Search PubMed⌕ Search

Biomedical subjects

A Rieger

Publications and source records attributed to A Rieger.

At least 55 records · Page 3Linked to original sources
PubMed1997

Laryngo-pharyngeal complaints following laryngeal mask airway and endotracheal intubation.

STUDY OBJECTIVE: To investigate the incidence and severity of laryngo-pharyngeal complaints following anesthesia with the use of a laryngeal mask airway (LMA) compared with endotracheal intubation in adults. DESIGN: Prospective study with randomized patient selection. SETTING: University medical center. PATIENTS: 202 adult ASA physical status I, II, and III patients scheduled for elective surgery of either an extremity or breast, or a transurethral resection. INTERVENTIONS: Following intravenous induction of anesthesia, a standard LMA size #3, #4, or #5 corresponding to the patient's body weight, was inserted in 103 patients; 99 patients were intubated with a polyvinylchloride endotracheal tube [7.5 mm inner diameter (ID) in women and 8.0 mm ID in men]. Cuff pressures in the LMA group were initially reduced to a minimum pressure at which an air-tight seal between the LMA and the laryngeal inlet was provided at a positive pressure of 20 cm H2O during manual bag ventilation. Cuffs of endotracheal tubes were inflated and controlled to a volume needed to prevent gas leak at 35 cm H2O pressure. MEASUREMENTS AND MAIN RESULTS: Cuff pressures were continuously monitored in both groups. Patients assessed their laryngo-pharyngeal complaints on a 101-point numerical rating scale on the evening after surgery and the following two days. No difference was found in the incidence and severity of sore throat on the evening following surgery or on the two following days. Dysphonia was more frequent following intubation than following LMA insertion on the day of surgery (46.8% vs. 25.3%) and on the first postoperative day (28.1% vs. 11.6%) (p < 0.05). However, the incidence of dysphonia increased with the duration of anesthesia in LMA patients but not in intubated patients. The incidence of dysphagia was significantly higher following LMA insertion compared with endotracheal intubation on the day of surgery (23.8% vs. 12.5%), and on the first postoperative day (22.3% vs. 10.4%). The severity of the individual complaints of minor laryngo-pharyngeal morbidity was comparable between groups. The type of airway management during anesthesia did not affect patient satisfaction with the anesthesia received. CONCLUSIONS: There is a distinct pattern of laryngo-pharyngeal complaints following the use of the LMA and endotracheal intubation. With regard to minor laryngo-pharyngeal morbidity, the advantage of the LMA to endotracheal intubation is questionable.

Deglutition Disorders↗
PubMed1997

Dorsal spondylodesis of unstable thoracolumbar fractures by a far-lateral approach to the disc.

This paper describes a modified and less traumatic approach to the thoracolumbar spine and compares it with standard techniques for instrumented spinal fusion. Ten patients with unstable fractures of the thoracolumbar spine were included in the open prospective investigation, and were treated by a surgical technique consisting of a dorsolateral approach to the injured segment, filling the disk space and the fractured vertebra with autologous bone, and transpedicular fixation with an AO internal fixator. All patients were followed for 6 to 12 months after surgery by clinical tests and spinal X-rays. Excellent short-term and long-term results were obtained. A stable bony fusion was achieved in all cases, and a minimal mean decrease of 2 degrees in the kyphosis angle was found at late follow-up. No major complications related to the procedure were encountered, and no worsening of neurological deficits occurred after surgery. In conclusion, the far-lateral approach to the thoracolumbar spine yields results which are equivalent or better than those of standard techniques. Major advantages of our procedure, as evaluated in this rather small group of patients, are selective immobilization of the injured segment without involvement of functionally intact spinal levels, no manipulations within the spinal canal boundaries, and relatively limited exposure of the spine.

Adult↗
PubMed1997

Intracuff pressures do not predict laryngopharyngeal discomfort after use of the laryngeal mask airway.

