VOL: 101, ISSUE: 42, PAGE NO: 45
Liz Allibone, BSc, RGN, Cert Health Promotion, is nurse teacher, Department of Nursing Development and Quality, Royal Brompton Hospital, London
The insertion of a chest drain can be a frightening procedure for patients.
Liz Allibone explains the technique of inserting a drain, the nurse’s responsibilities when managing these patients, and emphasises the importance of explaining the process to them and their need for analgesia.
Chest drains are placed in the pleural or mediastinal space to evacuate an abnormal collection of air, fluid, pus or solids that may have collected as a result of injury, disease or surgical procedures (Munnell, 1997; Kirkwood, 2002) (Fig 1). Any abnormal collection of fluid or air in the pleural space can compress the lung, causing it to collapse either partially or fully, which can seriously compromise ventilation and the mechanics of breathing (Allibone, 2003). Insertion of a chest drain will allow drainage of the pleural space and help to restore and maintain the negative pressure between the visceral and parietal pleural membranes, allowing full expansion of the lung (Hyde et al, 1997).
A chest drain is usually attached to an underwater seal drainage system, which acts as a one-way valve allowing fluid and air to leave the pleural space during expiration and coughing but which prevents it from being sucked back in during inspiration.
How are chest drains inserted?
A doctor inserts a chest drain under aseptic conditions. Patients are usually positioned on the bed with their arm on the affected side placed behind their head to expose the axillary area. Alternatively, they can lean over a table covered with pillows for support (Laws at al, 2003).
Insertion of a chest drain is reported to be a painful and frightening procedure, and patients must be given an explanation of what is going to happen and an assurance that they will receive analgesia before the procedure is carried out (Bourke, 2003; Luketich et al, 1998).
The skin where the drain is going to be inserted must be cleaned according to local policy, following which a local anaesthetic is injected around the insertion site.
Once the local anaesthetic has taken effect, the area where the drain is going to be inserted is covered in sterile drapes and an incision is made at the site. The most common position for chest tube insertion is the mid-axillary line, through the position described as the ‘safe triangle’ (Fig 2). This position minimises the risk of damage to structures such as the internal mammary artery and avoids damage to muscle and breast tissue that can result in unsightly scarring (Laws et al, 2003).
Blunt dissection of the subcutaneous tissue and muscle around the pleural cavity is achieved using forceps or the doctor’s finger. Using a trocar (a chest drain with a metal introducer) increases the risk of damage to major organs (Laws et al, 2003; Henry et al, 2003; Hyde et al, 1997), however blunt dissection can be more time-consuming (Munnell, 1997).
Ideally, the position of the tube tip should be aimed towards the apex of the lung for a pneumothorax (air in the pleural space) or towards the base of the lung to remove fluid, for example, blood (haemothorax). However, it is suggested that any position can be effective at draining air or fluid (Laws et al, 2003; Tang et al, 1999).
Box 1 indicates the conditions for which intrapleural drainage is required.
How is the chest drain secured?
Two sutures are inserted: one anchors the drain in place and the other assists with later closure of the wound after removal of the drain. Laws et al (2003) suggest that a mattress-style suture (across the incision) be used for wound closure rather than the traditional purse string suture, which can cause puckering of the skin and unsightly scars.
Current recommendations on taping the connection between the chest and drainage tubes conflict (Avery, 2000; Godden and Hiley, 1998); however, what is known is that without any additional method of security, such as tape, there is a risk of their becoming disconnected. The potential complications of chest drain insertion are summarised in Box 2.
Nurses’ responsibilities when managing a chest drain
It is important that nurses receive appropriate training in the management of chest drains and ensure that patients are cared for safely and competently (Laws et al, 2003)
Observation of the patient
A chest X-ray must be performed after a chest drain has been inserted to verify its correct placement, the degree of re-expansion of the lung and the residual pleural fluid and/or pneumothorax.
The patient’s vital signs must be monitored closely, and respiratory function assessed for signs of improvement or deterioration. Observations should include breath sounds and equality of chest movements, respiration rate, pattern, depth and effort associated with breathing (Mallett and Dougherty, 2000; McMahon-Parkes, 1997; O’Hanlon-Nichols, 1996). If any deterioration or distress is detected, the medical team must be notified at once and another chest X-ray should be ordered.
The patient and the chest drain site should be assessed at least daily for signs of systemic or local infection.
Observations of the drainage system
The drainage bottle must be kept below chest level to prevent fluid re-entering the pleural space. The activity of the chest drain, including fluctuation of the water level in the underwater seal chamber (swinging) and the bubbling of air through the underwater seal, should be monitored (Box 3).
The fluid level in the underwater seal drain should be checked regularly and the level of drainage marked on the bottle each time, as therapeutic decisions are based on the quantity of drainage (Light, 2001) and its colour and consistency. The frequency of recording will vary depending on the condition of the patient and the amount of fluid expected to be lost (Avery, 2000; McMahon-Parkes, 1997).
Immediately after chest surgery the extent of the drainage must be monitored every 30 minutes. Following thoracic surgery, the patient may drain up to 100ml/h of blood and haemoserous fluid for three to four hours. If drainage suddenly ceases, this may indicate that the drain is blocked. If there is an increase in blood and haemoserous fluid this may be an indication of haemorrhage, and the nurse should inform medical staff (Nelson and Tully, 1998).
