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H A Adams

Publications and source records attributed to H A Adams.

At least 73 records · Page 4Linked to original sources
PubMed1995

[Intra-abdominal bleeding after myocardial infarction with cardiopulmonary resuscitation and thrombolytic therapy].

Adverse effects of resuscitation due to closed-chest cardiac massage are common, and the incidence is increased when an incorrect technique is used. Nevertheless, thrombolytic therapy of a myocardial infarction can become necessary even after cardiopulmonary resuscitation (CPR). In these patients, the risk of thrombolytic therapy-induced bleeding is immanent. CASE REPORTS. Within 9 months, two male patients aged 44 and 52 years were admitted to the intensive care unit after out-of-hospital CPR for myocardial infarction with cardiac arrest. In both cases, thrombolytic therapy was undertaken due to the cardiovascular situation or echocardiographic results. Thrombolytic therapy was successful with regard to the ECG changes, but a few hours later both patients demonstrated increasing cardiovascular instability. After abdominal sonography, intra-abdominal bleeding was suspected. Emergency laparotomy became unavoidable, although the coagulation profile was severely impaired in both patients (Tables 1 and 2). Anaesthetic management was characterised by introduction of central venous and intra-arterial catheters, replacement of volume and oxygen carriers using large-bore IV lines, restoration of coagulation factors with fresh frozen plasma, and the choice of "modified neuroleptanaesthesia" with blood pressure-adjusted, small doses of fentanyl, midazolam, and pancuronium. Intraoperatively, a liver injury due to closed-chest cardiac massage was found in both cases. The postoperative courses were complicated by respiratory problems, which led to prolonged mechanical ventilation, but both patients survived without remarkable neurological deficits. CONCLUSION. In patients with thrombolytic therapy after CPR and persisting cardio-vascular instability, a resuscitation injury with consequent haemorrhagic shock should be suspected. For diagnosis, chest X-ray films and abdominal and thoracic sonography are useful and practicable, even at the bedside. Anaesthetic management should focus on adequate monitoring, replacement of volume and oxygen carriers, fast restoration of plasma coagulation, and careful, blood pressure-adjusted maintenance of anaesthesia.

Abdomen↗
PubMed1995

[Hygienic aspects of emergency care: principles, requirements and reality].

In preclinical emergency and rescue medicine, on-target and often improvised and smooth work is essential. Thus, some reductions of clinical standards must be accepted but cannot excuse fundamental mistakes. Hygienic protection of patients and medical staff are both equally important; however, preserving the vital functions of patients deserves top priority. In Germany, official guidelines govern the hygienic equipment of ambulance cars and hygienic management during and after transport both in routine and special cases. Disinfection of skin, hands and surfaces and hygienic protection of the medical staff predominate in daily work. Standard hygienic procedures during application of venous leads, intubation and artificial ventilation and correct handling of sterile materials should also be considered. The main goal of teaching is routine establishment of basic hygienic procedures, and, in addition, creation of sufficient hygienic basic knowledge for assessment and control of unusual situations.

Ambulances↗
PubMed1995

[Total intravenous anesthesia (TIVA) in geriatric surgery. S-(+)-ketamine versus alfentanil].

