Emergency critical care 2 AI Flashcards
1
Q
When can clinical signs of anticoagulant rodenticide toxicity occur?
A
Up to 2-7 days post ingestion.
2
Q
What should be determined if possible in cases of anticoagulant rodenticide toxicity?
A
The type of toxin ingested.
3
Q
What is the preferred route of administration for continuous rate infusion (CRI) therapy?
A
Intravenous
4
Q
What are the advantages of CRI administration over bolus therapy for hypercalcaemia?
A
Better diuresis and calciuresis
5
Q
How can sodium bicarbonate be used in the management of an acute hypercalcaemic crisis?
A
To produce alkalosis and reduce serum ionized calcium levels
6
Q
What are the effects of steroids on hypercalcaemia?
A
Enhance renal excretion, reduce intestinal uptake, and decrease bone absorption
7
Q
What are the possible differential diagnoses for hypercalcaemia?
A
Hyperparathyroidism, Addison’s disease, renal failure, vitamin D toxicity, idiopathic or infectious disease, osteolysis, neoplasia, and spurious causes
8
Q
What is the absolute requirement for glucose in the body?
A
The brain has an absolute requirement for glucose
9
Q
What causes insulin to be released by the pancreas?
A
In response to elevated serum glucose, amino acids, and gastrointestinal hormones
10
Q
What are the functions of insulin in glucose metabolism?
A
Encourages hepatic glycogen and fatty acid production, inhibits glucose production and glycogen breakdown
11
Q
How is glucose stored in the body?
A
As glycogen, mainly in the liver
12
Q
What are the clinical signs of hypoglycaemia?
A
Behavioural changes, ataxia, and seizures
13
Q
What is the treatment for hypoglycaemia causing neurological signs?
A
Parenteral glucose administration
14
Q
How can glucose be administered for hypoglycaemia treatment?
A
As a bolus (0.5g/kg i/v) or through a CRI of glucose-containing fluids
15
Q
What is the recommended solution concentration for glucose administration?
A
2.5-10% glucose saline
16
Q
What should be done if an insulinoma is suspected in hypoglycaemia treatment?
A
Avoid rapidly giving glucose boluses, consider frequent feeding and glucagon infusions instead
17
Q
What are the possible differential diagnoses for hypoglycaemia?
A
Excess insulin, growth hormone deficiency, cortisol deficiency, glucagon deficiency, hepatic disease, vascular disease, increased substrate use, fasting hypoglycaemia in pregnancy, neonatal, juvenile, or toy dog hypoglycaemia, insulin overdose, prolonged blood storage, portable analyser error
18
Q
What are the possible causes of marked hyperglycaemia?
A
Diabetes mellitus or stress in cats
19
Q
How can mild hyperglycaemia be differentiated from stress in cats?
A
Serial blood glucose measurements, serum fructosamine concentrations, or home urine samples
20
Q
What are some drugs used for management of post-resuscitation ventricular tachycardia?
A
Lidocaine and specific anaesthetic antagonists
21
Q
What is the use of sodium bicarbonate during resuscitation?
A
It is used for severe metabolic acidosis
22
Q
What is recommended for arterial blood flow maintenance after restoring heart rate and rhythm?
A
Dopamine
23
Q
Why should aggressive fluid therapy be avoided during CPCR?
A
Excessive fluid administration can result in decreased coronary and cerebral perfusion
24
Q
When is fluid therapy usually given during CPCR?
A
If the animal was hypovolaemic prior to the CPA
25
What is the routine technique for monitoring forward blood flow during CPCR?
Palpation of the femoral pulse
26
What can be misleading about palpation of the femoral pulse?
Compression can generate venous pulses due to backflow of blood in the caudal vena cava
27
What is the significance of retinal blood flow during resuscitation?
If retinal blood flow is present, it suggests adequate cerebral perfusion should be present
28
What are some signs of effective circulation that should be monitored during CPCR?
