Adams regulatorPressure reducing valve to anaesthetic machine (12 psi).
Adjustable Pressure Limiting ValveExpiratory
relief valve, to protect patient's lungs against high breathing gas pressures
during spontaneous breathing.
AnaesthesiaLoss of sensation, to relieve the patient from
awareness, pain, or muscle control.
| Epidural||Injection of a local
analgesic into the epidural space, blocking the spinal nerves.
| General||Unconsciousness induced by inhalational, IV, or a
combination of both techniques.|
| Local||Localised application of topical or injected analgesic.|
| Regional||Typically, an analgesic blocks
sensation to a complete limb.|
| Spinal||Injection of local anaesthetic into
the cerebrospinal fluid of subarachnoid space around the lower spinal nerves.|
| TIVA||Total Intravenous Anaesthesia|
British Journal of Medicine
Anaesthetic machinesSee Airway
Drug (eg, Neostigmine, Distigmine, Pyridostigmine) which inhibits acetylcholinesterase,
preventing it from metabolising acetylcholine. Result is increased levels of
acetylcholine, with consequent reduction of muscular block from agent, such as
Atracurium. Also prolongs action of Suxamethonium. Has muscarinic side-effects,
which are antagonised by Atropine.
AnticoagulationUsing a drug to reduce the chance of a blood clot
forming, such as when helping to prevent a stroke from occurring. Commonly used
anticoagulant drugs are Heparin and Warfarin.
Drug to relieve nausea/vomiting, often caused by
emetogenic agents, such as opioid analgesics and nitrous oxide.
Anticholinergic Drugs, such as Atropine and Glycopyrronium, reduce
muscarinic effects of Neostigmine, and prevent bradycardia and hypotension
associated with Halothane, Propofol, and Suxamethonium. Also, drugs which reduce
intestinal motility eg, in management of irritable bowel syndrome.
AntispasmodicRelieves/prevents muscle spasms.
ASA ratingAmerican Society of Anaesthesiologists rating
scheme for the physical state of a patient.
|I||Normally healthy individual
|II||A patient with mild systemic disease|
|III||A patient with severe systemic disease which is not
|IV||A patient with incapacitating systemic disease which is a
constant threat to life|
|V||A moribund patient who is not expected to survive 24 hours
with, or without, an operation|
|E||Added as a suffix for emergency cases|
AuscultationListening to internal organs.
BarbituratesGroup of sedative and hyponotic drugs, such as
Thiopentone and Methohexitone.
BarotraumaInjury due to excess pressure in tissues.
BenzodiazapinesDrugs used for sedation, anxiety relief, muscle
relaxation, anti-convulsive. For example: Midazolam, Oxazepam, Diazepam,
Lorazepam. Reversed by Flumazenil.
Beta (β) blockers
Beta-adrenoceptor blockers: Negative inotropic drugs which block the
affect of Adrenaline on the heart and blood vessels, by weakening effects of the
Sympathetic Nervous System on heart conductivity, and reducing blood pressure
and heart rate. Description
Bier blockIntravenous regional anesthesia where an
extremity, such as a leg, is made numb for surgery, by injecting a local
anaesthetic into a vein, after the blood has been squeezed out of the extremity,
and a tourniquet has been placed distal to the surgical site. Typical anaesthetics
used are 0.5% Prilocaine or 0.5% Lignocaine. A typical adult dose for a leg is
50-60 ml, and 40 ml for an arm.
The tourniquet prevents the local anaesthetic from leaving the extremity,
and blood from entering it, giving the patient a numb extremity, and the surgeon
a bloodless field in which to work. The tourniquet should be inflated to a pressure
at least 50 mm/Hg above the patient's systolic blood pressure. There is a time limit
of 1-2 hours on the application of a tourniquet, due to the oxygen starvation which
occurs in the region which has an impeded venous flow. If the tourniquet is released
whilst a large amount of the anaesthetic is yet to be metabolized, blood toxicity
Transfusion of blood is governed by the Blood Safety and Quality Regulations (2005),
which describe all stages of transfusion,
from donation to patient adminstration. Problems with transfusion must be reported
according to the SABRE
protocol. Blood description and testing
Broviac lineA centrally inserted venous catheter to
provide intravenous administration - similar to a Hickman line.
G.A. setup ||
CannulaA hollow needle, inserted into a central or
peripheral vein, to facilitate intravenous fluid administration.
Cardiac drugsFor cardiothoracic procedures, drug and
venous access preparation is different from other types of surgery.