BACKGROUND: The laryngeal mask airway (LMA) is a large foreign body that exerts pressure on the pharyngeal mucosa, which may lead to throat discomfort. To determine whether intracuff pressures are associated with such discomfort, a randomized, double-blind study was performed to determine the effect of high versus low intracuff pressures. METHODS: Seventy healthy women were randomly allocated to two groups with different LMA intracuff pressures: 30 mmHg (low pressure) or 180 mmHg (high pressure). Pressures were controlled with a microprocessor-controlled monitor. Insertion of the LMA was performed by one investigator and facilitated with propofol and verified fiberoptically. Anesthesia was maintained with enflurane and nitrous oxide. The LMAs were removed while the patients were still asleep. Patients assessed their laryngopharyngeal complaints (sore throat, dysphagia, hoarseness) at 8, 24, and 48 h after operation on a 101-point numerical rating scale. RESULTS: No significant difference was found in the overall incidence of complaints between both groups (low pressure: 50%; high pressure: 42%). On the day of surgery, dysphagia (38%) was more frequent than sore throat (16%) or hoarseness (6%) (P < 0.05) within the high-pressure group. In the low-pressure group, the incidence of these complaints was not significantly different (33%, 20%, and 23%, respectively). On the following day, dysphagia was still present in 20% of the women in both groups, and other symptoms comprised 10% or less of the reported complaints. CONCLUSIONS: Differences in LMA intracuff pressures did not influence either the incidence or severity of laryngopharyngeal complaints.

Adult↗
PubMed1997

Continuous monitoring of the partial pressure of oxygen in cerebral venous blood.

OBJECTIVE: Clinical oxygen monitoring in the injured brain is somewhat difficult. However, ischemia is one of the major factors responsible for secondary tissue damage after head injury or subarachnoid hemorrhage. Therefore, the aim of the present study was to investigate the value of continuously monitoring the partial pressure of oxygen in cerebral venous blood (PcvO2) during changes in intracranial pressure (ICP). METHODS: In eight domestic pigs with Clark type probes placed in the posterior third of the superior sagittal sinus, PcvO2 was continuously registered while ICP was stepwise elevated by an inflatable balloon placed below the tentorium. Arterial blood pressure was continuously monitored, cerebral perfusion pressure (CPP) was calculated, and arterial partial carbon dioxide pressure and partial pressure of oxygen were registered intermittently. RESULTS: The mean intraparenchymal ICP before the start of balloon inflation was 5 +/- 1 mm Hg, the mean CPP was 80 +/- 15 mm Hg, and the mean PcvO2 was 36 +/- 3 mm Hg. At maximum ICP elevation, CPP decreased to 20 +/- 12 mm Hg, PcvO2 decreased to 10 +/- 6 mm Hg, and ICP increased to 90 +/- 10 mm Hg. Strong linear correlations between ICP and PcvO2 and between CPP and PcvO2 were revealed, and mean correlation coefficients of 0.89 for ICP/PcvO2 and 0.73 for CPP/PcvO2 were calculated. CONCLUSION: The present study demonstrates that polarographic PcvO2 monitoring in the superior sagittal sinus is a reliable method for the early detection of reduced CPP during ICP elevation. This technique is capable of registering the global oxygen supply and oxygen consumption of the brain. It seems superior to jugular venous oxymetry and is better suited for clinical use because of a somewhat low artifact susceptibility.

Animals↗
PubMed1997

Comparison of T2-weighted and fluid-attenuated inversion-recovery fast spin-echo MR sequences in intracerebral AIDS-associated disease.

