INTRAVENOUS ACCESS

Secure intravenous access is needed for all emergency management and should always precede anaesthesia and surgery. With a struggling baby, you may be unable to find a vein. In this case, it may be permissible to give inhalation halothane or intramuscular ketamine.
It is essential that the stomach is empty before starting inhalation induction by mask. This can be done by passing (then removing) a 12–16 FG orogastric tube just before you start. This is a well-tolerated procedure and avoids the catastrophe of regurgitation into an unprotected airway.

HOW TO FIND A VEIN

When access is difficult, make sure you have a good light and an assistant to help you. Ideally, an intravenous cannula should be placed in a vein in the arm that is not over a joint and where fixation is easy, comfortable for the patient and convenient for drug administration and care of the IV site. In shocked patients, such veins may be hard to find.

Often the best veins to use in emergencies are:

Do not attempt the subclavian vein as there is a high risk of pleural puncture.

Femoral vein

If you are right handed, it is easiest to stand on the patient’s right and use your left index and middle fingers to palpate the femoral artery (Figure 13.5). Use a 14, 16 or 18 G (20 G in a child) cannula mounted on a 5 ml syringe.

Figure 13.5
1	Pointing down at 45 degrees to the skin, puncture at a point on the inguinal skin crease, the thickness of the patient’s finger medial to where you feel arterial pulsation.
2	An assistant should apply gentle traction, slight abduction of the leg and prevent flexion at the hip by pressing on the knee.
3	Keeping your left fingers on the artery, probe for the vein while aspirating at each new position. You may feel the point entering the vein or see dark blood fill the syringe, or both. At this moment, you have to decide if the needle tip is in the middle of the vein, just entering or just exiting. Only in the first instance will the cannula slide easily down into the vein. Often you can aspirate blood, but the cannula will not slide down. Do not force it. Go further in with the needle fully inserted, take out the needle and connect the syringe directly to the cannula. Aspirate while slowly withdrawing. With skill, you will get the cannula tip in the vein lumen. At this point, it should enter the vein properly when advanced again. Check for free flow of dark blood with no pressure (that is, it is not in the artery) when the final position has been selected.
4	Tape the cannula securely to the inguinal area, but do not fix the giving set to the leg as it will get pulled out.

Internal jugular vein

The internal jugular vein is the most popular vein to choose in severe shock and CPR as well as for elective major surgery.

There must be a clear indication for such an invasive procedure but, provided you follow the rules, complications should be rare.

Two approaches are possible:

In both cases, the patient should be positioned head down (Trendelenburg position). The ease of successful puncture is directly proportional to the pressure of blood in the internal jugular vein. A patient in hypovolaemic shock should therefore be positioned more head down than one in congestive cardiac failure. The latter may not tolerate a head down position and cannulation can take place on a level bed.

Patients suffering cardiac arrest invariably have distended neck veins and internal jugular vein cannulation is fortunately very easy in these crisis circumstances.

Upper approach

1	With the patient head down, turn the head to the left.
2	On the right sternomastoid muscle, find a point for needle puncture midway between the sternum and the mastoid, on the lateral edge of the muscle. Usually this point will be around the external jugular vein, which should be avoided. According to the circumstances, it may be appropriate to put some local anaesthesia at the puncture point.
3	Use the longest, largest cannula you have (an ordinary IV cannula is only just long enough) 14–18 G, attached to a 5 or 10 ml syringe, and loosen the cannula on the needle to run freely.
4	Holding the plunger between fingertips, puncture the skin and advance the needle at a 45 degrees downward angle, aiming at the right nipple (where it would be in a man). If you are right handed, you must stand well over to the left of the patient’s head to get the correct angle (Figure 13.6).
Figure 13.6
5	Advance with short, sharp stabs while aspirating; after only 2–3 cm depth you should see dark venous blood freely flowing into the syringe. At this point, fix the syringe and needle with the right hand while using your left hand to slide the cannula with a rotating action into the internal jugular vein as far as it will go. It should slide easily.
6	Remove the needle, connect the drip and see if it runs. Flow should be fast although it sometimes pauses when the patient breathes in; this respiratory effect is a sign of hypovolaemia and will stop when you have infused more fluid.
7	Next, drop the bag down below head level and look for dark, undiluted blood running into the set. Do not assume the cannula is correctly placed unless you see this sign. Even then, you should continue to look for swelling in the neck which will indicate that the cannula has come out of the vein.