Cardioversion The conversion of an
arrhythmia, such as Atrial fibrillation,
to a sinus (normal) rhythm, using an electrical defibrillator or by pharmacological
means. Energy levels
Also known as autologous blood salvage; a medical procedure involving the recovery of
blood lost during surgery, and re-infusing it into the patient.
CEPODConfidential Enquiry into Perioperative Deaths:
|1||Elective||Operation at time to suit Surgeon,Anaesthetist, and patient.|
|2||Scheduled||Operation within 24 hours. Delayed operation after resuscitation.|
|3||Urgent||Operation between 1 and 3 hours. Early surgery preferred, but not life saving.|
|4||Emergency||Operation within 1 hour. Immediate operation or resuscitation simultaneous
with surgical treatment.|
ColloidsIntravenous fluids which help to support blood volume,
and will not cross semi-permeable membranes (unlike crystalloids), such as
capillaries, but will remain within the cardiovascular system.
Note: Colloids are not as good as crystalloids for correcting electrolyte
- Dextrans 40
- Dextrans 70
- Hydroxyethyl Starch
ComaUnconsciousness, where the patient cannot be aroused, has no
normal eye movements, and does not respond to stimuli, such as pain.
Combined Spinal/EpiduralOffers the fast onset time of a Spinal
(sub-arachnoid block) anaesthetic, with the advantage of topping up offered by
an Epidural anaesthetic. See
CrystalloidsIntravenous fluids which cross semi-permeable membranes,
thereby useful for correcting electrolyte imbalances.
Depolarising neuromuscular blockPersistent depolarization of
skeletal muscles, making the muscle fiber resistant to further stimulation by
DiureticAn agent, such as Furosemide, which increases urine
Drop factorDrops per ml (millilitre) of fluid administration sets.
Common drop factors...
- 10 drops/ml (blood)
- 15 drops/ml (blood)
- 20 drops/ml (crystalloid)
- 60 drops/ml (microdrop)
DrugsGeneral anaesthetic drugs.
Drum Cartridge CatheterA method used in central vein cannulation. The vein
is cannulated with an introducer cannula. The needle is removed, and is replaced by the
drum cartridge catheter, which is left in place.
Epidural: outside the Dura Mater. In anaesthesia, the injection of a local analgesic into
the epidural space, to block the nerve routes from the spinal cord. Used in procedures involving
the lower limbs, pelvis, perineum and lower abdomen. Also commonly used to alleviate pain in
childbirth, usually started during labour, and given before the neck of the womb has started
Pre-operative fasting for elective surgery:
Adults: 2 hours for water;
6 hours for solids and milky drinks.
Children: 2 hours for water;
4 hours for breast milk; 6 hours for solids and other types of milk.
Fetching the patientPolicy for "fetching" elective patients.
Gas cylindersHigh pressure gas cylinders are colour coded, for safety.
The following colour coding will, eventually, be superceded by a new EU scheme:
||Cylinder colour||Shoulder colour||Pin index|
|Air||Grey||Black & white||1,5|
|Entonox||Blue||Blue & white||Central|
Gas suppliesTypical supplies to a theatre are: Air, Oxygen, and
Nitrous Oxide, at a pressure of 400-500 kPa.
Hartmann's solutionColloid balanced salt solution, used mainly for
general extracellular fluid replacement. Contains calcium, chloride, lactate, sodium.
Health and Safety at Work Act Imposes duties on employers and
employees to protect all persons from harm, whilst at work, and mandates requirements
for Welfare at work. The Act
Hickman lineA central line which allows intravenous administration, and
blood sampling. The line is inserted through a vein (neck or chest), and tunnelled under
the skin, to it's exit point at the shoulder or chest. There will be 1-3 lumens.
Derby Hospital ||
ICU bedBefore leaving theatre, patients destined for Intensive Care
Units must be transported on special beds, which must be checked for the following:
Suction equipment, Ventilator, Oxygen cylinder, Monitoring equipment,
Mapleson C, Capnometer, Ambu bag.
Infusion pumpA machine which infuses fluids and medications at a
pre-determined rate. Can be used for IV, epidural, arterial, or subcutaneous infusions.
InotropeA substance which increases the force of muscular contractions,
particulary of the heart muscle. Examples: Adrenaline, Ephedrine.
Intravenous dripEquipment which delivers intravenous
fluids/drugs at a rate set by manipulation of a thumb wheel.
Local anaesthetic toxicitySee
Minimum Alveolar Concentration (MAC)MAC is the concentration
(partial pressure) of an anaesthetic vapour, in the alveolus, at 1 atm pressure (relative),
given with oxygen, which does not produce a response in 50% of subjects, when exposed to a
surgical stimulus. The MAC value is exclusive of other agents being used for the anaesthetic
- Propofol etc.
