Patient monitoring involves both non-instrumental and instrumental assessment. Non-instrumental monitoring includes visual observation of factors like respiratory pattern, bleeding, and IV lines. Instrumental monitoring provides quantitative data through devices like ECG, blood pressure cuffs, pulse oximetry, capnography, and muscle relaxation monitors. Together, non-instrumental and instrumental monitoring provide clinicians with vital information about patients' physiological status to guide care in settings like operating rooms and intensive care.

1. Patient Monitoring
Patient monitoring and the equipment to
support it are vital to caring for patients
in operating rooms, intensive care units,
emergency departments, and in acute care
settings

2. :Patient Monitoring divided into
• Non Instrumental: clinical observation
(“look, listen, feel”)
Visual and auditory surveillance is central to
patient monitoring, and involves many
dimensions:
• Observing the patient’s color, respiratory
pattern, accessory muscle use, and
looking for movements, grimaces or
unsafe patient positioning

3. • Observing the patient’s clinical data on
intraoperative monitors
• Observing bleeding and coagulation at the
surgical site (e.g., are the surgeons using many
sponges or are they doing a lot of suctioning?)
• Monitoring the functioning of all lines to ensure
that IV catheters have not infiltrated
• Conducting an anesthesia machine and
workspace checkout

4. • Pulse: rate, volume, rhythm------etc
• Capillary refilling
• Sweating

5. Instrumental patient monitoring
• Electrocardiogram (Provides information about
rate, rhythm, ischemia (ST Segments))
• Blood pressure (manual, automatic, arterial
catheter)
• Pulse oximeter (usually on fingertip or ear lobe)
• Capnograph (especially in patients with an
LMA or ETT)
• Oxygen analyzer (part of anesthesia machine)
• Anesthetic agent concentration analyzer

6. 7. Temperature (usually esophageal or axillary)
8. Precordial or esophageal stethoscope (Listen to
heart sounds, breath sounds)
9. Gas flows/ spirometry (part of anesthesia
machine)
10. Airway pressure monitor (part of anesthesia
machine)
11. Airway disconnect alarm (part of anesthesia
machine)
12. Peripheral nerve stimulator (where
appropriate)
13. Urometer (measure urine output where
appropriate)

7. Electrocardiogram ECG
This provides the clinician with three types of
information: (1) heart rate, (2) cardiac rhythm
(3) information about possible myocardial
ischemia (via ST segment analysis) In addition,
ECG monitoring can help assess the function of
a cardiac pacemaker
The most common electrocardiographic system
used during anesthesia is a 5-electrode lead
system. This arrangement allows for the
recording of any of the six limb leads plus a
single precordial (V) lead

9. Blood Pressure
Measurement of arterial blood pressure is an
important indicator of the adequacy of circulation
Systemic blood pressure monitoring is
commonly performed indirectly using extremity-
encircling cuffs or directly by inserting a catheter
into an artery and transducing the arterial
pressure trace.
Variety of techniques available for measuring
changes in systolic, diastolic, and mean arterial
pressure (MAP).

10. Indirect Measurement of Arterial
Blood Pressure
The simplest method of blood pressure
determination estimates systolic blood
pressure by palpating the return of the
arterial pulse while an occluding cuff is
deflated. Modifications of this technique
include the observance of the return of
Doppler sounds, the transduced arterial
pressure trace, or a
photoplethysmographic pulse wave as
produced by a pulse oximeter.

11. • Auscultation of the Korotkoff sounds
permit estimation of both systolic (SP) and
diastolic (DP)
• blood pressures. MAP can be calculated
using an estimating equation (MAP = DP +
1/3 [SP-DP]).

12. • The American Heart Association recommends
that the bladder width for indirect blood pressure
monitoring should approximate 40% of the
circumference of the extremity.
• Bladder length should be sufficient to encircle at
least 60% of the extremity.
• Falsely high estimates result when cuffs are too
small, when cuffs are applied too loosely, or
when the extremity is below heart level.
• Falsely low estimates result when cuffs are too
large, when the extremity is above heart level, or
after quick deflations.

13. Automated Intermittent
Technique
Many limitations of manual intermittent blood
pressure measurement have been overcome by
automated NIBP devices, which are now used
widely. In addition, automated NIBP devices
provide audible alarms and can transfer data to
a computerized information system. However,
the greatest advantage of automated NIBP
devices over manual methods of blood pressure
measurement is that they provide frequent,
regular blood pressure measurements and free
the operator to perform other vital clinical duties.

14. • In a generic noninvasive oscillometric
monitor (noninvasive blood pressure, or
NIBP),
• Cuff pressure is sensed by a pressure
transducer whose output is digitized for
processing.
• After the cuff is inflated by an air pump,
cuff pressure is held constant while
oscillations are sampled.

17. Direct method (intra-arterial pressure
(monitoring
Intra-arterial pressure monitoring provides
an invasive, continuous measure of blood
pressure by beat-to-beat reproduction of
the arterial pressure waveform

18. The method requires the insertion of a short
parallel-sided cannula into an artery.
A continuous flow of either saline or
heparinised saline at rates between 1 and
4 ml per hour is used to reduce clot
formation in the cannula.
The cannula is connected by a short length
of narrow-bore, noncompliant
plastic tubing containing saline to a pressure
transducer

19. Indications for Arterial
Cannulation
1. Continuous, real-time blood pressure
monitoring
2. Planned pharmacologic or mechanical
cardiovascular manipulation
3. Repeated blood sampling
4. Failure of indirect arterial blood pressure
measurement
5. Supplementary diagnostic information from the
arterial waveform
6. Determination of volume responsiveness from
systolic pressure or pulse pressure variation

