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Biomedical subjects

B Chraemmer-Jørgensen

Publications and source records attributed to B Chraemmer-Jørgensen.

At least 19 recordsLinked to original sources
PubMed1994

Effect of 1 or 2 MAC isoflurane with or without ketanserin on cerebral blood flow autoregulation in man.

We have studied the effect of 1 or 2 MAC isoflurane with or without ketanserin on cerebral blood flow (CBF), cerebral oxygen metabolism (CMRO2) and CBF autoregulation in 20 adult patients undergoing lumbar disc surgery. Ten patients received ketanserin and 10 isotonic saline. CBF measurements were started after 1 h of infusion of saline or ketanserin. The patients were anaesthetized with thiopentone 5 mg kg-1 followed by isoflurane. During 1 MAC of isoflurane, baseline values were recorded and then CBF autoregulation was examined (mean arterial pressure increased by about 30% with angiotensin). The sequence was repeated with 2 MAC of isoflurane. CBF was measured by the i.v. xenon-133 technique. CMRO2 was calculated as the product of CBF and the cerebral arterio-venous oxygen content difference. Ketanserin had no effect on CBF, CMRO2 or CBF autoregulation during isoflurane anaesthesia, therefore all patients were pooled for evaluation of the effect of isoflurane. Increasing isoflurane anaesthesia from 1 to 2 MAC increased mean CBF from 41 to 49 ml/100 g min-1 (P < 0.01) and decreased mean CMRO2 from 1.5 to 1.1 ml/100 g min-1 (P < 0.001) and thus abolished the coupling between flow and metabolism. The CBF autoregulation test indicated that autoregulation was disrupted at 2 MAC, but not during 1 MAC isoflurane anaesthesia.

Adult↗
PubMed1992

Effect of ketanserin on global cerebral blood flow and cerebral oxygen metabolism during midazolam-fentanyl or isoflurane anaesthesia.

We have studied the effect of ketanserin on cerebral blood flow (CBF), cerebral oxygen metabolism (CMRO2) and cerebrovascular carbon dioxide reactivity in 19 adult patients undergoing lumbar disc operation--10 during midazolam-fentanyl anaesthesia (group A) and nine during isoflurane anaesthesia (group B). Measurements were made in each patient whilst awake, during anaesthesia, during anaesthesia with ketanserin and during anaesthesia with ketanserin and hyperventilation. CBF was measured by the i.v. xenon-133 technique. CMRO2 was calculated as the product of CBF and the cerebral arterio-venous oxygen content difference. In the awake state, CBF was 52 and 51 ml/100 g min-1 and CMRO2 3.8 and 3.5 ml/100 g min-1 in groups A and B, respectively. After induction of anaesthesia, CBF decreased 37% in group A and 22% in group B (P < 0.05); CMRO2 decreased 26% in group A and 51% in group B (P < 0.05). Adding ketanserin did not change CBF or CMRO2 in either group. The carbon dioxide reactivity of the cerebral vessels during anaesthesia with ketanserin was 15.4% kPa-1 in group A and 24% kPa-1 in group B. We concluded that ketanserin, in a clinically recommended dose, administered during midazolam-fentanyl or isoflurane anaesthesia had no effect on global CBF, CMRO2 or the relationship between the two factors. Cerebrovascular carbon dioxide reactivity was preserved.

Adult↗
PubMed1992

Catecholamine response to laryngoscopy and intubation. The influence of three different drug combinations commonly used for induction of anaesthesia.

The haemodynamic response and changes in plasma catecholamine concentrations associated with laryngoscopy and tracheal intubation were compared during anaesthesia employing three strictly standardised techniques with commonly used drug combinations. Thirty-six patients were investigated consecutively resulting in 12 patients in each of three study groups. Anaesthesia was induced with thiopentone 5 mg.kg-1 (group 1), fentanyl 6 micrograms.kg-1 with thiopentone 5 mg.kg-1 (group 2), or midazolam 0.2 mg.kg-1 with fentanyl 6 micrograms.kg-1 (group 3). Undesirable changes in haemodynamic effects and an elevation of plasma catecholamine concentrations during laryngoscopy and intubation occurred in group 1. Heart rate and mean arterial pressure increased significantly (34% and 23% respectively). Noradrenaline concentration increased by a maximum of 147%. The addition of fentanyl (groups 2 and 3) attenuated the adverse haemodynamic response and elevation of plasma catecholamine concentrations; heart rate and mean arterial pressure did not differ from pre-intubation values and plasma catecholamine concentrations decreased steadily. Substitution of thiopentone by midazolam in combination with fentanyl abolished the adverse haemodynamic response and modified the increase in plasma catecholamine concentrations. 'High-dose' opioid anaesthesia is not necessary to produce optimal conditions during laryngoscopy and intubation.

