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Biomedical subjects

S Alahuhta

Publications and source records attributed to S Alahuhta.

At least 19 recordsLinked to original sources
PubMed2006

Allocation of tasks between anesthesiologists and anesthesia nurses in Finland.

BACKGROUND: The shortage of anesthesiologists in Finland is worsening. A survey was carried out in 2003 among head anesthesiologists and head nurses to clarify current practice and the potentials for reorganizing tasks between anesthesiologists and anesthesia nurses. A national working group analyzed the results. METHODS: A questionnaire concerning doctor and nurse resources in anesthesiology, current allocation of tasks, and opinions on how these tasks could be reallocated was sent to 87 head anesthesiologists and 32 head nurses in 45 different hospitals. The answers from the doctors and nurses were compared. RESULTS: The response rate of doctors and nurses was 87% and 100%, respectively. In the enrolled hospitals there were 64 unoccupied positions for specialists in anesthesiology. The ratio of anesthesiologists to operation rooms (OR) they attended varied between 0.3 and 1.5. Doctors and nurses reported the allocation of tasks quite similarly. The great majority of respondents considered spinal, epidural, and interscalene brachial plexus blocks, and the induction of general anesthesia to be tasks that should be performed by an anesthesiologist. Very few respondents of either profession were willing to reallocate tasks so that nurses could deliver general anesthesia, including endotracheal intubation, even in low-risk patients. CONCLUSION: Nurses could be trained nationwide to perform procedures already performed by locally trained nurses in some hospitals. To cope with the shortage of anesthesiologists, other strategies must be adopted in addition to transferring part of their work load to nurses.

Anesthesia, General↗
PubMed2005

Ephedrine and phenylephrine for the treatment of maternal hypotension in a chronic sheep model of increased placental vascular resistance.

BACKGROUND: We hypothesized that ephedrine and phenylephrine are equal with respect to uterine and placental haemodynamics and fetal acid-base status after exposure to maternal hypoxaemia and hypotension in a chronic sheep model of increased placental vascular resistance (R(UA)). METHODS: At 114-135 days gestation, chronically instrumented fetal sheep underwent placental embolization leading to increased R(UA). Twenty-four hours after embolization, the ewes were anaesthetized and randomized to receive boluses of ephedrine (n=7) or phenylephrine (n=6) for epidural-induced hypotension after maternal hypoxaemia. Uterine (Q(UtA)) and placental (Q(UA)) volume blood flows and uterine vascular resistance (R(UtA)) and R(UA) were recorded. Uterine (PI(UtA)) and umbilical artery (PI(UA)) pulsatility indices were obtained by Doppler ultrasonography. Fetal arterial blood samples were analysed for acid-base values and lactate concentrations. RESULTS: During hypotension, Q(UtA), fetal pH, BE, and Po(2) decreased whereas R(UtA), PI(UtA), R(UA), and fetal lactate concentration increased. With ephedrine, Q(UtA), R(UtA), PI(UtA), R(UA), and fetal Po(2) returned to baseline. Fetal pH, BE, and lactate concentration did not change from hypotensive values. With phenylephrine, Q(UtA) remained lower (P=0.007) and R(UtA) (P=0.007), PI(UtA) (P=0.013), and R(UA) (P=0.050) higher than at baseline. Fetal Po(2) returned to baseline and fetal pH and BE did not change from hypotensive values. However, fetal lactate concentration increased further (mean difference 1.49, 95% confidence interval 0.72-2.26 mmol litre(-1); P=0.004). CONCLUSIONS: In a chronic sheep model of increased placental vascular resistance, compared with ephedrine administration, phenylephrine administration was associated with impaired uterine and placental haemodynamics and increased fetal lactate concentrations.

Anesthesia, Epidural↗
PubMed2005

Pharmacokinetics of 0.5% levobupivacaine following ilioinguinal-iliohypogastric nerve blockade in children.

