Teruyuki Hiraki

Cuff occlusion on the left upper arm increases flow of the left internal mammary artery and bypass flow to the left anterior descending artery

PurposeChanges in vascular resistance in the left forearm may affect the flow of left internal mammary artery (LIMA)- to left anterior descending artery (LADA) bypass, because the LIMA is a major branch of the subclavian artery. We studied the effects of occlusion of the left upper arm on blood flow of LIMA-to-LADA bypass in patients undergoing coronary artery bypass grafting (CABG).MethodsIn ten patients, the blood volume shed from LIMA with the distal end open (LIMA free flow) was stored for 1 min before and during cuff inflation in CABG surgery. LIMA-LADA bypass flow was measured with ultrasonic flow-metry before and after cuff inflation on the left upper arm in an other ten patients. Mean arterial blood pressure (MAP), heart rate (HR), and electrocardiograms (ECGs) were monitored throughout the studies.ResultsLIMA free flow (ml·min−1) increased from 50.3 ± 7.1 to 60.9 ± 8.4 (P < 0.01) at the end of 1-min cuff inflation. LIMA-LADA bypass flow (ml·min−1) increased from 31.4 ± 3.7 to 39.7 ± 4.0 (P § 0.05) at 1 min after cuff inflation. MAP, HR, and ST segments on ECGs did not show any significant changes related to measurement times.ConclusionLIMA-LADA bypass flow increased after cuff inflation on the left upper arm and returned to the baseline values after cuff deflation. Anesthesiologists should be aware of this relationship between local vascular resistance and bypass flow for the evaluation of LIMA-LADA anastomosis.

The use of amplitude-integrated electroencephalography combined with continuous conventional electroencephalography during therapeutic hypothermia for an infant with postnatal cardiac arrest

IntroductionAmplitude-integrated electroencephalography (aEEG) has been employed in therapeutic hypothermia (TH) trials of neonates after perinatal hypoxic-ischemic encephalopathy (HIE). We present a case report involving the use of aEEG during TH with continuous conventional electroencephalography (cEEG) for an infant who experienced postnatal intraoperative cardiac arrest.Case descriptionA five-month-old infant developed cardiac arrest during operation. Return of spontaneous circulation was achieved after one hour of cardiopulmonary resuscitation. Therapeutic hypothermia was applied with neuromuscular blockades. During the TH, the brain function and seizures were monitored with aEEG, which can also display continuous cEEG. Intermittent and discrete seizures were detected on aEEG and confirmed with raw cEEG during the TH and rewarming periods. Several kinds of antiepileptic drugs (AEDs) were administered to manage seizures according to the findings of aEEG with cEEG. Seizures were controlled by the treatments, and she showed no clinical seizures after TH and AED discontinuation.Discussion and evaluation, conclusionsThis case indicated the possibility that the use of aEEG with continuous cEEG for a postnatal infant after cardiac arrest was feasible to detect and assess seizures and the effects of antiepileptic therapy while undergoing TH.

Role of Jugular Venous Oxygen Saturation in Neuroanesthesia

Although it is difficult to directly evaluate cerebral blood flow (CBF) and cerebral metabolism in patients that are at a risk of cerebral ischemia, measuring jugular venous oxygen saturation (SjvO2) allows clinicians to determine the relationship between them [1, 2]. Catheters containing optical fibers are used for continuous SjvO2 monitoring, and it was found that normal SjvO2 values range from 55 to 75 % [3–5]. Low SjvO2 levels are indicative of an increase in cerebral metabolism relative to CBF or of ischemia or hypoperfusion, which induces decreases in CBF relative to cerebral metabolism. In contrast, high SjvO2 levels indicate either a decrease in cerebral metabolism relative to CBF or hyperemia, which induces increases in CBF relative to cerebral metabolism. As SjvO2 is influenced by respiratory and circulatory dynamics, metabolic factors, the hemoglobin concentration, arterial carbon dioxide partial pressure, and arterial oxygen partial pressure, these factors must be considered when interpreting fluctuations in SjvO2 levels. In this chapter, the usefulness of SjvO2 monitoring, the significance of abnormal SjvO2 levels, and relevant countermeasures are reviewed.

Corneal depression immediately after cardiac surgery.

that this agent might partially account for the corneal depression. However, low perfusion pressure and mannitol administration during CPB are not rare in cardiac surgery. Many other factors have also been suggested to reduce intraoperative IOP and aqueous humor volume including hypocapnia, anesthetics, narcotics, and non-depolarizing muscle relaxants [1]. Therefore, it is difficult to identify the precise cause of the corneal depression seen in our patients. Further studies are needed to elucidate the causes of reductions in aqueous humor in cardiac surgery.