Adolescent↗
PubMed1992

Does alfentanil preserve left ventricular pump function during rapid sequence induction of anaesthesia?

A double-blind, randomised trial was conducted in 24 patients without cardiopulmonary disorders (20-43 years), to assess the effect of an intravenous bolus of alfentanil on the circulatory and catecholamine responses to rapid sequence induction of general anaesthesia. Induction included injection of thiopentone 5 mg/kg and suxamethonium 1.5 mg/kg in rapid succession, followed by laryngoscopy and intubation. Half of the patients received alfentanil 100 micrograms/kg immediately before thiopentone. The other half received saline. Blood pressure, heart rate, and plasma catecholamine concentrations were measured repeatedly, together with left ventricular ejection fraction assessed by radionuclide angiocardiography. The responses following laryngoscopy and intubation were completely different in the saline vs. the alfentanil group: rate pressure product +76% vs. -32%, mean arterial blood pressure +46% vs. -25%, heart +46% vs. no change, noradrenaline +117% vs. -25%, adrenaline +50% vs. -53%, and left ventricular ejection fraction -32% vs. no change. In conclusion, during rapid sequence induction of anaesthesia with thiopentone and suxamethonium, an intravenous bolus of alfentanil 100 micrograms/kg 1 min before laryngoscopy and intubation completely prevents hypertension, tachycardia, decrease in left ventricular ejection fraction, and activation of plasma catecholamines, though at the expense of moderate hypotension.

Adult↗
PubMed1992

Intra-articular bupivacaine plus adrenaline for arthroscopic surgery of the knee.

The purpose of the study was to evaluate three different doses of intra-articular bupivacaine plus adrenaline in relation to per- and postoperative pain relief following arthroscopy. Sixty patients were allocated to three groups of 20 patients each scheduled for arthroscopy. They were randomized prospectively to receive bupivacaine plus adrenaline 25 mg + 50 micrograms, 50 mg + 100 micrograms, 75 mg + 150 micrograms, respectively, diluted to a volume of 30 ml. Four patients were excluded because the operation could not be carried out under intra-articular analgesia, 18 patients had a diagnostic arthroscopy and 38 patients had different arthroscopic operations performed. The number of patients scoring pain in the knee as moderate or severe was less in Group 3 than in the other two groups, i.e. the highest dose had a better pain relief. No adverse effects were registered. With respect to per- or postoperative administration of analgesics, postoperative pain occurrence, and the surgeon's acceptance of the method, there were no statistically significant differences. Ninety-two percent of the patients would prefer intraarticular analgesia if they should need to have another arthroscopy performed.

Adolescent↗
PubMed1991

Left-ventricular performance, volumes, and catecholamine responses during anaesthesia induction--monitoring by combined radionuclide cardiography and right heart catheterization.

Sequential radionuclide imaging and continuous recording of arterial and right heart pressures were carried out during anaesthesia with midazolam 0.2 mg kg-1, pancuronium 0.15 mg kg-1 and fentanyl 10 micrograms kg-1 in eight patients with normal cardiopulmonary status scheduled for craniotomy. The aim was to examine how a stress-free anaesthetic induction tailored to protect against the hypertension and tachycardia provoked by laryngoscopy and intubation influenced left-ventricular performance, left-ventricular loading conditions and plasma catecholamine concentrations. During the 20-min study period no significant changes were observed in heart rate, left-ventricular ejection fraction, ratio of peak systolic pressure to left-ventricular end-systolic volume, pulmonary capillary wedge pressure, left-ventricular end-systolic volume, cardiac output, dopamine and noradrenaline concentrations. Except for a minor increase in mean arterial pressure after laryngoscopy and intubation, mean arterial pressure decreased 24%, left-ventricular end-diastolic volume decreased 15%, and left-ventricular stroke volume decreased 21%. Central venous pressure increased by 75% but there was no parallel increase in pulmonary wedge pressure, which in turn did not reflect the alterations in ventricular end-diastolic volume. Plasma adrenaline concentrations decreased significantly (66%). The chosen induction regimen preserved global left-ventricular pump function during laryngoscopy and intubation without any activation of the sympathetic nervous system. Central venous and pulmonary wedge pressures were unreliable in the assessment of ventricular preload during induction of general anaesthesia.

