Ryokichi Goto

Effects of Exogenous Intravenous Glucose on Plasma Glucose and Lipid Homeostasis in Anesthetized Children

Whether or not intravenous glucose administration during pediatric anesthesia is necessary remains a controversial issue. The current study was designed to investigate the effect of glucose infusion on concentrations of plasma glucose, nonesterified fatty acids (NEFA), triglycerides, ketone bodies, and insulin and to determine whether the use of solutions containing less than 5% glucose would maintain physiologic plasma glucose concentrations during tympanoplasty lasting about 6 h. Forty-five children aged between 1.5 and 9 yr were divided randomly into three groups of 15 patients each to receive the following intravenous solutions: LR groups, lactated Ringers solution (LR) alone; D2LR group, 2% glucose in LR; and D5LR group, 5% glucose in LR. All fluids were infused at a rate of 6 ml.kg-1.h-1 until 1 h after anesthesia. In the LR group, the plasma glucose concentrations remained unchanged perioperatively compared with basal values, whereas in the D2LR group they showed a gradual increase during surgery but remained normoglycemic. On the other hand, in the D5LR group, the plasma glucose concentrations increased markedly both during and after the operation. Furthermore, 3 of 15 patients showed hyperglycemia of more than 300 mg.dl-1 during anesthesia. There was no evidence of lipid mobilization or impaired secretion of insulin, since plasma NEFA, triglycerides, ketone bodies, and insulin remained within normal concentration ranges throughout the sample period in the three groups.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of diltiazem on the cardiovascular response to tracheal intubation

The efficacy of diltiazem in the attenuation of the cardiovascular response to laryngoscopy and tracheal intubation was studied in patients who received 0.2 or 0.3 mg/kg diltiazem 60 seconds before the start of laryngoscopy. These data were compared with a control group who received saline. Each group consisted of 10 patients who had elective surgery. Patients who received saline showed a significant increase in mean arterial pressure and rate pressure product associated with tracheal intubation. These increases after tracheal intubation were reduced in diltiazem‐treated patients compared with those of the control group (p < 0.05). The data suggest that a bolus injection of diltiazem is a simple, practical and effective method to attenuate the hypertensive response to laryngoscopy and tracheal intubation.

Inhibitory Effect of Barbiturates and Local Anaesthetics on Protein Kinase C Activation

A calcium- and phospholipid-dependent protein kinase C subspecies purified from rat brain was inhibited by thiamylal, thiopentone, pentobarbitone, mepivacaine and bupivacaine. This was attributed to the inhibition of the activation process rather than to direct interaction with the active site of the enzyme. It is well established that unsaturated diacylglycerol markedly increases the affinity of protein kinase C for calcium ions. Kinetic analysis suggested that pentobarbitone brought about the inhibition by competing with the diacylglycerol diolein and that mepivacaine and bupivacaine competed with the phospholipid phosphatidylserine used in the assay. The possibility exists that the effects of local anaesthetics on the function of various tissues are due, in part, to an inhibitory action on protein kinase C.

Effects of prostaglandin E1 on the cardiovascular response to tracheal intubation

STUDY OBJECTIVE To evaluate the efficacy of prostaglandin E1 in attenuating the hypertensive response to laryngoscopy and intubation. DESIGN Controlled, comparative, and randomized study. SETTING Induction of anesthesia for elective surgery at a university hospital. PATIENTS Thirty normotensive patients (ASA physical status I) undergoing elective surgery divided into three groups. Each group consisted of ten patients. INTERVENTIONS Anesthesia was induced with thiopental sodium 5 mg/kg intravenously, and tracheal intubation was facilitated with vecuronium 0.2 mg/kg. Either 0.3 micrograms/kg of prostaglandin E1, 0.6 micrograms/kg of prostaglandin E1, or saline (control) was injected 15 seconds before starting direct laryngoscopy (within 30 seconds), which was attempted 2 minutes after administration of thiopental sodium and vecuronium. MEASUREMENTS AND MAIN RESULTS Patients receiving saline showed a significant increase in mean arterial pressure and rate-pressure product associated with tracheal intubation. These increases following tracheal intubation were significantly less in prostaglandin E1-treated patients than in the control group (p less than 0.05). CONCLUSIONS A single rapid intravenous administration of prostaglandin E1 is a practical pharmacologic and safe method to attenuate the hypertensive response to tracheal intubation. The use of 0.6 micrograms/kg of prostaglandin E1 as a supplement during induction is recommended for reducing the pressor response to intubation on the basis of rate-pressure product and mean arterial pressure following intubation as an index.