In this prospective, randomized study, two regimens of total intravenous anaesthesia (TIVA), with propofol and S(+)-ketamine (S-ketamine) and with propofol and alfentanil, were compared with reference to endocrine stress response, circulatory effects and recovery. METHODS. The investigation was conducted in two groups of 20 ASA I-III patients over 60 years of age who were scheduled for endoprothetic orthopaedic surgery. After oral premedication with midazolam, patients received a TIVA with body-weight-adjusted doses of propofol, and S-ketamine or alfentanil as the analgesic component. For CPPV (PEEP 5 mbar), air and oxygen (FiO2 33%) were used. For muscle relaxation, patients of both groups received vecuronium in body-weight-adjusted doses. Blood samples were taken through a central venous line at seven time points before induction of anaesthesia and on the first morning after the operation also for analysis of epinephrine, norepinephrine (by HPLC/ECD), and ADH, ACTH and cortisol (by RIA). In addition, SAP, HR, arterial oxygen saturation, recovery from anaesthesia and side effects were observed. RESULTS. The two groups had comparable group mean values for age (S-ketamine group 71 years, alfentanil-group 70 years), other biometric data, and duration of anaesthesia and operation (Table 1). Plasma levels of epinephrine, norepinephrine (Table 2, Fig. 1), ADH (Table 2, Fig. 2) ACTH and cortisol (Table 2, Fig. 3) were higher in the S-ketamine-group (P < 0.05) owing to the intraoperative course of these endocrine parameters. Before induction, and on the first morning after the operation, levels were comparable between the groups. 5 min after the induction of anaesthesia, SAP and HR (Table 3) were significantly lower in the alfentanilgroup (P = 0.001). Recovery from anaesthesia (orientation with respect to person and location) was faster in the alfentanilgroup (16 vs 39 min, P = 0.001). An arterial oxygen saturation below 90% was observed in 7 patients in the S-ketamine- and 13 patients in the alfentanilgroup (P = 0.03). Four patients with S-ketamine reported dreams, and 1 dream was judged negative. Postoperative emesis was found in 6 patients in the S-ketaminegroup and 12 patients in the alfentanilgroup (P = 0.03). All patients said they would agree to undergo the same anaesthetic technique again. CONCLUSIONS. Considerable differences were found in the endocrine stress response of the two groups. With respect to endocrine response and circulation, TIVA with propofol and S-ketamine had sympathomimetic properties with positive circulatory effects and led to moderate endocrine stimulation. This should be kept in mind in patients with hypotension, hypothyrosis, or adrenocortical insufficiency; because "eustress" might be beneficial in this group of patients. On the other hand, TIVA with propofol and alfentanil showed sympatholytic properties, with negative circulatory effects and a remarkable reduction of endocrine stress response. This might be beneficial in patients with hypertension and states of endocrine hyperfunction. Both regimens were accompanied by such typical side effects as dreams, delayed recovery, reduced ventilation, and emesis, which should also be considered.

Aged↗
PubMed1995

[Analgesia and sedation on patients with sepsis syndrome].

AIMS AND PATHOPHYSIOLOGY: Intensive care patients are exposed to a number of noxious stimuli. They require individual analgesia and sedation to reduce and moderate the stress response to endogenous and exogenous stressors. In patients with SIRS (systemic inflammatory response syndrome), pathophysiological conditions with multiple organ dysfunction or failure demand special efforts and a specific regimen of analgosedation. The main goals are the absence of cardiocirculatory depression or, if at all possible, cardiocirculatory stabilization, absence of negative pulmonary, renal, hepatic and immunological side effects, preservation of a moderate stress response, and vertical and horizontal control appropriate to the clinical situation. CHARACTERIZATION OF ANALGETICS AND SEDATIVES: Amongst the analgesic drugs, opioids and morphine have moderate cardiocirculatory side effects, but reduce the intestinal motility. Due to intrinsic sympathomimetic activity, ketamine has stabilizing cardiocirculatory effects, reduces the exogenous catecholamine requirement and has no negative gastrointestinal side effects. Amongst the sedative drugs, midazolam has only moderate cardiocirculatory side effects. Propofol has cardiovascular depressant properties, but horizontal control of propofol sedation is excellent. CONCLUSION: The pharmacological profile of analgesic and sedative components suggests, that the combination of ketamine and midazolam can be recommended for analgosedation of patients with SIRS. This is supported by several clinical investigations. In specific situations, that require excellent vertical control, the combination of ketamine and propofol should be preferred.

Analgesics↗
PubMed1994

[Total i.v. anesthesia with S-(+)-ketamine in orthopedic geriatric surgery. Endocrine stress reaction, hemodynamics and recovery].

