Clinical significance of natriuretic peptides and cyclic GMP in hemodialysis patients with coronary artery disease

BACKGROUND: Plasma concentrations of atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP) and cyclic guanosine monophosphate (cGMP) are suitable markers of 'dry body weight' (DW) in hemodialysis (HD) patients. However, it is still unknown whether these markers can be applied to patients with renal failure and coronary artery disease (CAD). We examined the reliability of these peptides as volume markers in HD patients with CAD. We also assessed the relationship between natriuretic peptides and indices of left ventricular (LV) function. METHODS: Plasma concentrations of ANP, BNP and cGMP were determined before and after HD in patients with CAD (group 1, n = 19, mean age 63 +/- 12 years) and were compared with those of patients without cardiac disease (group 2, n = 20, age 61 +/- 15 years). Using data obtained by cardiac catheterization, we examined the relationship between natriuretic peptides and indices of LV function in HD patients with CAD. RESULTS: Baseline ANP (244 +/- 205 pg/ml), BNP (713 +/- 928 pg/ml) and cGMP (29.6 +/- 21.6 pmol/ml) were significantly higher in group 1 than in 11 healthy volunteers (18.6 +/- 9.9 pg/ml, 7.7 +/- 7.6 pg/ml, cGMP 8.9 +/- 4.9 pmol/ml, respectively). HD significantly reduced plasma ANP (87 +/- 75 pg/ml) and BNP (477 +/- 702 pg/ml) although they were still above normal control. HD reduced plasma cGMP (7.2 +/- 4.5 pmol/ml) to normal values, suggesting the elimination of cGMP across the dialyzers. Baseline levels of ANP, BNP and cGMP in group 2 were less than those of group 1 but higher than the control. HD reduced natriuretic peptides in group 2 to levels lower than those in post-HD group 1. After HD, there was no significant correlation between reductions in body weight and changes in ANP or BNP. Baseline ANP and BNP levels closely correlated with pulmonary artery pressure, pulmonary artery wedge pressure, left ventricular end-diastolic pressure and left ventricular ejection fraction. A significant correlation was observed between BNP levels and the severity of CAD. CONCLUSION: ANP, BNP and cGMP seem to be a useful markers for fluid overload but not for DW in HD patients with CAD. Plasma ANP and BNP might be useful markers for left ventricular function.     

Perioperative plasma concentrations of atrial and brain natriuretic peptides in patients undergoing hip arthroplasty

Acute hypotension, transient hypoxaemia and elevation of pulmonary artery pressure are well known to occur during cemented arthroplasty. The aim of this prospective clinical study was to characterize the relationship between plasma concentrations of atrial and brain natriuretic peptides (ANP, BNP), and changes in blood pressure in patients undergoing hip arthroplasty. Elevated ANP and BNP levels may be markers of inadequate myocardial reserve. We measured plasma ANP and BNP levels before the operation and 20 minutes after the cementing in 18 patients (54-90 yr). We defined a hypotensive response after cementing as a decrease in systolic blood pressure of more than 15 mm Hg below the pre-cementing value. In the hypotensive group, preoperative values of ANP were 123 +/- 48.5 pg/ml and BNP, 138 +/- 71.7 pg/ml. These values are significantly greater than those in the normotensive group (ANP 35.9 +/- 7.7, and BNP 17.2 +/- 3.2 pg/ml). High preoperative values of ANP and BNP are associated with more hypotension during cemented arthroplasty and could provide an indication of which patients are at risk of this complication.     

Post-thoracotomy analgesia: epidural vs intravenous morphine continuous infusion

BACKGROUND: We compared thoracic morphine epidural analgesia (TEA) and I.V. analgesia (IVA) with morphine, in respect to the time to extubation, the quality of postoperative analgesia, side effects, complications, postoperative hospital length of stay in patients having thoracotomy lung resection. METHODS: We prospectively studied 563 consecutive patients, undergoing thoracotomy (lobectomy, bilobectomy or pneumonectomy), randomized in two groups: TEA 286 patients and IVA 277 patients. In the epidural group, before the induction of anesthesia, continuous infusion of 15 mg of morphine in 250 mL of normal saline at 5 mL/h was started. In the IVA group a continuous infusion of 30 mg of morphine associated with 180 mg ketorolac in 250 mL of normal saline at 5 mL/h was started before the induction of anesthesia. The pain degree was evaluated on an analogic scale by Keele modified at 1 (end of anesthesia) 6, 12, 24, and 48 postoperative hours, at rest and after movements. Data obtained were analysed by means of the analysis of variance for repeated measures. RESULTS: The time from the end of surgery to tracheal extubation was similar in both groups. Significantly lower numeric verbal pain scores at rest and after movements were found in the epidural group (p<0.001). Postop complications, nausea and vomiting were higher in the IVA group (p<0.05). Postoperative mean hospital length of stay was 9+/-4 days in TEA and 11+/-4 in the IVA group (p<0.05). CONCLUSIONS: In our study the epidural root was superior in terms of analgesia, side effects, length of stay and postoperative complications after thoracotomy.     

