A minimally invasive method for clinical trans‐diaphragmatic pressure measurement in anaesthetized dogs. (31st July 2013)

• Record Type: Journal Article
• Authors: Pavlidou, Kiriaki; Savvas, Ioannis; Moens, Yves; Vasilakos, Dimitrios; Raptopoulos, Dimitrios
• Is Part Of: Veterinary anaesthesia and analgesia. Volume 41:Number 3(2014:May)
• Page Start: 278
• Page End: 283
• Publication Date: 2013-07-31
• Subjects: Veterinary anesthesia -- Periodicals; 636.089
• DOI: 10.1111/vaa.12073
• Languages: English
• ISSNs: 1467-2987

Abstract

<abstract abstract-type="main" id="vaa12073-abs-0001"> <title>Abstract</title> <sec id="vaa12073-sec-0001" sec-type="section"> <title>Objective</title> <p>To measure trans‐diaphragmatic pressures, as an indication of diaphragmatic contractility, in anaesthetized dogs breathing normally, or during inspiratory obstruction (Mueller's manoeuvre) in order to assess if the method is practicable for use in clinical circumstances.</p> </sec> <sec id="vaa12073-sec-0002" sec-type="section"> <title>Study design</title> <p>Pilot study.</p> </sec> <sec id="vaa12073-sec-0003" sec-type="section"> <title>Animals</title> <p>Twenty eight client‐owned dogs, ASA I or II, 1–10 years old, 5–30 kg bodyweight, which required anaesthesia for surgery, and were to be positioned in lateral recumbency.</p> </sec> <sec id="vaa12073-sec-0004" sec-type="section"> <title>Methods</title> <p>Following a standardized regimen of premedication and anaesthetic induction, anaesthesia was stabilized and maintained with isoflurane. Two commercially available balloon catheters were introduced orally, and advanced, one into the stomach and one into the mid‐third of the oesophagus. Oesophageal and gastric pressures were measured from these catheters, and trans‐diaphragmatic pressure (P<sub>di</sub>) calculated and recorded continuously. At three separate time points during anaesthesia, for one breath, inspiration was obstructed (Mueller's manoeuvre) and P<sub>di</sub> was measured.</p> </sec> <sec id="vaa12073-sec-0005" sec-type="section"> <title>Results</title> <p>Placement of the catheters in the stomach was not easy, and failed in three cases. In five dogs, their size resulted in failure of correct placement of catheters. Good traces of all three pressures reflecting respiratory cycles were obtained from 20 dogs. During normal spontaneous breathing (mean ± SD [range]) P<sub>di</sub> was 5 ± 2.1 (3–10) mmHg. During Mueller's manoeuvre, P<sub>di</sub> was 14.6 ± 4.5 (9–21) mmHg. Abnormal waveforms were seen included cardiac oscillations (five dogs), inadequate intra‐gastric pressure tracing (one dog), deflections with a double peak (one dog), and multiple artifacts when there was increased heart rate and tachypnoea (two dogs in response to surgery).</p> </sec> <sec id="vaa12073-sec-0006" sec-type="section"> <title>Conclusions and clinical relevance</title> <p>Measurement of trans‐diaphragmatic pressure with balloon catheters was practicable in suitably sized dogs anaesthetized for clinical purposes and might be a useful tool in the assessment of diaphragmatic function. A range of catheters are required if the technique is to work in all dogs.</p> </sec> </abstract>