Chapter 20 - Anesthesia and Analgesia for foals Flashcards
What is considered neonate?
0-1 month
What is considered pediatric?
1-3 months
What is considered juvenile
3 - 4 months
Patients under 1 year old the perioperative moratlity rate is ___%
Older than 1 year old?
1.9% - baby
1% adult
What is the definition of cardiac output?
Amount of blood ejected by heart per minute and is calculated as product of HR (min) and stroke volume (mL)
Cariovascular: When they are neonate (<1month) they are dependent on HR or Stroke volume for cardiac output?
HR
Cardiovascular pediatric (1-4mo) it is more HR or Stroke Volume?
Increased or decreased systemic vascular resistance?
More SV less HR dependent cardiac output
Increasing systemic vascular resistance
In Neonate (<1mo) is this TRUE or FALSE?
High Respiratory Rate-dependent Volume per minute and low min, low VT (tidal volume)
True
Neonates have higher or lower BBB permeability?
Higher
In Pediatric juvenile (1-4mo) the Vmin and RR are higher or lower?
VT is is low, high or normal?
Higher minute ventilation volume (Vmin) and RR
Normal Volume Tidal
Neonates have higher ECG (extracellular fluid volume) or lower?
Higher compartment circulating blood volume (CBV) and circulating plasma volume (CPV)
neonates have high or low glycogen reserves?
Low glycogen reserves
When does the liver starts to mature?
3-4 weeks
The PCV in neonates if decreased is often due to what?
isoerythrolysis
When does the PCV normalize, the WBC is the normal of adult and elevated serum enzyme activities are present?
Pediatric/juvenile foal of 1-4 months
series of extracardiac shunts (ductus venosus, patent ductus arteriosus) and intracardiac communication (foramen ovale) are necessary for what in fetal stage?
To suply deoxygenated blood to the placenta and return oxygenated blood to systemic organs
Oxygenated blood arriving in the fetus via the umbilical vein flows through the _________________________ (2 words) and _____________ (2 words) towards the ____________ side of the heart
ductus venosus and the caudal vena cava towards the right side of the heart
Having entered the right atrium, most blood is diverted away from the noninflated lung to the _______ atrium via the _____________________ (2 words)
left atrium via the foramen ovale an opening in the atrial septum that connects both atria
Only a small portion of the blood that entered the _____ atrium continues its path through the _______ ventricle into pulmonary artery
right atrium right ventricle
from the pulmonary artery, it bypasses the lung by flowing through the patent ductus arteriosus into the __________
into the aorta a process that depends on the high pulmonary arterial resistance prevailing within the fetus’s not yet aerated lung
At birth, the function of gas exchange is abruptly transferred from the placenta to the lungs by activation from systemic to _____________ circulation
pulmonary
Due to aeration of the lungs a dramatic _______________ increase/decrease in pulmonary arterial resistance, thereby promoting blood flow through the pulmonary vasculature
decrease in pulmonary arterial resistance - As a result, the blood pressure in the left atrium increases relative to the pressure in the right atrium, pushing a valve that lies over the foramen ovale on the left side of the atrial septum against it and thus largely preventing any further right-to-left blood flow through the foramen ovale
decrease in circulating __________________ that accompanies perinatal adaptation also promotes the closure of the ductus arteriosus over time.
prostaglandins
Fulfilling the needs of metabolically highly active organs and tissues during early postnatal life, the CI in resting foals up to 2 to 3 months of age is markedly ___________ when compared to adults
Higher
Are heart murmurs normal in the first 3 to 5 days of life?
yes, closing of the ductus arteriosus does not occur immediately at birth and therefore right-to-left shunting may continue; murmurs consistent with a patent ductus arteriosus may be auscultated and blood flow within the ductus arteriosus
Define cardiac index (CI)
Cardiac output is the amount of blood ejected by heart per minute (min) and is calculates as the product of heart rate (min) and stroke volume (mL) and when normalized to body weight is reffered to as the cardiac index (CI) (mL/min/kg).
