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1. MONITORING
DR RIZWAN ANSARI
FCPS
BILAWAL MEDICAL COLLEGE LUMHS

2.  Monitoring is important to prevent anaethesia
complication
 Sophisticated monitor available, only to aid not to
fully dependent on them
 Anaesthetist vigilance is the best
INTRODUCTION

3. 1.STANDARD I
 Qualified anesthesia personnel shall be present in the room throughout the conduct
of all general anesthetics, regional anesthetics and monitored anesthesia care.
2. STANDARD II
 During all anesthetics, the patient’s oxygenation, ventilation, circulation and
temperature shall be continually evaluated.
STANDARD OF MONITORING

7. ADVANCE MONITORING
INSTRUMENTAL MONITORING

9. RESPIRATORY MONITORING
 PRECORDIAL & ESOPHAGEAL STETHOSCOPES
 PULSE OXIMETRY
 CAPNOGRAPHY
 ANESTHETIC GAS ANALYSIS

10. PRECORDIAL & ESOPHAGEAL STETHOSCOPES
 Chest auscultation remains the primary method to confirm bilateral lung
ventilation in the operating room, even though detection of an endtidal CO2
waveform is definitive to exclude esophageal intubation.
 Anesthesiologists used a precordial or esophageal stethoscope to ensure
that the lungs were being ventilated, to monitor for circuit disconnections,
and to auscultate heart tones to confirm a beating heart.

11.  The esophageal stethoscope is a soft plastic catheter (8–24FR) with
ballooncovered distal openings . Although the quality of breath and
heart sounds is much better than with a precordial stethoscope, its use
is limited to intubated patients
 The information provided by a precordial or esophageal stethoscope
includes confirmation of ventilation, quality of breath sounds (eg,
stridor, wheezing), regularity of heart rate, and quality of heart tones
(muffled tones are associated with decreased cardiac output).

12. PULSE OXIMETRY

13. Mechanism of action
The oxygen saturation is estimated by measuring the transmission of light, through a pulsatile vascular
tissue bed (e.g. finger).
This is based on Beer’s law (the relation between the light absorbed and the concentration of solute in
the solution) and Lambert’s law (relation between absorption of light and the thickness of the absorbing
layer)
The amount of light transmitted depends on many factors. The light absorbed by non-pulsatile tissues
(e.g. skin, soft tissues, bone and venous blood) is constant . The non-constant absorption is the result of
arterial blood pulsations The sensitive photodetector generates a voltage proportional to the transmitted
light.

14. components of the pulse oximeter
 It has a probe and a
microprocessor unit.
 The probe has two light-
emitting diodes (LEDs).
The light passes through
blood and other tissues
and is detected by a
photodetector.
 The microprocessor unit
displays the waveform,
oxygen saturation and
the pulse rate.

15. What is the principle of a pulse oximeter?
 Oxygenated haemoglobin absorbs more infrared light and
allows more red light to pass through. Deoxygenated
haemoglobin absorbs more red light and allows more infrared
light to pass through.
Spectrophotometry is a method to measure how much a
chemical substance absorbs light by measuring the intensity
of light as a beam of light
Spectrophotometry

16. There are the two wavelengths of the source of light
660nm (visible red spectrum) and 940nm (infra-red
spectrum)
A represents the oxyhaemoglobin absorbance spectrum. B represents the
reduced haemoglobin absorbance spectrum
A UV-visible spectrophotometer uses
light over the ultraviolet range (185 –
400 nm) and visible range (400 – 700
nm) of the electromagnetic radiation
spectrum. Whereas an IR
spectrophotometer uses light over the
infrared range (700 – 15000 nm).

17. What is the name of the point where the absorbance for the two forms of haemoglobin meet?
Analysis of the absorption of infrared at 805nm allows quantification of the
total concentration of haemoglobin present

18. What are Beer’s law and Lambert’s law?
Beer’s law
states that the absorption of radiation by a solution is proportional to the
concentration of the substance.
Lambert’s law
states that the absorption of radiation by a solution is proportional to the
thickness of the absorbing layer

19. Indications & Contraindications
 Pulse oximeters are mandatory monitors for any
anesthetic, including cases of moderate sedation.
 There are no contraindications.

