An Introduction To Surgical Icu

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AN INTRODUCTION TO SURGICAL ICU.

MOHAMED EMAD ABDEL-GHAFFAR.PROFESSOR OF ANESTHESIOLOGY,

FOM, KING FAISAL UNIVERSITY.


What is meant by SICU?

A tertiary care facility in the hospital that provides a state of the art medical care to critically ill patients referred to it via different surgical disciplines.


Indications for SICU admission: Pre and post-operative patients of ASA IV and V,

undergoing major and ultra major surgeries. All craniotomy patients. All thoracotomy patients. All ultra major surgeries. Unstable multiple trauma patients. Patients with head or spine trauma requiring

mechanical ventilation. Generally speaking, any surgical patient who

requires continuous monitoring, 1:1 nursing and /or continuous life support is a candidate for SICU admission.


The main functions of any ICU is to:Provide optimum life supportand

Provide adequate monitoring of vital functions.


SICU

Monitoring:•CVS•Respiratory•Renal•CNS•Metabolic•Input/ output

Life support:•General•CVS•Respiratory•Renal•CNS•Metabolic


Types of monitoring in the ICU

Physiologic monitoring: its main objective is Assess the functions of the vital systems. Monitor the effects of different therapeutic

interventions on the critically ill, e.g. PA catheter in a CHF patient.

Safety monitoring: its main objective is Warn against serious incidents that can

jeopardize the patients life, e.g.. disconnection alarm in ventilated patients.


Hemodynamic monitoring:

EKG

NIBP

IBP

CVP

PA catheter and PCWP.


EKG

Heart rateHeart rate Cardiac rhythm Cardiac rhythm ((A fully computerized A fully computerized

arrhythmia analysis is now availablearrhythmia analysis is now available)) Conduction defectsConduction defects.. Myocardial ischemia Myocardial ischemia ((SS--T segment T segment

monitoringmonitoring))


The five-electrode system

Allows the recording of Allows the recording of the six standard limb the six standard limb leads leads ((I, II, III, aVR, aVL, I, II, III, aVR, aVL, aVFaVF)), as well as one , as well as one precordial unipolar leadprecordial unipolar lead..

ComputerComputer- - assisted assisted arrhythmia analysis and arrhythmia analysis and SS--T analysis are possibleT analysis are possible..


NON-INVASIVE BLOOD PRESSURE MONITORING (NIBP):

1. MANUAL (RIVA-ROCCI) TECHNIQUE

2. OSCILLOMETRIC BLOOD PRESSURE DEVICES

3. PENAZ (FINAPRES) TECHNIQUE

4. ARTERIAL TONOMETRY

5.PULSE TRANSIT TIME (PHOTOMETRIC METHOD)


NIBP

Manual

Automatic


INVASIVE BLOOD PRESSURE MONITORING (IBP):

An arterial canula is used. A non compliant saline-filled tube is used to connect

the canula to the transducer, to the display. It measures IBP on beat to beat basis.


CENTRAL VENOUS PRESSURE (CVP) AND PULMONARY ARTERY (PA) MONITORING:

Invasive monitoring of the central circulation allows an estimate of cardiac preload.

For access to the central circulation, various sites have been used including IJV, SCV, basilic vein and femoral vein.


CVP AND PA MONITORING, cont.

Anterior and medial approaches to cannulation of the IJVAnterior and medial approaches to cannulation of the IJV..



Design of a routine PA catheterDesign of a routine PA catheter..



CVP and PA catheters can measure: CVP PAP PCWP CO Mixed venous SpO2


Respiratory Monitoring:

Monitoring of lung mechanics in ventilated patients (in-line spirometry):

Two techniques are used: 1.Main stream spirometry. 2.Side stream spirometry.


Respiratory Monitoring (Mechanics cont.)

Inspired and expired lung volumes (VT and MV)are measured.

PIP, Plateau pressure (PP) and Mean airway pressure are measured.

Dynamic lung compliance is calculated as

DLC= VT / PIP

Static lung compliance is calculated as

SLC= VT / PP


Respiratory Monitoring Gas exchange:

ABGs.

Capnography

Pulse oximetry


ABGs An arterial blood sample is used. ABG analysis measures:

PaO2 PaCO2 pH Some machines also measure Hb conc. And SpO2.

Calculated Parameters include: HCO3 Base excess Total CO2 content. SpO2, if not directly measured.


ABGs: Clinical applications:

Assess adequacy of gas exchange.

Assess adequacy of respiratory support.

Know the acid-base status of the individual.

Assess the adequacy of different interventions on acid-base balance.


Capnography

A typical capnogram obtained A typical capnogram obtained during controlled mechanical during controlled mechanical ventilation showing ventilation showing ::

•Inspiratory baselineInspiratory baseline

•Expiratory upstrokeExpiratory upstroke

•Expiratory plateauExpiratory plateau

•Inspiratory downstrokeInspiratory downstroke


Capnography cont.

