We designed an updated way to perform INSURE, and we called it: ENSURE (Enhanced INSURE — listed by the French Institute of intellectual property amongst the inventions free to be used without any copyright — n.DSO2020003859, since 7 March 2020). ENSURE integrates state-of-the-art respiratory care principles and standardises crucial points from the original INSURE technique. Currently, in the context of modern neonatal critical care, INSURE presents 4 crucial issues:
Duration: The original INSURE did not have a clear duration, although it should be as short as possible [4, 5].
Monitoring: Modern monitoring to verify intubation and ensure patients’ safety was not formally included in the INSURE technique and need to be considered.
Sedation/analgesia: Clear guidance for sedation and analgesia was not given, and too heavy or too light sedation may cause prolonged ventilation or significant discomfort and its harmful consequences, respectively.
Ventilatory technique: The original INSURE did not consider modern principles of gentle ventilation, which avoids the delivery of large tidal volumes and high peak pressures.
ENSURE addresses all these points considering the more recent knowledge as explained below and in Fig. 1.
ENSURE is a teamwork procedure and should be as short as possible [4, 5] (Fig. 1; online video): the physician intubates the patient, while a nurse helps in the preparation and injects the sedative drugs. It is also important to have a nurse or an assistant timing the procedure from the confirmation of intubation to the extubation. This highlights the importance of short ventilation and raises consciousness on the amount of time passing by. Chronometers are often integrated in the neonatal intensive care (NICU) monitoring system, but a simple watch can also be used. It is important to have a short meeting before the procedure to decide the role of every participant. It is advisable to have a protocol for difficult airway management and good communication in case of emergencies . As for several NICU procedures, appropriate simulation team training may be needed . This latter does not need to be in high-fidelity, as our personal experience during 18 months shows that simple simulations repeated 2–3 times/year are effective . With the use of timers, simulation training and good communication, ENSURE can have a maximal duration of 20′ (see below).
During ENSURE, electrocardiogram, respiratory rate and peripheral oxygen saturation (at least on a pre-ductal site) monitoring are provided. If available, cerebral saturation using near-infrared spectroscopy might also be added to estimate cerebral perfusion and oxygenation, and this may be useful to increase patients’ safety, although it is not mandatory. During such a short procedure, there is usually no need to measure mean arterial pressure (unless continuous measurement through an umbilical arterial line was deemed useful and was already available), as this is known to be unrelated to actual cerebral blood flow. Furthermore, it is crucial to confirm intubation quickly and safely: this shall be done with exhaled CO2 monitoring, which is the gold standard in critical care . Low-dead space, accurate exhaled CO2 detectors are commercially available and should be used to confirm the intubation also in very preterm neonates and do not need to stay in place for the whole duration of ENSURE (Fig. 1; online video). Common tube insertion formulas should be used, and the symmetric thoracic expansion can be quickly verified by auscultation or point-of-care lung ultrasound. These techniques together avoid the need for chest X-rays and unnecessary delays prolonging the procedure.
All surfactant administration techniques require laryngoscopy which is associated with acute cardiovascular effects, such as catecholamine release, systemic and pulmonary hypertension, tachycardia, arrhythmias and, in some cases, increased intracranial and intraocular pressures, which are particularly harmful in preterm neonates during the first week of life. The stimulation by the laryngoscope blade causes these physiologic responses since the supraglottic region is highly reflexogenic [4, 5]. Non-pharmacological sedation and patient positioning are useful to decrease discomfort but need to be coupled with pharmacological sedation to obtain blunted physiologic effects. During ENSURE, discomfort is reduced as much as possible, albeit spontaneous breathing is preserved (or avoided only for a short period), allowing a short invasive ventilation and a quick shift to non-invasive respiratory support. During ENSURE, this is achieved by using drugs such as propofol or remifentanil. While the perfect premedication for neonatal intubation still needs to be determined, these drugs currently seem to have a favourable profile. In fact, they allow spontaneous breathing or can be antagonised, and they have quick onset and reversal. We generally prefer to use propofol, because, according to our experience and pharmacokinetic data, a low dose (1 mg/kg)  is usually sufficient to reach adequate sedation with a good safety (Fig. 1; online video). In fact, at least one physiological study suggests that cerebral saturation and local vascular autoregulation remain intact even if hypotension might occur . Our personal experience is also consistent with these data. If arterial pressure measurements after ENSURE indicate hypotension, it is important to integrate this with the data coming from cerebral oxygenation and point-of-care echocardiography . When it occurs, hypotension is usually mild and transient and needs no treatment. We do not use propofol in patients with high intrathoracic pressure, and we prefer remifentanil or ketamine. Oral intubation is usually preferred as this may allow the use of larger tubes with less leaks and seems associated with less post-extubation atelectasis .
Large tidal volume and/or high peak pressure without positive end-expiratory pressure (PEEP), particularly if delivered for a long time, trigger significant lung injury in several animal models [4, 5]. Therefore, a tidal volume of about 5 mL/kg is currently recommended with adequate PEEP of at least 5–6 cmH2O . Thus, ENSURE includes a short and gentle ventilation provided with volume-targeted (i.e. volume guarantee (VG)), pressure-regulated mode, which allows clinicians to ventilate with less variable tidal volumes. This technique is available in all modern ventilators and is superior to conventional modalities without volume targeting . Surfactant is injected directly into the endotracheal tube without inserting a feeding catheter into it (Fig. 1; online video). VG operates real-time pressure weaning while lung compliance quickly improves thanks to surfactant. Bag ventilation must be strictly avoided if not applied with devices providing PEEP and in-line control of delivered volume and pressure. Immediately after extubation, very preterm neonates are switched to non-invasive positive pressure ventilation (NIPPV) as this technique allows the delivery of higher mean airway pressure, facilitating surfactant spread and reducing extubation failure . If available, flow or neural synchronization are also used, since they can improve patient-ventilator synchrony and ventilation efficiency, as compared to unsynchronised NIPPV. More mature neonates can be extubated on continuous positive airway pressure as they have a lower risk of extubation failure.