Changes in body temperature during profound hypothermic cardiopulmonary bypass in adult patients undergoing aortic arch reconstruction

Purpose Our aim was to characterize changes in body temperatures during profound hypothermic cardiopulmonary bypass (CPB) conducted with the sternum opened.Methods In ten adult patients who underwent profound hypothermic (20°C) CPB for aortic arch reconstruction, pulmonary arterial temperature (PAT), nasopharyngeal temperature (NPT), forehead deep-tissue temperature (FHT), and urinary bladder temperature (UBT) were recorded every 1min throughout the surgery. In addition, the CPB venous line temperature (CPBT), a reasonable indicator of mixed venous blood temperature during CPB and believed to best reflect core temperature during stabilized hypothermia on CPB, was recorded during the period of total CPB.Results PAT began to change immediately after the start of cooling or rewarming, closely matching the CPBT (r = 0.98). During either situation, the other four temperatures lagged behind PAT (P 0.05); however, NPT followed PAT more closely than the other three temperatures (P 0.05). During stabilized hypothermia, PAT, NPT, and FHT, but not UBT, closely matched the CPBT, with gradients of less than 0.5°C.Conclusion During induction of profound hypothermia and its reversal on total CPB with the heart in situ, a PA catheter thermistor, presumably because of its placement immediately behind the superior vena cava, would provide a reliable measure of the mixed venous blood temperature. During stabilized profound hypothermia, PAT, NPT, and FHT, but not UBT, serve as a reliable index of core temperature.This work was presented, in part, at the 50th annual meeting of the Japanese Society of Anesthesiologists, Yokohama, May 29–31, 2003, and at the annual meeting of the American Society of Anesthesiologists, San Francisco, USA, October 11–15, 2003.     

Oxygen delivery and consumption in the perioperative period of coronary artery bypass grafting without blood transfusion

The perioperative changes in relationship between oxygen delivery (D¨_{O 2}) and oxygen consumption (V¨_{O 2}) were examined in forty patients who underwent coronary artery bypass grafting (CABG) without blood transfusion. Hemodilution was performed to maintain hematocrit of 19.2 ± 1.8% during cardiopulmonary bypass (CPB). Hemodynamic and metabolic parameters were measured in four stages; before CPB (stage I), after CPB (stage II), after ICU arrival (stage III), and the following day (stage IV). In each stage, there was a strong positive correlation between V¨_{O 2} and D¨_{O 2}. In stage I, a decrease in D¨_{O 2} was met with low V¨_{O 2}, and there was no imbalance between them (r = 0.67, P 0.01). V¨_{O 2} increased significantly in stage II, and this increased V¨_{O 2} was compensated by an increase in D¨_{O 2} sufficiently to meet tissue oxygen demand (r = 0.59, P 0.01). In stage III and IV, the increases in tissue oxygen requirements were met by increases in oxygen extraction ratio (r = 0.81, P 0.01, r = 0.60, P 0.01, respectively) reflected in lowered mixed venous oxygen tension and saturation. From these results, it is assumed that the adequate relationship between V¨_{O 2} and D¨_{O 2} can be maintained in the perioperative period of CABG without blood transfusion.(Mizushima A, Niimi Y: Oxygen Delivery and consumption in the perioperative period of coronary artery bypass grafting without blood Transfusion. J Anesth 4: 313–318, 1990)     

Hemodynamic and oxygen delivery-consumption changes during partial liver resection

The effects of partial liver resection on hemodynamics and the oxygen delivery-consumption relationship were evaluated in ten patients with hepatocellular carcinoma. The cardiac index and oxygen delivery were increased significantly (P 0.05) at 30 minutes after incision, 30min after liver resection and in the recovery room. Oxygen delivery decreased significantly (P 0.05) during liver resection. Oxygen consumption remained low throughout the procedure. We did not discover any flow-dependent change in oxygen consumption. Although our patients persisted a hyperdynamic state throughout surgery, their arterial ketone body ratio remained low. Therefore, it may be necessary to maintain a hyperdynamic state during partial liver resection in order to increase hepatic blood flow.(Iwasaka H, Kitano T, Mizutani A, et al.: Hemodynamic and oxygen delivery-consumption changes during partial liver resection. J Anesth 7: 145–150, 1993)     

