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Biomedical subjects

W Dick

Publications and source records attributed to W Dick.

At least 109 records · Page 6Linked to original sources
PubMed1994

[Perioperative complications in HIV-positive patients].

In a retrospective study, the perioperative findings and complications of AIDS patients and asymptomatic HIV-positive patients were compared to those of HIV-negative patients. Characteristic operations in HIV-positive patients were those of extremities in general surgery, and dilatation and curettage in gynecology. There were significant differences among three groups concerning preoperative hemoglobin, GOT, electrolyte concentrations and heart rate. As the preoperative findings, hepatitis and dyspnea on exertion were remarkable in the HIV-positive patients. During anesthesia tachycardia was more frequent in the HIV-positive patients. Postoperatively high fever, anemia and tachycardia were significantly more frequent in the HIV-positive patients. The postoperative leucocyte count was less in the AIDS-patients than in other two groups. As a whole there are some peculiarities about the estimation of the risk and the planning of anesthesia in the HIV-positive patients.

Acquired Immunodeficiency Syndrome↗
PubMed1993

Residual intersegmental spinal mobility following limited pedicle fixation of thoracolumbar spine fractures with the fixateur interne.

The Fixateur Interne has been proposed for limited pedicle fixation of thoracolumbar spine fractures with the assumption that motion in the nontraumatized spinal segments could be maintained. To date, no data exist that both localize and quantitate spinal mobility about the fractured vertebra. Voluntary maximum lateral flexion and extension radiographs were obtained on patients with unstable thoracolumbar spine fractures at a minimum of 2 years after Fixateur Interne instrumentation (implant was removed after 1 year). Residual intersegmental motion was measured at levels adjacent to both the vertebra fracture and the fixation. Fifty-nine patients were reviewed, and the posterior vertebral body angle demonstrated a mean total sagittal motion of 2.98 degrees. Cephalad and caudal to the fractured vertebra, a mean of 1.34 degrees and 3.08 degrees, respectively, of residual motion was noted; cephalad and caudal to the previously instrumented segment a mean of 3.22 degrees and 6.88 degrees, respectively, was measured. The authors conclude that residual mobility is most evident at the caudal end of the instrumented segment, removed from the fractured vertebra. The level with end plate disruption becomes essentially ankylosed, with or without a fusion.

Adolescent↗
PubMed1993

The effect of the type of colloid on the efficacy of hypertonic saline colloid mixtures in hemorrhagic shock: dextran versus hydroxyethyl starch.

Colloids increase and prolong the efficacy of hypertonic saline solutions in hemorrhagic shock. We compared the efficacy of dextran 60 and hydroxyethyl starch (HES) 200,000/0.5 at iso-oncotic concentrations of 6.5 or 6% in a 7.5% NaCI solution. Thirty-two rabbits were bled to maintain a mean arterial pressure at 35 mmHg. Twenty-five percent of the shed blood volume was replaced after 40 min by bolus infusion either with hypertonic dextran (HS-DEX) (n = 16) or with hypertonic hydroxyethyl starch (HS-HES) (n = 16). The animals were then observed for a 120-min period. In both groups immediate and complete restoration of cardiovascular function was achieved in up to 30 min and adequate restoration maintained for 60 min after infusion. During the subsequent 60 min signs of insufficient oxygen supply indicated the recurrence of near shock levels. Greater stability of hemodynamic efficacy was observed when dextran was added to hypertonic saline. The decrease in mean arterial pressure was lower in the dextran group (P < 0.05). The subsequent increase in avDO2 (v. cava sup.) was approximately 50% lower with dextran (1 ml/dl compared to 1.8 ml/dl); (P < 0.05). These differences occurred primarily within the initial 15 min although the differences in mean arterial pressure were recorded only after 30-60 min. A 50% reduction in lactate levels (1.1 compared to 2.0 mmol; P < 0.05) in immediate response to reinfusion indicates an increased lactate absorption and thus improved perfusion of poorly perfused tissue in the dextran group. A further, important difference may be due to the different effects on the microcirculation. As evidenced by a decline in the end-expiratory arterial CO2 gradient, dextran effected a significant (P < 0.01) improvement in decreased pulmonary CO2 emission during shock. This indicates a greater rise of blood flow in poorly perfused, ventilated pulmonary areas. In summary, in our model dextran appeared to be the superior colloid compared to HES, particularly during the first hour after initiation of treatment, although direct proof of an improved long term outcome has not been demonstrated.

