VentWorld Case Study - Mgmt of Persistent Hypertension in Newborn using HFOV

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MANAGEMENT OF PERSISTENT HYPERTENSION OF PERSISTENT HYPERTENSION IN THE NEWBORN USING HIGH FREQUENCY OSCILLATION
Published March 13, 2001

Joseph D. Limauro M.Ed., R.R.T.
Dartmouth Hitchcock Medical Center Lebanon, NH
www.hitchcock.org/pages/resp2/resphome2.html

Contents (click to jump directly to that section, or scroll down to read the case)

INTRODUCTION
CASE PRESENTATION
FURTHER READING
DISCUSSION

INTRODUCTION

A 38 week newborn was delivered via elective c-section. The infant was large for gestational age weighing 4.0 kg and presented with cyanosis and significant respiratory distress including tachypnia, retractions, nasal flaring and poor oxygenation. The infant required manual ventilation with CPAP via ambu bag. SpO2 remained less than 85% on 100% oxygen. The initial chest x-ray suggested Respiratory Distress Syndrome. There was no maternal history to suggest pneumonia.

CASE PRESENTATION

Figure 1. CXR on Conventional Ventilation
(click to enlarge)

The infant was intubated and given surfactant. Initial ventilator settings were: Pressure Control Mode, rate 40, PIP 26 cmH2O, FiO2 1.00, and PEEP 5 cmH2O.The ABG with these settings was pH 7.43, PCO2 37 mmHg and PO2 58 mmHg.

The infant continued to worsen over the next 4 hours. Ventilator settings were now: Pressure Control Mode, rate 60, PIP 36 cmH2O, FiO2 1.00 and PEEP 5 cmH2O. ABG results on these settings were: pH 7.34, PCO2 44 mmHg and PO2 46 mmHg.

The chest x-ray (CXR) (Figure 1) showed no improvement.

Figure 2. CXR on Initial HFO Settings
(click to enlarge)

Due to the high PIP required with little improvement in oxygenation, the decision was made to place the infant on High Frequency Oscillation (HFO). Mean airway pressure was titrated to achieve SpO2 100%. Settings on HFO were: 10 Hz, Mean Paw 24.5 cmH2O, Delta P 42 cmH2O and FiO2 1.00. ABG results on these settings were: pH 7.42, PCO2 40 mmHg and PO2 94 mmHg.

The subsequent CXR (Figure 2) showed adequate inflation to T-9 (9th rib). The endotrachial tube showed high placement and was advanced 2 cm.

Figure 3. CXR Showing Hyperinflation
(click to enlarge)

Over the next few hours oxygenation remained stable with SpO2 remaining at 100%. A repeat CXR (Figure 3) now showed hyperinflation to T-10 with flattened diaphragms. ABG results were: pH 7.57, PCO2 24 mmHg and PO2 267 mmHg.

Mean Paw was slowly weaned over the next few hours without loss of oxygenation and was now at 23 cmH2O. A repeat CXR (Figure 4) was obtained showing lung inflation back to T-9. Delta P was also weaned during this time and was now 34 cmH2O.

Figure 4. CXR Showing Inflation to 9+ Ribs
(click to enlarge)

Over the next 2 days mean Paw, delta P and FiO2 continued to be weaned successfully. With the infant down to a mean Paw of 14 cmH2O, delta P 22 cmH2O and FiO2 0.30, the infant was returned to conventional ventilation on a Servo 300 on the following settings: SIMV mode, rate 40, PIP 25 cmH2O, FiO2 0.30, PEEP 5 cmH2O and Pressure Support 8 cmH2O. ABG results for these settings were: pH 7.51, PCO2 30 mmHg and PO2 125 mmHg.

Conventional ventilator settings were weaned over the next day and a half. FiO2 was now at room air with ventilator settings: SIMV mode, rate 15, PIP 19 cmH2O, PEEP 5 cmH2O and Pressure Support 8 cmH2O. Ventilator waveforms (Figure 5 below) show good compliance. The infant was successfully extubated.

Figure 5. Servo 300 Waveforms
(click to enlarge)