[Organizing and equipping the workplace].
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Anesthesia Department, Hospital↗
Biomedical subjects
W Dick
Publications and source records attributed to W Dick.
[A universally applicable mask attachment for fiberoptic intubation. The Mainz Universal Adapter].
The problems associated with "difficult airways" have almost subsided since the introduction of flexible fiberoptic bronchoscopes for tracheal intubation. Limitations of this technique persist with uncooperative patients, children and infants. We describe an universally applicable connector for fiberoptic intubation during mask ventilation, which fits all masks with a 22-mm connector, including the Rendell-Baker-Soucek type. This technique is of utmost value when a "difficult airway" is encountered only subsequent to induction of anesthesia, especially if nondepolarizing muscle relaxants have been administered. The device makes intubation possible with all sizes of fiberoptic bronchoscopes. The prerequisites for application of this technique include an airway that will be maintained by mask ventilation.
Adolescent↗
[Early defibrillation in the emergency doctor rendezvous system].
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Electric Countershock↗
Failure of opioids to affect excitation and contraction in isolated ventricular heart muscle.
The opioid agonists morphine (selective for mu-receptors) and ethylketocyclazocine (selective for kappa-receptors), at concentrations evoking strong effects in neuronal structures, did not significantly affect the configuration of the intracellularly recorded action potential and the force of contraction in ventricular heart muscle isolated from guinea pigs, rabbits and man. These results suggest that any changes of heart functions in vivo in response to opioid-like drugs are probably not mediated postsynaptically at the myocardial cell membrane but rather presynaptically, influencing the release of noradrenaline and/or acetylcholine from the nerve terminals.
Acetylcholine↗
Accuracy of delivered versus preset minute ventilation of portable emergency ventilators.
The accuracy of delivered minute volume (VE) ventilation of portable emergency ventilators (PEV) was evaluated. Five PEV from three manufacturers were adapted to an artificial lung for varying compliance and resistance. Each PEV was tested in the "no airmix" (pure oxygen) and "airmix" (approximately 60% oxygen) setting at different frequencies and VE. Measurement of delivered VE (VEdel) was made using a pneumotachograph and digital integration of the flow values greater than 1 min (maximal error +/- 2%). Maximal inspiratory pressure (Pinsp) was measured with a transducer. Two PEV from one manufacturer produced severe hyperventilation when used at low VE (i.e., in children). Two other PEV from another manufacturer produced less marked hyperventilation, but revealed unexpected hypoventilation during conditions of higher inspiratory pressures (i.e., in adults with reduced compliance). The prototype PEV that was tested also revealed less marked hyperventilation with small decreases (down to -10% of the VE at higher Pinsp values). Further investigation is needed before this prototype goes into production. Manufacturers should redefine predicted values or machine settings or indicate that use of these devices may produce results which are not in accordance with the machine settings. Until adjustments are made, ventilation should be monitored when possible by measurement of end-tidal PCO2 or systemic arterial blood gases.
Adult↗
Induction potency of various beta-lactam derivatives in gram-negative rods.
The induction potency of various beta-lactams as well as that of 'nonspecific' inducers such as the media employed or body fluids were studied in gram-negative clinical isolates and in their resistant corresponding counterparts. In all wild-type isolates quite a few beta-lactams (mainly cefoxitin and imipenem) shared the ability to induce the chromosomal beta-lactamase, whereas all beta-lactams - including 6-APS and 7-CPS clavulanic acid, and sulbactam (both beta-lactamase inhibitors), exhibited strong induction potency in their corresponding resistant counterparts. Moreover, all resistant counterparts exhibited the phenomenon of 'nonspecific' induction, whereas the wild-type strains did not. Interestingly, in both Proteus vulgaris 4917 W and Providencia rettgeri 862 W wild-type strains most beta-lactam compounds were potent inducers, thus providing an explanation for resistance against beta-lactamase-unstable compounds. The addition of subinhibitory concentrations of the quinolone compound enoxacin or chloramphenicol did not influence the phenotypic beta-lactamase expression, neither in wild-type strains nor in their resistant counterparts, whereas the addition of clindamycin or gentamicin resulted in a marked decrease of enzyme production in cephalosporinase overproducers, the P. vulgaris and the P. rettgeri isolates.
