Changes in intraocular pressure during low dose intravenous sedation with propofol before cataract surgery.

AIMS: This study examined the effects on intraocular pressure, pulse rate, and blood pressure of low dose intravenous sedation with propofol. METHODS: Twenty adult patients who were scheduled to undergo cataract surgery were given a single intravenous bolus (0.98 (SEM 0.4) mg/kg) of propofol for sedation before administering the local anaesthetic for cataract surgery. A small intravenous dose of lignocaine was the only other anaesthetic or sedative agent given. The intraocular pressure in the non-surgery eye, the pulse rate, and the blood pressure were measured before and after propofol induction. RESULTS: Compared with the preinduction baseline, there was a 17% to 27% (from 16.2 (0.7) mm Hg to 11.8 (0.7) mm Hg) decrease in intraocular pressure after propofol induction. A significant decrease in intraocular pressure occurred within the first minute and was still evident at 7 minutes when the measurements were stopped. There was also a 7%-12% increase in pulse rate during the first 4 minutes, a 12% decrease in mean systolic blood pressure, and a 7% decrease in mean diastolic blood pressure from baseline after propofol induction. CONCLUSION: A single low dose bolus of propofol used for sedation before cataract surgery caused a moderate reduction in intraocular pressure with minimal, easily managed side effects.

Excitatory effects and electroencephalographic correlation of etomidate, thiopental, methohexital, and propofol.

Excitatory movements have been observed during induction of anesthesia with etomidate, thiopental, methohexital, and propofol. We studied the frequency of these excitatory effects and correlated movements with electroencephalographic (EEG) findings in 67 unpremedicated patients (mean age 66.1 yr, range 45-82 yr). Excitatory effects, including myoclonus, tremor, and dystonic posturing, occurred in 86.6% of patients receiving etomidate; 69.2% of the patient responses were myoclonic. Multiple spikes appeared on the EEG in 22.2% of the etomidate patients. The frequency of excitatory effects was 16.6% after thiopental, 12.5% after methohexital, and 5.5% after propofol. None of the patients receiving thiopental, methohexital, or propofol developed myoclonic or seizure activity. In most patients, the excitatory movements were coincident with the early slow phase of the EEG which corresponds to the beginning of deep anesthesia. We conclude that perhaps caution should be exercised when administering etomidate to patients with a history of seizures as the myoclonic activity is associated with seizure activity. The incidence of excitatory movements after administration of propofol is very low.

An electroencephalographic comparison of effects of propofol and methohexital.

Thirty-eight patients were randomly allocated to receive propofol 1 mg/kg (group A, N = 10), methohexital 0.7 mg/kg (group B, N = 9), propofol 2 mg/kg (group C, N = 10), methohexital 1.5 mg/kg (group D, N = 9). They were all male with a mean age of 65.8 years (range, 46-85) and a mean weight of 76.2 kg (range, 50-109). Patients received no premedication. All drugs were administered as a single i.v. bolus. After baseline EEG recordings were obtained, i.v. bolus doses were given and the recording continued until the patients became fully responsive to verbal commands. The EEGs were visually analyzed and classified into 4 phases: phase 0, the wake physiologic pattern; phase 1, initial changes after i.v. bolus doses; phase 2, state of deep anesthesia; and phase 3, stage of recovery. The main change during phase 1 was increase in the amplitude of the background rhythms. Phase 2 was characterized by theta and delta activity and burst suppression in some patients. During phase 3 beta activity was seen following methohexital. Propofol produced a much deeper level of anesthesia compared to methohexital. The stage of deep anesthesia was prolonged following propofol. The clinical and EEG recoveries were prolonged after induction doses of propofol. The quality of recovery, however, was far superior with propofol. Methohexital produces a "hang over" effect which delays full recovery.

Medical indications and contraindications for eye donation.

Potentially useful and valuable donor-eye tissue is lost because physicians decide erroneously that certain deceased people are not suitable donors. The Indiana Lions Eye Bank Inc. needs and will receive with gratitude any and all donated eyes. Donated ocular tissue can be used for research or teaching, if not for actual transplantation. All deceased people should be regarded as suitable eye donors, except when the cause of death or other factors might pose risks for enucleators themselves.

