Comment on: The association of bispectral index values and metrics of cerebral perfusion during cardiopulmonary bypass

Cardiopulmonary bypass (CPB) merupakan alat penunjang fungsi sirkulasi dan pernapasan pasien yang biasa digunakan ketika menjalani pembedahan jantung atau pembuluh darah besar. Selama prosedur CPB, kondisi hipotermia dipertahankan untuk menurunkan kebutuhan oksigen dan laju metabolisme. Kondisi hipotermia akan mempengaruhi keseimbangan asam-basa pada tubuh. Manajemen asam-basa selama prosedur CPB dicapai dengan menggunakan metode a-stat atau pH-stat. Pada metode a-stat, manajemen asam-basa dilakukan dengan menjaga pHa 7.4 dan PaCO2 40 mmHg pada suhu 37oC tanpa penambahan CO2 oksigen untuk menjaga total CO2 tetap konstan. Sedangkan, pada metode pH-stat, diberikan CO2 oksigen untuk menjaga PaCO2 40 mmHg dan pHa 7.4 secara in vivo. Masih banyak perdebatan terkait waktu penerapan masing-masing metode. Pada level mikrosirkulasi, manajemen a-stat terbukti memberikan keuntungan pada otak dan mengurangi insidensi postoperative cerebral dysfunction. Sedangkan, metode pH-stat dilaporkan meningkatkan risiko emboli otak, sehingga tidak disarankan untuk pasien yang memiliki risiko tinggi gangguan aliran darah otak. Namun, terdapat pula laporan yang menyatakan pH-stat bermanfaat pada operasi bedah jantung anak. Berdasarkan hal itu, usia pasien dapat menentukan waktu penggunaan metode a-stat dan pH-stat. Satu indikasi primer penggunaan pH-stat adalah selama proses pendinginan saat deep hypothermic circulatory arrest (DHCA), sedangkan metode a-stat lebih baik digunakan selama selective cerebral perfusion (SCP) dan rewarming.

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Transcranial Doppler in the Study of Cerebral Perfusion During Cardiopulmonary Bypass

Transcranial Doppler Sonography ◽

10.1007/978-3-7091-8864-4_11 ◽

1986 ◽

pp. 164-172

Author(s):

T. Lundar

Keyword(s):

Cardiopulmonary Bypass ◽

Transcranial Doppler ◽

Cerebral Perfusion

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The effect of hypothermia during cardiopulmonary bypass on three electro-encephalographic indices assessing analgesia and hypnosis during anesthesia: consciousness index, nociception index, and bispectral index

Perfusion ◽

10.1177/0267659119864821 ◽

2019 ◽

Vol 35 (2) ◽

pp. 154-162

Author(s):

Xiaohua Wang ◽

Jinfeng Zhang ◽

Kunpeng Feng ◽

Yu Yang ◽

Wenwei Qi ◽

...

Keyword(s):

Cardiopulmonary Bypass ◽

Bispectral Index ◽

Artery Bypass ◽

Bypass Graft ◽

Clinical Signs ◽

Induced Hypothermia ◽

Subsequent Increase ◽

Important Means ◽

Pump Coronary Artery Bypass ◽

Low Sensitivity

The depth of anesthesia is commonly assessed in clinical practice by the patient’s clinical signs. However, during cardiopulmonary bypass and hypothermia, common symptoms of nociception such as tachycardia, hypertension, sweating, or movement have low sensitivity and specificity in the description of the patient nociception and hypnosis, in particular, detecting nociceptive stimuli. Better monitoring of the depth of analgesia during hypothermia under cardiopulmonary bypass will avoid underdosage or overdosage of analgesia, especially opioids. Induced hypothermia has a multifactorial effect on the level of analgesia and hypnosis. Thermoregulatory processes appear essential for the activation of analgesic mechanisms, ranging from a physiological strong negative affiliation between nerve conduction velocity and temperature, until significant repercussions on the pharmacological dynamics of the analgesic drugs, the latter decreasing the clearance rate with a subsequent increase in the effect-site concentrations. Under the hypothesis that deep hypothermia induces massive effects on the analgesia and hypnosis levels of the patient, we studied whether hypothermia effects were mirrored by several neuromonitoring indices: two hypnosis indices, consciousness index and bispectral index, and a novel nociception index designed to evaluate the analgesic depth. In this clinical trial, 39 patients were monitored during general anesthesia with coronary atherosclerosis cardiopathy who were elective for on-pump coronary artery bypass graft surgery under hypothermia. The changes and correlation between the consciousness index, bispectral index, and nociception index with respect to the temperature were compared in different timepoints at basic state, during cardiopulmonary bypass and after cardiopulmonary bypass. While the three neuromonitoring indices showed significant correlations with respect to the temperature, the nociception index and consciousness index showed the strongest sensitivities, indicating that these two indices could be an important means of intraoperative neuromonitoring during induced hypothermia under cardiopulmonary bypass.

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Impact of Bispectral Index Monitoring on Propofol Administration in Patients Undergoing Cardiopulmonary Bypass

Anaesthesia and Intensive Care ◽

10.1177/0310057x0703500304 ◽

2007 ◽

Vol 35 (3) ◽

pp. 342-347 ◽

Cited By ~ 10

Author(s):

C. L. Chiu ◽

G. Ong ◽

A. A. Majid

Keyword(s):

Cardiac Surgery ◽

Cardiopulmonary Bypass ◽

Bispectral Index ◽

Standard Dose ◽

Controlled Trial ◽

Target Concentration ◽

Hypothermic Cardiopulmonary Bypass ◽

Bispectral Index Monitoring ◽

Group B ◽

Index Value

Propofol anaesthesia using target control infusion during cardiac surgery has become more popular recently. However, without depth of anaesthesia monitoring, the standard target concentration used may be higher than necessary to maintain adequate hypnosis during hypothermic cardiopulmonary bypass. The purpose of this study was to evaluate the effect of bispectral index monitoring on propofol administration during hypothermic cardiopulmonary bypass. After ethics committee approval and written informed consent, 20 New York Heart Association class I-III patients scheduled for elective cardiac surgery requiring hypothermic cardiopulmonary bypass were studied in this prospective randomised controlled trial. In group C, routine anaesthesia was practised, where patients received propofol at target concentration between 1.5 to 2.5 μ/ml during cardiopulmonary bypass. In group B, the target concentration was titrated to a bispectral index value of 40 to 50. Mean arterial pressure and bispectral index were recorded at various time intervals. The use of propofol, phenylephrine, sodium nitroprusside and adrenaline were recorded. The median propofol administration in group B was significantly less than that in group C (2.9 mg/kg/h compared to 6.0 mg/kg/h). The bispectral index value during bypass was significantly lower in group C than in group B, reflecting a deeper state of anaesthesia. There was no difference in the use of inotropes, vasoconstrictors or vasodilators. Bispectral index monitoring enables a 50% reduction in propofol administration at this standard dose during hypothermic cardiopulmonary bypass.

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