Anaesthetics and Intensive Care Medicine (Quesmed) Flashcards
What are the 7 causes of Airway Compromise?
Angioedema
Anaphylaxis
Thermal injury
Neck Haematoma
Wheeze
Surgical Emphysema
Reduced Consciousness
What is the 4 step approach to Assessing a C-Spine Injury?
ABCDE Approach
Full Mobilisation until C-Spine is Cleared
Detailed History and Examination
Imaging as required
What are the 5 NEXUS Criteria needed to determine whether a C-Spine Injury is unlikely?
Normal Level of Alertness
No Evidence of Intoxication
No Painful Distracting Injury
No Focal Neurological Injury
Absence of Midline Cervical Tenderness
If all of the above Criteria are met, C-Spine may be cleared and Imaging may not be required
If the C-Spine cannot be cleared clinically, proceed with Imaging (CT, not plain Xrays as Xrays have limited value here)
What is the 4 step management of a C-Spine Injury?
Airway management while in full in-line Stabilisation
(Maintain Neutral Neck Position- Do Not use Head Tilt/ Chin Lift Manouevre. Instead use aa Jaw Thrust if Required)
Application of an Appropriately Sized Semi-rigid Collar
Secure Head with Blocks and Tape
Secure patient with full in-line Stabilisation
What signs after a surgery are considered abnormal?
Hypotension and Tachycardia are considered abnormal and are a sign of Shock, which may be due to a post-operative bleed
A Mild Pyrexia is common in the 48 hours after a Procedure
What are the 4 signs of a Cluster Headache?
A Unilateral headache that is typically worse around the Eye- occuring in Clusters over time
A Bloodshot or Teary Eye
Vomiting
Rhinorrhoea
What are the 2 Risk Factors for a Cluster Headache?
Middle Aged Men
Alcohol and Smoking
What is the 2 (2,2) step management of a Cluster Headache?
Treatment of a Cluster Headache is with 100% Oxygen and Sumatriptan
Prophylactic Treatment includes Verapamil and Steroids
What is Compartment Syndrome?
It most commonly develops after Limb Trauma where Muscle Swelling and Inflammation leads to an Increase in Pressure in the Muscle Compartment
This is a limb-threatening condition that needs to be diagnosed and treated quickly as the increase in pressure can cause a Loss of the Blood Supply to that Limb and Subsequent Ischaemia
What are the 5 signs of Compartment Syndrome?
Severe Pain, particularly on the Passive Flexion of the Toes
Pallor
Paralysis of the Limb
Pulselessness
Paraesthesia
What is the 3 step management of Compartment Syndrome?
Urgent Fasciotomy
Analgesia
Fluids
What is Delirium tremens?
It is a rapid onset of Confusion Precipitated by Alcohol Withdrawal. It usually develops 72 hours after Ceasing Alcohol Intake and can last for several days
What are the 5 signs of Delirium tremens?
Confusion
Hallucinations (visual and tactile (such as Formication- sensation of Insects crawling on or under the skin))
Sweating
Hypertension
(Rare) Seizures
What is the 5 step management of Delirium tremens?
Chlordiazepoxide
Fluids
Anti-emetics
Pabrinex
Refer to Local Drug and Alcohol Liaison Team
What 7 drugs should be stopped before a Surgery? And how long should they be stopped for?
- Clopidogrel should be stopped 7 days before the surgery
- Warfarin should be stopped 5 days before the surgery and patients should be on Low Molecular Weight Heparins instead until the Night before
- ACE Inhibitors should be stopped the day before
- Insulin should be held on the day of the surgery (only the short-acting preparations)
- Sulfonylureas should be held on the day of the surgery (due to the risk of Hypoglycaemia)
- Metformin can be given as normal for Short Procedures. For Longer Procedures, where patients are not Eating or Drinking for several days, Metformin should be held and Variable-rate Insulin should be Prescribed
- The Pill should be stopped 4-6 weeks before Surgery and restarted at least 2 weeks after Surgery. This reduces the Risk of Deep Vein Thrombosis (DVT)
What is Epidural Anesthesia (where is it injected)? What are the 3 risks? And how is it monitored?
It is the injection of a Local Anaesthetic to the Epidural Space around L2-3 or L3-4 at the Vertebral Level
3 Risks-
- Maternal hypotension, which results in Foetal and Maternal Distress
- Risk of Dural Puncture (which results in a severe Postural Headache)
- Epidural Haematoma
Monitoring-
- CTG (Cardiotocography) monitoring of the foetus’ heart rate is recommended.