CI is higher or lower in foals up to 2 to 3 monthscompared to adults
higher, average CI in foals is approximately twice that of adults, but the average stroke volume index 30% less –> that is why HR is high to maintain CO
What is the incovenient ot give α2-adrenoceptor agonists in foals?
may compromise hemodynamic function to an extent that the neonate cannot tolerate. From 4 months of age onward, heart rates reach close to adult values and remain relatively stable throughout the remainder of the first yea
Systemic arterial blood pressure is higher or lower in early days of life?
Lower, but pulse pressure amplitude is higher in the neonate compared to the adult owing to a lower vasomotor tone and hence systemic vascular resistance
By 1 month of age foals tend to have a _________ CI and HR but a ______ SV and their mean arterial pressure increases during this period because of a marked__________in vascular resistance indicative of the maturing sympathetic branch of the autonomic nervous system.
By 1 month of age foals tend to have a lower CI and heart rate but a larger stroke volume, and their mean arterial pressure increases during this period because of a marked increase in vascular resistance indicative of the maturing sympathetic branch of the autonomic nervous system.
Poney lung are more mature or less mature than horse lungs?
Poney lung are more mature
In foals functional residual capacity (FRC; i.e., the gas volume left in the lung after a normal expiration) and tidal volumes are markedly _________than in the adult
smaller
first week postpartum, O2 consumption how many mL/kg/min
6-8 mL/kg/min exceeds that of the adult horse by two- to threefold, requiring increased respiratory minute ventilation
FRC and tidal volume, newborn foals typically breath up to ____ to ____ times per minute,
60-80 times per minute, which in the 4th to 6th week declines to 30 to 40 breaths per minute for the remainder of the first 3 months of life before gradually approaching adult values
newborn foal the total body water content in %
72 to 74% of total body mass and does not change over first 5 months of life
The extracellular fluid (ECF) compartment is about ______third larger in foals on a per kilogram body weight basis than in adults
The extracellular fluid (ECF) compartment is about one third larger in foals on a per kilogram body weight basis than in adults
because of the higher capillary permeability in the neonate yet greater systemic arterial blood pressures postpartum, intravascular water rapidly redistributes into the ______________________ (2 words)
because of the higher capillary permeability in the neonate yet greater systemic arterial blood pressures postpartum, intravascular water rapidly redistributes into the interstitial space where it accumulates
Maintenance fluid rates in neonatal foals
80 to 120 mL/kg/day (3.5–5.0 mL/kg/h) is required in foals up to 1 month of age
Based on the Holliday-Segar formula, the daily fluid requirements can be calculated for each individual foal as:
100 mL/kg/day for the first 10 kg of body weight (BW) + 50 mL/kg/day for the second
10 kg of BW + 20 to 25 mL/kg/day for the remaining BW
Why is teh foal more susceptible to hypoglycemia?
Glycogen reserves in liver and muscle are smaller in the newborn foal than in neonates of other species and last only for a few hours
What is the value of hypoglicemia in foals poorer survival to hospital discharge and was commonly associated with sepsis, systemic inflammatory response syndrome (SIRS), and bacteremia?
glucose<75mg/dL
What is the rectal temperature of foals
rectal temperature of foals ranges from 37.2°C to 38.6°C
equine neonates have the ability to generate heat through _______
shivering
Where is the principal site of drug metabolism?
Liver
At what time most of hepatic metabolic pathways are completely functioning?
6-12 weeks postpartum
Normal urine output in neonatal foals is reported to be
6 mL/kg/h but then decreases gradually over the subsequent 12 weeks of life
normal urine specific gravity in newborn foals, after the first 24 hours postpartum, is usually ______________ (hypo/iso/hypersthenuric) and is reported to range from 1.001 to 1.027
normal urine specific gravity in newborn foals, after the first 24 hours postpartum, is usually hyposthenuric (<1.008) and is reported to range from 1.001 to 1.027
Blood volume in neonates is _____________higher/lower than in adults
Blood volume in neonates is higher than in adults (approximately 13%–15% of total body weight),
Marked hyperbilirubinemia in the first week of life is a common finding and can be attributed to ……
to an accelerated breakdown of neonatal erythrocytes and immature hepatic function
Serum enzyme activities (including creatinine kinase, sorbitol dehydrogenase, γ-glutamyl transferase, lactate dehydrogenase, and aspartate aminotransferase) have been reported to be transiently elevated in the first few weeks after birth. Why?
as a result of hepatocellular maturation
Serum lactate concentrations are high immediately after birth. What value?