Its analysis should include the following: Verify presence of exhaled CO2 Inspiratory baseline Expiratory upstroke Expiratory plateau Inspiratory downstroke Check PICO2min and PECO2max Estimate or measure PaCO2 - PECO2max Search for causes of hypercapnia or hypocapnia, if

either is present


CLINICAL APPLICATIONS OF CAPNOGRAPHY One of two sure signs of endotracheal

intubation. Detection of untoward events e.g..

Disconnections or inadvertent extubations. Maintenance of normocapnea Cardiopulmonary resuscitation Weaning from mechanical ventilation Monitoring the nonintubated patient


PULSE OXIMETRY:Spectrophotometry

The present generation of pulse oximeters uses two wavelengths of lightThe present generation of pulse oximeters uses two wavelengths of light: : 660 nm 660 nm ((redred) ) and 940 nm and 940 nm ((near infrarednear infrared). ). The pulse oximeter measures the AC component of the light absorbance The pulse oximeter measures the AC component of the light absorbance at each wavelength and then divides it by the corresponding DC at each wavelength and then divides it by the corresponding DC componentcomponent.. R R = = AC660AC660//DC660DC660 / / AC940AC940//DC940DC940


PULSE OXIMETRY: CLINICAL APPLICATIONS.

The pulse oximeter is the most significant advance in oxygen monitoring since the development of the blood gas analyzer.

Because it is noninvasive and virtually risk free when used properly, the pulse oximeter should be used in all clinical settings in which there is a potential risk of arterial hypoxemia.

It is the only oxygen monitor that provides continuous, real-time, noninvasive data on arterial oxygenation.


TEMPERATURE MONITORING: IMPORTANCE Temperature regulation is crucial to the survival of

intact animals Although uncommon, hypothermia below 32° C is

ominous. Ventricular irritability increases, and if the temperature

decreases to 28° C cardiac arrest is likely. shivering can increase oxygen demand 135% to

468%,when respiratory and cardiovascular systems may be unable to respond normally to increased demand


Sites for monitoring body temperature

1.Oral.

2.Tympanic membrane

3.Esophageal

4.Nasopharyngeal

5.Pulmonary arterial blood

6.Rectal

7.Bladder

8.Axillary

9.Forehead

10.Great toe


Renal Function Monitoring

The three general functions of the kidneys are: (1) Excrete potentially toxic metabolic end products,

(2) Regulate water and tonicity, and

(3) Produce hormones.


Renal Function Monitoring, cont.

Urine Volume: Normal 0.5- 1.0 ml/kg/hr

oliguria: < 0.5 ml/kg/hr

Urine Specific Gravity: is a measure of concentrating/ diluting capacity of the kidney,

Urine Osmolality: urine osmolality of greater than 500 mOsm/kgH2O indicates prerenal azotemia and less than 350 mOsm/kgH2O indicates acute tubular necrosis.


Renal Function Monitoring, cont. Serum Creatinine: 0.4- 1.2 mg/dl. Blood Urea Nitrogen: normal range is 8 to

20 mg/dl. Urinary Sodium: It is traditionally accepted

that a urinary sodium level of less than 20 mEq suggests prerenal azotemia and a level of greater than 40 mEq, acute tubular necrosis.

Creatinine Clearance: Normal 1- 1.5 ml/kg/min.


Life support: General

General body care include:

Regular turning every 1 hour.

Body and mouth hygiene

Bowl and bladder care.

Passive or active physiotherapy.

Adequate nutrition.


Life support: CVS

Hemodynamic manipulation is done to optimize CV function to achieve adequate tissue perfusion.

This is done by: Optimizing preload, input/ output. Optimizing afterload, vasodilators or

vasoconstrictors. Optimizing cardiac contractility, +ve

ionotropes, -ve ionotropes.


Life support: Respiratory

Simple O2 therapy using various O2 masks e.g.. Venturi masks of various FiO2, 21- 60 %, non-rebreathing mask with a reservoir bag give FiO2 > 80 %.

CPAP, BIPAP.

Mechanical ventilation.


Indications for Mechanical Ventilation

A. Respiratory failure Respiratory arrest, the need is apparent If there is rapid deterioration, it is better to intubate

early before the patient's condition worsens, making intubation more likely to be associated with complications

In cases of severe myocardial ischemia, the added work of breathing can substantially worsen ischemia.

In general, a PaO2 < 50 or PaCO2 > 55 while the patient is receiving supplemental oxygen is an indication for ventilatory support.


Indications for Mechanical Ventilation

B. Protection of upper airway

C. Relief of airway obstruction

D. Improved pulmonary toilet

E. Refractory cardiogenic pulmonary edema


Life support: Renal

Maintain adequate fluid and electrolyte balance and correct any abnormalities.

Avoid hypovolemia, hypotension

Avoid use of nephrotoxic drugs especially in those with a compromised renal function.

Use of various forms of kidney dialysis.


Thank you

Health & Medicine

An Introduction To Surgical Icu