What are the 7 signs that suggest a patient may require fluid resuscitation?
Systolic BP<100mmHg
Heart Rate >90bpm
Capillary Refill>2s
Cool Peripheries
Respiratory Rate>20
NEWS>/=5
Dry Mucous Membranes
What is the 4 step approach to Fluid Resuscitation?
Identify the cause of Fluid Deficit and respond appropriately
Fluid bolus of 500ml Crystalloid over<15 minutes
Reassess using ABCDE Approach
Further Fluid Boluses (up to 2,000ml) may be required
What are the 5 daily fluid requirements?
25-30mL/kg/ day of Water
1 mmol/kg/day of Sodium
1 mmol/kg/day of Potassium
1 mmol/kg/day of Chloride
50-100g/ day of Glucose to limit Ketosis
What are Crystalloid and Colloid Fluids?
Crystalloid Fluid- Solution containing small molecules (Sodium, Chloride)
Colloid Fluid- Solution containing larger molecules (Albumin)
What is the composition of 0.9% Sodium Chloride (Saline) Fluid, 0.18% Sodium Chloride/ 4% Glucose, 0.45% Sodium Chloride/ 4% Glucose, 5% Dextrose and Hartmann’s?
0.9% Sodium Chloride-
- 154mmol/L of Sodium and 154%mmol/L of Chloride
0.18% Sodium Chloride/ 4% Glucose-
- 31mmol/L of Sodium, 31mmol/L of Chloride and 222mmol/L Glucose
0.45% of Sodium Chloride/ 4% Glucose-
- 77mmol/L of Sodium, 77mool/L of Chloride and 222mmol/L Glucose
5% Dextrose-
- 278mmol/L Glucose
Hartmann’s-
- 131mmol/L of Sodium, 5mmol/L of Potassium, 111mmol/L of Chloride and 29mmol/L of HCO3-
What are the 4 types of Fluid suitable for Resuscitation and which 2 should not be used for Resuscitation and why?
Suitable
- Saline (0.9% NaCl)
- Hartmann’s Solution
- 4-5% Human Albumin Solution- if Severe Sepsis
- Blood- if Severe Haemorrhage
Fluids not suitable for Resuscitation-
- Dextrose (Does not stay in the Intravascular Compartment)
- Gelofusine (Risk of Anaphylaxis)
What is the 4 step approach to using Fluids to Resuscitate patients?
Use 500ml of the Fluid of Choice, or 250ml if Cardiac Disease or if the patient is Old (due to the Increased Risk of Pulmonary Oedema secondary to Excessive Fluid Resuscitation)
This should be given over <15 minutes
This can be repeated if Needed
If the patient fails to respond after 2L of Fluid, they should be considered Non-Fluid Responsive and immediate help should be sought (they may require Blood Pressure Support)
What is Lactic Acidosis seen as in an ABG?
Raised Anion Gap, Metabolic Acidosis
What are the 7 causes of Type A (Tissue Hypoxia) and 5 causes of Type B (Abnormalities in the Metabolism of Lactate) Lactic Acidosis?
Type A-
- Shock
- Hypoxia
- Acute Mesenteric Ischaemia
- Limb Ischaemia
- Severe Anaemia
- Seizures
- Vigorous Exercise
Type B-
- Diabetic Ketoacidosis
- Cancer
- Liver Disease
- Inborn Errors in Metabolism
- Drugs (Metformin (impairs liver metabolism of Lactate) and Aspirin)
What are the 16 signs of Local Anaesthesia Toxicity?
Hypotension
Hypertension
Tachycardia
Sinus Bradycardia
Ventricular Arrhythmias
Asystole
Shivering
Tinnitus
Subtle Tremors of Face and Extremities
Restlessness and Agitation
Seizures
Numbness or Tingling around the Mouth
Vertigo and Dizziness
Decreased Consciousness
Respiratory Depression
Apnoea
What is the 5 step management of Local Anaesthesia Toxicity?
Stop administering the Local Anaesthetic
ABCDE approach including the ECG monitoring
Lipid Emulsion (20% Intralipid) 1ml/kg every 3 minutes up to a dose of 3mL/kg
Initiate Lipid Emulsion Infusion at a rate of 0.25ml/kg/min
Maximum Dose= 8ml/kg
What is the most common cause of Malignant Hyperthermia and what are the 2 triggers of this condition?