Serum lactate concentrations are high immediately after birth (3–5 mmol/L), likely because of temporary tissue hypoperfusion and hypoxia, but then soon decrease to normal values (<2 mmol/L).
Dosage midazolam (benzodiazepine) for sedation of neonate
0.05–0.1 mg/kg
If, however, sedation is required or the animal is older than 2 to 3 weeks, a benzodiazepine derivative is the preferred choice for lack of serious adverse cardiopulmonary effects.
Dosage diazepam (benzodiazepine) for sedation of neonate
0.1–0.25 mg/kg
If, however, sedation is required or the animal is older than 2 to 3 weeks, a benzodiazepine derivative is the preferred choice for lack of serious adverse cardiopulmonary effects.
Dosage lorazepam (benzodiazepine) for sedation of neonate
0.02–0.05 mg/kg If, however, sedation is required or the animal is older than 2 to 3 weeks, a benzodiazepine derivative is the preferred choice for lack of serious adverse cardiopulmonary effects.
Dosage climazolam (benzodiazepine) for sedation of neonate
0.1–0.2 mg/kg
If, however, sedation is required or the animal is older than 2 to 3 weeks, a benzodiazepine derivative is the preferred choice for lack of serious adverse cardiopulmonary effects.
α2-Agonists (not preferred in neonates only >8w)
* Xylazine in neonates
Xylazine 0.2–0.5 mg/kg
Supplementation of α2-Agonists with morphine say dosage in neonates
morphine 0.03-0.06 mg/kg
Supplementation of α2-Agonists with L-methadone say dosage in neonates
L-methadone 0.05 mg/kg
Supplementation of α2-Agonists with burtphanol say dosage neonates
Butorphanol 0.05–0.1 mg/kg and in juvenile is 0.02-0.1 mg/kg
For induction you can use Injectable anesthetics (after sedation)
* Alfaxalone
* Ketamine
* Propofol say dosage of each
Alfaxalone 1.0–3.0 mg/kg
* Ketamine 2.0–2.5 mg/kg
* Propofol 2.0–2.5 mg/kg
TIVA in neonates is with propofol and in juvenile? say dosage
Propofol 0.2–0.4 mg/kg/min
Juvenile: TIVAa
* Triple-drip CRI
* Alfaxalone 0.03 mg/kg/min−1
* Propofol 0.1–0.3 mg kg/min−
Dosage of acepromazine alone for the mare
0.02-0.05 mg/kg IV/IM
Wha are the consequences of propylene glycol veichule in certai benzodiazepine such as diazepam lorazepam and climazolam?
can cause metabolic acidosis, nephrotoxicity, hyperosmolarity, and subsequent tissue irritation and hemolysis
benzodiazepine’s effects can be reversed at the end of the procedure using what?
Flumazenil 0.025-0.1 mg/kg IV
opiods’s effects can be reversed at the end of the procedure using
Naloxone (10-15 μg/kg IV), or levallorphan (Lorfan; 22 μg/kg IV),
xylazine effects can be reversed at the end of the procedure using
yohimbine or atipamezole
(Yocon; 0.1–0.2 mg/kg IM) or atipamezole (Antisedan; 0.05–
0.2 mg/kg IV/IM)
Advantage of using volatile anestehtic alone in neonates (1) both rapid uptake and elimination of the anesthetic via the lungs why?
(1) both rapid uptake and elimination of the anesthetic via the lungs because of high minute ventilation and CO;
volatile anesthetics have greater potency in early life?
yes isoflurane minimal alveolar concentration [MAC] of 0.84% in the equine neonate versus 1.3%–1.6% in adult horses)
Depending on the age and hence size of the animal,how many L rebreathing bags or bellows are sufficient?
