Effect of lidocaine on the minimum alveolar concentration of sevoflurane in dogs

Objective  To investigate the effects of a low-dose constant rate infusion (LCRI; 50 μg kg⁻¹ minute⁻¹) and high-dose CRI (HCRI; 200 μg kg⁻¹ minute⁻¹) lidocaine on arterial blood pressure and on the minimum alveolar concentration (MAC) of sevoflurane (Sevo), in dogs.
Study design  Prospective, randomized experimental design.
Animals  Eight healthy adult spayed female dogs, weighing 16.0 ± 2.1 kg.
Methods  Each dog was anesthetized with sevoflurane in oxygen and mechanically ventilated, on three separate occasions 7 days apart. Following a 40-minute equilibration period, a 0.1-mL kg⁻¹ saline loading dose or lidocaine (2 mg kg⁻¹ intravenously) was administered over 3 minutes, followed by saline CRI or lidocaine LCRI or HCRI. The sevoflurane MAC was determined using a tail clamp. Heart rate (HR), blood pressure and plasma concentration of lidocaine were measured. All values are expressed as mean ± SD.
Results  The MAC of Sevo was 2.30 ± 0.19%. The LCRI reduced MAC by 15% to 1.95 ± 0.23% and HCRI by 37% to 1.45 ± 0.21%. Diastolic and mean pressure increased with HCRI. Lidocaine plasma concentration was 0.84 ± 0.18 for LCRI and 1.89 ± 0.37 μg mL⁻¹ for HCRI. Seventy-five percent of HCRI dogs vomited during recovery.
Conclusion and clinical relevance  Lidocaine infusions dose dependently decreased the MAC of Sevo, did not induce clinically significant changes in HR or arterial blood pressure, but vomiting was common during recovery in HCRI.     

Twig and stem blight of cotton caused by Botryodiplodia theobromae

A twig and stem blight of cotton ( Gossypium hirsutum ) was observed in Tamil Nadu, India in 1977. The causal organism was isolated in pure culture and identified as Botryodiplodia theobromae , a first record of this species causing twig and stem blight on cotton. Typical fruit rot symptoms were produced on several inoculated fruits but not Citrus sp., Punica granatum or Achras sapota.     

CONTRAST PARANASAL SINUSOGRAPHY FOR EVALUATION OF DISEASE OF THE PARANASAL SINUSES OF FIVE HORSES

Positive-contrast paranasal sinusography was employed to evaluate 5 horses with disease of the paranasal sinuses. Diseases of the paranasal sinuses of these horses were progressive ethmoidal hematoma, bacterial sinusitis secondary to dental disease, and neoplasia. Positive-contrast sinusography allowed more complete evaluation of disease of the paranasal sinus of the horse than did survey radiographs.     

Ventilatory and Metabolic Compensation in Dogs With Acid-Base Disturbances

Ventilatory and metabolic compensation to acid-base disturbances is reviewed. The mechanisms for compensation as well as the values obtained from several studies using normal dogs and dogs with experimentally induced diseases are provided. Compensation is not the same in dogs and human beings. Dogs have a better ability to adapt to most respiratory disorders, and human beings adapt better to metabolic acidosis. In metabolic alkalosis and chronic respiratory acidosis there is no difference in compensation between these species. Ventilatory compensation for metabolic disorders in dogs is the same whether they have metabolic acidosis or metabolic alkalosis, whereas metabolic compensation in respiratory disturbances is less effective in acidosis. Values for the expected changes in PCO₂ in dogs with metabolic acidosis and metabolic alkalosis, and for bicarbonate concentration (HCO₃-) in dogs with acute and chronic respiratory alkalosis and acidosis are presented.     

EQUINE PARANASAL SINUSOGRAPHY

Contrast paranasal sinusography was a simple procedure that enhanced evaluation of the paranasal sinuses in the standing horse. Two techniques of positive-contrast paranasal sinusography were developed using cadavers and sedated horses. For both techniques, 37% organically bound iodine was used. For the first technique, the conchofrontal sinus was injected with 30 ml of contrast medium followed by an additional 100 ml and 70 ml. For the second technique, the rostral maxillary sinus was injected with 20 ml followed by an additional 50 ml. Each technique enhanced visualization of different paranasal sinuses, and each was necessary for complete positive-contrast radiographic evaluation of the paranasal sinuses. The techniques of positive-contrast radiographic evaluation of the paranasal sinuses are described.