Sustained effects of plasma norepinephrine levels on femoral-radial pressure gradient after cardiopulmonary bypass

In order to determine the influence of the sympathetic nervous system upon the femoral-radial artery pressure gradient after cardiopulmonary bypass (CPB), we examined plasma norepinephrine levels in 34 adult male patients undergoing coronary artery bypass grafting. Cardiovascular parameters, including systolic arterial pressure, mean arterial pressure, cardiac index (CI), systemic vascular resistance index (SVRI), pulmonary artery pressure (PAP), hemoglobin (Hb) and peak dP/dt of radial and femoral artery pressures were measured after sternotomy, and immediately after the discontinuation of CPB and 90min after CPB. Plasma norepinephrine levels were measured after sternotomy, after aortic declamping and 90min after CPB.The patients were divided into two groups. Group A consisted of 17 patients whose femoral minus radial systolic pressure difference was 15mmHg or more at 90min after CPB, while Group B consisted of 17 patients with the difference less than 15mmHg. Group A patients had significantly longer time values in the duration of both CPB (Group A 175 ± 10min; Group B 115 ± 12min, P 0.001) and aortic cross clamping (Group A 116 ± 7min, Group B 71 ± 9min, P 0.001).Although there was no significant difference in Hb or PAP of 90min after CPB in Groups A and B, the following values, listed in the order of A to B, were obtained; CI, 2.79 ± 0.10 versus 3.46 ± 0.16l·min^–1·m^–2 (P 0.01); mean radial artery pressure (MRP), 58.7 ± 2.4 versus 65.1 ± 1.8mmHg (P 0.05); peak dP/dt of radial artery pressure, 568 ± 64 versus 1026 ± 61mmHg·sec^–1 (P 0.001); and plasma norepinephrine concentration, 1.81 ± 0.25 versus 0.98 ± 0.10ng·ml^–1 (P 0.01), which were statistically significant.The higher femoral-radial artery pressure gradient after CPB was observed in patients with both a longer CPB time and a higher plasma norepinephrine concentration. These results suggest that a marked constriction of peripheral arteries might have produced a damped transmission of the pressure pulse to the radial artery.(Nakayama R, Goto T, Kukita I, et al.: Sustained effects of plasma norepinephrine levels on femoral-radial pressure gradient after cardiopulmonary bypass. J Anesth 7: 8–15, 1993)     

Effect of Nifedipine on the Healing of Left Colonic Anastomoses in Rats

Purpose Ca²⁺ channel blockers inhibit collagenase production and have a vasodilatatory effect. They also restrict the formation of ischemia-reperfusion induced free oxygen radicals. The aim of this study was to assess the effect of nifedipine on the healing of colonic anastomoses in a rat model.Methods Sixty Wistar rats weighing 240–290g were divided into four groups of 15 rats each: a 3rd day control group (group A), a 3rd day treatment group (group B), a 7th day control group (group C), and a 7th day treatment group (group D). The treatment groups were given Nifedipine 3mg/kg per day orally as three divided doses.Results The bursting pressure values of the anastomoses in the treatment groups were significantly higher than those in the control groups (P 0.05). The hydroxyproline content was also significantly higher in the treatment groups than in the control groups (P 0.05). Histologic examination confirmed that nifedipine treatment significantly increased collagen deposition and fibroblast ingrowth compared with controls (P 0.05).Conclusions These results clearly showed that nifedipine enhanced the stability of colonic anastomoses during the first postoperative week.     

浅低温体外循环冠脉搭桥患者术中氧供和氧耗变化

观察浅低温体外循环冠脉搭手术期间患者氧供和氧耗的变化特点。方法：冠脉搭桥术患者３０例,小剂量芬太尼辅以异氟醚和异丙酚维持麻醉,于麻醉后切皮瓣、开胸后体外循环前,体外循环３０分钟、６０分钟停机后２０仲,手术结束六个时点,观测氧供（ＤＯ２）、氧耗（ＶＯ２）氧摄取率（Ｏ２ＥＲ）、混合静脉血氧饱和度（ＳｖＯ２）、动脉血乳酸（ＢＬ）及血流动力学等变化。结果：和体外循环前相比,体外循环中和体外循环后除ＳｐＯ２     

