Biomedical subjects

J Motsch

Publications and source records attributed to J Motsch.

At least 91 records · Page 5Linked to original sources

PubMed1996

Semi-continuous versus injectate cardiac output measurement in intensive care patients after cardiac surgery.

OBJECTIVE: Commercially available semi-continuous cardiac output (SCCO) monitoring systems are based on the pulsed warm thermodilution technique. There is evidence that SCCO fails to correlate with standard intermittent bolus cardiac output (ICO) in clinical situations with thermal instability in the pulmonary artery. Furthermore, ventilation may potentially influence thermodilution measurements by enhanced respiratory variations in pulmonary artery blood temperature and by cyclic changes in venous return. Therefore, we evaluated the correlation, accuracy and precision of SCCO versus ICO measurements before and after extubation. DESIGN: Prospective cohort study. SETTING: Intensive care unit (ICU) of a university hospital. PATIENTS AND PARTICIPANTS: 22 cardiac surgical ICU patients. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: SCCO and ICO data were obtained at nine postoperative time points while the patients were on controlled mechanical ventilation. Further sets of measurements were taken during the weaning phase 20 min before extubation, and 5 min, 20 min and 1 h after extubation. SCCO and ICO measurements yielded 286 data pairs with a range of 1.8-9.9 l/min for SCCO and 1.9-9.8 l/min for ICO. The correlation between SCCO and ICO was highly significant (r = 0.92; p < 0.01), accompanied by a bias of -0.052 l/min and a precision of 0.56 l/min. Correlation, accuracy and precision were not influenced by the mode of respiration. CONCLUSIONS: Our results demonstrate excellent correlation, accuracy and precision between SCCO and ICO measurements in postoperative cardiac surgical ICU patients. We conclude that SCCO monitoring offers a reliable clinical method of cardiac output monitoring in ICU patients following cardiac surgery.

Aged↗

PubMed1996

[Premedication of coronary risk patients--results of a survey].

AIM: The perioperative risk in patients undergoing coronary artery bypass grafting (CABG) might be influenced by premedication procedures. This study was undertaken to evaluate present premedication regimens in CABG patients in Germany. METHODS: Using a detailed written questionnaire, each of the 58 German centres of cardioanaesthesia were asked to complete it. RESULTS: 37 (64%) of all questionnaires were returned and analysed. All centres used orally administered drugs for premedication in the evening before the operation. Flunitrazepam is the most often administered drug (54%), followed by dipotassium clorazepat (8%), and diazepam (8%). Premedication in the morning on the day of surgery is performed orally in 29 centres (78%), of which 18 centres (49%) prefer flunitrazepam and 6 centres (16%) midazolam as first choice. In contrast, 7 centres (19%) used intramuscularly administered regimens. 5 centres (14%) combined intramuscularly opioids with sedatives for that indication. If anaesthesia was induced late in the morning or in the afternoon, respectively, 11 centres (30%) administered additional benzodiazepines early in the morning. 68% of all centres maintained the administration of chronic treatment with ss-blockers until the morning of the operating day. Chronic treatment with nitrates is continued in 65%, treatment with calcium-channel blockers in 62%. Angiotensin converting enzyme inhibitors are continued in 30%, alpha 2-agonists in 27%, other antihypertensive drugs in 19%, and inotropic glycosids in 11%. 31 of 37 centres (84%) discontinued the administration of acetylsalicylic acid 5 or more days prior to surgery, but 68% tolerate individual exceptions from this principle. CONCLUSIONS: The results of our survey indicate that most of the German cardioanaesthesia centres use oral premedication regimens in patients undergoing coronary revascularisation. Anti-anginal medications, with the exception of anti-platelet agents, were continued until the day of surgery in most of the centres.

Cardiovascular Agents↗

PubMed1996

[Etomidate versus propofol for anesthesia in ambulatory cardioversion].

