Gastric emptying of water in children with severe functional fecal retention.

The objective of this study was to evaluate gastric emptying (GE) in pediatric patients with functional constipation. GE delay has been reported in adults with functional constipation. Gastric emptying studies were performed in 22 children with chronic constipation, fecal retention and fecal incontinence, while presenting fecal retention and after resuming regular bowel movements. Patients (18 boys, median age: 10 years; range: 7.2 to 12.7 years) were evaluated in a tertiary pediatric gastroenterology clinic. Gastric half-emptying time of water (reference range: 12 ± 3 min) was measured using a radionuclide technique immediately after first patient evaluation, when they presented fecal impaction (GE1), and when they achieved regular bowel movements (GE2), 12 ± 5 weeks after GE1. At study admission, 21 patients had reported dyspeptic symptoms, which were completely relieved after resuming regular bowel movements. Medians (and interquartile ranges) for GE1 and GE2 were not significantly different [27.0 (16) and 27.5 (21) min, respectively (P = 0.10)]. Delayed GE seems to be a common feature among children with chronic constipation and fecal retention. Resuming satisfactory bowel function and improvement in dyspeptic symptoms did not result in normalization of GE data.

Gastric emptying of water in children with severe functional fecal retention

The objective of this study was to evaluate gastric emptying (GE) in pediatric patients with functional constipation. GE delay has been reported in adults with functional constipation. Gastric emptying studies were performed in 22 children with chronic constipation, fecal retention and fecal incontinence, while presenting fecal retention and after resuming regular bowel movements. Patients (18 boys, median age: 10 years; range: 7.2 to 12.7 years) were evaluated in a tertiary pediatric gastroenterology clinic. Gastric half-emptying time of water (reference range: 12 ± 3 min) was measured using a radionuclide technique immediately after first patient evaluation, when they presented fecal impaction (GE1), and when they achieved regular bowel movements (GE2), 12 ± 5 weeks after GE1. At study admission, 21 patients had reported dyspeptic symptoms, which were completely relieved after resuming regular bowel movements. Medians (and interquartile ranges) for GE1 and GE2 were not significantly different [27.0 (16) and 27.5 (21) min, respectively (P = 0.10)]. Delayed GE seems to be a common feature among children with chronic constipation and fecal retention. Resuming satisfactory bowel function and improvement in dyspeptic symptoms did not result in normalization of GE data.

A functional study of caustic strictures of the esophagus in children.

The objective of the present study was to assess esophageal motor function in 21 children (7.5 +/- 2.9 years) with caustic strictures. Esophageal manometry was performed using a water-infusion system interfaced with a polygraph and displayed on a computer screen. The data were compared with those obtained from 9 healthy children. Radionuclide transit was determined by studying deglutition of a single bolus of 99mTc pertechnetate in 10 ml of water. Non-peristaltic low-amplitude and long-duration waves were the most common findings detected in patients with strictures longer than 20% of esophageal length (N = 11). Compared with the control group, these patients presented lower mean amplitude and longer mean duration of waves (24.4 +/- 11.2 vs 97.9 +/- 23.7 mmHg, P < 0.05, and 6.7 +/- 2.4 vs 1.6 +/- 0.1 s, P < 0.05, respectively). Six patients presented low-amplitude waves just below the constricted site. Ten children presented delayed esophageal transit. There was an association between dysphagia and abnormalities on manometry (P = 0.02) and between symptoms and scintigraphy data (P = 0.01). Dysphagia in caustic strictures is due to esophageal motility abnormalities, which are closely related to the scarred segment.

A functional study of caustic strictures of the esophagus in children

The objective of the present study was to assess esophageal motor function in 21 children (7.5 ± 2.9 years) with caustic strictures. Esophageal manometry was performed using a water-infusion system interfaced with a polygraph and displayed on a computer screen. The data were compared with those obtained from 9 healthy children. Radionuclide transit was determined by studying deglutition of a single bolus of 99mTc pertechnetate in 10 ml of water. Non-peristaltic low-amplitude and long-duration waves were the most common findings detected in patients with strictures longer than 20 percent of esophageal length (N = 11). Compared with the control group, these patients presented lower mean amplitude and longer mean duration of waves (24.4 ± 11.2 vs 97.9 ± 23.7 mmHg, P < 0.05, and 6.7 ± 2.4 vs 1.6 ± 0.1 s, P < 0.05, respectively). Six patients presented low-amplitude waves just below the constricted site. Ten children presented delayed esophageal transit. There was an association between dysphagia and abnormalities on manometry (P = 0.02) and between symptoms and scintigraphy data (P = 0.01). Dysphagia in caustic strictures is due to esophageal motility abnormalities, which are closely related to the scarred segment.