An Autosomal Dominant Mutation in the Ryanodine Receptor 1- which increases Calcium Levels in the Sarcoplasmic Reticulum and Increases Metabolic Rate- so it is Diagnosed by GENETIC Testing
Triggered by- Inhalation of Anaesthetics or Suxamethonium
How is Malignant Hyperthermia managed?
Stop the triggering agent
Administer Intravenous Dantrolene (Ryanodine Receptor Antagonist)
Restore Normothermia
What are the 8 signs of a Skull Fracture?
Subcutaneous Haematoma
Subcutaneous Haematoma around the eyes (Raccoon Eyes)
Subcutaneous Haematoma behind the ears (Battle Sign)
Subcutaneous Emphysema
CSF Rhinorrhoea
CSF Otorrhoea
Haemotympanum
Cranial Nerve Palsies- Arise 1-3 days after the Trauma
What is the first line investigation of Head Trauma and what 3 other investigations should be ordered?
CT Head
Other-
- CT Cervical Spine (look for Spinal Fractures)
- CT Angiogram (look for Local Vascular Injury)
- Plain Skull Xray (assess for Orbital Fracture)
What 2 interventions are contraindicated in a Skull Fracture?
Nasopharyngeal Airways (as this can cause further damage to the patient)
Head tilt Chin lift (contraindicated if patient is at risk of C-Spine Injury)
What is the pathophysiology of Medication Overuse Headaches?
Occurs due to the Down-regulation of Pain receptors-leading to the lack of efficacy of Analgesics when they are used
What are the 2 commonly used methods of confirming NG Tube placement?
1) Measuring the pH of the NG Tube Aspirate (Gastric Content has a pH of 1.5-3.5, so a pH less than 5 is enough to confirm Gastric Placement
2) Erect Chest Xray to confirm the NG Tube traverses inferiorly down the midline, bisects the Carina and the tip is below the Diaphragm. The tip should be 10cm below the gastrooesophageal junction
What is CPAP and BiPAP?
CPAP is a form of Noninvasive ventilation used in patients with Type 1 Respiratory Failure- providing Positive Pressure to keep the Alveoli open for a longer period of time to facilitate Gas Exchange
BiPAP is used in patients with Type 2 Respiratory Failures, with 2 different levels of Positive Pressure on Inspiration AND Expiration
What are the 3 Inclusion Criteria for starting Noninvasive Ventilation?
Patient awake and able to protect airway
Cooperative Patient
Consideration of Quality of Life of Patient
What are the 6 contraindications for starting Noninvasive Ventilation?
Facial burns
Vomiting
Untreated Pneumothorax
Severe Comorbidities
Haemodynamically unstable
Patient refusal
What are the 7 causes of Anaemia?
Iron Deficiency (most common)
Vitamin B12 or Folate Deficiency
Renal Failure
Malignancy
Menorrhagia
Anaemia of Chronic Disease
Drugs (chemotherapy agents)
What are the 5 pre-operative and 3 post-operative managements of Anaemia?
Preoperative management-
- Oral iron if >6 weeks until planned surgery
- IV iron if <6 weeks until planned surgery
- B12/Folate replacement
- Erythropoeisis-Stimulating Agent (ESA) Therapy
- Transfusion if Profound Anaemia and Surgery cannot be delayed
Postoperative management-
- Transfusion
- IV Iron
- Oral Iron
Why do patients on Steroids need their doses changed peri-operatively?
When the body experiences Acute Stress (illness, trauma and surgery), its steroid demand increases
Patients on long term steroids cannot respond to this demand as their adrenal function is suppressed
What is the 3 step peri-operative management of patients on steroids?
Switch Oral Steroids to 50-100mg IV Hydrocortisone
If there is an associated Hypotension, Fludrocortisone can be added
For minor operations, Oral Prednisolone can be restarted immediately post-operatively. If the surgery is major then they may require IV Hydrocortisone for up to 72 hours post-operatively
What is the 3 step Peri-operative management of Non-insulin Dependent Diabetics?
Hold all Oral Diabetic medications on the morning of the procedure
If the patient is on Insulin, switch to Sliding Scale Infusion (restart when they can eat)
Restart all Oral Medications the morning after surgery
For some operations, Metformin does not need to be stopped, but consider the risk of Lactic Acidosis
What is the 5 step Peri-operative management of Insulin-Dependent Diabetes?