OBJECTIVE: This study compared the two short-acting intravenous anaesthetic agents, etomidate in lipid emulsion and propofol, for anaesthesia during elective outpatient cardioversion. METHODS: After institutional approval and informed consent, 40 patients (ASA II/III) scheduled for cardioversion were studied. Patients with a left ventricular ejection fraction < 30% were excluded. The anti-arrhythmic medication was not discontinued, and no patient was given pharmacological premedication. Anaesthesia was induced either with etomidate (in lipid emulsion) 0.25 mg/kg or propofol 1.5 mg/kg. Both agents were administered over 30 seconds. Subsequent increments were given until the patients no longer followed verbal commands and the lid reflex was absent. Patients were allowed to breathe 40% oxygen via face mask. Artificial ventilation was performed if a patient became apnoeic for more than 20 seconds. The blood pressure was monitored continuously with the Finapres noninvasive blood pressure monitor, and the heart rate was recorded simultaneously. All data were collected electronically. The duration of anaesthesia was taken as the period from the start of induction until the opening of the eyes on command. For assessment of recovery from anaesthesia, patients were asked to perform a series of psychomotor tests. RESULTS: The two groups were similar in their demographic and haemodynamic baseline data. In both groups, a significant decrease in blood pressure occurred 120 seconds after anaesthesia induction, which was due to the performance of the cardioversion. Five minutes after induction, the blood pressure returned to baseline in the etomidate group, while it remained below baseline in the propofol group. Propofol caused a significant decrease in heart rate. Significantly more patients needed artificial ventilation after propofol administration because of apnoea. Involuntary muscle movements occurred only in patients receiving etomidate. The immediate emergence from anaesthesia was faster after propofol. However, 15 minutes after awakening there was no difference in psychomotor skills between the two groups. No residual psychomotor impairment was evident 60 minutes after anaesthesia in any patient. All patients were discharged four hours after the cardioversion. CONCLUSIONS: Because the recovery characteristics were similar in both groups, the occurrence of side effects may be a major factor when choosing between etomidate and propofol for outpatient cardioversion.

Adult↗

PubMed1996

Retention of antibacterial activity and bacterial colonization of antiseptic-bonded central venous catheters.

We determined how long antiseptic impregnation with silver sulphadiazine and chlorhexidine (SCC) on polyurethane central venous double- or triple-lumen catheters is retained in vivo. A total of 116 antiseptic catheters were tested for antibacterial activity in an in-vitro bioassay after various periods of iv catheterization. Segments from the subcutaneous (sc) and intravenous (iv) portions of the catheters were cultured. The results of test antiseptic catheters were compared with those from 117 noncoated control (c) catheters. Retention of antibacterial activity followed an exponential curve and lasted for up to 520 h after catheter insertion. Significant differences (P = 0.0001) between SSC and C catheters were noticed with regard to the quantitative level of bacterial colonization (SSC-sc 87 +/- 34 vs C-sc 584 +/- 122; SSC-iv 52 +/- 17 vs C-iv 286 +/- 57; all values are given as mean cfu +/- S.E.M.), and the frequency of bacterial colonization (SSC-sc 20.7% vs C-sc 38.5%, P = 0.0047; SSC-iv 18.1% vs C-iv 30.8%, P = 0.0361). There was no significant difference between the incidence of catheter-related bacteraemia in the test (n = 0) and control groups (n = 3) (P = 0.2573). Further prospective studies are required to delineate the role of antiseptic catheters in preventing catheter-related infections.

Bacteremia↗

PubMed1996

Platelet factor 4 release in patients undergoing cardiopulmonary resuscitation--can reperfusion be impaired by platelet activation?

BACKGROUND: Reperfusion following cardiac arrest is associated with a marked activation of blood coagulation. This seems to be associated with microcirculatory reperfusion disorders. The present study was designed to investigate the possible involvement of platelets in reperfusion injury following cardiac arrest. Plasma levels of platelet factor 4 (PF 4) were used as an indicator for in vivo platelet activation because PF 4 is known to be released from platelets during aggregation. METHODS: Plasma PF 4 levels (normal range: < 5IU/mL) were measured in 18 patients at predetermined time points during cardiopulmonary resuscitation (CPR). In the case of restoration of spontaneous circulation, additional blood samples were analyzed until seven days after stabilization. The PF 4 levels of four sex-matched volunteers were used as controls. RESULTS: The median of the maximum individual PF 4 levels measured during CPR was 27.5 IU/mL (range 1.2 to 90 IU/ liter; P < 0.01 versus controls). Compared with PF4 levels in control volunteers (median: 0.35 IU/mL; range 0.2 to 0.6 IU/ liter), PF 4 levels were significantly elevated in patients during CPR and in the early phase until 24 hours after restoration of spontaneous circulation (P < 0.05). CONCLUSION: A marked increase in PF 4 levels was observed during CPR and in the early phase after cardiac arrest in man. This increase in PF 4 levels has to be viewed as an indicator of platelet activation, which may play a role in the etiology of reperfusion injury and microcirculatory reperfusion disorders occurring after cardiac arrest.

