As far as I am aware, this topic has never come up in the CICM Fellowship written paper; however previously examined trainees report having to discuss ICCs in the viva sessions. Plus, there is this WCA thing which might become more relevant as the trainees joining post-2014 finally outnumber the old cohort. These days, pleural drain insertion is taken quite seriously, and not without reason. Next to arterial line insertion it is probably the most disaster-prone procedure in the ICU, and has the most potential for serious complications.
The purpose of this chapter is to unite the information which is otherwise contained in numerous widely spread-out sources. The main audience would probably be the supervisor of training who, upon arriving at work one morning, is greeted by an enthusiastic trainee brandishing the WCA form and demanding to undergo assessment. The supervisor, unprepared for this and possibly hung over, will be unlikely to agree unless a scripted resource is available for them where all the information necessary to answer the WCA questions is available. This chapter is that resource. All the important areas are covered.
In terms of published evidence, one could do worse than read the ACI Consensus Guideline for pleural drains in adults. Certainly, if you're working in NSW this is actually your practice policy document for chest drain insertion, and you will already be intimately familiar with it. A well-worn copy may be stuffed under your mattress. This document is heavily based upon the British Thoracic Society guidelines (Havelock et al, 2010); in fact whole blocks of text have been lifted from there by the unscrupulous plagiarists at NSW Department of Health. For indications and contraindications of pleural drain insertion, one should turn to the NEJM article by Shelly et al (2007) or the slightly dated by still excellent paper by Miller and Sahn (1987).
Indications for pleural drain insertion
Shelly et al (2007, NEJM) offer an excellent list of indications, which is reproduced here with virtually no modification.
Elective (non-emergency) insertion
Indication for multiple chest drains
These are few:
- Loculated effusion
- An existing drain which is poorly positioned but still somewhat functional (in which case you may wish to leave it in situ until the new drain's position is confirmed
- High-flow bronchopleural fistula (insufficient flow from a single catheter)
- Following cardiothoracic surgery
Contraindications ot pleural drain insertion
There are actually few absolute contraindications to the placement of a pleural drain. According to Miller and Sahn (1987), there are none. Most people would probably disagree; for instance a nicely adherent post-pleurodesis lung would probably be a reason to seriously reconsider it. Alternatively, if you strongly suspect right ventricular rupture or something equally horrible, any attempt to insert a chest drain is really just a time-wasting exercise (a cardiac operating theatre should be readied instead).
Relative contraindications are numerous but all can be summarised as either "there is something in your way that is valuable or dangerous" or "the procedure is pointless". Example of valuable things in the way include abdominal viscera, for example in the case of a large diaphragmatic hernia. Examples of poinlessness include loculated effusions and hepatic hydrothorax, added to the list of relative contraindications by Runyon et al (1986) mainly because it caused "massive protein and electrolyte depletion and death of both patients" according to their case report.
Consent for the chest drain insertion
An appropriate consent procedure would need to include the following important matters:
- Description of the procedure
- Risks and complications of insertion:
- Pain during insertion
- Pulmonary oedema
- Lung injury
- Cardiac or greater vessel injury
- Possible later complications:
- Tube may get kinked or blocked
- Wound infection may occur
- Bleeding from injured intercostal vessels
- Chronic pain from injured intercostal nerves
This information was collected from the QLD Department of Health website, where a comprehensive Intercostal Catheter Insertion Consent Form is available.
Additionally, basic pre-conditions for consent must be demonstrated:
- The patient must be legally capable of giving consent (competent)
- Consent must be informed
- Consent must be specific
- Consent must be freely given
- Consent must cover that which is actually done
In accepting consent from a patient, we operate under the presumption of competence: i.e. patient is over 18 and is “duly qualified: having sufficient, capacity, ability or authority” to give consent. This is tested by the following criteria:
- The patient can understand the relevant information
- The patient is able to appreciate the situation and its consequences
- The patient is able to manipulate this information in a rational gashion, and then make a reasoned internally consistent decision
- The patient is able to communicate this choice to you
Physical environment in preparation for the insertion
. In short, the following are important features of your environment:
- Appropriate sterile and nonsterile equipment, including a tray to prepare it.
