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ABSTRACT: We examined the effects of different anesthetics on cerebral oxygenation and systemic hemodynamics in patients undergoing surgery in beach chair position (BCP). Jugular venous bulb oxygen saturation (SjvO2) and regional cerebral tissue oxygen saturation (SctO2) were determined while patients were placed from the supine to BCP. Whether SctO2 and SjvO2 are interchangeable in assessing the cerebral oxygenation was also examined.
Forty patients undergoing shoulder surgery in BCP were randomly assigned to receive sevoflurane-nitrous oxide (S/N) or propofol-remifentanil (P/R) anesthesia. Four patients taking angiotensin II receptor antagonists were excluded post hoc. Mean arterial pressure and heart rate, as well as SjvO2 and SctO2, were measured before (postinduction baseline in supine position) and after BCP.
Mean arterial pressure decreased by BCP in both groups. It was, however, significantly higher in S/N (n = 19) than in P/R group (n = 17) at 7 to 8 min after the positioning. SjvO2 also significantly decreased after BCP in both groups, the magnitude of which was lower in S/N than in P/R group (11 ± 10% vs. 23 ± 9%, P = 0.0006). The incidences of SjvO2 <50% and mean arterial pressure less than 50 mmHg were lower in S/N group, but SctO2and the incidence of cerebral desaturation (more than 20% decrease from baseline) did not significantly differ between the groups. SctO2 and SjvO2 were only weakly correlated (β = 0.218, r2 = 0.133). Bland-Altman analysis showed a mean difference of -7.2% with 95% limit of agreement between -38.2% and 23.8%.
The margin of safety against impaired cerebral oxygenation is greater and SjvO2 is more preserved with S/N than with P/R anesthesia. SctO2 may not be reliable in detecting a low SjvO2 during the surgery in BCP.
Anesthesiology 03/2012; 116(5):1047-56. · 5.36 Impact Factor
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ABSTRACT: Opioid agonists have been implicated in neuroprotection from hypoxic injury through regulating mitogen-activated protein kinases and cytokines. We determined the effects of remifentanil in focal brain ischemia and reperfusion (I/R) injury. Mechanisms linked to mitogen-activated protein kinases, including extracellular signaling-regulated kinase (ERK) 1/2, p38 kinases, and c-Jun N-terminal kinase (JNK), and various cytokines were also examined.
Male Sprague-Dawley rats were subjected to an I/R insult consisting of 90 minutes' middle cerebral artery occlusion (MCAO) followed by reperfusion under general anesthesia. Neurological deficit scores and infarct volume were determined after 24 hours of reperfusion. Remifentanil (5 μg/kg/min) was given alone or combined with naltrindole (δ-opioid receptor antagonist; 1 mg/kg), D-Phe-Cys-Tyr-D-Trp-Orn-Thr-Pen-Thr-NH(2) (μ-opioid receptor antagonist; 1 mg/kg), or 5'-guanidinonaltrindole (κ-opioid receptor antagonist; 1 mg/kg). Opioid antagonists were administered 20 minutes before MCAO. Remifentanil infusion was started 10 minutes before MCAO and continued throughout. The control group was without drugs. The expression levels of ERK1/2, p38, and JNK, and also those of tumor necrosis factor-α (TNF-α) and interleukin-6, were determined after 1, 3, and 24 hours of reperfusion.
Remifentanil significantly improved the functional outcome and reduced the infarct volumes (69.0±24.3 mm(3) vs. 108.9±24.8 mm(3)), which were not affected by D-Phe-Cys-Tyr-D-Trp-Orn-Thr-Pen-Thr-NH(2) or 5'-guanidinonaltrindole, but were abolished by naltrindole. The I/R insult enhanced the phosphorylation of ERK 1/2 and the expression of TNF-α, which were significantly reduced by remifentanil. Neither the phosphorylation of p38 and JNK nor the production of interleukin-6 was altered throughout the experiment.
Remifentanil may be neuroprotective against focal I/R injury, possibly through the activation of δ-opioid receptors and attenuation of ERK 1/2 activity and TNF-α production, in the rat brain.
Journal of neurosurgical anesthesiology 01/2012; 24(1):51-7. · 2.41 Impact Factor
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ABSTRACT: Endotracheal intubation usually causes transient hypertension and tachycardia. The cardiovascular and arousal responses to endotracheal and endobronchial intubation were determined during rapid-sequence induction of anesthesia in normotensive and hypertensive elderly patients.
Patients requiring endotracheal intubation with (HT, n = 30) or without hypertension (NT, n = 30) and those requiring endobronchial intubation with (HB, n = 30) or without hypertension (NB, n = 30) were included in the study. Anesthesia was induced with intravenous thiopental 5 mg/kg followed by succinylcholine 1.5 mg/kg. After intubation, all subjects received 2% sevoflurane in 50% nitrous oxide and oxygen. Mean arterial pressure (MAP), heart rate (HR), plasma catecholamine concentration, and Bispectral Index (BIS) values, were measured before and after intubation.
The intubation significantly increased MAP, HR, BIS values and plasma catecholamine concentrations in all groups, the peak value of increases was comparable between endotracheal and endobronchial intubation. However, pressor response persisted longer in the HB group than in the HT group (5.1 ± 1.6 vs. 3.2 ± 0.9 min, P < 0.05). The magnitude of increases in MAP and norepinephrine from pre-intubation values was greater in the hypertensive than in the normotensive group (P < 0.05), while there were no differences in those of HR and BIS between the hypertensive and normotensive groups.
Cardiovascular response and arousal response, as measured by BIS, were similar in endobronchial and endotracheal intubation groups regardless of the presence or absence of hypertension except for prolonged pressor response in the HB group. However, the hypertensive patients showed enhanced cardiovascular responses than the normotensive patients.
Korean journal of anesthesiology 02/2011; 60(2):90-7.
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ABSTRACT: Inverted takotsubo cardiomyopathy (TTC), a variant of stress-induced cardiomyopathy, features transient myocardial dysfunction characterized by a hyperdynamic left ventricular apex and akinesia of the base. Herein, we describe a 38-year-old primigravida with severe preeclampsia who had active labour for 4 h followed by an emergency caesarean delivery. She developed postpartum haemorrhage due to uterine atony complicated by pulmonary oedema, which was managed with large-volume infusion and hysterectomy. Her haemodynamic instability was associated with cardiac biomarkers indicative of diffuse myocardial injury and echocardiographic findings of an "inverted" TTC. The patient was almost fully recovered one month later. Our case shows that a reversible inverted TTC may result from a prolonged painful labour. TTC should be listed in the differential diagnosis of the patient presenting with pulmonary oedema of unknown origin, especially in patients with severe preeclampsia.
Case reports in anesthesiology. 01/2011; 2011:164720.
