Case Summary A six year old mixed breed neutered female dog (bodyweight 23kg) presented to the emergency service of Vets-Now Referrals with severe generalised tremors. The patient was conscious but laterally recumbent, hyperthermic (rectal temperature 39.5⁰C) and had vomited a quantity of mouldy material.
Baseline haematological, electrolyte and vital parameters were unremarkable.
Tremors were refractory to intravenous diazepam, and a constant rate infusion (CRI) of propofol and intermittent intravenous medetomidine and butorphanol provided partial and temporary relief only.
Due to unrelenting clinical signs of approximately thirteen hours duration, and after obtaining informed consent from the patients’ owner, intravenous lipid rescue therapy (ILR) was administered via a cephalic venous catheter (1.5ml/kg bolus followed by a constant rate infusion of 15ml/kg/hr for sixty minutes; Intralipid 10%, Fresenius Kabi). During this time, the propofol CRI was continued.
Severity of tremors was quantified using Overall Dynamic Body Acceleration (ODBA) [1] utilising the tri-axial accelerometer contained within a smartphone (Motorola Defy; Motorola, U.S.A). Briefly, the smartphone was secured to the dorsal thorax of the patient using a modified Velcro harness. A widely available smartphone application was used to record acceleration in the x, y and z axis’ [2], and the data was exported to a spread sheet for analysis (Excel; Microsoft, U.S.A.). ODBA was calculated by measuring the area under the curve created by the summation of the tri-axial acceleration over a ten second period.
Measurements were obtained before, during and after ILR therapy. In comparison, ODBA was also measured in a population of normal dogs.
Following the initial ILR infusion, subjective assessment suggested a reduction in severity of clinical signs. This was confirmed by the post-hoc analysis of ODBA, which had reduced by approximately one third. However, tremors persisted and ODBA did not approach that of the population of normal dogs.
An additional infusion of ILR was administered (1.5ml/kg bolus followed by a constant rate infusion of 15ml/kg/hr for thirty minutes) but no further improvement was identified either by subjective assessment or ODBA.
The propofol CRI was subsequently stopped, with no immediate detectable worsening of signs. Nevertheless, additional therapeutic interventions were required to completely abolish the tremors (intermittent medetomidine and butorphanol iv administered as required). The patient steadily improved and was discharged three days later.
Vomitus was submitted for toxicological analysis by High Performance Liquid Chromatography (Idexx Laboratories, U.K.), whereupon Roquefortine was identified (octanol-water partition coefficient (logP) 5.085 [3]).
Clinical relevance This is the first report of intravenous lipid rescue therapy for tremorgenic mycotoxicosis caused by Roquefortine. Although clinical signs improved following treatment, this was insufficient to withdraw additional anticonvulsant therapies, and the possibility of spontaneous improvement cannot be discounted.
Nevertheless, measurement of ODBA using a smartphone application represents a simple, novel and objective technique to assess the impact of ILR on drug induced tremors, and may have applications in the study of ILR for other intoxictaions such as feline permethrin intoxications.
References [1] Shephard, E.L.C. et al (2008) Derivation of body motion via appropriate smoothing of acceleration data. Aquat Bio. 4 235-241 [2] https://play.google.com/store/apps/details?id=com.lul.accelerometer&hl=en (Accessed 12th November 2013) [3] www.chemspider.com (Accessed 12th November 2013)
AUTHORS Parratt, C.A. 1,2
AFFILIATION 1CrumPets Veterinary Services Ltd, Glasgow, Scotland. 2 Vets-Now Referrals, Glasgow, Scotland
Case Summary
A six year old mixed breed neutered female dog (bodyweight 23kg) presented to the emergency service of Vets-Now Referrals with severe generalised tremors. The patient was conscious but laterally recumbent, hyperthermic (rectal temperature 39.5⁰C) and had vomited a quantity of mouldy material.
Baseline haematological, electrolyte and vital parameters were unremarkable.
Tremors were refractory to intravenous diazepam, and a constant rate infusion (CRI) of propofol and intermittent intravenous medetomidine and butorphanol provided partial and temporary relief only.
Due to unrelenting clinical signs of approximately thirteen hours duration, and after obtaining informed consent from the patients’ owner, intravenous lipid rescue therapy (ILR) was administered via a cephalic venous catheter (1.5ml/kg bolus followed by a constant rate infusion of 15ml/kg/hr for sixty minutes; Intralipid 10%, Fresenius Kabi). During this time, the propofol CRI was continued.
Severity of tremors was quantified using Overall Dynamic Body Acceleration (ODBA) [1] utilising the tri-axial accelerometer contained within a smartphone (Motorola Defy; Motorola, U.S.A). Briefly, the smartphone was secured to the dorsal thorax of the patient using a modified Velcro harness. A widely available smartphone application was used to record acceleration in the x, y and z axis’ [2], and the data was exported to a spread sheet for analysis (Excel; Microsoft, U.S.A.). ODBA was calculated by measuring the area under the curve created by the summation of the tri-axial acceleration over a ten second period.
Measurements were obtained before, during and after ILR therapy. In comparison, ODBA was also measured in a population of normal dogs.
Following the initial ILR infusion, subjective assessment suggested a reduction in severity of clinical signs. This was confirmed by the post-hoc analysis of ODBA, which had reduced by approximately one third. However, tremors persisted and ODBA did not approach that of the population of normal dogs.
An additional infusion of ILR was administered (1.5ml/kg bolus followed by a constant rate infusion of 15ml/kg/hr for thirty minutes) but no further improvement was identified either by subjective assessment or ODBA.
The propofol CRI was subsequently stopped, with no immediate detectable worsening of signs. Nevertheless, additional therapeutic interventions were required to completely abolish the tremors (intermittent medetomidine and butorphanol iv administered as required). The patient steadily improved and was discharged three days later.
Vomitus was submitted for toxicological analysis by High Performance Liquid Chromatography (Idexx Laboratories, U.K.), whereupon Roquefortine was identified (octanol-water partition coefficient (logP) 5.085 [3]).
Clinical relevance
This is the first report of intravenous lipid rescue therapy for tremorgenic mycotoxicosis caused by Roquefortine. Although clinical signs improved following treatment, this was insufficient to withdraw additional anticonvulsant therapies, and the possibility of spontaneous improvement cannot be discounted.
Nevertheless, measurement of ODBA using a smartphone application represents a simple, novel and objective technique to assess the impact of ILR on drug induced tremors, and may have applications in the study of ILR for other intoxictaions such as feline permethrin intoxications.
References
[1] Shephard, E.L.C. et al (2008) Derivation of body motion via appropriate smoothing of acceleration data. Aquat Bio. 4 235-241
[2] https://play.google.com/store/apps/details?id=com.lul.accelerometer&hl=en (Accessed 12th November 2013)
[3] www.chemspider.com (Accessed 12th November 2013)