8. Crises and Other Scenarios in Pediatric Anesthesia

Tom Rawlings¹ and Tom Flett¹

(1)

Department of Anaesthesia and Pain Management, Perth Children’s Hospital, Nedlands, WA, Australia

Tom Rawlings (Corresponding author)

Email: Thomas.Rawlings@health.wa.gov.au

Tom Flett

Email: Thomas.Flett@health.wa.gov.au

Keywords

Pediatric simulationPediatric anesthesia crisis managementPrimary tonsillar hemorrhagePost-extubation stridorCardiovascular collapse during laparoscopy

The successful management of a crisis is a multifactorial process. A combination of clinical skills and knowledge is required as well as the application of robust and effective non-technical skills. These non-technical skills incorporate cognitive and environmental factors to enhance a successful team environment to successfully manage a crisis.

The relevant non-technical skills include:

Leadership and follower-ship
Communication
Situational awareness
Calling for help
Role allocation
Right people, right roles
Avoidance of fixation error

Many experienced clinicians exhibit exceptional non-technical skills that are involuntary and learnt over time. Teaching and training in non-technical skills aim to teach ‘experience’ otherwise gained with time. While there is no substitute for experience, an early understanding of the multiple factors required to successfully manage a crisis allows trainees to work on their areas of weakness. Effective, targeted simulation training can help reduce the gap between the text book and reality. This training is particularly important in preparing for pediatric anesthetic crises because a child’s condition can change rapidly compared to an adult, and team members may be less familiar with children and their management during a crisis.

This chapter describes the practical management of some clinical scenarios in pediatric anesthesia. Some of the scenarios describe urgent situations, while others are less urgent but commonly seen and have the potential to become serious problems if mismanaged.

8.1 Cardiovascular Collapse During Laparoscopic Appendicectomy

An 8 year old boy is undergoing a laparoscopic appendicectomy. He has a two day history of abdominal pain, diarrhea and vomiting. He is otherwise previously fit and well and has never had an anesthetic before. There is no family history of problems with anesthesia.

The patient is intubated and ventilated and anesthesia is being maintained with sevoflurane, air and oxygen after an initial dose of fentanyl 2 μg/kg, propofol 120 mg, rocuronium 20 mg and antibiotic prophylaxis with piperacillin with tazobactam.

Shortly after the first port is inserted and insufflation of carbon dioxide begins, there is a drop in the ETCO₂, tachycardia, desaturation and a fall in blood pressure. Figure 8.1 shows the monitor screen at this time.

../images/467929_2_En_8_Chapter/467929_2_En_8_Fig1_HTML.png — Fig. 8.1

(a) Screenshot of anesthetic monitor displaying vital signs during anesthesia and before surgery has started. (b) Shortly after insufflation of carbon dioxide and creation of a pneumoperitoneum

What will you do?

8.1.1 Discussion

An initial approach to this situation could be to take an ‘ABC’ approach and consider acute ‘B’ Breathing or ‘C’ Circulation issues. The first step would be to ask the surgeon to stop insufflating gas and release the pneumoperitoneum, placing the child onto 100% oxygen and starting manual bag ventilation.

Breathing issues can be eliminated by checking there is no obstruction in the circuit and auscultating the chest to confirm bilateral air entry and normal breath sounds. Causes such as hypoventilation, endobronchial intubation and bronchospasm will cause desaturation, but are unlikely to cause profound, acute cardiovascular collapse. The most likely ‘Breathing’ cause of this scenario is a pneumothorax evolving into a tension pneumothorax from gas insufflation tracking into the pleural space. Pneumomediastinum is also possible but less likely.

Once establishing there is no acute ‘B’ problem a ‘C’ (cardiovascular) issue would be considered. Whatever the cardiovascular cause, initial management should always include asking the surgeon to cease what they are doing, give a fluid bolus of 10–20 mL/kg of isotonic crystalloid, give an alpha-agonist (either metaraminol 5–10 μg/kg or phenylephrine 1 μg/kg) and consider reducing the depth of anesthesia, balancing the management of the problem with the risk of awareness. More potent inotropes such as adrenaline (epinephrine) should be considered if cardiovascular collapse is severe and rapidly evolving. Treatment is required to establish a degree of cardiovascular stability whilst simultaneously attempting to identify the cause of the cardiovascular instability. If the patient continues to deteriorate despite these measures, they are likely to proceed towards cardiac arrest.

There are several potential causes of cardiovascular collapse during laparoscopic surgery. One is excessive gas insufflation and impairment of venous return, particularly if the patient is hypovolemic and has not been fluid loaded before the pneumoperitoneum. The child’s condition should resolve on release of pneumoperitoneum if this was the cause. If so, the pneumoperitoneum could be cautiously reapplied with low inflation pressures (less than 12 mmHg or 1.6 kPa. If the problem persists, consideration should be given to completing the procedure open.

Another possible cause is vagal response from stretching of the peritoneum, but this would likely result in bradycardia associated with cardiovascular instability.