Anti-Bacterial Agents↗
Arterial and mixed venous blood gas status during apnoea of intubation--proof of the Christiansen-Douglas-Haldane effect in vivo.
The Christiansen-Douglas-Haldane effect, in short the Haldane effect, describes the dependence of the CO2 binding of blood on the degree of oxygenation of haemoglobin. Under the physiological conditions of an 'open' system between blood and alveoli the partial pressure of arterial CO2 (PaCO2), must be less than that of mixed venous blood (PvCO2). During the unphysiological conditions of a 'closed' system, e.g. hyperoxic apnoea, i.e. continuous oxygen uptake without CO2 delivery by the lungs, the PaCO2 will not only approximate the PvCO2 but will even exceed it. Without the Haldane effect, rapid adjustment of PaCO2 to PvCO2 would be expected during apnoea due to the lack of CO2 excretion. If, however, as undertaken in this study, ongoing oxygenation (high alveolar PO2 (PACO2) with concomitant lack of CO2 delivery (apnoea, i.e. the CO2 concentration remains constant) lead to a continuing sufficient oxygenation of blood during its passage through the lung capillaries, then this leads to a rightwards shift of the CO2 binding curve--the Haldane effect. The resulting increase in PCO2 as shown here actually leads to an arterial-mixed venous CO2 partial pressure difference (avDPCO2) of 2.8 +/- 1.8 mmHg. The results described substantiate for the first time the existence of the Haldane effect under clinical conditions.
Apnea↗
[The status of arterial and mixed venous blood gases in the initial phase of intubation apnea. Studies on the Christiansen-Douglas-Haldane effect].
The Christiansen-Douglas-Haldane effect describes the reduced CO2 binding capacity of oxygenated as compared to deoxygenated hemoglobin on the basis of its increased acidity. This study describes the development of the above effect during the first 2 min of hyperoxic intubation apnea. METHODS. After institutional approval 12 patients (NYHA III, ASA IV) scheduled for coronary-artery bypass grafting were studied after written informed consent. Routine monitoring measures included invasive arterial and pulmonary-arterial pressure monitoring. Pulse oximetry (Nellcor N 101) was also used during intubation apnea. Premedication consisted of flunitrazepam 2.0 mg p.o. the evening before operation and another 2.0 mg p.o. 90-120 min before induction of anesthesia. Following standardized preoxygenation induction of anesthesia was performed with 20-25 micrograms/kg fentanyl and 0.1 mg/kg pancuronium. After cessation of spontaneous respiration, controlled ventilation was continued with 100% oxygen until intubation. Thirteen arterial (a) and mixed-venous (v) blood samples were drawn sequentially immediately before and during the first 2 min of apnea and analyzed using Corning 150 pH/blood gas analyzer and a Corning 2500 CO-oximeter. RESULTS. As shown in Table 1 and Fig. 1, paO2 decreased from 485 +/- 100 mmHg before apnea to 376 +/- 68 mmHg after 2 min of apnea while pvO2 remained constant at 47-50 mmHg. Arterial oxygen saturation (saO2) showed stable values greater than 97% while svO2 slightly increased from 81.9% to 82.4% until the end of apnea. A biphasic increase was observed in paCO2 from 41.2 +/- 3.4 mmHg before to 54.5 +/- 3.9 mmHg at the end of apnea. An increase in pvO2 during apnea was linear from 45.7 +/- 3.9 mmHg to 51.9 +/- 4.0 mmHg. After 28.5 s of apnea paCO2 exceeded pvCO2 due to the Haldane effect ("pCO2 reversal"). During apnea, pHa decreased biphasically from 7.40 +/- 0.03 to 7.31 +/- 0.02. The speed of decrease was 0.106 pH units/min (5-35 s) in the 1st and 0.023 pH units/min in the 2nd min of apnea; pHv decreased almost linearly from 7.37 +/- 0.03 mmHg (5s) to 7.33 +/- 0.02 mmHg (115s). After 20.66 s of apnea pHa exceeded pHv ("pH reversal"); pH-reversal occurred earlier than pCO2 reversal (p less than = 0.05). CONCLUSIONS. During early hyperoxic apnea, venoarterial pH and pCO2 reversal can be observed due to the Christiansen-Douglas-Haldane effect. pH reversal starts earlier than pCO2 reversal. Reversal time is dependent on arterial-mixed-venous pCO2 difference (avDpCO2) before apnea, arterial-mixed-venous O2 saturation difference (avDsO2) and cardiac output. The amount of reversal is dependent on avDsO2, i.e. the pH difference of arterial and m
Aged↗
[Fentanyl versus sufentanil basic anesthesia. Hypnotic effect, muscle rigidity and efficacy of competitive muscle relaxants].
