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Biomedical subjects

S Alahuhta

Publications and source records attributed to S Alahuhta.

At least 19 recordsLinked to original sources
PubMed2001

Ropivacaine 1 mg x ml(-1) does not decrease the need for epidural fentanyl after hip replacement surgery.

BACKGROUND: Ropivacaine is a new long-acting local anesthetic. Laboratory trials have demonstrated a synergistic analgesic effect between intrathecal opioids and local anesthetics. We tested the hypothesis that addition of ropivacaine 1 mg x ml(-1) to epidural fentanyl (10 microg x ml(-1)) postoperatively decreases the need for fentanyl, improves the quality of analgesia and decreases the side-effects of fentanyl. METHODS: Forty patients were enrolled in this double-blind, randomized study to receive either fentanyl 10 microg x ml(-1) (group F) alone or fentanyl combined with ropivacaine 1 mg x ml(-1) (group R) for 20 h as an epidural infusion at TH12-L1 or L1-L2 for analgesia after hip replacement surgery. The patients were free to use a patient-controlled epidural analgesia device, which was programmed to infuse 3 ml of the study medication hourly and to allow a 3-ml bolus when needed (maximal hourly dose of fentanyl was 150 microg). The consumption of medication, visual pain scores at rest and on movement, hemodynamic and respiratory parameters, motor and sensory block, nausea, pruritus and sedation were recorded. RESULTS: There were no significant differences between the groups in the total mean fentanyl consumption (1.10+/-0.18 mg in group F, 1.08+/-0.31 mg in group R, 95% CI: -0.14 to 0.19, P = 0.774). The pain scores were similar at rest (median scores < or = 1) and on movement (median scores < or = 3). The adverse effects were similar and of a minor nature, consisting mostly of pruritus and nausea. CONCLUSION: Addition of ropivacaine 1 mg x ml(-1) to epidural fentanyl 10 microg x ml(-1) did not significantly decrease the requirement for fentanyl administered for pain relief after hip replacement surgery.

Adult↗
PubMed2001

Inhaled nitric oxide effectively decreases right heart afterload following right heart infarct in pigs.

OBJECTIVE: To test the hypothesis that nitric oxide is beneficial in acute right heart failure after right ventricle infarct. Right ventricle infarct results in a decrease in right heart function with a subsequent reduction in ejection fraction and cardiac index. The pulmonary circulation is compromised as the right ventricle weakens, and the resulting stasis and further weakening of the ventricle present clinically as an increase in right heart afterload. Pulmonary vasodilation should ease these hemodynamic symptoms of right heart infarct. DESIGN: Ten 3-4-month-old pigs were chosen as experimental animals. All animals were cannulated, a sternotomy was performed and branches of the right main coronary were ligated to cause infarct of the right ventricle. After a 4-h stabilization period, all animals received fluid preload with a dextrose-based solution after which control hemodynamic measurements were recorded. Treatment with inhaled nitric oxide was begun at progressive concentrations and hemodynamic measurements recorded at 30-min intervals. RESULTS: Nitric oxide treatment significantly reduced right heart afterload, which was also apparent as a reduction in left heart preload. A significant deterioration was observed in cardiac output as well as in left and right ventricle stroke work indices. CONCLUSION: The use of nitric oxide in this model of right heart infarct in previously healthy young swine effected a decrease in both right heart afterload and left heart preload, with an overall deterioration in global hemodynamics.

Administration, Inhalation↗
PubMed2001

The haemodynamic effects of losartan after right ventricle infarct in young pigs.