Improvement in mucous membrane color, reduction in capillary refill time, and reduction in pupil size
29
Why should pulse oximetry be avoided during CPCR?
Pulsatile blood flow is usually inadequate
30
What information does measurement of ETCO2 with a capnograph provide during CPCR?
It reflects the success of ventilation in moving CO2 from peripheral tissues to the lungs
31
What does a reliable trace of ETCO2 suggest during resuscitation?
It is a good indicator of successful perfusion
32
Should ventilation cease immediately on return of spontaneous respiration?
No, it should continue as required until the patient regains consciousness
33
What complications should be avoided during post-resuscitation monitoring?
Pulmonary edema, renal failure, and disseminated intravascular coagulation
34
What neurological abnormalities can be expected after CPA?
Blindness and proprioceptive deficits
35
Should glucocorticoids be administered to patients with neurological abnormalities after CPA?
No, as they may worsen outcomes by causing hyperglycemia
36
What is the normal anion gap in dogs?
Approximately 8-25 mEq/l
37
What is the normal anion gap in cats?
Approximately 10-27 mEq/l
38
What does the anion gap reflect?
The difference in measurable anions and cations
39
What are the main contributors to the anion gap?
Plasma proteins, lactate, and ketones
40
What causes normochloraemic high anion gap acidosis?
Accumulation of inorganic ions, diabetic ketoacidosis, uraemia, lactic acidosis, certain toxins
41
What causes hyperchloraemic or normal anion gap acidosis?
Diarrhoea, renal tubular acidosis, carbonic anhydrase inhibitors, acidifying agents
42
How does hypoalbuminaemia affect the anion gap?
Reduces the anion gap, decrease by 3mEq/l for every 10g/l decrease in albumin concentration
43
What is the strong ion difference (SID)?
The difference between sodium and chloride, approximately 36-38mEq/l in dogs and cats
44
What does an increase in SID indicate?
Hypochloraemia and metabolic alkalosis
45
What does a decrease in SID indicate?
Hyperchloremic acidosis
46
How can strong ion difference be estimated?
[Na+] - [Cl-]
47
How is strong ion difference used in assessing mixed acid-base disorders?
In combination with the anion gap
48
How can arterial samples be used for evaluation?
To evaluate respiratory function (PCO3 / PO2)
49
How can venous samples be used for evaluation?
To evaluate acid-base balance
50
What pH range is considered normal in patients?
pH 7.35-7.45
51
What are the criteria for metabolic acidosis?
HCO3 < 20mmol/l or BE <-4mEq/l
52
What are the criteria for metabolic alkalosis?
HCO3 > 24mmol/l or BE > 4mEq/l
53
What are some causes of hyperglycemia?
Diabetes Mellitus, Stress, Postprandial, Hyperadrenocorticism, Pheochromocytoma, Dioestrus, Acromegaly, Head trauma, Drugs
54
What happens in diabetes due to a lack of insulin?
Impaired glucose storage, utilization, and uptake
55
What is the alternative energy source when there is a lack of available energy in diabetes?
Fat
56
What are fatty acids oxidized into in the liver under the control of glucagon?
Ketone bodies
57
What is the result when ketone body production in diabetes outstrips utilization?
Acidosis ketosis
58
What is one of the most common endocrine emergencies in veterinary patients?
Diabetic ketoacidosis
59
What is the mortality rate of diabetic ketoacidosis in people?
5-10%
60
What should be considered if there are limited facilities or complicating factors in managing diabetic ketoacidosis?
Referral
61
What neurological signs are seen in hyperosmolar, non-ketotic diabetes?
Increased serum osmolality, treated similarly to DKA
62
What is the role of magnesium in cellular mechanisms?
Essential cofactor for Na/K ATPase and NMDA receptor
63
What can hypomagnesemia lead to?
Refractory hypokalemia
64
At what rate is magnesium supplementation given?
0.01-0.04 mmol magnesium/kg/hour
65
What should be considered for faster fluid administration and sampling during stabilization in diabetic ketoacidosis?
A central line
66
How can serum ketones be measured?