As induction agents for cardioanesthesia, sufentanil (S) and fentanyl (F) are usually employed in combination with nondepolarizing muscle relaxants. We investigated potential interactions of these opioids with the relaxant component, paying special regard to the role of muscular rigidity and opioid-induced alterations of hemodynamics. Narcotic anesthesia was induced randomly in 45 coronary artery bypass patients with either F (20 micrograms/kg) or S (4 micrograms/kg). After 6 min, neuromuscular blockade was initiated within each group randomly with either vecuronium (V) or pancuronium (P) (0.01 mg/kg each). During opiate administration, the times for cessation of spontaneous respiration and loss of responsiveness to verbal and tactile stimuli were measured. The degree of opiate-induced muscular rigidity, simultaneous changes in arterial paCO2, cardiac indices (CI) prior to opioid and relaxant administration, onset and recovery from neuromuscular blockade (by electromyographic train-of-four registration), and motor response to laryngoscopy and intubation were recorded. The onset of spontaneous apnea (TK = time to breathing upon command only) and unresponsiveness (TM = time to controlled mask ventilation) was significantly faster with S than with F. Muscular rigidity was moderate in 25% of patients and severe in 35%-40%, during the administration of both narcotics. No significant differences between S and F were observed. During ventilation by face mask, patients with clinically apparent rigidity showed a statistically significant mean increase in paCO2.(ABSTRACT TRUNCATED AT 250 WORDS)
Anesthetics↗
[Sufentanil: the effect on cardiocirculatory parameters and intubation conditions on administration of pancuronium or vecuronium].
A lack of uniform methodology used in the assessment of moderate doses of sufentanil in combination with non-depolarizing neuromuscular blocking drugs formed the basis of the current study which compared under randomized conditions the effects of sufentanil-pancuronium versus sufentanil-vecuronium on hemodynamics, intubating conditions and chest wall rigidity during induction of anesthesia. MATERIAL and METHODS. One hundred and twenty ASA physical status I and II patients aged between 20 and 40 years of age who were undergoing elective urological surgery were included in the study. Premedication consisted of 0.15 mg kg-1 diazepam, given orally 60 min prior to induction of anesthesia. Patients were randomly divided into eight groups of 15 each to receive 0.5 microgram kg-1 sufentanil or placebo in combination with pancuronium (groups I-IV) or vecuronium (groups V-VIII) Within each group, patients were randomly allocated to receive the relaxant either as a single bolus dose of 0.095 mg kg-1 pancuronium or 0.1 mg kg-1 vecuronium, or in divided doses (the priming principle), the smaller priming dose (0.015 mg kg-1 pancuronium or 0.015 mg kg-1 vecuronium) being administered 2 min before induction of anesthesia with 5 mg kg-1 thiopentone, followed by the second intubating dose of 0.080 mg kg-1 pancuronium or 0.085 mg kg-1 vecuronium. To maintain blind study conditions in the groups, the patients given the relaxants in one dose were given an equivalent volume of saline 2 min prior before 5 mg kg-1 thiopentone. Intubating was attempted 60 s after administration of the main dose of the relaxant, and conditions were assessed on a four-point scale: excellent, satisfactory, fair, or poor. Neuromuscular transmission was monitored with the Datex Relaxograph, a neuromuscular transmission analyzer, that utilizes the integration of the EMG response. Producing train-of-four (TOF) stimuli, with a pulse width of 100 microseconds and a frequency of 2 Hz every 20 s the following parameters were recorded by the Datex Relaxograph: The percentage of first twitch amplitude compared with the reference (T1), and the train-of-four (TOF) ratio, i.e., the ratio of last twitch height to first height. Measurements were taken after premedication in the operating room, the value which served as a baseline (t0), 1 min after sufentanil or placebo (t1), 1 min after priming or placebo (t2), 1 min after thiopentone (t3), and 1 min after intubation (t4).(ABSTRACT TRUNCATED AT 400 WORDS)
Adult↗
Effects of different glucose concentrations on spinal anaesthesia with bupivacaine and tetracaine.