The effect of an intravenous bolus injection of the type 1 angiotensin II receptor antagonist, losartan on haemodynamics after right heart infarct was studied in an experimental setting. Right heart infarct was induced in twelve young swine and losartan was given in a bolus intravenous dose one hr later to five animals, while seven animals served as controls. Haemodynamics were then followed for one hr at 15 min intervals. Losartan was subsequently shown to decrease central venous pressure and wedge pressure, while cardiac output, left ventricle stroke work and stroke volume all showed improvement. Compared to the control animals, pulmonary vascular resistance, systemic vascular resistance and systemic pressures were unaffected by the drug, as was heart rate. The use of losartan shortly after right heart infarct reduced both right and left heart preload as well as inducing an improvement in cardiac performance. At the same time, systemic pressures and heart rate were maintained. We conclude that an inhibition of angiotensin II action may be a benefit in the treatment of right heart failure symptoms during the first hours after right heart infarct.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed2000

Two instances of central nervous system toxicity in the same patient following repeated ropivacaine-induced brachial plexus block.

We describe two instances of central nervous system (CNS) toxicity in the same patient following repeated brachial plexus blocks induced by high doses of ropivacaine (6 mg x kg(-1) and 4.5 mg x kg(-1), respectively). Although very high total and free plasma concentrations of ropivacaine were found up to 98 min after induction of the blocks, no signs of cardiovascular toxicity apart from hypertension and sinus tachycardia were observed. The measured plasma concentrations are the highest so far reported in the literature. We conclude that this case demonstrates the high cardiovascular safety level of ropivacaine. These high doses, however, resulted in severe toxic CNS symptoms. Therefore, it is stressed that the dose in relation to the weight of the patient must be calculated when administering a large volume of local anesthetic.

Acute Disease↗
PubMed2000

Pharmacokinetics of 0.2% ropivacaine and 0.2% bupivacaine following caudal blocks in children.

BACKGROUND: Ropivacaine is the first S-enantiomer aminoamide local anaesthetic in clinical use, and has been found to be less toxic than bupivacaine. Caudal ropivacine has been shown to cause less motor blockade and longer duration of analgesia in the postoperative period than bupivacaine in children. Plasma levels of ropivacaine and bupivacaine have not been previously compared in children. This study was undertaken to compare the total venous plasma concentrations of similar doses of ropivacaine and bupivacaine following caudal administration. METHODS: Blood samples were obtained to determine the total venous plasma levels of the used local anaesthetic in 30 children, aged 2.3-8.7 years, ASA I, given 1 ml x kg of either 0.2% ropivacaine or 0.2% bupivacaine in a prospective, randomised manner. RESULTS: There were no differences in the individual peak plasma concentrations achieved. Time to the measured peak plasma concentration was significantly shorter in the bupivacaine group. The plasma concentrations of bupivacaine were significantly lower than for ropivacaine at 60, 90 and 120 min after the block. CONCLUSION: Absorption and tissue distribution of ropivacaine is slower than for bupivacaine following caudal administration in children.

Amides↗
PubMed2000

The effect of aminophylline on right heart function in young pigs after ligation of the right coronary artery.

An experimental model of right heart failure was developed to determine the effects of fluid loading and aminophylline on right heart function. We hypothesised that aminophylline would specifically improve right heart function through a decrease in pulmonary vascular resistance and, possibly, an increase in cardiac contractility. Right heart infarct was induced in ten experimental pigs and seven control pigs by ligating branches of the right coronary artery. The effect of fluid loading with a colloid solution and subsequent bolus doses of aminophylline on haemodynamics was observed. Fluid loading improved haemodynamics as expected. Aminophylline transiently improved cardiac index and pulmonary vascular resistance, but simultaneously caused an increase in heart rate and a decrease in stroke volume. Although aminophylline may reduce right heart afterload, it did not improve overall cardiac function in this experimental model of right heart infarction.

Aminophylline↗
PubMed2000

Improving the quality of postoperative pain relief.