BACKGROUND: Bupivacaine (2 mg kg(-1)) has been recommended for blockade of the ilioinguinal and iliohypogastric nerves in paediatric patients undergoing inguinal surgery. We determined the plasma concentrations of levobupivacaine following ilioinguinal-iliohypogastric block. METHODS: Twenty children scheduled for elective surgery for inguinal surgery received 2 mg kg(-1) of 0.5% levobupivacaine. Surgical anaesthesia was maintained with mask inhalation of oxygen, nitrous oxide and sevoflurane. Venous blood samples were drawn at regular intervals up to 2 h and plasma was separated. Total venous plasma concentrations were determined by gas chromatography. Bupivacaine concentrations from a study with a similar protocol were used as historical controls for comparison. RESULTS: The groups were similar with respect to age, weight and dosage of local anaesthetic. The initial distribution half-time (Talpha), the peak plasma concentration (Cmax) achieved, the time to the peak plasma concentration were similar (Tmax), and the mean areas under the concentration time curve (AUC) were similar between the two local anaesthetics. CONCLUSIONS: Levobupivacaine and bupivacaine are equally absorbed to similar maximum concentrations.

Anesthetics, Combined↗
PubMed2005

Comparison of remifentanil and nitrous oxide in labour analgesia.

BACKGROUND: We compared the efficacy and side-effects of remifentanil with those of nitrous oxide during the first stage of labour. METHODS: Twenty parturients participated in a randomized, double-blind, cross-over study. Intravenous remifentanil in 0.4 microg kg(-1) PCA doses with 1-min infusion and lock-out times and intermittent inhaled 50% nitrous oxide were compared during 20-min study periods with a 20-min wash-out sequence after each period. The parturients assessed the intensity of contraction pain (verbal numerical score 0-10), pain relief (score 0-4) and side-effects every 10 min. Noninvasive blood pressure, heart rate (HR), oxyhaemoglobin saturation (SaO2), end-tidal carbon dioxide, fractions of inhaled and exhaled oxygen and nitrous oxide and foetal heart rate (FHR) were recorded. Hypoxaemia and bradycardia were defined as SaO2<90% and HR<50, respectively. RESULTS: Fifteen parturients completed the study. There was no period effect or treatment-period interaction. The median decrease in pain score for remifentanil was 1.5 and that for nitrous oxide 0.5 (P=0.01). The parturients gave better pain relief scores with remifentanil than with nitrous oxide (median 2.5 vs. 0.5, respectively, P<0.001). Sedation was reported more often, and SaO2 was slightly lower during remifentanil administration. No episodes of hypoxaemia occurred. There was no difference in maternal blood pressure and HR or the incidence of abnormal FHR during remifentanil compared to nitrous oxide. Most parturients preferred remifentanil to nitrous oxide (14 vs. 1, P<0.001). CONCLUSIONS: This study suggests that IVPCA remifentanil provides better labour analgesia than intermittently inhaled nitrous oxide.

Administration, Inhalation↗
PubMed2004

Effects of ephedrine and phenylephrine on uterine and placental circulations and fetal outcome following fetal hypoxaemia and epidural-induced hypotension in a sheep model.

BACKGROUND: Recent studies support the use of alpha-agonists during regional anaesthesia in uncomplicated term pregnancies. We hypothesized that ephedrine and phenylephrine, administered for maternal hypotension following fetal hypoxaemia, are equal in respect of fetal outcome. METHODS: At 117-132 days gestation, chronically instrumented, anaesthetized and mechanically ventilated ewes were randomized to receive boluses of ephedrine (n=9) or phenylephrine (n=8) for maternal epidural-induced hypotension after a period of fetal hypoxaemia. Uterine (QUtA) and placental (QUA) volume blood flows were measured with perivascular transit-time ultrasonic flow probes, and uterine (RUtA) and placental (RUA) vascular resistances were computed from volume blood flows and maternal and fetal mean arterial pressures. Uterine (PIUtA) and umbilical artery (PIUA) pulsatility indices were obtained by Doppler ultrasonography. RESULTS: Ephedrine increased QUtA and decreased RUtA and PIUtA from a hypotensive to baseline level and had no significant effect on umbilical circulation. With phenylephrine, QUtA remained lower (P=0.011) and RUtA higher (P=0.043) than at baseline, although PIUtA decreased to baseline level. PIUA increased from baseline with phenylephrine (P=0.007), whereas QUA decreased (P=0.050). Maternal volume expansion with hydroxyethyl starch decreased RUtA significantly irrespective of the vasopressor used. There were no significant differences in fetal blood gas values or lactate concentrations between the ephedrine and phenylephrine groups. CONCLUSIONS: Despite the more favourable effects on uterine and placental circulations of ephedrine over phenylephrine, no significant differences in fetal acid-base status or lactate concentrations were observed.

