Gastroesophageal pH step-up inaccurately locates proximal border of lower esophageal sphincter

Limiting the widespread use of 24-hr pH monitoring is the necessity of manometrically placing the pH probe 5 cm above the proximal lower esophageal sphincter (LES) border. Therefore, we prospectively compared LES localization by gastroesophageal pH step-up with manometry in 71 patients and 14 asymptomatic volunteers. The gastroesophageal pH step-up significantly correlated with the proximal LES border in patients (r=0.53, P<0.0001) and volunteers (r=0.91, P<0.0001). Based on previously published criteria, the pH step-up value was considered acceptably accurate if it was within ±3 cm (6 cm total span) of the manometrically determined proximal LES border. In 58% of patients and 29% of volunteers the pH step-up occurred outside this accuracy range. Esophagitis (P=0.015) and abnormal reflux parameters (P=0.002) were variables contributing to this error. Subsequent analysis found that the pH step-up overestimated the proximal LES border and occurred at the midportion of the sphincter. The pH step-up still inaccurately located the mid LES in 34% of patients. Therefore, manometry should remain the standard for accurate LES localization prior to placing the pH probe.     

Sensitivity and reproducibility of chemical tests for fecal occult blood with an emphasis on false-positive reactions

In 20 healthy volunteers ingesting 5 to 50 ml of⁵¹Cr-red cells, reaction intensities obtained with four chemical methods for fecal occult blood were compared with the “true” blood loss simultaneously determined by radioassay of each stool. Dilute tincture of guaiac reagent was found to have the same sensitivity and high frequency of false-positive reactions as the saturated guaiac reagent, but was more reproducible. Hematest^TM was slightly less sensitive but was poorly reproducible and yielded frequent false-negative as well as false-positive reactions. False-positive reactions by both methods were not eliminated by a meat-free diet; they were increased with guaiac reagents if stools were stored for 3 or more days. A new guaiac method (Hemoccult^TM) was found to be one-fourth as sensitive as the older tests, but was virtually free from false-positive reactions, even on an unrestricted diet and after storage of the stool specimens. It is recommended that the use of Hematest be abandoned and that Hemoccult be used preferentially if future studies confirm that its sensitivity is sufficient to detect most gastrointestinal lesions which are yielding occult blood.     

Lateral spread response monitoring during microvascular decompression for hemifacial spasm

Aim

The aim of the present study was to determine (1) whether successful intraoperative electromyography monitoring for lateral spread response (LSR) is possible with partial neuromuscular blockade (NMB) in subjects undergoing microvascular decompression (MVD) for hemifacial spasm and (2) the adequate level of NMB to achieve that goal.

Material and methods

A total of 61 patients in whom LSR was monitored during MVD were enrolled in the study. Patients were randomly allocated to two groups: group TOF in which the NMB target was maintenance of two train-of-four (TOF) counts and group T1 in which the NMB target was maintenance of a T₁/Tc ratio of 50?% (T₁: first twitch height of TOF and Tc: control twitch height). The adductor pollicis brevis muscle was used to monitor TOF responses. The frequency of successful LSR monitoring, defined as successful baseline establishment and maintenance of LSR until surgical decompression, was compared between the two groups.

Results

Of the 61 patients 2 were excluded from the study so that 30 patients in group TOF and 29 patients in group T1 were analyzed. The success rate of LSR monitoring was clinically acceptable and significantly higher in group T1 than in group TOF, i.e. n?=?15 (50.0?%) in group TOF versus n?=?24 (82.8?%) in group T1 (P?=?0.008), corresponding to a 32.8?% higher success rate in group T1 than group TOF (95?% CI: 13.9–51.7?%). Mean vecuronium infusion dose was smaller and mean TOF count was higher in group T1 than group TOF with a TOF count =?2 (1) in group TOF versus 3 (1) in group T1 (P?=?0.003). Mean sevoflurane and remifentanil infusion doses were not different between groups. There was no incidence of spontaneous movement during microscopy in either group.

Conclusion

Maintenance of partial NMB with a target T₁/Tc ratio of 50?% resulted in a clinically acceptable success rate of LSR monitoring and surgical condition during MVD. Maintenance of partial NMB with a target T₁/Tc ratio of 50?% rather than TOF count of two during LSR monitoring for MVD can therefore be recommended.     

Ischial apophyseal fracture in an abused infant

We report a previously healthy 4-month-old who presented to the hospital with leg pain and swelling and no history of trauma. Radiographs demonstrated a comminuted left femur fracture. Given the concern for child abuse, skeletal survey was performed and revealed four vertebral compression deformities. Although abuse was suspected, the possibility of a lytic lesion associated with the femur fracture and multiple spinal abnormalities raised the possibility of an underlying process such as Langerhans cell histiocytosis. Subsequently 18F-NaF positron emission tomographic (PET) scintigraphy revealed increased tracer activity in the ischium, and MRI confirmed an ischial apophyseal fracture. Pelvic fractures, particularly ischial fractures, are extremely rare in the setting of child abuse. This case report describes the multimodality imaging findings of an ischial fracture in an abused infant.