It is recommended that a large pleural effusion be drained slowly to avoid the risk of re-expansion pulmonary oedema. The reason for this being a risk is not clear, but it may be due to an increased permeability of the pulmonary vasculature or because of the lung re-expanding too quickly. Laws et al (2003) suggest that no more than 1,500ml should be drained at one time, and that following drainage of this volume, subsequent drainage should be reduced to 500ml an hour. However, there is no evidence for what the actual amounts that should be drained at one time should be.
Parkin (2002) suggests that there are no guidelines or protocols for the assessment and management of pain associated with chest drains. However, chest drains can cause pain (Hilton, 2004; Gray, 2000), and inadequate analgesia may inhibit both movement and lung expansion and, consequently, patient recovery (McMahon-Parkes, 1997). Current management regimes include patient-controlled analgesia, paravertebral blocks, non-steroidal anti-inflammatory drugs or transcutaneous electrical nerve stimulation.
Suction and chest drains
Suction may be attached to the underwater seal drain to manage a non-resolving pneumothorax following thoracic surgery or to facilitate drainage of a pleural effusion. Ideally, a high volume /low-pressure system should be used (Henry et al, 2003; Laws et al, 2003; Hyde et al, 1997). There is currently no consensus on how much suction should be applied (Avery, 2000), but the most commonly used pressure is 5 kilopascals (Avery, 2000).
Clamping a chest drain tube can increase the risk of a tension pneumothorax. This occurs when air from the alveoli enters, but cannot leave, the pleural space. The air can build up, causing a mediastinal shift towards the unaffected lung, leading to compression of the vena cava, which is associated with shock and collapse. The condition can be fatal. If bubbling is observed in the underwater seal drain, the chest tube should never be clamped. A non-bubbling chest drain should not usually be clamped except momentarily in the event of its being disconnected, if there is damage to the drainage bottle, or to locate a leak in the drainage system (Henry et al, 2003; Laws et al, 2003; Munnell, 1997; Avery, 2000).
If controlled drainage of a large pleural effusion is required, the drain may be clamped in the initial stages to prevent the risk of re-expansion pulmonary oedema (Laws et al, 2003).
Milking and stripping drainage tubing
Studies have shown that routine milking or stripping of tubing to maintain the patency of the drainage system should be avoided as this increases the negative pressure in the intrathoracic cavity (Kirkwood, 2002). Avery (2000) suggests replacing the tubing if it becomes blocked.
Changing drainage bottles
If too much fluid collects in the drainage bottle, resistance to drainage increases (Munnell, 1997). The force required to overcome the underwater seal increases in proportion to the height of the water column (Compeau and Johnston, 1999). However, there is no consensus about how often the bottles should be changed (Godden and Hiley, 1998). The manufacturer’s recommendations and local policies will need to be consulted.
A one bottle /one chamber device is generally adequate to evacuate an uncomplicated pneumothorax, haemothorax or pleural effusion). However, several drainage systems are available, and some units incorporate two or more chambers in one bottle to separate the drainage fluid from the water seal.
Ideally, the drainage tubing should be laid horizontally across the bed or chair before dropping it vertically into the drainage bottle (Avery, 2000; Munnell, 1997; O’Hanlon Nichols, 1996). This is because looped drainage tubing can impede drainage, so increasing pressure in the tubing, which can lead to a tension pneumothorax or surgical emphysema (air in the subcutaneous tissue) (Kirkwood, 2002; Avery, 2000). The patient can be encouraged to lift the tubing every 15 minutes to promote drainage (Schmeltz et al, 1999).
Mobility with a chest drain
Patients should be encouraged to walk around the ward or exercise around the bed if their drain is attached to wall suction. This facilitates drainage and prevents stiffness of the shoulder joints. Deep breathing exercises and coughing should be encouraged so as to open the airways and increase intrathoracic pressure and promote re-expansion of the lungs (McMahon-Parkes, 1997).
Removal of the chest drain
Chest drains are usually removed when the drainage is less than 100-150ml over 24 hours, breath sounds have returned to normal, bubbling in the underwater seal drain has ceased and the chest X-ray shows that the underlying problem has been resolved. Two nurses must perform the procedure: one removes the drain, the other ties the suture to close the wound.
If the patient has had a pneumothorax, the chest drain should not be clamped when it is removed (Laws et al, 2003).
Analgesia and a full explanation of the procedure must be given to patients.
Before any attempt is made to remove the drain, the position and viability of the suture used to close the wound should be inspected to ensure that it will close the site. If in doubt, the medical staff should be notified, as a further suture may be required before removing the drain (Allibone, 2003).
In order to reduce the complication of recurrent pneumothorax, Valsalva’s manoeuvre can be used. This requires patients to hold their breath and to bear down or try to breathe out against a closed glottis. This increases the intra-thoracic pressure, which reduces the possibility of air re-entering the pleural space through the drain site. The drain can be removed while the patient is holding his/her breath or on expiration (Tang et al, 1999; Miller and Sahn, 1987). However, there is no consensus in the literature regarding the optimum breathing technique. As soon as one nurse has briskly removed the drain, the other nurse immediately ties the suture in order to form an airtight seal. The patient can then breathe normally. A chest X-ray should be performed to check that a pneumothorax has not recurred, and both the patient and the drain site should be monitored closely.
The British Thoracic Society’s guidelines for the insertion of a chest drain are graded according to the available evidence (Laws et al, 2003). It should be noted that 70 per cent of the society’s recommendations are based on grade C evidence (expert opinion only) and that 12 per cent are unsubstantiated. Supporting evidence for chest drain management is therefore limited.