3- to 5-L rebreathing bags or bellows are sufficient
Sevoflurane and desflurane are characterized by a _% and __% lower blood solubility than isoflurane,
Sevoflurane and desflurane are characterized by a 50% and 64% lower blood solubility than isoflurane,
ketamine lasts how much time
10 to 20 minutes
Thiopental in conjunctionwith benzodiazepine or guaifenesin is suitable for induction in foals with which type of conditions?
Seizures and brain trauma
Neonates and juveinle foals general anesthesia s maintained with isoflurane - wich MAC?
1.3-1.6% Iso or 2.3-2.8% Sevoflurane
What size is the nasotracheal tube in foals?
6-9mm ID
What size is the endotracheal tube?
8-14 mm ID
Bolus and infusion dosage of lidocaine
50 μg/kg/min after an IV bolus of 1.2–1.5 mg/kg
Triple drip refers to a combination of which drugs and what dosage?
Ketamine 1g/L
Xilazine 250 mg/L
Guaifenesin solution
Drip maintenace is 2 to 3 mL/kg/h
What are the parameters for monitoring anesthesia depth?
Physical signs such as
1 - position of the eye globe, 2 - nystagmus,
3 - degree of depression of protective eye reflexes (palpebral and corneal), 4 - presence or loss of swallowing reflex,
5 - rate and depth of breathing, lacrimation,
6 - skeletal muscle shivering/trembling or tightening,
7- anal sphincter reflex, as well as hemodynamic responses to noxious stimulation are commonly evaluated
Mention the 4 peripheral arteries used for invasive method by catheterization
1 - facial
2 - transverse facial
3- auricular
4 - metatarsal artery
In critical ill foal what are the additional hemodynamic monitoring?
central venous pressure
urine output
cardiac output
What are the minimal invasive tx that have been developed to assess cardiac output?
Lithium dilution (LidCO) tx
Non invasive cardiac output tx NICO based on the FIck principle and partial rebreathing of Co2 and US velocity dilution tx (UCDO)
Where can you place the continuous monitoring of arterial hemoglobin oxygen saturation by pulse oximetry=
By nninvasive tx of clipe-type probe on the:
ear
tongue
nonpigmented skin
nonpigmented mucosa
The PaCo2 changes proportionately with metabolic activity and inversely with its _____________ (1word)
elimination (i.e., alveolar ventilation).
value in excess of 45 mm Hg (hypercapnia) indicates
hypoventilation,
alue below 35 mm Hg (hypocapnia) indicates
hyperventilation
limited glycogen reserves in the neonate make it susceptible to the development of hypoglycemia during prolonged anesthesia. When do we consider long?
> 1–1.5 h
glucose levels below _____mg/dL may produce deleterious central nervous effects such as seizure activity, cerebral depression, and even permanent neuronal damage
40 mg/dL
blood glucose concentration has been identified as a prognostic indicator in critically ill neonatal foals - TRUE or FALSE
TRUE
temperature should be continuously monitored in 3 places name them
pharyngeal
esophageal
rectal
Systemically healthy normovolemic foal under GA the infusion rate taht has been reported as adequate to maintain an appropriate circulatory volume?
the maintenance rate of 3 to 5 mL/kg/h reported for foals.
In adults, 20% to 50% (dependent, in part, on the state of hypovolemia and dehydration) of an isotonic fluid load is retained in the intravascular space ___ to ____ minutes after infusion
30 to 60 minutes after infusion
Dehydration and absolute hypovolemia as a result of persistent diarrhea, sepsis, septic shock, heat shock, or acute hemorrhage require immediate intravenous fluid substitution dosage mL/kg
50 to 80 mL/kg, typically given one third at a time followed by reassessment of the foal’s volume status
Colloids, including synthetic solutions (e.g., dextrans, hetastarch, pentastarch), and plasma may be required if the TPP or albumin concentrations are ______and are used to supplement __________fluid therapy.
