Shuh Matsukawa

Elevated plasma levels of interleukin-6, interleukin-8, and granulocyte colony-stimulating factor during and after major abdominal surgery

STUDY OBJECTIVE To evaluate the influence of major abdominal surgery on the plasma levels of inflammatory cytokines interleukin-6 (IL-6), interleukin-8 (IL-8) and granulocyte colony-stimulating factor (G-CSF). DESIGN Prospective study. SETTING University hospital. PATIENTS 10 ASA physical status I and II patients undergoing upper abdominal surgery. INTERVENTIONS All patients received combined general-epidural anesthesia with isoflurane and nitrous oxide, after insertion of an epidural catheter at T7-T9 dosed with 1.5% lidocaine. MEASUREMENTS AND MAIN RESULTS Plasma cytokine (IL-6, IL-8, G-CSF) levels were determined with an enzyme-linked immunosorbent assay (ELISA) at pre-anesthesia, 0, 2, and 4 hours during surgery, and at the end of surgery, followed by sampling on the morning of postoperative days 1 (POD1) and 3 (POD3). Plasma cortisol levels were also determined. The plasma levels of IL-6 increased gradually after skin incision and reached the maximal value at the end of surgery (p < 0.001). IL-8 levels also increased from the baseline value to their maximum at the end of surgery (p < 0.05). G-CSF levels were elevated from the pre-anesthesia value to their maximum by the end of operation (p < 0.005). Plasma cortisol levels were increased after skin incision (p < 0.001). Postoperative cytokine levels correlated significantly with each other (r = 0.68, p < 0.05 for IL-6 vs. IL-8; r = 0.81, p < 0.005 for IL-6 vs. G-CSF; and r = 0.84, p < 0.005 for IL-8 vs. G-CSF). Postoperative IL-6 levels and intraoperative blood loss correlated significantly (r = 0.64, p < 0.05). CONCLUSIONS These results suggest that major upper abdominal surgery stimulates the release of inflammatory cytokines presumably from the operation site. Further study is warranted to evaluate the modulation of inflammatory responses in the perioperative period.

Hyperbaric oxygen therapy given 30 minutes after spinal cord ischemia attenuates selective motor neuron death in rabbits.

ObjectiveSpinal cord ischemia sometimes causes paraplegia because the spinal motor neuron cells are vulnerable to ischemia. Although various protective remedies for spinal cord injury have been reported, there have been few established clinical methods. Although hyperbaric oxygen (HBO) has been used clinically as a treatment for ischemia, the reason for its effectiveness is still uncertain because sufficient experimental data are lacking. DesignProspective, randomized, controlled study. SettingExperimental animal research laboratory in a university research center. SubjectsTwenty-three Japanese white rabbits, weighing 2–3 kg. InterventionsA modified rabbit spinal cord ischemia model of infrarenal aortic occlusion for 15 mins was employed. Rabbits were randomly assigned to four groups; the rabbits in group A did not undergo ischemic insults (n = 5). The rabbits in groups B and C underwent ischemic insult for 15 mins, followed by 1 hr of HBO treatment at 3 atm absolute with 100% oxygen at 30 mins (n = 6) or 6 hrs (n = 7) after reperfusion, respectively. The rabbits in group D underwent ischemic insult for 15 mins without HBO treatment (n = 5). Measurements and Main Results We observed neurologic functions for 14 days. The sections of the spinal cords were stained with hematoxylin and eosin, and the number of spinal motor neurons in ventral region was counted by light microscopy. All rabbits in groups A and B could stand, whereas all rabbits in groups C and D showed irreversible paraplegia on days 2 and 14 after reperfusion. Spinal motor neurons in ventral gray matter in groups C and D decreased significantly compared with those in groups A and B. ConclusionsHBO therapy shortly after ischemic insult had protective effects against ischemic spinal cord damage. However, delayed treatment with HBO did not change the prognosis.

A Weak Negative Inotropic Effect of Protamine Sulfate upon the Isolated Canine Heart Muscle

The direct effect of protamine sulfate upon myocardial inotropism was studied using an isolated canine heart muscle preparation. Isometric force (F) was decreased to 87.6 ± 1.2% of control values by a concentration of 50 × 10−3 g/L protamine, which is approximately equal to the estimated serum concentration of protamine when administered clinically in doses of 4 mg/kg. The decrease in F was accompanied by a decrease in the maximum velocity of force development (dF/dt) but no alteration in time to peak force. Administration of the preservative of protamine sulfate did not alter F and dF/dt. This suggests that protamine produces a direct negative inotropic effect, mediated by a decrease in intensity but not by a decrease in duration of the active state.

Effect of surfactant on respiratory failure associated with thoracic aneurysm surgery.