PURPOSE: To compare the value of fast fluid-attenuated inversion-recovery (FLAIR) with T2-weighted fast spin-echo MR imaging in the detection of acquired immunodeficiency virus (AIDS)-related lesions of the brain. METHODS: Forty-four human immunodeficiency virus (HIV)-positive patients were examined with both sequences on either a 1.0-T or a 1.5-T MR system. The number, size, location, and conspicuity of the lesions were evaluated by two independent observers. Contrast ratios between lesions and normal brain/cerebrospinal fluid were determined, and contrast-to-noise ratios were calculated. RESULTS: FLAIR was found to be superior to T2-weighted fast spin-echo in detection of small lesions and of lesions located in cortical/subcortical regions and deep white matter. The two techniques were equal in delineation of lesions larger than 2 cm and for lesions located in the basal ganglia and posterior fossa. In 24 patients, more lesions were detected with the FLAIR fast spin-echo technique. Lesion/cerebrospinal fluid contrast ratios and contrast-to-noise ratios were significantly higher for the FLAIR fast spin-echo sequences than for the T2-weighted fast spin-echo sequences. CONCLUSION: FLAIR allows early detection of small lesions in subcortical and cortical locations, especially in HIV encephalitis. Because of its improved lesion detection rate and greater overall lesion conspicuity, we believe FLAIR is useful in the evaluation of subtle changes in the brains of AIDS patients with central nervous system disease, and could even replace the T2-weighted fast spin-echo technique.

AIDS Dementia Complex↗
PubMed1997

Comparison between continuous brain tissue measurement and cerebrovenous measurement of pO2, pCO2 and pH in a porcine intracranial pressure model.

Simultaneous oxygen measurements in brain tissue (p(ti)O2) and hemoglobin saturation measurement in cerebrovenous blood in patients after severe head injury have shown different results regarding the comparability of the findings in respect to CPP and ICP. This is contrast to theoretical expectations. The aim of this study was to compare continuous ptiO2 measurement with oxygen partial pressure measurement in sagittal sinus (pO2cv) during simultaneously performance in an animal intracranial pressure model. For continuous measurement we used a newly available multisensor probe. We placed a Paratrend 7 probe (BSL, High Wycombe, UK) in the left frontoparietal white matter and measured ptiO2, pCO2 (ptiCO2) pH (pHti) and temperature (t(ti)) while simultaneously measuring these parameters (pcvO2, pcvCO2, pHcv, tcv) in the sagittal sinus in 9 pigs under general anaesthesia. A fogarty balloon catheter was placed supracerebellar infratentorial and inflated stepwise in order to increase ICP. The baseline levels of pO2ti, pCO2ti und pHti in the non-injured brain tissue showed a more extended heterogeneity compared to the findings in cerebrovenous blood. Both, pO2ti and pO2cv were significant correlated to the CPP decrease. In both measurement compartments pCO2 was inverse correlated to the course of CPP and seems the course of pH mainly to determine. p(ti)O2 as well as p(cv)O2 showed a close correlation to the CPP course and have proven to be qualified to indicate metabolic information about the relation of cerebral blood flow and metabolic cerebral demands. The measurement of CO2 tension in both measurement compartments shows a distinct heterogeneity of the absolute values and the results are only weak correlated to CPP. Metabolic influence on this parameter could not be revealed in the used experimental approach.

Animals↗
PubMed1997

Continuous pO2 and pCO2 measurement in brain tissue and cerebrovenous blood during different inspired oxygen settings. A porcine model.

The clinical use of brain tissue oxygen measurement in patients with severe head injury is increasing. It is important to compare the findings in brain tissue with jugular bulb oximetry, to obtain normal values and to find out limitations of the method. We evaluated a newly available multisensor probe simultaneously in the brain tissue and in the sagittal sinus in a porcine animal model. We placed the Paratrend 7-probe (BSL, High Wycombe, UK) in the left frontoparietal white matter and measured pO2 (ptiO2), pCO2 (pti CO2), pH and temperature while simultaneously measuring these parameters (pcvO2, pcvCO2) in the sagittal sinus in 7 pigs under general anaesthesia during a 100% oxygen enhancement. The relation between oxygen increase in brain tissue and in the sagittal sinus showed a coefficient of correlation (CCmean) r(mean) = 0.96. The quantitative response in brain tissue was much more sensitive than in the sinus. A close correlation between pCO2 in brain tissue and sagittal sinus and the increase of the inspired oxygen was seen: CC ptiCO2 to arterial oxygen pressure (paO2) - r(mean) = 0.67, CC pcvCO2 to paO2 - r(mean) = 0.88. This is important for interpreting measured values and introducing new coefficients for patient monitoring. Newly available continuous brain oxygen measurement methods will allow better understanding of brain metabolism in the future.