Plotting the proportion of patients not moving, as
a consequence of the anaesthetic concentration, creates
a dose-response curve (Normal Distribution). MAC is a
single point on this curve, corresponding to the 50% (median) point, where patients do not move
in response to the stimulus. The standard deviation (sd) of an agents MAC is approximately 10% of
that MAC; for example, 1.2 MAC (MAC + 2 sd) should not produce a response to stimulation in
~97.7% of patients, which is all but the right-most 2.3% of the normal distribution curve.
Similarly, 1.3 MAC (MAC + 3 sd) should not elicit a response in ~99.8% of patients.
For example, for a 40 year old patient, the MAC value for Sevoflurane is
2.1, which means that the above 50% level is reached when the partial pressure of Sevoflurane,
in the alveolus, is 2.1% of an atm (2.1 kPa || 21.7 cm/H2O || 21.3 mBar).
Moffett's solutionA topical anaesthesia solution, which reduces
bleeding in ENT procedures.
|Agent ||Soution ||Volume |
|Adrenaline ||1:1000 ||1 ml |
|Cocaine ||10% ||2 ml |
|Na Bic. ||8.4% ||4 ml |
|Saline ||0.9% ||13 ml |
NaloxoneAn opioid antagonist, which counters depression
of the central nervous system, caused by opioids.
Nasogastric tubeA tube which is passed through the nose to the stomach,
allowing stomach contents to be drained into a bag. A nasogastric tube weakens the
effect of the gastrooesophageal sphincter, and makes regurgitation of stomach contents
more likely, shown by increased intragastric pressure. The increase in pressure is the
basis of vomiting, and may be decreased if the intragastric pressure can be reduced.
Do this by allowing the tube to drain freely, so fluid moves up the tube to the bag.
Nerve blockInjection of a local anaesthetic agent
close to a peripheral nerve or nerve plexus.
Nerve stimulatorsAdminister electrical stimuli to peripheral nerves eg,
wrist ulnar. Strength in Coulombs (product of amps and seconds). Typical current is
6 mA, over 0.2
mS, with resultant charge of 1.2
µC. Stimulus longer than 0.3 mS can produce
repetitive nerve or muscle stimulation. Less charge to deliver supramaximal
stimulus necessary when negative electrode placed distally.
Non-depolarising blockNon-depolarising muscle relaxant drugs
compete with acetylcholine (ACh) molecules, released at the neuromuscular junction, to
bind with nicotinic receptors on the post synaptic membrane of the motor endplate.
These drugs block the action of ACh, which prevents depolarisation/contraction of the
muscle. These blocking agents relax the diaphragm, abdomen, and vocal chords. The
patient, therefore, will require assisted ventilation during anaesthesia.
groups differ in their sensitivity to muscle relaxants; the ocular muscles, which are
responsible for moving the eyes, are the most sensitive, followed by the muscles of the
jaw, neck, limbs, intercostals, and abdomen. The diaphragm is the least sensitive muscle,
which is why patients undergoing surgery sometimes hiccup or breathe, as an early sign
that the relaxants are wearing off. The reversal agent for the block is Neostigmine - an
Non Steroidal Anti-inflammatory drugsSee Science
Oxylog Ventilator 3000Manual
Patient controlled anaesthesiaIntravenous infusion of analgesia, controlled
by the patient, using a syringe driver, such as the Graseby pump.
Patient transfer to operating table
The priorities are...
- Manage the airway
- Monitor oxygen saturation
- Prevent nerve and pressure point damage
Peripherally Inserted Central Catheter (PICC)A peripherally inserted
central catheter is an alternative to a centrally inserted line, and can be used for
prolonged periods, to provide IV access and total parenteral nutrition.
The PICC is
inserted into one of the large peripheral veins (near the elbow), such as the cephalic,
basilic, or brachial veins, and then advanced through increasingly larger veins, towards
the heart, until the tip rests in the distal superior vena cava or cavoatrial junction.
Precordial thumpAn attempt to interrupt an arrhythmia, such as Ventricular
Fibrillation or pulseless Ventricular Tachycardia, by making a single strike, with the
fist, to the centre of the patient's sternum. The thump is only effective if made at the
onset of a witnessed and monitored adverse rhythm (VF/pVT), and a defibrillator is not
immediately available. Latest resuscitation guidelines de-emphasise use of the precordial thump.
Primary surveySteps to take when assessing an unconscious
Order of steps
|Danger||Assess Dangers to yourself and casualties|
|Response||Use the Glasgow Coma Scale to ascertain the level of
|Airway||Examine the Airway for obstructions|
|Breathing||Look, listen, and feel for adequate respiratory effort.