Colloids, including synthetic solutions (e.g., dextrans, hetastarch, pentastarch), and plasma may be required if the TPP or albumin concentrations are low crystalloid and are used to supplement crystalloid fluid therapy
hetastarch may be administered slowly (0.5–1.0 mL/kg/h) up to a dose of ____mL/kg/day for treatment in hypooncotic animals
hetastarch may be administered slowly (0.5–1.0 mL/kg/h) up to a dose of 10 mL/kg/day for treatment in hypooncotic animals
Oxygen may be delivered via face mask, nasal cannulae, or a nasotracheal tube and at a rate of___ to ____ L/min.
Oxygen may be delivered via face mask, nasal cannulae, or a nasotracheal tube and at a rate of 5 to 10 L/min.
Why should oxygen be humidified?
O2 should be humidified by means of a bubble humidifier to minimize nasal and tracheal mucosal irritation and avoidable water losses in the foal, if applied over several hours.
What are the multiple factors may contribute to severe respiratory depression and impairment of pulmonary gas exchange leading to poor arterial oxygenation and CO2 retention
persistent pulmonary hypertension,
drug-induced central respiratory center depression,
reduced FRC, exhaustion of respiratory muscles from increased work of breathing,
immature lung, lung disease,
and airway obstruction
Among all different modes of mechanical (i.e., positive pressure) ventilation, controlled ____________________(2w) is the mode most commonly used during equine anesthesia in foals.
Among all different modes of mechanical (i.e., positive pressure) ventilation, controlled mandatory ventilation (CMV) is the mode most commonly used during equine anesthesia in foals.
Mechanical ventilation may be employed in two different modalities:
pressure-limited (targeted) or volume-limited (targeted) ventilation
Mechanical ventilation in the neonatal foal are a tidal volume of __ to __ mL/kg, a rate of __ to ___ min(−1), a peak flow of ___ to ___ mL/min, I:E ratio of 1 : 2, and a peak inspiratory pressure of ___ to ___ cm H2O
Typical settings to begin mechanical ventilation in the neonatal foal are a tidal volume of 6 to 8 mL/kg, a rate of 20 to 30 min−1, a peak flow of 60 to 90 mL/min, I:E ratio of 1 : 2, and a peak inspiratory pressure of 8 to 12 cm H2O.47
It is not necessary to ventilate foals with 100% O2 - TRUE or FALSE
True
opioid agonist-antagonist butorphanol (0.05 mg/kg IV/IM) has been tested in newborn. The elimination half-life was__________ hours
the elimination half-life was 2.1 hours after IV injection
butorphanol exhibits antinociceptive properties only after doses of _____ mg/kg and if plasma concentrations of the drug reach or exceed a threshold of ___ ng/mL
butorphanol exhibits antinociceptive properties only after doses of 0.1 mg/kg and if plasma concentrations of the drug reach or exceed a threshold of 10 ng/mL
Name the dosages:
Flunixin meglumine IV/IM q 24–36 h
* ____mg/kg (foal <24 h)
* _____ mg/kg (foal 1–4 wks)
Phenylbutazone____mg/kg IV/PO q 12–24 h
Meloxicam ______ mg/kg IV q 8–12 h
Ketoprofen ____ mg/kg IV q 24 h
Ibuprofen ______ mg/kg IV/PO q 8 h
Flunixin meglumine IV/IM q 24–36 h
* 1.4 mg/kg (foal <24 h)
* 0.5–1.0 mg/kg (foal 1–4 wks)
Phenylbutazone 2.2 mg/kg IV/PO q 12–24 h
Meloxicam 0.5–0.6 mg/kg IV q 8–12 h
Ketoprofen 1–2 mg/kg IV q 24 h
Ibuprofen 10–20 mg/kg IV/PO q 8 h
Name the dosages: Butorphanol ____-____ mg/kg IV
Butorphanol ___–___ mg/kg IM
Buprenorphine ____ mg/kg IM
Morphine __–___ mg/kg IV, IM
L-Methadone ____–___ mg/kg IV, IM
Transdermal fentanyl (____-μg/h patch)
Butorphanol 0.01–0.04 mg/kg IV
Butorphanol 0.02–0.08 mg/kg IM
Buprenorphine 0.01 mg/kg IM
