1995 OPEN FORUM Abstracts
Successful Independent Lung Ventilation In A One-Year Old
Durinda Mullins. BA. RRT; Anna August, MD; George B. Mallory, Jr, MD, James S. Kemp, MD. St. Louis Children's Hospital, St. Louis, MO.
Independent lung ventilation (ILV) has been used to ventilate adult and pediatric patients with unilateral lung disease who were failing conventional mechanical ventilation (CMV). We report the use of ILV in a one year old with chronic obstructive pulmonary disease.
The patient, a 28 week gestation twin born by emergency Caesarian section for placental abruption, was transferred to our institution at one year of age for lung transplant evaluation. His medical history included bronchopulmonary dysplasia with ventilator dependency, herniation of the right lung into the left hemithorax at age 7 months, left lung atelectasis of unclear etiology at age 9 months, tracheomalacia, right ventricular hypertrophy/cor pulmonale, systemic hypertension, and questionable life-threatening events of unclear origin requiring cardiopulmonary resuscitation. At admission, he was mechanically ventilated in SIMV mode, rate 46; tidal volume (TV) 90 cc; 50% FiO_2; and +3 PEEP with a representative arterial blood gas (ABG) of pH 7.38, PCO_2 72, PO_2 53. At our institution, chest CT showed a markedly hyperinflated right lower lobe extending across the midline with atelectatic right upper and right middle lobes, atelectatic left lung, and mediastinal shift to the left. The patient was bronchoscoped 3 times in five days; bronchoscopy revealed severe tracheomalacia with total tracheal collapes 1-2 cm above the carina. During each bronchoscopy, large amounts of yellow secretions were suctioned from the left lung. Post-bronchoscopy chest x rays (CXR) showed increased aeration of the left lung, but within 12-18 hours after each bronc oscopy the left lung again became atelectatic. The decision was made to try ILV to bypass the area of tracheomalacia and reinflate the left lung. The patient was reintubated with 2 endotracheal tubes using an ultra-thin bronchoscope. One tube was passed through the tracheostomy site into the right mainstem bronchus; the other was passed nasally into the left mainstem bronchus. Right lung settings were SIMV mode rate 15, TV 50cc, 60%FiO_2, +2 PEEP, Insp time .3 sec; left lung settings were SIMV mode rate 30, TV 70cc, 60% FiO_2, +6 PEEP, Insp time .5 sec. ABG one hour after instituting ILV: pH 7.44, PCO_2 60, PO_2 61. CXR showed increased aeration of the left lung with decreased hyperinflation of the right lung. Pulmonary function tests on day 3 of ILV showed the following:
Parameter Right lung Left lung
FRC (cc) 130 24
Compliance (cc/cwp) 2.48 .92
Time constant (sec) 3.23 1.04
The patient was maintained on ILV with no change in ventilator settings for 7 days; last ABG was pH 7.41, PCO_2 53, PO_2 65. On day 8 of ILV the two endotracheal tubes were removed and the patient was reintubated with a tracheostomy tube and ventilated at SIMV mode rate 40, TV 90cc, 60% FiO_2, +3 PEEP. ABG after discontinuance of ILV: pH 7.42, PCO_2 51, PO_2 61. CXR showed nearly symmetric lung expansion. Over the next 8 days, ventilator support was decreased to SIMV rate 30, TV 90cc, FiO_2 40%, and +3 PEEP with a representative ABG of pH 7.40, PCO_2 55, PO2 65. The left lung remained inflated on all CXRs after the discontinuance of ILV. On the ninth day after discontinuing ILV, the patient experienced ventricular tachycardia rapidly progressing to bradycardia and asystole from which he was unable to be resuscitated.