Ropivacaine epidural anesthesia and analgesia versus general anesthesia and intravenous patient-controlled analgesia with morphine in the perioperative management of hip replacement. Ropivacaine Hip Replacement Multicenter Study Group.

The aim of our study was to compare epidural anesthesia and analgesia (EDA) with ropivacaine versus general anesthesia followed by IV patient-controlled analgesia with morphine (GA/PCA) after hip replacement regarding pain, side effects, and discharge from the postanesthesia care unit. After ethics committee approval, randomization, and informed consent, 90 patients were enrolled. In Group EDA, epidural anesthesia (ropivacaine 10 mg/mL, 15-25 mL) was followed by an epidural infusion (2 mg/mL, 4-6 mL/h for 24 h, plus top-up doses of 6-10 mL for 48 h). GA/PCA patients received general anesthesia (isoflurane/N2O/fentanyl) followed by IV patient-controlled analgesia with morphine postoperatively. Pain was assessed by using visual analog scales (0-100 mm) at rest and during physiotherapy. Pain at rest was less in the EDA (n = 43) group than in the GA/PCA (n = 45) group (at 10 h: 11.8+/-12.9 vs. 28.4+/-17.1 [P< 0.001]; at 24 h: 14.3+/-11.7 vs. 24.0+/-17 [P<0.01]; in 48 h: 14.3+/-9.3 vs. 21.1+/-17.4 [P = 0.1]). Whereas EDA patients were deemed ready for discharge from the postanesthesia care unit earlier than GA/PCA patients (5.6+/-8.9 vs. 39.7+/-41.5 min), the actual discharge time was comparable. The median time for first passage of flatus was shorter in the EDA group than in the GA/PCA group (26 vs. 47 h). Nausea and vomiting were more common in the GA/PCA group than in the EDA group (16% vs. 28% and 11% vs. 22%, respectively), whereas hypotension (11% vs. 4%) and bradycardia (14% vs. 2%) were less frequent. Under the conditions of the present study, EDA with ropivacaine provided pain control after hip replacement superior to that provided by IV patient-controlled analgesia with morphine, particularly during the first 24 h. Both approaches to pain management were equally safe. IMPLICATIONS: Compared with general anesthesia and postoperative IV patient-controlled analgesia with morphine, epidural anesthesia and analgesia with the new local anesthetic ropivacaine enables patients to be discharged sooner from a postanesthesia care unit and provides superior pain relief during the first 24 h after hip replacement.     

Differential secretion of atrial and brain natriuretic peptide in critically ill patients

Atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) are cardiac hormones with natriuretic, vasorelaxant, and aldosterone-inhibiting properties. We analyzed the plasma of 178 critically ill patients for ANP, BNP, aldosterone, and serum sodium concentration, as well as serum and urine osmolality and sodium filtration fraction. Mean plasma concentrations of ANP and BNP were increased in critically ill patients compared with healthy controls (ANP, 14.3 +/- 5.8 pmol/L versus 8.8 +/- 3.2 pmol/L, P < 0.05; BNP, 26.2 +/- 10.7 pmol/L versus 4.6 +/- 2.8 pmol/L, P < 0.0001). The relative increases in ANP concentrations were comparable in all diseases. BNP concentrations, by contrast, showed a wider variation. The largest BNP concentrations were observed in patients who underwent cardiac surgical procedures and in patients with subarachnoid hemorrhage. ANP, but not BNP, was correlated with aldosterone levels (r = 0.4, P < 0.001), serum sodium (r = 0.42, P < 0.001), sodium filtration fraction (r = 0.3, P < 0.001), serum osmolality (r = 0.25, P < 0.01), urinary osmolality (r = -0.24, P < 0.01), and central venous pressure (r = 0.22, P < 0.01). ANP and BNP concentrations were increased in critically ill patients; however, this did not correlate with the severity of illness or mortality. Our data support a regulatory role for ANP in the maintenance of water and electrolyte balance. The physiologic role of BNP, by contrast, is less clear. ANP and BNP are not predictors for the severity of illness and mortality in critically ill patients.     