Jugular Venous Oxygen Saturation During Mild Hypothermic Versus Normothermic Cardiopulmonary Bypass in Elderly Patients

Purpose. Age is known to be a major risk factor for adverse postoperative cognitive dysfunction after cardiac surgery. We conducted this study to determine if jugular venous oxygen saturation (SjvO₂) differed during mild hypothermic (32°C) and normothermic cardiopulmonary bypass (CPB) in elderly patients.Methods. Sixty patients aged over 70 years who underwent elective coronary artery bypass grafting were randomly divided into two groups. Group 1 (n = 30) underwent normothermic CPB (>35°C) and group 2 (n = 30) underwent mild hypothermic CPB (32°C). For the continuous monitoring of SjvO₂, a fiberoptic oximetry oxygen saturation catheter was inserted into the right jugular bulb after the induction of anesthesia. Hemodynamic parameters, and arterial and jugular venous blood gases were measured at seven time points.Results. The SjvO₂ in the normothermic group was lower at the onset of CPB and 20min after the onset, than from the time of induction of anesthesia until the start of surgery (period 1), the respective SjvO₂ values being 50.3% ± 1.0%, 50.1% ± 1.6%, and 59.5% ± 1.9% (P < 0.05). However, in the mild hypothermic group there were no changes in the SjvO₂ value throughout the study. The cerebral desaturation time (when the SjvO₂ value was <50%) and the ratio of the cerebral desaturation time to the total CPB time in the normothermic group differed significantly from those in the hypothermic group, being 19 ± 11min and 17% ± 10%, and 9 ± 3min and 8% ± 4%, respectively (P < 0.05).Conclusions. The SjvO₂ value was better during mild hypothermic CPB than during normothermic CPB in elderly patients.     

Airway occlusion pressure (P0.1) — A useful predictor for the weaning outcome in patients with acute respiratory failure —

Twenty-five patients who required mechanical ventilatory support (MVS) after major surgery or severe burns were studied to determine whether airway occlusion pressure (P_0.1) is a clinically useful indicator to predict the success or failure of the weaning trial. A total of 33 weaning trials were attempted on these patients. Of the 33 trials, 24 were followed by successful weaning and 9 by failure. Although the success group, when compared with the failure group, had a lower respiratory rate (P 0.001), a lower minute ventilation (P 0.001), a higher maximal voluntary ventilation to minute ventilation ratio (P 0.01) and a higher forced vital capacity (P 0.05), no threshold values separated the success from the failure group. The alveolar-arterial P_{O 2} gradient, with an Fi _{O 2} of 1.0, in weaning success and failure showed no statistical difference. In contrast, all patients in the success group had a P_0.1 of less than 3.5cmH₂O and those in the failure group had a P_0.1 of greater than 3.5cmH₂O (P 0.001). We conclude that P_0.1 is a clinically superior indicator for discontinuing MVS in patients with acute respiratory failure.(Okamoto K, Sato T, Morioka T: Airway occlusion pressure (P_0.1)—A useful predictor for the weaning outcome in patients with acute respiratory failure—. J Anesth 4: 95–101, 1990)     

Endocrine and hemodynamic changes during liver surgery in patients with compensated liver cirrhosis

The purpose of this study was to determine hormonal levels in compensated liver cirrhotic patients under general anesthesia before and after liver surgery. We measured plasma norepinephrine, epinephrine, arginine vasopressin, and aldosterone levels and renin activity in non-cirrhotic and compensated cirrhotic patients undergoing liver resection after induction of anesthesia but before skin incision and after the end of operation but before discontinuation of nitrous oxide. We simultaneously measured hemodynamic variables. Plasma levels of norepinephrine (P 0.001), epinephrine (P 0.001), arginine vasopressin (P 0.05), renin (P 0.05) and aldosterone (P 0.001) significantly increased after completion of surgery compared with those before incision in both groups. There was a significant positive correlation between plasma renin and aldosterone (r = 0.56, P 0.01) levels in non-cirrhotics, but no correlation was observed in cirrhotics; and there was a significant positive correlation between plasma norepinephrine and arginine vasopressin (r = 0.45, P 0.05) levels in non-cirrhotics, but no correlation in cirrhotics. Cardiac index and arterial pressure increased after the end of operation (P 0.05). This increase after the operation was the same between cirrhotic and non-cirrhotic groups. There were no changes in heart rate, mean pulmonary arterial pressure, and pulmonary capillary wedge pressure after the end of operation. We conclude that hemodynamic and endocrinological changes were similar between compensated cirrhotic patients and non-cirrhotic patients during liver surgery. Endocrine changes might partly explain the hemodynamic changes during surgery.(Maruyama K, Sakakura S, Nishimura K, et al.: Endocrine and hemodynamic changes during liver surgery in patients with compensated liver cirrhosis. J Anesth 7: 157–166, 1993)     