Undiagnosed cardiac defects should always be considered in children, especially if the clinical condition is not improving, or if large volumes of fluid are making it worse. Although unlikely in an otherwise healthy child, acute cardiac failure from an undiagnosed cardiac condition can occur under the physiological stresses of pneumoperitoneum. An echocardiogram or other cardiac investigations could be considered if the diagnosis has not become apparent.

An anaphylactic cause should also be considered. There may be other signs such as rashes and lip or facial swelling, but these are not always present. The initial management is the same as described above, including a fluid bolus, with the addition of IV or IM adrenaline (epinephrine). The dose is based on the severity of the collapse and the speed of its progression (see Chap. 7, Sect. 7.9). Intravenous adrenaline is potent and is best used in a very low dose initially until establishing how the patient will respond. In practice, adrenaline will also need dilution before being given. It is important be clear in your mind how to do this dilution, as it will likely be done under time pressure and stress, and a ten times dose error could have catastrophic consequences. A technique to dilute adrenaline is to take 1 mL of 1 in 10,000 adrenaline (100 μg/mL) and add 9 mL of normal saline to it in a 10 mL syringe. This now creates a concentration of 10 μg/mL. For infants, diluting again by a factor of 10 to create 1 μg/mL is often advised. IV adrenaline has a short half-life and repeat doses may be required. An infusion could be started if there is an ongoing requirement.

Another potential cause of this cardiovascular collapse is gas embolism from carbon dioxide used for insufflation of the pneumoperitoneum. This is another reason for stopping insufflation if is associated with any change in the child’s condition. Gas embolism occurs because the trocar is in an abdominal vein. If possible, the suspected entry site of the gas embolism is flooded with saline, and the patient placed head down. Accessing the heart via the right internal jugular vein to aspirate intracardiac gas can be considered, but is unlikely to remove a significant amount of gas. If gas embolism has been caused by this mechanism there is likely to be significant acute hemorrhage from the associated vascular injury.

Insertion of the trocar and port into the abdomen can also damage a major vascular structure such as the inferior vena cava or the aorta or iliac vessels. There may be blood coming up the port, or blood visible on the laparoscopic camera but it can be concealed and not immediately obvious. If concealed or contained in the retroperitoneal space, the abdomen will continue to distend despite deflating the pneumoperitoneum. An acute, major hemorrhage from these vessels will create a large, ongoing crisis. The abdomen will need to be opened to identify and stop the source of bleeding and to stop it. The role of the anesthetic team is to maintain the patient’s circulating volume and promote coagulation. This will require multiple team members and support, as this is likely to be an ongoing crisis. Activation of the hospital’s critical bleeding pathway will facilitate the rapid supply of blood products.

When it becomes apparent this is the cause of the child’s cardiovascular collapse, several crisis resource management principles become important in managing this scenario:

8.1.1.1 Calling for Help

This should be done early and result in many people to assist you, especially in the initial stages.

8.1.1.2 Leadership and Follower-Ship

Establish a leader or leadership group to assign roles and manage the clinical situation as it evolves. Ideally this person or persons should not be distracted by having to do any tasks during this crisis, although this is not always possible in reality.

8.1.1.3 Communication and the Ability to Communicate

Communication is vital, but the ability to communicate is usually the problem. Too many people, too much noise and excitement can stop vital parts of the process being communicated. This is not an easy problem to solve. Options are:

Asking people to only communicate important information and to be quiet at other times
Politely asking people who have no particular role to leave the theatre
Establish an approach to major hemorrhage scenarios based on action cards. This prevents the need for loud, time consuming role allocation as each individual’s role is on the card; it speeds role allocation, and helps those without a role card to leave the theatre.
Have regular pause and discuss moments. At an appropriate moment silence the theatre and summarize where things are up to. This helps to bring some control and calm to the room and reduces noise; it gets everyone up to date on the clinical situation, and it invites useful suggestions from the room to the leadership group.

8.1.1.4 Use of Cognitive Aids

Bring out the massive transfusion protocol and assign someone to work their way through it. The chances of the leader or leadership group remembering everything on the protocol under pressure is unlikely. This frees up the cognitive load of the leadership group to concentrate on other things.

8.1.1.5 Role Allocation

Several roles are needed, and these roles will include people assigned to:

A, B, D—Airway, Breathing and ‘D’ anesthesia (This can all usually be done by one experienced person).
The patient essentially has a circulation issue but an airway, adequate ventilation and keeping the patient asleep still need to occur. Ketamine with or without midazolam may be appropriate. Muscle relaxation to facilitate ventilation and surgery is important.
C—Almost all the other team members will be focused on supporting circulation.
This will involve personnel assigned to insert lines for transfusion, monitoring and administration of vasoactive agents as well as preparing giving sets and monitoring equipment. The equipment required would include large bore IV catheters, an arterial line and central venous access. Team members could remind each other to gain IV access in the upper limbs when the IVC in the abdomen is damaged, or blood products and medications will extravasate into the peritoneal cavity.