Attenuation of hypertensive response to tracheal intubation with nitroglycerin

STUDY OBJECTIVE To evaluate the efficacy and safety of intravenous (IV) nitroglycerin in attenuating the hypertensive response to laryngoscopy and intubation as a new application of the drug. DESIGN Controlled, randomized, double-blind study. SETTING University hospital. PATIENTS Thirty normotensive patients (ASA physical status I) undergoing elective surgery were divided into three groups of ten patients each. INTERVENTIONS Anesthesia was induced with thiopental sodium 5 mg/kg i.v., and tracheal intubation was facilitated with vecuronium 0.2 mg/kg i.v. During anesthesia, ventilation was assisted or controlled with 1% enflurane and 50% nitrous oxide in oxygen. Either 1.5 micrograms/kg of nitroglycerin, 2.5 micrograms/kg of nitroglycerin, or saline (control) was administered IV simultaneously with the start of laryngoscopy (lasting 30 seconds), which was attempted 2 minutes after administration of thiopental sodium and vecuronium. MEASUREMENTS AND MAIN RESULTS Patients receiving saline showed a significant increase in mean arterial pressure and rate-pressure product associated with tracheal intubation. These increases following tracheal intubation were significantly reduced in nitroglycerin-treated patients compared with those in the control group (p < 0.05). CONCLUSION A single, rapid IV dose of nitroglycerin is a simple, practical, effective, and safe method to attenuate the hypertensive response to laryngoscopy and tracheal intubation.

Perioperative effect of methylprednisolone given during lung surgery on plasma concentrations of C3a and C5a.

Methylprednisolone or saline (placebo) solution was infused intravenously in 28 patients undergoing elective lobectomy for lung cancer. The state of the complement system during and after surgery and the effects of methylprednisolone on biologically active products of complement were studied by measurements of plasma C3a and C5a anaphylatoxins and leukocyte counts in peripheral blood perioperatively. In the placebo group plasma concentrations of C3a were significantly increased on postoperative days 1 and 2, whereas C5a had risen significantly 6 hours after surgery and on days 1 and 2. Methylprednisolone infusion during surgery eliminated the postoperative elevation of C3a and C5a. The postoperative leukocyte count in peripheral blood was higher in the methylprednisolone group than in the controls. The observations indicated that methylprednisolone may reduce the influx of leukocytes from peripheral blood into the airways by attenuating production of biologically active complements.

Effects of Nilvadipine on the cardiovascular responses to tracheal intnhation

STUDY OBJECTIVE To evaluate the efficacy of nilvadipine given orally in attenuating the hypertensive response to laryngoscopy and intubation. DESIGN Controlled, randomized, double-blind study. SETTING Induction of anesthesia for elective surgery at a university hospital. PATIENTS Thirty normotensive patients (ASA physical status I) undergoing elective surgery were divided into three groups of ten patients each. INTERVENTIONS Either 2 mg of nilvadipine, 4 mg of nilvadipine, or a placebo (control) was administered orally 90 minutes before induction of anesthesia. Anesthesia was induced with thiopental sodium 5 mg/kg intravenously, and tracheal intubation was facilitated with vecuronium 0.2 mg/kg. During anesthesia, ventilation was assisted or controlled with 1% enflurane and 50% nitrous oxide (N2O) in oxygen. Laryngoscopy lasting 30 seconds was attempted 2 minutes after administration of thiopental sodium and vecuronium. MEASUREMENTS AND MAIN RESULTS Patients receiving the placebo showed a significant increase in mean arterial pressure (MAP) and heart rate associated with tracheal intubation. The increase in MAP following tracheal intubation was significantly lower in nilvadipine-treated patients than in the control group (p less than 0.05). However, neither dose of nilvadipine attenuated the tachycardic response to intubation. CONCLUSIONS Oral administration of nilvadipine before induction of anesthesia is a simple and practical method for attenuating pressor response to laryngoscopy and tracheal intubation after standard elective induction under additional 1% enflurane-N2O anesthesia.

Partial attenuation of the cardiovascular responses to tracheal intubation with oral nisoldipine.