The effects of 5% and 8% glucose in 0.5% tetracaine or bupivacaine on the anaesthetic spread were investigated in 80 urological patients requiring spinal anaesthesia for trans-urethral resection of the prostate. The local anaesthetic solutions were randomly administered, the patients being divided into four groups of 20, and the anaesthetic profile was then evaluated in a double-blind fashion by an independent observer. Maximum cephalad spread of analgesia was significantly greater with tetracaine in 8% glucose compared to the other three groups (tetracaine/5% glucose, bupivacaine/5 or 8% glucose) (P less than 0.05). Glucose concentration significantly influenced spreading characteristics of tetracaine, the 8% solution achieving a higher level in a shorter time than the 5% solution. Sensory regression to both T10 and S1 dermatome was longer with bupivacaine in 8% glucose compared to 5% glucose. The concentration of glucose, however, did not influence the regression of sensory analgesia for tetracaine. Both the 5% and 8% solutions of tetracaine achieved a 3+ motor blockade significantly faster than either bupivacaine solution. Regression of motor blockade from tetracaine was not influenced by the glucose concentration, but the 8% solution of bupivacaine had a delayed 2+ and 3+ blockade, although the ultimate decay for both solutions was similar. The results of our study suggest that 0.5% bupivacaine 4 ml in 5% glucose provides a rapid and controllable spread of sensory analgesia for transurethral surgery, of optimal duration associated with a complete motor blockade of moderate duration.
Aged↗
[The effect of the injection speed on the blockade characteristics of hyperbaric bupivacaine and tetracaine in spinal anesthesia].
A lack of uniform methodology used in the assessment of different injection speeds in spinal anesthesia by different authors formed the basis of the current study, which compared under randomized conditions the effects of various injection speeds during intrathecal administration of 4 ml 0.5% hyperbaric bupivacaine or 0.5% hyperbaric tetracaine. MATERIALS AND METHODS. Eighty male ASA Physical Status II and III patients scheduled for transurethral resection of the prostate under spinal anesthesia were selected. They were randomly divided into four groups of 20 each. Patients were given 4 ml of either 0.5% hyperbaric bupivacaine or 0.5% hyperbaric tetracaine according to the following scheme: I: 4 ml tetracaine/0.25 ml.s-1; II: 4 ml tetracaine/0.5 ml.s-1: III: 4 ml bupivacaine/0.25 ml.s-1; IV: 4 ml bupivacaine/0.5 ml.s-1. The study was carried out in a double-blind fashion and puncture was performed at the L3-4 interspace using a 25-gauge needle with the patient in the sitting position. Following injection of the anesthetic solution (0.25 ml.s-1 or 0.5 ml.s-1 without barbotage), the patient was immediately placed in the lithotomy position with the table remaining horizontal. The level of anesthesia using pin prick and the degree of motor blockade, using a 0 to 3+ scale where 0 represented no motor weakness and 3+ complete motor block, were assessed at specific intervals. Statistical analysis was performed using the Mann-Whitney rank sum test: P value of less than 0.05 was considered statistically significant. RESULTS. Bupivacaine injected at 0.25 ml.s-1 was associated with a higher dermatome level than at 0.5 ml.s-1 (P less than 0.05). Time to highest dermatome, however, was shorter with bupivacaine 0.5 ml.s-1 compared to 0.25 ml.s-1 (P less than 0.05) (Table 3, Fig. 1). Time to highest level of analgesia was shorter with tetracaine 0.25 ml.s-1 compared to 0.5 ml.s-1 (P less than 0.05) (Fig. 2). At 0.25 ml.s-1, tetracaine achieved the highest dermatome faster than bupivacaine (P less than 0.05). Tetracaine injected at 0.5 ml.s-1, however, was associated with a higher segmental level than bupivacaine (P less than 0.05). At 0.25 ml.s-1 bupivacaine and tetracaine achieved a 3+ motor block faster than at 0.5 ml.s-1 (P less than 0.05). Complete motor blockade, however, was significantly longer with tetracaine at both injection speeds (0.25 and 0.5 ml.s-1) compared to bupivacaine (P less than 0.05). CONCLUSIONS. The results suggest that 4 ml 0.5% hyperbaric bupivacaine or tetracaine injected at 0.25 or 0.5 ml.s-1 provides a rapid and reproducible spread of analgesia for transurethral surgery. However, our findings suggest that speed of injection is of little i
Aged↗
[Cooperation between obstetrics and anesthesia. II. From the viewpoint of anesthesiology].