Put the patient as early on the theatre list as possible to minimise the amount of time they are Nil By Mouth
If they are on Long-acting Insulin, continue this but at a reduced level (reduced by 20%)
Stop any other insulin and begin Sliding Scale Insulin Infusion from when the patient is Nil By Mouth
Continue Infusion until patient is able to eat Post-operatively
Switch to Normal Insulin Regimen around their First Meal
What are the 5 causes of Post-operative Nausea and Vomiting?
Infection
Hypovolaemia
Pain
Paralytic Ileus
Drugs
What are the 3 Non-pharmacological and 3 Pharmacological management approaches to Post-operative Nausea and Vomiting?
Non-pharmacological-
- Minimise patient movement
- Analgesia
- IV Fluids if Dehydrated
Pharmacological-
- 5HT3 Receptor Antagonist (Ondansetron- first line)- Risk of QT Prolongation and Constipation
- Histamine (H1) Receptor Antagonist (Cyclizine)- Avoid in Severe Heart Failure
- Dopamine (D2) Receptor Antagonist (Prochlorperazine)- Risk of Extrapyramidal Side Effects (Dystonic Reactions)
Other Antiemetics such as Corticosteroids and Metoclopramide are reserved for specific cases of Post-operative Nausea and Vomiting
What are the 3 Pre-renal, 1 Renal and 5 Post-renal causes of Poor Urine Output?
Pre-renal-
- Hypovolemia
- Hypotension
- Dehydration
Renal-
- Acute Tubular Necrosis
Post-renal-
- Benign Prostate Hypertrophy
- Anticholinergic or Alpha Adrenoceptor Antagonist Drugs (Commonly used in Anaesthetics)
- Pain (particularly Hernia Operations)
- Psychological Inhibition
- Opiate Analgesia
What is Rapid Sequence Induction?
It is the method of coordinating the administration of Rapid Acting Induction Agents to produce analgesia and muscle relaxation
Followed by Prompt Intubation, this results in a Secure Airway with a minimal risk of Aspiration
What are the 5 roles of Rapid Sequence Induction?
Airway
Drug Preparation
Monitoring of Vital Signs
Drug Administration
Cricoid Pressure
What are the 7 steps of Rapid Sequence Induction (7 Ps)
Preparation- Environment is optimised, Equipment is available, Staff are ready
Preoxygenation- Administration of high flow oxygen for 5 minutes before the procedure
Pretreatment- Administration of Opiate Analgesia or a Fluid Bolus to Counteract the Hypotensive effect of the Analgesia
Paralysis- Administration of the Induction Agent (Propofol or Sodium Thiopentone) and a Paralysing Agent (Suxamethonium or Recuronium)
Protection and Positioning (Cricoid Pressure should be applied following paralysis) In line Stabilisation may be required in some cases
Placement and Proof- Intubation is performed via Laryngoscopy with Proof Obtained (Direct Vision, End tidal CO2, Bilateral Auscultation)
Post-intubation Management- Taping or Tying the Endotracheal Tube, initiating mechanical ventilation and sedation agents
What is Suxamethonium Apnoea?
Occurs in people who have a defect in the Plasma Cholinesterase enzyme which normally breaks down Suxamethonium. These individuals have a prolonged period of paralysis following Suxamethonium Injection
How is Systemic Inflammatory Response Syndrome diagnosed?
More than one of:
- Temperature> 38C or <36C
- Heart Rate>90
- Respiratory Rate>20
- White Cell Count> 12 or <4
What is Sepsis and Septic Shock?
Sepsis- Systemic Inflammatory Response Syndrome (SIRS) plus Infection
Septic Shock- Sepsis with a systolic BP<90mmHg that is NOT Responsive to Fluids- they need URGENT Intensive Care Referral
What are the 8 signs of Skull Fracture?
Subcutaneous Haematoma
CSF Rhinorrhoea
CSF Otorrhoea
Subcutaneous Haematoma around the Eyes- Raccoon Eyes
Haemotympanum
Subcutaneous Haematoma behind the Ears- Battle Sign
Subcutaneous Emphysema
Cranial Nerve Palsies- 1-3 days after the Trauma
What 2 Interventions are contraindicated in a Skull Fracture?
Nasopharyngeal Airways
Head tilt chin lift is contraindicated in these patients
What 2 Investigations should be ordered in Head Trauma?