Algorithms↗
PubMed1996

Intercurrent complications in chronic alcoholic men admitted to the intensive care unit following trauma.

OBJECTIVE: A chronic alcoholic group following trauma was investigated to determine whether their ICU stay was longer than that of a non-alcoholic group and whether their intercurrent complication rate was increased. DESIGN: Prospective study. SETTING: An intensive care unit. PATIENTS: A total of 102 polytraumatized patients were transferred to the ICU after admission to the emergency room and after surgical treatment. Of these patients 69 were chronic alcoholics and 33 were allocated to the non-alcoholic group. The chronic-alcoholic group. met the DSM-III-R and ICD-10 criteria for alcohol dependence or chronic alcohol abuse/harmful use. The daily ethanol intake in these patients was > or = 60 g. Diagnostic indicators included an alcoholism-related questionnaire (CAGE), conventional laboratory markers and carbohydrate-deficient transferrin. MEASUREMENT AND RESULTS: Major intercurrent complications such as alcohol withdrawal syndrome (AWS), pneumonia, cardiac complications and bleeding disorders were documented and defined according to internationally accepted criteria. Patients did not differ significantly between groups regarding age, TRISS and APACHE score on admission. The rate of major intercurrent complications was 196% in the chronic alcoholic vs 70% in the non-alcoholic group (p = 0.0001). Because of the increased intercurrent complication rate, the ICU stay was significantly prolonged in the chronic-alcoholic group by a median period of 9 days. CONCLUSIONS: Chronic alcoholics are reported to have an increased risk of morbidity and mortality. However, to our knowledge, nothing is known about the morbidity and mortality of chronic alcoholics in intensive care units following trauma. Since chronic alcoholics in the ICU develop more major complications with a significantly prolonged ICU stay following trauma than non-alcoholics, it seems reasonable to intensify research to identify chronic alcoholics and to prevent alcohol-related complications.

Adolescent↗
PubMed1996

[Intraoperative airway obstruction during use of a laryngeal mask. A case report and fiber optic findings].

Laryngeal obstruction is a challenging complication during anaesthesia with a face mask or laryngeal mask and is due to insufficient analgesia in most cases. However, with a laryngeal mask in place it must be differentiated whether the airway obstruction is caused by the laryngeal mask itself or by other factors. Knowledge of the pathophysiology of the laryngeal closure and experience with the use of the laryngeal mask are essential for adequate treatment. Not the removal of a correctly inserted laryngeal mask which initially provided a satisfying airway, but the relaxation of laryngeal muscle activity by adequate anaesthesia is the first mandatory treatment if intraoperative airway obstruction occurs.

Adult↗
PubMed1996

A comparison of sevoflurane with halothane in outpatient adenotomy in children with mild upper respiratory tract infections.

