This document discusses parameters that are routinely monitored during surgical procedures, including electrocardiography (ECG), blood oxygen saturation levels (SpO2), blood pressure, end-tidal carbon dioxide (EtCO2), and temperature. Key parameters like ECG, SpO2, and blood pressure must be monitored throughout surgery. Precise measurement requires properly attaching sensors and being aware of potential errors from issues like loose or misplaced sensors. Monitoring continues in recovery to track patient status after the procedure.

1. By: Azhar Manzoor

2. Introduction
 Monitoring of patients during surgical procedure.

3.  A patient undergoing surgery under anesthesia is
usually experiencing a number of disturbances
with regard to the normal functioning of several
body systems. This means that the patient’s
physiological status needs to be monitored at all
times
 Various sensors and electrodes are attached to the
patient to gather information. These
measurements are displayed on monitors.

4. Routinely measured parameters
The parameters measured in most surgical procedures
include:
 The heart’s electrical activity via an electrocardiogram
 The respiratory rate
 The blood pressure, which can be measured by both
invasive and non-invasive means
 The body temperature via thermometers, especially
when general anesthesia lasts over 30 minutes in
duration.
 The cardiac output

5.  The arterial blood oxygen level measured by a
pulse oximeter, a photoelectric sensor clipped over
the finger or toe.
 Pulmonary functions such as end-tidal carbon
dioxide (ETCO2).
 Intracranial pressure monitor in patients suffering
from trauma to the head, or brain tumors, edema,
or intracranial hemorrhage. The sensor is inserted
through a burr hole made in the skull.

6. History
 The mostprimitivemethodofmonitoringthe patient25 years
agowas continuouspalpation of the radial pulsations through
outthe operation.

7. Purpose
 To maintainthenormalpatientphysiology &
homeostasis throughoutanesthesia andsurgery.
 Surgery is a very stressful conditiontachycardia,
arrhythmias.
 Mostdrugsused for eneral &regionalanesthesia
cause cardiogenicshock, myocardialdepression,
hypotension & arrhythmias.
 Blood loss →anemia, hypotension. So itis necessary
to recognizewhenthepatientis inneed of blood
transfusion.

8. The FOUR basic monitors.
We are not authorizedto starta surgeryinthe absence ofany
ofthesemonitors:
 ECG.
 SpO2: arterial O2 saturation.
 Blood Pressure: NIBP (non-invasive), IBP (invasive).
 ± [Capnography].
The mostcritical 2 timesduringanesthesiaare:
INDUCTION - RECOVERY.
Exactly like “flying aplane ” induction(= take off) &recovery
(= landing). The aimis to achieve a smooth induction&a
smooth recovery &a smooth intraoperative course.

9. (1) ECG
 Graphical representation of electrical activity of heart.
 The machine which is used to record the electrical
activity of heart is ELECTROCARDIOGRAPH.
 The graph on which the electrical activity is recorded
is called ELECTROCARDIOGRAM.

10. Significance of ECG
 ECG gives information about rate and rhythm of
the heart.
 It is a diagnostic tool for various heart conditions like
hypertrophies , ischemia, infarction , arrhythmias and
pace maker activity.
 Timing ofECG monitoring:Throughout the surgery:
before induction until recovery

11. ECG Paper
• This is long role of paper ,composed of small
squares.
• One square is 1mmwideand 1 mm high.
• On ECG paper there are thick lines, between two thick
lines there are 5 small squares.
• The speed of ECG machine is 25 mm per second.

12. • The time internal of each small square can be calculated
as
• 25 small sqrs are equal to 1 second.
• 1 small sqr is equal to 1/25 second.
• i.e 0.04 seconds.

13. 

14. • vertically the small square represent the amount of
electrical potential.
• One small sqr represent the potential of 0.1 mv.
• 10 small squares represent the potential of 1 mv.

