Incidence, characteristics and risk factors for perioperative cardiac arrest and 30-day-mortality in preterm infants requiring non-cardiac surgery.


This is a retrospective observational study that includes 229 preterm infants (age < 37wk) having surgery from the records of 22,650 paediatric anaesthetics in one large German tertiary hospital over 10 years (2008-18).

30-day-mortality was 10.9% (25/229) and perioperative mortality 0.9% (2/229).

Risk factors for mortality were perioperative cardiac arrest (OR 12.5), low body weight (<1kg OR 26.0; 1-1.5kg OR 10.3); comorbidities of lungs (OR 3.7) and gastrointestinal tract (OR 3.5); sepsis (OR 3.6); afterhours surgery (OR 7.3); emergency surgery (OR 4.5); and pre-existing catecholamine therapy (OR 5.0).

Incidence of perioperative cardiac arrests (POCA) was 3.9% (9 of 229).

Risk factors were congenital anomalies of the airways (OR 4.7), lungs (OR 4.7), heart (OR 8.0), and pre-existing catecholamine therapy (OR 59). Of these 9 POCA cases, 5 had circulatory causes (haemorrhagic or septic shock), 2 dying in theatre and 3 who died in NICU within 30 days. All those who survived had POCA attributed to respiratory causes (blocked ETT, difficult intubation, dislodged ETT and pneumothorax).


Anaesthetising sick and small preterm neonates causes even the most experienced anaesthetist concern.

Risk factors for POCA in children as described in the literature include age <1yr, prematurity, ASA≥3, and emergency surgery. For neonates, risk factors are prematurity, congenital heart diseases (CHD) and other congenital defects. The common theme is preterm neonates. Though there are a few single-centre studies referenced, the multicentre NECTARINE study published recently is the largest to date, including 690 cases of preterm infants. Here 30-day mortality was 2.4% for non-cardiac surgery, there were 8 cases of POCA (1.15%) and no intraoperative deaths.

In this summarised paper, the incidence of POCA and mortality is markedly higher than in other literature, possibly because this was done at a tertiary centre that takes care of sicker and smaller children. With the small sample size of POCA cases (9) and perioperative deaths (2), care needs to be taken in interpretation but none of the factors are surprising. Some of these risk factors can also be interpreted as an expression of the severity of the underlying disease (like catecholamine therapy) rather than causative, and after-hours risk can be explained by either surgical urgency or resource availability. It was relevant that intraoperative shock (haemorrhagic or septic) as a cause of POCA was associated with a 100% mortality rate as compared to respiratory causes.

Understanding perioperative incidence, characteristics and risk factors of premature neonates undergoing surgery is significant for all paediatric anaesthetists. Despite the limitations of this study, it confirms the importance of perioperative assessment, preparation, scheduling of optimal surgical timing, resource management, protocols (like shock, haemorrhage and coagulation) and optimal preoperative stabilization in this high-risk population.

Reviewed by Graham Knottenbelt