Chest tube drainage of pleural effusions—an audit of current practice and complications at Hutt Hospital

Chest drains are used to manage a range of pleural diseases including empyema, malignant effusion, pneumothorax and trauma.1 The optimal location for drain insertion as described by the British Thoracic Society (BTS) is the ‘Safe Triangle'. This is an area bordered anteriorly by the lateral border of pectoralis major, posteriorly by the lateral border of latissimus dorsi, with an apex in the base of the axilla and a base on the line of the fifth intercostal space1; minimising the risk to the internal mammary artery, muscle, breast tissue and organs.2Potential complications of chest drain insertion include puncture of major organs such as the heart, lungs, liver or spleen, bowel as well as bleeding due to arterial or other major vascular structure perforation. Other important complications include pleural infection, inter-costal neuralgia, re-expansion pulmonary oedema, pneumothorax and subcutaneous emphysema.3Chest drain insertion is a common procedure carried out in general wards by relatively junior medical staff,3 with limited knowledge of anatomy and physiology. Several studies since 2005 have documented the lack of adequate training and confidence in chest drain procedures for junior doctors.4-6International interest in small-bore chest drain complications has intensified following a British National Patient Safety Association (NPSA) Rapid Response Report in 2008 addressing chest drain related patient safety incidents. Twelve deaths and 15 cases of serious harm between January 2005 and March 2008 were described.3Recommendations for the National Health Service included emphasis on clinical governance, technical training, and particular endorsement was given for the use of ultrasound guidance for chest drain insertion. The BTS also reviewed their Pleural Disease Guidelines (originally published in 2003 and since updated in 2010) and a pilot audit of 50 Trusts across the UK was completed in July 2009 to review progress.The audit revealed improved approaches to chest drain insertion safety such as improved access to bedside ultrasound, timing of insertions (less ‘out of hours'), and earlier specialist involvement. Consent practices were found to be inadequate and local auditing was encouraged. In addition, further national auditing was planned for 2010.7 The BTS has since published on their website an audit tool to review chest drain insertions in the NHS.8Prior to 2009, there was relatively little published information on complications related to small-bore catheter use for pleural effusion. A large number of studies cited complications of large-bore drains using blunt-dissection insertion techniques for trauma patients and treatment of pneumothorax, but these studies are not directly applicable to medical patients. An unpublished meta-analysis of complications associated with Seldinger chest drain insertion (serial dilation over a guide wire), involving a review of 12 studies from 1987 to 2008 with a total of 1381 patients9-19 presented at the Royal College of Physicians (London) update in respiratory medicine for general physicians in 2008, has been used for comparison of complication data in this audit.The BTS recently updated it's Pleural Diseases Guidelines, and within this evaluated both large-bore and small-bore chest drain complications separately.1Studies reviewed differ in insertion indications, definitions of complications, tube size, expertise of operators and rates of image guidance. We were not able to identify published studies looking at complications of small-bore chest tubes in Australia or New Zealand.HVDHB is a secondary level care New Zealand hospital, serving a population of 140,000 with 54 general medical inpatient beds. It has no specialist respiratory inpatient service and all medical patients requiring chest drains are managed by the general medical service.Pleural procedures at Hutt Valley District Health Board (HVDHB) were reviewed in late 2008 following an incident of inadvertent perforation of the myocardium with a small-bore chest drain placed for pleural effusion.20 This has been reported to the Ministry of Health as a sentinel event.Actions taken included the review and rewriting of procedural protocols and the introduction of a compulsory training session provided by an outpatient based respiratory physician for those inserting chest drains, as well as the availability of digital images in the procedure room, a move towards routine image guided chest drains, and the undertaking of this audit.The primary objectives of the audit were to review HVDHB chest drain practices including use of ultrasound in drain insertion, to assess the complications, and to compare findings with national and international data. The secondary objective was to address anecdotal report of a high incidence of medically managed patients with small-bore chest tubes for empyema requiring cardiothoracic surgery.Methods We conducted a computer search using ICD10 codes for pleural effusion, tuberculous pleurisy, pyothorax, chylous effusion, haemothorax, unspecified pleural condition, and diagnostic and therapeutic thoracentesis for a 12-month period from December 2008 to November 2009 inclusive. This search identified 140 records. Pleural fluid drainage using techniques other than chest drain insertion, and chest drains placed for pneumothorax were excluded, resulting in 65 chest drain insertions. We obtained data