Epidural block with ropivacaine and bupivacaine for elective caesarean section: maternal cardiovascular parameters, comfort and neonatal well-being.

OBJECTIVE: To determine cardiovascular effects and neonatal outcome of ropivacaine 0.75% and bupivacaine 0.5% for elective epidural caesarean section. RESEARCH DESIGN AND METHODS: Healthy pregnant women, scheduled for elective caesarean section, were enrolled in this randomised, double-blind study. Epidural block was obtained with 20-30 ml of ropivacaine 0.75% (Group R) or bupivacaine 0.5% (Group B) and surgery did not commence until anaesthesia was achieved bilaterally to T6. MAIN OUTCOME MEASURES: Maternal heart rate and blood pressure were assessed before the main dose of local anaesthetic and at 5-min intervals until 35 min. Neonatal umbilical pH and Apgar scores were determined after delivery. Ten, twenty and thirty minutes after the main dose, sensory and motor block characteristics were determined. Quality of analgesia was assessed by the anaesthetist, surgeon and the patient. Adverse events were recorded. RESULTS: Sixty-two patients were enrolled and the data of 60 of them were eligible for analysis: 31 in Group R and 29 in Group B. The area under the curve (AUC) for maternal heart rate decreased significantly less in Group B than in Group R (p = 0.038). Twenty-five and thirty minutes after administration of the main local anaesthetic dose, heart rate decreased significantly less in Group B than in Group R (p = 0.006 and p = 0.007). There was no difference in AUC for maternal blood pressure (p = 0.32). Repeated measurement analysis showed no difference between groups in motor block (p = 0.78) and in spread of the sensory block (lower level: p = 0.83, upper level: p = 0.88). There was no statistical difference in neonatal umbilical pH (p = 0.22) and Apgar score (p = 0.59). Multiple linear regression analysis showed a significant influence of maternal body mass index on neonatal pH (p = 0.004), but not of maternal blood pressure (p = 0.323), nor of maternal heart rate (p = 0.12). The quality of analgesia and incidence of adverse events were similar in both groups. CONCLUSIONS: Both drugs produced equally satisfactory epidural block. Although ropivacaine 0.75% resulted in a greater decrease of maternal heart rate, this effect did not influence neonatal well-being. Both ropivacaine 0.75% and bupivacaine 0.5% can therefore be recommended for epidural anaesthesia in elective caesarean section.

N-acetylcysteine prevents reactive oxygen species-mediated myocardial stress in patients undergoing cardiac surgery: results of a randomized, double-blind, placebo-controlled clinical trial.

OBJECTIVE: Reactive oxygen species have been shown to contribute to myocardial stress in patients undergoing cardiac surgery, as demonstrated by myocardial 8-iso-prostaglandin-F(2)alpha and nitrotyrosine formation. We hypothesized that the reactive oxygen species scavenger N-acetylcysteine attenuates reactive oxygen species-mediated myocardial stress in patients undergoing cardiac surgery. METHODS: Forty patients undergoing coronary artery surgery (mean age +/- SD, 66 +/- 9 years; 9 women and 31 men) were randomized to receive either N-acetylcysteine (100 mg/kg into cardiopulmonary bypass prime followed by infusion at 20 mg.kg(-1).h(-1), n = 20) or placebo (n = 20). Patients and clinical staff were blinded to group assignment. Transmural left ventricular biopsy specimens collected before and at the end of cardiopulmonary bypass were subjected to immunocytochemical staining against 8-iso-prostaglandin-F(2)alpha (primary measure) as an indicator for reactive oxygen species-mediated lipid peroxidation and nitrotyrosine (coprimary measure) as a marker for peroxynitrite-mediated tissue injury. Cardiomyocyte staining was quantitatively determined by using densitometry (in gray units). Global left ventricular function was measured on the basis of fractional area of contraction by using transesophageal echocardiography. RESULTS: Patient characteristics in both groups were comparable. The change in left ventricular cardiomyocyte staining (end of cardiopulmonary bypass--before cardiopulmonary bypass) differed significantly between groups for both primary measures: 8-iso-prostaglandin-F(2)alpha, -1.8 +/- 7.5 gray units (mean +/- SD, N-acetylcysteine group) versus 5.0 +/- 4.1 gray units (placebo group; 95% confidence interval, 2.6-11.0, P =.003); nitrotyrosine, -6.4 +/- 10.0 gray units (N-acetylcysteine group) versus 9.2 +/- 8.4 gray units (placebo group; 95% confidence interval, 9.4-21.7, P <.001). Hemodynamics and clinical outcomes were comparable in both groups. CONCLUSIONS: Reactive oxygen species scavenging with N-acetylcysteine attenuates myocardial oxidative stress in the hearts of patients subjected to cardiopulmonary bypass and cardioplegic arrest.

Ropivacaine 0.1% with sufentanil 1 microg/mL inhibits in vitro growth of Pseudomonas aeruginosa and does not promote multiplication of Staphylococcus aureus.

