Management of airway difficulties during induction of general anesthesia in an American miniature horse with dwarfism

This report describes previously unreported upper airway abnormalities encountered in a 5-month-old American miniature horse colt presented for elective surgery. Caution should be exercised when administering general anesthesia or heavy sedation to individuals of this breed that present with multiple congenital abnormalities.

Pharmacokinetics and toxic effects of lithium chloride after intravenous adminstration in conscious horses

OBJECTIVE

To determine the pharmacokinetics and toxic effects associated with IV administration of lithium chloride (LiCl) to conscious healthy horses.

ANIMALS

6 healthy Standardbred horses.

PROCEDURE

Twenty 3-mmol boluses of LiCl (0.15 mmol/L) were injected IV at 3-minute intervals (total dose, 60 mmol) during a 1-hour period. Blood samples for measurement of serum lithium concentrations were collected before injection and up to 24 hours after injection. Behavioral and systemic toxic effects of LiCl were also assessed.

RESULTS

Lithium elimination could best be described by a 3-compartment model for 5 of the 6 horses. Mean peak serum concentration was 0.561 mmol/L (range, 0.529 to 0.613 mmol/L), with actual measured mean serum value of 0.575 mmol/L (range, 0.52 to 0.67 mmol/L) at 2.5 minutes after administration of the last bolus. Half-life was 43.5 hours (range, 32 to 84 hours), and after 24 hours, mean serum lithium concentration was 0.13+/-0.05 mmol/L (range, 0.07 to 0.21 mmol/L). The 60-mmol dose of LiCl did not produce significant differences in any measured hematologic or biochemical variables, gastrointestinal motility, or ECG variables evaluated during the study period.

CONCLUSIONS AND CLINICAL RELEVANCE

Distribution of lithium best fit a 3-compartment model, and clearance of the electrolyte was slow. Healthy horses remained unaffected by LiCl at doses that exceeded those required for determination of cardiac output. Peak serum concentrations were less than steady-state serum concentrations that reportedly cause toxic effects in other species.

Quality of consumer drug information provided by four Web sites

The quality of drug-specific information available to consumers on the Internet was studied. The 30 most commonly dispensed prescription drugs were selected to represent those medications for which consumers would be seeking information. A Web page evaluation form was developed to objectively evaluate each site in terms of sponsors, references, recency of updates, ease of use, overall organization, and other characteristics. A second form was developed to qualitatively and quantitatively assess the drug information provided by the sites. Four Internet sites, MedicineNet, RxList, Drug InfoNet, and thriveonline, were evaluated. Authors, contributors, and references were identified for three of the sites. All sites had disclaimers advising patients to seek the advice of a health care professional, all indexed drug information by both brand name and generic name, and all were well organized. Only RxList and MedicineNet contained information on all the drugs evaluated. For the drugs documented, RxList, MedicineNet, Drug InfoNet, and thriveonline contained 84%, 60%, 87%, and 72% of the 22 variables assessed, respectively. The accuracy of the information provided was greater than 98% for all the sites. Only two of four Internet sites containing consumer drug information included all the prescription drugs being evaluated. Most but not all of the information on the four sites was accurate.

Vestibular rehabilitation with graded occupations

These three case reports are examples of the use of graded, purposeful activities in remediating the symptoms of vestibular disorders. Therapists can design individualized treatment plans for each patient by incorporating activities of interest to the patient. The treatment activities must include the particular head movements and positions that elicit vertigo during assessment. Additionally, activities must be interesting to the individual patient. Use of interesting activities may sustain the patient's interest and motivation for the treatment program and enable the patient to relate the learning process to real life experience. The principle that graded, repetitive head movement exercise is efficacious in reducing vertigo and disequilibrium in patients with vestibular disorders is now well accepted among physicians and therapists who treat these patients. The principle of adding meaning or purpose to otherwise rote exercise is well accepted among occupational therapists and is supported by evidence from the empirical literature (Heck, 1988; Kircher, 1984; Yoder, Nelson, & Smith, 1989). This concept of adding purpose to repetitive exercise may now be extended to the treatment of patients with peripheral vestibular disorders.

Occupation and visual/vestibular interaction in vestibular rehabilitation

Otolaryngologists often prescribe head movement exercise programs for patients with vestibular disorders, although the effectiveness of these programs and the critical features of the exercises are poorly understood. Because many patients who dislike exercising do not follow through with their exercises, alternatives to the traditional repetitive exercises would be useful. Subjects diagnosed with vestibular disorders were treated for 6 weeks with either an outpatient exercise program that incorporated interesting, purposeful activities or a simple home program of head movements, comparable with the exercises otolaryngologists often give their patients when they do not refer to rehabilitation. Both treatments incorporated repetitive head movements in all planes in space, graduated in size and speed. Subjects were all tested before and after treatment with standard measures of vestibulo-ocular reflex and balance, level of vertigo, gross motor skills, and self-care independence. Subjects in both groups improved significantly on the functional measures, with slightly greater improvements in the occupational therapy group. The results were maintained 3 months after the cessation of intervention. These data suggest that graded purposeful activities are a useful alternative for treating this patient population and that the essential factor in any exercise program is the use of repetitive head movements.

Salt clean-up procedure for the determination of domoic acid by HPLC

Domoic acid (DA) was first reported in mussels from Prince Edward Island, Canada, in 1987. It reappeared in anchovies and pelicans from Monterey Bay, California, in 1991. Later that year, domoic acid was found in razor clams and Dungeness crabs along the Washington and Oregon coasts. Since the initial outbreak, a variety of analytical methods for the detection of this neurotoxin have been developed. Here, we describe a modification to the solid phase extraction (SPE) clean-up step in Quilliam's HPLC-UV method (1991: NRCC No. 33001). The standard 10% acetonitrile (MeCN) wash and 0.5M ammonium citrate buffer (ACB) in 10% MeCN (pH = 4.5) eluting solution have been replaced with a 0.1M sodium chloride (NaCl) in 10% MeCN wash and a 0.5M NaCl in 10% MeCN eluting solution. This modification allows the analysis to work equally well on both clam and crab viscera and meat. Chromatograms of visceral samples no longer contain interfering or late eluting peaks; and all chromatograms are free of the large solvent peak tailing associated with the ACB eluent. The newly modified method allows for an improved and more versatile domoic acid analysis.

Occurrence of domoic acid in Washington state razor clams (Siliqua patula) during 1991-1993

The presence of domoic acid in aquatic species was reported for the first time in the United States in the late summer of 1991 in Monterey Bay, California. By October of 1991, domoic acid was found in razor clams (Siliqua patula) and in the viscera of Dungeness crab (Cancer magister) along the coasts of Washington and Oregon. In response to this outbreak, the National Marine Fisheries Service, in cooperation with the Washington State Department of Fisheries began analysis of Washington State razor clams for the period from November 1991 to June 1993. This survey indicated that domoic acid levels in the edible portion of the razor clams peaked in December of 1991 (average of all Washington state coastal sites: 106 ppm) and followed a slow decline to the present day low levels (< 5 ppm). Sixteen months after the maximum level, domoic acid has not completely disappeared from the razor clams from the Washington State beaches. Unlike mussels (Mytilus edulis), where the toxin is found only in the viscera, domoic acid distributes itself throughout the various body parts of the razor clam. The highest concentration occurs in the foot or "digger" and the lowest in the siphon or "neck." The concentration of domoic acid in the razor clam foot reached a high of 230 ppm.