Relationships between brain natriuretic peptide, troponin I and QT dispersion in asymptomatic dialysis patients

OBJECTIVES: The relationships between increased wall stress, myocyte death, and ventricular repolarization instability in patients with heart failure were reported. DESIGN AND METHODS: The relationships between brain natriuretic peptide (BNP), a predictor of increased wall stress of hearth; troponin I (cTnI), a predictor of myocyte death; and QT dispersion (QTd), a reflection of ventricular repolarization instability were evaluated in age- and sex-matched asymptomatic 29 hemodialysis (HD) patients and 26 peritoneal dialysis (PD) patients, and the finding were compared. RESULTS: Serum BNP and cTnI levels in HD patients (722.9 +/- 907.9 pg/mL, 0.05 +/- 0.07 microg/L, respectively), just before HD, were significantly higher than those of PD patients (255.4 +/- 463.7 pg/mL, 0.02 +/- 0.02 microg/L, respectively; p < 0.05). There was no significant difference between groups with regard to corrected QTd and maximum and minimum QT intervals (p > 0.05). Serum cTnI levels were significantly and positively correlated with serum BNP levels in both dialysis groups (r = 0.447, p = 0.048). No relationship was found between plasma BNP and ECG parameters studied in both groups (p > 0.05). CONCLUSION: Increased serum cTnI levels were associated with elevated BNP levels in both dialysis groups. The increases in BNP and troponin I are more likely to reflect hypervolemia. Although CAPD patients were receiving dialysis daily and HD patients were more hypervolemic, CAPD patients have similar QTdc and accordingly a similar tendency toward arrhythmias. This suggests that factors other than electromechanical interaction may be important in determining the QT interval length in patients on dialysis.     

Usefulness of OPCAB from the viewpoint of fluctuations in the level of blood natriuretic peptides

Fluctuations in the level of blood natriuretic peptides (ANP and BNP) were compared between 41 patients who underwent conventional coronary artery bypass (CCAB) and 19 patients who underwent off-pump coronary artery bypass (OPCAB). A blood sample was collected before surgery, and 6, 12 and 24 hours; 2, 3, 5 and 7 days; and 1 month after the end of extracorporeal circulation. There were no significant differences in left ventricular ejection fraction (LVEF) before and after surgery in either group or between the two groups. On average, 3.3 +/- 1.0 bypass grafts were used for the CCAB group, and 2.2 +/- 0.8 grafts for the OPCAB group. Furthermore, the maximum postoperative creatine phosphokinase-MB (CK-MB) level for the CCAB group was 49.1 +/- 17.5 IU/l, whereas that for the OPCAB group was significantly lower at 23.2 +/- 24.8 IU/l. The preoperative level of blood ANP for the CCAB group was 24.6 +/- 19.9 pg/ml while that for the OPCAB group was 39.3 +/- 29.5 pg/ml, but there was no significant difference between the two groups. In both groups, the level of blood ANP reached a peak three days after the end of extracorporeal circulation and then decreased after that point. Although the level of blood ANP for the OPCAB group decreased to 51.4 +/- 26.4 pg/ml one month after the end of extracorporeal circulation, that for the CCAB group one month after the end of extracorporeal circulation remained significantly high at 61.3 +/- 30.6 pg/ml, when compared to that before surgery. Furthermore, the preoperative level of blood BNP for the CCAB group was 40.0 +/- 35.2 pg/ml and that for the OPCAB group was 75.5 +/- 59.7 pg/ml, but there was no significant difference between the two groups. Then, in both groups, the level of blood BNP reached a peak 2-5 days after the end of extracorporeal circulation and then decreased after that. Whereas the level of blood BNP for the OPCAB group decreased to 96.4 +/- 56.0 pg/ml one month after the end of extracorporeal circulation, that for the CCAB group one month after the end of extracorporeal circulation remained significantly high at 160.3 +/- 106.2 pg/ml when compared to that before surgery. The levels of ANP and BNP increased postoperatively for both OPCAB and CCAB groups since the following events caused a great degree of stress on the heart: general anesthesia, cardiac herniation, stabilizer compression, regional blood flow blockage and reperfusion injury. Although the level of natriuretic peptides for the CCAB group remained high one month after the end of surgical stress, that for the OPCAB group returned to near the preoperative level one month later, thus supporting the notion that OPCAB is less invasive.     

