This lower pressure causes less injury to the lungs of the animals. These results indicate that ITPV can be used to effectively ventilate and oxygenate piglets with meconium aspiration syndrome at lower mean airway pressures and peak inspiratory pressures than conventional ventilation. The lungs of the ITPV animals were less hemorrhagic and had less pathologic evidence of injury than the lungs of the conventionally ventilated animals. These offices play a key role in the investigation of suspicious, unexplained, or unexpected deaths, dissemination of important data to public health entities, and communication with families of decedents. The mean airway pressure ranged from 6.3 +/- 1.1 mm Hg at baseline to 6.8 +/- 2.5 mm Hg at 4 hrs in the ITPV group compared with 5.5 +/- 1.2 mm Hg at baseline to 10.7 +/- 3.4 mm Hg at 4 hrs in the conventional ventilation group (p <. Medical examiner and coroner (ME/C) offices sit at the nexus of forensic sciences and public health. The mean peak inspiratory pressure in the ITPV animals ranged from 17 +/- 2.7 cm H2O at baseline to 16.6 +/- 5.7 cm H2O at 4 hrs compared with 16.5 +/- 2.7 cm H2O at baseline to 31.8 +/- 9.1 cm H2O at 4 hrs in the conventionally ventilated animals (p <. 018) and significantly lower mean airway pressure at 2, 3, and 4 hrs after meconium instillation (p <. The animals in the ITPV group had significantly lower peak inspiratory pressure at 1, 2, 3, and 4 hrs after meconium instillation (p <. Heart rate, mean arterial blood pressure, and arterial saturation were monitored continuously. Ventilatory settings were adjusted as needed to a maximum of: FIO2 1.0, peak inspiratory pressure 40 cm H2O, positive end-expiratory pressure 5 cm H2O, and respiratory rate 80 breaths/min.Īrterial blood gases were taken every 30 mins for 4 hrs and ventilatory settings were adjusted to maintain optimal blood gases. Animals were randomized to either ITPV or conventional ventilation, and settings were adjusted to maintain ideal blood gases, i.e., pH 7.35 to 7.45, PCO2 40 to 45 torr (5.3 to 6 kPa), PO2 80 to 100 torr (10.7 to 13.3 kPa), and SaO2 > or = 90%. Femoral arterial and venous catheters were inserted 5 mL/kg of 20% meconium in normal saline was instilled into the endotracheal tube. Twenty newborn piglets, 2 to 7 days of age, weighing 1.8 to 2.8 kg.Īnimals were anesthetized, paralyzed, intubated, and ventilated. The animal research laboratory at Children's National Medical Center, Washington, DC. These findings suggest that both modes of ventilation may represent powerful new tools in the management of patients with acute respiratory failure.To determine whether intratracheal pulmonary ventilation (ITPV) allows for effective oxygenation and ventilation at lower mean airway pressures and peak inspiratory pressures than conventional ventilation in a piglet model of meconium aspiration syndrome. Maximum benefit appears to occur at high ventilator rates. ITPV and h-ITPV can effectively ventilate and oxygenate rabbits with surfactant-deficient lungs at tidal volumes and therefore pressures lower than required with CMV. Normocapnia was achieved using significantly higher PIP and tidal volume, compared with phase 0 (p <. In phase III, PaCO2 increased (average of 71% for ITPV and 79% for h-ITPV) and pH decreased (p <. Oxygenation tended to improve from phase 0 to the end of phase II. In phase II, it was possible to decrease PIP (average of 37% for ITPV and 36% for h-ITPV) and tidal volume (average of 64% for ITPV and 53% for h-ITPV) without compromising gas exchange (p <.

There was a decrease in PaO2 when switching from CMV to ITPV but not to h-ITPV.

In phase I, no difference in PaCO2 was observed between ITPV, h-ITPV, or CMV. The study consisted of four phases: phase 0, CMV after saline lavage, ventilator rate 30 breaths/min phase I, ITPV or h-ITPV initiated at the same pressure and rate as in phase 0 phase II, ITPV or 1.0 L/min h-ITPV bias flow, with peak inspiratory pressure (PIP) decreased and ventilator rate increased to achieve the lowest tidal volume while maintaining adequate gas exchange and phase III, animals returned to CMV. Surfactant deficiency was induced by saline lavage, and rabbits were randomized to either ITPV or h-ITPV. To study changes in PaCO2 and PaO2 during intratracheal pulmonary ventilation (ITPV) and hybrid intratracheal pulmonary ventilation (h-ITPV) compared with conventional mechanical ventilation (CMV) in a rabbit model of respiratory failure, and to define the technique of h-ITPV that combines conventional mechanical ventilation and ITPV.

Coroner itpv landscape