Hemodynamic Monitoring In The ICU - Standard Treatment Guidelines

Hemodynamic monitoring is an integral part of ICU care. Need for invasive monitoring should be assessed carefully. Attention to technical details correct interpretation of data, and its application in selecting therapy should be individualized within the clinical context.

Ministry of Health and Family Welfare has come out with the Standard Treatment Guidelines for Hrmodynamic Monitoring In The ICU. Following are its major recommendations.

Case definition

For both situations of care

Basic hemodynamic monitoring: In any Secondary Hospital / non-Metro setup

• Clinical examination- Central and peripheral pulses, Manual blood pressure- look at the trend, compare with patients normal values, capillary refill, core temperature, peripheral temperature at extremities


• Noninvasive- Noninvasive blood pressure, Pulse oximetryplethysmographic signals


• Intraarterial pressure


• Central venous pressure


• Hourly urine output


• Screening Echocardiography


• Base deficit (ABG)


• Central venous oxygen saturation

Advanced hemodynamic monitoring in selected cases: In Superspeciality facility in a Metro location

• These should be initiated in patients on high vasopressors, high ventilator support, compromised cardiac and renal function, and where empirical fluid challenge may be harmful. These modalities include

o Cardiac output- minimally invasive Pulse contour analysis (e.g. Flotrac, PICCO, LiDCO) Esophageal Doppler

• Pulmonary artery catheter

o Pulmonary artery occlusion pressure

o Continuous cardiac output

o Continuous mixed venous oxygen saturation (SvO2)

o Derived and calculated variables

o Pulse pressure/ Stroke volume variation

o Continuous Scvo2 monitoring

o Lactate levels

Standard Operating Procedure

*Situation 1: At Secondary Hospital/ Non-Metro situation: Optimal Standards of Treatment in Situations where technology and resources are limited

Arterial Cannulation

The ability of invasive blood pressure monitoring to identify beat to beat variability and long term trends is unsurpassed by any other currently available technology. In addition, presence of arterial catheter enables frequent sampling of arterial blood without arterial punctures in critically ill patients.

Indications

a) Hemodynamic monitoring

- beat to beat monitoring of blood pressure

• acutely hypertensive or hypotensive patients (shock)


• use of vasoactive drugs


• cardiac and cardiovascular surgery


• induced hypotension

- pulse contour cardiac output monitoring

b) Frequent arterial blood gas sampling: critically ill patients including ventilated patient

c) Arterial administration of drugs, thrombolytics

d) Intra aortic balloon pump use

e) Noninvasive blood pressure monitoring not possible – e.g., too obese, burned extremity

Absolute And Relative Contraindications :

• Severe injury to the limb


• Lack of collateral circulation


• Coagulopathy


• Arteriovenous fistula in the same limb


• Pre-existing vascular insufficiency (Raynaud’s phenomenon)


• History of surgery disrupting lymphatic drainage to that limb e.g., mastectomy with lymph node dissection

Equipment:

• Appropriate intravascular catheter


• Fluid filled noncompliant tubing with stopcocks


• Transducer


• A constant flush device


• Electronic monitoring equipment

Site selection:

• The common sites of arterial line insertion are the radial, femoral, and dorsalis pedis arteries.


• Other sites: axillary dorsalis pedis brachial, ulnar, posterior tibial and superficial temporal arteries

Arterial Cannulation:

• The arterial line can be inserted using a simple catheter-over-needle arrangement (with or without a guidewire) or a set based on the Seldinger technique.


• Doppler or ultrasound can be helpful for difficult line insertion.

Set up of the pressure tranducing system

o The pressure transducing assembly consists of a coupling system, pressure transducer, amplifier and signal conditioner, analog to digital converter, microprocessor which convert the signal received from the vein or artery into a waveform on the a bedside monitor

o The flushing system – is set up using a 500 ml saline bottle encased in a bag pressurized to 300 mm Hg. At this pressure the catheter will be flushed with 3 ml saline per hour and help keep the catheter patent. Heparinised saline is no longer routinely used

The reference point is usually at the level of the heart where the transducer is zeroed.

Resources Required For One Patient / Procedure (Patient Weight 60 Kgs)

Guidelines by The Ministry of Health and Family Welfare :

JV Divatia, Professor & Head, Department of Anaesthesia, Critical Care and Pain, Tata Memorial Hospital, Mumbai

Sheila NainanMyatra, Associate Professor, Department of Anaesthesia, Critical Care and Pain, Tata Memorial Hospital, Mumbai