STUDY OBJECTIVE To evaluate the efficacy and safety of nisoldipine given orally in attenuating the cardiovascular responses to laryngoscopy and tracheal intubation. DESIGN Randomized, double-blind, placebo-controlled study. SETTING Induction of anesthesia for elective surgery at a university hospital. PATIENTS Thirty normotensive patients (ASA physical status I) undergoing elective surgery were assigned to one of three groups; placebo, nisoldipine 5 mg, or nisoldipine 10 mg. Each group consisted of ten patients. INTERVENTIONS Either 5 mg of nisoldipine, 10 mg of nisoldipine, or a placebo was administered orally 2 hours before induction of anesthesia. Anesthesia was induced with thiopental sodium 5 mg/kg intravenously, and tracheal intubation was facilitated with vecuronium 0.2 mg/kg. During anesthesia, ventilation was assisted or controlled with 1% enflurane and 50% nitrous oxide in oxygen. Laryngoscopy lasting 30 seconds was attempted 2 minutes after administration of thiopental sodium and vecuronium. MEASUREMENTS AND MAIN RESULTS Patients receiving the placebo showed a significant increase in mean arterial pressure associated with tracheal intubation. These increases following tracheal intubation were significantly reduced in patients receiving nisoldipine 10 mg compared with patients receiving the placebo (p less than 0.05). CONCLUSIONS Oral administration of nisoldipine before induction of anesthesia is a simple, practical, and safe method for attenuating pressor response to laryngoscopy and tracheal intubation.

Prostaglandin E1 and tracheal intubation : relationship between the cardiovascular responses and plasma catecholamine concentrations

A study was carried out on 30 normotensive patients (American Society of Anesthesiologists physical status 1) to investigate whether or not a suppressive effect of 0.3 or 0.6 μg/kg prostaglandin E1 on the hypertensive response to tracheal intubation was due to inhibition of the increase in plasma catecholamine concentrations following the stressful stimulation. A total of 30 patients in three groups underwent elective surgery. Anaesthesia was induced with 5 mg/kg sodium thiopentone given intravenously and tracheal intubation was facilitated by 0.2 mg/kg vecuronium. Either saline (group A) or 0.3 (group B) or 0.6 μg/kg (group C) prostaglandin E1 was administered intravenously 15 s before direct laryngoscopy (lasting 30 s) which was attempted 2 min after administering thiopentone and vecuronium. All groups exhibited significant (P < 0.05) increases in mean arterial pressure, heart rate, rate – pressure product and plasma noradrenaline concentrations following tracheal intubation, but the increases in mean arterial blood pressure and rate – pressure product were significantly (P < 0.05) less in groups B and C than in group A. Prostaglandin E1, however, enhanced the increase in plasma noradrenaline concentrations following intubation. Data suggest that attenuation of the pressor response to intubation by prostaglandin E1, may not be due to inhibition of the noradrenaline release stimulated by intubation but to inhibition of noradrenaline-induced vasoconstriction.

Attenuation of the cardiovascular and catecholamine responses to tracheal intubation with oral guanabenz.

We conducted a randomized, placebo-controlled, and double- blind study to evaluate the efficacy of oral guanabenz, an α2−adrenergic agonist, in attenuating the cardiovascular and catecholamine responses to laryngoscopy and tracheal intubation in 30 normotensive (ASA physical status 1) patients undergoing elective surgery. They were allocated to one of three groups (n = 10 for each): placebo, 4 mg, or 6 mg of guanabenz groups. These tablets were administered 2 h before the induction of anesthesia. Anesthesia was induced with thiopental 15.0 mg/kg intravenously (IV), and tracheal intubation was facilitated by the administration of vecuronium, 0.2 mg/kg IV. During anesthesia, ventilation was assisted or controlled with 1% enflurane and 50% nitrous oxide in oxygen. Laryngoscopy lasting 30 s was attempted 2 min after the administration of thiopental and vecuronium. Patients receiving placebo showed a significant increase in mean arterial blood pressure, heart rate, and plasma catecholamine concentrations in response to tracheal intubation. These changes were significantly smaller in patients receiving either dose of guanabenz (P < 0.05). Oral administration of guanabenz before induction of anesthesia is a simple and effective method for attenuating the pressor and tachycardic responses to laryngoscopy and tracheal intubation with the drug acting at least partly via inhibition of the increases in plasma catecholamines concentrations.