Effect of tracheal intubation or laryngeal mask airway insertion on intraocular pressure using balanced anesthesia with sevoflurane and remifentanil.

STUDY OBJECTIVES: To study the effect of tracheal intubation or laryngeal mask airway (LMA) insertion on intraocular pressure (IOP) in strabismus patients undergoing balanced anesthesia with sevoflurane and remifentanil. DESIGN: Open, prospective, randomized study. SETTING: Tertiary care academic medical institution. PATIENTS: 40 adult ASA physical status I and II patients scheduled for elective strabismus surgery. INTERVENTION: Patients were randomized to receive either tracheal intubation or LMA insertion following mask induction with sevoflurane in combination with IV remifentanil. MEASUREMENTS: Intraocular pressure, mean arterial pressure (MAP), and heart rate (HR) were measured before induction, immediately following induction, and after airway insertion. MAIN RESULTS: Intraocular pressure after tracheal intubation or LMA insertion did not differ significantly from preoperative baseline values. Mean arterial pressure and HR did not significantly differ between groups at any time point. CONCLUSIONS: Remifentanil and sevoflurane are not associated with an increase in IOP response during tracheal intubation or LMA insertion above baseline in healthy patients undergoing ophthalmic surgery.

[Noise field findings in 24 patients with coronary heart disease]. / Rauschfeldbefunde bei 24 Patienten mit koronarer Herzkrankheit.

PURPOSE: In earlier studies it was shown that patients with vascular disturbances (e.g. sudden hearing loss) had white-noise field campimetry abnormalities despite normal visual fields. The aim of this study was to clarify whether patients with coronary heart disease (CHD) have such disturbances in the white-noise field campimetry, too. PATIENTS AND METHODS: Twenty-four patients (m:f = 23:1; mean age 58 +/- 9 years) with an angiographically documented CHD and 30 healthy controls (m:f = 29:1; mean age 54 +/- 7 years) were examined. In order to evaluate the morphological and functional ocular status, we examined the following parameters: morphological status, visual acuity, intraocular pressure, perimetry (Tübinger Automatic Perimeter 2000 ct, Oculus) and white-noise field campimetry (Tübinger Electronic Campimeter, Oculus). RESULTS: Fifteen patients had had a cardiac infarction. Twenty-one patients, but only 6 controls had alterations in perilimbal vessels of the conjunctiva and sixteen patients had a tortuousity of retinal vessels. The visual acuity, the intraocular pressure, the cup/disc ratio and the visual fields were within normal ranges. However, twenty patients and 5 controls were abnormal in the white-noise field campimetry. DISCUSSION: Although patients with CHD appeared unaffected in the standard eye examinations, the disturbances in the white-noise field campimetry indicated a functional visual impairment. Together with the changes in the perilimbal vessels of the conjunctiva and the retinal vessels, a disturbed ocular microcirculation as the underlaying cause could be discussed.

[White-noise field campimetry in HIV+ patients]. / Rauschfeldbefunde bei HIV+ Patienten.

PURPOSE: The first morphological changes in eyes with HIV infection are microvascular disease of the retina with cotton-wool spots and microaneurysms. The study was performed to find out if evidence of disturbances of ocular microcirculation can be established by non-invasive methods. PATIENTS AND METHODS: Twenty-seven patients with HIV infection and without opportunistic infections underwent thorough ophthalmologic examination with threshold-oriented, suprathreshold perimetry (TAP 2000 ct, Oculus) and white-noise field campimetry (TEC, Oculus). RESULTS: Visual field examination was normal in 23 out of 27 patients (85%), whereas 4 patients showed relative field defects in at least one eye. In white-noise field campimetry 13 out of 23 perimetrically unaffected patients (56%) perceived scotomas in one or both eyes. These scotomas were not stable. Three of 4 patients with relative scotomas in the visual field had cotton-wool spots in the retina and showed a stable scotoma in campimetry. Visual acuity, IOP, and cup/disc ratio were within normal ranges. CONCLUSION: White-noise field campimetry complements the standard examination of patients with HIV and might be capable of indicating disturbances of ocular microcirculation by a non-invasive method before morphological changes in the retina can be seen.

Quantitative determination of isoflurane enantiomers in blood samples during and after surgery via headspace gas chromatography-mass spectrometry.

The quantitative analysis of the chiral volatile anesthetic isoflurane (1) for biomedical applications by means of enantioselective gas chromatography (mass sensitive detector, selected ion monitoring) was studied. Two methods for the quantification of the enantiomers in blood samples drawn during and after narcosis were compared. Either the isomeric enflurane (2) was selected as an internal standard or a single enantiomer of 1 was used for the standard addition method, an approach referred to as 'enantiomer labeling'. Concentrations up to 0.3 micromol/l of the single enantiomers could be differentiated two days after anesthesia. The presented data imply that the body clearance for (+)-(S)-1 and (-)-(R)-1 proceeds to a measurable degree of enantioselectivity.

[Objective assessment of visual field defects using multifocal electroretinography]. / Objektivierung von Gesichtsfelddefekten mit Hilfe der multifokalen Elektroretinographie.

BACKGROUND: Multifocal electroretinography allows simultaneous recording of 61 focal electroretinographic signals from the retina of the posterior pole. The function of the outer retinal layers can be mapped for a visual field of 30.5 degrees radius. We herein describe the topography of such potentials in patients with hemianopic and concentric visual field defects. SUBJECTS AND METHODS: Six patients with visual field defects caused by chorioretinal and central visual pathways diseases were examined using multifocal ERG. RESULTS: In 30 normal volunteers in the entire 30 degrees visual field clear signals were obtained. In the patients with visual field defects caused by retinal diseases in areas with reduced light sensitivity diminished electroretinographical activity was found. In contrast, in patients with bitemporal hemianopsia due to a chiasmal lesion no correlation between visual field and magnitude of focal ERGs was seen. CONCLUSIONS: In retinal disorders defects in multifocal ERG presented the similar pattern as scotomata in perimetry. The patient with visual field defects due to disturbances in the chiasma exhibited a normal ERG-topography. In patients with visual field defects multifocal ERG supported differentiation of the location of the lesion.

[Technique of selective, controlled retinal fibrinolysis in a model]. / Technik der selektiven, kontrollierten retinalen Fibrinolyse im Modell.

By microcatheterization of the ophthalmic artery it was possible to test a controlled retinal fibrinolysis in the rabbit. Heparin, tolazoline and urokinase were applied through the microcatheter. By continuous administration of highly diluted fluorescein (0.1%), on-line control of the therapeutic effects was available. Treatment was carried out in cycles of enforced perfusion. In 12 main vessel occlusions the rates of flow could nearly be normalized after mobilization of thrombi by combined emergency therapy. An average of 14 cycles of treatment was necessary. The time needed was 40-60 min. With this technique drug therapies of ocular circulation disturbances are testable and controlled emergency treatment of the eye begins to become feasible.