By placing serum onto a urine dipstick
67
What is the recommended fluid for volume resuscitation in diabetic ketoacidosis?
0.9% NaCl or Hartmann's solution
68
What is the suggested volume for fluid boluses in diabetic ketoacidosis?
10ml/kg given over 10-20 minutes
69
When can insulin therapy be initiated in diabetic ketoacidosis?
Once volume resuscitation is complete
70
What does the Base Balance (BE) measure?
Base Balance (BE) provides a quantitative estimation of surplus acid or base.
71
What does a positive Base Balance (BE) value indicate?
Positive BE values reflect an excess of base or deficit of acid.
72
What is the normal value of Base Balance (BE) for a neutral environment?
A normal animal should have a BE value of zero.
73
How is Base Balance (BE) defined?
BE is the amount of strong acid required to titrate 1L of blood to a pH of 7.4 at 37°C.
74
What does Base Excess < -4 mEq/l or HCO3 < 20mmol/l indicate?
Base Excess < -4 mEq/l or HCO3 < 20mmol/l reflects metabolic acidosis.
75
What are common causes of metabolic acidosis?
Common causes include gain of acid (e.g. diabetic ketoacidosis), lactic acidosis, toxins, renal failure, and loss of bicarbonate.
76
What does Base Excess >4mEq/l or HCO3 >24mmol/l indicate?
Base Excess >4mEq/l or HCO3 >24mmol/l reflect metabolic alkalosis.
77
What are common causes of metabolic alkalosis?
Common causes include acute profuse vomiting, excessive use of diuretics, pyloric outflow obstruction, and bicarbonate therapy.
78
What does PaO2 measure?
PaO2 is the partial pressure of oxygen dissolved in arterial blood.
79
What is the normal range for PaO2 at sea level?
The normal range for PaO2 is 90-100mmHg at sea level, breathing room air.
80
How does altitude affect PaO2?
Altitude results in 'normally' lower PaO2 values, with compensatory increases in red blood cells.
81
What PaO2 value is considered hypoxia?
PaO2 < 80mmHg is considered hypoxia.
82
How is the Alveolar-Arterial O2 Difference (A-a Gradient) calculated?
A-a gradient = PAO2 - PaO2
83
What does the Alveolar-Arterial O2 Difference (A-a Gradient) measure?
The A-a Gradient measures the difference in O2 tension between the alveolus and artery, providing information about lung function.
84
What are the normal values for the A-a gradient?
Normal values for the A-a gradient are 5-15 mmHg.
85
What does O2 saturation (SaO2) measure?
O2 saturation (SaO2) measures the percentage of O2 bound to hemoglobin.
86
What is considered a normal value for O2 saturation (SaO2)?
SaO2 > 95% is considered normal.
87
What is the potential cause of pulseless electrical activity (PEA)?
Anaesthetic overdose, acute hypoxia, acidosis, toxicity, and cardiogenic shock
88
What are the potential causes of ventricular fibrillation?
Unknown in small animals, but common in humans
89
How can ventricular fibrillation be distinguished from PEA?
By observation of an ECG
90
What is the recommended treatment for PEA?
Cardiopulmonary resuscitation (CPCR) and adrenaline
91
What is the recommended treatment for ventricular fibrillation?
Defibrillation with a defibrillator or mechanical defibrillation
92
Which route offers the quickest access to the central circulation for drug administration?
Central venous access
93
What should be done after administering drugs through peripheral venous access?
Followed by a large volume flush to move the drug into the central circulation
94
What is the recommended replacement interval for drawn-up drugs in syringes?
Every 2-4 weeks
95
What are the effects of adrenaline on α-adrenergic receptors?
Peripheral vasoconstriction, increased blood pressure, and blood flow to the head
96
What are the effects of adrenaline on β-adrenergic receptors?
Increased heart rate and contractility
97
What is the risk associated with high dose adrenaline?
Increased myocardial oxygen demand
98
When is low dose adrenaline suggested as the initial treatment?