STUDY OBJECTIVE: To investigate the efficacy and safety of sevoflurane compared with halothane in pediatric outpatient ear-nose-throat (ENT) surgery during the induction, maintenance, emergence, and recovery of anesthesia. DESIGN: Prospective, randomized, comparative, open-label study. SETTING: ENT operating room and postoperative recovery room at a university medical center. PATIENTS: 41 ASA status I and II children between the ages of 2 to 10 years, with mild upper respiratory tract infection (URI). INTERVENTIONS: Induction and maintenance of anesthesia with either sevoflurane or halothane for outpatient adenotomy, otomicroscopy, and myringotomy. MEASUREMENTS AND MAIN RESULTS: Induction (means +/- SEM) was significantly shorter in the sevoflurane group (2.6 +/- 0.2 minutes) than in the halothane group (3.2 +/- 0.2 minutes). There was no difference between the two groups with regard to complications that occurred during the induction and maintenance period. The time to emergence and recovery was significantly shorter with sevoflurane than with halothane (means +/- SEM; time to extubation 9.9 +/- 0.98 minutes vs. 13.4 +/- 1.06 minutes, time to eye opening 12.9 +/- 1.6 minutes vs. 24.5 +/- 1.8 minutes, command response time 20.7 +/- 2.5 minutes vs. 36.4 +/- 2.8 minutes). No difference in the incidence of complications during emergence and recovery was found. Evaluation of recovery as assessed by a modified Aldrete score showed that children who had received sevoflurane reached higher scores in the first 30 minutes following the discontinuation of the anesthetic. The Pain/Discomfort Scale demonstrated a difference in the sevoflurane group, with more children being agitated and restless. CONCLUSION: Sevoflurane provides a safe and rapid anesthetic induction with no differences in complications during the induction, maintenance, and emergence period. With sevoflurane, the time of emergence and recovery was significantly shorter. The characteristics of sevoflurane as evaluated in the present study make it a suitable anesthetic in pediatric outpatient surgery even in the presence of mild URI.

Adenoids↗
PubMed1996

Marked increases in heart rate associated with sevoflurane but not with halothane following suxamethonium administration in children.

The changes in heart rate and arterial blood pressure following the administration of suxamethonium in healthy children (mean age 3.8 +/- 0.3 years) during inhalational induction with either sevoflurane (n = 22) or halothane (n = 19) were studied. Heart rate 60s following suxamethonium administration increased significantly in the sevoflurane but not in the halothane group. In the halothane group, four children required intravenous (i.v.) atropine as as result of bradycardia. None of the children in the sevoflurane group developed bradycardia following suxamethonium (P < 0.05). Values of oxygenation, ventilation and age corrected minimal alveolar concentration were comparable at all measurement times. The haemodynamic response to the administration of suxamethonium in children anaesthetized with sevoflurane seems to reflect the stimulation of the autonomic ganglia by suxamethonium whereas this positive chronotropic effect is attenuated or reversed by halothane.

Anesthetics, Inhalation↗
PubMed1996

[Intubation trauma of the larynx--a literature review with special reference to arytenoid cartilage dislocation].

Trauma to the cricoarytenoid joint represents a rare but serious complication of endotracheal intubation. Subluxation and luxation of the arytenoid cartilage may occur during difficult but also following uncomplicated intubation. Forces on the arytenoid cartilage exerted by the laryngoscope blade or by the distal part of the endotracheal tube may cause anterior and inferior displacement of the arytenoid cartilage. Due to the conventional intubation technique the left arytenoid cartilage is affected most frequently. Posterolateral subluxation is attributed to the pressure exerted on the posterior glottis by the convex part of the shaft of the tube. Systemic diseases (e.g. terminal renal insufficiency, bowel diseases, acromegaly) may cause degeneration of the cricoarytenoid ligaments, thus making the cricoarytenoid joint more susceptible to traumatic dislocation. Persisting alterations of voice, sore throat and pain on swallowing may hint to the diagnosis of arytenoid dislocation. However, stridor and shortness of breath have also been observed. If pharyngo-laryngeal complaints persist, evaluation by laryngologists is mandatory. In addition to indirect and direct laryngoscopy, computerised tomography and electromyography of the larynx play an important role in differentiating arytenoid dislocation from true vocal cord paralysis due to nerve damage. Early operative reposition results in fair prognosis, whereas delayed diagnosis may lead to ankylosis of the cricoarytenoid joint with permanent impairment of the voice and possibly compromised airway protection.

Anesthesia, Endotracheal↗
PubMed1996

Ultrasound-guided endoscopic fenestration of the third ventricular floor for non-communicating hydrocephalus.