Thyroid carcinoma.

The mode of presentation, initial findings, treatment, and survival in differentiated thyroid carcinoma were studied in 155 patients. The classic signs, symptoms, and scan findings were present in approximately 70 per cent of the patients, with the remaining 30 per cent displaying unusual manifestations or findings. The effects of neck metastases, extracapsular invasion, and recurrent laryngeal nerve involvement on long-term survival were studied in detail. Prognosis was dependent more on age at initial appearance than any other factor. Patients with prior exposure to radiation had more extensive disease and required more extensive surgery, but they ultimately had the same prognosis for 10-year cure. Treatment of distant metastatic disease by surgery, radioactive iodine, and external radiation resulted in long-term survival in certain cases.

Predicting carcinogenicity of petroleum distillation fractions using a modified Salmonella mutagenicity assay.

The Ames Salmonella/microsomal activation mutagenesis assay has been modified to improve sensitivity and reproducibility to complex mixtures derived from the refining and processing of petroleum. Oil samples were dissolved in cyclohexane and subsequently extracted with dimethyl sulfoxide to produce aqueous compatible solutions which readily interact with tester bacteria. Also, the liver homogenate (S-9) and NADP cofactor concentrations were increased and hamster rather than rat liver S-9 was used. The initial slope of the dose response curve relating mutagenicity (revertants per plate) to the dose of extract added was used as an index of mutagenic activity; this slope was obtained through a computerized curve fitting procedure. The modified assay was used to rank 18 oil samples for mutagenic activity; this ranking correlates highly (r = 0.92) with potency rankings of the same samples previously determined from dermal carcinogenicity bioassays. Sensitivity and reproducibility of the assay are sufficient to permit routine use for detecting potential carcinogenic activity of individual refinery streams and blends which contain components boiling above 500 degrees F.

Use of CT in the evaluation of cochlear otosclerosis.

Otosclerosis (otospongiosis) occurs when the hard endochondral bone of the otic capsule is replaced by spongy vascular foci of haversian bone. Using computed tomography (CT), we studied the ears of 32 selected patients with mixed or sensorineural hearing loss (one patient had normal hearing); 24 were suspected of having otosclerosis. CT proved valuable in detecting cochlear otosclerosis, foci of demineralization, and changes in bony texture and enables the easy recognition of subtle radiographic findings. Our paper also reports the CT findings of temporal bones in osteogenesis imperfecta and Paget disease.

Use of CT in stapedial otosclerosis.

Otosclerosis (otospongiosis) is a primary focal disease of the labyrinthine capsule. The stapes footplate is fixed when the spongiotic focus expands and invades the oval window. Persons with stapedial otosclerosis experience a progressive conductive hearing loss. In many cases, cochlear degeneration is observed, in which a mixed hearing loss occurs. Using computed tomography (CT), we studied the ears of 45 selected patients with conductive or mixed hearing loss. CT proved valuable in determining otosclerotic changes of the oval window and otic capsule. Spongiotic changes of the otic capsule are better appreciated by CT than complex motion tomography. The usefulness of CT in diagnosing other causes of conductive or mixed hearing loss is also described.

The Government acts to prohibit surrogacy arrangements.

KIE: It is anticipated that the British government's Surrogacy Arrangements Bill will be law before the summer recess of Parliament. While not dealing with all issues raised by the Warnock Committee report, the bill responds to a perceived need for swift action because of public concern following the so-called "Baby Cotton" case. Both the advertising of surrogacy services and participation in negotiations regarding surrogacy will be forbidden. The position of physicians remains somewhat unclear. It appears that they may treat a surrogate mother but may not advise or participate in surrogate arrangements.^ieng

A government bill on surrogate motherhood?

KIE: Britain's Department of Health and Social Security (DHSS) seems to have badly miscalculated in discounting the political necessity of immediately introducing legislation to ban surrogate parenthood arrangements. After the birth of a baby in a case involving a financial arrangement among a surrogate mother, an agency, and the natural father and his wife, pressures from the House of Commons and from Prime Minister Thatcher are now forcing the DHSS to find a slot in the legislative timetable that would enable a government bill on the subject to be enacted this year.^ieng