UNLABELLED: Clinically-used ketamine is a racemic mixture of two isomers, S-(+)- and R-(-)-ketamine. Previous investigations showed the anaesthetic potency of S(+)-ketamine to be three times higher than that of R-(-)-ketamine. It was the aim of this study to compare the effects of S-(+)-ketamine and racemic ketamine on endocrine and cardiovascular parameters, recovery, and side effects in geriatric patients during total intravenous anaesthesia (TIVA) for orthopaedic surgery. METHODS: Forty patients over 60 years of age scheduled for elective hip or knee replacement were investigated in a double-blind, randomised design. For induction of TIVA, patients received 0.1 mg midazolam, 0.5 mg atropine, 1 mg/kg S(+)-ketamine or 2 mg/kg racemic ketamine, respectively, 2 mg vecuronium, and 1.5 mg/kg suxamethonium. After intubation and relaxation with a total dose of 0.1 mg/kg vecuronium, a continuous infusion of 2 mg/kg per hour S-(+)- or 4 mg/kg per hour racemic ketamine was administered throughout surgery. Blood samples were taken through a central venous catheter at seven time-points, before induction as well during and after surgery, until the 1st postoperative morning for analysis of adrenaline, noradrenaline (by high-pressure liquid chromatography with electrochemical detection), anti-diuretic hormone (ADH), adrenocorticotropic hormone (ACTH), cortisol (by radioimmunoassay), glucose, and lactate. In addition, systolic arterial pressure (SAP), heart rate (HR), and arterial oxygen saturation were measured, and the time intervals between the end of ketamine infusion and the return of consciousness and orientation were protocolled. The incidence and assessment of dreams and other side effects were reported by the patients. RESULTS: Biometric data of the groups were comparable, the mean age of both groups being 68 years. Plasma adrenaline, noradrenaline, ADH, ACTH, cortisol, and glucose as well as SAP and HR increased significantly (P < 0.05) during the course of anaesthesia. The influence on lactate levels was not significant. There were no differences between S(+)- and racemic ketamine with respect to these parameters. Three patients in the ketamine-racemate group showed severe arterial hypertension and were withdrawn from the study. Recovery clearly improved after administration of S(+)-ketamine compared to the racemate. Simple orders were followed after 2.0 +/- 3.4 versus 4.9 +/- 6.8 min (P = 0.07), orientation with respect to person returned after 5.7 +/- 4.0 versus 14.6 +/- 10.0 min (P < 0.001) and spatial orientation after 8.2 +/- 5.4 versus 17.4 +/- 9.7 min (P < 0.001). After racemic ketamine, 1 patient remembered a negative dream and 1 patient a positive dream. In the S(+)-group, 1 positive dream was reported. No intraoperative awareness was reported, and all patients would accept the same anaesthesia again. CONCLUSIONS: Increases in cardiovascular parameters and insufficient reduction of the stress response with respect to ADH, ACTH, and cortisol seem to require a more potent hypnotic element during TIVA with ketamine. With regard to endocrine and cardiovascular parameters, the pharmacodynamic effects of racemic and S-(+)-ketamine were comparable. Because of the significant improvement in recovery and the reduced quantitative drug load, S-(+)-ketamine offers a clinical advantage compared with currently used racemic ketamine.

Aged↗
PubMed1994

[Endocrine stress reaction, hemodynamics and recovery in total intravenous and inhalation anesthesia. Propofol versus isoflurane].

This prospective, randomised study compared total intravenous anaesthesia (TIVA) and inhalation anaesthesia with respect to endocrine stress response, haemodynamic reactions, and recovery. METHODS. The investigation included two groups of 20 ASA I-II patients 18-60 years of age scheduled for orthopaedic surgery. For premedication of both groups, 0.1 mg/kg midazolam was injected IM. Patients in the propofol group received TIVA (CPPV, PEEP 5 mbar, air with oxygen FiO2 33%) with propofol (2 mg/kg for induction followed by an infusion of 12-6 mg/kg.h) and fentanyl (0.1 mg before intubation, total dose 0.005 mg/kg before surgery, repetition doses 0.1 mg). For induction of patients in the isoflurane-group, 5 mg/kg thiopentone and 0.1 mg fentanyl was administered. Inhalation anaesthesia was maintained with 1.2-2.4 vol.% isoflurane in nitrous oxide and oxygen at a ratio of 2:1 (CPPV, PEEP 5 mbar). For intubation of both groups, 2 mg vecuronium and 1.5 mg/kg suxamethonium were injected, followed by a total dose of 0.1 mg/kg vecuronium. Blood samples were taken through a central venous line at eight time points from before induction until 60 min after extubation for analysis of adrenaline, noradrenaline (by HPLC/ECD), antidiuretic hormone (ADH), adrenocorticotropic hormone (ACTH), and cortisol (by RIA). In addition, systolic arterial pressure (SAP) heart rate (HR), arterial oxygen saturation (SpO2), and recovery from anaesthesia were observed. RESULTS. Group mean values are reported; biometric data from both collectives were comparable (Table 1). Plasma levels of adrenaline (52 vs. 79 pg/ml), noradrenaline 146 vs. 217 pg/ml), and cortisol (82 vs. 165 ng/ml) were significantly lower in the propofol group (Table 2, Figs. 1 and 3). Plasma levels of ADH (4.8 vs. 6.1 pg/ml) and ACTH (20 vs. 28 pg/ml) did not differ between the groups (Table 2, Figs 2 and 3). SAP (128 vs. 131 mmHg) was comparable in both groups, HR (68/min vs. 83/min) was significantly lower in the propofol group, and SpO2 (97.1 vs 97.4%) showed no significant difference (Table 3). Recovery from anaesthesia was slightly faster in the propofol group (following of simple orders 1.9 vs. 2.4 min, orientation with respect to person 2.4 vs. 3.4 min, orientation with respect to time and space 2.8 vs. 3.7 min), but differences failed to reach statistical significance. CONCLUSIONS. When compared with isoflurane inhalation anaesthesia, moderation of the endocrine stress response was significantly improved during and after TIVA with propofol and fentanyl. Slightly shorter recovery times did not lead to an increased stress response. With respect to intra- and postoperative stress reduction, significant attenuation of sympatho-adrenergic reaction comparable SAP and reduced HR, sympatholytic and hypodynamic anaesthesia with propofol and fentanyl seems to be advantageous for patients with cardiovascular and metabolic disorders. For this aim, careful induction and application of individual doses is essential.

