[Changes in cytokines during perioperative period of hip arthroplasty in patients older than 80 years of age].

BACKGROUND: Elevations of plasma inflammatory cytokines are related to the surgical intervention. We have examined the circulating interleukin 6, 8 (IL-6, IL-8) and CRP responses in patients older than 80 years during orthopedic hip arthroplasty. METHODS: After taking the signed informed consent, 8 patients were enrolled in this study. All patients received standard spinal anesthesia combined with epidural catheterization. Samples were collected just before and after the surgery, and on 1st, 2nd and 7th day after the operation. RESULTS: Plasma IL-6 levels showed a significant increase on the day after surgery (5.6 +/- 3.7 vs. 52.2 +/- 24.1 pg.ml-1, mean +/- SD, P < 0.05), whereas although the levels of IL-8, increased (minimum 7.9 +/- 3.2 to maximum 70.3 +/- 80.2 pg.ml-1, mean +/- SD), the change was not significant. CRP levels were slightly elevated in the preoperative examination (2.8 +/- 3.5 mg.dl-1) and further increased on the 2nd day of surgery (8.3 +/- 5.4 mg.dl-1), but returned to a normal level on the 7th day. CONCLUSIONS: From the viewpoint of cytokines, this study showed that, although IL-8 level did not return to the preoperative value, the surgical stress of orthopedic hip arthroplasty in patients older than 80 years was almost of the same level as reported previously.

[An analysis on blood transfusion for hepatic resection].

BACKGROUND: Hepatic resection is prone to significant blood loss. Adverse effects of blood loss and transfusion mandate improvements in surgical techniques to reduce blood loss and transfusion. METHODS: We retrospectively analyzed the present status of intraoperative blood transfusion practice of 42 hepatic resections in National Kure Medical Center for the year of 2000. RESULTS: Median values for blood loss were 1355, 1708, 1415, and 2298 ml for nonanatomic, subsegmental, segmental and extended right resections, respectively. Crossmatched to transfused blood (C/T) ratios were 1.76, 1.19, 2.31, and 0.90 for nonanatomic, subsegmental, segmental and extended right resections, respectively. CONCLUSION: In general, C/T ratio of 1.5 to 2.5 has been recommended but own C/T ratios are 1.19 and 0.9 for subsegmental and extended right hepatic resection, which are lower than recommended values. It was estimated that inappropriate prediction of blood loss by several surgeons and unused maximum surgical blood order schedule (MSBOS) or type and screen (T&S) decreased these values of C/T ratio in the present analysis. We therefore conclude that MSBOS and T&S could be improved by avoiding such in appropriate prediction.

Effects of nicardipine and diltiazem on fractal features of short-term heart rate variability--application of coarse graining spectral analysis.

PURPOSE: This study was designed to investigate the effects of nicardipine and diltiazem on the fractal features of short-term heart rate variability (HRV), using coarse graining spectral analysis (CGSA). METHODS: Eighteen healthy volunteers participated in this study; they were divided into two groups according to the drug administered. Five-minute electrocardiogram and arterial pressure recordings were made during stepwise infusions of either nicardipine (0.4, 0.8, 1.6, and 3.2 microg.kg(-1).min(-1)) or diltiazem (2, 4, 8, and 16 microg.kg(-1).min(-1)) under rate-controlled breathing at 0.25 Hz. CGSA broke down the total power of the time series into harmonic (low frequency [0.0-0.15 Hz; LF] and high frequency [0.15-0.5 Hz; HF]) and nonharmonic (fractal) components. Cardiac sympathetic nervous system (SNS) and parasympathetic nervous system (PNS) activity indicators were evaluated as the ratios LF/HF and HF/TP (total spectral power), respectively. Fractal components were evaluated as %fractal and the spectral exponent beta of 1/f(beta). RESULTS: Compared with control measurements, the maximum dose of nicardipine infusion caused a significant decrease in systolic arterial pressure, a significant increase in the mean heart rate, and a significant increase in plasma norepinephrine level, findings that were associated with significant increases in %fractal and beta values (54.2 +/- 13.3 vs 75.6 +/- 9.8, and 0.86 +/- 0.22 vs 1.32 +/- 0.46, respectively; P < 0.05). PNS and SNS indicators showed decreased and increased values, respectively. Diltiazem caused a reduction in arterial pressure; however, no other parameters, including the nonharmonic components of HRV, were affected by this drug. CONCLUSIONS: These findings strongly suggest that nicardipine suppresses vagal cardiac neural outflow and activate the SNS, an action which, subsequently, causes changes in the fractal features of HRV. Although diltiazem reduces arterial pressure, it preserves the basic neural balance of the autonomic nervous system in regard to heart rate control.

