Biomedical subjects

David Z Lubowski

Publications and source records attributed to David Z Lubowski.

4 recordsLinked to original sources

PubMed2006

Anal manometry: a comparison of techniques.

PURPOSE: Methods of anal manometry vary between centers, resulting in potential difficulties in interpretation of results. This study compared several accepted manometric techniques in healthy control subjects and in patients with fecal incontinence. METHODS: Eleven patients with fecal incontinence (M:F = 3:8; mean age = 67 years) and ten healthy control subjects (M:F = 3:7; mean age = 64 years) underwent anal manometry using five different methods: 1) water-perfused side hole; 2) water-perfused end hole; 3) microtransducer; 4) microballoon; 5) portable Peritron. Using a station pull-through technique, anal pressures (resting, squeeze, and cough pressures) were recorded at 1-cm intervals from rectum to anal verge, as well as radial pressures in four quadrants for Methods 1 and 2. RESULTS: Water perfusion side hole recorded slightly higher maximal resting pressures; however, there were no significant differences between any of the methods. In healthy control subjects, distal maximal squeeze pressures were significantly higher (P < 0.05) than proximally as measured by microtransducer. There were slight (nonsignificant) variations in radial pressures with water perfusion and microtransducer. Peritron values for maximum resting pressure and maximum squeeze pressure were lower than those recorded by water perfusion side hole by a factor of 0.8. CONCLUSIONS: There is no significant variation in anal pressure recordings using standard manometry techniques. Variations in radial pressures are slight and not significant in clinical studies. Results obtained with portable nonperfusion systems must be interpreted appropriately.

Aged↗

PubMed2006

Obstetric-induced incontinence: a black hole of preventable morbidity.

There is a detailed literature comprising clinical and anorectal physiological studies linking faecal incontinence to vaginal delivery. Specific risk factors are high infant birthweight, forceps delivery and prolonged second stage of labour. The onset of symptoms may be delayed for many years. Faecal incontinence occurs in more than 10% of adult females and urinary incontinence in about a third of multiparous women. This places a very large economic burden on the Australian health system. A conservative estimate for overall management of incontinence would be in excess of $A700 million but the actual amount is unknown. Preventative measures for avoiding pelvic floor injuries need to be established, and safe obstetric practice needs to be redefined in the light of current knowledge about incontinence. Outcome measures for safe birthing should not only include infant and maternal mortality and infant morbidity, but should also include the long-term effects of vaginal delivery on the pelvic floor, particularly urinary and faecal incontinence. Several state reports and one federal senate report on safe birthing have been lacking in this area. The safety of birthing centres and home birthing needs to be examined to provide birthing mothers with complete and appropriate information about safety in order that they may consider their options. Appropriate Caesarean section rates for optimal birthing safety are unknown and need to be re-examined. Calls for overall reduction in Caesarean section rates in Australia are inappropriate and cannot be justified until the effects of pelvic floor injury are added to the overall assessment.

Australia↗

PubMed2005

Impaired proximal colonic motor response to rectal mechanical and chemical stimulation in obstructed defecation.

PURPOSE: Both motor and sensory dysfunction have been implicated in the pathogenesis of obstructed defecation. We have found that despite preservation of a defecatory urge, patients with obstructed defecation have lost the normal predefecatory augmentation in frequency and amplitude of colonic propagating pressure waves. This observation might be explainable by either altered rectal sensory thresholds or by dysfunction in the colonic motor apparatus. By measuring rectal sensory thresholds and proximal colonic motor responses to rectal mechanical and chemical stimuli, we tested the hypotheses that central perception of rectal stimuli is enhanced and that the proximal colonic motor response to rectal stimulation is attenuated. METHODS: In seven patients with obstructed defecation and ten healthy volunteers we measured proximal colonic motor responses and sensory thresholds in response to both rectal balloon distention and rectal instillation of chenodeoxycholic acid. RESULTS: In controls, but not in patients, rectal mechanical distention significantly reduced and chemical stimulation significantly increased the frequency of proximal colonic propagating sequences (P = 0.01). There was no significant difference in rectal sensory thresholds between patients and controls. Prior instillation of chenodeoxycholic acid significantly reduced (P < 0.03) maximum tolerated balloon volume and defecatory urge volume to comparable degree in both patients and controls. CONCLUSIONS: In obstructed defecation, 1) the normal rectocolonic pathways mediating stimulation-induced proximal colonic propagating pressure waves are nonfunctioning, and. 2) central perception of these rectal stimuli is normal.

Adult↗

PubMed2004

Abnormal predefecatory colonic motor patterns define constipation in obstructed defecation.

BACKGROUND & AIMS: The pathophysiology of constipation in the syndrome of obstructed defecation is unknown. Using 24-hour pancolonic manometric recordings of the unprepared colon to record basal pressures and spontaneous defecation episodes, we tested the hypothesis that the frequency, timing, or spatial distribution of propagating colonic pressure waves is abnormal in patients with obstructed defecation. METHODS: In 11 patients with obstructed defecation and 16 healthy controls, pressures were recorded using a nasocolonic catheter that was positioned such that 16 recording sites spanned the unprepared colon at 7.5-cm intervals. RESULTS: The overall frequency of propagating sequences (PS) in the colon did not differ between patients and controls. When compared with controls, patients had a significant increase in the frequency of retrograde and antegrade PS (P < 0.05) in the left colon and a significant reduction in the amplitude of propagating pressure waves throughout the entire colon (P < 0.03). Defecation occurred in 6 of 11 patients and 9 of 16 controls. In the 15 minutes before defecation, controls showed a highly significant increase in frequency (P = 0.001) and amplitude (P = 0.01) of PS. In contrast, patients did not demonstrate this or the typical spatiotemporal organization of PS normally observed before expulsion of stool. CONCLUSIONS: Patients with obstructed defecation lack the normal predefecatory augmentation in frequency and amplitude of propagating pressure waves and lack the normal stereotypic spatiotemporal patterning of colonic pressure waves that would normally culminate in effective expulsion of stool.

Adult↗