Adult↗
PubMed1988

Buprenorphine antagonism of ventilatory depression following fentanyl anaesthesia.

In order to compare the effect of buprenorphine and naloxone on respiratory depression after fentanyl anaesthesia (25 micrograms/kg), 32 women scheduled for elective abdominal hysterectomy participated in a double-blind randomized investigation. At termination of anaesthesia, after antagonizing residual neuromuscular blockade, 20 normocapnic patients with a respiratory rate of 4 breaths/min or less entered the study, receiving either buprenorphine (0.6 mg in 20 ml NaCl) or naloxone (0.4 mg in 20 ml NaCl) 2 ml/min until 20 ml was given or until the respiratory rate exceeded 8 breaths/min. Respiratory rate, PaCO2, sedation score, and pain intensity were evaluated during a 3-h study period. Fifteen min after beginning the treatment, all the patients in both groups had their ventilatory depression antagonized. There were no statistically significant differences in respiratory rates between groups except at 15 min. On no occasion did either PaCO2 or a sedation score differ statistically significantly between the groups. At 15 min all patients in the buprenorphine group had no or mild pain, compared to the patients in the naloxone group, of whom 50% had moderate to severe pain (P less than 0.05). It seems as if buprenorphine is as effective as naloxone in antagonizing respiratory rate depression following fentanyl anaesthesia.

Adult↗
PubMed1988

The reliability of measuring left ventricular ejection fraction by radionuclide cardiography: evaluation by the method of variance components.

A statistical model based on the method of variance components was applied to obtain confidence statements for single and repeat determinations of left ventricular ejection fraction by radionuclide techniques. With this approach variance caused by individual factors in the measurement procedure is estimated to allow calculation of confidence intervals based on single measurements and the detection limits for changes. Six study groups made up of a total of 143 subjects were examined by both multigated equilibrium and first pass imaging. Under favourable conditions (with an updated gamma camera and experienced observer) the 95% confidence interval with a single measurement of left ventricular ejection fraction by equilibrium imaging was +/- 3 ejection fraction units, compared with +/- 6 units with the first pass technique (one ejection fraction unit = 1/100 of the possible values from 0.00 to 1.00). The minimal significant changes (at the 5% level) in measured equilibrium left ventricular ejection fraction at intervals of 15 min, 3 days, 1, 3, and 4 weeks were +/- 4, +/- 4, +/- 5, +/- 5, and +/- 6 units, respectively. The corresponding minimal detectable changes in a subject's "true" left ventricular ejection fraction for the same intervals were +/- 7, +/- 7, +/- 10, +/- 10, and +/- 12 units respectively. With first pass imaging, only average values for the variation at repeat determination could be calculated. The minimal significant change in measured first pass left ventricular ejection fraction was +/- 7 units, and the minimal detectable change in "true" left ventricular ejection fraction was +/- 14 units. Measurements of left ventricular ejection fraction by equilibrium technique were generally more reproducible than first pass determinations because the variability caused by study acquisition, observer analysis, and residual errors was smaller. The method of variance components appears to be well suited to the evaluation of quantitative biological measurements in clinical use. The popularity of established procedures may obscure the lack of basic information about method evaluation.

Adult↗
PubMed1987

Reproducibility of determination of right ventricular ejection fraction by radionuclide imaging: assessment by the statistical method of variance components.

