Anaesthesia Flashcards
The effects of flumazenil on ventilatory and recovery characteristics in horses following midazolam-ketamine induction and isoflurane anaesthesia
Flumazenil given during anaesthesia hastened recovery without lower score and imrpoved minute volume. No difference in oxygenation but all healthy horses in lateral recumbency (well oxygenated)
Preoperative and intraoperative risk factors for post-anaesthetic pulmonary oedema in horses
RE: gastric reflux and FFP.
Associated: Ascarid impation- pneumonitis
Cardiopulmonary function and intestinal blood flow in anaesthetised, experimentally endotoxaemic horses given a constant rate infusion of dexmedetomidine
DexMDT reduces acidaemia (HCO3, BE and pH) and hypercreatinaemia in endotoxic horses without sustained adverse CV effects
Risk factors associated with hypoxaemia in horses undergoing general anaesthesia: A retrospective study
> 550kg, PIP>30cmH2O, STS (do recumbency), ex lap increases likelihood of hypoxaemia.
Hypoxic event reduces likelihood of survival to discharge by 60%
Comparison of Thoracic Ultrasonography Findings in Healthy Horses Before and After General Anesthesia for Elective Magnetic Resonance Imaging (GA does not induce ultrasonographic changes in the pleura of healthy adult horses anaesthetised for elective MRI)
No difference in US 3 hours after elective MRI under GA
Recovery of horses from general anaesthesia: A systematic review 2000-2020
- provision of adequate analgesia for painful procedures is crucial
- the use of certain agents as part of a PIVA protocol and cessation of intravenous lidocaine 30 minutes before the end of anaesthesia may benefit recovery.
Alpha2s help, but no consensus on type or timing.
Low-moderate certaintly in conclusions
Recovery of horses from general anaesthesia: A systematic review (2000-2020) of risk factors and influence of interventions during the recovery period
alpha2s help but no consensus on which, assistance during recovery unclear
ASA grade (OR 1.5-2.1), Fx repair/ex lap/ocular Sx, age (negative), body mass, (?temprement), OOH anaesthesia (OR 1.6), MAP <70mmHg, PaO2 <60mmHg, duration of anaesthesia
Limitations: no consensus on grading system, studies generally underpowered.
The effect of xylazine on ICP in anaesthetised and standing horses
CBP= CPP/CVR. CPP= MAP-ICP
- Average ICP in anesthetized horses: 24.5 ± 3 mm Hg.
- Average ICP in conscious horses: 2.6 ± 3.65 mm Hg.
Xylazine can decrease ICP and increase CPP in anesthetized horses. No effect shown in standing horses (1mg/kg)
Caudal epidural co-administration of methadone and morphine in horses: An evaluation of analgesic properties and effects on locomotor function, mentation and physical examination parameters
- methadone= lipophilic= quick onset, short duration
-morphine= hydrophilic= slow onset, long duration - combination (0.1mg/kg of each)- analgesia detectable from 4.4-9.4 hours- similar to morphine alone BUT testing methods insensitive so may miss effects of methadone.
- no effect on mentation/ locomotion/ PE.
Increased body condition score has a detrimental effect on arterial oxygen tension and increases the risk of hypoxaemia in anaesthetised horses
- Obese horses: lower PaO2, increased alveolar dead space and 34x more likely to be hypoxaemic.
- have increased PIP and dobutamine requirements
Recovery quality following a single post-anaesthetic dose of dexmedetomidine or romifidine in sevoflurane anaesthetised horses
- DexMDT and romifine equivalent in recovery quality, but DexMDT may result in less ataxia once up
- associated with recovery quality: age, nerve block (Y.N), hypotension duration and nervousness
Retrobulbar lidocaine injection via the supraorbital fossa is safe in adult horses but produces regionally variable periocular anaesthesia
- corneal anaethesia 6 hours
- dorsal and medial periocular- 2 hours. Combine with zygomatic and lacrimal blocks
- increase in pupil size within 5 mins indicates anaesthesia
Effects of pulsed inhaled nitric oxide on arterial oxygenation during mechanical ventilation in anaesthetised horses undergoing elective arthroscopy or emergency colic surgery
PiNO and mechanical ventilation significantly improves oxygenation in anaesthetised horses, reducing F-shunt; effects were present even in colics
Comparison of xylazine and detomidine with midazolam/ketamine for field castration in Quarter Horses
Can use detomidine instead of xylazione in field anaesthesia- better anaesthesia, longer (but good) recovery times
Rethinking equine anaesthetic risk: Development of a novel Combined Horse Anaesthetic Risk Identification and Optimisation Tool (CHARIOT)
Factors involved in CHARIOT tool: : age, weight, tractability, mobility, pain level, procedure performed, recovery assistance available, anticipated duration of anaesthesia, position during recumbency and abdominal profile.
Propsed as an alternative to current Anaesthesiologists Physical Status Classification System (ASA-PS)
