Masaji Nishimura

Low dose intrathecal morphine and pain relief following caesarean section.

Healthy women who underwent caesarean section under spinal anaesthesia were studied to determine the extent of postoperative analgesia and side-effects produced by low doses of intrathecal morphine. Patients were randomly allocated to receive, in double-blind fashion, 0 mg (group 1: control group), 0.05 mg (group 2), 0.1 mg (group 3), or 0.2 mg (group 4) of morphine, with 10 mg tetracaine in 10% dextrose 2.5 ml. (n = 20 x 4 groups). The effect of intrathecal morphine was examined in terms of the duration until the first supplemental analgesic was needed and the numbers of the doses within the first postoperative 48 h. Pain relief was significantly greater in groups 3 and 4 than in group 1. The incidence of nausea, vomiting and pruritus increased in a dose-dependent manner. No patient developed respiratory depression. Our results suggest that postoperative analgesia lasts more than 24 h with 0.1 mg or 0.2 mg of intrathecal morphine. Since the incidence of side-effects was higher at 0.2 mg, 0.1 mg may be the optimum dose for caesarean section.

Effect of a Polymorphonuclear Elastase Inhibitor (Sivelestat Sodium) on Acute Lung Injury After Cardiopulmonary Bypass: Findings of a Double-Blind Randomized Study

PurposeWe evaluated the effect of sivelestat sodium (SiV), a novel synthesized polymorphonuclear (PMN) elastase inhibitor, on acute lung injury (ALI) caused by cardiopulmonary bypass (CPB).MethodsFourteen patients who underwent cardiopulmonary surgery using CPB, followed by the development of both systemic inflammatory response syndrome (SIRS) and ALI, were treated with either 0.2 mg/kg per hour SiV (SiV group, n = 7) or saline (control group, n = 7) for 4 days from the time of arrival in the intensive care unit.ResultsThe SiV group had a significantly lower ratio of serum PMN elastase and interleukin (IL)-8, a significantly lower ratio of the respiratory index, and a significantly higher ratio of PaO2/FiO2 after 24 h of treatment than the control group.ConclusionSivelestat sodium suppressed the production of PMN elastase and IL-8, resulting in improved respiratory function in patients with ALI caused by CPB.

Tacrolimus-induced life-threatening arrhythmia in a pediatric liver-transplant patient

normal ranges. Tacrolimus is one of the most frequently used immunosuppressive agents, and arrhythmia is a little-recognized adverse effect. Tacrolimus is a macrolide compound that is considered to prolong QT intervals and result in torsades de pointes [3]. Johnson first reported prolonged QT intervals and torsades de pointes in a 10-yearold patient [1]. A second report concerned a 35-year-old woman with a long history of renal failure [2]. In both cases tacrolimus was infused intravenously. Intravenous administration more rapidly increases the drug concentration; however, in the present case tacrolimus was administered orally through a nasogastric tube. The presence of hepatic dysfunction appears to affect the metabolism of tacrolimus and prolong the half-life of the drug. In the case that we are reporting the data do not show a good correlation between QTc and tacrolimus concentration. The patient was a small infant, and the QT interval was difficult to evaluate because of the relatively higher heart rate of infants. In our infant patient a variety of arrhythmia, SVT, and VT developed. SVT has never before been reported as an adverse effect of tacrolimus. It is not clear whether this effect was due to the young age of this patient. SVT was successfully treated with procainamide and cibenzoline, the drugs also induce QT prolongation and ventricular arrhythmia. This influence might have induced VT even when tacrolimus concentration was within the therapeutic range. After liver transplantation, a 1-year-old infant developed a various arrhythmia. Because the arrhythmia associated with tacrolimus may be life-threatening, patients should be monitored carefully when any type of arrhythmia develops.

Functional Residual Capacity Measurement during Tracheal Gas Insufflation

Objective. Tracheal gas insufflation (TGI) is considered an adjunctive method to enhance carbon dioxide elimination during permissive hypercapnia in patients with acute respiratory distress syndrome. Due to increasing tidal volume and/or expiratory resistance, TGI may cause intrinsic PEEP (PEEPi), and may lessen the advantages of permissive hypercapnia. There is no reliable method to measure PEEPi during TGI. Using an argon washout method to evaluate dynamic hyperinflation, we developed a method to measure FRC with TGI flow. Methods. We measured FRC during TGI by washing out both the ventilator and TGI circuit with 100% oxygen (O2) previously equilibrated with 10% argon and 90% O2. To test the accuracy of our system, we measured the volume in a model lung composed of two flasks. The FRC of the model lung was changed by varying its volume of water, to active 500, 1000, and 1500 mL. The change of FRC (ΔFRC) of the model lung was measured at a flow of 0, 4, 8, and 12 L/min. Then the FRC of a bellows-type model lung was measured at the same TGI flow. PEEPi of the model lung was also recorded as the pressure inside the bellows at end-expiration. Results. Our FRC measurements were accurate within 10% except for that of 500 mL without TGI (12.7% ± 1.1%). As inspiratory time (TI) and/or TGI flow increased, the FRC of the bellows-type model lung increased. PEEPi and ΔFRC showed a positive correlation (r = 0.843, p < 0.001). The higher the TGI flow, the greater was the ΔFRC with both continuous and expiratory-phase TGI. FRC during continuous TGI was higher than during expiratory-phase TGI especially during long TI and high TGI flow. Conclusions. The system developed in this study can be used as a method to detect air-trapping during TGI.

Dynamic measurement of intrinsic PEEP does not represent the lowest intrinsic PEEP

Objective: Dynamic intrinsic PEEP (PEEPi-dyn) is the airway pressure required to overcome expiratory flow and is considered to represent the lowest regional PEEPi. However, there are few data to validate this assumption. We investigated if PEEPi-dyn represents the lowest PEEPi. Setting: The animal laboratory at the Osaka University Medical School. Measurements and results: We compared static PEEPi (PEEPi-stat) and PEEPi-dyn in healthy animals. Five adult white rabbits (2.77 ± 0.05 kg) were anesthetized, tracheostomized, and intubated with several different sizes of endotracheal tubes (ETT) (2.0, 2.5, 3.0, 3.5, or 4.0 mm i. d.). The animals were paralyzed and ventilated (Siemens Servo 900C). Baseline ventilator settings were at a rate of 50/min, inspiratory:expiratory (I:E) ratio of 2:1 or 4:1, and minute ventilation was manipulated to create 3 or 5 cm H2O PEEPi-stat. PEEPi-stat was measured using the expiratory hold button of the ventilator. PEEPi-dyn showed large variations. In all ventilator settings, PEEPi-dyn was higher than PEEPi-stat (p < 0.001). The larger the ETT, the higher the PEEPi-dyn at an I:E ratio of 2:1 (p < 0.05). The higher the minute ventilation, the greater the difference between PEEPi-stat and PEEPi-dyn. The tidal volume and the difference showed a significant correlation (r2 = 0.514, p < 0.001). Conclusions: The value of PEEPi-dyn was dependent on ventilatory settings, and PEEPi-dyn does not necessarily represent the lowest regional PEEPi within the lungs.