20. Problems in practice and safety features
 Carbon monoxide poisoning (including smoking), coloured nail
varnish, intravenous injections of certain dyes (e.g. methylene blue,
indocyanine green) and drugs responsible for the production of
methaemoglobinaemia are all sources of error (
It is accurate (±2%) in the 70–100% range. Below the saturation
of 70%, readings are extrapolated.

22. CAPNOGRAPH

23. MEASUREMENT OF CARBON DIOXIDE
A capnograph uses the principle of infrared absorption by CO2. Gases with
molecules containing two or more different atoms absorb radiation in the infrared
region of the spectrum. CO2 has a strong absorption band at a wavelength of
4260nm.
Capnograph is the device that records and shows the graphical display of
waveform of CO2
 It displays the value of CO2 at the end of expiration, which is known as end-
tidal CO2.
In healthy adults with normal lungs, end-tidal CO2 is 32-42mmhg

24. Diagram of an end-tidal carbon dioxide
waveform.
I=inspiration; E=expiration;
A–B represents the emptying of the upper dead space of the
airways. As this has not undergone gas exchange, the CO2
concentration is zero.
B–C represents the gas mixture from the upper airways and
the CO2-rich alveolar gas.
The CO2 concentration rises continuously.
C–D represents the alveolar gas and is described as the
‘alveolar plateau’.
The curve rises very slowly.
D is the end-tidal CO2 partial pressure where the highest
possible concentration of exhaled CO2 is achieved at the end
of expiration. It represents the final portion of gas which was
involved in the gas exchange in the alveoli. Under certain
conditions
D–A represents inspiration where the fresh gas contains no
CO2.

28. Lead II is ideal for detecting arrhythmias. CM5 configuration is
able to detect more than 80% of ST-segment changes due to left
ventricular ischaemia.
Usually during anaesthesia, three skin electrodes are used
(right arm, left arm and indifferent leads). The three limb
leads used include two that are ‘active’ and one that is
‘inactive’ (earth).
In CM5, the right arm electrode is positioned on the
manubrium (chest lead from manubrium), the left arm
electrode is on V5 position (fifth interspace in the left
anterior axillary line) and the indifferent lead is on the
left shoulder or any convenient position
ECG

31. Oscillatory devices produce a digital readout and work on the principle that blood flowing through an
artery between systolic and diastolic pressures causes vibrations in the arterial wall which can be detected
and transduced into electrical signals.
The term ‘device for indirect non-invasive automated mean arterial pressure’ (DINAMAP) is used for
such devices.

33. CENTRAL VENOUS CATHETERIZATION

34. INDICATIONS
Monitoring central venous pressure (CVP),
Administration of fluid to treat hypovolemia and shock,
Infusion of caustic drugs and total parenteral nutrition,
Aspiration of air emboli,
Insertion of transcutaneous pacing leads,
 Gaining venous access in patients with poor peripheral veins.

35. CONTRAINDICATIONS
Tumors
clots, or tricuspid valve vegetations that could be dislodged or
embolized during cannulation.
 Other contraindications relate to the cannulation site.
For example, subclavian vein cannulation is relatively contraindicated
in patients who are receiving anticoagulants

36. Techniques & Complications

37. TECHNIQUE OF CVP CATHETERIZATION (THROUGH INTERNAL
JUGULAR VEIN) Seldinger technique
Patient lies in Trendelenburg position – to decrease chance air embolism .
1. The cannula with stylet is inserted at the tip of triangle formed by two heads of
sternomastoid and clavicle. The direction of needle should be slightly lateral and
towards the ipsilateral nipple.
2. Once the internal jugular vein is punctured. Stylet is removed and a J wire is
passed through cannula
3. Now the CVP catheter is railroad over the J wire 5.
4. The tip of catheter should be at the junction of superior vena cava with right
atrium – 15 cm from entry point

52. NERVE STIMULATOR

53. Used to ensure adequate reversal, and to monitor
the depth and the type of the block.