The role of videolaparoscopy in the diagnostic and therapeutic approach of nonpalpable testis

OBJECTIVE: Evaluate the results from the first 5 years of experience with laparoscopy for diagnosis and treatment of nonpalpable testes. MATERIALS AND METHODS: Medical records of 51 patients submitted to laparoscopic testicular exploration, during a 5-year period, were retrospectively analyzed. Patients' mean age was 65.7 months (median = 48) on the first procedure. The youngest patient was 10 months and the oldest was 14 years old on the first surgery. Twenty-four (47 percent) patients presented nonpalpable testes bilaterally, 7 (14 percent) only at the right side and 20 (39 percent) at the left, totaling 75 testicular units assessed. Patients who had their testes palpated after anesthetic induction were excluded from the study, and in all other cases, surgical management was based on the testicular position and viability. During the post-operative follow-up, surgical success was classified as palpable testis in scrotal sac, with adequate consistency and volume. RESULTS: Nine (12 percent) testes were not localized, but their vessels and deferent duct were atrophic. Two (3 percent) testes were intra-abdominal and atrophic, and 2 (3 percent) gonads, in the same patient, had a dysmorphic aspect. Nineteen (25 percent) testicular units were located close to the internal inguinal ring (peeping testes) and, in 22 (29 percent) units, the spermatic vessels and deferent duct penetrated the internal inguinal ring. Eight (10 percent) testes were located at a distance of less than 2 cm from the internal inguinal ring and 13 (17 percent) at a distance greater than 2 cm. The 2 intra-abdominal atrophic testes were removed. Inguinotomy was performed in a total of 41 (54 percent) cases, reaching a surgical success of 89 percent. Laparoscopic orchiopexy in one stage, without vascular ligation, was performed in 9 (12 percent) testes, which presented a distance of less than 2 cm from the internal inguinal ring, also with a surgical success index of 89 percent. Orchiopexy in 2 stages, with ligation of the spermatic vessels, was performed in 13 (17 percent) testicular units located at a distance greater than 2 cm from the internal inguinal ring, reaching 77 percent of good results. CONCLUSION: Videolaparoscopy is a safe and effective method for diagnosis and treatment of nonpalpable testis.

The role of videolaparoscopy in the diagnostic and therapeutic approach of nonpalpable testis.

OBJECTIVE: Evaluate the results from the first 5 years of experience with laparoscopy for diagnosis and treatment of nonpalpable testes. MATERIALS AND METHODS: Medical records of 51 patients submitted to laparoscopic testicular exploration, during a 5-year period, were retrospectively analyzed. Patients' mean age was 65.7 months (median = 48) on the first procedure. The youngest patient was 10 months and the oldest was 14 years old on the first surgery. Twenty-four (47%) patients presented nonpalpable testes bilaterally, 7 (14%) only at the right side and 20 (39%) at the left, totaling 75 testicular units assessed. Patients who had their testes palpated after anesthetic induction were excluded from the study, and in all other cases, surgical management was based on the testicular position and viability. During the post-operative follow-up, surgical success was classified as palpable testis in scrotal sac, with adequate consistency and volume. RESULTS: Nine (12%) testes were not localized, but their vessels and deferent duct were atrophic. Two (3%) testes were intra-abdominal and atrophic, and 2 (3%) gonads, in the same patient, had a dysmorphic aspect. Nineteen (25%) testicular units were located close to the internal inguinal ring (peeping testes) and, in 22 (29%) units, the spermatic vessels and deferent duct penetrated the internal inguinal ring. Eight (10%) testes were located at a distance of less than 2 cm from the internal inguinal ring and 13 (17%) at a distance greater than 2 cm. The 2 intra-abdominal atrophic testes were removed. Inguinotomy was performed in a total of 41 (54%) cases, reaching a surgical success of 89%. Laparoscopic orchiopexy in one stage, without vascular ligation, was performed in 9 (12%) testes, which presented a distance of less than 2 cm from the internal inguinal ring, also with a surgical success index of 89%. Orchiopexy in 2 stages, with ligation of the spermatic vessels, was performed in 13 (17%) testicular units located at a distance greater than 2 cm from the internal inguinal ring, reaching 77% of good results. CONCLUSION: Videolaparoscopy is a safe and effective method for diagnosis and treatment of nonpalpable testis.