15. ECG Leads
 There are 10 electrodes in 12 lead ECG placed on
patients limbs and on the surface of chest.

16. How to attach ECG electrodes:
 Prepare the skin
 Before placing your electrodes, it is very important to
prepare the subject's skin by wiping the chest area
thoroughly with skin cleansing (alcohol) swabs. This
removes any oil that may be on the skin and which can
cause drift in your ECG/EKG signals.
 Once the skin is clean, find and mark the placements for
the electrodes...

17.  Find and mark the placements for the electrodes:

18.  Apply limb leads

19. Wave Forms
 P wave
Atrial depolarization
 QRS complex
Ventricular depolarization
 T wave
Ventricular repolarization

20. P Wave
• P Waveshows atrial
depolarization..
• Its duration is 0.1 sec (2 and half
small
sqr)
and height is 2.5 mv (2 and half
small sqr).
• Presence of p waves in ECG
strip shows the sinus rhythm.

21. QRS Complex
 QRS complex represent the ventricular
depolarization.
 its normal duration is about 0. 08 seconds
(less than 2 small sqr) and hight is about 5
to 20 small sqrs.
 Q wave is first wave of this complex but
often absent.

22.  Q wave present the interventricular
depolarization.
 It is first wave in ECG with negative deflection.
 Q wave greater than 1/3 the height of the R wave,
greater than 0.04 sec are abnormal and may represent
the old infarction.

23. T Wave
• it represent the ventricular repolarization.
• It is repolarizing wave but shows the upward
deflection.

24. • T wave should not be more than one third of R wave.
• T wave inversion represent ischemia of heart.
• Tall and peaked R wave is present in hyperkalemia.

25. (2) SpO2
 SpO2, also known as blood oxygen saturation, is a measure
of the amount of oxygen-carrying hemoglobin in the blood.
The body needs there to be a certain level of oxygen in the
blood or it will not function as efficiently. In fact, very low
levels of SpO2 can result in very serious symptoms. This
condition is known as hypoxemia. There is a visible effect on
the skin, known as cyanosis due to the blue (cyan) tint it takes
on. Hypoxemia (low levels of oxygen in the blood) can turn
into hypoxia (low levels of oxygen in the tissue).

26.  Timing ofSpO2 monitoring:
 Throughoutthe surgery: It is the LAST monitortobe removed offthe
ptbeforetheptis transferredoutside the operatingroomtorecovery
room.SpO2 monitoringshouldbe continuedinrecovery room.

27. Measuring SpO2
• There are many ways that the blood can be tested to ensure it
contains normal oxygen levels. The most common way is to
use a pulse oximeter to measure the SpO2 levels in the blood.
Pulse oximeters are relatively easy to use, and are common in
health care facilities and at home.To use a pulse oximeter,
simply place it on your finger. Can also be applied to the
ear lobe.
• A percentage will be displayed on the screen. This percentage
should be between 94 percent and 100 percent, which
indicates a healthy level of hemoglobin carrying oxygen
through the blood. If it is less than 90 percent, you should see
a doctor.

28. 

29. Cyanosis of the tissue in the
hand

30.  Fallacies &Inaccuracies occur when:
 Misplaced onthepts finger, slipped.
 Pt movement, shivering.
 Tissue perfusion (cold extremities) →warmthept, put
a glove filled withwarmwater in thepts hand (always
avoid hypothermia).
 Cardiac arrest.

31. Rules
 Keep thesound ofthepulse oximeterON at all times.
 ALWAYS Remember thatyourclinical judgement is muchmore
superiortothe monitor.Check ptcolourforcyanosis: lips, nails.
 Ifhypoxemiaoccurs immediately check theptscolour : nails &lips,
thenmanageaccordinglyandcallforhelp.

32. (3) Blood Pressure
 Timing of BP monitoring :throughout the
surgery.
 Frequency of measurement:
 By default every 5 minutes.
 Every 3 minutes: immediately after spinal
anesthesia.
 Every 10 minutes: eg. Inawake pts under local
anesthesia.

