Validation of ACB in vitro and in vivo as a biomagnetic method for measuring stomach contraction

Background The aim of this study was to validate a biomagnetic method (alternate current biosusceptometry, ACB) for monitoring gastric wall contractions in rats. Methods In vitro data were obtained to establish the relationship between ACB and the strain‐gauge (SG) signal amplitude. In vivo experiments were performed in pentobarbital‐anesthetized rats with SG and magnetic markers previously implanted under the gastric serosa or after ingestion of magnetic material. Gastric motility was quantified from the tracing amplitudes and frequency profiles obtained by Fast Fourier Transform. Key Results The correlation between in vitro signal amplitudes was strong (R = 0.989). The temporal cross‐correlation coefficient between the ACB and SG signal amplitude was higher (P < 0.0001) in the postprandial (88.3 ± 9.1 V) than in the fasting state (31.0 ± 16.9 V). Irregular signal profiles, low contraction amplitudes, and smaller signal‐to‐noise ratios explained the poor correlation between techniques for fasting‐state recordings. When a magnetic material was ingested, there was also strong correlation in the frequency and signal amplitude and a small phase‐difference between the techniques. The contraction frequencies using ACB were 0.068 ± 0.007 Hz (postprandial) and 0.058 ± 0.007 Hz (fasting) (P < 0.002) and those using SG were 0.066 ± 0.006 Hz (postprandial) and 0.059 ± 0.008 Hz (fasting) (P < 0.005). Conclusions & Inferences In summary, ACB is reliable for monitoring gastric wall contractions using both implanted and ingested magnetic materials, and may serve as an accurate and sensitive technique for gastrointestinal motility studies.     

Role of anorectal manometry in children with severe constipation

Objective Constipation is one of the most frequent disorders of the digestive tract in children and it can be an important problem in paediatric and surgical practice. Most of the time, the cause is psychological or because of a slowing of colonic transit, but it can be a sign of organic gastrointestinal outlet obstruction. Some patients with chronic constipation are resistant to a medical approach and they present with a severe form of constipation that needs recurrent hospital admission. Anorectal manometry (ARM) is a noninvasive procedure and it helps to explain the mechanisms of defecation disorders. The aim of the present study was to evaluate the role of ARM in children with severe constipation. Method From October 2003 to October 2006, in the Paediatric Surgery Unit, 85 children – aged more than 1 year – with severe constipation were seen. The mean age was 5 years (range, 1–13). At presentation, every child had abdominal and rectal examination in order to identify abdominal distension or faecal masses. Bowel preparation with enemas was performed before ARM in patient with a rectal faecaloma. Myoelectric activity of the internal anal sphincter and resting anal tone was recorded; recto‐anal inhibitory reflex (RAIR) was tested to exclude Hirschsprung’s disease (HD). Anal tone was considered normal until 50 cm H₂O. When the RAIR was absent, the patient underwent rectal suction biopsies (RSB) for histology and acetylcholinesterase histochemistry. In cases of normal or high anal tone with the RAIR present, the child had bowel cleaning, medical treatment, 2‐ and 6‐month follow‐up. Children with ineffective treatment at follow‐up underwent RSB. In case of HD, a laparoscopic‐assisted endorectal pull‐through (ERPT) according to Georgeson’s technique was performed. Results Seventy per cent of the patients had bowel preparation before ARM. In four patients the ARM was impossible to assess because of crying. In 28 patients, the anal tone result was higher than 50 cm H₂O and local treatment with anaesthetic agents was used for 8 weeks. Seventeen patients underwent RSB: 11 patients with RAIR absent/unclear, 4 noncooperative children and 2 patients with ineffective medical treatment at follow‐up. HD was diagnosed in 2 patients and laparoscopic‐assisted ERPT was performed. The remaining patients had good results at 6‐month follow‐up. Conclusion ARM is a noninvasive diagnostic tool to study the mechanism of defecation in children with constipation in order to prescribe the appropriate treatment. This procedure can be used in every child – aged more than 1 year – with severe constipation and assessment of the RAIR can select the cases for RSB.     

Perioperative management of the older patient

With an ageing population, anaesthetists have increasing importance in taking care of the elderly undergoing surgery. Physiological changes, comorbidities, frailty and cognitive dysfunction conduce to adverse outcomes, institutionalization and mortality. This article looks into the physiological changes and anaesthetic considerations in the older patients. Preoperative assessment including use of the Comprehensive Geriatric Assessment, frailty, nutritional and cognitive assessments will be discussed. Prehabilitation can potentially modify frailty, improve outcome and reduce length of hospitalization. Preoperative nutritional therapy, where indicated, can improve nutritional status and reduce complications.Two important complications to avoid in the elderly are perioperative neurocognitive disorder (PND) and postoperative acute kidney injury (PO-AKI). PND is a predictor of poor outcome including mortality. Intraoperative electroencephalogram monitoring may help to decrease the incidence of delirium. PO-AKI is a common morbidity in elderly and its incidence can be reduced by appropriate fluid therapy and drug choice.     