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Anesthesia, Obstetrical↗
[The Oxytron: a new device for administering oxygen in the spontaneously breathing patient].
The Oxytron (Weinmann, Hamburg, FRG) electronic oxygen conserver (patent pending) is a new device designed to deliver precise amounts of oxygen at the optimum point in the breathing cycle via a nasal cannula. In 200 Oxytron the delivered volume of oxygen was 35 +/- 5 ml within 150-200 ms at the beginning of the inspiratory phase of the respiratory cycle. Four different settings are possible: setting 1 provides one insufflation every 4th breath; setting 2 provides one insufflation every 2nd breath; setting 3 provides three insufflations every 4 breaths; and setting 4 provides an insufflation with every breath. These settings provide approx. The equivalent of 1-4 l oxygen per minute on a continuous flow basis. Both clinical experience and literature reports show variations in savings, with an average ratio of approx. 6:1 to 7:1. In the clinical evaluation, the following advantages were found: easy handling, exact oxygen delivery, increased oxygen saving and increased oxygen delivery with increasing respiratory rate. Due to the lack of any alarm system monitoring disconnection or failure of oxygen supply must be considered a disadvantage.
Anesthesia↗
[The washout behavior of isoflurane following balanced anesthesia and its effect on postoperative oxygen supply].
Few studies have described the pharmacokinetics and pharmacodynamics of isoflurane (I) during the postoperative recovery room stay. In this study the influence of balanced anesthesia with I on the postoperative course was investigated by studying pulmonary washout of I and its effect on arterial oxygen saturation. METHODS. Following institutional approval and informed consent, 50 patients (ASA I and II) scheduled for lateral fenestration for intervertebral disc herniation participated; all had no previous record of cardiopulmonary problems. Induction of anesthesia was achieved with intravenous alcuronium 0.03 mg/kg, fentanyl 0.003 mg/kg, thiopental 5 mg/kg, and succinylcholine 1.5 mg/kg followed by alcuronium 0.09 mg/kg before changing to the prone position. Anesthesia was maintained with controlled ventilation in a rebreathing system (fresh gas flow FGF) = 3.01/min, FIO2 = 0.3 in N2O, plus 0.8 Vol.-% cIet = 1.3 MAC). Near the end of surgery I was discontinued and IGI was increased to 61/min O2 for 10 min. Patients then returned to breathing ambient air. Extubation was carried out as soon as a minimum tidal volume of 400 ml was obtained. End tidal I concentration (cIet; Vol.-%) was measured by infrared absorption (Normac, Datex) and O2 saturation by pulse oximetry (Biox III, Ohmeda). Datum point of the pulmonary I-washout curve was the mean end-tidal I concentration obtained 15 min before terminating I (cIAW). Effects of duration of anesthesia, Broca index, and amount of I administered (tidal volume x inspiratory I concentration x min; ml) on I-washout were assessed. A pulse-oximetric O2 saturation of less than 90% was regarded as hypoxygenation. RESULTS. Mean duration of anesthesia for both males and females was 85 +/- 25 min, mean Broca index 102 +/- 13. The amount of I administered with the inspiratory volume was 5.661 +/- 2.194 1 I (1.0 +/- 0.4 Vol.-%). Mean I-regression (Fig. 3) was 236 x 10(-5) Vol.-%/min (Figs. 1 and 3). Mean I-washout 60 min after extubation was 44.6 +/- 15.2% of the administered amount. Adequate spontaneous breathing began a mean of 17 min after the end of I exposure, corresponding to 20% cIet of washout. All patients were extubated after a mean of 22 min at a mean etI of 17% of washout. After extubation, pulse oximetry indicated hypoxygenation in 18 patients (= 36%) during 2 periods (Fig. 4): (1) at a mean cIet of 0.1 Vol.-% (= 15% of washout) after a mean of 8 min; and (2) at a mean cIet of 0.08 Vol.-% (= 12% of washout) a mean of 19 min following extubation. Further episodes of hypoxygenation occurred as much as 40 min post-extubation. (ABSTRACT TRUNCATED AT 400 WORDS)
Adult↗
[Revision arthroplasty of the hip joint with autologous and homologous cancellous bone].