In the first instance, moving to high doses if there is no response
99
Which drug is recommended to treat sinus bradycardia, 3rd degree AV block, or increased vagal tone?
Atropine
100
What is the caution advised with atropine dosing?
Can cause marked rebound tachycardia, increasing myocardial oxygen demand
101
What are some other useful drugs in specific circumstances?
Not mentioned in the course notes
102
What action is required to determine the cause of thoracic disease stopping chest expansion?
Thoracic auscultation +/- thoracocentesis
103
What are the potential complications of over forceful ventilation?
Lungs barotrauma, haemorrhage, and pneumothorax
104
What are the potential consequences of rapid ventilation causing hypocapnia?
Reduced cerebral perfusion
105
What are the potential consequences of prolonged long inspiratory times?
Increased intrathoracic pressure reducing venous return
106
What can be done if spontaneous ventilation resumes during CPR?
A full CPA may have been avoided
107
What acupuncture point can be considered in a respiratory arrest?
Jen Chung (GV26)
108
Where should a hypodermic needle be inserted during acupuncture of GV26?
Mid-line of the nasal philtrum below the nares
109
What should be avoided as a reversal agent for drugs that cause apnea?
Doxapram
110
Why should doxapram be avoided?
It decreases cerebral blood flow and leads to increased oxygen requirements
111
What is an essential component of successful CPR?
Effective chest compressions
112
What is the aim of chest compressions in terms of chest wall compression?
At least 25-33% compression
113
What is the recommended compression rate during CPR?
80-120 compressions per minute
114
Should compressions be continued during ventilation?
Yes
115
What technique is suggested for performing chest compressions in cats and small dogs?
Cardiac pump technique
116
What technique is recommended for larger dogs or when the cardiac pump technique is ineffective?
Thoracic pump technique
117
When should open-chest CPR be considered?
In larger dogs (>20kg) or animals with pleural space disease, pericardial effusion, or chest wall trauma
118
What is performed during open-chest CPR in order to directly compress the heart?
Rapid left sided lateral thoracotomy
119
What can be considered to direct forward blood flow to the brain during open-chest CPCR?
Cross clamping the aorta
120
What should be done after successful open-chest CPCR?
Thoroughly lavage the chest, collect samples for culture, and close the incision aseptically
121
What should be placed as soon as possible after CPR to identify the underlying arrest rhythm?
ECG
122
What are the most common arrest rhythms in small animals?
Asystole and PEA (Pulseless Electrical Activity)
123
What is the recommended treatment for asystole?
Aggressive CPR and adrenaline
124
What is pulseless electrical activity (PEA) previously known as?
Electromechanical dissociation (EMD)
125
What are the learning objectives of this module?
The learning objectives include understanding emergency data bases, electrolyte abnormalities, acid base analysis, and cardiopulmonary resuscitation.
126
What is the purpose of an initial laboratory database in emergency medicine?
The initial laboratory database is used to assess PCV/TS, buffy coat, total solids, blood smear, and platelet counts.
127
How is PCV/TS measured and what does it indicate?
PCV/TS is measured on a microhaematocrit centrifuge and indicates the level of white blood cells and total proteins in the blood.
128
What is the normal range for total solids (TS) and what does it signify?
The normal range for TS is 60-80g/l (or 6-8g/dL) and it provides an estimation of total proteins in untreated patients.
129
How can jaundice and haemolysis be assessed using the laboratory database?
Jaundice can be assessed by visually examining the serum color, and haemolysis can be detected through the buffy coat and blood smear analysis.
130
Why is it important to make a smear at the time of blood sampling?
Making a smear at the time of blood sampling allows for further assessment of anaemia, white cell numbers, platelet numbers, and morphology.
131
Why is manual evaluation of platelet counts essential?
Platelets may clump easily and not be counted correctly during automated counting, requiring manual evaluation for accurate platelet numbers.
132
What is the significance of breed variation in platelet counts?