Adolescent↗
PubMed1993

[Indications for the use of human albumin in anesthesia and intensive care medicine].

The plasmatic albumin concentration (3.5-4.5 g/dl) represents about 60% of the total plasma protein. Only 25-40% of whole albumin belongs to the intravascular pool, the majority is distributed in the interstitial space especially of the skin. Main physiological effects of plasmatic albumin are the control of the plasmatic volume by preservation of the colloid oncotic pressure (COP) and the plasmatic transport including the binding of drugs. The COP is the main factor for fixation of the intravascular volume and the prevention of interstitial oedema. The acute volume effects of albumin can be totally replaced by synthetic colloids like hydroxyethyl starch, gelatine, and dextran, with the exception of volume substitution in neonates. In intensive care medicine, the COP-effects of albumin can almost be replaced by synthetic colloids as well. A positive COP-effect by administration of human or synthetic macromolecules is unlikely in patients with capillary leak. For therapy control, the direct measurement of COP is superior to the calculation derived from albumin or total protein. The global clinical situation of the patient and the course of haematocrit should be respected as well. For prevention of interstitial pulmonary oedema, a COP of 15-20 mmHg should be achieved. Up to now, no clinical study verified a positive effect of albumin substitution regarding outcome or incidence of complications in intensive-care patients. Thus, an albumin therapy to maintain a COP of 15-20 mmHg in intensive-care patients is only recommended if a capillary leak is unlikely and the dose limits of synthetic colloids are attained.(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesia, General↗
PubMed1993

[Anesthesia for patients with pheochromocytoma. Our own results and a review].

Phaeochromocytoma is a rare, autonomous catecholamine secreting tumour of the sympatho-adrenergic system. Due to the continuous or phasic secretion of catecholamines from the tumour, patients present with hypertensive crisis, episodic or sustained hypertension or arrhythmia. Excessive intraoperative hypertension unable to control by usual methods should be considered to be a phaeochromocytoma. Surgical removal of identified lesions should be performed under controlled conditions and after sufficient preparation of the patient. Preoperative alpha-adrenergic blockade with prazosin and phentolamine allows an increase in intravascular volume and affords some protection against excessive intraoperative hypertension. The use of beta-adrenergic antagonists is only recommended in patients with arrhythmia (especially tachycardia) and after induction of alpha-adrenergic blockade. For operation of phaeochromocytoma, modified neuroleptic anaesthesia is a useful anaesthetic technique. Intraoperative hypertension is controlled with sodium nitroprusside and phentolamine. Intravascular volume is substituted under CVP or PAP control, and epinephrine or norepinephrine are used if necessary. During the postoperative period, hypotension or hypertension or left ventricular failure may occur. In an own study, 9 patients with phaeochromocytoma were investigated, 7 patients with other operations of the adrenal glands served as controls. Despite specific preoperative preparation and intraoperative use of antihypertensive drugs, excessive increases in blood pressure could not be avoided in some cases. Extremely high plasma levels of catecholamines up to the factor 1,000 of the normal range were found. Even in controls, considerable increases in blood pressure and catecholamine levels were observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

[The effect of flumazenil on the endocrine stress reaction following modified neuroleptanesthesia].