Extended hiatoplasty: early experience with a simple technique to increase the intraabdominal esophageal length in complicated gastroesophageal reflux.

PURPOSE: The aim of this paper is to describe the experience of the Division of Pediatric Surgery of State University of Campinas Medical School with a simple technique of extended hiatoplasty to achieve intraabdominal placement of the distal esophagus in difficult situations. METHODS: From April 1997 to November 1999, 7 patients who had either complicated or recurrent gastroesophageal reflux (GER) underwent open (2 patients) or laparoscopic (5 patients) correction of GER that included an extended hiatoplasty. All had undergone previous unsuccessful clinical or surgical treatment. To investigate the severity of the disease, diagnostic endoscopy or barium swallow were performed before surgery. Postoperatively, these children underwent clinical evaluation or any additional diagnostic procedure deemed necessary. RESULTS: Using the extended hiatoplasty, a good length of intraabdominal esophagus could be achieved in every patient. No complications resulted from the procedure itself. There was a late instance of paraesophageal hernia with recurrence of GER attributable to disruption of the hiatoplasty, which was rerepaired through a laparoscopic approach. Symptomatic improvement was observed in all but the patient with caustic stricture. CONCLUSIONS: Extended hiatoplasty is a simple maneuver that may represent a good option to increase the length of intraabdominal esophagus in patients with a short esophagus secondary to severe GER disease, being associated with a high success rate and low morbidity. J Pediatr Surg 36:555-558.

Morphometry and histology of gonads from 13 children with dysgenetic male pseudohermaphroditism.

BACKGROUND: Dysgenetic male pseudohermaphroditism (DMP) is a sexual differentiation disorder characterized by bilateral dysgenetic testes, persistent müllerian structures, and cryptorchidism in individuals with a 46,XY karyotype. However, the histologic criteria for the diagnosis of DMP are poorly established. OBJECTIVE: To determine gonadal histology in children with DMP. PATIENTS AND METHODS: Between 1996 and 1998, 13 patients with DMP were evaluated on our service. The clinical diagnosis of DMP was based on a 46,XY karyotype, sex ambiguity, high levels of follicle-stimulating hormone and low levels of antimüllerian hormone, a decreased testosterone response to human chorionic gonadotropin stimulation without accumulation of testosterone precursors, and the presence of müllerian structures. Molecular sequencing the HMGbox region of the SRY gene did not reveal any mutations. Biopsies were performed for 22 of 26 gonads (patient age at the time of biopsy, 16 months to 10 years). Conventional microscopy was used to evaluate mean tubular diameter, tubular fertility index, and number of Sertoli cells per tubular profile. RESULTS: All 26 gonads were located outside of the labioscrotal folds. Their histologic features varied from only a reduction in tubular size to features of a streak gonad. Five of the 22 gonads grossly resembled a streak gonad. The mean tubular diameter was severely reduced (>30% reduction relative to the normal tubular diameter for the patient's age) in 4 gonads, markedly reduced (10%-30%) in 11 gonads, slightly reduced (<10%) in one gonad, and normal in one gonad. The tubular fertililty index, expressed as the percentage of tubular profiles containing germ cells, was severely reduced (<30% of normal values) in 9 gonads, markedly reduced (50%-30%) in 2 gonads, and normal in 6 gonads. The number of Sertoli cells per tubular profile was elevated in 16 gonads and normal in one gonad. Thin tubules surrounded by fibrous tissue were occasionally observed. CONCLUSION: The histologic findings confirmed the clinical diagnosis of DMP in every patient in the present series. However, gonadal histology was variable, and careful morphometric evaluation may be necessary to establish the diagnosis.

