Yukiko Goda

Regional differences in skin blood flow and temperature during total spinal anaesthesia

Three patients were studied to determine the changes in regional skin temperature and blood flow during extensive sympathetic blockade following total spinal anaesthesia (TSA). Skin temperature was measured at the right upper arm, the right anterior chest at the nipple level, the right hand and the foot, using infrared thermography. Skin blood flow of the right upper arm (C6 area) was measured with a laser Doppler flowmeter. The temperature of the truncal area, arm and leg decreased by 1°C following TSA, whereas the temperature of the hand and foot increased by 3°C. The mean blood flow in three patients decreased to 26.1, 61.4, 51.7% of the control values 15 min after TSA. Our results indicate that extensive sympathetic nervous blockade during total spinal anaesthesia induces regional different changes in skin temperature and decrease in truncal skin blood flow.RésuméTrois patients ont été étudiés afin de déterminer les changements régionaux de la température cutanée et du débit sanguin, lors d’un bloc sympathique étendu, suite à une anesthésie sousarachnoïdienne totale (TSA). La température a été mesurée à différentes sites, à l’aide de la thermographie à infrarouge: le bras droit supérieur, la surface antérieure droite du thorax au niveau du mamelon, ainsi que la main et le pied droits. Le débit sanguin cutané du bras droit supérieur (dermatome C6) a été mesuré à l’aide d’un débitmètre au lazer et utilisant le Doppler. La température de la surface thoracique, du bras et de la jambe a diminué de 1°C suite à la TSA, alors que la température de la main et du pied a augmenté de 3° C. Le débit sanguin moyen chez les trois patientys a diminué de 26,1, 61,4 et 51,7% des valeurs de contrôle quinze minutes après la TSA. Nos résultats indiquent qu’un bloc nerveux sympathique étendu lors d’une anesthésie sousarachnoïdienne totale provoque des changements régionaux différents au niveau de la température cutanée et dimine le débit sanguin cutané thoracique.

Subanalgesic ketamine enhances morphine-induced antinociceptive activity without cortical dysfunction in rats.

PurposeKetamine, a noncompetitive N-methyl-d-aspartate receptor antagonist, has been used for the treatment of cancer pain as an analgesic adjuvant to opioids. However, ketamine is known to produce psychotomimetic side effects including cognitive impairments under a high-dose situation, presumably as the result of cortical dysfunction. Here, we investigated whether low-dose ketamine was useful as an analgesic adjuvant to morphine for pain control, focusing on frontocortical function.MethodsTo assess the analgesic effects of ketamine with or without morphine, we performed behavioral and histochemical experiments, using the hot plate test and c-Fos expression analysis in rats. The effect on cortical function was also determined by prepulse inhibition (PPI) of the acoustic startle and evoked potentials in the hippocampal CA1-medial prefrontal cortex (mPFC) synapses as measures of synaptic efficacy.ResultsCoadministration of ketamine as a subanalgesic dose significantly enhanced intraperitoneal morphine-induced antinociceptive response, which was measured as the increased reaction latency in the hot plate test. In addition, the noxious thermal stimulus-induced c-Fos expression in the ventrolateral periaqueductal gray matter was significantly suppressed by concomitant ketamine and morphine. In contrast, the subanalgesic dose of ketamine did not impair PPI and synaptic efficacy in the mPFC.ConclusionThe present results indicate that the morphine-induced analgesic effect is enhanced by a concomitant subanalgesic dose of ketamine without affecting cortical function. Our findings possibly support the clinical notion that low-dose ketamine as an analgesic adjuvant has therapeutic potential to reduce opioid dosage, thereby improving the quality of life in cancer pain patients.

Secondary hyperparathyroidism shortens the action of vecuronium in patients with chronic renal failure