Aged↗

PubMed1996

Infectious risks associated with the use of propofol.

BACKGROUND: Investigations of the Centers for Disease Control into postoperative infections have implicated extrinsically contaminated propofol. METHODS: To evaluate the infectious risk associated with intravenous anaesthetic agents, we surveyed the literature from 1971 to 1995 using the Medline database. Papers covering infections related to intravenous anaesthetic agents were included. RESULTS: The review of the literature on infections associated with propofol and other intravenous anaesthetics shows that this infectious risk is minimal and often caused by breakdowns in aseptic techniques. CONCLUSIONS: We conclude that, if standard hygienic precautions are taken, the risk of in-use contamination of intravenous anaesthetics is low. If strict hygienic guidelines are followed in handling propofol, this agent can be safely administered to patients.

Anesthetics, Intravenous↗

PubMed1996

Recovery of psychomotor function following general anaesthesia in children: a comparison of propofol and thiopentone/halothane.

The present study was undertaken to compare immediate recovery and recovery of complex psychomotor function in 20 children (aged 6-12 years) following general anaesthesia with either thiopentone/halothane or propofol. Early recovery of psychomotor skills was significantly faster in the propofol group than in the thiopentone/halothane group. Compared to preanaesthesia baseline the sedation and cooperation scores, the reaction time to visual and auditory stimuli as well as the postbox test and the flicker fusion frequency were less impaired after propofol than after thiopentone/halothane anaesthesia up to 120 min postoperatively. In the propofol group most tests reached preanaesthesia levels after 120 min, while in the thiopentone/halothane group these levels were not reattained throughout the entire study period. The results indicate that the recovery of psychomotor function in paediatric patients following general anaesthesia with propofol is significantly faster than with thiopentone/halothane. This has important implications for parental satisfaction, the time over which patients need to be monitored in the recovery room and for the discharge criteria after daycase surgery.

Anesthesia Recovery Period↗

PubMed1996

Inhaled nitric oxide selectively decreases pulmonary artery pressure and pulmonary vascular resistance following acute massive pulmonary microembolism in piglets.

Acute massive pulmonary embolism increases pulmonary artery pressure (PAP) and pulmonary vascular resistance (PVR), which may lead to early right ventricular failure and subsequent cardiocirculatory deterioration. Inhaled nitric oxide (NO) selectively dilates pulmonary vessels in vivo. Thus, inhaled NO may be useful in preventing cardiocirculatory deterioration following pulmonary embolism. We investigated the effects of inhaled NO in the acute phase of massive pulmonary microembolism in 10 anesthetized and mechanically ventilated piglets (body weight, 18 +/- 2 kg). Microspheres of 300-microns diameter were injected i.v. in an amount sufficient to initially increase mean PAP to 45 mm Hg. Forty-five minutes after pulmonary embolization, the pretreatment control values were recorded. Thereafter, the piglets inhaled 40 ppm NO, and subsequently 80 ppm NO. When 40 ppm NO was inhaled, there was a significant decrease in systolic PAP (-10.3%; 44.5 +/- 2.2 to 39.9 +/- 2.4 mm Hg; p < 0.05) and mean PAP (-9.4%; 32.9 +/- 1.3 to 29.8 +/- 1.3 mm Hg; p < 0.05). PVR was changed by -13.6% (p = 0.07). Administration of 80 ppm NO resulted in a significant decrease in systolic PAP (-12.6%; to 38.9 +/- 1.9 mm Hg; p < 0.05), mean PAP (-11.9%; to 29.0 +/- 1.4 mm Hg; p < 0.05), and PVR (-19.4%; p < 0.05) compared with pretreatment values. Discontinuation of NO inhalation was associated with an immediate return to pretreatment values. Systemic hemodynamics and the arterial and mixed venous oxygen concentrations remained unchanged. We conclude that inhaled NO following acute massive pulmonary microembolism selectively decreases PAP and PVR without influencing systemic hemodynamics in piglets.

Administration, Inhalation↗

PubMed1996

[A comparative study of the use of sevoflurane and propofol in ambulatory surgery].