20. Hazards of Arterial Cannulation

21. Pulse Oximetry
Pulse oximetry is a simple noninvasive method of
monitoring arterial oxygen saturation (the percentage of
hemoglobin (Hb) with oxygen molecules bound)
The arterial saturation obtained in this manner is usually
designated as SpO2
A pulse oximeter consists of a probe attached to the
patient’s finger, toe, or ear lobe, which is in turn attached
to the main unit
It measures the red and infrared light wavelength
transmitted through and/or reflected by a given tissue
In most units, an audible tone occurs with each heart beat
which changes pitch with the saturation reading

26. A patient is generally said to be hypoxemic when
the SpO2 falls below 90%, a point usually
corresponding to an arterial PO2 of 60 mmHg
An important advantage of using a pulse oximeter
is that it can detect hypoxemia well before the
patient becomes clinically cyanotic.
Note that pulse oximetry is required in all patients
undergoing anesthesia. However, it is important
to realize that pulse oximeters give no
information about the level of arterial CO2 and
are therefore useless in assessing adequacy of
ventilation in patients at risk of developing
hypercarbic respiratory failure

27. Sources of error in oximetry
1. Ambient light – can be minimized by using shielded probes.
2. Low perfusion states – amplitude of the probe signal amplitude
depends on tissue perfusion (decreased perfusion reduces signal
amplitude).
3. Motion artefact – can be reduced by increasing the signal
averaging time, but only at the expense of response time
4. External dyes. Methylene blue has the most dramatic effect – as
concentration increases, SaO2 values decrease. Some dark nail
polishes can also interfere with oximetry.
5. Effect of additional haemoglobin species on absorbance: HbMet,
HbCO and has no effect in HbF, HbS
6. Anaemia – there is a linear trend to underestimateSaO2 as the
concentration falls; at haemoglobin levels of 8 g 100 ml−1 this can
be 10–15%. Polycythaemia has no effect. Accuracy is less at low
saturation levels in anaemic patients.
7. Diathermy – interference effect largely depends on the particular
oximeter.

28. Capnography and Ventilation Monitoring
Normal PaCO2 is 35-45 mmHg
Capnography is the continuous analysis and
recording of carbon dioxide (CO2)
concentrations in respiratory gases.
A capnograph uses one of two types of analyzers:
mainstream or side- stream.
Mainstream units insert a sampling window into
the breathing circuit for gas measurement, while
the much more common sidestream units
aspirate gas from the circuit and the analysis
occurs away from the circuit Capnographs
utilizes infrared technology (most commonly), or
other techniques such as mass spectroscopy

29. It is useful to monitor capnography for a
number of important clinical situations
1. Detecting when an anesthetic breathing circuit
disconnects
2. Verification of endotracheal intubation (a
sustained normal capnogram is not obtained
when the endotracheal tube ends up in the
esophagus)
3. Assisting in the detection of hypoventilation
(raised end-tidal CO2 is often present) and
hyperventilation (low end-tidal CO2 is often
present)

30. 1. Detecting rebreathing of CO2 (in which
case the inspiratory CO2 level is
nonzero)
2. Detecting capnograph tracings
suggestive of COPD (where no plateau is
present in the capnogram)
3. Monitoring CO2 elimination during
cardiac arrest and CPR

31. Mainstream capnograph

32. Sidestream capnograph

33. Monitoring Muscle Relaxation
• Muscle relaxation, or paralysis using neuromuscular
blocking agents such as vecuronium is often required
during surgery. For instance, muscle relaxation
• may be needed to facilitate tracheal intubation, to allow
abdominal closure, or to ensure that no movement
occurs during neurosurgery
• In such settings, neuromuscular blockade monitoring or
“twitch monitoring” is employed. This usually involves
electrode placement at the ulnar or facial nerve, with use
of a peripheral nerve stimulator

34. Types Twitch Monitoring
• TWT: Single Twitch
• TET: Tetanic Stimulation
• PTC: Post Tetanic Count
• DBS: Double Burst Stimulation
• TTOF: Train Of Four

35. The stimulation modes allow the
assessment of:
• The best time for intubation
• The block degree during the anesthesia
procedure
• The need of an additional dose of the
blocking agent
• The presence of the residual block

38. Temperature Monitoring
Normal core temperature in humans usually varies
between 36.5 and 37.5°C
Heat loss is due to impairment of thermoregulatory
control by anesthetic agents combined with
exposure to the cold operating room
environment
Hypothermia is defined as a core body
temperature of less than 35°C and may be
classified as mild (32–35°C), moderate (28–
32°C), or severe (<28°C)

39. • Core temperature can be measured with
sensors in the nasopharynx, esophagus,
pulmonary artery, tympanic membrane, or even
in the rectum or urinary bladder.
• Skin-surface temperature tends to run much
lower than core temperature, but follows core
temperature trends fairly well.
• The ASA standards for patient monitoring
require that every patient receiving anesthesia
have temperature monitoring “when clinically
significant changes in body temperature are
intended, anticipated, or suspected.”

40. Central Venous Pressure Monitoring
normal value 3-8mmHg
Central venous cannulas are important portals for
intraoperative vascular access and for the
assessment of changes in vascular volume
Central venous cannulas permit the rapid
administration of fluids, insertion of PACs, insertion
of transvenous electrodes, monitoring of central
venous pressure (CVP), and a site for
observation and treatment of venous air
embolism.

41. The right internal jugular vein is the preferred site
for cannulation because it is accessible from
the head of the operating table, has a predictable
anatomy, and has a high success rate in both
adults and children. The left-sided internal jugular
vein is also available but is less desirable
because of the potential for damaging the thoracic
duct or difficulty in maneuvering catheters
through the jugular–subclavian junction.
Accidental carotid artery puncture is a potential
problem with either location

42. Pulmonary Artery Pressure Monitoring