The authors studied the duration of action of vecuronium in 15 patients with normal renal function and 40 patients with chronic renal failure to evaluate the effect of secondary hyper-parathyroidism on the action of vecuronium. The patients were divided into four groups: 15 patients with normal renal function (Group A); nine patients with chronic renal failure who did not need haemodialysis (Group B); 15 anephric patients who did not require parathyroidectomy (Group C); and 16 anephrenic patients who underwent parathyroidectomy because of severe secondary hyperparathyroidism (Group D). The ratio of the height of the first twitch (T1) to the baseline value before vecuronium administration was measured by an electromyogram. Baseline T1 was obtained after anaesthesia induction with thiamylal iv. The time to 10% recovery of the first twitch (REC 10) after administration of vecuronium 0.12 mg · Kg−1 iv was measured in each group. Anaesthesia was maintained with isoflurane and nitrous oxide in oxygen, and supplemented with fentanyl iv. Patients in Group D showed shorter REC 10 (51 ± 4 min) than those in Groups B (71 ± 6 min) and C (80 ± 10 min) (P < 0.05), but similar REC 10 to patients in Group A (37 ±4 min). These results suggest that the duration of action of vecuronium in anephric patients with secondary hyperparathyroidism is shorter than in those without secondary hyperparathyroidism.RésuméLes auteurs étudient la durée d’action du vécuronium auprès de 15 patients avec une fonction rénale normale et de 40 patients avec une insuffisance rénale chronique afin d’évaluer l’effet d’une hyperparathyroïdïe secondaire sur l’action du vécuronium. Les patients sont répartis en quatre groupes: quinze patients avec une fonction rénale normale (Groupe A); neuf patients avec une insuffisance rénale chronique non hémodialysés (Groupe B); 15 patients anéphriques qui n’ont pas besoin d’une parathyroïdectomie (Groupe C) et 16 patients anéphriques qui subissent une parathyroïdectomie à cause d’une hyperparathyroïdie secondaire grave (Groupe D). Le rapport de la hauteur de la première contraction (T1) à la contraction de base avant l’administration de vécuronium est mesurée par un électromyogramme. Le T1 de base est obtenu après l’induction de l’anesthésie avec du thiamylal iv. Le temps de récupération à 10% dès la première contraction (REC 10) après l’administration iv de 0,12 mg · Kg−1 de vécuronium est mesuré dans chaque groupe. L’anesthésie est maintenue avec de l’isoflurane et du protoxyde d’azote dans l’oxygène et des suppléments de fentanyl iv. Les patients du groupe D montrent un plus court REC 10 (51 ± 4 min) que ceux du groupe B (71 ± 6 min), et du groupe C (80 ± 10 min) (P < 0,05), mais un REC 10 semblable aux patients du groupe A (37 ± 4 min). Les résultats suggèrent que la durée d’action du vécuronium chez les patients anéphriques est plus courte avec que sans hyperparathyroïdie secondaire.

Hyperparathyroidism in Patients with Chronic Renal Failure Shortens the Action of Vecuronium

The duration of vecuronium in anephric patients is known to have interpatient variability. It was reported that primary hyperparathyroidism attenuated the action of atracurium. The interpatient variability may be in part due to the degree of parathyroid function. We evaluated the effect of secondary hyperparathyroidism on the duration of vecuronium in patients with chronic renal failure.

Does cyclosporine affect the duration of action of vecuronium in renal transplant recipients

The duration of action of vecuronium was tested in 41 surgical patients to evaluate whether cyclosporine modulates the action of vecuronium. The patients were divided into three groups: 12 patients with normal renal function (group A); 14 renal transplant recipients who had received cyclosporine before surgery (group B); and 15 patients with chronic renal failure undergoing surgery other than renal transplantation and who did not receive cyclosporine (group C). The times to 10% and 20% recovery of the first twitch (REC 10 and REC 20) after intravenous administration of vecuronium 0.12 mg·kg−1 were measured using an electromyogram in each group. REC 10 and REC 20 were significantly prolonged in the patients of group B (REC 10: 93±18 min, REC 20: 110±14 min) and group C (REC 10: 80±10 min, REC 20: 89±12 min) than in the patients of group A (REC 10: 39±5 min, REC 20: 45±5 min) (P<0.01). There was no significant difference in the duration of action of vecuronium between the patients of groups B and C. In summary, cyclosporine did not prolong the duration of action of vecuronium in the renal transplant recipients when the same dose was administered compared with the patients with chronic renal failure who did not receive cyclosporine.

Clinical Evaluation of Continuous Venous Oxygen Saturation Monitoring During Anesthesia

Clinical evaluation of continuous SvO2 monitoring during anesthesia was made in 14 surgical patients utilizing a fiberoptic reflectometry system combined with a pulmonary artery flow-directed balloon catheter. On-line values for SvO2 by the system were closely related to those obtained in vitro from a Radiometer ABL-300. There was a good correlation between changes of in vivo SvO2 and corresponding changes in cardiac index. We also observed that there was a significant correlation between SvO2 and oxygen extraction ratio. Our data indicate that continuous SvO2 monitoring during anesthesia can provide on-line information not only about hemodynamic state but also on oxygen transport.