from hospital electronic records and paper-based clinical notes retrospectively. Diagnostic categories were simple parapneumonic effusion, empyema, malignant effusion, heart failure related effusion, exudates not otherwise specified and other/unknown. Laboratory data was also reviewed to clarify the diagnosis. Empyema was defined according to BTS guidelines. We recorded drain types according to the following categories: Unknown, French gauge 6-30, or pigtail catheter. Small-bore tubes were defined as <24 French gauge. We documented the location and success of placement with or without ultrasound guidance as well as number of drain insertion attempts, number of drains inserted per patient, days of drain site use, and drain flushing practices. Complications including pneumothorax, malpositioning, vascular injury, injury to diaphragm, liver, spleen or lung, and death, were recorded. We noted referrals to a respiratory physician or cardiothoracic service and the timing of review and transfer. Transfer outcomes were assessed by accessing electronic records from the receiving hospital. The BTS Pleural Diseases 2003 guidelines2,21,22 available at the time of study, and 2008 NPSA Rapid Response Report served as the basis for guidance of best practice for this audit, as there were no guidelines published by the Thoracic Society of Australia and New Zealand. Data were entered into a Microsoft Excel spreadsheet. Descriptive statistics were used to present demographics and complications associated with chest drain insertions. Complications were compared with the data from the unpublished meta-analysis and Pilot Audit from the NPSA. According to National Health And Disability Ethics Committee Guidelines, this study is considered as an audit primarily carried out for quality improvement activity by the employees of the HVDHB and hence did not require formal ethical approval. Results Forty-nine patients receiving chest tube insertion for intrapleural fluid were identified in the 12-month period. Thirty-five patients received one tube only, 12 received two tubes, and 2 patients had three tubes placed, with a total of 65 insertions. Two sets of paper-based clinical records were unavailable for review, though electronic records were accessed in all cases. Age range at admission was 23 to 89, median age 68 years; 69% were male. More chest tube insertions were carried out during the winter months 37/65 (56.9%) (Figure 1.) Figure 1. Number of chest drains per month (Dec 2008-Nov 2009) Median length of stay for patients with chest tubes was 10 days, with a range of one to 45 days. 52/65 (80%) chest drains were inserted by the general medical service, 6/65 (9%) by surgical or intensive care services, 5/65 (8%) by the Cardiology Service and 2/65 (3%) Older Persons Rehabilitation Service. These comprised six large-bore drains (9%), 37 small and 22 of undocumented size. The undocumented drain sizes are very likely to have been small-bore tubes, as medical services managed all events with undocumented tube size and large-bore drains have not been stocked or utilised by medical teams at HVDHB. Therefore for the purpose of this study all undetermined tube sizes have been considered as small-bore, giving a total of 59/65 (91%). Diagnosis, number of insertions and number of patients are shown in Table 1. Table 1. Chest drain insertion numbers according to diagnostic categories Diagnosis Number of insertions Percentage of total insertions Number of patients Simple parapneumonic 8 12.3 7 Empyema 27 41.5 16 Malignancy 6 9.2 5 Heart failure related 5 7.6 5 Exudate not otherwise specified 10 16.3 7 Unknown 4 6.1 4 Transudate of unknown cause 1 1.5 1 Dressler's syndrome 1 1.5 1 Tuberculosis-associated effusion 1 1.5 1 Intraoperative diaphragm perforation requiring chest drain 1 1.5 1 Intrapleural total parenteral nutrition drainage 1 1.5 1 Total 65 100% 49 Of patients requiring two or more drains, 8/14 (57%) had a diagnosis of empyema. Real time ultrasound or marking the site for best insertion was carried out in 21/59 (36%) of chest drain procedures. No information was available on ultrasound use in six cases. No patients had Doppler analysis for detection and avoidance of vascular structures. Table 2. The distribution of drain site location. Site location was not documented in 47.7% of insertions Location Number (N=65) Percentage (%) Not documented 31 47.7 Image guidance into locule 6 9.2 Left ‘Safe Triangle' 5 7.7 Right ‘Safe Triangle' 8 12.3 Posterior 15 23 From HVDHB data, 25 complications within the listed categories were identified from 65 chest tube insertions. 23/25 (92%) complications occurred in those with small-bore, (including five probable small-bore tubes—i.e. 23 complications of 59 small chest-drain insertions), and 2 large-bore drains had complications (of 6 inserted). There were no deaths. Comparative complications between our cohort and available studies are summarised in Table 3. Table 3. HVDHB complication rate compared to Seldinger chest drain meta-analysis9-19data and NPSA Pilot Pleural Procedures audit Complication HVHDHB complication number and percentage occurrence Meta-analysis patient number with non-weighted average frequency NPSA Pilot pleural procedures audit 2009 Total events 65 (100%) 1381(100%) 68 (100%) Pneumothorax 14 (21.5) † * * Malpositioning 1(1.5) ‡ 671 (1.2) * Lung injury 1(1.5) § * 0 Vascular injury 1(1.5) ¶ * 0 Symptomatic re-expansion pulmonary oedema 1(1.5) 320 (0.9) 1(1.5) Vasovagal reaction 1(1.5) 42 (1.9) * \r\n\r