Morphine 0.1–0.2 mg/kg IV, IM
L-Methadone 0.05–0.1 mg/kg IV, IM
Transdermal fentanyl (100-μg/h patch)
Xylazine ___–___ mg/kg IV (use sparingly in foal colic because of adverse effects on cardiovascular and respiratory systems and GI motility)
Medetomidine ___–___μg/kg SQ
Dexmedetomidine ___–____ μg/kg SQ
Xylazine 0.1–0.5 mg/kg IV (use sparingly in foal colic because of adverse effects on cardiovascular and respiratory systems and GI motility)
Medetomidine 1–2 μg/kg SQ
Dexmedetomidine 0.5–1.0 μg/kg SQ
Lidocaine 30–___ μg/kg/min following 1.3–1.5 mg/kg IV loading dose
Lidocaine 30–50 μg/kg/min following 1.3–1.5 mg/kg IV loading dose
aDetomidine doses of 10–20 μg/kg have frequently been associated with significant
(brady-)arrhythmias
Intra-articular preservative-free morphine dosage to provide analgesia in foals affected by septic arthritis/synovitis
0.05 mg/Kg
Fentanyl patches have been tested and after patch placement and plasma concentrations peaked after ____±8 hours and returned to baseline concentrations ____ hours after patch removal
after patch placement and plasma concentrations peaked after 14±8 hours and returned to baseline concentrations 12 hours after patch removal
atrioventricular conduction in bradyarrhythmias should be restored with waht?
Atropine 5–20 μg/kg IV and if doesn’t work
indirect sympathomimetic drug ephedrine 25–50 μg/kg IV
or epinephrine 5–10 μg/kg
Ventricular tachyarrhythmias are treated with
lidocaine as an initial bolus of 1 mg/kg IV followed by subsequent IV doses of 0.5 to 0.75 mg/kg as required or by CRI (20–50 μg/kg/min)
If the lidocaine is unsucessful what should you use?
quinidine gluconate (Quinidine Gluconate Injection, USP; 0.5–2.2 mg/kg IV every 10 min) or propranolol 0.03–0.1 mg/kg IV may be administered to control the dysrhythmia.
In case of systemic arterial hypotension you should treat with
Volume-replacement therapy
In case of hypotension if Volume-replacement therapy fails what should you give?
infusion of dobutamine 1arily used as a positive chronotropic agent in the neonate;
1–5 μg/kg/min
phenylephrine (0.1–3.0 μg/kg/min),
norepinephrine (0.05–1.5 μg/kg/min) titrated to effect or IV ephedrine injections at increments of 0.05–0.1 mg/kg are used to increase and maintain mean arterial blood pressures above 60 to 70 mm Hg.
critically ill foals with severe gastrointestinal disease, blood vessels may become unresponsive to
catecholamines (dobutamine)
In case of non response to dobutamine what can you give?
vasopressin 0.0005–0.001 IU/kg/min)
dobutamine is a catecholamine with wich type of receptorS?
direct-acting inotropic agent and an adrenergic agonist that stimulates primarily the beta-1 adrenoceptor,
how does teh vasopressin work?
acting through V1 receptors on vascular smooth muscle, is required to adequately increase vasomotor tone and thereby diastolic arterial pressure
dobutamine is symphaticomimetic or parasymphaticomimetic
symphaticomimetic
Complete the sentence: hypoventilation is frequent, with _____% of the foals developing marked arterial hypercarbia (PaCO2 >65 mm Hg);
hypoventilation is frequent, with 20% of the foals developing marked arterial hypercarbia (PaCO2 >65 mm Hg);
What should you suspect in a foal that desaturate severly during anesthesia (SaO2 <80%) with PaO2 values decreasing 20 to 40 mm Hg despite being mechanically ventilated and inhaling 100% O2?
return to fetal circulation with persistent pulmonary arterial hypertension and massive right-to-left shunting of blood flow through the foramen ovale or ductus arteriosus
How to reverse this life-threatening situation of sudden desaturate without cyanosis?
