Clinical studies have confirmed the safety and effectiveness of hypothermia treatment in comatose patients after cardiopulmonary resuscitation, and its cerebral protective and neurological improvement effects are consistent with the results of animal studies. However, there are more patients in coma after brain injury or spinal cord injury who need clinical studies on hypothermia treatment and enhanced norms of hypothermia treatment.
To this end, the Neurocritical Care Collaborative Group of the Neurology Branch of the Chinese Medical Association conducted a search and review of the literature related to hypothermia in adults (Medline database from 2000-2013), using the 2011 edition of the Oxford Center for Evidence Based Medicine (CEBM) evidence grading criteria for The level of evidence was confirmed and the recommendation was confirmed, and the recommendation level was increased (A recommendation) for those with insufficient evidence for the time being, but with a high level of consensus in the expert discussion.
I. Indications for hypothermia treatment
Hypothermia has been shown to reduce intracranial pressure and neuroprotective effects, and has been confirmed by several clinical trials.
Recommendations.
(1) Hypothermia is recommended for comatose patients after cardiopulmonary resuscitation due to ventricular fibrillation, ventricular tachycardia, or cardiac arrest (Class A recommendation). Patients in coma after cardiopulmonary resuscitation due to non-electric shockable cardioversion may be treated with hypothermia (Class B recommendation).
(2) Patients with large cerebral infarcts in the cerebral hemispheres (≥2/3 of the middle cerebral artery supply area), patients with large supratentorial cerebral hemorrhage (>25 ml), patients with severe craniocerebral trauma (Glasgow Coma Score 3-8, intracranial pressure >20 mmHg; 1 mmHg=0.133 kPa), patients with severe spinal cord trauma (ASIA score A), and patients with refractory continuous status epilepticus due to The exact effect of hypothermia treatment needs to be confirmed by several high-quality clinical studies.
Second, cryotherapy operation specification
1.Cryogenic technology selection
Recommendations.
(1) Priority is given to the new systemic body surface cryogenic technology or intravascular cryogenic technology with temperature feedback control device to carry out cryotherapy. If you do not have the conditions, you can also choose the traditional whole body surface cooling (including ice blankets, ice caps, ice bags) to complete cryotherapy.
(2) Cryogenic techniques with 4°C saline intravenous infusion can be chosen to assist in inducing hypothermia, but be used with caution in patients at risk of cardiac insufficiency and pulmonary edema.
(3) Head surface hypothermia technique can be selected for surgical side hypothermia in patients after partial craniectomy. Combined head and neck hypothermia technique is chosen to reduce brain parenchymal temperature, but blood pressure and intracranial pressure must be monitored.
2.Cryogenic target selection
Recommendation: The cryogenic target temperature of 32-35°C can be selected. Very early cardiopulmonary resuscitation after hypothermia treatment can choose the target temperature of 36 ℃.
3.Cryogenic time window selection
Recommendation: Patients in coma after cardiopulmonary resuscitation should start hypothermia treatment within 6 h. Other patients should also start hypothermia treatment as early as possible (6~72 h), or determine the start time of hypothermia treatment according to the intracranial pressure (>20 mmHg).
4.Length of hypothermia selection
Recommendation: The duration of induction hypothermia should be as short as possible, preferably 2 to 4 h to reach the target temperature. The target hypothermia maintenance length should be at least 24 h, or determined by intracranial pressure (<20 mmHg). The rate of rewarming is actively controlled and slowly reaches normothermia within 6 to 72 h according to the type of disease.
5. Choice of temperature monitoring technique
Recommendation: Bladder or rectal temperature monitoring technique is preferred to take advantage of its non-invasive, easy to operate and closest to brain temperature.
6.The choice of hypothermic chills control
Recommendation.
(1) The degree of chilling should be routinely assessed, and the BSAS can be selected as the assessment scale to guide the implementation of anti-chilling strategies.
(2) Combined anti-chilling regimens such as buspirone (load 30 mg, maintenance 15 mg every 8 hours), pethidine hydrochloride (load 1 mg/kg, maintenance 25-45 mg/h) and midazolam (load 0.1 mg/kg, maintenance 2-6 mg/h) can be selected. When chilling control is unsatisfactory or rapid cooling is required, add vecuronium bromide (loading 0.03-0.05 mg/kg, maintenance 0.02-0.03 mg-kg-1-h-1) or rocuronium bromide (loading 0.6 mg/kg, maintenance 0.3-0.6 mg -kg-1-h-1), etc. Drug dose adjustment must take into account individual differences.
(3) Select active body surface insulation and combine with anti-cold warfare drugs.
Third, hypothermia complication monitoring and management
1.Monitoring of hypothermic complications
Recommendation: Develop a monitoring program according to the common complications during hypothermia treatment, and develop an operation and accident monitoring program according to the selected hypothermia technique.
2.Treatment of cryogenic complications
Recommendation: Judge the complications and their severity according to the monitoring results. Common complications such as hypokalemia, pneumonia, gastrointestinal dysfunction, stress hyperglycemia, hypoproteinemia and deep vein thrombosis of the lower limbs must be actively prevented and treated, and serious and difficult-to-control complications must be rewarmed in advance. Intracranial pressure monitoring must be strengthened during the rewarming process, and the rewarming rate should be adjusted accordingly or surgical measures should be taken to avoid brain herniation.
Prognosis assessment of hypothermia treatment
Recommendation: Short-term (≤1 month) and long-term (≥3 months) prognostic evaluation should be performed after hypothermia treatment, including primary (death rate, neurological disability, quality of life) and secondary (complications, length of stay, hospitalization costs, etc.) indicators.
V. Outlook
Hypothermia is an important treatment for patients with severe brain injury, with a certain effect of reducing intracranial pressure and neuroprotection, and affects the survival rate and quality of life of patients, with promising clinical research and clinical application. The problems that have not been well solved in the process of hypothermia must be continuously improved and perfected.