Conventional valve shunting for treatment of hydrocephalus has a high rate of long-term complications. Endoscopic ventriculostomy by fenestration of the third ventricular floor, a minimally-invasive technique, avoids many of the drawbacks of extracranial shunting. Endoscopy was performed in 12 hydrocephalic patients with MRI-diagnosed aqueductal stenosis and neurological signs. Intraoperative ultrasound guidance allowed aiming the tip of the rigid endoscope to the foramen of Monro, and direct entering of the enlarged third ventricle. This technique is as exact as stereotaxy but is faster and easier. No complications were seen due to the surgical procedure. Nine patients were cured from their complaints, in 3 cases there was a subjective improvement of neurology. Long-term patency of the third ventriculostomy was confirmed by movement-sensitive MRI.

Adult↗
PubMed1996

Patient-controlled intranasal analgesia: a method for noninvasive postoperative pain management.

Recently, a new device for patient-controlled intranasal analgesia (PCINA) was described, and a pilot study demonstrated promising results with respect to efficacy and patient satisfaction. The present study compares PCINA with intravenous (IV) patient-controlled analgesia (PCA). Fifty orthopedic patients were prospectively studied over an 8-h period on the first day after surgery. The patients were randomly allocated to PCINA group (n = 25) or to an IV PCA group (n = 25). Pain intensity was evaluated at 30-min intervals using a 101-point numerical rating scale. With respect to initial pain intensity, there was no significant intergroup difference. At the 30- to 480-min measurement points pain intensity in the PCINA group (P < 0.0001) and the IV PCA group (P < 0.0001) was significantly less as compared to the initial value. There was no significant intergroup difference in pain intensity. No patient had problems using the PCINA device. The present study demonstrates, that PCINA provides relief of postoperative pain as effectively as IV PCA.

Administration, Intranasal↗
PubMed1996

Dysregulation of the polymorphonuclear leukocyte--Candida spp. interaction in HIV-positive patients.

OBJECTIVE: In HIV-infected patients there is an increased frequency of fungal infections. Dysregulation of the response of phagocytic cells to fungal pathogens may be involved. DESIGN: Phagocytosis of Candida spp., consecutive intracellular production of reactive oxygen species, and candicidal activity were analysed in polymorphonuclear leukocytes (PML) from HIV-1-infected patients, who were at stage C3 of the 1993 revised Centers for Disease Control and Prevention classification system, by means of flow cytometry. METHODS: Phagocytic ability was assessed by measuring uptake of fluorescein isothiocyanate-labelled Candida albicans, C. krusei and C. glabrata. Reactive oxygen intermediate production was estimated by the quantity of dihydrorhodamine-123 converted to rhodamine-123 intracellularly. The candicidal effect was assessed by the propidium iodide uptake of killed yeast cells. RESULTS: As compared to PML of healthy, HIV-negative controls, PML of AIDS patients exhibited an increased phagocytic activity and a similar ability to generate reactive oxygen products. In contrast, PML of AIDS patients displayed a decreased candicidal activity (P < 0.05 compared to controls). CONCLUSION: These results suggest that in patients with advanced HIV-1 infection the impairment of non-oxidative killing mechanisms of phagocytic cells may contribute to the high incidence of fungal infections.

Adolescent↗
PubMed1996

Specific hepatitis B virus minus-strand DNA synthesis requires only the 5' encapsidation signal and the 3'-proximal direct repeat DR1.

Human hepatitis B virus (HBV) is a small DNA virus that replicates inside the viral nucleocapsid by reverse transcription of an RNA intermediate, the pregenome. The sequences encompassing the encapsidation signal epsilon and the direct repeat DR1 are present in two copies of this terminally redundant transcript. We have recently shown that HBV minus-strand DNA synthesis involves transfer of a short DNA primer copied from 5'-epsilon to 3'-DR1 (DR1*). Using transfection of HBV genomes with lesions in 3'-epsilon, and 5'-DR1 and its preceding sequence, we tested whether these additional elements contribute to the specificity of the transfer reaction. However, while some mutations affected proper plus-strand DNA formation, 5'-epsilon and DR1* were completely sufficient for correct minus-strand DNA production.

Base Sequence↗