- Skilled assistant
- Monitoring equipment
- Facilities to ensure patient comfort during the insertion (at a basic level, their bed)
- Drugs including pre-medication, local anaesthetic, sedation, etc
- An ultrasound machine
- Facility to confirm placement radiologically
These could be considered "essential elements", but of course depending on where you are you may have more equipment and asisstence, or none whatsoever (eg. some sort of nightmarish pre-hospital battlefield scenario where you just have your trusty USMC KA-BAR and a bamboo reed). Furthermore, an "appropriate physical environment" for chest drain insertion is a fairly loose deascription of the situation, and any question like this could theoretically be correctly answered with a statement like "an ambient temperature of approximately 294 K, with a breathable oxygen-rich atmosphere pressurised to approximately 101 kPa".
Intercostal catheter selection
Shelly et al (2007) also has an excellent table for sizing of chest tubes depending on their indication. A simplified version of this is included in the NSW Health ACI guideline (p.9). These tables are remixed and reinterpreted below. In short, the higher the flow you will require, the wider the catheter bore; also the more viscous the fluid you are draining, the wider the bore.
|Indication||Seldinger tube size||Blunt dissction technique tube size|
|Small pneumothorax||Fine bore pigtail||20Fr|
|Large pneumothorax||Standard pigtail (14Fr)
or straight 20Fr tube
|Transudative pleural effusion||Standard pigtail (14Fr)||20Fr|
|Empyema (i.e. thick and viscous)||-||24Fr|
The selection of tubes available ranged from 6-8Fr "fine bore" pigtails such as those favoured by interventional radiologists, through standard 14Fr pigtail catheters such as those available in commonly used kits (eg the Wayne set), to larger non-pigtailed sets still inserted via the Seldinger technique (eg. the Thal kit). The larger tubes require blunt dissection to insert.
Appropriate site of insertion
Features of greatest relevance include the "triangle of safety" and knowing where the neurovascular bundle sits.
"Triangle of safety" is bordered by:
- Lateral border of latissimus dorsi (most of the time, this is the mid-axillary line)
- Pectoral groove, which is the lateral edge of pectoralis major
- 5th intercostal space, which is
- Base of the axilla, which is strictly speaking the skin; realisitcally this border will be the superiormost palpable rib.
There are caveats to this. In the following situations, one may wish to insert a chest drain somewhere else:
- If ultrasound or CT has identified a better position
- If there is breast tissue in the way
- If there is a pneumothorax, the midclavicular line may be better (i.e. an anterior chest drain)
Indeed the ultrasound guidance of chest drain insertion is probably going to become the gold standard as it seems to reduce complication rate in comparison to the blind technique (Jayathissa et al, 2011).
The neurovascular bundle sits on the inferior surface of the ribs. One needs to aknowledge this as a part of knowing the insertion anatomy.
Preparation and positioning of the patient
The NSW Guideline borrows from Havelok et al (2010):
In word form:
- On the bed
- Sitting up 30-45°
- Slightly rotated away from the lesion
- Arm on the side of the lesion behind the patients head ("sunbaking" position)
Another important part of the preparation is the "time out". This is important: you do not want to be known as the guy who punctured the wrong pleural cavity.
Appropriate monitoring for chest drain insertion
SpO2 monitoring is all NSW ACI recommend, beyond "baseline observations". This probaly depends on how you plan to sedate them (clearly, if a general anaesthetic is being planned this changes the requirements somewhat). Neither of the major review articles mention any specific guidelines for monitoring. The Royal Children's Hospital of Melbourne guideline suggests the following (more comprehensive) series of continuously monitored parameters:
- Respiratory rate
- Heart rate (by continuous ECG)
- Blood pressure, serially duing the procedure (NIBP is appropriate)
If one were in an exam situation where one's safety as a practitioner were being assessed, one would want to err on the side of caution by asking for this level of monitoring.
Indications for ultrasound guidance in chest drain insertion
In the British guidelines (Havelok et al, 2010) "thoracic ultrasound guidance is strongly recommended for all pleural procedures for pleural ﬂuid". The local guidelines seem to be significantly influenced by this set of guidelines, and also suggest that "real time bedside thoracic ultrasound guidance is gold standard for the insertion of non-emergency pleural drains for management of pleural fluid". These recommendations are based on the observation that the blind procedure has a 30-40% comlication and failure rate, as compared to virtually 0% for real-time ultrasound.
