What is Intrathecal Chemotherapy?

In recent years, intrathecal injection of chemotherapy drugs has become one of the most effective methods for the prevention and treatment of central nervous leukemia (CNS). However, the subsequent toxic effects or complications of the central nervous system bring great pain to patients. We used intrathecal chemotherapy drugs to treat 135 patients with leukemia. After careful care, we reduced the injection process and post-injection complications.

Intrathecal injection is to directly inject the drug into the subarachnoid space through the lumbar puncture, thereby dispersing the drug in the cerebrospinal fluid and quickly reaching an effective blood drug concentration. It is reported that isotope-labeled albumin is injected intrathecally, mostly in It can reach the subarachnoid space at the base of the brain in 4-6 hours, and intrathecal administration can make the drug naturally reach the brain pools of the subarachnoid space with the cerebrospinal fluid circulation and diffuse throughout the ventricle system ^[1] . Short-term repeated administration can maintain a certain effective concentration of the drug, which is a better way of administration and treatment of intracranial infection ^[2] .

Intrathecal administration, without passing through the blood-brain barrier, allows the drug to naturally reach the subarachnoid spaces of the cerebral cisterns with the cerebrospinal fluid circulation, and diffuses throughout the ventricle system. Repeated administration for a short period of time can maintain a certain effective concentration of the drug. Better route of administration and treatment of intracranial infection ^[3] .

Chinese name: Intrathecal injection
Function: Prevention and treatment of central nervous leukemia

Brief introduction: One of the most effective methods
Advantages: Reduced complications during and after injection

Advantages of intrathecal injection

Intrathecal administration can be performed simultaneously with lumbar puncture. Because the drug does not pass through the blood-brain barrier and directly enters the subarachnoid space, the concentration of the drug in the cerebrospinal fluid is high and the effect is good. It is particularly suitable for cases of ventricular inflammation, while avoiding large doses. Adverse effects from intravenous medication. Using multiple subarachnoid rinsing can dilute the thick cerebrospinal fluid to facilitate drainage and reduce the bacterial concentration in the cerebrospinal fluid. At the same time, it can take away necrotic brain tissue, bacteria and their toxins, and reduce infection. Intrathecal injection can quickly disperse the drug in the subarachnoid space and the ventricle, which can locally kill bacteria and reduce arachnoid adhesions. At the same time, it can dynamically observe the changes in cerebrospinal fluid color and perform routine laboratory tests, and can perform simple intracranial Pressure monitoring ^[4] .

Intrathecal injection disadvantages

Most patients need repeated spinal subarachnoid puncture to release cerebrospinal fluid and intrathecal injection to achieve a certain effect. The operation is cumbersome and brings great pain to the patient. At the same time, repeated puncture is likely to cause re-infection. In addition, the unidirectional flow of cerebrospinal fluid restricts intrathecal medications from entering the ventricular system. Some scholars believe that the primary factor for failure of intrathecal injection treatment is the continuous infection of the ventricular system. Bacteria can continue to enter the cerebrospinal fluid and maintain active infection ^[4] .

Intrathecal clinical data

This group of 135 cases, 78 males and 57 females, aged 14 to 59 years. Among them, 65 cases were acute lymphoblastic leukemia (ALL), 54 cases were acute non-lymphocytic leukemia (AML), 6 cases were slow-growth blasts, and 10 cases were CNS. Intrathecal injection was performed in 38 cases, 2 to 5 times in 44 cases, 6 to 10 times in 33 cases, and more than 10 times in 20 cases. The largest number was injected 30 times in 9 years. The observation period is 2 days to 10 years.

Intrathecal injection method

2.1 Preoperative preparation

2.1.1 Do a procaine test.

2.1.2 Prepare sterilized articles and medicines and waist packs required during injection.

2.1.3 Provide necessary psychological care to patients to eliminate their fear.

2.1.4 Location of injection point: Use the intersection of the line connecting the left and right posterior superior spines and the posterior midline as the injection point and mark it.

2.2 Intrathecal injection method

2.2.1 The patient should lie on the lateral side of the pillow, with the back perpendicular to the bed, flexing his head toward the chest, holding his knees with his hands to make it close to the abdomen, and make the spine as far as possible to widen the spinal space and facilitate needle insertion.

2.2.2 Routine skin disinfection. Wear sterile gloves, perforated towels, and expose the puncture site. Local anesthesia was performed from 2 to 4 ml of 1% to 2% procaine from subcutaneous to intervertebral ligament.

2.2.3 Use the left hand to fix the puncture point skin, and the right hand to hold the puncture needle slowly into the spine about 4-6cm. When the needle passes through the ligament and the dura mater, the resistance suddenly disappears. At this time, the needle core can be slowly pulled out. If the cerebrospinal fluid overflows, insert the needle core immediately.