Effect of fentanyl on heart rate variability during mechanical ventilation.

PURPOSE: This study was performed to investigate the effect of fentanyl alone on heart rate variability (HRV) during mechanical ventilation using power spectral analysis. Arterial baroreceptor reflex was also tested with pharmacological manipulation to assess the contribution of vagal baroreceptor reflex modulation of HRV during fentanyl anesthesia. METHOD: Ten patients participated in this study. Electrocardiograms and arterial pressure were recorded prior to and during fentanyl (10 µg·kg-1) and vecuronium (0.2 mg·kg-1) anesthesia, with respiratory rate and tidal volume controlled ventilation. R-R intervals were analyzed by fast Fourier transformation, and changes in low-frequency (LF) and high-frequency (HF) power were compared. Arterial baroreceptor reflex regulation was also tested with administration of nitroglycerin (250 µg) or phenylephrine (250 µg). RESULTS: HF power was significantly reduced during anesthesia from 3.20±2.93 to 0.46±0.48 ms2·Hz-1·103 (mean±SD,P<0.05). However, LF power did not change despite increases in plasma catecholamine concentrations. The response to phenylephrine was reduced during fentanyl anesthesia from 16.6±5.7 to 9.5±5.4 ms·mmHg-1 (P<0.05), whereas the response to nitroglycerin was not affected. CONCLUSION: Our data indicate that fentanyl modulates the respiratory frequency fluctuation of HRV. This is partly caused by the effects of fentanyl on arterial baroreflex sensitivity.

Effect of high-frequency jet ventilation on heart rate variability.

We investigated the effects of high-frequency jet ventilation (HFJV) on heart rate variability in nine patients during fentanyl (10µg·kg-1) anesthesia using power spectral density analysis. ECG and arterial pressure were recorded during intermittent positive pressure ventilation (IPPV) (tidal volume 8 ml·kg-1, respiratory rate 0.25 Hz) and during HFJV [5 Hz, 2.5 kg·(cm2)-1]. The R-R interval time series obtained were analyzed by the autoregressive method, and low-frequency (LF) (0.05-0.15 Hz) power and high-frequency (HF) (0.20-0.50 Hz) power from R-R interval spectra were used for statistical comparison. LF power did not change during IPPV and HFJV (108.8±41.6 ms2 vs 105.8±22.4 ms2, mean±SE). HF power was detected during IPPV (65.1±14.3 ms2); however, it was not detected during HFJV. Plasma levels of norepinephrine and epinephrine were significantly higher during HFJV than during IPPV. The mean R-R interval, arterial pressure, and arterial blood gas data did not differ between IPPV and HFJV. These data indicate that, during fentanyl anesthesia, HFJV influences mainly the respiratory frequency fluctuation of heart rate variability, and they suggest that alteration of breathing patterns caused by HFJV might be involved, as well as elevated sympathetic neural outflow to the heart.

Spontaneous respiration should be avoided in frequency domain analysis of heart rate variability.

To determine whether spontaneous respiration is suitable for frequency domain analysis of heart rate (R-R interval) variability, we studied 15 volunteers (5 men and 10 women, aged 22-34 years) and evaluated the reproducibility of the power spectrum. Electrocardiograms were recorded for 5 min each with spontaneous and rate-controlled respiration (15 breaths·min-1), repeating the same protocol 1 week later. Fast Fourier transformation was performed using the digitized data of the R-R intervals. Mean heart rate, arterial pressure, and plasma catecholamines remained constant during the measurements. In spontaneous respiration, however, the respiratory rate was significantly lower during the second measurement (9.4±2.1 breaths·min-1) than during the first measurement (10.9±2.6 breaths·min-1), and the low-frequency power increased from 2.61±2.36 to 5.14±5.06 sec2·Hz-1·10-3. After deleting five data sets because the respiratory peak was inseparable from the low-frequency area, there was no correlation in power spectra in four out of ten subjects between the two measurements. Data were comparable for rate-controlled respiration. Since respiratory parameters strongly influenced the low- and the high-frequency R-R interval power spectra, spontaneous respiration should be avoided. A constant respiratory condition is required to interpret results of frequency domain analysis of R-R interval variability.