This study was undertaken to investigate in a prospective randomized way the influence of the benzodiazepine antagonist flumazenil on endocrine stress response and haemodynamic parameters after modified neuroleptanaesthesia. A total of 24 patients (ASA scores I or II) aged between 18 and 60 who were scheduled for major gynaecological surgery, were investigated. For modified neuroleptanaesthesia, midazolam, fentanyl and vecuronium were administered in standardized doses. After extubation, patients of the flumazenil group received initial injections of 0.2 mg flumazenil to antagonize the residual effect of midazolam and additional doses of 0.1 mg per minute until the desired level of vigilance was reached (awareness of person, time and place). In the control group no flumazenil was used. Endocrine stress parameters and haemodynamic parameters were measured at 7 different times, from before induction of anaesthesia up to 60 minutes after the operation. In both groups, a marked increase in endocrine stress response was observed. Adrenaline, noradrenaline, antidiuretic hormone, adrenocorticotropic hormone, cortisol, glucose and lactate, however, were not additionally influenced by the antagonism. No influence of flumazenil on mean arterial pressure, heart rate and arterial oxygen saturation was observed. After modified neuroleptanaesthesia, a careful antagonism of midazolam with small doses of flumazenil is not disadvantageous with respect of endocrine stress response and haemodynamic reactions.

Adolescent↗
PubMed1993

[Endocrine and hemodynamic effects of naloxone following modified neuroleptanesthesia].

This study was undertaken to investigate the influence of the opiate-antagonist naloxone on the endocrine stress response and haemodynamic parameters after modified neuroleptanaesthesia in a randomized, prospective design. A total number of 22 patients (ASA-scores I or II) between 18 and 60 years scheduled for major gynaecologic surgery were included. For modified neuroleptanaesthesia, midazolam, fentanyl and vecuronium were administered in standardized doses. After extubation, patients of the naloxone-group received injections of 2 x 0.1 mg naloxone; in controls, no naloxone was used. Endocrine stress parameters and haemodynamic parameters were measured 7 times before induction of anaesthesia and up to 60 minutes after the operation. In both groups, remarkable increases in adrenaline, noradrenaline, antidiuretic hormone, adrenocorticotropic hormone, cortisol, glucose and lactate took place in the postoperative period. This stress response was comparable in both groups and not increased by naloxone. No significant influence of naloxone on mean arterial pressure, heart rate and arterial oxygen saturation was observed. After neuroleptanaesthesia, a careful opiate antagonism with small doses of naloxone is not disadvantageous with respect to endocrine stress response and haemodynamic reactions.

Adolescent↗
PubMed1992

[Endocrine stress response in cataract operations with local anesthesia].

This study was undertaken to investigate the endocrine stress response during cataract surgery in local anaesthesia (LA) with or without additional sedation with midazolam (Dormicum). 20 patients for cataract surgery in LA were randomly allocated to the midazolam-group (before injection of LA, sedation with single doses of 1 mg midazolam until the patient was sleeping, but awakeable), and to the control-group without sedation. Premedication and LA were standardized. The investigation was performed at 7 measuring points starting at the arrival in the preparation room up to 30 min after surgery. Adrenaline in plasma was significantly lower in the midazolam-group. Intraoperatively, adrenaline increased in the control-group and decreased in the midazolam-group. In time course, noradrenaline in plasma decreased in the midazolam-group, in contrast to the control-group. With respect to ADH, ACTH and cortisol, no significant differences were found in group levels or time course, and concentrations remained within normal range. In contrast to the control-group, mean arterial pressure decreased in the midazolam-group during the course of time. There were no differences in heart rate or arterial oxygen saturation between the two groups. Local anaesthesia and premedication were sufficient to prevent psychic and surgical stressors. The slight sympathoadrenergic response in the control-group was significantly reduced by small doses of midazolam. Thus, a careful supplementation of local anaesthesia with midazolam appears advantageous for patients with cardiovascular disorders.

Adrenocorticotropic Hormone↗
PubMed1992

[Studies using S-(+)-ketamine on probands. Endocrine and circulatory reactions, recovery and dream experiences].