As for the use of it for pleural fluid - this is theoretically correct, but one can also use ultrasound to identify an area where there is definitely some pneumothorax, and so the use of ultrasound is not limited to fluid collections.
The sterile tray
What might you expect to see on the sterile tray for pleural drain insertion?
One might expect that the range of equipment would vary depending on what exactly you are planning to insert. For instance, there may be a pigtail catheter with a series of dilators, or there may be a huge Kelly clamp and a scalpel. The photograph above depicts one of my more OCD-affected anaesthetic colleagues preparing for pigtail catheter placement, with equipment carefully laid out.
An important point to mention is that the eqipment trolley needs to be prepared immediately before the procedure. Duration of exposure to the room air is directly proportional to bacterial contamination of the equipment (Dalstrom et al, 2008). Therefore the correct answer to the question "what is the ideal amount of time between opening and using the sterile equipment" is in fact "zero minutes".
Scrub for chest drain insertion
When asked "how long should you scrup for a procedure", the savvy trainee will reply "for five minutes, as consistent with NSW Health guidelines" as if this were a surgical procedure in the operating theatre.
- 1 minute pre wash
- 4 minutes (first wash of the day)
- 3 minutes for subsequent washes
- Using antiseptic handwash
The NSW ACI guideline does not specify a duration merely recommending that we "perform hand hygiene: aseptic technique requires operator to use mask, sterile gown and gloves". For those who want to read more, the WHO probably supplies the definitive international document for the rationale behind surgical scrub tecnique (Widmer et al, 2010); the local department policy for some reason appears to have been rescinded (but the old document is still interesting and can be viewed here).
Both the NSW ACI and the 2010 British guidelines recommend full aseptic technique:
- Mask (with eye shield)
- Sterile gloves
- Sterile gown
How frequently is there a chest-drain-associated infection? Apparently, 0.2-2.4% (Havelock et al, 2010). This low rate is attributed to high levels of full aseptic technique implementation.
Antiseptic preparation of the insertion site
How might one prepare the site if chest drain insertion?
- Iodine or 2% chlorhexidine in 70% alcohol (NSW ACI)
- Begin at the site and paint in widening circles
- Allow 3 minutes drying time (also NSW ACI)
The college WCA document also mentions "drying time" which is porbably more relevant in the operating theatre where an incompletely dried 70% alcohol wash might burst into flames at the first touch of the diathermy probe. In summary:
- Allow alcohol-based prep to completely dry
- For most iodine-based products, a minimum drying time of 3 minutes and ideally up to 10 minutes should be used (Yasuda et al, 2015)
All this can be explored in greater detail in the excellent book by Kamel et al (2011). In short:
- No evidence to recommend one antiseptic over another (the major contenders being povidone-iodine and chlorhexidine); however iodine-based solutions can be used on mucous surfaces whereas alcohol-based ones cannot.
- No evidence to recommend any specific technique of site preparation (pain, scrub, etc)
Sterile barrier and appropriate drape for chest drain insertion
The local guidelines merely say "drape widely". What could that mean? Without any published recommendations, one may rever to the basic principle that one will never be criticised for taking aseptic technique too seriously. Thus:
- Place the drape nearest to you first
- Place drapes to cover the patient to witin your arm's reach
- Drape all of the patient's un-prepped skin with a fenestrated drape
This would be determined by the level of pre-existing sedation (eg. deep sedation and paralysis vs. a wide awake patient) and by the technqiue (pigtail vs. large bore). Basic principles:
- Ensure some analgesia is available if necessary (eg. entanyl is loaded into a syringe)
- Ensure the need for sedation/analgesia has at least been contemplated at some level
- Use local anaesthetic irrespective of the level of sedation
Safe doses of local anaesthetic agents
Generally speaking we all end up using lignocaine (1% or 2%), for which the safe dose without adrenaline is 3-4mg/kg. However, in case it is required, here is a helpful table from LITFL, listing some important characterisitics of local anaesthetics:
|Onset (min)||Duration (min)||Max dose (mg/kg)||Max mg (70kg person)|
|Lignocaine (1% or 2%)
|Lignocaine with adrenaline
(1% or 2%)
|Bupivicaine with adrenaline||5||180-420||3mg/kg||225mg|
|Prilocaine (0.5% or 1%)
|2||30-90||7mg/kg||500mg (<70kg)(50mL 1%)|
It should be pointed out that the NSW Health document recommends you wait for a full five minutes for the local anaestehtic to work.
