The influence of external abdominal and thoracic pressure on the intra-abdominal and intrathoracic pressure, measured by a combined intragastric and intra-oesophageal method van Dun P.L.S.; Putseys H.; Van Alsenoy C.; Serneels S.; Devolder A.; Willemen M.; Vandenbril D.; De Backer W.A. Chair of the Commission for Osteopathic Research, Practice and Promotion Research collaborator at the Free University of Brussels, Faculty of Motor Sciences, Osteopathy Department (Belgium) Biomech’O, 2014

Introduction The mutual relationship between pressure in body cavities and their surrounding body structures is of great importance in the diagnostic and therapeutic process in osteopathy.

Introduction The influence of hypertension (> 12 mm Hg = IAH) in body cavities on overall body physiology is well documented and shows a gradual dysfunction of various systems mainly by influencing the circulation of the respective organs.  cardiovascular  respiratory  splanchnic  renal  neurological  abdominal wall

Introduction Our interest ≠ ACS (> 20 mm Hg IAP) with multi-organ failure but :  sustained functional impairment of overall body physiology (“dysfunctions”) Hodges et al., 1997, 2000, 2007; Smith et al., 2008; Teyhen et al. 2009;... Moderate Elevated Intra Cavitary Pressure Impaired Body Physiology Postural Alterations

Objectives The main objectives of this study are :  to pilot the internal and external measurements  to examine the influence of a well defined external pressure on the abdomen and the thorax on :  intra-abdominal pressure (IAP)  intrathoracic pressure (ITP)

Objectives Further research questions were, to assess :  the minimal external abdominal pressure to cause a change in intra-abdominal pressure (IAP)?  the minimal external thoracic pressure to cause a change in intrathoracic pressure (ITP)

Research Methodology Informed consent incl.: min. 18 years excl.: pregnancy 22 healthy subjects 11 male, 11 female subjects; age: 21-61, mean: 44; mean BMI: drop-outs 20 healthy subjects

Research Methodology A silicon probe with five pressure sensors was used  E: oesophagus (5 cm from the end of the probe)  L: larynx (15 cm)  O: oropharynx (17 cm)  P: palatinum (20 cm)  N: nasopharynx (25 cm)  mark on 60 cm (for positioning)

Research Methodology A silicon probe with five pressure sensors was used  E: stomach  L: oesophagus  O: too much interference of the heart  P: too much interference of the heart  N: too high for registration (pharynx)

Research Methodology Analgesia and dilation of the nostrils with a Xylocain and Epinephrine mixture Analgesia of the pharynx with a Xylocainspray The silicon probe was introduced into the stomach via the nasopharynx

Research Methodology The sensors were attached to a double pressure transducer type RespSponce III, Synetics Medical, Sweden

Research Methodology The sensors were attached to a double pressure transducer all signals were led to a digital convertor and were saved on a computer DI 220; DATAQ instruments inc.,Akron, Ohio, USA;14 BIT, 500hz

Research Methodology The external pressure was measured by means of a sensor (16 to 3 cm with 100 sensors). The measurements were transmitted by means of Bluetooth. RSscan, 100 Hz®, International, Olen, Belgium

Research Methodology All measurements were carried out in supine position. Five non forced expiration apnea of 15 sec were asked to set the baseline.

Research Methodology Minimal external pressure threshold examination An osteopath exerted a gradual external pressure on :  abdomen (umbilicus)  thorax (sternum)

Research Methodology Leaden weights of respectively 1, 3 and 5 kg were placed on the abdomen while measuring intra-abdominal and intrathoracic pressure.

Research Methodology The same procedure was carried out on the thorax

Research Methodology 1.apnea (baseline) 2.minimal external pressure threshold abdomen 3.1 kg abdomen 4.3 kg abdomen 5.5 kg abdomen 6.minimal external pressure threshold thorax 7.1 kg thorax 8.3 kg thorax 9.5 kg thorax

Results t-values external pressure on the thorax (mm Hg) (internal abdominal sensor) * ** * : p  0,02 ** : p  0,01

Results t-values external pressure on the thorax (mm Hg) (internal thoracic sensor) * : p  0,02 ** : p  0,01 ** *

Results t-values external pressure on the abdomen (mm Hg) (internal abdominal sensor) ** : p  0,01 **

Results t-values external pressure on the abdomen (mm Hg) (internal thoracic sensor) ** : p  0,01 **

Results An intracavitary pressure change was seen with: 8.18 kg (SD: 3.7) on the abdomen 9.05 kg (SD: 4) on the thorax

Limitations of the study Sitting position >< supine position (the oesophagus is a passive structure) Negative pressure measures by applying the leaden weights > reflex contraction of the diaphragm < EMG and/or respitrace Control of the apnea by a pneumotachograph

Conclusion 1.An indirect non-invasive intracavitary pressure method was used that was able to measure pressure in two different cavities simultaneously 2.The results support previous studies that state that pressure changes in one cavity influences another cavity. 3.We have a value of an external gradual pressure  IAP/ITP

Take home message... Further studies are needed to investigate :  the influence of manual pressure on body cavities;  possible physiological reactions with :  sustained >< transient elevated IAP/ITP  factor time (acute >< chronic)  and there is still the question of etiology Considering a tertiary cause of elevated IAP/ITP : the musculoskeletal system

Acknowledgements Academic Hospital of Antwerp, Belgium (UZA) Commission for Osteopathic Research, Practice and Promotion (CORPP vzw)

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