid can be used as a postoperative prediction An important factor in hydrocephalus. Clearing the cisternal hemorrhage as soon as possible and improving the removal efficiency can reduce the incidence of complications. Although the extraventricular drainage tube has a large diameter, a fast cerebrospinal fluid flow rate and a high drainage efficiency, it does not increase the clearance efficiency of subarachnoid blood clots.

Some scholars have conducted a study on the blood clot clearance rate of SAH patients using lumbar cistern drainage and ventricular drainage after interventional embolization. 4 to 5 days after the onset of SAH, the cerebrospinal fluid hemoglobin (Hb) in the lumbar cistern drainage group ) Level increased, but the Hb level was higher in the 8-9 d ventricular drainage group, indicating that the lumbar cistern drainage can accelerate the clearance of blood clots than the ventricular drainage, which may be related to the bleeding in the subarachnoid space and cerebrospinal fluid Hemodynamics is related.

The longer the drainage outside the ventricle, the higher the risk of infection. There is a certain degree of difficulty in the operation of outside ventricular drainage, which requires an experienced doctor to operate it, and it is risky. Repeated puncture may cause new intracranial hematoma. Postoperative care is difficult, increasing the risk of infection and the risk of excessive cerebrospinal fluid drainage. There are fewer applications of ventricular drainage and related studies. It is rarely used for SAH alone, but for patients with intracranial infection and ventricular empyema, ventricular drainage is a better choice.

5. Cerebrospinal fluid purification system

With the development of biomedical engineering and the integration of disciplines, cerebrospinal fluid replacement and filtration devices have been continuously developed. The higher drainage cerebrospinal fluid purification system can greatly reduce blood clots in the subarachnoid space. It depends on external pumps to assist drainage and cerebrospinal fluid. Circulation can speed up the removal of blood and debris and reduce the potential risk of vasospasm. In 2011, Niu Songtao and others conducted the first in vitro purification test using the internationally pioneered cerebrospinal fluid purification system. This system uses the principle of hemodialysis to purify bloody cerebrospinal fluid quantitatively and at a constant rate, and conduct real-time intracranial pressure monitoring, which can effectively remove large Some red blood cells and their lysates have not yet entered clinical trials.

At present, the fastest progress is the American NeurapheresisTM system, which also uses the principle of hemodialysis. The influence of the NeurapheresisTM system on intrathecal cerebrospinal fluid dynamics has been calculated through the establishment of a fluid dynamics model. Even if the flow rate is the largest, the dynamics of the cerebrospinal fluid can be kept stable. This is the next step Clinical trials provide a reliable theoretical basis. The system conducted the first prospective clinical trial in 2018 and has been clinically reported. The study selected 13 patients with SAH after aneurysm clipping and received cerebrospinal fluid filtration for up to 24 hours, every 2 h Perform a neurological examination and collect samples of cerebrospinal fluid, and perform CT scans before and after filtration. The results showed that the blood volume of the brain cistern was significantly reduced, and the average Hijdra score was reduced by 46.5%.

The Neurapheresis TM system can effectively filter blood cerebrospinal fluid, with safety and feasibility, which further proves that the system can safely filter cerebrospinal fluid and has the potential to remove blood and blood by-products. However, there are fewer clinical trial samples, and the safety and effectiveness of the system needs more clinical trial verification. Based on the advantages of simplicity, efficiency, safety, reliability, and continuous monitoring, it has a good application prospect in the future.

6. Summary

In summary, the bloody cerebrospinal fluid of SAH seriously affects the prognosis of patients. Therefore, it is necessary to remove bloody cerebrospinal fluid as soon as possible. The above methods are effective in removing bloody cerebrospinal fluid, metabolites and inflammatory substances, and stabilize the physical and chemical properties of cerebrospinal fluid. Ingredients, reduce intracranial pressure, improve cerebrospinal fluid dynamics, and prevent complications such as cerebral vasospasm and hydrocephalus. The drainage method of SAH bloody cerebrospinal fluid can be selected according to medical conditions and the specific conditions of the patient.