On revision arthroplasty a substantial loss of bone stock is frequently encountered. To anchor the new prosthesis many different additional technical appliances, e.g. supporting rings, wire meshes and fixation screws, are suggested. However, filling of all the bone cavities by cement will lead to further peripheral defects of bone stock, worsening the situation if renewed loosening occurs. Such loosening must be expected since additional bone is damaged by the implants and the large amount of cement. Therefore, it is increasingly recognized that biologic reconstruction of the deficient acetabulum and femoral shaft by bone grafting should be the goal in revision arthroplasty, in order to restore the bone-implant interface to the site of a primary arthroplasty. Autologous bone graft is harvested from the outer iliac wing as a bone paste most easily by use of an acetabular reamer. As an additional approach is needed and the amount is not always sufficient, often homologous bone is used in solid cortico-cancellous blocks or as a bone paste ground by a bone mill. The bone banking procedure is described. At the acetabulum the grafting technique depends on whether there is a contained or non-contained defect. The cup has to be brought to the anatomical position and should be supported at several sites by the original iliac bone and not only by the graft. At the shaft, osteotomy of the greater trochanter can be avoided by a lateral transgluteal approach in the vast majority of cases (90 out of 95 cases). If still possible, a short stem is preferred to an extra-long one. Follow-up examination of 164 patients at 46 months (min. 24, max. 78 months) after cup revision showed that 8 re-revisions had been performed in the meantime: in 6 cases renewed loosening or infection had been treated by implantation of a new component; in 2 cases a Girdlestone procedure was the final outcome.
Acetabulum↗
[Monitoring critically ill patients during transport by helicopter using a patient with abdomen apertum as an example].
Noninvasive continuous monitoring systems are newly emerging as an important means of monitoring during transports in emergency care, e.g. transportation by helicopter. While automatic oscillometric blood pressure monitors have been used in the perioperative area for some time, a similar development can be observed in the field of emergency care and transportation with the availability of light, portable and battery operated systems. For monitoring adequate oxygenation, pulse oximeters have recently been brought into discussion for both the perioperative period and the transport of critically ill patients. In contrast to well-established monitoring techniques during helicopter transports (ECG, inspection, manually measured blood pressure (BP), pulse oximetry reveals an oxygen deficiency due to respiratory and cardiocirculatory problems, enabling precious time to be saved. This concept is illustrated during the helicopter transport of a critically ill patient with abdomen apertum caused by Clostridium perfringens infection. Even with a critical look at the already described mishaps of this method--e.g. overestimation of true O2 saturation (sO2) and additional overestimation caused by Hb-derivatives--pulse oximetry was found to be superior to the established monitoring techniques. Furthermore, oscillometric blood pressure detection was very satisfactory during the 30-min helicopter transport. Based on our results, we believe pulse oximetry and automatic oscillometric BP-measurement to be useful for monitoring during transports in helicopters, thus improving patient safety.
Abdomen↗
[Controversial aspects of the mechanisms for maintaining blood flow in cardiopulmonary resuscitation].
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Heart Arrest↗