UNLABELLED: Cost-containment strategies increase the demand for day-case surgery. In outpatients, a short time of stay in the post-anaesthesia care unit and a short interval to discharge home are of great importance. After general anaesthesia, mental and psychomotor functions are impaired to varying degrees by different anaesthetics. Therefore, the choice of anaesthetic may influence the discharge times of outpatients. In this study, the recovery characteristics of sevoflurane versus propofol anaesthesia were compared in adult outpatients. METHODS: With ethics committee approval and written informed consent, a total of 50 patients undergoing day-case ophthalmological or urological surgery were randomised into two groups. After a priming dose of vecuronium 0.015 mg/kg, anaesthesia was induced in all patients with propofol 2.0-2.5 mg/kg and fentanyl 2 micrograms/kg. Suxamethonium 1 mg/kg was used to provide muscle relaxation for endotracheal intubation. According to the randomisation, anaesthesia was maintained with either sevoflurane 1-3 vol.% (group 1, n = 25) or propofol (group 2, n = 25). The immediate postoperative recovery was assessed by the time to the appropriate response to different verbal commands. The quality of the overall postoperative recovery was classified by visual analogue scales, the digit-symbol substitution test (DSST), a modified Aldrete score, and the time until the ability to sit upright and walk. Overall side effects and postoperative behaviour were evaluated by a telephone interview on the day after surgery. RESULTS: Neither the study groups nor the duration of surgical procedures differed significantly. The total doses of anaesthetic used were 1.7 +/- 1.1 MAC-h sevoflurane and 631 +/- 261 mg propofol, respectively. The time intervals from the end of anaesthesia to extubation of the trachea were significantly shorter after sevoflurane than after propofol (6.6 +/- 2 min vs. 9.8 +/- 6 min). Similar results were obtained for the intervals to eye opening (7.2 +/- 2 min vs. 12.6 +/- 9 min) and hand squeezing (8 +/- 2 min vs. 13.8 +/- 11 min). The recovery of cognitive functions was significantly faster after sevoflurane when compared to propofol as evidenced by the DSST. The modified Aldrete score was significantly better in the sevoflurane group at all assessment times. Except for 30 min after anaesthesia, when sevoflurane patients complained of significantly more nausea, VAS scores were not different. No significant difference in the ability to sit and walk was found. The side effects did not differ between both groups. CONCLUSION: The results indicate that in urological and ophthalmological day surgery, the early recovery and the return of mental and psychomotor function in the first 60 min after anaesthesia is faster following sevoflurane than after propofol. No differences in ambulation times became evident. Sevoflurane may offer clinical advantages over propofol when used for maintenance of anaesthesia during outpatient surgical procedures.

Adult↗

PubMed1996

Different effect of inhaled nitric oxide on yucatan micropig with and without congenital ventricular septal defect.

A strain of Yucatan micropigs is known to have heritable ventricular septal defects (VSDs) and thus may develop overflow pulmonary hypertension. Since inhaled nitric oxide (NO) selectively dilates pulmonary vessels, we determined its hemodynamic and co-agulatory effects in this new animal model. Eight Yucatan micropigs were anesthetized with midazolam, piritramide (a synthetic opioid) and vecuronium bromide. The presence and the size of the VSD were determined by using transesophageal color flow Doppler echocardiography. Four animals showed VSDs of 1-2 mm size. Inhaled NO was then administered with increasing inspired concentrations of 0, 5, 10, 20, 40, 80 and again 0 ppm NO for 10-min periods. NO inhalation did not affect heart rate, right cardiac output, mean arterial pressure, pulmonary arterial wedge pressure, or central venous pressure. Inhaled NO in animals with proven VSDs decreased pulmonary artery pressure (PAP) in a dose dependent manner; 5 ppm NO reduced mean PAP from 25 +/- 2.3 mm Hg to 18 +/- 0.8 mm Hg (p < 0.05), while pulmonary vascular resistance (PVR) decreased from 954 +/- 143 dyn.cm. s-5 to 661 +/- 88 dyn.cm.s-5 (p < 0.01) at the same dose. The maximum reduction in mean PAP and PVR occurred when 80 ppm NO was inhaled. Yucatan micropigs without VSDs did not respond hemodynamically to NO inhalation. Methemoglobin levels remained unchanged during the entire study. Platelet function was assessed according to the method of BREDDIN and BORN (BORN 1962). Initial aggregation and slope were affected when NO inhalation commenced. Yucatan micropigs with VSDs may represent a suitable model for further research of the in vivo effects of inhaled NO.