Increasing the anesthetic depth in an attempt to reduce pulmonary vascular resistance
What drug can produce selective pulmonary arterial vasodilatation in foals with pulmonary arterial hypertension?
sildenafil (Sildenafil Injection, USP; slowly 0.5–
2.5 mg/kg IV), a type 5 phosphodiesterase inhibitor that produces selective pulmonary arterial vasodilatation and thus ameliorates clinical signs of pulmonary hypertension
What are the arrhythmias most commonly associated with cardiac arrest in foals?
Pulseless electrical activity (PEA)
Asystole
PEA is also known as
flat lining that leads to cardiac arrest
Cardiopulmonary failure in foals has usually 2ary cause to 2 things, name them
systemic disease
anesthetic overdose
Causes of secondary cardiopulmonary arrest encountered in foals include 9 name them
severe hypovolemia,
low cardiac output,
severe metabolic acidosis,
hyperkalemia (e.g., ruptured bladder),
vasovagal reflex,
severe hypoglycemia,
severe hypothermia,
septic shock/endotoxemia, and finally,
pulmonary arterial hypertension with return to fetal circulation and right-to-left shunting of blood, causing systemic tissue hypoxia.
Name the CPR actions of 1 to 5 approach
(1) administration of chest compressions; (2) ventilation support; (3) initiation of ECG and ETCO2 monitoring; (4) obtaining vascular access for drug administration; and (5) administration of reversal agents if any anesthetic/sedative agents have been administered.
what is teh rate of chest compressions? what position should be the foal?
100/min
RLRecumbency on firm surface
What is the rate of breaths in CPR?
A rate of 6 to 10 breaths per minute is sufficient.
Among all drugs tested in CPR, only two exhibit significant efficacy in all cardiac arrest situations: which ones?
Epinephrine0.01 to 0.02 mg/kg Ive every 2 - 3min and vasopressin 0.06 to 0.8 IU/kg given single dose
Epinephrine posses strong __________(1w) properties has been shown to improve coronary perfusion pressure during cardiac arrest
vasoconstrictive (via activation of α-adrenoceptors)
What are teh complications of epinephrine?
Complications of epinephrine administration include ventricular fibrillation (V-fib), pulseless ventricular tachycardia (V-Tach), and an increase in systemic vascular resistance, all increasing myocardial O2 demand and cardiac workload
Electrical defibrillation is indicated at initial charge of _____J/Kg with subsequent defibrillations using a charge of 4 J/kg, delivered 30 to 60 seconds after each epinephrine administration until conversion to normal rhythm occurs
2 J/kg
During the period of cardiac arrest per se, large-volume fluid administration is contraindicated or indicated?
contraindicated
characteristic electrolyte abnormalities of foal with Uroperitoneum
hyponatremia, hyperkalemia, and hypochloremia—was thought to occur in conjunction with azotemia and metabolic acidosis, serum creatinine concentrations were always greatly elevated
In Uroperitoneum most foals develop respiratory distress with increased respiratory rate and respiratory effort as a result of significant a
abdominal distension
How do you stabilize the patient with uroperitoneum?
O2 supplementation via nasal insufflation or mask delivery, restoration of circulating blood volume, correction of electrolyte and acid-base abnormalities, and slow drainage of the peritoneal fluid by abdominocentesis
Once plasma K+ concentrations reach values in excess of 5.5 mEq/L, progressive changes in the ECG such as
Once plasma K+ concentrations reach values in excess of 5.5 mEq/L, progressive changes in the ECG such as
Serum K+ can be effectively decreased to clinically acceptable levels by administering regular ______
insulin at a dose of 0.1 to 0.3 IU/kg slowly IV in 2.5% to 5.0% dextrose over 30 to 45 minutes prior to induction of anesthesia
after initial blood volume restoraiton with physiologic saline or ______ __________ (2w) solutions low content in K+ content (≤5 mEq/L),
After initial blood volume restoration with physiologic saline or isotonic crystalloid hypertonic saline may be infused to correct the Na+ (and Cl−) deficit
At Na+ concentrations less than _____ mEq/L seizures frequently occur
At Na+ concentrations less than 110 mEq/L seizures frequently occur
Na+ deficit [in mEq] can be calculated as:
(normal serum Na+ [in mEq/L] − measured serum Na+ [in mEq/L]) × 0.4 body weight in kg
in the situations of a life-threatening metabolic acidosis (pH <7.2) administration of
in the situations of a life-threatening metabolic acidosis (pH <7.2) administration of sodium bicarbonate (Na+HCO3−) may become necessary.