Lateral esophagostomy: an alternative in the initial management of long gap esophageal atresia without fistula.

The authors report an alternative method of cervical esophagostomy that was used in a child with type A esophageal atresia. This method involved performing a lateral esophagostomy in the proximal pouch, preserving its distal end, allowing the child to swallow normally, without choking, while stimulating the spontaneous growth of the proximal esophagus. As a result, the infant could be discharged home on G-tube feedings while waiting for spontaneous growth of the proximal pouch to occur. There were no episodes of aspiration during this period, and definitive reconstruction through end-to-end esophageal anastomosis was accomplished successfully at the age of 18 months. The authors consider that this alternative might increase the possibility of a definitive correction through delayed primary anastomosis of the infant's own esophagus in children with this type of malformation.

Selective surgical indication in the management of neutropenic children presenting with acute abdomen.

As the treatment of pediatric malignancies improves and survival increases, the diagnosis of acute abdomen in these patients also becomes more common. Nevertheless, the management of this condition is still controversial. The authors report their experience in treating 12 neutropenic children with acute abdomen. The charts of 12 neutropenic patients with a diagnosis of acute abdomen treated at Boldrini Children's Cancer Center in Campinas, Brazil, between 1991 and 1996, were reviewed. Therapeutic strategy included an initial period of bowel rest, general supportive measures, and broad-spectrum antibiotics while waiting for the neutrophil count to rise. Three patients recovered completely without surgery, 8 underwent late surgery without complications, and 1 died due to uncontrolled sepsis before surgery. The treatment of acute abdomen in neutropenic children remains controversial. As shown in the present series, an initial nonoperative approach with selective surgical indication appears to be safe and to yield good results. Supportive treatment, until the neutrophil count rises, followed by surgery, if necessary, appears to be a sound therapeutic approach for neutropenic children with acute abdomen.

Beckwith-Wiedemann syndrome and virilizing cortical adrenal tumor in a child.

The authors report a case of a virilizing adrenal tumor that developed in a 2-year-old child with Beckwith-Wiedemann syndrome (BWS). He had a fetal diagnosis of omphalocele and a history of neonatal adrenal cysts. The importance of prenatal diagnosis of BWS and postnatal follow-up of tumors is discussed. The differential diagnosis of adrenal pathologies occurring in BWS also is reviewed.

Pyloroplasty improves long-term gastric emptying in rats undergoing fundoplication.

BACKGROUND: Conflicting reports exist regarding the permanence of improved gastric emptying (GE) after fundoplication for gastroesophageal reflux in children. METHODS: Changes in gastric volume (GV) and GE of a radiolabeled mixed meal induced by a Nissen fundoplication (NF) were compared with those with a NF plus pyloroplasty (NF + P). GE was measured preoperatively, 15 and 30 days postoperation, in 24 Sprague-Dawley rats; 12 had NF alone, and 12 had NF + P Results were expressed as percent gastric retention at 90 minutes (GR90). GV was measured at the same time periods in 20 additional rats. RESULTS: NF rats had enhanced GE with reduction of preoperative GR90 from 37.6% to 23.7% at 15 days (P < .05); however, at 30 days the GR90 increased to 34.3%. NF + P rats had enhanced GE with reduction in GR90 from 37.2% to 20.8% at 15 days (P< .05), which persisted at 30 days (20.4%). Mean GV decreased from (1.36 mL/100 g body weight) preoperation to 0.86 at 15 days (P< .05) at 15 days in the NF group, and returned to 1.29 at 30 days. Mean GV decreased from 1.36 to 0.91 at 15 days in the NF + P rats and persisted at 0.90 at 30 days. CONCLUSION: In the rat model, NF enhances GE transiently, whereas NF + P produces long-term enhancement of GE.

Pre-operative control of arterial hypertension using ketoconazole in pediatric patients with adrenocortical tumors.