Effects of withdrawal of phasic lung inflation during normocapnia and hypercapnia on the swallowing reflex in humans

Purpose This study was done to test the hypothesis that hypercapnia has a direct, inhibitory effect on swallowing.Methods We investigated changes in the frequency and timing of repeated swallows induced by continuous infusion of water into the pharynx before, during, and after transient airway occlusion at normocapnia and hypercapnia in 12 healthy volunteers. Hypercapnia was induced by adding a dead space. Ventilation was monitored using a pneumotachograph, and swallowing was identified by submental electromyogram.Results We found that hypercapnia decreased the frequency of swallows (8.2 ± 3.7 vs 11.4 ± 5.3 swallows·min^–1 [mean ± SD]: hypercapnia vs normocapnia; P 0.05), together with a loss of the preponderant coupling of swallows with expiratory phase observed at normocapnia. We also found that the withdrawal of phasic lung inflation produced by airway occlusion at end-expiration suddenly increased the swallowing frequency, both at normocapnia (from 11.4 ± 5.3 to 16.7 ± 3.7 swallows·min^–1; P 0.01) and at hypercapnia (from 8.2 ± 3.7 to 22.0 ± 6.7 swallows·min^–1; P 0.01). Although the degree of increased swallowing frequency during airway occlusion was more prominent at hypercapnia than at normocapnia (P 0.05), the distribution of the timing of swallows in relation to the phase of the respiratory cycle during airway occlusion at hypercapnia was similar to that during airway occlusion at normocapnia.Conclusion The results of our study strongly suggest that the attenuation of the swallowing reflex during hypercapnia is not due to the direct, inhibitory effect of CO₂ on the swallowing center, but, rather, is due to the increased inhibitory influence of a lung-volume-related reflex.     

Standardization of Ischemic Hepatic Failure in Pigs as a Model for Bioartificial Liver Assessment

Purpose. A standard protocol of ischemic liver failure in pigs was examined to establish a system for assessing the efficacy of a bioartificial liver, based on clinical practice. Methods. The portal blood flow was extracorporeally bypassed into the cervical jugular vein, using a centrifugal blood pump. The portal vein and hepatic artery were then ligated. Results. The maintenance protocol was established as follows: (1) the concentration of the inhaled anesthetic was decreased by 0.2% when the systolic blood pressure was 100mmHg; (2) the volume of an infusion containing 5% glucose was increased to 10ml/kg per hour when central venous pressure was 5mmHg; (3) 20ml of 50% glucose was injected intravenously when the blood glucose was 50mg/dl; (4) 2000 units of heparin was injected intravenously when the activated clotting time was 150s; (5) sodium bicarbonate was given when the blood pH was 7.3; (6) tidal volume was increased by 1ml/kg when the pCO₂ was 80mmHg; (7) oxygen was increased by 25% when the pO₂ was 100mmHg. No vasopressors were used in the experiment. Conclusion. Our protocol reduced the operating time and minimized the risk of data deviation that can arise from variations in operating techniques and individual animal conditions. This experimental model is also easy to use as a bridge to transplantation.     