Acidosis↗
PubMed1993

Metabolism of the herbicide atrazine by Rhodococcus strains.

Rhodococcus strains were screened for their ability to degrade the herbicide atrazine. Only rhodococci that degrade the herbicide EPTC (s-ethyl-dipropylthiocarbamate) metabolized atrazine. Rhodococcus strain TE1 metabolized atrazine under aerobic conditions to produce deethyl- and deisopropylatrazine, which were not degraded further and which accumulated in the incubation medium. The bacterium also metabolized the other s-triazine herbicides propazine, simazine, and cyanazine. The N dealkylation of triazine herbicides by Rhodococcus strain TE1 was associated with a 77-kb plasmid previously shown to be required for EPTC degradation.

Atrazine↗
PubMed1993

[Fiberoptic intubation in the prone position. Anesthesia in a thoraco-abdominal knife stab wound].

An ambulance was dispatched to a 40-year-old man with a stab wound. On arrival, the emergency physician found the patient lying face down with a large knife protruding from his back between the scapula and spinal column (Fig. 1). The vital signs were stable (blood pressure 120/70 mmHg, heart rate 90 min, respiratory rate 25-30 min, oxygen saturation 94%); the estimated blood loss was 500 ml. Oxygen was administered and two i.v. lines were inserted. After light sedation (diazepam), the patient was transported to the clinic in the face-down position. X-ray films and physical examination showed that the knife, with a length of about 30 cm, had penetrated 15 cm into the thorax; the tip was located at the diaphragm (Fig. 2). Endotracheal intubation for the surgical revision was performed with the patient in the face-down position: after topical anaesthesia of the nasal mucosa (cocaine), a fiberoptic device was introduced. Additional topical anaesthetic (lignocaine) was applied through the biopsy channel onto the mucosa of the larynx and pharynx. After a sufficient waiting period, the endotracheal tube was pushed over the fiberoptic device into the trachea without problems (Fig. 3). During the entire period the patient was awake and breathing spontaneously; no coughing or change of body position occurred. After correct placement of the tube, general anaesthesia was induced. During positioning of the patient in the operating theatre, the knife was unintentionally dislodged and critical bleeding occurred. The situation could be controlled by immediate transfusions and rapid surgical revision, which revealed injuries to the lung, diaphragm, and stomach. The patient recovered without severe complications.(ABSTRACT TRUNCATED AT 250 WORDS)

Abdominal Injuries↗
PubMed1993

[The preclinical efficacy of emergency care. A prospective study].