Preparation of equipment
The college WCA form makes a weird statement regaring the trainee being expected to prepare the equipment "with efficient movement and without compromising sterility", which concievable means that they do not position their sterile trolley in some profoundly stupid place where they have to reach across the patient to grab equipment. Nor is it adviseable to use the patient as a table for your equipment, even if they are well sedated and completely draped from head to toe. In short:
- Put the sterile trolley within easy arm's reach
- Make sure you don't touch it after it is sterile
- Order the equipment you are planning to use from left to right, in the same order as you plan to use it.
The main objective for the candidate being assessed is not to look like a buffoon while olooking for some critical piece of equipment halfway through the procedure, or having to walk back and forth across the room to get stuff.
Appropriate use of ultrasound druing chest drain insertion
- Real time ultrasound during the procedure is recommended
- Pre-procedure marking is not recommended, unless it is done immediately prior to the procedure and the patient has not changed their position.
These recommendations are common to both the NSW ACI and the 2010 British guidelines. Additionally, the British guidelines make statements regarding what exactly one is expected to see on ultrasound, and how one ought to react to seeing it. Briefly:
- You should see fluid; OR
- You should NOT see normal lung sliding (or any other organs for that matter)
- The fluid should be at least 10mm thick
- The entire respiratory cycle needs to be imaged: there should be no lung sliding in the probe's view during maximal inspiration
Anatomical landmarks for puncture or incision
- Use ultrasound to select the ideal intercostal space
- Palpate the rib blow that space
- Use the local anaesthetic needle to infiltrate the space
- Use the same needle to identify the upper edge of that rib
- For a blunt dissection ICC, make an incision along the edge of that rib, approximately 2-3cm long (i.e. long enough to fit your finger)
This image from Miller and Sahn (1987) correctly describes the position of the Kelly clamp in relation to the rib as it breaches the pleura (even though the image suggests that the proceduralist has gained entry to the patient's subcutaneous tissues through some sort of unusual skin flap)
For large-bore chest drain insertion, the recommendation to use blunt dissection is uncontroversial and unanimous (the alternative technique being the use of a trochar).
The ideal instrument should be:
- With a cuved tip
- Toothed, to grip the tube
- Long enough to open to a reasonable maximum width of the jaws
The usual instrument is depicted below (image from Esteem Healthcare) , and seems to be interchangeably referred to as a Kelly artery forceps or a Spencer-Wells clamp.
Using this thing, "a path is made through the chest wall by opening the clamp to separate the muscle ﬁbres". There does not seem to be any specific guidelines for a particular technique.
Identification of the pleural space and avoidance of lung injury
For pigtail insertion, this consists of:
- Aspiration of air or pleural fluid from the 21g local anaesthetic needle
- Aspiration of air or pleural fluid from the pleural drain needle (usually 18 or 16G)
- Unimpeded insertion of the soft J-tipped Seldinger wire
For large-bore ICCs, this consists of:
- Blunt dissection under direct vision
- Finger thoracostomy and identification of pleural contents
- "Finger sweep" to identify adhesions around the site of thoracostomy
- Unimpeded insertion of the chest drain tube
In addition to these, safety issues can be mentioned:
- Do not proceed with insertion if fluid or air is not seen, or if it cannot be aspirated
- Do not force the guidewire or the ICC if it is not moving easily
- Do not introduce the dilator (or pigtail needle) beyond 1cm into the pleural space
Safe drain insertion and confirmation of intrapleural placement
This can be assumed if fluid other than blood or bile comes out, or if there is a good air leak. More formally, the correct position of the drain can be confirmed in a variety of ways:
- Aspiration of the expected pleural content
- Visualised condensation on the inside of the tube (due to the warm humid air from the chest cavity)
- Drain position in relation to the skin (black marks on the pigtail, or numbers on the ICC, and making sure all of the side holes are inside the chest cavity)
- By percussion and auscultation of the affected hemithorax
- By the auscultated sound of suction (when this drain is placed on suction)
- By improvement of gas exchange and/or haemodynamics
- By the oscillation of the fluid in the drain
- By bubbling in the underwater seal
- Chest Xray
- Ultrasound (Jenkins et al, 2012)
Appropriate drainage devices
These are discussed in the chapter on underwater seal drains. In short:
- The basic requirement is a one-way valve of some sort
- The valve needs to let stuff out, but not let anything in
- In virtually every circumstance, the appropriate device which satisfies this requirement is a three-bottle underwater seal drain.
