Patients undergoing mitral valve surgery are at risk of left ventricular failure in the immediate post-operative period. In order to understand better the mechanisms of post-operative haemodynamic instability, we used transoesophageal echocardiography to assess the immediate response of the left ventricle to mitral valve replacement for mitral regurgitation or stenosis. A decrease in left ventricular preload, despite adequate filling pressures, was common to both groups and suggests the presence of diastolic dysfunction. A marked impairment in global systolic pump function was observed only in the regurgitation group and correlated with the left ventricular afterload. Transoesophageal echocardiography provides valuable information on the individual changes in left ventricular function and its determinants after mitral valve replacement that are not reflected by haemodynamic measurements.

The dose-related effects of milrinone, a phosphodiesterase (PDE) III inhibitor, on the contractility of fatigued diaphragm were studied in dogs. Animals were divided into three groups of eight each. Diaphragmatic fatigue was induced by intermittent supramaximal bilateral electrophrenic stimulation at a frequency of 20 Hz applied for 30 min. After the production of fatigue, Group I received no study drug; Group II was infused with milrinone (50 mg kg−1 loading dose plus 0.2 mg kg−1 min−1 maintenance dose); Group III was infused with milrinone (50 mg kg−1 loading dose plus 0.5 mg kg−1 min−1 maintenance dose). Diaphragmatic contractility was assessed by measurement of transdiaphragmatic pressure. After the fatigue-producing period, transdiaphragmatic pressure at low-frequency stimulation (20-Hz) decreased from the prefatigued values in all groups (P < 0.05), whereas transdiaphragmatic pressure at high-frequency (100-Hz) stimulation did not change. Compared with Group I, transdiaphragmatic pressure to each stimulus increased during milrinone infusion in Groups II and III (P < 0.05). The increase in transdiaphragmatic pressure was greater in Group III than in Group II (P < 0.05). It is concluded that milrinone is associated with a dose-related effect on the contractility of fatigued diaphragm in dogs.

The treatment of tracheo-bronchial diseases with rigid bronchoscopy requires general anaesthesia without tracheal intubation. Spontaneous assisted ventilation is a safe modality of ventilation. In this study the use of remifentanil and fentanyl is compared during rigid bronchoscopy with spontaneous assisted ventilation. Ninety high-risk patients received fentanyl or remifentanil with propofol for general anaesthesia. During the maintenance fentanyl was delivered at 6.1±4.6 μg kg−1 h−1 and remifentanil at 0.15±0.07 μg kg−1min−1. The same degree of intra-operative respiratory acidosis with similar good operating conditions resulted in both groups. Patients treated with remifentanil recovered more quickly compared with those in the fentanyl group (3.8±2 vs. 10.4±9.2 min, P<0.001). In conclusion, the use of remifentanil during rigid bronchoscopy under general anaesthesia with spontaneous assisted ventilation is safe and assures good operating conditions. Moreover, remifentanil permits a more rapid recovery than fentanyl. The dose of remifentanil is higher than previously described for spontaneously breathing patients.

We studied the movement response to skin incision in 68 adult (males/females) ASA I–II patients receiving propofol±fentanyl intravenous anaesthesia using the bispectral index and 95% spectral edge frequency monitoring with an A-1050 EEG monitor. Following Ethics Committee approval, patients were randomly assigned to one of the following four treatments: Group P (n=17): propofol infusion, 1 mg kg −1 min−1 intravenous for 2 min, followed by propofol infusion, 200 μg kg−1 min−1, until skin incision; Group PF1 (n=17): fentanyl bolus, 1 μg kg−1 intravenous+ propofol infusion as in Group P; Group PF2 (n=17): fentanyl bolus, 2 μg kg−1 intravenous+ propofol infusion as in Group P; and Group PF3 (n=17): fentanyl bolus, 3 μg kg−1 intravenous+ propofol infusion as in Group P. The bispectral index and 95% spectral edge frequency were monitored continuously and recorded prior to induction of anaesthesia (base-line) and at skin incision. Twelve, 10, 4 and 4 patients responded to skin incision in Groups P, PF1, PF2 and PF3, respectively (P and PF1 vs. PF2 or PF3; P=0.0001, and 0.006). The bispectral index and 95% spectral edge frequency were significantly lower at skin incision compared with the base-line values in all the four treatment groups. However, only bispectral index values were significantly lower in the nonmovement as compared with the movement (M) category (32.6±8.9 vs. 37.4±10.3; P=0.04). Though deeper levels of hypnosis to lower bispectral index and 95% spectral edge frequency values may be effective in preventing the movement response to skin incision, provision of adequate analgesia rather than lower bispectral index and 95% spectral edge frequency (clinical maintenance) values may be more reliable for preventing the response to skin incision as bispectral index and 95% spectral edge frequency measure the hypnotic component of the anaesthetic effect. Lower bispectral index values may be more discriminatory as compared with 95% spectral edge frequency values for preventing the movement response to skin-incision.

