High-dose lidocaine reduces airway mucus transport velocity in intubated anesthetized dogs.

Background: Assessment of mucociliary clearance with displacement of charcoal markers in the central airways needs a bronchoscopic procedure and thus local anesthesia of the upper airways. However, the effects of lidocaine administration on mucus transport in airways are inconclusive. Therefore, detailed information is needed to establish the effects of high- and low-dose lidocaine administration.

Early changes in rat diaphragm biology with mechanical ventilation.

To better characterize the effects of 24-hour mechanical ventilation on diaphragm, the expression of myogenic transcription factors, myosin heavy chains, and sarcoplasmic/endoplasmic reticulum calcium-ATPase pumps was examined in rats. In the diaphragm of mechanically ventilated animals, the mRNA of MyoD, myosin heavy chain-2a and -2b, and sarcoplasmic/endoplasmic reticulum calcium-ATPase-1a decreased, whereas myogenin mRNA increased. In the diaphragm of anesthetized and spontaneously breathing rats, only the mRNA of MyoD and myosin heavy chain-2a decreased.

Detrimental effects of short-term mechanical ventilation on diaphragm function and IGF-I mRNA in rats.

Objectives: Because respiratory muscle weakness appears to play an important role in weaning from mechanical ventilation, we developed an animal model of mechanical ventilation with appropriate controls in order to determine whether 24 h of mechanical ventilation already affected diaphragmatic function.

Design And Interventions: Fifty-two male Wistar rats were randomized into three groups: a non-anesthetized control group (C, n=10), an anesthetized spontaneously breathing group (SB, n=9 out of 26), and an anesthetized and mechanically ventilated group (MV, n=12 out of 16).

Results: After 24 h, in vitro diaphragmatic force was decreased in SB group but even more so in MV group (i.