VOL: 96, ISSUE: 37, PAGE NO: 3
Sarah Avery, RGN, is a ward manager, Glenfield Hospital, University Hospitals of Leicester NHS Trust
Chest drains are used to manage various thoracic conditions by safely removing air (pneumothorax) or liquid (haemothorax, pleural effusion) from the pleural cavity, preventing it from being reintroduced and enabling the lungs to expand (Welch, 1993).
Many decisions related to their use appear to be based on personal preference rather than clinical evidence, and complications are more likely if the nurses caring for patients with chest drains do not have the necessary skills and training (Tang et al, 1999).
The drain site is determined by whether air or fluid is to be cleared from the pleural space.
Air tends to rise to the apex of the lung and is therefore most efficiently removed when the tip of the drain is anterior and apical to the chest cavity.
Conversely, fluid tends to collect at the base of the lung and is most efficiently removed when the drain is posterior and basal to the chest cavity (Graham, 1996).
Nurses are usually responsible for assembling the necessary equipment (Box 1) and explaining the procedure to patients, preparing them and providing them with constant reassurance, particularly during insertion of the drain.
Positioning the patient
Chest drains are inserted by medical staff under aseptic conditions while the patient is in an upright position.
Patients can be made reasonably comfortable sitting on the edge of a bed with their arms crossed and raised to chin level, their head and arms resting on a pillow placed on a bedside table. Alternatively, they can sit upright in bed, resting back on the pillows with the appropriate arm raised above the head.
The proposed site is cleaned with an iodine-based antiseptic solution before the surrounding area is covered with sterile drapes, leaving only the insertion site exposed.
Local anaesthetic is then injected around the insertion site. When it has taken effect, a 2-3cm incision is made in the skin. Forceps are then used to penetrate through the intercostal muscle and into the pleural space. The proximal end of the drainage tube is clamped with the forceps and inserted into the pleural space. The chest drain can then be connected to the drainage tubing and bottle.
An anchor suture is inserted to secure the drain and a purse-string suture should be placed at the incision site, with the ends left loose so that they can be tied when the drain is removed (McMahon-Parkes, 1997). A dry, non-adherent dressing with an adhesive border is applied over the site and the chest-drain connection is secured with tape.
A chest X-ray must be performed after the insertion of a chest drain to confirm that it has been placed correctly.
Routine observations - blood pressure, pulse, respiration rate and oxygen saturation - should be carried out before and after the procedure so that they can be compared. They should also be monitored at regular frequent intervals if the patient’s condition is unstable.
The insertion of a chest drain is a painful procedure. Tomlinson and Treasure (1997) recommend that 10ml of 2% lignocaine should be used as a local anaesthetic, remembering that it takes from two to five minutes to take effect.
The British Thoracic Society guidelines on the management of spontaneous pneumothorax (Miller and Harvey, 1993) state that the doctor should prescribe adequate analgesia, oral or intramuscular, to be administered while the drain remains in situ.
Securing the chest drain
Current recommendations on taping the connection between the chest and drainage tubes conflict. Some practitioners tape the connection to secure it and avoid inadvertent disconnection, while others say taped connections that become disconnected are not always visible, allowing air to enter unnoticed (Godden and Hiley, 1998).
Neither opinion is evidence-based, so it is advisable to secure the connection with impermeable adhesive plastic tape while maintaining visibility.
A strip of tape can also be used to support the tubing against the patient’s side. This reduces movement at the site and prevents pulling, which can cause pain.
Position and fluid level
Underwater sealed drainage operates as a one-way valve: air can bubble out through the water during expiration or coughing but cannot be drawn back into the chest during inspiration. The fluid level should be checked regularly and the amount, colour and consistency of any drainage noted.
The drainage bottle must be kept below chest level to prevent fluid re-entering the pleural space. There must also be enough water in the bottle to ensure that the end of the tubing is never exposed to air as this could then enter the pleural space
The level of water in the tubing will fluctuate as the patient breathes. A gradual decrease in fluctuation may indicate lung re-expansion but a rapid decrease suggests that the tube is blocked, perhaps with fibrous tissue from the chest cavity.
Patients with a chest drain should be encouraged to maintain an upright position and to mobilise as this increases the use of their lungs, enhancing chest expansion. Deep breathing and coughing raise intrathoracic pressure and promote pleural drainage (Erickson, 1989).
Drainage bottles must be clearly labelled and the amount of fluid they contain should be noted on the patient’s fluid-balance chart. How often the drainage needs to be recorded varies, depending on each patient and the amount of fluid he or she can be expected to lose.
The frequency of recordings can usually be determined according to the patient’s diagnosis. For example, the fluid drained from a patient with a pneumothorax may need to be measured and recorded only every four hours, as a relatively small loss can be expected. But medical staff should be present to monitor fluid loss in patients with a pleural effusion as it is usually rapid and can lead to complications.
Maintaining a 24-hour record of drainage will also help to determine when a chest drain may be removed.
Low-grade suction can be used to aid the removal of air or fluid from the chest cavity. Applying suction to remove intrapleural air can resolve a pneumothorax more quickly, reducing the length of time the drain has to remain in place and therefore the patient’s hospital stay.
There is no consensus on how much suction should be applied, although the most commonly used pressure is about 5kPa.