UNLABELLED: We investigated the effect of ropivacaine combined with sufentanil, a mixture frequently used for postoperative epidural analgesia, on the growth of Staphylococcus aureus and Pseudomonas aeruginosa at room temperature. Aliquots of suspension of S. aureus and P. aeruginosa in saline were transferred into test tubes containing either a mixture of ropivacaine 0.1% and sufentanil 1 microg/mL (R+S) or saline (SA), with the latter serving as control. At 0, 3, 6, 24, and 48 h after inoculation, 1 mL of each solution was spread over standard blood agar. The plates were incubated at 22 degrees C for 48 h, and the numbers of colony-forming units (cfu) were counted. The growth ratio for both bacterial strains was calculated as cfu time (t(n))/cfu baseline (t(0)). The primary efficacy variable was the area under the curve (AUC) in (cfu t(n)/cfu t(0)) x time, based on the growth ratios. The AUC for P. aeruginosa was significantly less in R+S than in SA (P = 0.028). Multiplication of P. aeruginosa (growth ratio >1) was observed for at least 6 h after inoculation in SA. Growth of P. aeruginosa was significantly less in R+S than in SA at 3 h (P = 0.043) and 24 h (P = 0.012) after inoculation. The AUC for S. aureus did not differ significantly between R+S and SA (P = 0.74). Neither R+S nor SA promoted multiplication of S. aureus. Forty-eight hours after inoculation, growth of S. aureus was significantly less in R+S than in SA (P < 0.0001). We conclude that R+S inhibited growth of P. aeruginosa and did not promote multiplication of S. aureus when compared with SA. IMPLICATIONS: This laboratory study demonstrated that compared with saline, ropivacaine 0.1% with 1 microg/mL of sufentanil inhibited growth of Pseudomonas aeruginosa and did not promote multiplication of Staphylococcus aureus at room temperature. With respect to bacterial infection with these two strains, the mixture seems to be safe for continuous epidural administration if prepared under aseptic conditions and after alcohol hand rub.

The continuous epidural infusion of ropivacaine 0.1% with 0.5 microg x mL(-1) sufentanil provides effective postoperative analgesia after total hip replacement: a pilot study.

PURPOSE: To assess the analgesic efficacy and functional outcome of postoperative epidural infusion of ropivacaine combined with sufentanil in a randomized, controlled trial. METHODS: Thirty-two ASA I-III patients undergoing elective total hip replacement (THR) were included. Lumbar epidural block using 0.75% ropivacaine was combined with either propofol sedation or general anesthesia for surgery. On arrival in the recovery room, the epidural infusion was commenced at a rate in mL calculated as follows: (height in cm - 100) x 0.1. Eleven patients received an epidural infusion of ropivacaine 0.1% with 0.5 microg x mL(-1) sufentanil (Group R+S0.5), ten patients ropivacaine 0.1% with 0.75 microg x mL(-1) sufentanil (Group R+S0.75), and 11 patients ropivacaine 0.1% with 1 microg x mL(-1) sufentanil (Group R+S1) over a postoperative study period of 44 hr. All patients had access to iv piritramide via a patient-controlled analgesia (PCA) device. Postel-Merle-d'Aubigné scoring system (PMA score) was assessed preoperatively, three weeks after surgery, and three months after surgery by an orthopedic surgeon blinded to study group. RESULTS: Motor block was negligible in all three groups. After eight hours of epidural infusion, sensory block had regressed completely in all patients. There was no significant difference with regard to visual analogue scale (VAS) scores (at rest: P = 0.55, on movement: P = 0.63), consumption of rescue medication (P = 0.99), patient satisfaction (P = 0.22), and the incidence of adverse events. All treatment regimens provided effective postoperative analgesia with only a minimal use of supplemental opioid PCA. There was no difference between groups regarding orthopedic PMA score (pain: P = 0.24, mobility: P = 0.65, and ability to walk: P = 0.44). CONCLUSION: Ropivacaine 0.1% with 0.5 microg x mL(-1) sufentanil for postoperative analgesia after THR provides efficient pain relief and, compared with 0.75 and 1 microg x mL(-1) sufentanil, reduces sufentanil consumption without compromise in patient satisfaction, VAS scores, and functional outcome.

Large-dose hydroxyethyl starch 130/0.4 does not increase blood loss and transfusion requirements in coronary artery bypass surgery compared with hydroxyethyl starch 200/0.5 at recommended doses.