2.2.4 Dilute the prepared intrathecal injection drug with 4ml physiological saline, add 5mg of dexamethasone, connect the syringe immediately after pulling out the needle core, and slowly inject.

2.2.5 After the injection is completed, insert the needle core, pull out the puncture needle, cover the sterile dressing, and fix it with adhesive tape. Ask the patient to lie supine on the pillow for 6 to 8 hours.

2.3 Commonly used drugs and doses Methotrexate: the initial dose is 5mg, and later 7.5-10mg; cytarabine and cyclocytidine: the first dose is 25mg, and thereafter 50mg. Both were used with dexamethasone 5mg. CNS patients are injected twice a week, and once every 4 to 6 weeks after remission and vaccination.

Observation of side effects of intrathecal injection

After intrathecal injection, patients have different side effects due to different conditions, age, gender, drug dilution and formulation. The main side effects of this group of patients after injection are shown in the attached table.

After intrathecal injection of chemotherapy drugs such as methotrexate, cytarabine, and cyclocytidine, patients may experience a series of adverse reactions. During intrathecal injection to 8 hours after surgery, the general symptoms of headache, dizziness, nausea, and vomiting are mild. After symptomatic treatment, they usually disappear within 24 hours, and a few patients can disappear in bed for 2 to 3 days. We observed during observation: due to the rapid bolus injection, the sudden increase in intracranial pressure caused severe meningeal irritation such as headache, nausea, vomiting, and neck rigidity in 4 patients at the same time. Hypertonic glucose solution, pain relief, sedation and other symptoms relieved within a few hours after treatment, and disappeared within 24 hours. When the bolus speed is slowed down (about 15 minutes) and the bolus is drawn while withdrawing, the occurrence of the above symptoms is significantly reduced, and the degree of occurrence is relatively mild. Eight patients with intrathecal injection more than 6 times had lumbago, which was significant when they were active, which was considered to be caused by multiple puncture injuries. In the future, we will use small needles as much as possible according to the patient's weight, age and gender to avoid the occurrence of side effects. Serious complications occurred in 2 cases in this group. Meningeal irritation suddenly worsened with intrathecal injection 6 times in 1 CNS patient, accompanied by fever. Cerebrospinal fluid examination showed a large number of white blood cells, and pseudomonas were cultured. Due to the lack of strict aseptic operation during injection. After using a lot of antibiotics, it returned to normal. In another case, after 7 intrathecal injections and craniocerebral radiotherapy, the disturbance of consciousness worsened, including dementia, ataxia, speech impairment, and mild paralysis of both lower extremities. He died of white matter encephalopathy. From this point of view, taking correct and effective nursing measures can reduce the incidence of side effects and complications.

Intrathecal care

4.1 Close observation of vital signs. Pay attention to the patient's complexion, lips, pupils, etc. after injection. If sweating, nausea, vomiting, cyanosis of lips, large pupils, stiff neck, etc. are found, stop puncturing immediately and take appropriate measures.

4.2 When puncturing, a small puncture needle should be used to avoid drug extravasation and puncture damage. When the needle is inserted into the subcutaneous tissue, the needle is slowly inserted to prevent injury to the cauda equina or blood vessels due to excessive force, causing pain in the lower limbs or cerebrospinal fluid into the blood, which will affect the judgment of the results. The speed of bolus injection should be slow, and the bolus should be drawn while pumping back, so that the cerebrospinal fluid is gradually mixed and diluted with the drug and then slowly injected. And according to the measured cerebrospinal fluid pressure, adjust the bolus dose appropriately. Those with higher intracranial pressure can slowly put 1 ~ 2ml cerebrospinal fluid. After multiple intrathecal injections, intracranial pressure may decrease, and low intracranial pressure dizziness, headache and other discomforts are prone to occur. At this time, 1 to 2 ml of normal saline may be injected to reduce symptoms. Leukemia patients have low resistance and are prone to infection. Therefore, strict aseptic technique must be used during operation.

4.3 Psychological care. The patient's interpretation should be done well before surgery, so that the patient understands that intrathecal injection of chemotherapy drugs can not only prevent CNS, but also maintain efficacy, prolong the remission period of CNS, and effectively cure CNS, so as to obtain the active cooperation of patients. Observe postoperatively, pay more attention to the patient, and relieve the patient's anxiety, tension and fear.

4.4 Prevention of infection and good diet care. During intrathecal injection of chemotherapy drugs, attention should be paid to aseptic operation. Regularly disinfect the ward before and after surgery to keep the room clean, while reducing the number of accompanying staff and limiting visits. Patients are advised to drink more water during chemotherapy, preferably a light liquid diet. In order to avoid the loss of appetite caused by vomiting and nausea after chemotherapy, eat a full breakfast, eat less Chinese food, and postpone dinner for 1-2 hours.

The adoption of the above nursing measures has significantly reduced the incidence of side effects, strengthened the patient's confidence in defeating the disease, and ensured the smooth implementation of the treatment plan.