Adrenocortical tumors are rare in childhood, appearing more frequently in some regions such as South and South-eastern regions of Brazil and India. Common clinical signs include virilization, Cushing's syndrome, feminization and hypertension, either isolated or in association. The aim of this report is to present our experience with the pre-operative use of ketoconazole in children with an adrenocortical tumor to control elevated blood pressure levels non-responsive to the usual treatment. Over the last 16 years, of 46 children diagnosed as having adrenocortical tumor, 17 developed hypertension (diastolic pressure greater than the 95th percentile for age and sex according to data from the Task Force on Blood Pressure Control in Children), associated with virilization and/or Cushing's syndrome. In three of these 17 patients, conventional antihypertensive therapy failed, and they were treated with ketoconazole (200-300 mg/day). This resulted in rapid control of the blood pressure. It is concluded that in selected patients, ketoconazole may be useful adjuvant therapy for the palliative control of the arterial hypertension secondary to adrenocortical tumors, without side effects.

[Role of anorectal manometry in the differential diagnosis of chronic constipation in children] / Papel da manometria anorretal no diagnóstico diferencial da constipação em crianças.

OBJECTIVES: 1. To evaluate the role of anorectal manometry in recognizing patients with histological abnormalities of the myenteric plexus as the cause of chronic constipation. 2. To correlate clinical features with the etiology of the constipation.METHODS: The etiology of the constipation was identified retrospectively from the medical records of 57 patients submitted to anorectal manometry. The test was performed in the Pediatric Gastroenterology Laboratory of the University Hospital of the State University of Campinas Medical School. The procedure was performed using a single-balloon system in which a water-perfused pressure transducer was interfaced with a polygraph and displayed on a computer screen. Manometry was performed in patients who, after 6 to 23 months of intense medical treatment using osmotic laxatives and dietary fibres (20 g/d), continued to develop fecal impaction and/or needed evacuatory enema. Regularization of bowel movements during at least 24 months follow-up or the visualization of abnormalities in myenteric plexus in rectal biopsy were used as reference points for the definitive diagnosis.RESULTS: Rectoanal reflex was present in 44 of the 57 patients (77%). Thirteen patients with a negative reflex underwent rectal biopsy which showed abnormalities of the ganglion cells in 10. Subsequent manometry performed on those three patients revealed a normal rectoanal reflex. Sensitivity, specificity, positive and negative predictive values of the manometric test were 1.0, 0.94, 0.77 and 1.0, respectively.CONCLUSIONS: Anorectal manometry is a diagnostic technique with very small possibility of error in differential diagnosis between constipation of a chronic functional nature and that which is secondary to ganglion cell abnormalities.

[Choledochal cyst: a 10-year experience] / Cisto de colédoco: experiência de 10 anos.

BACKGROUND: Choledochal cyst is a rare abnormality usually found in infancy and childhood and mainly in females. Outcome depends on early diagnosis, complete resection of the cyst and proper hepaticoenterostomy.OBJECTIVE: The aim of this paper is to evaluate the outcome of 18 patients operated in ten years. METHODS: Retrospective chart review. RESULTS AND DISCUSSION: Age ranged between 20 days and 13 years (mean 3 years). Fifteen (83%) were female and 03 (17%) male. Signs presented included 15 (83%) with jaundice, 11 (61%) with dark urine, 10(55%) with pale colored stools, 09 (50%) with abdominal pain and palpable mass in only 02(11%). Ultrasonography identified the cyst in 14 (77%) patients. Endoscopic retrograde cholangio-pancreatography demonstrated a long common duct in three of four cases. Anatomical types were: 09 type I, 01 type II, 07 type IV and 01 type V. Except for one patient who had a type V cyst, all patients underwent cyst resection plus Roux-en-Y hepaticojejunostomy. There were two (11%) early postoperative deaths related to deterioration of liver function. Thirteen (86%) of the 15 patients available to follow-up were symptom-free without late complications at a mean period of three years, and two (14%) patients developed chronic pancreatitis.

Comparison of intratracheal pulmonary ventilation and hybrid intratracheal pulmonary ventilation with conventional mechanical ventilation in a rabbit model of acute respiratory distress syndrome by saline lavage.