UNLABELLED: Clinically used ketamine is a racemic mixture of two isomers, S(+)- and R(-)-ketamine. The anaesthetic potency of S(+)-ketamine was found to be three times higher than that of R(-)-ketamine. It was the aim of this study to compare the effects of racemic ketamine and S(+)-ketamine on endocrine and cardiovascular parameters, recovery and psychomimetic reactions in young healthy volunteers. METHODS: 6 women and 4 men between 23 and 38 years were investigated twice in a randomized double blind cross-over design receiving injections of 2 mg/kg BW racemic ketamine or 1 mg/kg BW S(+)-ketamine at an interval of at least 7 days. Samples were taken from a central venous catheter before and 1, 3, 5, 10, 15, 30, 60 and 120 min after injection for analysis of adrenaline, noradrenaline (by high pressure liquid chromatography with electrochemical detection), ADH, ACTH, cortisol (by radio immuno assay), glucose, lactate and free glycerol. In addition, SAP, HR, and arterial oxygen saturation were measured, and return of consciousness and orientation were protocoled. Incidence and assessment of dreams were reported by the volunteers. RESULTS: Adrenaline, noradrenaline, ACTH, cortisol, lactate and free glycerol in plasma as well as SAP and HR increased significantly after injection of both racemic ketamine and S(+)-ketamine. The influence on ADH and glucose was not significant. There were no differences between racemic ketamine and S(+)-ketamine in these parameters. Recovery was significantly improved after administration of S(+)-ketamine. Simple orders were followed after 7.9 +/- 1.1 vs. 9.2 +/- 1.2 min (P = 0.004). Orientation with respect to the person returned after 9.0 +/- 1.8 vs. 11.5 +/- 2.5 min (P = 0.004); with respect to time and location after 10.1 +/- 2.1 min vs. 13.4 +/- 4.0 min (P = 0.007). 18 dreams were reported; assessment was positive in 13 cases and indifferent in 5 cases, none was negative. In 7 of 10 cases, the investigators were able to identify that S(+)-ketamine had been injected. CONCLUSION: With respect to endocrine and cardiovascular parameters, the pharmacodynamic effects of racemic and S(+)-ketamine were comparable. Because of the significant improvement in recovery and the reduced quantitative drug load, S(+)-ketamine offers a clear clinical advantage compared with currently used racemic ketamine.

Adrenocorticotropic Hormone↗
PubMed1992

[The action of S-(+)-ketamine on serum catecholamine and cortisol. A comparison with ketamine racemate].

The S(+)-isomer of ketamine has about twice the anaesthetic potency of the commercially available racemic mixture of ketamine. It is assumed that the known side-effects of ketamine are significantly reduced when administering half the usual dose with the same pharmacodynamic effect [17, 25]. The aim of the present study was to determine the haemodynamic effects, the catecholamine and cortisol plasma levels after administration of equally potent doses of S-(+)-Ketamine and racemic mixture of ketamine. In addition, the effect of premedication with i.v. midazolam was assessed. METHOD. After approval by the ethics committee and written informed consent, 30 healthy male volunteers were randomly allocated to three groups (n = 10). Group 1 received 2 mg/kg ketamine racemate, group 2 1 mg/kg S-(+)-Ketamine, and group 3 1 mg/kg S-(+)-Ketamine 5 min after i.v.-premedication with 0.1 mg/kg midazolam. Non-invasive blood pressure (BP) and heart rate (HR) were continuously recorded. Blood samples were drawn 7 min before, and 2, 4, 8, 16, 32, 64 and 128 min after drug administration. Plasma epinephrine and norepinephrine (NE) levels were determined by HPLC and cortisol plasma levels by RIA. Data were analysed with the Kruskal-Wallis test (P < or = 0.05) for differences between groups. RESULTS. HR and BP showed a significant rise after injection of racemate and isomer, without any significant differences between groups. This was also seen for norepinephrine and cortical plasma levels. Epinephrine levels, however, differed between groups, showing a significant rise after racemate compared to isomer. Premedication with midazolam, in contrast, blunted major haemodynamic and hormonal changes. DISCUSSION. The haemodynamic changes did not differ between the racemate and isomer group despite a reduced isomer dose. HR and BP rise were similar, although epinephrine levels were significantly lower after isomer than racemate. Hence we assume that the increase in the haemodynamic parameters were mainly caused by NE. Midazolam apparently prevented the centrally mediated sympathetic stimulation caused by ketamine and its isomers. Therefore, i.v. premedication with midazolam should be applied when racemate or isomer is used, especially in high-risk cardiac patients.

