Transient decrease in PaCO(2) and asymmetric chest wall dynamics in early progressing pneumothorax

Monitoring the respiratory rate by miniature motion sensors in premature infants: a comparative study

OBJECTIVE

Existing respiratory rate (RR) monitors suffer from inaccuracy. The study assesses the accuracy of a novel modality that monitors lung ventilation with miniature motion sensors.

STUDY DESIGN

RR was measured by three methods: impedance technology, motion sensors and visual count, in babies (n=9) that breathed spontaneously or with respiratory support and babies (n=12) that received high-frequency oscillatory ventilation (HFOV).

RESULTS

A line close to equality (slope=0.96, r(2)=0.83) was obtained between the motion sensor and the visual count of the RR with narrow 95% limits of agreements (<14.0 b.p.m.). The relationship between the impedance and the visual count showed a lower correlation (r(2)=0.65) and wider 95% limits of agreements (21.4 b.p.m.). The motion sensor- and the ventilator-determined RRs demonstrated a good agreement during HFOV, whereas the impedance failed to measure the RR during HFOV.

CONCLUSION

Monitoring RR with motion sensors is more accurate compared with the impedance, in infants, in all ventilation modes.

Chest dynamics asymmetry facilitates earlier detection of pneumothorax

Pneumothorax is usually diagnosed when signs of life-threatening tension pneumothorax develop. The case report describes novel data derived from miniature superficial sensors that continuously monitored the amplitude and symmetry of the chest wall tidal displacement (TDi) in a premature infant that suffered from pneumothorax. Off-line analysis of the TDi revealed slowly progressing asymmetric ventilation that could be detected 38 min before the diagnosis was made. The TDi provides novel and valuable information that can assist in early detection and decision making.