BACKGROUND: Hydroxyethyl starch (HES) 130/0.4 may impair blood coagulation less than other HES solutions and, thus, may be used at larger doses without increasing the risk of postoperative bleeding. This study tested the hypothesis that volume replacement with 6% HES 130/0.4 at a dose of up to 50 ml/kg does not increase blood loss and transfusion requirements in elective coronary artery bypass surgery compared with 6% HES 200/0.5 at a dose of up to 33 ml/kg. METHODS: One hundred twenty adult patients scheduled for elective coronary artery bypass surgery were randomized to receive up to 50 ml/kg of 6% HES 130/0.4 or up to 33 ml/kg of 6% HES 200/0.5 for volume replacement during surgery and until 24 h thereafter. Volume requirements in excess of the respective maximum dose of HES were treated with gelatin. Colloid use was at the discretion of the attending physicians and not dictated by protocol. The primary outcome variable was chest tube drainage volume during the first 24 h after surgery. RESULTS: The data from 117 patients (HES 130/0.4, 59 patients; HES 200/0.5, 58 patients) who completed the study according to protocol were analyzed. The median volumes of HES administered were 49 and 33 ml/kg in the HES 130/0.4 and HES 200/0.5 groups, respectively (P < 0.001). Consequently, patients in the HES 130/0.4 group required less gelatin in addition to HES than those in the HES 200/0.5 group (medians: 7 ml/kg vs. 20 ml/kg, P < 0.001). The combined volumes of HES and gelatin were similar for both groups (P = 0.21). The 24-h chest tube drainage (medians: 660 ml vs. 705 ml, P = 0.60) did not differ significantly between the groups, nor did transfusion outcome. CONCLUSION: Six percent HES 130/0.4 at a median dose of 49 ml/kg did not increase blood loss and transfusion requirements in coronary artery bypass surgery compared with 6% HES 200/0.5 at a median dose of 33 ml/kg.

Current practice in postoperative epidural analgesia: a german survey.

UNLABELLED: We surveyed current German practice in postoperative epidural analgesia (EA). Of 300 questionnaires sent anonymously, 147 (49%) were returned fully completed. A 24-h acute pain service (APS) was offered in 41% of German hospitals. Seventy percent of the large teaching hospitals (>1000 beds) offered an APS, whereas just 9% of the hospitals of <500 beds provided an APS. Small-size hospitals (<200 beds) preferred ropivacaine as the local anesthetic (LA) in contrast to large teaching hospitals using more bupivacaine than ropivacaine. In the general ward setting, 36% of the respondents used plain LA, and 64% combined the LA with an opioid. If ropivacaine was used, 0.2% was the most popular concentration (78%), combined with morphine (17%), fentanyl (14%), or sufentanil (75%). If bupivacaine was used, 0.25% was the preferred concentration (30%), combined with morphine (40%), fentanyl (8%), or sufentanil (60%). On wards, 58% of German anesthetic departments used continuous epidural infusion, 57% bolus doses, and 20% patient-controlled EA mode. We conclude that the availability of a 24-h APS (41%) in German hospitals corresponds favorably to international data. EA with the combination of LAs and opioids was the most common modality in the ward setting. IMPLICATIONS: We surveyed current German practice in postoperative epidural analgesia. We found that the availability of a 24-h acute pain service (41%) in German hospitals corresponds favorably to international practice. Epidural analgesia with the combination of local anesthetics and opioids was the most common modality in the ward setting.

A randomized crossover trial of IV fluid replacement versus no fluid replacement in autologous blood donors with cardiovascular disease.

BACKGROUND: The aim of this study was to compare the incidence of arterial hypotension in response to autologous blood donation with and without simultaneous IV fluid replacement in 60 patients with cardiovascular disease. STUDY DESIGN AND METHODS: Each patient donated two 500 mL units of blood at an interval of 7 days. Following random allocation within a two-stage crossover design, either the first or second unit was collected with a simultaneous IV infusion of 500 mL of HES. Patients receiving IV fluid replacement during their first donation did not receive any fluid replacement during their second donation and vice versa. Starting before phlebotomy, arterial blood pressure was measured oscillometrically every 5 minutes until 30 minutes after donation. Hypotension was defined as at least one decrease of more than 20 percent from baseline in systolic blood pressure. RESULTS: A decrease of more than 20 percent from baseline in systolic blood pressure occurred in 2 of the 60 patients (3%) during the donations with IV fluid replacement compared with 55 of the 60 patients (92%) during the donations without IV fluid replacement (p < 0.0001, McNemar's test). No severe reaction to blood donation was observed in any patient, regardless of whether IV fluids had been administered. CONCLUSION: Isovolemic IV fluid replacement was useful in preventing arterial hypotension in autologous blood donors with cardiovascular disease. Its effect on the safety of the autologous blood donation process remains to be established.

Human error: the persisting risk of blood transfusion: a report of five cases.

UNLABELLED: It is common experience that virus transmission, particularly transmission of the human immunodeficiency virus (HIV), is a principal concern of patients and physicians regarding blood transfusion (1). Many physicians are probably unaware that transfusion-transmitted HIV infection is approximately 50 to 100 times less likely to occur than transfusion error (2-4). This misconception may have been encouraged by the scarcity of reports on transfusion error relative to the tremendous public attention focused on HIV infection. We present five cases illustrating how anesthesiologists, intensivists, and emergency physicians are particularly vulnerable to the risk of administering blood to the wrong recipient. All five cases were collected during a 4-yr period. Transfused units of packed red cells totaled approximately 50,000 U during this period in our department. IMPLICATIONS: Human error leading to the transfusion of blood to an unintended recipient is a major source of transfusion-related fatalities. We report five cases that highlight some specific areas in which transfusion error is likely to occur.