Too little suction will prevent lung expansion, increasing the risk of a tension pneumothorax, fluid accumulation and infection. Too much can perpetuate an air leak and cause air stealing, where the flow of air through the lung and into the drainage system is too rapid for adequate oxygenation to occur. This can lead to hypoxia and result in portions of lung becoming trapped in the drain (Tang et al, 1999).
Regular inspection is vital to ensure that the suction tubing is patent and set at the correct pressure. The tube should be long enough to allow the patient as much mobility as possible.
Changing dressings and bottles
If a chest drain has been sutured in place correctly air should not leak from the site and an airtight dressing will not be necessary. A small, dry non-adherent surgical dressing with an adhesive border should be sufficient and heavy strapping should be avoided as it restricts chest expansion (Welch, 1993).
The site should be checked every day, and if the dressing is clean and dry it will need to be changed only every 48-72 hours.
How often the drainage bottles need to be changed depends on:
- The condition being treated and the amount of drainage that can be expected;
- The manufacturer’s recommendations.
A study by Huang et al (1999), which looked at chest drainage and pneumothorax, found no significant differences in infection rates or length of stay between patients whose drainage bottles were changed every 72 hours and those whose bottles were changed every 24 hours.
Drainage bottles may need to be changed more frequently, however, depending on the volume of fluid drained. And if the exudate is infected the bottle should be changed according to need as it may be unpleasant for patients to look at and may smell offensive.
Clamping prevents air or fluid from entering the pleural space, but if there is an air leak it can lead to a tension pneumothorax. For this reason, a bubbling chest drain should not be clamped (Harriss and Graham, 1991).
There should also be no need to clamp the tubing if care is taken when mobilising and transporting patients and the principles of good chest-drain management are adhered to.
Drains should be clamped close to the chest wall only when changing bottles or after accidental disconnection, and they should be unclamped as soon as possible (Brandt et al, 1994).
Kinked or blocked tubing can cause a tension pneumothorax or surgical emphysema.
A tension pneumothorax, which can be life-threatening, occurs when air enters the pleural space during inspiration but cannot escape during exhalation. The increasing volume of trapped air collapses the lungs and compresses the soft tissues in the chest.
Surgical emphysema, which causes a crackling noise when the skin is touched, indicates the presence of air in the soft tissue outside the chest. It can make the arms, chest and neck swell, and in severe cases cause facial swelling to the extent that the patient’s eyes may be forced to close.
Although this condition is distressing and frightening for patients, it is not life-threatening. Nothing can be done to reduce the swelling and it may take several days to go down, but the siting of an additional chest drain should prevent it from getting worse.
Fluid-dependent loops in the tubing may also impede drainage. If a dependent loop cannot be avoided, lifting and draining the tube every 15 minutes should help to maintain adequate drainage (Schmelz et al, 1999).
Ideally, the tubing should be laid horizontally across the bed or chair before dropping vertically into the drainage bottle. The length of the tube should be tailored to each patient’s needs, allowing enough to stand up and lie down in bed but preventing the formation of loops.
If the tube becomes blocked, milking it by hand or with a mechanical roller can be harmful as even a small amount of negative pressure can result in lung tissue being sucked into the chest drain (Welch, 1993).
If the blockage is between the chest drain connection and the bottle the tubing should be replaced, eliminating the need to milk it.
Chest drains are removed when drainage and fluid fluctuations have stopped, breath sounds have returned to normal and a chest X-ray shows that there is no air or fluid in the intrapleural space. The removal of a drain requires two members of staff: one to remove the drain quickly while the other ties the purse-string suture.
Removing a chest drain can be a painful procedure, which is often described as a stinging or burning sensation, so analgesia should be administered beforehand and given time to take effect. The type of analgesia required should be determined after careful assessment by nursing and medical staff and in accordance with the patient’s tolerance of pain while the drain has been in situ.
One of the main complications associated with the removal of a drain is recurrent pneumothorax. This is more likely if the patient breathes in while the drain is being removed.
To prevent this patients should be told to take a deep breath and hold it while the drain is being removed (Gallon, 1998). Alternatively, they may be asked to perform the Valsalva manoeuvre - increasing their intrathoracic pressure by holding their breath while trying to breathe out against a closed glottis - as recommended by McMahon-Parkes (1997)
Patients can breathe normally once the purse-string suture has been tightened and should then be asked to cough so that the nurse can ensure that air cannot be heard escaping from the site.
A suture that has been well sited and safely tied should seal the wound and require only a simple, dry dressing. If air is heard escaping from the site, adhesive skin closure strips should be applied to seal it. Chest drain sutures may be removed five days later.
A chest X-ray should be taken after the drain has been removed and the patient’s respiration rate should be recorded to ensure that a pneumothorax has not recurred.
The site should be checked daily and observed for signs of bleeding, infection or necrosis, which could result if the suture is too tight.
The principles of chest-drain management should be explained carefully to the patient to reduce the risks of treatment (Box 2). This is particularly important if the patient is to be discharged with an ambulatory chest-drain bag in situ. These bags allow greater mobility as they are compact, lightweight and transportable, but they are not suitable for large effusions and suction cannot be applied to them.
There is little literature to support the management of patients with a chest drain, and what there is reflects a diversity of views. Best practice can be achieved only by specialists in this field pooling their expert knowledge and developing protocols that can be accessed by all those caring for patients with chest drains.