- In a few circumstances a Heimlich valve may be appropriate.
The standard bottle drain system can be ornamented with clamps, valves and digital devices, with various advantages. For instance, it might be interesting or useful to be able to accurately quantify the leak, and have it graphed over time. Zisis et al (2015) wrote a good overview, for people who would dare to read more broadly about such things.
Immediate care of the chest drain insertion site
It is important to secure the drain. This is done by a variety of different techniques.
- An occlusive dressing is usually placed over the wound
- There is a variety of commerically available dressings precisely for this purpose.
- An ideal dressing remains transparent so that the wound can be inspected
- The wound will need to be sutured to close the edges, as well as to hold the drain in place.
- On an unrelated matter, multiple drains should be labelled.
- The ideal suture material is one which grips the drain like a braided suture, but which is resistant to infection like a monofilament plastic.
- Needless to say, the suture should be non-absorbable.
- The ideal technique has never been identified by any sort of clinical trial
- Havelock et al (2010) report that usually a horisontal mattress stitch is used to hold the wound closed in the case of large-bore ICCs
- Usually texbooks recommend purse-string sutures, but apparently this is a bad idea because "they convert a linear wound into a circular one that is painful for the patient and may leave an unsightly scar".
Correct Chest X-ray position of the pleural drain
The correctness of the drain position is really determined by the fact that it has drained something. Ideally, it will have drained the thing you had intended to drain, rather than right ventricular blood. When this criterion is satisfied, the radiological drain tip position is academic.
Important radiological issues still remain:
- The drain has a radio-opaque line along it, which is interrupted at the sites of the side-holes. All of these should be inside the chest cavity
- The drain should not be visibly kinked
- The drain should probably not be abutting the apex of lung or the mediastinum (it is probably not threatening inthe short term, but it porbably has some sort implications
The NSW ACI guideline makes a few more statements:
- The CXR should be performed within 1 hour
- It should be reviewed within 4 hours
However, if a malposition of the drain is suspected (eg. you think you skewered the diaphragm or punctured the lung) a CT is the gold standard. On CXR, it would be impossible to tell when you are in the lung parenchyma, for example.
Adequacy of drainage
So you think you have it in the right position. What parameters will you use to decide that the drainage is adequate? Specifically this refers to excessive drainage.
- 1.0-1.5L is the maximum hourly drainage rate you should permit
- If you exceed 1.0-1.5L, you may risk re-expansion pulmonary oedema.
- After this volume has been exceeded, NSW ACI recommend to keep the drain clamped for 15 minutes before draining any more.
- For any given situation the NSW ACI guidelines recommend you set some (apparently, arbitrary) output criteria which - if breached- should trigger a phone call.
- In haemothoraces, an excess of 100ml/hr output is concerning, as it may represent an injured intrathoracic vessel or ongoing arterial blood loss
Normally, the pleural cavity contains no more than 4-18ml of fluid, and this fluid turns over at approximately 0.2ml/kg/hr (i.e. a daily rate of around 336ml for a 70kg person). This represents the theoretical capacity of the pleural space to reabsorb fluid. Thus, if the daily drain output is less than this, the drain may be able to safely come out.
The meaning of drain observation findings
What does it mean when the underwater seal has stopped bubbling?
- The pneumothorax has reexpanded
- The tube has become kinked or blocked
- The suction has become disconnected
What does it mean when the drain has stopped "swinging" (oscillating)?
- The tube has become kinked or blocked
- The tube is dislodged
- The lung is re-expanded
Complications of intercostal catheter insertion
Harris et al (2016) have reported on the results of their survey of major complications in the UK. This list was added to the complications discussed by Kesiema et al (2011), which is in fact a comprehensive resource.
|Damage to local structures:
Other adverse events
Horner's syndrome is mentioned: it results from pressure of the tip of the chest tube on the sympathetic chain in the medial portion of the apex of the
Complications of pleural drainage
Rather than complications of the tube insertion per se, these are complications of the drainage process itself
- Retrograde flow of fluid = infection
- Kinking, occlusion, clamping = pneumothorax
- Dislodgement = subcutaneous emphysema
- Post-pneumonectomy suction = dangerous retraction of mediastinal content (see
Question 4 from the second paper of 2009).