Increased circulating levels of natriuretic peptides predict future cardiac event in patients with chronic hemodialysis

BACKGROUND/AIMS: Cardiovascular events are the major determinant of the prognosis in patients with chronic hemodialysis. The present study was designed to investigate whether increased plasma levels of atrial or brain natriuretic peptides (ANP or BNP) predict future cardiac events in such patients. METHODS: Fifty-three patients undergoing chronic hemodialysis without clinical symptoms suggestive of cardiac disorders were enrolled and their blood was sampled for ANP and BNP measurements. Electrocardiograms demonstrated left ventricular hypertrophy in 28 patients but no other abnormal findings. We followed them up for 11.3 +/- 0.2 months. The endpoint was cardiac events. RESULTS: Cardiac events occurred in 13 patients (CE group). Both ANP and BNP levels were higher in CE group than in patients without cardiac events (ANP: 118 +/- 21 vs. 56 +/- 5 pg/ml, BNP: 769 +/- 204 vs. 193 +/- 25 pg/ml, respectively). Receiver operating characteristics curve revealed that the cut-off levels of ANP and BNP were 58 and 390 pg/ml, respectively. Using the Kaplan-Meier method, the incidence of cardiac events was significantly greater in patients with higher levels of ANP (50.0 vs. 0.0%) or BNP (72.7 vs. 11.9%) than in those with lower levels of the peptides. CONCLUSIONS: Elevated levels of ANP or BNP indicate an increased risk of cardiac events and these peptides are clinically useful to predict cardiac events in patients with hemodialysis.     

Effects of intrathecal sufentanil on plasma oxytocin and cortisol concentrations in women during the first stage of labor

BACKGROUND AND OBJECTIVES: Intrathecal sufentanil provides analgesia comparable to epidural bupivacaine for the first stage of labor. Both epidural local anesthetics and intrathecal opioid reduce some parameters of the neuroendocrine response to labor pain and the reflex release of oxytocin in animals. In humans, epidural local anesthetics only reduce the spurt release of oxytocin. This study compared the effect of intrathecal sufentanil and epidural bupivacaine administration on the plasma concentration of oxytocin and cortisol in women with labor pain during the first stage of labor. METHODS: Thirty healthy parturients requesting analgesia were enrolled in this randomized and open-label study. Each patient was in spontaneous labor at greater than 5 cm cervical dilatation. Using a combined spinal and epidural technique, patients received either intrathecal sufentanil 10 microg (SUF = intrathecal sufentanil group) or epidural plain bupivacaine 0.25%, 12 mL (BUPIV = epidural bupivacaine group). Analgesia was assessed using a visual analog scale, and blood samples for oxytocin and cortisol plasma concentration measurements were collected immediately before analgesia and 15, 30, 60, and 90 minutes after induction of the analgesia. Plasma cortisol and oxytocin concentrations were determined by specific radioimmunoassay. The values were expressed as mean +/- SEM. RESULTS: Intrathecal sufentanil provided faster and more complete analgesia within 15 and 30 minutes of its administration, compared with epidural bupivacaine. Plasma oxytocin concentrations were similar in the 2 groups before analgesia (7.24 +/- 2.1 and 6.6 +/- 3.1 pg/mL SUF and BUPIV, respectively). It decreased significantly in the SUF and increased in the BUPIV after analgesic administration. Cortisol concentrations were elevated in both groups before analgesia (51.6 +/- 5.3 and 54.2 +/- 4.8 microg/dL SUF and BUPIV, respectively). Both analgesic treatments significantly decreased the plasma cortisol levels. CONCLUSIONS: Intrathecal sufentanil analgesia decreases plasma concentrations of oxytocin and cortisol in women with labor pain during the first stage of labor, but epidural bupivacaine only reduced the cortisol concentration.     

Pre- and intraoperative epidural ropivacaine have no early preemptive analgesic effect in major gynecological tumour surgery

PURPOSE: Thoracic epidural analgesia (TEA) is an established technique for postoperative pain relief after major abdominal surgery. However it is still under discussion whether pre-incisional TEA can reduce postoperative pain perception or postoperative analgesic consumption. METHODS: The present prospective, randomized, double-blind study was performed to investigate the effects of intra- and postoperative TEA vs only postoperative TEA using ropivacaine 0.375% in 30 women scheduled for major abdominal tumour surgery. Prior to induction of general anesthesia patients received an epidural bolus of 10 mL saline in Group I (GI) and 10 mL ropivacaine 0.375% in Group II (GII) followed by an infusion of 6 mL x hr(-1) of the respective solution during surgery. Postoperatively all patients received an epidural infusion of 6 mL x hr(-1) ropivacaine 0.375% during 24 hr followed by patient controlled epidural analgesia for the next 72 hr. Operative data, dynamic pain scores, consumption of local anesthetics and standardized supplemental analgesics were analyzed. RESULTS: No difference was seen between groups with respect to the amount of required postoperative local anesthetics and supplemental analgesics, pain scores and side effects during the first 96 hr following surgery except a reduction of intraoperative sufentanil consumption (GI: 143.2 +/- 52.6 vs GII: 73.3 +/- 32.6 microg, P < 0.001). CONCLUSION: Intraoperative TEA with ropivacaine 0.375% did not significantly reduce the amount of analgesics required after major abdominal gynecological tumour surgery.     