First line is plain CT Head
Other imaging can include CT Cervical Spine for Spinal Fractures. CT Angiogram (looking for Local Vascular Injury) and plain Skull Xray (assessing for Orbital Fractures)
What are the 8 signs of Tricyclic Antidepressant overdose?
Drowsiness
Confusion
Arrhythmia
Seizures
Vomiting
Headache
Flushing
Dilated Pupils
What 6 Investigations should be ordered if Tricyclic Antidepressant Overdose is suspected?
FBC
U&Es
CRP
LFTs
Venous Blood Gases- look for signs of Acidosis
ECG- QT Prolongation
What is the 2 step management of Tricyclic Antidepressant Overdose?
Activated Charcoal can be given within 2-4 hours of the Overdose
Patients should be reviewed by Intensive Care if there are any concerns about their airway (particularly in drowsy patients) or if they have severe metabolic acidosis that may mean they require Renal Replacement Therapy
What can trigger Trigeminal Neuralgia and what can be seen in Neurological Examination?
Triggered by light touch, eating or even wind blowing
Neurological examination in these patients is normal and pain MAY be triggered by lightly touching the patient’s face
What are the 5 causes of Trigeminal Neuralgia?
Malignancy
Arteriovenous Malformations
Multiple Sclerosis
Lyme Disease
Sarcoidosis
What is the management of Trigeminal Neuralgia? (6)
Medical Treatment-
- Carbamazepine (first line)
- Phenytoin
- Lamotrigine
- Gabapentin
Surgical Treatment-
- Microvascular Decompression
- Treatment of Underlying Cause and Alcohol Injections
What is Type 1 Respiratory Failure and what are 3 facts about it?
When there is a low PaO2 (<8kPa) with or without a LOW PaCO2
- The damaged lung tissue limits the oxygenation of the blood which results in Hypoxaemia and Hypoxia. The normal lung tissue that is unaffected is still able to maintain the excretion of carbon dioxide however
- The 2 step management for Type 1 Respiratory Failure is Prescribing Supplemental Oxygen/ CPAP and correcting the underlying cause
- If the patient is on Supplemental Oxygen, PaO2 may be normal, but inappropriately low for the Fraction of Inspired Oxygen (FiO2)
What are the 6 main causes of Type 1 Respiratory Failure?
Decreased Atmospheric Pressure
Ventilation-Perfusion Mismatch
Shunt
Pneumonia
ARDS
Pulmonary Embolism
What is Type 2 Respiratory Failure and what causes it (the pathophysiology)?
Low PaO2 and High PaCO2
Inadequate Alveolar Ventilation occurs due to failure in the Respiratory Pump and increased Ventilatory Resistance of the Entire Lungs- not Just the Lung Tissue
What are the 8 causes of Type 2 Respiratory Failure?
Chronic Obstructive Pulmonary Disorder (COPD)
Chest Wall Deformity (Kyphosis and Scoliosis)
Central Nervous System Depression due to Opioids or Sedatives
Severe Asthma
Myasthenia Gravis
Guillain-Barre Syndrome
Obesity
Respiratory Distress Syndrome
What are the 6 clinical features of Hypercapnia (seen in Type 2 Respiratory Failure)?
Headache
Altered Level of Consciousness
Warm Extremities
Behavioural Change
Asterexis
Papilloedema
What 4 investigations should be ordered in Type 2 Respiratory Failure?
Arterial Blood Gas (PaCO2>6kPa, PaO2<8kPa)
Pulse Oximetry (Measure Oxygen Saturation)
Simple Spirometry (Measure Tidal Volume and Vital Capacity)
Electrocardiogram (look for Cardiac Arrhythmias secondary to Hypoxaemia and Acidosis)
How is Type 2 Respiratory Failure managed? (4)
Treat the Underlying Pathology
Supplemental Oxygen via Nasal Canula, Face Mask, Venturi Mask or Non-rebreather Mask
Non-invasive Ventilation (CPAP or BiPAP)
Invasive Ventilation (Endotracheal Tube or a Tracheostomy)
(Also remember an Excessive Administration of Oxygen can lead to the reversal of Hypoxic Vasoconstriction. More Pulmonary Blood Flow is directed to Poorly Ventilated Alveoli, which exacerbates the Ventilation/Perfusion Mismatch as a result. Therefore the target SpO2 in patients with Severe Hypercapnic Respiratory Failure is 88-92%)