A review of the literature shows a constant need to improve the quality of postoperative pain management. The objective of this study was to decrease the intensity and variation of postoperative pain by developing a nurse-based pain service on the ward. An acute pain nurse was appointed and an educational programme with detailed algorithms was started. Regular pain intensity measurements were implemented. Postoperative pain intensity, treatments and side-effects were assessed both before and after the introduction of the new system in 400 patients divided into two consecutive groups of equal size. The number of patients with inadequately treated pain (actual pain > 3/10) dropped by 64% after major gynaecological surgery (25 vs 9%, 95% CI for differences 7-24%; p<0.001 for pain scores). On an average, inadequate pain relief (retrospective average pain > 3/10) on the first postoperative day was more frequent on the ward before than after the reform (47 vs. 21%; 95% CI for differences 15-35%; p<0.001 for pain scores). The incidence of side-effects was similar in both groups (p> 0.05). The intensity and variation of postoperative pain on the ward decreased by developing a nurse-based pain service with an acute pain nurse, an educational programme and regular pain intensity measurements.

Activities of Daily Living↗
PubMed2000

The hemodynamic effects of adenosine infusion after experimental right heart infarct in young swine.

The use of a vasodilator selective to the pulmonary circulation may be beneficial in cases with right-ventricle failure, as it will decrease right-heart afterload without concurrent systemic hypotension. Adenosine has recently been advocated as such a drug, although its clinical efficacy in this respect is still in question. We therefore devised an experimental protocol of right-heart infarct to test the efficacy of adenosine in alleviating symptoms of right-heart failure. Right-heart infarct was induced experimentally in 17 young pigs. After hemodynamics had stabilized, preload was optimized with a dextrose-based colloid solution. A continuous infusion of adenosine was then begun at doses of 25, 50, 75, and 100 microg/kg/min in a study group of 10 animals, while the remaining seven were monitored as controls. Hemodynamic parameters were followed throughout the study, with particular attention paid to pulmonary and systemic vascular resistance indices (PVRI and SVRI), right ventricle ejection fraction (REF), cardiac index (CI), and heart rate (HR). Cardiac index (CI) showed a tendency to increase during the adenosine infusion, as did REF and stroke index (SI), whereas PVRI and mean pulmonary pressure (MPAP) were decreased. There was a marked decrease in SVRI as a result of the adenosine, as there was in mean arterial pressure at the higher infusion rates. HR remained unchanged by the infusion. Discontinuation of the drug resulted in a rapid increase in MAP, SVRI, MPAP, HR, left ventricle stroke work index (LVSWI), and PVRI and in a modest decrease in CI. The continuous infusion of adenosine appears to cause an effective arterial vasodilation, with a consequent unloading of right-heart afterload. Its use may be beneficial in the treatment of increased pulmonary vascular resistance after right-heart failure.

Adenosine↗
PubMed1999

Tibial nerve somatosensory evoked potentials during EEG suppression in sevoflurane anaesthesia.

OBJECTIVES AND METHODS: Cortical tibial nerve somatosensory evoked potentials (TSEPs) were recorded from 10 subjects in sevoflurane anaesthesia in order to study TSEP during EEG suppression. RESULTS: With a stimulation frequency less than one per second the major component was a positive wave which had maximal amplitude parietally ipsilaterally to stimulus and mean latency of 46.1 ms. It probably corresponds to the P40 wave. It was preceded by a widespread smaller positive wave, which corresponds to the subcortical P30 wave. In two patients a high amplitude negative wave, a couple of milliseconds before the positive wave, and maximal parietally contralateral to stimulus, was seen. All later waves were absent. CONCLUSION: The results are in agreement with our previous results from median nerve SEPs showing that the first cortical response from primary somatosensory cortex is enhanced, and later waves are suppressed. Hence, recording TSEPs during EEG suppression provides a way to record the activity of the primary somatosensory cortex accurately and rapidly due to the very good signal to noise ratio, so that even single responses to stimuli can be seen without averaging. Our results suggest that new cortical generators, which are not recordable awake, may be discovered in some patients.

Adult↗
PubMed1999

Clinical efficacy and pharmacokinetics of 1% ropivacaine and 0.75% bupivacaine in peribulbar anaesthesia for cataract surgery.