Administration, Inhalation↗

PubMed1995

Activation of blood coagulation after cardiac arrest is not balanced adequately by activation of endogenous fibrinolysis.

BACKGROUND: Animal studies have demonstrated that hemostatic disorders occurring after cardiac arrest affect outcome. We investigated hemostatic changes during and after cardiopulmonary resuscitation (CPR) in humans. METHODS AND RESULTS: The prospective study included 23 patients (29 to 86 years) who underwent out-of-hospital CPR for nontraumatic causes. Blood samples were drawn immediately and 15 and 30 minutes after initiation of CPR. In the case of restoration of spontaneous circulation (ROSC; n = 7), additional blood samples were taken immediately, 30 minutes, and 2, 8, 24, 48, and 72 hours after ROSC. A marked activation of blood coagulation was found in all patients. The specific markers of activated blood coagulation and fibrin formation, thrombin-antithrombin complex (TAT; median during CPR, 260 micrograms/L; median after ROSC, 57 micrograms/L; normal range, 1.0 to 4.1 micrograms/L), and fibrin monomers (FM; median during CPR, 34.3 micrograms/mL; median after ROSC, 65.4 micrograms/mL; normal range, 0 to 3.6 micrograms/mL) were markedly increased during and in the early phase after CPR. When patients survived for 48 hours, TAT and FM values returned to the normal range. In most patients, the plasma levels of D-dimer, an indicator of endogenous fibrinolytic activity, were not markedly increased during CPR (median, < 0.25 microgram/mL; normal range, < 0.25 microgram/mL) but increased moderately after ROSC (median, 0.56 microgram/mL). Levels of plasminogen activator inhibitor type 1 (normal range, 0.3 to 3.5 U/mL), a marker for endogenous inhibition of fibrinolytic activity, were moderately increased in most patients (median during CPR, 4.22 U/mL; median after ROSC, 8.08 U/mL). CONCLUSIONS: Our data clearly demonstrate that there is a marked activation of blood coagulation and fibrin formation after prolonged cardiac arrest and CPR in humans that is not balanced adequately by concomitant activation of endogenous fibrinolysis. These changes may contribute to reperfusion disorders, such as the cerebral "no-reflow" phenomenon, by inducing fibrin deposition and formation of microthrombi.

Adult↗

PubMed1995

Recovery characteristics following anaesthesia with sevoflurane or propofol in adults undergoing out-patient surgery.

The aim of the study was to compare recovery characteristics in adult patients following general anaesthesia either with the new investigational volatile agent sevoflurane or with propofol. Accordingly, two groups of 25 adults undergoing outpatient surgery were entered into a prospective, randomised study. Patients who received sevoflurane were extubated at an earlier stage than those receiving propofol (6.6 vs. 9.8 min), and the times to eye opening (7.2 vs. 12.6 min) and hand squeezing (8.2 vs 13.8 min) were also shorter. As measured by the digit-symbol substitution test, patients regained the pre-operative level of cognitive function significantly earlier after sevoflurane anaesthesia. Modified Aldrete scores were also higher in this group within the first hour after anaesthesia than in the propofol group. Sevoflurane appears to be a useful alternative to propofol in outpatient anaesthesia.

Adult↗

PubMed1995

Continuous versus intermittent cardiac output measurement in cardiac surgical patients undergoing hypothermic cardiopulmonary bypass.