Atrial natriuretic peptide in diabetic and nondiabetic patients with and without heart transplantation

BACKGROUND: Natriuretic peptides are useful markers for risk stratification of patients with heart disease. However, conflicting results have been reported about circulating atrial natriuretic peptide (ANP) concentration in heart transplant recipients. METHODS: To ascertain the effects of diabetes and acute insulin administration on plasma ANP concentrations in a model of heart denervation, we studied 12 diabetic (D-OHT) and 6 nondiabetic heart-transplanted (OHT) patients using the euglycemic-hyperinsulinemic clamp and oral glucose tolerance tests. Five patients with type 2 diabetes without heart transplantation (D) and 9 healthy subjects (NOR) matched for anthropometric features served as the controls. RESULTS: Means baseline plasma ANP concentration was higher in D-OHT (82 +/- 15 pg/mL) than in OHT or NOR (27 +/- 4 or 30 +/- 5; P < .01), but was not different than D (69 +/- 12; P = .82). During the clamp plasma ANP showed similar increases in all groups (49 +/- 4, 39 +/- 3, 59 +/- 4, and 49 +/- 3% in D-OHT, OHT, D, and NOR; P < .02 vs basal, P = NS among groups). Plasma osmolarity and catecholamines were also not different among groups and did not increase during the clamp. Fasting plasma ANP concentrations correlated with plasma glucose concentrations measured 120 minutes after oral glucose tolerance testing. CONCLUSIONS: Among heart transplantation recipients fasting plasma ANP concentrations were not different at 5 to 6 years after the surgical procedure than in nondiabetic controls. Increased ANP concentrations were observed among recipients with diabetes and among nontransplanted diabetic patients. Although the insulin-induced increment in ANP concentrations was not different among groups, circulating ANP was strongly associated with glucose tolerance status.     

More epidural than intravenous sufentanil is required to provide comparable postoperative pain relief

The extent to which epidurally administered sufentanil acts directly on spinal opioid receptors remains controversial. We tested the hypothesis that small-dose boluses of sufentanil, given epidurally or IV, provide comparable analgesia at similar plasma sufentanil concentrations. The lipophilicity of sufentanil makes it likely to be absorbed into fat surrounding the epidural space. We therefore also tested the hypothesis that more epidural than IV sufentanil is required to produce comparable analgesia. Analgesia and plasma sufentanil concentrations were evaluated in 20 postoperative patients randomly assigned to patient-controlled epidural or IV sufentanil. Pain was evaluated with visual analog scales by blinded observers. Sufentanil doses and plasma concentrations were measured. Analgesia was similar with epidural and IV sufentanil administration. Plasma sufentanil concentrations were virtually identical in the two groups. However, significantly larger sufentanil doses were required with epidural administration: 238 +/- 50 microg vs 160 +/- 32 microg (P < 0.01). The primary mechanism by which small-dose boluses of epidurally-administered sufentanil produce analgesia seems to be systemic absorption of the drug with subsequent recirculation to the supraspinal opioid receptors. This study demonstrates that the cumulative dose of sufentanil, when administered as a small epidural bolus, is approximately 50% more than that administered IV to provide comparable analgesia. This indicates that the bioavailability of epidurally-administered sufentanil is reduced and suggests that a large proportion of the drug may be absorbed into the epidural fat. IMPLICATIONS: More epidural than IV sufentanil was required to provide comparable postoperative pain relief and similar plasma sufentanil concentrations. These data suggest that when sufentanil is administered in small-dose boluses, much of the drug is absorbed into the epidural fat and that the primary mechanism by which epidurally administered sufentanil produces analgesia is via systemic absorption.     

Mature form of adrenomedullin is a useful marker to evaluate blood volume in hemodialysis patients

We investigated the pathophysiological significance of the mature form of adrenomedullin (AM) in hemodialysis (HD) patients. Thirty-nine HD patients were enrolled and divided into two groups: those undergoing ultrafiltration (UF) during an HD session, group I; and those not undergoing UF, group II. We measured mature AM, atrial natriuretic peptide (ANP), endothelin-1, nitric oxide, cyclic guanosine 3',5'-monophosphate, and catecholamine levels at 1-hour intervals during HD sessions. On-line optical measurement of hematocrit was used to estimate change in blood volume during HD. In group II, blood volume did not change significantly during HD, nor did plasma mature AM concentrations estimated at the beginning and end of the HD treatment (3.0 +/- 0.3 and 2.8 +/- 0.2 fmol/mL, respectively). However, blood volume decreased significantly in group I patients (-7.3% +/- 0.6%), as did plasma mature AM concentrations (from 4.4 +/- 0.3 to 3.1 +/- 0.3 fmol/mL; P < 0.01). In contrast to mature AM, plasma ANP concentrations declined in both groups (from 193 +/- 32 to 87 +/- 14 pg/mL in group I and 67 +/- 12 to 46 +/- 8 pg/mL in group II). We conclude that mature AM is a useful marker to evaluate circulating blood volume in HD patients. Circulating blood volume may regulate the conversion of AM from the inactive to the mature form.     

