MIST
MINIMALLY-INVASIVE SURFACTANT THERAPY (MIST)
Exogenous surfactant administered to spontaneously breathing infants on non-invasive respiratory support without the need for intubation.
Introduction
Less intubation in RDS
Surfactant deficiency remains (particularly without steroids)
RHW uses “Hobart method” which involves the administration of surfactant via a semi- rigid catheter briefly passed into the trachea.
EQUIPMENT
Hudson CPAP prongs [Sizes 1 (10fr) – 4 (16fr)]
Atropine 600 mcg/ml
Layngoscope handle and blade – Miller 0 or 00
BD Angiocath 16G, 1.7 x 133 mm
3ml or 5ml syringe
Vial access cannula
Surfactant
Selection
Preparation
1) Intubation trolley prepped incase of emergency
Procedure
1. Continuous cardiorespiratory monitoring
2. Swaddle the infant and administer oral sucrose
+/- Atropine (10microg/kg) IV
3. Position the bed ht, infant (neopuff/monitor visible), shoulder roll
4. Continuous aspiration of NG
5. Perform direct/video laryngoscopy using a standard laryngoscope blade (with CPAP inset if possible)
6. Insert the Angiocath orally, through the vocal cords, to the desired depth, and hold it in position at the lips, remove blade
8. Remove the catheter and continue nCPAP.
Post-procedure
1. Remain with infant until heart rate, oxygen saturations and respiratory effort are close to
baseline values.
2. Restore the infant to their previous position and change the infant’s Hudson CPAP prongs
back to the midline nasal tubing with prongs or mask on the same settings as prior to the
procedure.
3. Document eMR/NICUS/observation chart.
1. Dargaville PA, Kamlin CO, De Paoli AG, et al. The OPTIMIST-A trial: evaluation of minimally- invasive surfactant therapy in preterm infants 25-28 weeks gestation. BMC Pediatr 2014;14:213.
2. Aguar M, Vento M, Dargaville PA. Minimally Invasive Surfactant Therapy: An Update. NeoReviews 2014;15:e275-85.
3. Göpel W, Kribs A, Ziegler A, et al; German Neonatal Network. Avoidance of mechanical ventilation by surfactant treatment of spontaneously breathing preterm infants (AMV): an open-label, randomised, controlled trial. Lancet 2011;378:1627-34.
4. Kanmaz HG, Erdeve O, Canpolat FE, et al. Surfactant administration via thin catheter during spontaneous breathing: randomized controlled trial. Pediatrics 2013;131:e502-9.
5. Kribs A, Roll C, Göpel W, et al; NINSAPP Trial Investigators. Nonintubated Surfactant Application vs Conventional Therapy in Extremely Preterm Infants: A Randomized Clinical Trial. JAMA Pediatr 2015;169:723-30.
Exogenous surfactant administered to spontaneously breathing infants on non-invasive respiratory support without the need for intubation.
Introduction
Less intubation in RDS
Surfactant deficiency remains (particularly without steroids)
RHW uses “Hobart method” which involves the administration of surfactant via a semi- rigid catheter briefly passed into the trachea.
EQUIPMENT
Hudson CPAP prongs [Sizes 1 (10fr) – 4 (16fr)]
- 700-1250 grams 1 (10fr)
- 1250-2000 grams 2 (12.5fr)
- 2000-3000 grams 3 (15fr)
- >3000 grams 4 (16fr)
Atropine 600 mcg/ml
Layngoscope handle and blade – Miller 0 or 00
BD Angiocath 16G, 1.7 x 133 mm
3ml or 5ml syringe
Vial access cannula
Surfactant
Selection
- clinically stable (no apnoeas, HR >120) on nCPAP not likely to require intubation
- Use caution in congenital airway anomalies or other respiratory conditions (eg. pulmonary hypoplasia)
Preparation
1) Intubation trolley prepped incase of emergency
- Laryngoscope +/- a size
- +/- Atropine for MIST, +/- morphine/sux if need to intubate.