Quality assurance has become an important issue in emergency medicine. At present, no prospective studies are available that quantify the efficacy of interventions performed by emergency doctors. The development and implementation of a rapid, yet simple scoring system, allowing preclinical assessment of all emergency medicine patients, is required. Once the scoring system is implemented, evaluation of the prehospital intervention, based upon objective parameters, is possible. METHODS. The Mainz Emergency Evaluation Score (MEES) is based on seven parameters: level of consciousness, heart rate, heart rhythm, arterial blood pressure, respiratory rate, partial arterial oxygen saturation and pain. A coded value is assigned to each parameter, with the normal physiological condition securing a score of 4, while a life-threatening condition receives a value of 1. For the parameter of pain there is no life-threatening condition, so the lowest value allowed is 2 (Table 2). Addition of the respective values from the seven parameters yields the MEES value, which objectively reflects the patients' condition (minimum = 8, maximum = 28). Comparing the MEES value before (MEES1) and after the intervention (MEES2) allows an objective evaluation of the efficacy of the preclinical care (delta-MEES = MEES2-MEES1). A difference of > or = +2 is considered an improvement, +1, +/- 0, -1 are rated as unchanged and < or = -2 is considered a deterioration in the patients condition. For more detailed evaluation the patients were allocated to 16 diagnosis groups (Table 3). Statistical evaluation utilized analysis of variance, the rank sum test (Wilcoxon) and the correlation coefficient (Kendall-Tau). RESULTS. In 356 patients the condition of 187 (52%) patients improved during the preclinical treatment; the condition of 156 (44%) patients did not change. In 13 patients (3%) the condition became worse (Table 5, Fig. 2). Allocation to 16 diagnosis groups revealed that the improvement in the patient's condition depended on the underlying disease (Table 3); the disease-specific parameter improved in all cases (Table 7). CONCLUSIONS. With the MEES score one can assess the patient's prehospital condition and monitor any improvement or deterioration during subsequent intervention and transport. The MEES was found to be easy to use, reliable and not an additional burden to emergency doctors. The MEES provides a means of assessing the efficacy of preclinical treatment. This score does not allow outcome prediction; this requires the inclusion of hospital data. Assessment of the efficacy of prehospital intervention is an important first step in the inclusion of quality assurance in emergency medical systems.

Emergency Medical Services↗
PubMed1993

[Intraoperative cardiopulmonary disorders during esophagectomy in relation to the surgical technique].

Twenty-one healthy female sheep were anaesthetised in a standard technique with ketamine, dehydrobenzperidol and etomidate. In seven sheep an endoscopic esophagectomy was made (group 1), in seven a blunt esophagectomy (group 2) and in a further seven a thoraco-abdominal esophagectomy (group 3). ECG monitoring, invasive blood pressure measurement, measurement of the central venous pressure and the pulmonary artery pressure with estimation of cardiac output, arterial and mixed venous blood gas analyses were made. The measurement times were: ZDM 1 = preoperative, ZDM 2 = after laparotomy, ZDM 3 = after cervical esophagus preparation or thoracotomy, ZDM 4 = after esophagectomy, ZDM 5 = after inflation of the lungs and ZDM 6 = after a second exploration of the esophagus bed (only groups 1 and 2). Finally the sheep in groups 1 and 2 were thoracotomised on the right side. In group 1 the measurement parameters remained largely unchanged during the entire experiment. In group 2 significant and by the end of the operation irreversible pathological changes occurred immediately after the blunt esophagus resection (ZDM 4): decrease of MAP, paO2 and CO, increase of AaDO2 and PVR. In group 3 similar changes were observed, they began, however, during ZDM 3. The measurement results can be explained in accordance with the operative anatomical findings. How far postoperative pulmonary complications can be avoided in patients with the endoscopic technique must be demonstrated in clinical use.

Animals↗
PubMed1993

[Degenerative lumbar scoliosis and spinal stenosis].

Of the types of degenerative lumbar spine deformities, the combination of scoliosis and spinal stenosis is one of the most disabling and progressive conditions in elderly patients. Therapeutic resignation is frequent. In spite of old age and severe osteoporosis 31 patients were treated operatively by reduction, fusion and decompression. There were 24 good results, 2 fair and one poor result. During the postoperative 30-month follow-up period (1-5 years), 4 patients died from unrelated causes. There were no serious primary complications; 3 patients had a reoperation. All patients were living independently at their homes and had a walking capacity of more than 2 km. The good overall result is attributed to the selection of patients, which is the most important factor for the outcome. Nine criteria for patient selection are listed. In multisegmental lumbar spine fusions in elderly patients, the critical areas are sacral fixation of the implant, a loss of lumbar lordosis and, if the fusion is performed from L2 caudad, vertebrae L1 and T12 being located between the lumbar spondylodesis and the stiff thoracic spine.

Age Factors↗
PubMed1992

Physician and nursing (personnel) requirements for ICUs. Therapeutic Intervention Scoring System (TISS) versus time requirements for patient care--a comparative study in an interdisciplinary surgical intensive care unit.