OBJECTIVE: Continuous thermodilution cardiac output (CCO) measurement was clinically evaluated in patients who underwent coronary revascularization using hypothermic low-flow, low-pressure cardiopulmonary bypass (CPB). DESIGN: Prospective study. SETTING: University hospital setting. PARTICIPANTS: 30 cardiac surgical patients. INTERVENTIONS: CCO was correlated to standard bolus thermodilution cardiac output (ICO) obtained at end-expiration. MEASUREMENTS AND MAIN RESULTS: Measurements were taken at selected time points (n = 18) before anesthesia induction, before CPB, and 5 minutes to 12 hours after CPB. A total of 540 data pairs were thus obtained. ICO ranged from 1.9 to 9.9 L/min, CCO from 1.5 to 9.9 L/min. Correlation between ICO and CCO was highly significant (r = 0.872; p < 0.01), accompanied by an excellent accuracy (bias -0.0213 L) and precision (0.59 L) before CPB and more than 45 minutes after CPB. However, during the first 45 minutes after CPB, there was no correlation (r = 0.273) between ICO and CCO, and ICO tended to be relatively high, whereas CCO measurements showed relatively low values. During the first 45 minutes after hypothermic CPB, but not during the ensuing time period, central blood temperature decreased, which may be interpreted as a lack of thermal equilibration between central and peripheral compartments. It is hypothesized that thermal instability in combination with increased respiratory variations in pulmonary artery blood temperature caused inhomogenous rewarming of different body sites and might be the main reason for the lack of correlation between ICO and CCO. CONCLUSIONS: Despite an excellent correlation, accuracy, and precision between CCO and ICO before CPB and more than 45 minutes after hypothermic CPB, a lack of correlation in the early phase after CPB has been found. Further investigation is needed to elucidate the underlying cause of these findings and to clarify whether ICO or CCO or both fail to represent the real cardiac output up to 45 minutes after weaning from hypothermic CPB.

Adult↗

PubMed1995

[Thrombomodulin as endothelial cell marker in heart surgery patients].

OBJECTIVE: Thrombomodulin is a high-affinity receptor for thrombin on the endothelial cell surface. The aim of our study was to investigate whether plasma thrombomodulin represents a marker of endothelial injury following cardiopulmonary bypass. METHODS: Plasma levels of thrombomodulin were quantitated in 70 plasma samples obtained from 14 adult cardiac patients undergoing hypothermic pulsatile low-flow low-pressure cardiopulmonary bypass. Blood samples were taken before cardiopulmonary bypass (T1), and 15 minutes (T2), 1 hour, 6 hours, and 20 hours after termination of bypass. Plasma thrombomodulin was quantitated with a sandwich enzyme-linked immunosorbent assay (ELISA). Statistical analysis was performed by the Friedman and Wilcoxon tests. RESULTS: Plasma thrombomodulin was significantly elevated 20 hours after discontinuation of cardiopulmonary bypass, when compared with T1 and T2. CONCLUSION: We conclude from our results that a moderate elevation of plasma thrombomodulin is seen in adult patients following hypothermic, low-flow low-pressure cardiopulmonary bypass, which may reflect endothelial injury. Circulating thrombomodulin levels are thus possibly useful for assessment of endothelial damage occurring in patients undergoing cardiopulmonary bypass.

Adult↗

PubMed1995

Gastric tonometry: effect of sucralfate on calculated intramural pH.

Tonometric measurement of gastric intramural pH (pHi) is a noninvasive method to assess adequacy of splanchnic perfusion. Calculation of pHi may be influenced by various factors. This prospective study was designed to determine if stress ulcer prophylaxis with sucralfate interferes with pHi measurement. Twenty-five adult patients admitted to the intensive care unit (ICU) after open heart surgery were studied. Nasogastric tonometers were placed. Patients received sucralfate 1 g via the nasogastric tube 8 hours after termination of surgery, thereafter every 6 hrs. Gastric luminal pH and intramural pH were determined immediately prior and 1 hour after the first sucralfate administration. Gastric intramural pH was calculated from the arterial HCO3- concentration and the tonometrically determined intraluminal PCO2 value using the Henderson-Hasselbalch equation. Intraluminal PCO2(ss) was measured to 6.86 +/- 0.75 kPa prior to sucralfate administration as compared to 6.96 +/- 0.68 kPa 1 hour after 1 g sucralfate (P = 0.92). Intramural pH, as calculated by tonometry, was 7.31 +/- 0.05 vs 7.31 +/- 0.05, and was thus not influenced by sucralfate administration (P = 0.97). Mean gastric intraluminal juice pH was 4.2 +/- 1.3 compared to 4.2 +/- 1.2 (P = 0.59). These data suggest that sucralfate does not interfere with tonometrically determined intraluminal PCO2 measurement and calculation of gastric intramural pH.

Aged↗

PubMed1995

Dose-response, time-course of action and recovery of rocuronium bromide in children during halothane anaesthesia.