- Suction = failure of the bronchopleural fistula to heal
- Reexpansion pulmonary oedema
Management of acute complications
Because the complications are many and usually involving damage to internal organs, any sensible approach to their management includes calling the surgeons at some stage. Some select complications and their management options are listed below, again from Kesiema et al (2011)
|Reexpansion pulmonary oedema||
As with any procedure, the pleural drain should be documented somehow. Local guidelines recommend the following minimum details:
- Sedation given and total volume local anaesthetic instilled
- Depth of insertion and any complications
- Type of tube inserted including serial number and bar code
- Method of drain fixation and wound closure
- Suture or locking mechanisms for removal / to be disabled before removal
These "drain obs" should include the folloing minumum of data:
- Presence of bubbling
- Presence of oscillation
- Draind volume
Additionally, the patient should have a minimum of 4-hourly observations recorded, consisting of:
- Resp rate
- Heart rate
- Blood pressure
- Pain assessment
In short, don't use them.
The British Thoracic Society guidelines only recommend 24 hours of good Gram-positive cover in the case of chest tubes inserted in the context of chest trauma. Apparently, a meta-analysis of 1241 chest drains had found significantly reduced rates of empyema (by two thirds).
Indications for removal
How do you know that it is time for it to come out?
- It is dislodged or has become somehow malpositioned
- The primary problem (effusion, pneumothorax etc) has clearly resolved
- No new emergent problems are anticipated (eg. you aren't planning to insert a subclavian line on the same side this afternoon)
- Bubbling has ceased for several hours
- The daily fluid output has been less than 200ml/day ( this seems to be a safe threshold and is recommended by the BTS, though some studies have demonstrated safe removal at volumes in excess of 400-450ml per day)
- The chest X-ray should demonstrate satisfactory lung reexpansion
Technique of chest drain removal
- Clamping the drain before removal is usually not necessary if the drain output has been low. In fact it is probably contraindicated if the patient is on positive pressure ventilation, because the risk of tension pneumothorax is so great
- Whether to remove the tube at end inspiration or end expiration is not clear. All that matters is that the patient is not inhaling just as the drain his come out (otherwise a pneumothorax may develop because of the air entering through the skin defect). The BTS guidelines previously recommended expiration or Valsalva, but these days only emphasise a lack of evidence to support either.
- Ensure that the tip is intact
- Place an occlusive dressing over the wound
- Use a mattress suture to close if this was a large-bore ICC.
Management of late complications
It would be possible to digress exensively here on the management of "site infection, catheter displacement or erosion including, broncho-pleural fistula, empyema" but it is probably more important that the candidate is able to recall a handful of these, and offer at least one non-idiotic management option.
Indications for and complications of intrapleural firinolytic therapy
Occasionally, one might be tempted to introduce fibrinolytic agents into an empyema cavity in order to destroy the locules and promote drainage. There are a few indications for this therapy:
- Haemothorax (Huang et al, 2016)
- Loculated empyema (Heimes et al, 2017)
- Parapneumonic "exudative" effusion (Janda et al, 2012)
The advantages of this method:
- Avoids additional chest drain insertions
- Prevents throracotomy
- Is possible in patients who would be poor surgical candidates (eg. unlikely to thrive on one-lung ventilation)
- Failure of fibrinolysis
- Temperature elevation
- Bleeding (in 6.6 % as per Abu-Daff et al, 2013)
- In some cases, very severe bleeding eg. from lateral thoracic artery or internal mammary artery branches, requiring urgent intervention.
Accreditation of practitioners and audit practices
As per the local (NSW ACI) guidelines, the following is expected of a practitioner who is competent in the insertion of chest drains:
- Competency is assessed according to the local Clinical Procedure Safety Standard
- Satisfactory theoretical knowledge
- "incremental procedural experience, starting with simulation, models and simple procedures before progressing to complex procedural techniques or applying procedures to patients"
- A Pleural Procedure Training log needs to be maintained
Complications may be audited:
- A Pleural Audit team might independently do this
- The health service should log all complications
- All immediate complications should be reported to the local incident management committee for review
- The incidents should be discussed at regular mortality/morbidity meetings