OBJECTIVE: To measure total physician manoeuvres and total nursing manoeuvres in intensive care patients and to compare the results with calculated personnel requirements on the basis of TISS scores. DESIGN: Open prospective study. SETTING: Sixty-three ICU patients on two consecutive days. MEASUREMENT: 1. Total physician activities (TPM) in minutes/patient-day; total nursing manoeuvres (TNM) in min/patient-day. 2. TISS Calculation of personnel requirements on the basis of both parameters. RESULTS: TPM averaged at 3.9 hours. No fixed correlation was established between TISS and TPM. TNM averaged 1,073 minutes/patient-day and demonstrated a good correlation with TISS. CONCLUSIONS: Physician activities on a surgical ICU averaged 3.9 hours/patient-day. Nursing manoeuvres average 17.9 hours/patient-day. Individual measurements must be made before calculating personnel requirements on the basis of TISS scores.

Adolescent↗
PubMed1992

[Histamine release during induction of combination anesthesia using nalbuphine or fentanyl. Modulation of the reaction by premedication with promethazine/pethidine].

In a controlled clinical trial in patients admitted for general surgery (mainly abdominal and thyroid), histamine release following nalbuphine 1 mg/kg i.v. versus fentanyl 5 micrograms/kg i.v. was studied in the course of an otherwise routine induction with promethazine/pethidine as premedication 30 min before the opioids and alcuronium-flunitrazepam-thiopental 5 min later. Succinylcholine was given before intubation and further analgesia was obtained by repeated administration of either nalbuphine or fentanyl. Plasma histamine levels were measured by a specific fluorometric assay, heart rate and blood pressure were measured for assessing hemodynamics, and clinical signs of anaphylactoid reactions such as skin eruptions and arrhythmias were registered. RESULTS. Nalbuphine and fentanyl both released histamine with an incidence of more than 40%. In addition, nalbuphine potentiated the histamine release evoked by the sequential administration of alcuronium-flunitrazepam-thiopental in one complex of application. The incidence of histamine release in the nalbuphine group was 6/13 = 46%, in the fentanyl group only 1/11 = 9% (chi2 test, P less than 0.05). Furthermore, this study showed high histamine levels after succinylcholine and intubation in a relation to time of administration that suggested histamine release as a stress response to intubation. Finally, the incidence of histamine release after a second injection of the opioids was still 30%. A direct correlation between plasma histamine levels, hemodynamic changes, and skin reactions could not be shown. A detailed causality analysis with histamine release as a contributory determinant showed histamine release less detrimental to hemodynamic stability than the opposite, which had been expected. However, the promethazine administered 30 min before induction of anaesthesia had strong H1- and H2-receptor antagonistic activity and was given with optimum timing for H1- and H2-prophylaxis. CONCLUSION. The study demonstrated that histamine release during anaesthesia and surgery depends strongly on the time sequence of drugs and measures used. Histamine release is not predictable from studies in human volunteers alone; studies in patients have to be added. Histamine release is not always detrimental. H3-receptor-mediated effects after H1- and H2-prophylaxis may help patients to counteract the effects of a series of vasoactive drugs given during induction of anaesthesia.

Adult↗
PubMed1992

[Propofol for sedation during postoperative mechanical ventilation. A comparative study with Lytic Mixture].