Supplement with oxygen to correct hypoxia, if saturations are below 95%|
|Circulation||If a carotid pulse is not palpable, then
resuscitation should be commenced|
Rapid Fluid Infusion
The rapid intravenous introduction of fluids, such as saline or blood products, into
the haemodynamically unstable patient, with the aim of correcting hypovolaemia and
Rapid Sequence Induction
Anaesthesia affecting only a part of the body, typically a limb. Generally involves the
introduction of local anaesthetic to block the nerve supply to a part of the body, such
as a leg. Unlike general anaesthesia, patients may remain awake during their procedure,
resulting in reduced side-effects, and enabling the surgeon to converse with the
patient during the procedure.
Regional block types...
- Central eg, epidural and spinal (neuroaxial)
- Peripheral plexus eg, brachial plexus
- Peripheral single nerve
The anaesthetic agent may be given in two ways:
- Injection directly into a vein, which has it's venous flow impeded by a
- Intravenous continuous flow (Bier block), via
a catheter, eg, continuous peripheral nerve block.
Ring block (field block)Local anaesthetic infiltration circling the
surgical site, without injection into the site itself. The block prevents nerve
impulses from leaving the site when, for example, it is undesirable to 'pullute' the
site with the anaesthetic agent.
Secondary surveyA more in
depth survey of the patient than the primary survey.
SedativeAn agent which relieves tension and anxiety. Commonly
used sedatives are the Benzodiazepine anxiolytic agents:
These agents are antagonised by Flumazenil.
Seldinger techniqueA method of introducing catheters and probes
- Puncture the vessel with a needle.
- Insert the Seldinger wire through the needle into the vessel.
- Remove the needle.
- Use the Seldinger wire as means of access to the vessel.
Spinal (subarachnoid) blockAn injection of anaesthetic
agent, typically Diamorphine or 0.5% Heavy
Marcaine, into the intrathecal space and the cerebrospinal fluid of the
subarachnoid space, around the lower spinal nerves, below L2, so as to avoid
piercing the spinal cord. Details
Subcutaneous cannulaA cannula placed between skin and muscle.
- Insert cannula at a 45° angle
- Ensure pectoral fin is flat against skin
- Press in wings to squeeze out needle
- Replace cap
- Aspirate at white cap with 10ml syringe - ensure no blood
- Refit white cap
- Apply clear Tegaderm dressing
Subcutaneous injectionAn injection into the fatty layer
between the skin and muscle. Subcut injections are given because there is little
blood flow to fatty tissue, and the injected medication is absorbed more slowly.
Some medications, which can be injected subcutaneously, include growth hormone,
insulin, and adrenaline. Procedure
Suxamethonium apnoeaProlonged effect of Suxamethonium,
which means a patient may reverse from anaesthesia, but remain paralysed.
SympathomimeticsDrugs which mimic the effects of the
sympathetic nervous system, and used in the treatment of cardiac arrest and
SyncopeTemporary loss of consciousness.
A portable, battery operated device for mechanical subcutaneous delivery of a drug,
at a predetermined rate, and over a specific period. It's purpose is to achieve a steady
plasma concentration of the drug. Two commonly used syringe drivers are the Sims Graseby
MS26 and MS16A.
|MS26||Green||Delivery rate at mm per 24 hours|
|MS16A||Blue||Delivery at mm per hour|
TachycardiaFast heart rate/pulse.
Transversus Abdominis Plane block
Total intravenous anaesthesia (TIVA)
General anaesthesia using a combination of intravenous agents, but no inhalational
gases. A target controlled infusion device controls the dosages, typically consisting
Propofol and Remifentanil. Equipment
Transversus Abdominis Plane blockA
local anaesthetic block, to the anterior and lateral abdominal wall, to provide
Tuohy needle A hollow hypodermic needle, very
slightly curved at the end, suitable for inserting epidural catheters.
Ultrasound guided continuous peripheral nerve block
A substance which causes contraction of blood vessels, resulting in reduced blood
flow and increased blood pressure. Acts directly, or indirectly, on the
SNS. Often used in resuscitation,
and to treat hypotension in surgical patients.
Perioperatively, Ephedrine and Metaraminol should always be immediately available.
Ephedrine has a faster onset than Metaraminol, but only lasts for about 10 minutes;
whereas Metaraminol lasts 20-60 minutes.
Ephedrine is safe for use in pregnancy, as it does not reduce placental blood flow.
Volatile anaesthetic agentsAnaesthetic
agents which are liquid at room temperature, but evaporate easily for administration