Features such as coma or pupil refl exes are unreliable prognostic indicators in the early post-resuscitation phase. Accurate prognostication in an individual patient is rarely possible before 24–72hr. Involve the intensive care unit/critical care unit (ICU/CCU) team early.
Pending this and following ROSC • Ensure that the airway is protected ( b p.324).
• Maintain oxygenation and ventilation. Correct hypoxia and prevent hypercapnoea under ABG guidance (may require IPPV). Use pulse oximetry to monitor SpO 2 non-invasively, titrating inspired oxygen concentration to achieve SpO 2 of 94–98 % .
• In intubated patients, insert an oro- or nasogastric tube to decompress the stomach.
• Obtain a 12-lead ECG and a CXR (check position of tracheal tube, central lines and presence of pneumothorax etc.).
• Optimize cardiac output: inotropes, vasodilators, fl uids and/or diuretics may be needed under haemodynamic monitoring guidance. If the arrest is associated with an acute coronary syndrome, consider immediate thrombolysis and/or coronary revascularization.
• Cerebral blood fl ow autoregulation is defi cient post-arrest. Maintaining arterial pressures ‘normal’ for the patient may prevent hypotensive hypoperfusion. i BP above the normal for the patient may worsen cerebral oedema.
• Seizures aggravate brain injury by i ICP and cerebral metabolic requirements. Treat with appropriate anticonvulsants (as b p.149) and ensure adequate oxygenation and ventilation.
• Measure U&E, Ca 2 + , Mg 2 + , and correct abnormalities appropriately.
• Obtain full blood count (FBC) to exclude anaemia contributing to myocardial ischaemia and to provide an admission baseline.
• Both hypo- and hyperglycaemia compromise neurological outcome.
Monitor plasma glucose concentration regularly and aim to avoid both hypo- and hyperglycaemia (keep the level d 10mmol/L).
• No drug has been shown to improve cerebral outcome following cardiac arrest. The routine use of steroids, mannitol, Ca 2 + channel blockers, etc., is unwarranted.
• When any drug is used, remember that pharmacokinetic profi les are often impaired post-resuscitation. Dose adjustment and careful monitoring are needed.
• Avoid/treat hyperthermia with antipyretic or active cooling.
• There is compelling data to support the early induction of mild therapeutic hypothermia (32–34 ° C) in patients who are comatose following out of hospital VF arrest. Mild hypothermia is believed to be neuroprotective in this situation (and pending more data, may be of benefi t in other situations as well, eg other arrest rhythms, in-hospital arrests, paediatric patients). Cooling may be initiated by external techniques (cooling blankets, water or air circulating blankets) or internally by an infusion of 30mL/kg of 4 ° C 0.9 % saline — liaise with ICU.
Mild hypothermia is typically maintained for 12–24hr.
55
POST-RESUSCITATION CARE
Training
Theoretical knowledge is important, but many of the skills required during the management of a cardiac arrest need expert teaching and supervised practice. Attend an approved Resuscitation Council (UK) Advanced Life Support course (see www.resus.org.uk ) — preferably before starting in the ED.
Central venous access
Indications
Central venous access may be required for:
• Administration of emergency drugs.
• Central venous pressure measurement.
• Administration of IV fl uids, especially when peripheral veins are collapsed or thrombosed. Note : other routes (eg femoral vein) are generally preferable for giving large volumes rapidly.
• Transvenous cardiac pacing.
Choice of vein
The external jugular vein is often readily visible and can be cannulated easily with a standard IV cannula.
The internal jugular and subclavian veins are generally used for central venous access in the ED. Subclavian vein cannulation has a relatively high risk of pneumothorax, so the internal jugular vein is usually preferable, via a ‘high’ approach. When possible, use ultrasound (USS) guidance and the right side of the neck ( d risk of thoracic duct damage). If, however, a chest drain is already in situ, use the same side for central venous cannulation.
The femoral vein is useful for temporary access in severe trauma, burns, and in drug addicts with many thrombosed veins.
Seldinger technique for central venous access
The method of choice, because the relatively fi ne needle d risk of complications such as pneumothorax. The technique involves inserting a hollow metal needle into the vein. A fl exible guidewire is threaded through the needle, which is then removed. A tapered dilator and plastic cannula are inserted over the guidewire and advanced into the vein. The guidewire and dilator are removed, and the cannula secured. Once the cannula is in place, check that venous blood can be freely aspirated and secure the cannula.
Precautions and problems
Central venous access is a specialized technique with potentially life-threatening complications, including: pneumothorax, haemothorax, arterial puncture, thoracic duct damage, air embolism, and infection.
• Expert supervision is essential. Cannulation is particularly diffi cult and hazardous in hypovolaemic, shocked, or agitated patients. In such situations, consider whether it is possible to defer the procedure.
• USS has become widely available and is increasingly used by suitably trained ED specialists. It d complications and failure rates by clarifying the relative positions of needle, vein, and surrounding structures.
Variant anatomy and vein patency can also be assessed by USS.
• Bleeding dyscrasias and anticoagulant treatment are contraindications to internal jugular and subclavian vein access.
• Severe pulmonary disease is a relative contraindication to central venous access, especially by the subclavian route, because a pneumothorax would be particularly dangerous.
57
CENTRAL VENOUS ACCESS
Methods
Use aseptic technique. If possible, tilt the trolley 10 ° head down to fi ll the internal jugular and subclavian veins and d risk of air embolus. After successful or attempted subclavian or internal jugular cannulation, take a chest X-ray (CXR) to check for pneumothorax and the position of the cannula.
External jugular vein
The vein can be seen and felt as it crosses superfi cially over the sternomastoid muscle and runs obliquely towards the clavicle. Gentle pressure on the lower end of the vein will distend it. A standard IV cannula can easily be inserted into the external jugular vein, but passing a catheter centrally may be diffi cult because of valves and the angle at which the vein joins the subclavian vein.
Internal jugular vein
The internal jugular vein runs antero-laterally in the carotid sheath, parallel to the carotid artery, and deep to the sternocleidomastoid muscle. The high approach described has less risk of pneumothorax than lower approaches (Fig. 2.7 ).
• Turn the patient’s head away from the side to be cannulated.
• Identify the carotid pulse at the level of the thyroid cartilage.
• Insert the needle 0.5cm lateral to the artery, at the medial border of sternomastoid muscle.
• Advance the needle at an angle of 45 ° parallel to the sagittal plane, pointing towards the ipsilateral nipple. The vein should be entered at a depth of 2–4cm and blood aspirated freely. If it is not, try again slightly more laterally.
Subclavian vein (infraclavicular approach)
• Turn the patient’s head away from the side of cannulation.
• Identify the mid-clavicular point and the sternal notch.
• Insert the needle 1cm below the mid-clavicular point and advance it horizontally below and behind the clavicle, aiming at a fi nger in the suprasternal notch. The vein is usually entered at a depth of 4–6cm (Fig. 2.8 ).
Femoral vein
Insert the needle 81cm medial to the femoral artery and just below the inguinal ligament, pointing slightly medially and with the needle at 20–30 ° to the skin.
1 Rosen M et al . Handbook of Percutaneous Central Venous Catheterization. W.B. Saunders, London.
2 Cosgriff JH. An Atlas of Diagnostic and Therapeutic Procedures for Emergency Personnel . J.B. Lippincott, Philadelphia.
Fig. 2.7 Internal jugular cannulation. 1
Carotid artery Sternomastoid
muscle
Fig. 2.8 Subclavian vein cannulation. 2 Clavicle
First rib
Superior vena cava
Finger in suprasternal notch Subclavian vein