OBJECTIVES: To study changes in PaCO2 and PaO2 during intratracheal pulmonary ventilation (ITPV) and hybrid intratracheal pulmonary ventilation (h-ITPV) compared with conventional mechanical ventilation (CMV) in a rabbit model of respiratory failure, and to define the technique of h-ITPV that combines conventional mechanical ventilation and ITPV. DESIGN: Prospective, interventional study. SUBJECTS: Twelve adult New Zealand White rabbits. INTERVENTIONS: Surfactant deficiency was induced by saline lavage, and rabbits were randomized to either ITPV or h-ITPV. The study consisted of four phases: phase 0, CMV after saline lavage, ventilator rate 30 breaths/min; phase I, ITPV or h-ITPV initiated at the same pressure and rate as in phase 0; phase II, ITPV or 1.0 L/min h-ITPV bias flow, with peak inspiratory pressure (PIP) decreased and ventilator rate increased to achieve the lowest tidal volume while maintaining adequate gas exchange; and phase III, animals returned to CMV. MEASUREMENTS AND MAIN RESULTS: In phase I, no difference in PaCO2 was observed between ITPV, h-ITPV, or CMV. There was a decrease in PaO2 when switching from CMV to ITPV but not to h-ITPV. In phase II, it was possible to decrease PIP (average of 37% for ITPV and 36% for h-ITPV) and tidal volume (average of 64% for ITPV and 53% for h-ITPV) without compromising gas exchange (p < .05). Oxygenation tended to improve from phase 0 to the end of phase II. In phase III, PaCO2 increased (average of 71% for ITPV and 79% for h-ITPV) and pH decreased (p < .05). Normocapnia was achieved using significantly higher PIP and tidal volume, compared with phase 0 (p < .05). CONCLUSIONS: ITPV and h-ITPV can effectively ventilate and oxygenate rabbits with surfactant-deficient lungs at tidal volumes and therefore pressures lower than required with CMV. Maximum benefit appears to occur at high ventilator rates. These findings suggest that both modes of ventilation may represent powerful new tools in the management of patients with acute respiratory failure. (Crit Care Med 2000; 28:774-781)

Effects of intraabdominally insufflated carbon dioxide and elevated intraabdominal pressure on postoperative gastrointestinal transit: an experimental study in mice.

BACKGROUND/PURPOSE: Postoperative ileus after abdominal operations is thought to be related to the degree of surgical trauma, and it has been shown that the simple act of opening the peritoneum can decrease gastrointestinal motility. Accordingly, some investigators have shown a reduction in the duration of postoperative ileus after laparoscopic procedures. It is not clear, however, if this reduction is secondary to less manipulation of the viscera or to the lack of an abdominal incision. The aim of this study was to determine the effect of intraabdominal insufflation with CO2 on postoperative gastrointestinal transit. METHODS: Twenty-eight male mice weighing between 25 and 30 g were divided randomly into 4 groups: Control (unoperated), Incision (conventional laparotomy), Cecal (laparotomy plus cecal manipulation), and Insufflation (abdominal insufflation with CO2). Postoperative gastrointestinal motility was assessed by weighing total fecal output over the first 15 postoperative hours. RESULTS: Fecal pellet output over 15 hours in the untreated control group was 1.20 +/- 0.12 g. In mice subjected to peritoneal incision alone, fecal pellet output was significantly decreased to 0.82 +/- 0.11 g (P < .05). However, in mice subjected to abdominal insufflation with CO2, fecal pellet output was not significantly different from untreated controls (1.2 +/- 0.05 g; not significant). Fecal pellet output was markedly reduced by incision combined with cecal manipulation (0.24 +/- 0.02 g, P < .01). CONCLUSIONS: The current study findings show that abdominal insufflation, in a procedure similar to that used during laparoscopic surgery, had no measurable effect on gastrointestinal transit in awake mice. This suggests that the lack of an abdominal incision can contribute to a reduced postoperative ileus after abdominal surgery.

Interposition of a jejunal segment between esophagus and pylorus for treatment of multirecurrent gastroesophageal reflux.