Propofol infusion was found to provide excellent sedation and rapid recovery in intensive care. The present study compared Propofol with lytic solution (lytic solution = mixture of 100 mg Pethidine, 50 mg Promethazine and 0.6 mg Dihydroergotamine) during 6 hours of postoperative artificial ventilation. 60 patients after major abdominal surgical procedures were studied with ethical committee approval and informed consent. Patients were randomly allocated to receive either Propofol or lytic solution. We aimed at a sedation level of stage 5 according to the Ramsey score. The mean drug dosages were 3.9 mg/kg/h of Propofol and 4.2 ml/h of lytic solution. Hemodynamic values, blood gases as well as various biochemical measures did not show any difference between the groups. At the end of the sedation period triglyceride concentrations were significantly higher in patients receiving Propofol (166 + 79 mg/dl) compared to the control group (97 + 60 mg/dl). Significant and relevant differences were found for the times of recovery after discontinuation of the sedative. These times were very short in the Propofol group. Furthermore, in view of a longer recovery time after lytic solution in this group the respiratory rate was significantly slower up to the end of the observation period. We conclude that a major advantage of Propofol in the present study was the rapid recovery after 6 hour sedation. Patients gain vigilance rapidly and sufficient spontaneous respiration within minutes. Not at least thanks to these facts patient's safety can be improved in the recovery period.

Abdomen↗
PubMed1992

[Dorsal stabilization of thoracic and lumbar vertebral injuries].

The concept of angle-stable transpedicular screw-rod instrumentation, realized in the different models of internal spine fixators with intrinsic stability, allows secure stabilization of the most unstable fracture patterns, limited-segment fixation and three-dimensional reduction of the fragments. The canal diameter is improved by ligamentotaxis and, if necessary, by hemilaminectomy and fragment impaction. Late collapse of the upper disk space must be anticipated and may lead to some increase in kyphotic deformity. The situations are identified where an additional formal interbody fusion is recommended.

Fracture Fixation, Internal↗
PubMed1992

[Which factors determine the critical hematocrit as an indication for transfusion?].

The question as to what extent the hematocrit (Hct) is a strong indicator for or against the need for transfusion of whole blood or blood products is still controversial. In order to enable the clinician to make a definite decision, a number of aspects have to be taken into consideration. The human organism has only limited oxygen reserves, and these are even more limited under pathological conditions. Oxygen flux - the amount of oxygen transported by the blood in 1 min - is a critical factor in the oxygenation of the human body. Another critical factor is oxygen consumption, which is highly variable depending on the presence of conditions such as rest, shivering, seizures, hypothermia, etc. Furthermore, different organ systems have different oxygen consumption rates. The ratio of oxygen consumption to oxygen flux is referred to as the oxygen extraction rate or oxygen utilization. Under normal conditions oxygen uptake is independent of oxygen flux, and thus independent of blood flow. Under conditions of organ dysfunction, however, oxygen deficiency may be present without being recognized on standard clinical diagnostic parameters. The normal human organism has a number of possibilities to compensate for acute or chronic anemia, i.e., increases in cardiac output, organ perfusion, 2,3-DPG content, a shift in the oxygen dissociation curve, etc. These compensatory mechanisms may, however, be restricted or cease to function under conditions of acute or chronic disease. Arterial and mixed-venous PO2 and oxygen content are some of the parameters used to assess the oxygen reserves available to the organism even under critical conditions. Although oxygen content is the most significant of these parameters, accurate measurement of this parameter remains a problem of laboratory medicine. PVO2 is of only limited importance under conditions of anemia. Minimum oxygen content or minimum oxygen flux values should under no conditions be approximated during anesthesia or intensive care. The critical Hct as an indicator for or against transfusion of blood or blood products is considerably modified by restricted organ function, anesthesia, intensive care treatment, resuscitation, etc.(ABSTRACT TRUNCATED AT 400 WORDS)

Anesthesia↗
PubMed1992

[Atropine in the premedication of patients at risk. Its effect on hemodynamics and salivation during intubation anesthesia using succinylcholine].