Acid-Base Equilibrium↗
PubMed2004

Breast-feeding problems after epidural analgesia for labour: a retrospective cohort study of pain, obstetrical procedures and breast-feeding practices.

Various clinical practices have been found to be associated with breast-feeding problems. However, little is known about the effect of pain, obstetrical procedures and analgesia on breast-feeding behaviour. We designed a retrospective study with a questionnaire concerning pain, obstetrical procedures and breast-feeding practices mailed to 164 primiparae in Lapland. Altogether 99 mothers (60%) returned completed questionnaires that could be included in the analysis, which was carried out in two steps. Firstly, all accepted questionnaires were grouped according to the success or failure to breast-feed fully during the first 12 weeks of life. Secondly, an ad hoc cohort study was performed on the sub-sample of 64 mothers delivered vaginally. As many as 44% of the 99 mothers reported partial breast feeding or formula feeding during the first 12 weeks. Older age of the mother, use of epidural analgesia and the problem of "not having enough milk" were associated with the failure to breast-feed fully. Caesarean section, other methods of labour analgesia and other breast-feeding problems were not associated with partial breast feeding or formula feeding. In the sub-sample, 67% of the mothers who had laboured with epidural analgesia and 29% of the mothers who laboured without epidural analgesia reported partial breast feeding or formula feeding (P = 0.003). The problem of "not having enough milk" was more often reported by those who had had epidural analgesia. Further studies conducted prospectively are needed to establish whether a causal relationship exists between epidural analgesia and breast-feeding problems.

Adult↗
PubMed2004

Evoked EEG patterns during burst suppression with propofol.

BACKGROUND: During EEG suppression with isoflurane or sevoflurane anaesthesia, median nerve stimulation causes cortical responses of two kinds: an N20 wave with a latency of 20 ms and an EEG burst with a latency of 200 ms. We tested the possibility that median nerve stimulation during EEG suppression with propofol would cause an EEG response that was consistent enough to be of use for neuromonitoring. METHODS: Eight patients were anaesthetized with propofol to allow burst suppression. Electrical stimulation of the median nerve was applied during general anaesthesia and the EEG was measured. RESULTS: The EEG response to a painful stimulus had four successive components: (i) N20 and P22 potentials, reflecting activation of fast somatosensory pathways; (ii) a high-amplitude negative wave, possibly reflecting activation of the somatosensory cortex SII bilaterally; (iii) a burst (i.e. a negative slow wave with superimposed 10 Hz activity, probably reflecting an arousal mechanism); and (iv) a 13-15 Hz spindle, probably originating from the thalamus, similar to sleep spindles. These could be seen separately and in different combinations. Bursts and spindles during burst suppression were also seen without stimulation. In deepening propofol anaesthesia, spindles were seen in the continuous EEG before burst suppression was achieved. In deep anaesthesia, spindles were seen when bursts had ceased, and painful stimuli evoked sharp waves without subsequent bursts. CONCLUSION: In addition to SSEP (somatosensory evoked potentials), three different evoked responses are noted that could be useful for clinical monitoring.

Adult↗
PubMed2002

Oral ondansetron, tropisetron or metoclopramide to prevent postoperative nausea and vomiting: a comparison in high-risk patients undergoing thyroid or parathyroid surgery.