Here the authors report the clinical experience with placement of an isolated jejunal segment between the esophagus and pylorus for treatment of multirecurrent gastroesophageal reflux (GER) in a child. A 6-year-old neurologically normal girl experienced severe symptomatic GER after 3 previous well-constructed Nissen fundoplications that failed over a 4-year period. The gastric cardia was closed, and a 16-cm isolated segment of proximal jejunum was placed in an isoperistaltic direction between the distal esophagus and an incision through the pylorus, extending onto both the antrum and duodenum. A gastrostomy was used for 3 months. The patient recovered from the operation without complications and has been completely relieved of reflux symptoms during the 15 months postoperation. She has gained over 6.5 kg in weight and 3.2 cm in height during this period and has not experienced difficulty swallowing solid foods. Esophagogastric dissociation with placement of an isolated jejunal segment between the esophagus and pylorus may have a useful role in the surgical management of multirecurrent symptomatic GER as a "rescue procedure" with low risk compared with other options.

Comparison of intratracheal pulmonary ventilation with hybrid intratracheal pulmonary ventilation in a rabbit model of acute respiratory distress syndrome by saline lavage.

We compared different hybrid mode ITPV (h-ITPV) flow rates, and h-ITPV with intratracheal pulmonary ventilation (ITPV) with respect to CO2 clearance and oxygenation. Surfactant deficiency was induced in six adult rabbits with saline lavage. The study consisted of three phases. Phase 0: Stabilization on conventional mechanical ventilation (CMV). Phase I: Bias flow initiated at same pressure and respiratory rate as Phase 0. Flow rates of 25%, 50%, 75% h-ITPV, and ITPV were initiated. Animals were transitioned from CMV to 25% h-ITPV proceeding sequentially to ITPV or vice versa. Phase II: Animals were returned to CMV. Statistical analysis included the two-way analysis of variance (ANOVA) and repeated measures ANOVA with Tuckey's test. No difference in PaCO2 was observed among all h-ITPV flow rates or between h-ITPV and ITPV. After bias flow was introduced (transition from Phase 0 to Phase I), PaCO2 decreased by 37%. PaCO2 increased by 119% during Phase II. Oxygenation improved in all animals, particularly in those transitioned to 25% h-ITPV and proceeding to ITPV. No difference in CO2 clearance between ITPV and h-ITPV was observed. Even at low bias flows, excellent CO2 clearance was achieved. Oxygenation was superior when animals were transitioned from CMV to h-ITPV. Hybrid-ITPV offers some advantages over ITPV and may represent a powerful tool in the management of acute respiratory distress syndrome (ARDS).

Gastric emptying after fundoplication is dependent on changes in gastric volume and compliance.

BACKGROUND/PURPOSE: Nissen gastroesophageal fundoplication (GEF) increases gastric emptying (GE); however, the duration and the mechanisms for this improvement in GE remain unclear. The aim of this study was to evaluate the effects of a GEF on GE of a mixed meal, and to determine the correlation between GE and changes in intragastric pressure (IGP) and compliance. METHODS: Using a radiolabeled mixed meal, GE was measured preoperatively 15 and 30 days after operation in 24 Sprague-Dawley rats divided into SHAM and GEF groups. Results were expressed as percent gastric retention at 90 minutes (GRg90), and time to evacuate 50% of the isotope meal (T1/2). Changes in IGP and compliance were determined at the same time-points using a different set of 20 rats. RESULTS: Fifteen days after surgery, GR90 and T1/2 in the GEF group were reduced significantly when compared with preoperative values but returned to near preoperative values 30 days postoperation. In contrast, rats from the SHAM group showed no change in GR90 and T1/2 at 15 days and 30 days postoperation. Immediately after GEF, maximal distension of the stomach resulted in pressures 65% higher than those recorded before operation (20.2 v 11.7 mm Hg; P< .05), which persisted on the 15th postoperative day (17.7 v 10.7 mm Hg; P<.05). On the 30th postoperative day, however, there was no difference in the IGP between rats undergoing GEF compared with those undergoing a SHAM operation (11.7 v 12.0 mm Hg; P < .05). Similarly, mean gastric compliance decreased significantly immediately after and 15 days after GEF, but returned to preoperative levels 30 days after the operation. CONCLUSIONS: In a rat model, GEF produces a transitory increase in GE, which is related to a simultaneous decrease in gastric volume and compliance. However, 30 days after GEF, associated with an elevated IGP, gastric volume increases and GE returns to preoperative levels.