Effect of body position on oesophageal and gastric pressures in the anaesthetised dog

Abstract

The effect of body position on lower oesophageal sphincter pressure (LOSP), gastric pressure and barrier pressure (BrP) was investigated in 40 dogs anaesthetised for neutering procedures. The dogs were placed in lateral recumbency followed by dorsal recumbency (group 1) or vice versa (group 2). LOSP decreased significantly in the animals which were positioned initially in lateral recumbency, when they were then placed in dorsal recumbency, while those initially positioned in dorsal recumbency showed no significant change in their LOSP or BrP when their position was altered to lateral recumbency. When the data from both groups were pooled, LOSP and BrP were significantly lower when the dogs were in dorsal compared to lateral recumbency (P < 0.05).

Effect of endogenous progesterone and oestradiol-17β on the incidence of gastro-oesophageal reflux and on the barrier pressure during general anaesthesia in the female dog

“…Consequently, the results are not directly comparable. Nevertheless, in general, the mean BrPs recorded in the present study were similar to the respective BrP reported by Waterman & Hashim (1992), and comparable with the respective values reported by Waterman et al. (1995).…”

“…In dogs under general anaesthesia, shortly after induction and before commencement of surgery, the following values of BrP have been reported in three relevant studies: 5.0 ± 2.4 mmHg (Hashim et al. 1995), 8.5 ± 3.4 mmHg with the animals in dorsal recumbency and 7.6 ± 3.1 mmHg with the animals in dorsal recumbency after being positioned in right lateral recumbency for a period of 5 minutes (Waterman et al. 1995), and approximately 11 mmHg with the animals in left lateral recumbency (Waterman & Hashim 1992) (values from the three studies presented here were selected based on the criterion of resembling, as closely as possible, the protocol of the present study).…”

“…2001). The catheter was orientated so that the transducer was positioned to face dorsally (towards the spine) and this orientation was carefully maintained during the withdrawal (Waterman et al. 1995), to avoid variation because of radial asymmetry in sphincteric pressure (Van der Hoeven et al.…”

Gastro‐Oesophageal Reflux during Thiopentone or Propofol Anaesthesia in the Cat

“…LOSP and BrP seem to be very low in anaesthetized cats (Hashim and Waterman, 1991, 1993) when compared with dogs (Waterman and Hashim, 1992; Hashim et al., 1995; Waterman et al., 1995) and humans (Hunt et al., 1984) and the risk of GOR appears to be very high in these animals, with an expected incidence of 75 % (Hashim and Waterman, 1993), if human criteria are applied. A plausible explanation for our inability to record such a high incidence of GOR in the cat and a significant difference in the incidence of GOR between the two groups of the present study may lie in the possibility that the threshold LOSP or BrP below which GOR occurs in the cat is even lower than 10 mmHg.…”

Συμβολή Στη Μελέτη Της Επίδρασης Της Προγεστερόνης Και Της Οιστραδιόλης - 17β Στη Λειτουργικότητα Του Οπισθίου Οισοφαγικού Σφιγκτήρα Και Στην Εκδήλωση Γαστροοισοφαγικής Παλινδρόμησης Κατά Τη Διάρκεια Της Γενικής Αναισθησίας Στο Σκύλο

“…Έτσι, θεωρητικά, ΓΟΠ θα μπορούσε να προκληθεί ακόμα και όταν η πίεση του ΚΟΣ είναι φυσιολογική, εφόσον αυξηθεί η ενδογαστρική πίεση. Ωστόσο, έχει αποδειχθεί ότι σε υγιείς ανθρώπους παρατηρείται αντανακλαστική αύξηση της πίεσης του ΚΟΣ, ως ανταπόκριση στην αύξηση της ενδοκοιλιακής πίεσης, με αποτέλεσμα να αποτρέπεται η ΓΟΠ (Cohen & Harris 1971, Cotton & Smith 1984, Hardy 1988, ενώ το ίδιο φαίνεται να συμβαίνει και στον σκύλο (Ali Khan et al 1974, Franzi et al 1990, Hashim et al 1995, Stakeberg & Lehmann 1999. Βεβαίως, ΓΟΠ μπορεί να συμβεί και στην περίπτωση που η πίεση του ΚΟΣ μειωθεί τόσο ώστε να εξομοιωθεί με την ενδογαστρική, δηλαδή αν η πίεση φραγμού μηδενιστεί.…”