33. Reading errors/Failures
 Pressure line is disconnected.
 Leakage from damaged cuff.
 Line is compressed (under someone’s foot or under a
weal).
 Line contains water from washing!

34. How to Attach
 Correct cuff size : width of the cuff should be 1.5
times limb diameter and should occupy at least 2/3 of the
arm.
 2 cuff sizes for adult: blue : for most adult individuals
(60-90 Kg), red : for morbid obese.
 Selection of appropriate cuff size is importantbecause a
tight cuff leads to false high readings, while a L oose cuff
gives false Low readings.

35. IBP:
 Itis beat tobeat monitoringofABP via an arterial
cannula.
 Indicated in: major surgeries, cardiac surgery, in surgeries
involving extreme hemodynamic changes/instability eg.
Pheochromocytoma.

36. (4) Capnography
 Definition
Continuous CO2 measurement displayed as a
waveform sampled fromthe patient’s airway during
ventilation.
Normal range: 35-40mmHg
 What is EtCO2?
 A point onthecapnogram. Itis thefinal measurement
at theendpointofthepts expiration before inspiration
begins again. Itis usually thehighest CO2
measurement during ventilation.

37. Terminology
 Capnography:- A real time waveform recorded of the
concentration of carbon dioxide in the respiratory
gases.
 Capnogram:- it is waveform + numeric value.

38. 

39.  Phases of the capnogram:
 A-B End of inspiration
 B-C Beginning of expiration
 C-D Alveolar plateau
 D-E Beginimg of new breath
 E-A End of inspiration

40. Factors that affect CO2 levels
Increase in ETCO2 Decrease in ETCO2
Increased muscular activity Decreased muscular activity
Increased cardiac output Decreased cardiac output
hypoventilation Hyperventilation
Partial airway obstruction Pulmonary embolism

41. Individual system monitering
 Respiratory System.
 CNS: Awareness.
 Temperature.
 Monitoringafter Extubation & Recovery.

42. Respiratory monitoring
 Clinical monitoring:
 Colour: cyanosis : nails, lips, palms, conjunctiva.
 Chest rise &fall (inflation).
 Ventilator sound : duringrespiratory cycle. Abnormal sounds
eg. leakage, disconnection, highairway pressure.

43. CNS Awareness
 Clinical monitoring: Signs ofptawareness:
 Movement, grimacing (facial expression)
 Pupils dilated.
 Lacrimation.
 Tachycardia.
 HTN.
 Sweating : is always an alarming/warningsign.
 Causes
 Hypoglycemia.
 Hypercapnia.
 Thyroid storm (thyrotoxic crisis).
 Fever.

44. Temperature monitoring
 Clinical monitoring : urhands.
 Monitors : temperature probe:
esophageal, nasopharyngeal.

46.  Nasopharyngeal

47. Complications of hypothermia
 Cardiac arrhythmias: VT & cardiac arrest.
 Myocardial depression.
 Delayed recovery (delays drug metabolism).
 Coagulopathy.

48. How to avoid hypothermia:
 Warm IV fluids.
 Intermittently switching off air- conditioning esp.
towards the end ofsurgery ( ↑ ambient roomtemp).
 Pediatrics: warming blanket.

49. Monitoring after extubation and
recovery
 After extubation : immediately fit the face mask on theptand
observe thebreathing bag
 Good regular breathing with adequate tidal volume transmitted
tothebag.
 No transmission tothe bag →respiratory obstruction
 SpO2: ˃ 92%
 Breathing : regular.
 Level of consciousness : fully conscious.
 1) obeying orders,
 2) eye opening,
 3) purposeful movement.
 Most IMP: Pt must be able to protect his ownairway.

50. To summarize
 The 4 basic monitors displayed on the screen:
1 ) ECG.
2) BP.
3) SpO2.
4) ± Capnogram (EtCO2).