Peribulbar anaesthesia with 1% ropivacaine and 0.75% bupivacaine, both with hyaluronidase, was assessed in a prospective, randomised, double-blind study of 100 patients undergoing cataract surgery. Pharmacokinetic data were obtained from 22 subjects. Akinesia of the globe developed slightly more rapidly in the ropivacaine group, but this difference was only statistically significant at 2 min after injection of the local anaesthetic. Lid akinesia was significantly more complete in the ropivacaine group. There were no differences between the groups with respect to peri-operative analgesia or duration of akinesia. The dose-adjusted maximum concentration of ropivacaine was approximately twice that of bupivacaine with significantly higher values of the area under the concentration-time curves. No drug-related adverse effects were observed. We conclude that there are no clinically significant differences in the quality of the sensory and motor block between 1% ropivacaine and 0.75% bupivacaine when used for peribulbar anaesthesia.

Aged↗
PubMed1997

A survey of postoperative nausea and vomiting.

A prospective interview-based survey on the incidence of postoperative nausea and vomiting in 1107 in-patients aged 4-86 years was conducted during a 3-month period. Nausea, emetic episodes and the need for anti-emetic medication were recorded for 24 h postoperatively. In the recovery room, the incidence of nausea and vomiting was 18% and 5%, respectively. Over the whole 24-h period, these figures were 52% and 25%, respectively; severe nausea was experienced by 8%. The highest incidence of emetic sequelae was observed in gynaecological patients; 52% of the 822 patients who received general anaesthesia and 38% of the 285 patients who received regional anaesthesia reported nausea. The most important predictive factors associated with an increased risk for nausea and vomiting were female gender, a previous history of postoperative sickness, a longer duration of surgery, nonsmoking and a history of motion sickness. Based on these five items, a simple score predicting the risk of nausea and vomiting was constructed with a moderately good discriminating power.

Adolescent↗
PubMed1997

The anti-emetic efficacy of a combination of ondansetron and droperidol.

The anti-emetic efficacy of a combination of ondansetron 8 mg with either droperidol 0.75 mg or 1.25 mg given prophylactically was studied in a randomised blinded trial of 94 female inpatients with a previous history of postoperative nausea and vomiting and scheduled to have laparoscopic surgery. A standardised general anaesthetic technique was used for all patients. The mean estimated risk of postoperative sickness according to predictive patient characteristics was 65% for both treatment groups. During the 24 h study period, the proportion of patients with nausea was similar (35%) in both groups, and vomiting occurred in 16% and 14% of the patients in the droperidol 0.75 mg and 1.25 mg groups, respectively. No serious adverse events were observed. Ondansetron in combination with droperidol 0.75 mg resulted in less drowsiness than in combination with 1.25 mg (p = 0.03). In conclusion, a prophylactic combination treatment of ondansetron 8 mg with a small dose of droperidol was clinically effective and well tolerated for the prevention of postoperative nausea and vomiting after laparoscopic surgery in patients with a high probability of nausea and vomiting.

Adult↗
PubMed1997

Comparison of ondansetron and droperidol in the prevention of postoperative nausea and vomiting after laparoscopic surgery in women. A randomised, double-blind, placebo-controlled trial.