Certain breeds like greyhounds have lower normal platelet counts, while Cavalier King Charles Spaniels have circulating macrothrombocytes.
133
What is the recommended anticoagulant to prevent platelet clumping during counting?
Citrate anticoagulant is recommended if platelet clumping is a consistent problem during counting.
134
What tools are needed to evaluate a blood smear in-house?
Evaluating a blood smear in-house requires a practice microscope and appropriate stains.
135
When should a blood smear be prepared?
A blood smear should be prepared as soon as possible after blood sampling.
136
What is the most common electrolyte abnormality in critically ill patients?
Hypokalemia
137
What are the clinical signs of hypokalemia?
Muscle weakness, cramping, and lethargy
138
What are the effects of hypokalemia on the gastrointestinal tract?
Ileus due to smooth muscle weakness
139
What are the effects of hypokalemia on the urinary system?
Urinary retention secondary to detrusor muscle atony
140
What cardiac abnormalities may occur with hypokalemia?
Prolongation of the QT interval and arrhythmias
141
How can hypokalemia lead to metabolic acidosis?
Chronic hypokalemia may lead to defective renal tubular acidification
142
What is the treatment for hypokalemia?
Treating the underlying cause and improving serum potassium levels through infusion
143
What is the maximum rate of intravenous infusion for potassium in hypokalemia treatment?
0.5mmol/kg/hour
144
What other electrolyte may need supplementation if hypophosphatemia is present?
Potassium phosphate
145
What is the recommended oral supplementation for long-term treatment of hypokalemia?
Potassium gluconate of 2-6 mmol/l/cat/day
146
What are the possible causes of hypokalemia due to decreased intake?
Anorexia and potassium deficient IVFT
147
What are the possible causes of hypokalemia due to translocation?
Alkalosis, insulin/glucose-containing fluids, and catecholamine β-agonist overdosage
148
What are the possible causes of hypokalemia due to increased loss?
GIT loss (vomiting or diarrhea) or renal loss (chronic renal failure, renal tubular acidosis, mineralocorticoid excess, drugs)
149
What are the causes of hyperkalemia?
Increased intake, decreased excretion, or translocation out of cells
150
What are the life-threatening consequences of hyperkalemia?
Change in cardiac resting membrane potential leading to bradycardia, widened QRS complexes, ventricular fibrillation, and cardiac arrest
151
How can the effects of hyperkalemia on cardiac output be reduced in the emergency situation?
By increasing the difference between the resting potential and threshold with increased serum calcium concentrations
152
What is the treatment for hyperkalemia?
Treating the underlying cause and reducing the hyperkalemia and its effects
153
What can be used to increase the difference between the resting potential and threshold in the emergency treatment of hyperkalemia?
Calcium gluconate
154
What are the clinical signs of hypernatraemia?
Dullness, lethargy, anorexia, coma, seizures.
155
At what serum sodium level do neurological signs usually appear?
When serum sodium levels exceed 170mmol/l.
156
What are idiogenic osmoles?
Osmotically active osmoles produced by the brain to balance the increase in plasma osmolarity.
157
What is the suggested rate of sodium reduction when treating hypernatraemia?
No greater than 0.5mol/l/hour.
158
How long will it take to reduce a serum sodium of 200mol/l to normal (150mmol/l)?
100 hours i.e. 4 days.
159
What fluid is usually used for volume resuscitation in hypernatraemia?
0.9% sodium chloride.
160
What fluid may be used if solute gain has occurred in hypernatraemia?
5% glucose.
161
How does frusemide help in hypernatraemia?
It helps spread sodium excretion by enhancing it by loss by approximately 17 times.
162
What are the differential diagnoses for hypernatraemia?
Pure water deficit, primary hypodipsia, diabetes insipidus, high environmental temperature, hypotonic fluid loss, osmotic diuresis, renal failure, impermeant solute gain, salt poisoning, hypertonic fluid administration, hyperaldosteronism, hyperadrenocorticism.
163
What is the equation used to predict the effects of infusing various fluids?