The required dose of NaHCO3 is calculated based on the formula:
(-BE): -BE [in mEq/L] × 0.4 × body weight in kg
How do administer sodium bicarbonate? can you give total dose?
No, one half of the calculated bicarbonate dose should be administered first over 20 to 30 minutes and then a blood gas analysis repeated to assess the effect before the second half of the dose is
administere
There is one drug contra-indicated in uroperitoneum cases. which one? why?
Use of α2-agonists (e.g., xylazine) should be avoided because of their respiratory depressant-, proarrhythmogenic- and diuresis-promoting properties
The most common life-threatening arrhythmia observed in foals with uremia and hyperkalemia is
third degree atrioventricular block
hyponatremia in uroperitoneum cases should corrected slowly to avoid what pathology?
central pontine myelinosis
third-degree AV block, may be precipitated by
surgical stimulation
third-degree AV block, how to treat?
administration of atropine at higher than usual doses (i.e., 20–40 μg/kg IV) and/or ephedrine (25–50 μg/kg IV) may resolve the arrhythmia. If not effective, epinephrine (10–20 μg/kg IV) and closed chest massage must be initiated.
most frequently encountered abdominal diseases requiring an emergency laparotomy in young foals
Strangulated inguinal hernia, persistent meconium impaction, intestinal intussusception, and intestinal volvulus
rib fractures may account for as many as __7% of life-threatening fractures in foals younger than 6 months of age
37%
The fractures occur most commonly at the ___________ (2w) or the area immediately above it and are best detected with _______________ (1w).
The fractures occur most commonly at the costochondral junction or the area immediately above it and are best detected with ultrasonography.
Typically _______ or more ribs are affected, with those on the ______side of the chest (______ to eighth) most frequently involved.
Typically three or more ribs are affected, with those on the left side of the chest (third to eighth) most frequently involved.
Typical complications (5) of dislocation of fractured ribs
hemothorax
pneumothorax
pulmonary laceration
acute parenchymal lung injury
Atelectasis formation
pleuritis
Clinical signs (8) fx ribs commonly include
tachycardia, tachypnea, or respiratory distress because of pain and impaired pulmonary gas exchange causing hypoxemia and hypercapnia, subcutaneous emphysema, chest pain, anemia and hypovolemia if blood loss was significant, and mental depression
Preanesthetic emergency care of the foal with compromising thoracic trauma 5 things
nasal insufflation of O2 (5–
10 L/min), IV fluid therapy with isotonic polyionic crystalloid solutions for circulatory volume replacement plus fresh frozen plasma or fresh whole blood for supplementation of red blood cells, coagulation factors and platelets when indicated, thoracocentesis to evacuate the chest in case of pneumothorax or hemothorax, and appropriate antiinflammatory and analgesic treatment (e.g., flunixin meglumine, methadone, butorphanol, lidocaine infusion)
ketamine is the preferred induction agent over propofol and alfaxalone in this patient group, why?
propofol and alfaxalone are more likely producing apnea upon induction of anesthesia
Say the protocol of sedation and induction in case of thoracic trauma
Midazolam 0.2 mg/kg and butorphanol 0.2-0.3 mg/kg
ketamine 1-2 mg/kg
if the foal remains markedly hypercapnic (PaCO2 >65 mm Hg) and hypoxemic (PaO2 <55–60 mm Hg; SpO2 <85%) what type of ventilation should be used?
Volume-limited positive pressure ventilation with or without positive end-expiratory pressure (PEEP)
Tidal volume 4-6 mL/kg