Adult↗
PubMed1992

[Studies using S-(+)-ketamine on probands. Computerized EEG-analysis and transcranial Doppler ultrasonography].

It has been shown in the recent literature that the anaesthetic potency of the ketamine isomer S(+)-ketamine is twice that of the racemic mixture used in clinical practice. METHODS. With approval of the local ethics committee, we investigated the effects of a bolus injection of 2 mg/kg racemic ketamine or 1 mg/kg S(+)-ketamine, respectively, on the electroencephalogram (EEG) and transcranial Doppler sonography (TCD) of the middle cerebral artery in ten healthy volunteers by means of a randomised, double-blind, cross-over design. Spectral edge frequency, total activity and activity of the alpha, beta, delta, and theta bands were assessed by bihemispheric leads using the Neurotrac system before (MZP 1) and 1, 3, 5, 10, 15, 30, 60, and 120 min after injection (MZP 2-9). Simultaneously, systolic (Vs-MCA), diastolic (Vd-MCA), and mean (Vm-MCA) blood flow velocities in the middle cerebral artery and pulsatility (Vs-Vd)/Vm were recorded. Statistics consisted of two-dimensional analysis of variance with P < 0.05 considered as significant. RESULTS. Racemic ketamine and S(+)-ketamine produced comparable effects on the EEG. Theta- and beta-activities increased between the 1st and 10th min after injection and returned to near baseline values thereafter. 120 min after injection, the absolute delta- and theta-activities were higher following racemic ketamine when compared to the S(+)-ketamine group. However, significant differences between the groups could not be confirmed statistically. TCD variables changed considerably in the course of the study without intergroup differences. Compared to the baseline values, Vs-MCA, Vd-MCA, and Vm-MCA increased significantly for the first 15 min after injection with a maximum at MZP 3. The pulsatility of the obtained Doppler waveform (Vs-Vd)/Vm showed significant decreases at MZP 2-4. CONCLUSIONS. In our study, both racemic ketamine and its isomer S(+)-ketamine produced similar EEG changes consistent with the data from earlier studies. However, the relative lower proportion of slow EEG activity at the end of the study might indicate a better recovery of cortical function following S(+)-ketamine than after racemic ketamine. Assuming a close relationship between cerebral blood flow velocity and cerebral blood flow, our TCD results suggest that both racemic ketamine and S(+)-ketamine will considerably increase cerebral blood flow in spontaneously breathing volunteers. Such an effect has been observed by others and, at least partly, can be explained by a concomitant increase in arterial carbon dioxide partial pressure.

Adult↗
PubMed1992

[The simultaneous determination of ketamine and midazolam using high pressure liquid chromatography and UV detection (HPLC/UV)].

In order to prevent some negative side effects of ketamine during "dissociative anaesthesia", this substance is regularly combined with benzodiazepines, e.g., midazolam. This study was undertaken to develop a simple and effective method for the simultaneous detection of ketamine and midazolam in plasma by high-pressure liquid chromatography with UV-detection (HPLC/UV). METHODS. The chromatographic system consisted of a 300 x 3.9-mm C18 column for reversed-phase chromatography and a mobile phase of 30% acetonitrile and 70% 0.05 M sodium phosphate buffer, pH 4.45. The flow rate was 1 ml/min. UV-detection took place at a wavelength of 210 nm. Blood samples were preferably taken from a central venous or arterial line. After plasma separation, 1 microgram (100 microliters) etidocaine was added to 1 ml plasma as an internal standard. The samples were alkalinised and extracted with ether, followed by back-extraction of the organic phase in 250 microliters 0.05 N sulphuric acid; 50 microliters of this solution was injected into the system. RESULTS. Sample preparation by trained personnel was reliable and led to adequate results. Separation of ketamine and midazolam was very satisfactory. Standard curves for both drugs were linear from 15-4000 ng/ml (ketamine r = 0.9998; midazolam r = 0.9996). Recovery rates for ketamine in plasma were above 95%, for midazolam 70%-75%. Coefficients of variation for ketamine in plasma were between 0.6% and 1.3%, for midazolam between 2.0% and 2.6%. The detection limit was lower than 5 ng/ml. CONCLUSION. The method is suitable for clinical practice and allows the simultaneous detection of two anaesthetics in wide-spread combined use.

Chromatography, High Pressure Liquid↗