SURGICAL EQUIPMENTS – PART 1

FLUID WARMER

Inadvertent peri-operative hypothermia (a drop in core temperature to below 36°C) occurs because of interference with normal temperature regulation by anaesthetic drugs, exposure of skin for prolonged periods and receipt of large volumes of intravenous and irrigation fluids.

If the temperature of these fluids is below core body temperature, they can cause significant heat loss. Warming intravenous and irrigation fluids to core body temperature or above might prevent some of this heat loss and subsequent hypothermia.

Investigators used a range of methods to warm fluids to temperatures between 37°C and 41°C.

LIGHT SOURCE CABLE

IMAGING SYSTEM

•Light source

•Light cable

•Telescope

•Laparoscopic camera

•Laparoscopic video monitor.

EQUIPMENT TROLLEY

LAPROSCOPIC TROLLEY

The mobile laparoscopic video cart is equipped with locking brakes and has four anti-static rollers.

The trolley has a drawer and three shelves

The upper shelves have a tilt adjustment and used for supporting the video monitor unit.

Included on the trolley is an electrical supply terminal strip, mounted on the rear of the second shelf (from the top).

Recently, ceiling mounted trolleys are launched by many companies which are better and consume less space in operation theater.

LAPAROSCOPIC VIDEO MONITOR

•Soulas in France first used television for endoscopicprocedures in 1956. He demonstrated the first televised bronchoscopy. •

•Surgical monitors are slightly different from the TV which we watch at home. Monitor lasts long so a surgeon gets high end product with at least 600 lines resolution.

The size of the screen varies from 8 to 21 inches.

The closure the surgeon is to the monitor, the smaller the monitor should be to get better picture.

GAS INSUFFLATORS

The electronic CO2 Laproflattor is a general-purpose insufflation unit for use in laparoscopic examinations and operations.

Controlled pressure insufflation of the peritoneal cavity is used to achieve the necessary workspace for laparoscopic surgery by distending the anterolateral abdominal wall and depressing the hollow organs and soft tissues..

Insufflation pressure can be continuously varied from 0 to 30 mm Hg; total gas flow rate and volumes can be set to any value in the range 0 to 45 liters/minute.

•Carbon dioxide is the preferred gas because it does not support flaming. It is very soluble which reduces the risk of gas embolism, and is cheap.

Automatic insufflators allow the surgeon to preset the insufflating pressure, and the device supplies gas until the required intra-abdominal pressure is reached.

The insufflator activates and delivers gas automatically when the intra-abdominal pressure falls because of gas escape or leakage from the ports.

Patient safety is ensured by optical and acoustic alarms as well as several mutually independent safety circuits.

The detail function and Quadro-manometric indicators of insufflators are important to understand the safety point of view.

The important indicators of insufflators are preset pressure, actual pressure, flow rate, and total gas used

Quadro manometric Indicators.

Quadro-manometric indicators are the four important readings of the insufflator.

The insufflator is used to monitor
•    Preset Insufflation pressure,
•    Actual Pressure
•    Gas flow rate and
•    Volume of gas consumed

The preset pressure ideally should be 12 to 15 mm of Hg. In any circumstance, it should not be more than 18 mm of mercury in laparoscopic surgery.

This is the actual intra-abdominal pressure sensed by the insufflator. When veress needle is attached there is some error in actual pressure reading because of resistance of the flow of gas through the small caliber of veress needle. Since continuous flow of insufflating gas through veress needle usually gives an extra 4 to 8 mm Hg of measured pressure by insufflator

If there is any major gas leak actual pressure will be less and the insufflator will try to maintain the pressure by ejecting gas through its full capacity.

Actual pressure if more than 20 to 25mm of Hg has the following disadvantage over the hemodynamic status of the patient.
Decrease venous return due to vena cava compression leading to

  1.  Increased chance of DVT (Deep vein thrombosis of calf)
  2.  Hidden cardiac ischemia can precipitate due to decreased cardiac output
    •  Decrease tidal volume due to diaphragmatic excursion
    •  Increase risk of air embolism due to venous intravasation
    •  Decreased Renal perfusion

FLOW RATE

This reflects the rate of flow of CO2 through the tubing of the insufflator. When veress needle is attached the flow rate should be adjusted for 1 liter per minute. 

When initial pneumoperitoneum is achieved and the cannula is inside the abdominal cavity the insufflators flow rate may be set at maximum, to compensate for the loss of CO2 due to the use of suction irrigation instrument.

This should be remembered that if the insufflator is set to its maximum flow rate 

No matter how much flow rate you set for veress needle, the eye of the normal caliber veress needle can give way CO2 flow at a maximum 2.5liter/minute. When the flow of CO2 is more than 7 liters/minute inside the abdominal cavity through a cannula

TOTAL GAS USED

This is the fourth indicator of the insufflator. Normal size human abdominal cavity needs 1.5 liter CO2 to achieve intra-abdominal actual pressure of 12 mm Hg.

In some big size abdominal cavity and in multipara patients sometimes we need 3 liters of CO2 (rarely 5 to 6 liters) to get the desired pressure of 12mm Hg.

Whenever there is less or more amount of gas is used to inflate a normal abdominal cavity, the surgeon should suspect some error in the pneumoperitoneum technique.

These errors may be a leak or maybe pre-peritoneal space creation or extravasations of gas.

•It is clear and easy to say that, life, recently, is impossible without light, and simply: no light, no laparoscopy.

The light source is the often-overlooked soldier of the video

Laparoscopic system.

•High-intensity light is created with bulbs of halogen gas, xenon gas or mercury vapor.

The bulbs are available in different wattages” 150 and 300 Watt” and should be chosen based on the type of procedure being performed.

Because light is absorbed by blood, any procedure in which bleeding is encountered may require more light.

We use the stronger light sources for all advanced laparoscopy. Availability of Light is a challenge in many bariatric procedures where the abdominal cavity is large

A good laparoscopic light source should emit light as much as possible near the natural sun light.

Three types of light source are in use today:

1. Halogen light source

2. Xenon light source

3. Metal halide light source

A typical light source consists of:

•A lamp (bulb)

•A heat filter

•A condensing lens

•Manual or automatic intensity control circuit (shutter).

BULB

•I-Halogen Bulbs (150-watt) or Tungsten-halogen Bulb •II-Xenon Lamps (300-watt) •III-Metal Halide Vapor Arc Lamp (250-watt)


to be continue……… in part 2

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