Reasons for failure include:

If the cannula is in an artery, the drip may run at first if the blood pressure is low, but then backs up the giving set with bubbles seen in the bag as the blood pressure returns to normal.

A misplaced cannula may be in the soft tissues, giving a swelling after a few minutes, or in the pleural cavity. In the latter case, it is possible to infuse litres of fluid into the pleural cavity by mistake. For this reason, always lower the IV bag to check for back flow of undiluted blood (not blood stained IV fluid).

Lower approach

The lower approach (Figure 13.7) is easier, especially if there is a lot of muscle tone, but has a much higher risk of pleural puncture. It should be tried only if the upper approach has failed.

Figure 13.7

Using the same patient positioning as above, identify the triangle made by the sternal and clavicular heads of the sternomastoid muscle, left and right, and the clavicle, below. The internal jugular vein runs downwards just below the skin in this triangle, at the lateral side (below the medial edge of the clavicular head of the muscle). A cannula can be inserted – not more than 2 cm deep – and easily enters the vein at this point. Tests for successful placement are the same as before.

Cannulation of a big central vein is useful for emergencies, but poses more hazards for the patient than a peripheral vein.

Venous cutdown

Venous cutdown (Figures 13.8, 13.9, 13.10) is a useful means of obtaining access to a peripheral vein when percutaneous techniques are insufficient or central lines are not available. The saphenous vein is the most common site of cutdown and can be used in both adults and children.

No specialized equipment is necessary for this procedure. All that is required is:

Figure 13.8
Figure 13.9
Figure 13.10
::	Small scalpel
::	Artery forceps
::	Scissors
::	Wide bore sterile catheter (a sterile infant feeding tube is one alternative).

Make a transverse incision two finger breadths superior and two fingers anterior to the medial malleolus. Use the patient’s finger breadths to define the incision: this is particularly important in the infant or child. Use the sutures that close the incision to tie the catheter in place. Do not suture the incision closed after catheter removal as the catheter is a foreign body. Allow any gap to heal by secondary intention.

Intraosseous puncture

Intraosseous puncture (Figure 13.11) can provide the quickest access to the circulation in a shocked child in whom venous cannulation is impossible. Fluids, blood and many drugs may be administered by this route. The intraosseous needle is normally sited in the anterior tibial plateau, 2–3 cm below the tibial tuberosity, thereby avoiding the epiphysial growth plate.

Figure 13.11

Once the needle has been located in the marrow cavity, fluids may need to be administered under pressure or via a syringe when rapid replacement is required. If purpose-designed intraosseous needles are unavailable, spinal, epidural or bone marrow biopsy needles offer an alternative. The intraosseous route has been used in all age groups, but is generally most successful in children below about six years of age.

Veins in babies and neonates

Finding a vein in a baby can be one of the most difficult technical feats in the entire spectrum of medical practice as well as one of the most distressing for everyone involved.

The anaesthetist usually is called in when everyone else has failed, so there are no easy veins and the child is very distressed by the previous attempts. Intramuscular ketamine, 2–3 mg/kg, is effective in creating the enabling environment for successful venepuncture in calm conditions. It is not a full anaesthetic dose. Wait five minutes before examining the veins.

Preferred approaches are:

The neonate is not fat and has prominent veins on the forearm and hand. The saphenous vein is also usually easy to find. The saphenous vein is invariably anterior to the medial malleolus, even if it cannot be seen or felt, and a cut down here is possible.

Great vein cannulation is difficult in babies because the large head makes the angle difficult. It is not recommended unless no other veins are available, such as after extensive burns.
Fixing the IV placement on a board or card is essential to immobilize limb joints.