Postoperative intraspinal opioid analgesia after caesarean section; a randomised comparison of subarachnoid morphine and epidural pethidine.

A randomised, blinded clinical trial was performed to evaluate intraspinal opioid analgesic techniques after caesarean section. Healthy term parturients having elective caesarean section under combined spinal-epidural anaesthesia were allocated to one of three groups. Postoperative analgesia, including non-steroidal anti-inflammatory drugs, was provided using either pethidine patient-controlled epidural analgesia (group PCEA) or subarachnoid morphine 200 microg, the latter supplemented as required with patient-controlled intravenous pethidine (group SMPCIA) or oral paracetamol and codeine (group SMO). Maternal analgesia, side effects, recovery and satisfaction were assessed for 48 h. Of 144 parturients enrolled, 137 completed the study (PCEA n = 44, SMPCIA n = 45, SMO n = 48). The groups were demographically similar. All participants experienced good pain relief, including median visual analogue pain scores (0-100) with movement <40 between 0-24 h. However, pain scores were significantly lower at 8 and 12 h in those receiving subarachnoid morphine (P< 0.05). Women in groups receiving subarachnoid morphine experienced more severe pruritus (P<0.001), nausea (P< 0.001) and drowsiness (P< 0.05). Postoperative recovery of bowel function and ambulation occurred earlier in those using PCEA, although this did not appear to be of clinical significance. Patient satisfaction was similar, although women in group SMO were least likely to choose this approach again (P<0.05). We concluded that all three techniques provided effective analgesia for a prolonged period postoperatively. Better pain relief, but more opioid-related side effects, resulted from subarachnoid morphine 200 microg, and re-evaluation of reduced doses of subarachnoid morphine may be warranted.

Tricuspid valve repair in right-sided endocarditis.

BACKGROUND AND AIMS OF THE STUDY: Tricuspid valve endocarditis traditionally has been treated with either valve resection or valve replacement. To avoid implantation of foreign material in an infected area and to circumvent anticoagulation, tricuspid valve repair was applied and the results assessed. METHODS: Tricuspid valve repair was performed in five patients with right-sided endocarditis. All patients had tricuspid regurgitation grade 3-4 on preoperative transesophageal echocardiography, and developed progressive deterioration associated with heart failure. The indications for surgery were congestive heart failure, persistent sepsis, recurrent emboli, concomitant left-sided endocarditis, and fungal infection. Surgical procedures included cusp resection, annular plication and annuloplasty, pericardial patch replacement, and construction of artificial chordae. RESULTS: There were no hospital deaths and major associated morbidity. Follow up is complete at a mean of 20.4 months. There were no reoperations or cases of recurrent infections. All patients are in NYHA class I-II. Postoperative echocardiography revealed no signs of major valvular dysfunction. CONCLUSIONS: Valve repair in right-sided endocarditis is a relatively new application for repair techniques, but may become an attractive alternative to tricuspid valve excision or prosthetic valve replacement.

Session duration and the VI response function: Within-session prospective and retrospective effects.

Two experiments examined the effects of session duration on responding during simple variable-interval schedules. In Experiment 1, rats were exposed to a series of simple variable-interval schedules differing in both session duration (10 min or 30 min) and scheduled reinforcement rate (7.5 s, 15 s, 30 s, and 480 s). The functions relating response rate to reinforcement rate were predominantly monotonic for the short (10-min) sessions but were predominantly bitonic for the long (30-min) sessions, when data from the entire session were considered. Examination of responding within sessions suggested that differences in the whole-session data were produced by a combination of prospective processes (i.e., processes based on events scheduled to occur later in the session) and retrospective processes (i.e., processes based on events that had already occurred in the session). In Experiment 2, rats were exposed to a modified discrimination procedure in which pellet flavor (standard or banana) predicted session duration (10 min or 30 min). All rats came to respond faster during the short (10-min) sessions than during the first 10 min of the long sessions. As in Experiment 1, the results seemed to reflect the simultaneous operation of both prospective and retrospective processes. The results shed light on the recent controversy over the form of the variable-interval response function by identifying one variable (session duration) and two types of processes (prospective and retrospective) that influence responding on these schedules.

Obstructing cancer of the gastric antrum: palliative treatment with covered metallic stents.

A new technique, which requires a simple surgical gastrostomy without general anesthesia, is described for placement of covered expandable metallic stents. This technique was performed successfully in a patient with malignant obstruction of the gastric antrum, obviating palliative surgical resection.

Presence of immunoreactive atrial natriuretic peptides in pericardial fluid of human subjects with congenital heart diseases.

The epicardial release of immunoreactive atrial natriuretic peptides (ir-ANPs) in inside-out perfused rabbit atria has been reported. In order to determine the presence of ir-ANPs in pericardial fluid and to evaluate their biochemical characteristics, we measured the concentration of ir-ANPs in pericardial fluid obtained from the patients with congenital heart diseases during open heart surgery. Serial dilution curves made with the extrats of pericardial fluid using Sep-Pak C18 cartridges were parallel with standard curve. The concentration of ir-ANPs in pericardial fluid was significantly lower than the corresponding plasma concentration. On gel permeation and reverse-phase high performance liquid chromatography, the ir-ANPs in pericardial fluid, plasma and atrial appendage showed both high and low molecular weights. The major peak of ir-ANPs in plasma was observed at the corresponding fraction to the alpha-human ANP and considerable amount of high molecular weight form of ir-ANPs was observed in pericardial fluid. However, the major peak of ir-ANPs in atrial appendage was observed at the corresponding fraction to the rat pro-ANP. The data suggest that ir-ANPs exist both high and low molecular weight forms in pericardial fluid.