- ETs sized/CO2 if need to intubate
- Hudson CPAP prongs (moustache)
- or HF 8L/min if unavailable
- Slight anterior curve (aim is for bend to be at cords during administration)
- Distance from tip to bend
- <1000 grams – 1.5 cm
- 1000-2000 grams – 2.0 cm
- 2000-3000 grams – 2.5 cm
- >3000 grams – 3 cm
- Distance from tip to bend
- Surfactant dose is 200 mg/kg (2.5 mL/kg).
- Draw up an additional 0.5 mL of air
Procedure
1. Continuous cardiorespiratory monitoring
2. Swaddle the infant and administer oral sucrose
+/- Atropine (10microg/kg) IV
3. Position the bed ht, infant (neopuff/monitor visible), shoulder roll
4. Continuous aspiration of NG
5. Perform direct/video laryngoscopy using a standard laryngoscope blade (with CPAP inset if possible)
6. Insert the Angiocath orally, through the vocal cords, to the desired depth, and hold it in position at the lips, remove blade
- Limit time to 30 seconds, if failed, allow recovery on nCPAP, consider abandoning after three unsuccessful attempts.
8. Remove the catheter and continue nCPAP.
Post-procedure
1. Remain with infant until heart rate, oxygen saturations and respiratory effort are close to
baseline values.
2. Restore the infant to their previous position and change the infant’s Hudson CPAP prongs
back to the midline nasal tubing with prongs or mask on the same settings as prior to the
procedure.
3. Document eMR/NICUS/observation chart.
- Not all preterm infants managed on nCPAP stand to benefit from MIST
- Many infants will be well supported by CPAP alone and, conversely, many infants with severe surfactant deficiency will require invasive respiratory support.
- Infants who develop severe respiratory distress syndrome (RDS) should ideally receive surfactant early to gain the most advantage, however, in practice it can be very difficult to predict which infants will require surfactant. Currently, it is felt that consideration of MIST should be coupled with early selection of infants who have significant RDS.
- Published studies of MIST with the use of direct laryngoscopy and tracheal catheterization have used different approaches to premedication but all avoid narcotic medications. The avoidance of narcotic medications does not seem to have been associated with any major deleterious effects in the short term. There is also a theoretical benefit of more effective distribution of surfactant with spontaneous breathing during the MIST procedure, which may be ameliorated by the use of narcotic medications.
- Surfactant dosage in published studies has been either 100 or 200 mg/kg. We have chosen the higher dose of 200 mg/kg as reflux of surfactant into the pharynx around the thin catheter is common
- 200 mg/kg is associated with a more prolonged effect
- Infiltration is generally benign but a large volume of infiltrate can cause a compartment syndrome, compressing nerves and compromising circulation.
1. Dargaville PA, Kamlin CO, De Paoli AG, et al. The OPTIMIST-A trial: evaluation of minimally- invasive surfactant therapy in preterm infants 25-28 weeks gestation. BMC Pediatr 2014;14:213.
2. Aguar M, Vento M, Dargaville PA. Minimally Invasive Surfactant Therapy: An Update. NeoReviews 2014;15:e275-85.
3. Göpel W, Kribs A, Ziegler A, et al; German Neonatal Network. Avoidance of mechanical ventilation by surfactant treatment of spontaneously breathing preterm infants (AMV): an open-label, randomised, controlled trial. Lancet 2011;378:1627-34.
4. Kanmaz HG, Erdeve O, Canpolat FE, et al. Surfactant administration via thin catheter during spontaneous breathing: randomized controlled trial. Pediatrics 2013;131:e502-9.
5. Kribs A, Roll C, Göpel W, et al; NINSAPP Trial Investigators. Nonintubated Surfactant Application vs Conventional Therapy in Extremely Preterm Infants: A Randomized Clinical Trial. JAMA Pediatr 2015;169:723-30.