Change in serum Sodium = Infusate [Na+] - Serum [Na+] / [Body weight (kg) x 0.6] + 1.
164
How long is the recommended treatment for Coumarin (warfarin) products?
7 days
165
What is the recommended treatment duration for Indanediones?
3-4 weeks
166
Which generation of compounds has the longest half-lives?
Second generation
167
Where can screens for rodenticides be performed?
Nutristasis Unit of Guys and St Thomas’s Hospital, London
168
How can falsely negative samples be avoided for rodenticide testing?
Samples taken in the early stages of the disease
169
What can be measured to support exposure to anticoagulant rodenticides?
Vitamin K1 and Vitamin K1 reductase
170
What can be administered to stop significant absorption of rodenticides?
Activated charcoal
171
How long are animals treated with oral vitamin K for after rodenticide ingestion?
7 days
172
When is i/m dosing of Vitamin K1 recommended?
Initially, as absorption is rapid
173
What should be done if clotting factors are diluted further during volume resuscitation?
Consider colloids
174
What should be done if local bleeding occurs during rodenticide treatment?
Control local bleeding with pressure, surgery, packs, or phenylephrine
175
How should Vitamin K be administered to avoid haematoma formation?
Given in several small doses with a fine needle
176
How long is the suggested treatment duration if the toxin ingested is unknown?
4-6 weeks
177
What can be done to improve vitamin K absorption?
A fatty meal
178
When should PT be rechecked after the last dose of Vitamin K?
48 hours
179
How long should treatment be continued if PT remains elevated after the initial treatment?
2 weeks
180
What is the main intracellular cation?
Potassium
181
Which tissues are affected by disruption to normal potassium levels?
Heart, muscles, and nerves
182
Where are serum potassium levels controlled?
By the kidneys
183
What is the normal range for serum potassium levels?
3.5-5 mmol/l
184
Why are serum potassium levels elevated compared to plasma samples?
Potassium released during the clotting process
185
What can increase blood potassium levels?
Thrombocytosis
186
Which animals have similar concentrations of potassium in their red cells and plasma?
Adult feline and canine
187
What can cause elevated potassium concentrations in serum?
Haemolysis
188
How are potassium concentrations controlled within red cells?
By sodium potassium ATPase activity
189
Which breed may genetically lack membrane sodium potassium ATPase activity?
Shiba Inu
190
What are the possible respiratory acid-base disorders?
Respiratory acidosis (PCO2 > 45mmHg) and respiratory alkalosis (PCO2 < 35mmHg)
191
What is the compensatory mechanism for primary base disorders?
Changes in either the respiratory or metabolic compartments induce a compensatory change in the opposite compartment
192
How quickly can the lungs compensate for changes?
Lungs can compensate within minutes by altering minute volume
193
When does renal compensation typically start?
Renal compensation starts after a few hours and has maximal effect at 4-5 days
194
What does the presence or absence of compensation indicate?
Presence of compensation indicates chronicity while absence suggests a mixed disorder
195
How can we evaluate oxygenation?
Arterial PO2 should be approximately 5 times the inspired O2 concentration (FiO2)
196
What does venous PO2 provide information about?
Venous PO2 gives information about oxygen extraction by the tissues and delivery adequacy
197
What is the purpose of cardiopulmonary resuscitation (CPR)?
To provide circulatory and respiratory support and produce the return of spontaneous circulation
198
What are the two categories of patients in cardiac arrest studies?
Irreversible cases (end-stage disease) and reversible causes (anaesthetic overdoses, electrolyte imbalances)
199
What is essential for successful CPR?
Good preparation, teamwork, and access to necessary equipment
200
How many team members are needed to perform effective CPR?
At least three team members
201
What is the recommended duration for chest compressions before changing operators?
2-3 minutes
202
What should be done when an arrest is discovered?
Move the animal onto a suitable firm surface in a well-lit and accessible area
203
What should be included in a well-stocked crash box?