BACKGROUND: Women undergoing laparoscopic surgery are susceptible to postoperative nausea and vomiting (PONV). Ondansetron and droperidol are useful antiemetics. This study was designed to ascertain primarily the relative difference in efficacy of ondansetron and droperidol and secondarily between these drugs and placebo in the prevention of PONV after laparoscopic surgery. METHODS: The prophylactic antiemetic efficacy of ondansetron and droperidol was compared in a prospective, randomised, double-blind, placebo-controlled trial of 439 female inpatients scheduled for laparoscopic surgery. During induction of standardised general anaesthesia the patients received intravenously either ondansetron 8 mg (n=195), droperidol 1.25 mg (n=193) or placebo (n=51). The occurrence of nausea, vomiting, side-effects and the need for rescue antiemetic medication were recorded for 24 h postoperatively. RESULTS: The proportion of patients with nausea was 48%, 50% and 67% in the ondansetron, droperidol and placebo groups, respectively; with a significant difference when both ondansetron (P=0.02) and droperidol (P=0.04) were compared with placebo. Vomiting occurred in 18%, 26% and 37% of the patients in the three groups, respectively (P=0.05 between ondansetron and droperidol, P=0.004 between ondansetron and placebo, P=0.16 between droperidol and placebo). The proportion of patients given rescue medication was 34%, 28% and 49%, respectively (P=0.23 for ondansetron and droperidol, P=0.07 for ondansetron and placebo, P=0.007 for droperidol and placebo). During early recovery the patients treated with ondansetron were significantly more alert than after droperidol. Serious side-effects were not observed. Headache was significantly more common after ondansetron than after droperidol treatment. CONCLUSIONS: The efficacy of prophylactic ondansetron and droperidol in reducing postoperative nausea associated with laparoscopic surgery in female inpatients was similar, but ondansetron appeared to be slightly more efficient than droperidol in preventing vomiting. Ondansetron and droperidol were both significantly better than placebo in the prophylaxis of PONV.

Adolescent↗
PubMed1996

Maternal and uteroplacental haemodynamic state in pre-eclamptic patients during spinal anaesthesia for Caesarean section.

We have studied the effects of crystalloid (Ringer's acetate 1 litre) preloading and subsequent spinal anaesthesia in 12 pre-eclamptic parturient patients undergoing elective Caesarean section. Maternal placental uterine artery circulation was measured using a pulsed colour Doppler technique with simultaneous measurement of maternal haemodynamic state. Despite preloading, mean maternal systolic arterial pressure (SAP) decreased significantly and marked maternal hypotension (SAP < 80% of baseline value) was recorded in two patients after induction of spinal anaesthesia. Mean central venous pressure increased significantly after preload, but decreased to baseline shortly after induction of spinal anaesthesia. Mean pulsatility index (PI) in the uterine artery did not change during preload or spinal block. In one patient, uterine artery PI increased significantly when SAP decreased to 71% of the baseline value, 14 min after induction of spinal anaesthesia. These results suggest that preload with crystalloid solution does not prevent maternal hypotension in pre-eclamptic patients, and that changes in uterine artery velocity waveforms were minor when SAP was 80% or more of baseline during spinal anaesthesia. These changes did not appear to have any major effect on the clinical condition of the neonate, as assessed by Apgar score and umbilical artery pH values.

Adult↗
PubMed1996

Single bolus compared with a fractionated dose injection technique of bupivacaine for extradural Caesarean section: effect on uteroplacental and fetal haemodynamic state.

We studied 26 healthy parturients undergoing elective Caesarean section, allocated randomly to receive extradural block with 0.5% plain bupivacaine in a double-blind manner in either a single bolus or fractionated doses. After a 3-ml test dose, an additional 20 ml of bupivacaine were given over a 5-min period in the single bolus group (n = 13) and over a 25-min period in the fractionated dose group (n = 13). We studied the effects of bupivacaine on blood flow velocities in the maternal placental and non-placental uterine and fetal umbilical arteries before and four times during establishment of extradural block using a pulsed colour Doppler technique. Median sensory block reached T3 in the single-dose group compared with T4 in the fractionated-dose group. Two subjects in each group required i.v. ephedrine to correct transient hypotension (systolic arterial pressure < 90 mm Hg). Blood flow velocity waveform indices of the uterine and umbilical arteries did not differ significantly within or between groups during the study. There was no significant difference in neonatal outcome, as assessed by Apgar scores and umbilical artery pH values. In conclusion, we observed no deterioration in uteroplacental circulation after administration of a single bolus dose of bupivacaine.

Adult↗