Confidence limits for single and repeat measurements of right ventricular ejection fraction (RVEF) were established by means of a model based on the statistical method of variance components. A total of 80 subjects (age 23 to 74 years) were examined by two radionuclide methods 1) gated first-pass (fp) technique performed in a standard 30 degrees right anterior oblique projection, and 2) multigated equilibrium imaging (muga) in an individual left anterior oblique view, applying with both methods separate end-diastolic and end-systolic ventricular regions of interest. Values obtained by fp technique were clearly higher than those measured by the muga approach, and the correlation between them was only fair: RVEFmuga = 0.48 RVEFfp + 0.13; r = 0.73; SEE = 0.08. The 95% confidence limits for a single measurement were with the fp technique: 'true' RVEF = measured RVEF +/- 6 EF-units compared to +/- 16 units with the muga method. At repeat determination within an interval of four weeks, the minimal changes in measured RVEF that were statistically significant at the 5% level were with the fp technique +/- 8 units with the same observer on both occasions and +/- 9 units with different observers. Corresponding figures with the muga method were +/- 16 and +/- 22 units, respectively. The minimal changes in a subject's 'true' RVEF necessary to produce a significant change in measured RVEF were with fp technique +/- 14 units for the same observer and +/- 17 units for different observers, compared to +/- 30 and +/- 41 units with the muga method. In conclusion, the variability with the muga approach was far greater than with the fp technique and the consequent reproducibility so poor as to preclude meaningful measurement of RVEF by the muga method.

Adult↗
PubMed1987

Effect of i.v. lignocaine on pain and the endocrine metabolic responses after surgery.

Pain intensity, and blood glucose and plasma cortisol concentrations were measured following abdominal hysterectomy in 18 patients allocated randomly to receive either i.v. lignocaine 1.5 mg kg-1 plus 2 mg kg-1 h-1, or saline. The administration of lignocaine resulted in plasma concentrations between 1.5 and 2.0 micrograms ml-1 during the 2-h study period. However, the administration of lignocaine i.v. had no effect on the intensity of pain after surgery, or on the adrenocortical and hyperglycaemic responses to surgery.

Adult↗
PubMed1986

Left ventricular ejection fraction during anaesthetic induction: comparison of rapid-sequence and elective induction.

A randomized clinical trial was conducted in 14 women, aged 24-60 years, to compare the effects of rapid-sequence induction of anaesthesia and elective induction on heart rate, blood pressure and left ventricular ejection fraction (LVEF). None of the patients suffered from heart or lung diseases, and all were scheduled for hysterectomy. Cuff blood pressure was measured repeatedly by an automatic recording device, and heart rate and LVEF were monitored by a portable nonimaging nuclear probe. In seven patients, a rapid-sequence induction was performed following preoxygenation and with simultaneous injection of thiopentone (5 mg X kg-1) and succinylcholine, without starting manual ventilation until the airway was secured with the endotracheal tube. In another seven patients, elective induction was carried out by sequential administration of the same drugs. Forty seconds after laryngoscopy and intubation mean blood pressure had increased by 38 per cent and heart rate by 29 per cent from preintubation values in the rapid sequence induction group, compared to 30 and 12 per cent respectively, in the elective induction group (p less than 0.05). Similar decreases in LVEF was observed in both groups, from 0.60 to 0.42 in the elective induction group, and from 0.60 to 0.41 in the rapid-sequence induction group. The equal depression of LVEF indicates that laryngoscopy and intubation produce, with both induction regimens, sudden impairment of cardiac function. The more pronounced hypertension and tachycardia observed during rapid-sequence induction suggests a higher myocardial oxygen consumption which may represent a serious additional burden for the poorly perfused heart.

Adult↗
PubMed1986

Auditory evoked potentials during isoflurane anaesthesia.

Brainstem auditory evoked potentials (BAEP) were determined in 12 volunteers. The effect of isoflurane anaesthesia on BAEP was determined in six patients. Body temperature and end-tidal CO2% were controlled. Increasing end-tidal isoflurane concentration from 0.6-2.4% increased BAEP wave I, III and V latencies. The amplitude of wave V decreased with increasing isoflurane concentration. Thus a dose-related change was demonstrated between end-tidal concentration of isoflurane and BAEP latencies.

Adult↗
PubMed1986

Peroperative buprenorphine: do high dosages shorten analgesia postoperatively?

Fifty-two patients undergoing biliary surgery were investigated in a prospective randomized study, in which they received buprenorphine 10, 20, 30, and 40 micrograms X kg-1, respectively, as sole intravenous analgesic as a bolus 15 min before induction of anaesthesia. The anaesthetic was uneventful in all four groups, although when receiving 10 and 20 micrograms X kg-1 almost two-thirds of the patients needed supplemental analgesics during the operation. When receiving buprenorphine in the dosage of 30 and 40 micrograms X kg-1, 50% of the patients requested an analgesic within 5 min of extubation. In contrast, when receiving 10 and 20 micrograms X kg-1 none of the patients requested an analgesic within 1 h of the operation. These findings accord to a certain extent with the presence of a bell-shaped dose-response curve for buprenorphine in humans.