Should atropine be administered for premedication? This question continues to be controversial; in particular, the combined administration of atropine and succinylcholine has been investigated with conflicting results by numerous researchers. The present study was carried out to assess the effect of premedication with atropine on hemodynamic variables and salivation in patients assigned to ASA class II and III. METHODS. Eighty ASA class II or III patients received pethidine 1.0 mg/kg and promethazine 0.5 mg/kg i.m. 30 min prior to induction of anesthesia and atropine, either 0.01 mg/kg i.v. 10 min or 0.01 mg/kg i.m. 30 min prior to a standardized anesthetic induction with alcuronium (precurarizing dose), thiopental, and succinylcholine. In the control groups (20 patients each), no atropine was given. Systolic, diastolic, and mean arterial pressures (MAP) were measured. The ECG was monitored for arrhythmias. Salivation was assessed semiquantitatively using swabs positioned within the pharyngeal space. RESULTS. Ten minutes after the administration of atropine i.v., a significant increase in heart rate (HR) was observed; this did not occur within 30 min after administration of atropine i.m. At the time of tracheal intubation, HR was significantly increased in both i.v. atropine risk groups. After atropine i.m., an increase in heart rate during intubation was observed in ASA class II patients only. No increase in heart rate occurred in the control groups during tracheal intubation. Neither i.m. nor i.v. atropine had any significant effect on blood pressure. Arrhythmias occurred in a few cases with both routes of administration; several instances of marked tachycardia were recorded.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

[Post spinal headache. Its incidence following the median and paramedian techniques].

A lack of uniform methodology used by different authors in the assessment of different puncture techniques in spinal anesthesia formed the basis of the current study, which compared under randomized conditions the incidence of post spinal headache after a median or paramedian (lateral) approach. MATERIALS AND METHODS. Two hundred and fifty ASA physical status II and III patients, aged 50-85 years, scheduled for transurethral prostate surgery under spinal anesthesia were investigated. The patients were comparable with regard to weight and height (Table 1). No premedication was given and, 30 min prior to surgery, all patients received normal saline 400-500 ml i.v. The patients were randomly divided into two groups of 125 patients each to receive 4 ml 0.5% bupivacaine in 5% glucose (specific gravity 1.017 at 20 degrees C) using the median or paramedian (lateral) approach according to the following scheme (Table 2): I: 4 ml 0.5% bupivacaine/median approach; II: 4 ml 0.5% bupivacaine/paramedian approach. The study was carried out in a double-blind fashion. Neither the patient nor the investigator evaluating the post spinal headache was aware of which technique had been used. Lumbar puncture was performed by a midline approach at the L3-4 interspace using a 25-gauge (Whitacre) spinal needle with the patient in the sitting position group I. The bevel of the spinal needle was directly laterally, so that the dural fibers that run longitudinally were spread rather than transected. When using the paramedian approach (group II), patients were placed in the flexed lateral decubitus position and the spinal needle inserted 1 cm medial and 1 cm lateral and caudad to the lowest part of the posterior superior iliac spine and then directed medially and cephalad at an angle of 55 degrees into the subarachnoid space. Postoperatively, patients were allowed to move as soon as possible; no prophylactic bed rest was ordered. Starting from the 1st postoperative day, patients were evaluated by an independent observer and asked whether they were suffering from any problems concerning anesthesia. Typical post-puncture headache was defined as invariably bifrontal and occipital, frequently involving the neck and upper shoulders, and being aggravated by the upright position. Statistical analysis of the data was performed using the Mann-Whitney rank-sum test for unpaired samples. A P value of less than 0.05 was considered statistically significant. RESULTS. Twenty-six of 250 patients (10.4%) developed post spinal headaches. Comparing both groups, 11/125 (8.8%) patients in the median group (group I) versus 15/125 (12%) in the paramedian group (group II) had typical post-puncture headaches. Within the group of patients aged 50-60 years, the paramedian approach (group II) showed a significantly higher headache rate compared with group I (P less than 0.05). Neurologic sequelae were not observed; 6 patients received epidural injections of autologous blood while the rest of the patients suffering from post spinal headache were treated conservatively with bed rest, analgesics, and fluids. CONCLUSIONS. The results indicate that the incidence of post spinal headache is higher in younger patients when using the paramedian (lateral) approach. However, our findings suggest that the choice of lumbar puncture technique--median or paramedian--is of little importance in regard to post-puncture headache in elderly patients. The paramedian approach is especially useful when degenerative changes are encountered in the interspinous structures in elderly patients, when an ideal position is difficult to achieve.

Aged↗