Endotracheal tubes, laryngoscope, gauze bandage, ambubag, intravenous catheters, tape, needles, syringes, urinary catheters
204
Can effective CPCR be performed alone?
No, but chest compressions alone may prevent short-term hypoxia until help arrives
205
What are some drugs that should be included in the tracheal drug administration kit?
Adrenaline, atropine, lignocaine
206
What is the purpose of administering oxygen during CPR?
To assist and improve ventilation
207
What is a relatively common cause of cardiopulmonary arrest in veterinary medicine?
Vasovagal syncope
208
How can vasovagal syncope be treated to prevent cardiac arrest?
Timely treatment with low-dose atropine
209
What does basic life support consist of?
Establishing airway, providing positive pressure ventilation, generating effective circulation
210
What is the first priority in basic life support?
Establishing a patent airway
211
How can correct endotracheal tube placement be confirmed?
By visualisation, cervical palpation, appropriate chest wall excursion
212
What is the ideal way to provide positive pressure ventilation?
Using an Ambu bag with 100% oxygen
213
What ventilatory rate is appropriate for most patients during CPR?
8-12 breaths/minute
214
What should be observed during positive pressure ventilation?
Normal degree of chest excursion with even inflation and relaxation
215
What is the loading dose of insulin for i/m protocol?
0.2 IU/kg.
216
How frequently should the i/m dose be decreased?
Every hour.
217
What is the recommended dose of neutral insulin for subcutaneous injections?
6 hourly.
218
How often should blood glucose concentrations be measured?
Every 1-2 hours.
219
What is the suggested supplementation if blood glucose is less than 12 mmol/l?
2.5% glucose solution.
220
How much 50% glucose should be added to a 500ml bag if blood glucose is less than 12 mmol/l?
25ml.
221
When should lente insulin be commenced?
Once the patient is eating and ketonuria has resolved.
222
What is the rate of intravenous infusion for potassium supplementation?
Not exceed 0.5mmol/kg/hour.
223
How much KCl should be added to 250ml 0.9% NaCl if serum potassium is less than 2 mmol/l?
20 mmol.
224
What is the gold standard for assessment of respiratory function?
Arterial blood gas analysis.
225
What is the recommended anti-coagulant for arterial blood samples?
Heparin.
226
Where are arterial blood samples commonly taken from?
Dorsal pedal artery.
227
How long should samples be stored before running the analysis?
As quickly as possible.
228
What significant changes in PO2 occur after 12 minutes at room temperature?
Significant changes.
229
What changes occur in acid-base balance after 30 minutes at room temperature?
Significant changes.
230
What are the three forms of calcium in the extracellular space?
Ionized calcium, protein-bound calcium, and complexed calcium
231
Which form of calcium more accurately reflects biologically active calcium?
Ionized calcium
232
How can changes in serum proteins affect serum total calcium levels?
Changes in serum proteins can markedly change serum total calcium levels
233
How does pH affect the proportion of bound calcium without altering the total amount present?
Changes in pH can change the proportion of bound calcium without altering the total amount present
234
What is the normal reference interval for ionized calcium?
The normal reference interval for ionized calcium is usually around 1.1 to 1.4 mmol/l
235
At what calcium concentration do clinical signs of hypocalcaemia usually present?
Clinical signs of hypocalcaemia usually present at calcium concentrations below 2mmol/l
236
What are some initial clinical signs of hypocalcaemia?
Initial clinical signs can be subtle e.g. fascial irritation or prolapse of the 3rd eyelids
237
What are some signs of increased neuromuscular excitability related to hypocalcaemia?
Muscle twitching, stiffness, ataxia, and seizures are frequently seen signs of increased neuromuscular excitability related to hypocalcaemia
238
What can result from increased muscle activity in hypocalcaemia?
Hyperthermia can result from increased muscle activity in hypocalcaemia
239
What are some cardiac manifestations of hypocalcaemia?
Tachyarrhythmias, a prolonged Q-T interval, and hypotension are cardiac manifestations of hypocalcaemia