Comparison of anesthetic effects of epidural and intravenous administration of buprenorphine during operation

Thirty six patients were received epidural anesthesia with or without buprenorphine (BPN) during upper abdominal surgery. They were divided into three groups of 12 patients as follows; G-I received 20ml of 1% lidocaine epidurally, G-II received 20ml of 1% lidocaine epidurally and 0.6mg BPN intravenously, G-III received 20ml of 1% lidocaine with 0.6mg BPN epidurally. Additional 5ml of 1% lidocaine was given to any patient if systolic blood pressure or heart rate increased 10% compared to control value. Trachea was intubated following anesthetic induction with thiopental. The lungs were ventilated with a mixture of N₂O/O₂ (33%) and pancuronium was used for muscle relaxation. The total required doses of lidocaine in G-II and G-III were decreased 60% compared to control group (G-I) (P 0.05). The mean period of time until the first administration of pentazocine for postoperative pain was 13 ± 10hr (mean ± SD) in G-II and 19 ± 24hr in G-III compared to 5 ± 4hr in G-I (P 0.001). The dose of the administration of pentazocine that was required for pain relief during the first 48 postoperative hr in G-III was 54 ± 10mg (mean ± SD) compared to 150 ± 21mg in G-I (P 0.02) and 106 ± 28mg in G-II (P 0.05). Recovery from anesthesia in G-III was more rapid than that in G-I (P 0.05). The Pa_{CO 2} values in G-II and G-III increased 15% compared to control group at about 4hr and 8hr after administration of BPN, but any clinical treatment was not needed for them. Nonrespiratory side effects, e.g., nausea, vomiting, fatigue and headache, were comparably common in all groups. Mild hematuria associated with acute hypotension occurred in two patients in G-II (17%) immediately after the intravenous injection of 0.6mg of BPN. The results showed that 0.6mg of BPN given epidurally demonstrated better anesthetic and more potent postoperative analgesic effects and lesser side effects than 0.6mg of BPN given intravenously in patients undergoing upper abdominal surgery.(Yonemura E, Fukushima K.: Comparison of anesthetic effects of epidural and intravenous administration of buprenorphine during operation. J Anesth 4: 242–248, 1990)     

Autologous Blood Donation Before Elective Off-Pump Coronary Artery Bypass Grafting

Purpose. Preoperative autologous blood donation reduces exposure to homologous blood transfusions in cardiac surgery. The purpose of this study was to ascertain the volume of predonated autologous blood needed to avoid homologous blood transfusion in scheduled off-pump coronary artery bypass grafting (off-pump CABG). Methods. Fifty-six patients underwent scheduled off-pump CABG between January 1999 and December 2000. These patients all donated either 400ml (group 1, n = 33) or 800ml (group 2, n = 23) of autologous blood before operation. These patients donated at a rate of 400ml per week. All patients were given an equal volume of saline solution at the time of autologous donation. Results. There were no significant differences in the mean age, mean body weight, mean preoperative hematocrit values, mean graft number, or mean volume of intraoperative blood loss between groups 1 and 2. There was a significant difference in the mean postoperative day-7 hematocrit value (33.6% ± 1.3% vs 39.3% ± 1.3%, P 0.05). The rates of avoiding homologous blood transfusion were 63.6% in group 1 and 100% in group 2 (P 0.05). Conclusions. Autologous blood transfusion is effective for reducing the homologous blood requirement. We believe that an 800-ml predonation is sufficient to avoid homologous blood transfusion in scheduled off-pump CABG; furthermore, patients with cardiovascular disease, including severe coronary artery disease, should be administered saline along with the blood donation.     

Comparison of early postoperative quality of life in minimally invasive versus conventional valve surgery

Purpose.Minimally invasive cardiac surgery (MICS), an approach in which full sternotomy is avoided and the surgical incision is minimal, has been shown to produce less postoperative discomfort and to enable earlier mobilization and discharge than conventional cardiac surgery (CCS). This study was performed to retrospectively evaluate quality of life following MICS in comparison with CCS valve surgery.Methods.Sixty-six patients scheduled for MICS and 50 patients scheduled for CCS for isolated aortic or mitral valve surgery from January 1999 to June 2001 were enrolled in the study. The clinical records for the two groups were compared across intraoperative parameters and those associated with postoperative quality of life.Results.The aortic clamp and cardiopulmonary bypass times in the MICS group were longer than those in the CCS group (144 ± 42 and 224 ± 58min vs 112 ± 21 and 179 ± 27min, P 0.001). Postoperative pain medication (rectal buprenorphine and intramuscular pethidine) was administered to 18 of the 66 MICS patients (27%), as compared with 26 of the 50 CCS patients (52%, P = 0.007). Postoperative delirium was less frequent in the MICS group than the CCS group (26% vs 44%, P = 0.039). Initial postoperative food intake and urine catheter removal were possible earlier in the MICS than in the CCS group. MICS patients had shorter stays in the intensive care unit than CCS patients (37.4 ± 7.3 vs 45.9 ± 8.7h, P 0.001).Conclusion.Although longer aortic clamp and cardiopulmonary bypass times remain a problem in MICS procedures, our results suggest that MICS, as compared with CCS, facilitates earlier recovery of daily activities and provides improved quality of life in the early postoperative period.     