Initial experience on efficacy in closure of cryptoglandular and Crohn’s transsphincteric fistulas by the use of the anal fistula plug

Background and aims

It was the aim of this prospective study to analyze the efficacy of the Cook Surgisis® AFP? anal fistula plug (AFP) for the closure of cryptoglandular and Crohn’s disease-associated transsphincteric anorectal fistulas.

Materials and methods

All patients with transsphincteric anorectal fistulas who underwent a surgical procedure using the AFP were prospectively enrolled in this study. Inclusion criteria included transsphincteric, single-tract fistulas. Patients’ demographics, fistula etiology, surgical variables, continence (Cleveland Clinic Florida incontinence score), quality of life (fecal incontinence quality of life), and success rates were prospectively recorded. Surgery was performed in a standardized technique including irrigation of the fistula tract, placement, and internal fixation of the Cook Surgisis® AFP? anal fistula plug. No flap or excision of the fistula tract was performed. Success was defined as closure of both internal and external openings, absence of drainage without further intervention, and absence of abscess formation. Follow-up information was derived from clinical examination 3, 6, 9, and 12 months postoperatively.

Results

Within 6 months (August 2006 to January 2007), a total of 19 AFPs were inserted in 19 patients (8 females, 11 males; mean age, 38 years). Out of 19 patients, 12 had cryptoglandular and 7 had Crohn’s associated transsphincteric fistulas. Three patients were smokers, one patient had methicillin-resistant Staphylococcus aureus infection. Mean operative time was 15 min (range, 8–22); no morbidity occurred. After a mean follow-up of 279 days (SD?=?68.0) and one patient lost to follow-up, the overall success rate was 61% (12 of 18) at 9 months postoperatively. Focusing solely on cryptoglandular fistulas, the success rate was 45.5% (5 of 11), whereas it was 85.7% (6 of 7) in transsphincteric fistulas associated with Crohn’s disease. Five patients with failure of AFP (plug dislodgement, n?=?2; persistent secretion, n?=?3) had reoperation (27.8%). The reasons for failure were infection requiring drainage (n?=?2) and persistent drainage (n?=?3). No deterioration of continence was documented.

Conclusion

The success rate for the Cook Surgisis® AFP? anal fistula plug for the closure of complex anorectal fistulas both in cryptoglandular and Crohn’s associated fistulas was 45.5 and 85.7%, respectively. Further analysis is needed to explain the definite role of this innovative technique in comparison to traditional surgical techniques.     

Effects of the correction of renal anaemia by erythropoietin on physiological changes during exercise

Abstract. The effects of treating the anaemia of end-stage renal failure with erythropoietin were studied in nine dialysis patients. The increase in haemoglobin concentration (by 59% from 7.0 ± 1.2 to 11.1 ± 1.1 g dl^-1) was associated with increases in exercise duration (by 41%) and maximum oxygen consumption (by 34%). Treatment reduced resting heart rate but did not significantly alter heart rate at maximum exercise, nor resting or exercise blood pressure. Resting arterial potassium concentrations were slightly increased after treatment, but they increased similarly in relation to minute ventilation during exercise. Lactic acidaemia developed during exercise at both levels of haemoglobin, and was accompanied by similar reductions in arterial pH and bicarbonate levels but constant Pao₂ and Paco₂. Ventilation was coupled to the metabolic rate of carbon dioxide production, ventilatory dead-space and arterial Pco₂ before and after treatment of anaemia, the ventilatory requirement for carbon dioxide elimination being unchanged. Treatment of anaemia did not alter resting arterial lactate concentration; the concentration of lactate at maximum exercise was increased slightly following treatment but this increase did not reach statistical significance. The rate of increase in arterial lactate concentration as a function of oxygen consumption, assessed both with respect to the 'lactate threshold' and 'lactate slope index', was significantly delayed by treatment. Treatment of anaemia also delayed the 'anaerobic threshold', and there was good correlation between lactate and anaerobic thresholds. Treatment of renal anaemia by erythropoietin thus results in improved tissue oxygen supply during exercise, reflected by delay in the onset of lactic acidaemia.     

An analysis of research and clinical practice in neonatal pain management

PURPOSE: To review the literature on neonatal pain management with a focus on historical misconceptions, ethical issues, barriers to practice, the role of the advanced practice nurse (APN), and suggested improvements. DATA SOURCES: Selected research and review articles in nursing and medical literature. CONCLUSIONS: Health care professionals agree that neonates experience pain and in turn deserve effective treatment. Research is controversial regarding the extent of pain management necessary in relation to short-term benefits and long-term consequences. Ethical issues arise when research supporting pain management is not consistently utilized in nursing practice. IMPLICATIONS FOR PRACTICE: Protocols and standardized pain management strategies have demonstrated a beneficial effect on overall patient outcomes. The APN is identified as being in the optimal position to facilitate enhanced neonatal pain management through research, education, and direct clinical care.