Ultra-fast-track anesthesia in off-pump coronary artery bypass grafting: a prospective audit comparing opioid-based anesthesia vs thoracic epiduralbased anesthesia

PURPOSE: To examine the feasibility of immediate extubation after off-pump coronary artery bypass grafting (OPCAB) using opioid based analgesia or high thoracic epidural analgesia (TEA) and compare postoperative analgesia with continuous TEA vs patient-controlled analgesia (PCA). METHODS: One hundred consecutive patients undergoing OPCAB were included in this prospective audit. After induction of anesthesia using fentanyl 2 to 5 microg.kg(-1), propofol 1 to 2 mg.kg(-1) and endotracheal intubation facilitated by rocuronium, anesthesia was maintained using sevoflurane titrated according to bispectral index monitoring. Perioperative analgesia was provided by TEA (n = 63) at the T3/T4 interspace or T4/T5 interspace using bupivacaine 0.125% 8 to 14 mL.hr(-1) and repetitive boluses of bupivacaine 0.25% during surgery. In patients who were fully anticoagulated or refused TEA, perioperative analgesia was achieved by i.v. fentanyl boluses (up to 15 microg.kg(-1)) and remifentanil 0.1 to 0.2 microg.kg(-1).min(-1), followed by morphine PCA after surgery (n = 37). Maintenance of body temperature was achieved by a heated operating room and forced-air warming blankets. RESULTS: Ninety-five patients were extubated within 25 min after surgery (PCA, n = 33; TEA, n = 62). Five patients were not extubated immediately because their core temperature was lower than 35 degrees C. One patient was re-intubated because of agitation (TEA group); one was re-intubated because of severe pain and morphine-induced respiratory depression (PCA group). Pain scores were low after surgery, with pain scores in the TEA group being significantly lower immediately, at six hours, 24 hr and 48 hr after surgery (P < 0.05). CONCLUSION: Immediate extubation is possible after OPCAB using either opioid-based analgesia or TEA. TEA provides significantly lower pain scores after surgery in comparison to morphine PCA.     

Kontinuierliche β-Blockade mit Esmolol in Kombination mit Enoximon-Gabe

BACKGROUND: The aim of this study was to assess cardiac function in vascular surgery patients with known coronary artery disease (CAD) who received continuous perioperative beta blocker therapy with esmolol alone versus esmolol in combination with the phosphodiesterase (PDE) III inhibitor enoximone. PATIENTS AND METHODS: Over a period of 24 h, 28 patients were assigned to receive heart rate (HR) control by continuous infusion of esmolol in combination with the PDE III inhibitor enoximone (Esmolol+Enoximone group) or esmolol alone (Esmolol group; n=14). Cardiac function was assessed by the use of a pulmonary artery catheter and serial measurements of plasma troponin T (TnT) und B-type natriuretic peptide (BNP). RESULTS: The heart rate significantly decreased to the target rate of 50-60 min(-1) in both groups over the observation period. Cardiac index increased significantly only in Esmolol+Enoximone-treated patients (from 2.4+/-0.2 lxmin(-1)xm(-2) to 3.1+/-0.1 lxmin(-1)xm(-2)) and was significantly higher than in the esmolol alone group (from 2.5+/-0.2 lxmin(-1)xm(-2) to 2.4+/-0.1 lxmin(-1)xm(-2)). No patient had detectable levels of cTnT perioperatively. Peak plasma BNP concentrations were significantly increased in both groups but the highest values were measured in the esmolol alone group. CONCLUSION: Inotropic therapy with the PDE III inhibitor enoximone improves cardiac function in high risk patients with known CAD undergoing vascular surgery and also when receiving systematic heart rate control by continuous infusion of esmolol.     