This study was designed to examine the effect of volume loading on haemodynamic responses and regional cardiac function in dogs subjected to two infusion rates of propofol. Instrumentation was established to measure aortic and left ventricular pressures, cardiac output and myocardial segmental lengths. Measurements were taken during two successive infusion rates of propofol: 0.2 (P0.2) and 0.4 (P0.4) mg kg−1 min−1. One group (VL+) (n=6) received volume loading (dextran 40, 10 mL kg−1 h−1), the other group (VL−) (n=6) received only basal perfusion (Ringer solution, 2 mL kg−1.h−1). Regional blood flows were measured by radio-labelled microspheres. P0.4 induced a decrease in cardiac output and in dP/dtmax. End-diastolic length decreased with propofol without any difference between groups. Regional contractility was not modified by propofol or by volume loading. P0.4 decreased endocardial and epicardial blood flow in the VL-group only. Renal, small intestine and large intestine blood flows decreased in both groups with P0.4. P0.2 did not alter regional blood flows significantly. It was concluded that in this model, propofol infusion at 0.4 mg kg−1 min−1 induced splanchnic, renal and myocardial hypoperfusion in animals not submitted to a mild fluid loading. Fluid loading allowed myocardial perfusion to be maintained but could not prevent a marked decrease in splanchnic and renal perfusion.

The bispectral index, a value derived from the electroencephalogram, has been proposed as a measure of anaesthetic effect. The aim of the present study was to evaluate the bispectral index during midazolam–fentanyl anaesthesia for cardiac surgery for its possible role as a predictor of increases in systolic blood pressure during endotracheal intubation and sternotomy. After institutional approval 15 consenting patients, scheduled for elective cardiac surgery, were selected for the study. Anaesthesia was induced in all patients with a loading dose of fentanyl 7.5–10 μg kg−1, midazolam 0.15 mg kg−1 and pancuronium 0.1 mg kg−1. After a further bolus dose of fentanyl 10–12.5 μg kg−1 prior to the start of incision and sternotomy, maintenance infusion rates of fentanyl 4–6 μg kg−1 h−1 and midazolam 0.1 mg kg−1 h−1 were started and continued through surgery at the discretion of the anaesthetist and guided by the presenting clinical and haemodynamic responses. The control of anaesthesia was never based on the value of the bispectral index. The mean bispectral index value decreased from 95.7 (3.1) at base-line to 59.5 (12.0) after induction of anaesthesia and then remained below 70 throughout surgery. However, there was an important interindividual variability in bispectral index values despite standardized dosages of fentanyl and midazolam. There was no significant correlation between the bispectral index values in the pre-intubation and pre-incision period and the changes in systolic blood pressure during endotracheal intubation and sternotomy, respectively. In conclusion, the large intersubject variability in the bispectral index values should be investigated further in the light of the great variability in the clinical effects of midazolam and fentanyl. The lack of significant correlation between the bispectral index values and the haemodynamic responses suggest that the bispectral index, which is a helpful monitor of anaesthetic depth, is not a very reliable monitor of global anaesthetic adequacy during total intravenous anaesthesia with a combination of midazolam and fentanyl in cardiac surgical patients.

Local anaesthetics injected into the epidural space may deform the dural sac to a variable degree, thereby contributing to variability in the extent of the block. We investigated deformation of the lumbar dural sac after injection into the lumbar epidural space. The subjects were 26 patients with low-back pain who underwent lumbar epidurography and computed tomographic (CT) epidurography, of whom seven also underwent myelography and computed tomographic myelography. The epidural space was entered via the sacral hiatus in 24 patients and through the L5/S1 interspace in two patients. Ten millilitres of local anaesthetic was then injected into the epidural space followed by 20 mL of contrast medium. Computed tomographic epidurography was undertaken approximately 30 min after the epidural injection at the mid-vertebral and mid-discal levels from the first lumbar through to the first sacral vertebrae. The dural sac usually showed an oval or hexagonal shape on the transverse views at the first and second lumbar vertebral levels, and the shape of an inverted triangle below the level of the third lumbar vertebra. A median line of translucency was also observed on the postero-anterior epidurographic view in 25 of the 26 patients. This line was thought to be a manifestation of the dural deformation to the inverted triangle. Dural sac deformation usually shows a specific pattern, although there are individual variations. Dural deformability is an important consideration in any analysis of the spread of epidural block or of the changes of epidural pressure after epidural injection of local anaesthetics.