Serum Levels of Tissue Inhibitor of Metalloproteinases-1 (TIMP-1) in Colorectal Cancer Patients

Purpose Expression of tissue inhibitor of metalloproteinases (TIMP)-1 in colorectal cancer tissue is known to be related to disease progression; however, the clinical significance of measuring the blood level of TIMP-1, which we evaluate herein, has not yet been clarified.Methods The serum level of TIMP-1 was measured by a one-step enzyme immunoassay in 123 patients who underwent resection of primary colorectal cancer.Results An elevated level of serum TIMP-1 was associated with advanced Dukes stage (P = 0.03), greater diameter of the primary tumor (P = 0.03), more lymph node metastasis (P = 0.04), and liver metastasis (P 0.001). There was a weakly positive correlation between the serum carcinoembryonic antigen (CEA) level and the serum TIMP-1 level. In patients who underwent potentially curative resection, the disease-free survival was not different between those with a high TIMP-1 level (203.5ng/ml, n = 32) and those with a low TIMP-1 level (203.5ng/ml, n = 66, P = 0.62). In patients with Dukes stage D cancer who underwent noncurative resection, the survival times were not different between those with a high TIMP-1 level (n = 13) and those with a low TIMP-1 level (n = 10, P = 0.20).Conclusions Elevated levels of serum TIMP-1 reflect the extent of colorectal cancer, without a close correlation with the serum CEA level. These findings suggest that measuring the serum TIMP-1 level would not help to predict the prognosis of patients with colorectal cancer.     

Prostaglandin E1 reduces blood loss during and after resection of lumbar herniated disc

Controlled hypotension was employed during resection of lumbar herniated disc on 10 patients. Prostaglandin E₁ (PG) was used as a hypotensive agent. The systolic blood pressure was lowered less than 100mmHg in the hypotensive group. The average blood loss during surgery was 95 ± 41ml for the hypotensive group compared with 154 ± 81ml for the normotensive group (P 0.05). The blood loss after surgery was also significantly less in the hypotensive group than in the normotensive group (P 0.05). We conclude that PG is an effective hypotensive agent on blood loss during and after surgery.(Kashimoto S, Nakamura T, Yamaguchi T: Prostaglandin E₁ reduces blood loss during and after resection of lumbar herniated disc. J Anesth 6: 294–296, 1992)     

Significance of Serum Atrial and Brain Natriuretic Peptide Release After Coronary Artery Bypass Grafting

Purpose. The aim of this study was to examine whether serial changes in endogenous levels of brain natriuretic peptide (BNP) and atrial natriuretic peptide (ANP) were associated with clinical status after coronary artery bypass grafting (CABG).Methods. Serial blood samples were collected from 14 patients preoperatively, 2, 5 and 8h after cardiopulmonary bypass, then up to 7 days postoperatively. Follow-up was done 2 years later.Results. We found a significant increase from the preoperative values in ANP and BNP concentrations on postoperative days 1 and 3 (P 0.001). The elevated BNP concentration correlated with the preoperative values (r² = 0.824, P = 0.0005). Retrospectively, the BNP concentrations after surgery in the patients who suffered cardiac events within 2 years were significantly higher than those in the patients free of cardiac events (P = 0.0023).Conclusion. The BNP concentration after CABG was found to be corrected with interim clinical status after surgery. Thus, it may be necessary for patients with a high postoperative BNP concentration to be closely monitored for coronary events.     