The mature form of adrenomedullin correlates with brain natriuretic peptide in plasma of chronic hemodialysis patients

AIM: Adrenomedullin (AM), a hypotensive and natriuretic peptide, consists of an amidated mature form (mAM) and an intermediate form in human plasma, of which only mAM exerts biological activity. Like atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP), plasma levels of mAM are reported to be significantly elevated in hemodialysis (HD) patients, suggesting that mAM may be stimulated partly by increased body fluid volume in a manner similar to the natriuretic peptides. Here, we examined the relationship between mAM levels and ANP or BNP levels and the effect of HD on plasma mAM in HD patients. PATIENTS AND METHODS: We measured plasma levels of mAM, total AM (tAM), ANP and BNP before and after HD in patients on long-term HD (n = 22, mean age 56.3 +/- 3.2 years) using radioimmunoassay. RESULTS: Baseline mAM (2.7 +/- 0.3 fmol/ml) and tAM (23.6 +/- 2.0 fmol/ml) were significantly higher in HD patients than in healthy subjects (1.1 +/- 0.2 fmol/ml, 9.0 +/- 2.1 fmol/ml, respectively). HD significantly reduced the levels to 1.2 +/- 0.2 fmol/ml and 13.8 +/- 1.4 fmol/ml, respectively, although tAM levels were still elevated compared to healthy subjects. Similar plasma ANP and BNP levels were obtained in HD patients. There were significant correlations between mAM and tAM levels before and after HD and between HD-induced changes in mAM and tAM levels. In the pre-HD state, levels of both mAM and tAM correlated significantly with BNP levels, but the correlation of BNP with mAM was closer than that with tAM. In contrast, no correlations were observed between the 2 forms of AM and ANP. Changes in mAM levels during HD also correlated significantly with BNP but not ANP levels, although the changes in tAM did not correlate with those of the 2 natriuretic peptides. CONCLUSION: Our results suggest that the secretion/metabolism of mAM may be regulated in a manner similar to that of BNP in HD patients.     

Postoperative confusion in schizophrenic patients is affected by interleukin-6

STUDY OBJECTIVE: To investigate whether epidural analgesia with local anesthetics affects postoperative confusion in schizophrenic patients or the relationships between cortisol or interleukin-6 (IL-6) and postoperative confusion. DESIGN: Prospective, randomized study. SETTING: Hakodate Watanabe Hospital and Hirosaki National Hospital. PATIENTS: 105 patients who were scheduled to undergo abdominal surgery with general anesthesia. INTERVENTIONS: The schizophrenic patients were rendomly divided into two groups: patients in Group A received epidural anesthesia and patients in Group B did not receive epidural anesthesia. MEASUREMENTS AND MAIN RESULTS: Postoperative confusion during the first 48 hours after the end of operation occurred in 7 of 33 patients (21%) in Group A and 10 of 33 patients (30%) in Group B. There were no significant differences in the frequency of postoperative confusion between Groups A and B. Plasma cortisol concentrations in schizophrenic patients in Group A were significantly lower 15 minutes after incision and the end of surgery than those levels of patients in Group B; however, there was no significant difference between groups in plasma cortisol concentrations after anesthesia. Plasma IL-6 concentrations (51.7 +/- 22.0 and 31.4 +/- 8.2 pg mL(-1)) in patients with postoperative confusion at the end of surgery and 24 hours after surgery were significantly higher than those levels (34.4 +/- 16.2 and 16.9 +/- 7.7 pg mL(-1)) in patients without postoperative confusion. CONCLUSIONS: Epidural anesthesia does not significantly decrease the frequency of postoperative confusion in schizophrenic patients. Plasma IL-6 concentrations at the end of the operation and 24 hours after surgery in schizophrenic patients with postoperative confusion were significantly higher than those concentrations in patients without postoperative confusion.     

A-type and B-type natriuretic peptides in cardiac surgical procedures

This study was performed to determine the secretion pattern and prognostic value of A-type (ANP) and B-type (BNP) natriuretic peptide in patients undergoing cardiac surgical procedures. We measured ANP and BNP in patients undergoing coronary artery bypass grafting (CABG) with (n = 28) or without (n = 32) ventricular dysfunction and in patients undergoing mitral (n = 21) or aortic (n = 24) valve replacement, respectively. Postoperative mortality was recorded up to 730 days after operation. ANP, but not BNP, concentrations were closely associated with volume reloading of the heart after aortic cross-clamp in all patients. The secretion pattern of BNP during surgery was much less uniform. BNP, but not ANP, concentrations correlated with aortic cross-clamp time (r(2) = 0.32; P = 0.006) and postoperative troponin I concentrations (r(2) = 0.22; P = 0.0009) in bypass patients, and preoperative BNP increases were associated with a more frequent postoperative (2-yr) mortality in these patients. Markedly increased preoperative BNP concentrations in mitral (3-fold) and aortic (14-fold) valve disease patients did not further increase during cardiopulmonary surgery. The data suggest that ANP is primarily influenced by intravascular volume reloading of the heart after cross-clamp, whereas the secretion of BNP is related to other factors, such as duration of ischemia and long-term left ventricular pressure and/or excessive intravascular volume. BNP, but not ANP, was shown to be a mortality risk predictor in patients undergoing CABG. IMPLICATIONS: A-type natriuretic peptide is primarily influenced by volume reloading of the heart after cross-clamp, whereas the secretion of B-type natriuretic peptide (BNP) is related to the duration of ischemia and long-term left ventricular pressure and/or volume overload. Preoperative BNP, but not postoperative BNP, concentrations predict long-term outcome after coronary artery bypass grafting.     