We have studied the apnoea time after induction with two successful drug intubating regimes, both containing remifentanil. Group 1 (n=20); propofol 2 mg kg−1 and remifentanil 2 μg kg−1 and group 2 (n=20); propofol 2 mg kg−1, remifentanil 1 μg kg−1 and lignocaine 1 mg kg−1. Intubation was possible in all 40 patients, and regarded as acceptable in 90% and 85% of patients, respectively. The median time to the return of spontaneous respiration was 487 s in group 1 and 270 s in group 2 (P < 0.05). Median end-tidal CO2 concentration at the time of the first spontaneous respiration was 7.37 kPa in group 1 and 6.3 kPa in group 2 (P < 0.05). Both groups had a decrease in heart rate after induction, but this failed to reach either clinical or statistical significance, and no patient required atropine. Similarly, there was a decrease in arterial pressure after induction in both groups (P < 0.05), but this was not deemed to be clinically significant. Only two patients in each group required ephedrine 6 mg before arterial pressure was restored to within 25% of the base-line. Intubating conditions were similar in both groups, but group 2 provided a significantly shorter apnoea time.

The effectiveness of prochlorperazine buccal as an anti-emetic for the prevention of post-operative nausea and vomiting in patients using intravenous patient-controlled analgesia with morphine following abdominal hysterectomy has been assessed in a randomized, double-blind, placebo-controlled study. Forty-nine female patients participated with 26 allocated to the prochlorperazine buccal group and the remainder to the placebo group. Each received either placebo or prochlorperazine buccal 6 mg, in each case by the buccal route, 1 h prior to anaesthesia with further doses at 6, 18, 30 and 42 h, respectively. Symptom scores in respect of nausea, pain and sedation, the number without nausea, the number without vomiting and the requirement for rescue anti-emetic therapy were noted for each 4-h period during the 48-h study. Morphine utilization and taste associated with the study material were recorded. Data for 21 patients in the placebo group and 25 patients in the prochlorperazine buccal group were available for analysis. Patients in the prochlorperazine buccal group showed significantly lower mean nausea scores at 4–8 h (placebo group: mean nausea score 0.95; prochlorperazine buccal group: mean nausea score 0.36; P<0.05) and at 16–20 h (placebo group: mean nausea score 1.24; prochlorperazine buccal group: mean nausea score 0.48; P <0.05). Furthermore, the prochlorperazine buccal group showed significantly more patients without nausea at 4–8 h (placebo group: 11 patients out of 21; prochlorperazine buccal group: 20 patients out of 25; P<0.05) and at 16–20 h (placebo group: nine patients out of 21; prochlorperazine buccal group: 18 patients out of 25; P<0.05). The prochlorperazine buccal group showed a significantly higher number of patients rating the taste as unsatisfactory (placebo group: two patients out of 21; prochlorperazine buccal group: nine patients out of 25; P<0.05). Intravenous droperidol is the current gold standard prophylactic anti-emetic in post-operative nausea and vomiting associated with intravenous patient controlled analgesia with morphine usage. This study has demonstrated a peri-operative prochlorperazine buccal regimen to be effective in post-operative nausea and vomiting prophylaxis in the use of intravenous patient controlled analgesia with morphine. Prochlorperazine buccal should be considered as an effective, inexpensive option for the prevention of post-operative nausea and vomiting in post-operative intravenous patient controlled analgesia with morphine administration.

Serious neurological complications of abdominal aortic vascular surgery are rare but devastating for all involved. When epidural blockade is part of the anaesthetic technique such compliscations may be attributed to needles, catheters or drugs. We present a patient who developed paraplegia following an elective abdominal aortic aneurysm repair. Continuous epidural blockade was part of the anaesthetic technique and postoperative analgesia. In this case the spinal cord damage was explained by ischaemia caused by the aortic surgery. This event has made us aware of a rare complication associated with abdominal aortic surgery and highlighted safety aspects of epidural anaesthesia in such patients.