Insulin-like growth factor-I increases p21 expression and attenuates cisplatin-induced acute renal injury in rats

Background Exogenous insulin-like growth factor-I (IGF-I) promotes recovery from ischemic renal injury, but its effect on cisplatin (CDDP)-induced nephrotoxicity and its mechanisms for the attenuation of renal injury are unknown.Methods We administered recombinant human IGF-I (rhIGF-I, 150µg/day, i.p.) once a day 24h prior to and after CDDP (5mg/kg, i.v.) injection in rats.Results The rhIGF-I treatment significantly decreased serum creatinine (0.92 ± 0.11 vs 1.50 ± 0.15mg/dl; P 0.05), the tubular damage score, and the ratio of apoptotic cells to tubular epithelial cells in the outer stripe of the outer medulla on day 5 (P 0.05). rhIGF-I significantly increased the numbers of p21-positive nuclei (5.15 ± 0.19 vs 3.45 ± 0.42/×400 high-power field (HPF); P 0.05) and proliferating cell nuclear antigen (PCNA)-positive nuclei (28.61 ± 1.89 vs 18.26 ± 2.14/×400 HPF; P 0.05), but decreased the number of cyclin D1-positive cells (3.3 ± 0.3 vs 6.3 ± 1.7/×400 HPF; P 0.05) on day 3. rhIGF-I did not alter 5-bromo-3-deoxyuridine (BrdU) incorporation.Conclusions Our findings suggested that rhIGF-I increased renal p21 and PCNA expression, but reduced cyclin D1 expression in CDDP-treated kidneys. Exogenous rhIGF-I may ameliorate renal damage, in part by stopping the cell cycle at G1/S phase.     

N-Acetylcysteine for Preventing Pump-Induced Oxidoinflammatory Response During Cardiopulmonary Bypass

Purpose To investigate the effect of N-acetylcysteine on preventing pump-induced oxidoinflammatory response during cardiopulmonary bypass (CPB).Methods Forty patients undergoing coronary artery bypass grafting (CABG) were randomly divided into a study group (n = 20), given 50mgkg^–1 N-acetylcysteine intravenously for 3 days, and a control group (n = 20) given saline. Serum samples were collected for measurement of myeloperoxidase (MPO), malondialdehyde (MDA), interleukin-6, ₁-acid glycoprotein (AAGP), and C-reactive protein (CRP) during surgery and postoperatively.Results The MPO and MDA values showed a similar pattern during and after CPB in the study group, with significantly less variance than in the control group. Interleukin-6 showed similar patterns in the two groups, but the data from 30min after the start of CPB and from 6h post-CPB were significantly different. The AAGP and CRP values were both elevated during CPB in the two groups without a significant difference, but 6 and 24h post-CPB, the values were significantly higher in the control group than in the study group.Conclusions N-Acetylcysteine decreased pump-induced oxidoinflammatory response during CPB, suggesting that it could be a novel therapy for assisting in the prevention of CBP-induced oxidoinflammatory damage.     

Evaluation of conventional weaning criteria in patients with acute respiratory failure

We evaluated the reliability of conventional weaning criteria from a ventilator during 33 weaning trials on 25 patients with acute respiratory failure (ARF). Of 13 criteria, a ratio of maximal voluntary ventilation to minute ventilation (MV) 2, a vital capacity 12ml·kg^–1, a spontaneous respiratory rate 25 breaths·min^–1, and a MV 10l·min^–1 appeared to be useful for predicting successful weaning outcome. However, even using those criteria, there were many falsely-negative cases. The alveolar-arterial P_{O 2} gradient 350mmHg at an Fi _{O 2} 1.0 was not useful as a predictor of weaning outcome. The present study demonstrates that conventional criteria are frequently inaccurate for predicting weaning outcomes and suggests that the use of some of these criteria may unnecessarily prolong the length of ventilator support. Since ventilation of most patients with poor oxygenation can be successfully discontinued by placing them on a continuous positive airway pressure system, these results suggest that the improvement of oxygenation is not an indispensable prerequisite for weaning from mechanical ventilators.(Okamoto K, Iwamasa H, Dogomori H, et al.: Evaluation of conventional weaning criteria in patients with acute respiratory failure. J Anesth 4: 213–218, 1990)