BACKGROUND: Oral antiemetic prophylaxis may be a practical alternative to intravenous administration. Intravenous ondansetron and tropisetron prevent postoperative nausea and vomiting (PONV) at least as efficiently as traditional antiemetics, droperidol and metoclopramide. We tested the hypothesis that the incidence of PONV after oral ondansetron or tropisetron prophylaxis is lower compared with metoclopramide among high-risk patients. METHODS: In a prospective, double-blind study we studied 179 high-risk patients who received either ondansetron 16 mg, tropisetron 5 mg, or metoclopramide 10 mg orally 1 h before the operation. A standard general anesthetic technique and postoperative analgesia were used. The incidence of PONV and the need for rescue antiemetic medication was recorded for 24 h. RESULTS: In the postanesthesia care unit, the incidence of PONV was lower after premedication with tropisetron compared with ondansetron and metoclopramide (15%, 32% and 39%, respectively). The incidence of PONV during 0-24 h was the same in each group (68%, 58% and 75% in the ondansetron, tropisetron and metoclopramide group, respectively), but the incidence of vomiting was significantly lower after ondansetron (34%) and tropisetron (22%) prophylaxis compared with metoclopramide (53%). The need for additional antiemetics was significantly lower after tropisetron prophylaxis compared with metoclopramide. Patient satisfaction was significantly higher after tropisetron than after metoclopramide. CONCLUSIONS: In the initial period, the incidence of PONV was lower after premedication with oral tropisetron than after ondansetron or metoclopramide. Considering the entire 24-h postoperative period, the incidence of PONV was the same after all three premedications, but the incidence of vomiting was lower after oral ondansetron and tropisetron than after metoclopramide.

Adult↗
PubMed2002

Mortality among Finnish anesthesiologists from 1984-2000.

BACKGROUND: Previous studies have suggested increased mortality among anesthesiologists. We report age-standardized mortality rates and causes of death among Finnish anesthesiologists. METHODS: Data covering the deaths of all medical specialists during 1984-2000 were obtained and analyzed. There were 799 deaths, of which 18 involved anesthesiologists. The causes of deaths of these anesthesiologists were obtained from the database of Statistics Finland. RESULTS: The age-standardized mortality rate (SR) for the male anesthesiologists was 33.9 years (per 1000), and that for the other male specialists was 84.6 years. The SR for the female anesthesiologists was 45.4 years, and that for the other female specialists was 77.3 years. The mean age at death among the anesthesiologists was 63.0 years (SD 11.0), while the mean age at death among the other specialists was 68.6 years (SD 14.7). The age structures of the anesthesiologists and other specialists were different, with the anesthesiologists being younger. CONCLUSION: The different age distributions of the anesthesiologists and other specialists caused the difference in age at death. The SR values for the anesthesiologists are clearly lower than those for other specialists. Thus, the present findings do not show increased mortality among Finnish anesthesiologists.

Adult↗
PubMed2002

Pharmacokinetics of 0.75% ropivacaine and 0.5% bupivacaine after ilioinguinal-iliohypogastric nerve block in children.

BACKGROUND: Blockade of the ilioinguinal and iliohypogastric nerves is a useful procedure in paediatric patients undergoing inguinal surgery. Bupivacaine 2 mg kg-1 has been recommended for this block. We compared the plasma concentrations of ropivacaine and bupivacaine following an ilioinguinal-iliohypogastric block. METHODS: Forty children scheduled for elective inguinal surgery were randomized to receive 2 mg kg-1 of either 0.75% ropivacaine or 0.5% bupivacaine. Surgical anaesthesia was maintained with mask inhalation of oxygen, nitrous oxide and sevoflurane. Venous blood samples were drawn at regular intervals for up to 2 h and plasma was separated. Total venous plasma concentrations were determined by gas chromatography. RESULTS: The groups were similar with respect to age, weight and dose of local anaesthetic. The peak plasma concentration achieved was significantly higher in the bupivacaine group compared with the ropivacaine group (2.2 vs 1.2 micrograms ml-1, P = 0.025). The time to peak plasma concentration was significantly shorter in the bupivacaine group (24 vs 35 min, P = 0.024). The initial distribution half time of bupivacaine was significantly shorter (3.6 vs 6.5 min, P = 0.020) compared with that of ropivacaine. CONCLUSIONS: Bupivacaine is more rapidly absorbed from the injection site and leads to higher plasma concentrations than ropivacaine.

Adolescent↗
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↗