Biliary Tract Surgical Procedures↗
PubMed1986

Lack of effect of intravenous lidocaine on hemodynamic responses to rapid sequence induction of general anesthesia: a double-blind controlled clinical trial.

A double-blind, randomized trial was conducted in 16 women aged 20-48 yr, to assess the effect of intravenous lidocaine on the circulatory responses to rapid sequence induction of general anesthesia. None of the patients suffered from heart or lung diseases, all were scheduled for hysterectomy, and all were premedicated with 0.3 mg/kg diazepam orally 2 hr beforehand. Induction, preceded by preoxygenation, included simultaneous injection of thiopental and succinylcholine, without starting manual ventilation until the airway was secured with the endotracheal tube. Two minutes before laryngoscopy and intubation half of the patients received lidocaine, 1.5 mg/kg, intravenously (IV). The other half received an equal volume of saline. Cuff blood pressure was measured repeatedly by an automatic recording device, and heart rate and left ventricular ejection fraction (LVEF) were monitored by a portable nonimaging nuclear probe. After laryngoscopy and intubation, mean blood pressure increased 46%, heart rate 57%, and the rate pressure product (RPP) 84% from control values in patients given lidocaine, compared to 45, 66, and 113%, respectively, in the saline group (P greater than 0.05). Pronounced, but similar decreases in LVEF were observed in the two groups, to 0.40 from 0.65 in the lidocaine group and to 0.41 from 0.65 in the saline group. In all patients, RPP reached a level considered potentially dangerous to patients with ischemic heart disease. We conclude that lidocaine, 1.5 mg/kg IV, 2 min prior to laryngoscopy and intubation does not prevent hemodynamic reactions evoked by rapid sequence induction.

Adult↗
PubMed1986

Comparison of oral controlled release morphine and epidural morphine in the management of postoperative pain.

Oral controlled release morphine (CRM) was compared in a double-blind study with epidural morphine (EM) for postoperative pain relief in 20 patients undergoing knee arthrotomy under epidural anesthesia. Ten patients received 30 mg CRM orally and saline epidurally (CRM group), and ten patients received placebo tablets orally and 4 mg morphine epidurally (EM group), both at the time of skin incision and then every 8 hr for 48 hr during which patients evaluated pain intensity using a visual analog scale. Nine of the ten patients in the EM group had good relief of pain throughout the study period. Seven of the ten patients in the CRM group needed rescue analgesics within 6 hr of the initiation of the study (P less than 0.01). We conclude that CRM is not suitable for the control of early postoperative pain, whereas epidural morphine is excellent.

Administration, Oral↗
PubMed1985

Left ventricular performance monitored by radionuclide cardiography during induction of anesthesia.

Radionuclide cardiography with 99mTc-labeled erythrocytes was carried out in three different studies comprising 20 female patients without heart or lung diseases. Left ventricular ejection fraction (LVEF) and other hemodynamic variables were measured immediately before and during induction of anesthesia (thiopental, N2O/O2, succinylcholine, laryngoscopy + oral intubation, halothane). In study 1, serial measurements of LVEF, left ventricular volume, and derived variables were obtained by gamma camera in seven patients using 3-min sampling periods. In Studies 2 and 3, LVEF was monitored serially in seven and six patients, respectively, by a portable, nonimaging probe (nuclear stethoscope) at 1-min intervals or less. The induction period was prolonged to last 24 min in studies 1 and 2, against 9 min in study 3. In studies 1 and 2 there was an increase in blood pressure and heart rate after thiopental and after laryngoscopy and intubation. In study 3 a similar increase was observed after intubation. In the gamma camera study LVEF decreased from 0.72 to 0.53 after thiopental, with no further decrease during intubation. This decrease was accompanied by an increase in end-systolic volume and a decrease in the ratio: systolic cuff pressure/end systolic volume, whereas end-diastolic volume and cardiac index remained unchanged. In the nuclear stethoscope studies, LVEF decreased both after thiopental and after intubation, in study 2 from 0.68 to 0.38 and from 0.53 to 0.41, respectively; in study 3 from 0.69 to 0.53 and from 0.57 to 0.44, respectively. Our observation, in healthy, female individuals, provide an impetus for further noninvasive radionuclide studies during anesthesia in patients with cardiovascular disease.

Adult↗