Reversible cardiac sympathectomy by high thoracic epidural anesthesia improves regional left ventricular function in patients undergoing coronary artery bypass grafting: a randomized trial

HYPOTHESIS: To evaluate the effects of high thoracic epidural anesthesia (TEA) on global and regional myocardial function and on perioperative coronary risk in patients undergoing coronary artery bypass grafting. DESIGN, SETTING, AND PATIENTS: Prospective and randomized clinical trial blinded for the primary outcome measure of 73 patients scheduled for coronary artery bypass grafting who had a left ventricular ejection fraction of 50% or more conducted from February 1, 2000, through August 31, 2000, at University Hospital, Münster, Germany. INTERVENTIONS: Of 73 randomized patients, 37 were control subjects (who received general anesthesia only) and 36 were in the group who received general anesthesia and high TEA. MAIN OUTCOME MEASURES: The primary outcome measure was regional left ventricular function after myocardial revascularization, assessed by transesophageal echocardiography. We further determined the plasma concentrations of cardiac troponin I and atrial and brain natriuretic peptides. Secondary outcome measures were postoperative complications recorded to 14 days and mortality recorded to 720 days. RESULTS: High TEA was effective in all patients of this group, the somatosensory block extended from T1 through T7 vertebrae. Regional left ventricular function was significantly improved (mean [SD] global wall motion index, 0.74 [0.18] vs 0.38 [0.16]; P<.05), and cardiac troponin I concentrations were reduced by 72% (mean [SD], 5.7 [1.5] vs 1.6 [0.7] ng/mL, P<.05) in patients with high TEA. Natriuretic peptide concentrations peaked during reperfusion (atrial natriuretic peptide) and 24 hours after reperfusion (brain natriuretic peptide). High TEA reduced the mean (SD) peak concentrations of atrial natriuretic peptide by 54% (211 [63] vs 98 [33] ng/mL, P =.03) and brain natriuretic peptide by 43% (189 [39] vs 108 [21] ng/mL, P =.01). One of 36 patients who received high TEA and 3 of 37 controls died. CONCLUSIONS: Reversible cardiac sympathectomy by high TEA improves regional left ventricular function and reduces postoperative ischemia after coronary artery bypass grafting. These effects of high TEA may improve the long-term outcome after myocardial revascularization.     

Comparison of continuous epidural bupivacaine infusion plus either continuous epidural infusion or patient-controlled epidural injection of fentanyl for postoperative analgesia.

We compared the postoperative epidural analgesia provided by the continuous epidural infusion of bupivacaine supplemented with patient-controlled injection (PCA) of epidural fentanyl with that provided by a continuous infusion of bupivacaine supplemented with a continuous epidural infusion of fentanyl. Our patient population comprised 16 ASA physical status I or II patients undergoing laparotomy with a midline incision under general anesthesia combined with bupivacaine epidural analgesia. Post-operatively, a continuous epidural infusion of bupivacaine (0.1 mg.kg-1.h-1) was combined with epidural fentanyl given by either (a) PCA (15-micrograms bolus with a lockout interval of 12 min, n = 8) or (b) continuous infusion (1 microgram.kg-1.h-1, n = 8). In the case of inadequate pain relief in the latter group, the fentanyl infusion rate was increased by 10 micrograms/h. Analgesia evaluated by a visual analogue pain score and by a verbal pain score was similarly effective in both groups. The sedation score was also similar in both groups. The total dose of epidural fentanyl administered during the first 24 h was significantly lower in the PCA group than in the continuous infusion group (405 +/- 110 micrograms vs 1600 +/- 245 micrograms, P less than 0.001). The dose of fentanyl given during each 4-h interval ranged between 40 and 160 micrograms in the PCA group and 251 and 292 micrograms in the continuous infusion group. Clinically detectable respiratory depression was not observed in either group. In conclusion, epidural administration of 0.1 mg.kg-1.h-1 bupivacaine combined with fentanyl provides effective postoperative analgesia with a total dose of fentanyl required that is lower when fentanyl is administered by epidural PCA rather than by continuous epidural infusion.