This pilot study tests the feasibility of using a computerized ventilator management protocol seeking to encourage lung protective ventilation during the acute phase of ventilation, and esophageal manometry based titration of ventilator settings during the weaning phase of ventilation, for children with acute respiratory failure. The investigators hypothesize that such an approach will reduce time on mechanical ventilation, largely by preserving diaphragm muscle function.

Objectives: This pilot study will help refine a computer based ventilator management protocol which will be used in both acute and weaning phases of ventilation for children with acute respiratory failure. The acute phase protocol is an adaptation of the Acute Respiratory Distress Syndrome Network protocol for pediatrics, and the weaning phase involves an esophageal manometry guided weaning protocol based on effort of breathing. The investigators seek to test the safety and feasibility of the protocol recommendations and the software system , and help determine the potential effect size of the intervention to determine feasibility of a randomized controlled trial. They also seek to determine the feasibility and reproducibility of serial diaphragm ultrasound measurements on mechanically ventilated children.

Study Population: All children intubated and mechanically ventilated in the Children's Hospital Los Angeles Pediatric ICU with an anticipated length of intubation > 48 hours will be eligible, with some exclusion criteria based on ability to perform the measurements.

Study methodology: After consent, an esophageal catheter will be placed. A software management tool for ventilator management will be placed at the bedside for each enrolled patient, and recommendations regarding changing ventilator support will be provided to the clinicians every several hours during both acute and weaning phases. When ventilator support is below a threshold, recommendations will be made to perform spontaneous breathing trials. The clinicians will ultimately decide whether to accept or reject the recommendations, and will evaluate the patient before each potential change to the ventilator. The acceptance or rejection of recommendations will be tracked, and used to refine the intervention. Daily diaphragm ultrasound measurements will also be obtained to monitor diaphragm thickness and contractile activity.

Follow up: Clinical outcomes will be followed while in the ICU including re-intubation, medications administered, and ICU length of stay. No follow up after ICU discharge is planned.

Analysis plans: Data will be used to refine the intervention, test the acceptability of protocol recommendations to bedside providers, and determine sample size estimates for a follow up randomized controlled trial. These analyses will be descriptive. A pilot of 40 patients is anticipated.

Inclusion Criteria:

• Intubated and mechanically ventilated patients in the Children's Hospital Los Angeles Pediatric ICU
• Anticipated length of intubation > 48 hours.
• The primary attending physician approves use of the protocol on the patient.

Exclusion Criteria:

• Corrected gestational age less than 37 weeks
• Contraindications to nasoesophageal catheter placement (nasopharyngeal or esophageal abnormalities) or Respiratory Inductance Plethysmography bands (abdominal wall defects such as omphalocele).
• Significant lower airway obstruction (asthma or bronchiolitis), confirmed by ventilator spirometry

During ICU admission