OBJECTIVE To study the effects of surfactant administration on the left lung after surgical repair of descending aortic aneurysms on postoperative respiratory failure. DESIGN Randomized, prospective, controlled study. SETTING Clinical investigation. PATIENTS Eleven patients with respiratory failure associated with thoracic aneurysm surgery. INTERVENTION Eleven adult patients with acute respiratory failure (PaO2/FIO2 <300 torr [<40 kPa]) after surgical repair of descending aortic aneurysms. The artificial surfactant (30 mg/kg) was given to the operated side of the lung by intrabronchial instillation in six patients (surfactant group), whereas nothing was instilled in the other five patients (control group). MEASUREMENTS AND MAIN RESULTS Hemodynamic parameters, blood gas, and peak inspiratory pressure were measured at the end of surgery, before surfactant instillation, and at 2, 6, 12, 24, and 48 hrs after surfactant instillation. At the end of surgery, the mean +/- SEM values of the PaO2/FIO2 ratio were 204 +/- 25 torr (27.2 +/- 3.3 kPa) in the surfactant group and 240 +/- 26 torr (32.0 +/- 3.5 kPa) in the control group. After 2, 6, 12, and 48 hrs, improvements in the PaO2/FIO2 ratios were observed in the surfactant group, whereas the control group showed no improvement. Two hours after surfactant instillation, the mean value in the PaO2/FIO2 ratio was significantly higher in the surfactant group (318 +/- 24 torr [42.4 +/- 3.2 kPa]) (p < .05) compared with the control group values (240 +/- 34 torr [32 +/- 4.5 kPa]). CONCLUSION Surfactant administration immediately after surgery restored gas exchange in postoperative respiratory failure associated with thoracic aneurysm surgery.

Effect of tube guide assembly of closed suction system on airway pressure gradient

We connected a Dual Adult TTL model 1600 test lung (Michigan Instruments, Grand Rapids, MI, USA), a pressure and flow sensor (OMR; Nihon Kohden, Tokyo, Japan), a TT (Mallinckrodt, St. Louis, MO, USA), another sensor, and an Evita 4 ventilator (Drägerwerk, Lubeck, Germany) in series (Fig. 2). Two kinds of TT (with IDs of 6.5 and 8.5mm) were used for this experiment. The distal side of each TT was set inside a plastic tube, which was connected to the test lung. The cuff was inflated with air to prevent leakage, and the proximal side of each TT was connected to the respiratory circuit of the Evita 4. We used the original Ballard Trach Care Directional Tip Closed Suction System for 12-Fr catheter (Ballard Medical Products, Midvale, UT, USA), and a modified closed suction system, in which the tube guide assembly in the L-connector was removed (Fig. 1). The settings of the Evita 4 ventilator were: tidal volume, 600ml; respiratory frequency, 12 breaths·min 1, inspiratory time, 1 s (with attenuation wave); FIO2, 0.21, inspiratory pause, 0%, and positive end-expiratory pressure (PEEP), 0cmH2O. The resistance and compliance of the test lung were set at 20cmH2O·l 1·s 1 and 0.05 l·cmH2O 1, respectively. The airway pressures were measured simultaneously at the proximal side of the closed suction system (P2) and the distal site of the TT (P1), and the flow was measured at the proximal site. Three signals (two pressures and one flow) were recorded simultaneously with a Power Book G3 (Apple Computer, Cupertino, CA, USA) via a MacLab AD converter (AD Instruments) at a sample rate of 100Hz. We calculated and analyzed the relationship between the airway pressure and the flow using Chart v3.6.4B5/s (AD Instruments) and Microsoft Excel (Microsoft, Redmond, WA, USA) for every breath. It has been reported that the pressure gradient across the TT (PTT) has a nonlinear dependence on the flow generated by the ventilator [2]. This relationship is

Neuromuscular blocking potency of fazadinium in man

The study was designed to compare the recovery rates of fazadinium and four other commonly used competitive muscle relaxants in forty patients and eight volunteers. One-fifth to 1/10 of the clinical doses of the muscle relaxants were diluted in 20 ml of saline and injected intravenously at the wrist after inflation of a pneumatic tourniquet on the upper arm. After 3 min the tourniquet was released and the recovery time of twitch tension from 25 to 75% of the control determined. Evoked force of middle finger adduction was measured at a frequency of 0.2 Hz. The mean 25-75% recovery times of twitch tension for tubocurarine, pancuronium, alcuronium, gallamine and fazadinium were 14.20 +/- 1.42, 12.30 +/- 1.02, 10.12 +/- 0.77, 10.07 +/- 1.12 and 9.90 +/- 0.87 min, respectively. The authors conclude that the dissociation rate of fazadinum from the receptor of the motor endplate appears to be the fastest among the competitive muscle relaxants studied in man.