Two groups of children, aged 1-4 years (n = 28) and 5-10 years (n = 28), respectively, received at random one of four doses of rocuronium (0.12, 0.17, 0.22 or 0.27 mg kg-1). When maximum block was obtained, further rocuronium to a total dose of 0.5 mg kg-1 was given. At a spontaneous T1 recovery of 25% the block was reversed with atropine and neostigmine in half the patients. The remainder were allowed to recover spontaneously. There was no difference in potency in the two age groups. An ED50 of 0.2 mg kg-1 was estimated. The estimates of ED50 were model-dependent of approximately 0.32 mg kg-1. The maximum block was found significantly higher in the younger age group (99.0 +/- 1.5% (mean +/- SD)) as compared to the older group (97.5 +/- 2.3%), and the clinical duration was also longer (16.6 +/- 5.3 min vs. 13.3 +/- 3.8 min), respectively. There was no significant difference between the two age groups in duration90 (26.9 +/- 6.5 min, 22.5 +/- 6.7 min, respectively) and duration0.7 (27.6 +/- 6.0 min, 24.9 +/- 7.9 min, respectively). Recovery time25-75, recovery time25-90, but not recovery time25-0.7 were found significantly longer in the 1-4 year group as compared to the times in older children. Neostigmine administration reduced recovery time by approximately half to two-thirds. MAP was not influenced by rocuronium. Following the injection of rocuronium in the younger age group there was a 15% increase in heart rate compared to a 10% increase in the age group 5-10 years.

Androstanols↗

PubMed1994

Bolus injection of thrombolytic agents during cardiopulmonary resuscitation for massive pulmonary embolism.

Thrombolytic therapy has proved to be efficacious in the treatment of massive and fulminant pulmonary embolism (PE), but thrombolysis has been considered as contraindicated during cardiopulmonary resuscitation (CPR). This review on the administration of thrombolytic agents in patients who have suffered massive PE necessitating CPR summarises 14 anecdotal reports and three case series involving 34 patients. The case series revealed an overall initial survival rate of 55-100% following bolus administration of thrombolytic agents. In general, bleeding complications were managed conservatively. The establishment of the diagnosis may be feasible using echocardiography or bedside angiography during CPR. However, therapeutic measures should be taken without delay; the patient's history and the clinical picture may thus be the only diagnostic criteria. Even where myocardial infarction is misinterpreted as PE during CPR, bolus injection of a thrombolytic agent can be an appropriate therapeutic option. An alternative may be mechanical catheter fragmentation of the thrombus with subsequent local thrombolysis. Surgery may be restricted to hospitals with ready access to extracorporeal circulation. We conclude that early administration of thrombolytic agents during PE necessitating CPR may help to reduce mortality. We favour the administration of urokinase (2- to 3,000,000-U bolus) or rt-PA.

Adult↗

PubMed1994

[In vitro study of the formation of NO2 in inhalation of nitrogen monoxide].

OBJECTIVE: Nitric oxide (NO), an endogenous endothelium-derived relaxing factor, produces profound relaxation of vascular smooth muscle. Thus, inhaled NO is a potent and selective pulmonary vasodilator that may be useful for treatment of pulmonary hypertension of different aetiologies. However, the main danger of NO inhalation is spontaneous formation of toxic nitrogen dioxide (NO2) if NO is added to an oxygen-containing gas mixture. This chemical reaction depends on the time available for the oxidation and the concentration of NO and oxygen. The aim of this study was to assess in vitro the spontaneous formation of NO2 during administration of various NO concentrations with a ventilator. A modified ventilator system is described which can deliver NO within clinically relevant concentrations avoiding excessive formation of toxic NO2. METHODS: The system was evaluated using an artificial lung. NO and NO2 concentrations were measured by chemiluminescence at the proximal and distal end of the inspiratory limb. In-vitro NO2 formation was assessed during administration of 10, 20, 40, 80 ppm NO while ventilating with an FiO2 of 0.25, 0.5 and 0.75, an inspiratory minute volume of 5, 7.5 and 10 l/min (IMV) and a respiratory rate of 12/min. RESULTS: NO2 concentration correlated with increasing FiO2 and NO concentration and was inversely correlated to IMV. While ventilating with 5-40 ppm NO, an FiO2 of 0.25-0.75 and an IMV of 10 l per minute, the NO2 formation was measured to be less than 0.2 ppm and thus not clinically relevant. During administration of 80 ppm NO the NO2 formation increased to 0.3-0.6 ppm. CONCLUSION: We conclude that for patients safety concentrations less than 80 ppm of inhaled NO should be used with this ventilator system. In addition, online monitoring of the NO2 concentration in the inspiratory limb should always be performed.

Artificial Organs↗