Characterizing the need for mechanical ventilation following cervical spinal cord injury with neurologic deficit

BACKGROUND: Patients who sustain cervical spinal cord injury (C-SCI) with neurologic deficit may require a definitive airway and/or prolonged mechanical ventilation. The purpose of this study was to characterize factors associated with a high risk for respiratory failure and/or the need for mechanical ventilation in C-SCI patients. METHODS: Patients with C-SCI and neurologic deficit admitted to a Level I Trauma Center between July 1, 2000 and June 30, 2002 were retrospectively reviewed for demographics, level and completeness of neurologic deficit, need for definitive airway, need for tracheostomy, need for mechanical ventilation at hospital discharge (MVDC), and outcomes. The level and completeness of injury were defined by American Spinal Injury Association standards. RESULTS: One hundred nineteen patients with C-SCI and neurologic deficit were identified over this period. Of these, 45 were identified as complete C-SCI: 12 (27%) patients had levels of C1 to C4; 19 (42%) had a level of C5; and 14 (31%) had levels of C6 and below. There were 37 males and 8 females. There were 36 blunt and 9 penetrating injuries. The average age of these patients was 40 +/- 21, and the average ISS was 45+/-22. Eight of the patients with complete C-SCI died, for a mortality of 18%. Of the 37 survivors, 92% received a definitive airway, 81% received tracheostomy, and 51% required MVDC. All patients with complete injuries at the C5 level and above required a definitive airway and tracheostomy, and 71% of survivors required MVDC. Of the patients with complete injuries of C6 and below, 79% received a definitive airway, 50% required tracheostomy, and 15% of survivors required MVDC. Only 35% of incomplete injuries required a definitive airway, and only 7% required tracheostomy. CONCLUSIONS: The need for definitive airway control, tracheostomy, and ventilator dependence is significant, especially for patients with high complete C-SCI. Based on these results we recommend consideration of early intubation and tracheostomy for patients with complete C-SCI, especially for those with levels of C5 and above.     

Differential effects of halothane and isoflurane on lumbar dorsal horn neuronal windup and excitability

Background. Windup of spinal nociceptive neurones may underlietemporal summation of pain, influencing the minimum alveolarconcentration (MAC) of anaesthetics required to prevent movementto supramaximal stimuli. We hypothesized that halothane andisoflurane would differentially affect windup of dorsal hornneurones. Methods. We recorded 18 nociceptive dorsal horn neurones exhibitingwindup to 1 Hz electrical hindpaw stimuli in rats. Effects of0.8 and 1.2 MAC isoflurane and halothane were recorded in thesame neurones (counterbalanced, crossover design). Windup wascalculated as the total number of C-fibre (100–400 mslatency) plus afterdischarge (400–1000 ms latency) spikes/20stimuli (area under curve, AUC) or absolute windup (C-fibreplus afterdischarge–20xinitial response). Results. Increasing isoflurane from 0.8 to1.2 MAC did not affectAUC, but increased absolute windup from 429 (62) to 618 (84)impulses/20 stimuli (P<0.05) and depressed the initial C-fibreresponse from 14 (3) to 8 (2) impulses (P<0.05). Increasinghalothane from 0.8 to1.2 MAC depressed AUC from 690 (79) to537 (65) impulses/20 stimuli (P<0.05) and the initial responsefrom 18 (2) to 13 (2) impulses (P<0.05), but absolute windupwas not affected. Absolute windup was 117% greater during 1.2MAC isoflurane compared with 1.2 MAC halothane. Conclusions. Windup was significantly greater under isofluranethan halothane anaesthesia at 1.2 MAC, whereas the initial C-fibreresponse was suppressed more by isoflurane. These findings suggestthat these two anaesthetics have mechanistically distinct effectson neuronal windup and excitability.     

A murine model of congenital toxoplasmic retinochoroiditis

A histopathological study of toxoplasmic retinochoroiditis in 39 eyes of mice infected in utero with Toxoplasma gondii and sacrificed at 16 weeks post-partum showed a wide variation in the pattern of tissue destruction. The changes in individual eyes were graded from mild to severe; Toxoplasma cysts were present in the retina and optic nerve in each grade. In the least affected eyes, Toxoplasma cysts were rarely seen and the disease was limited to a low grade uveitis and retinal lymphocytic perivasculitis. In the more severely affected eyes, there was focal, sectorial or total retinal destruction with secondary degeneration in the lens. In some eyes inflammatory destruction of the outer retina was associated either with a paucity of cells, or with lymphocytic infiltration or with plasma cell infiltration; giant cell granulomatous reactions were rare. In the most severely affected eyes the retina was necrotic and calcified. The findings illustrate the complexity of toxoplasmic retinochoroiditis and suggest that autoimmunity may play a part in the disease process.     

SPLEEN CELL PROLIFERATION IN RESPONSE TO HOMOLOGOUS ANTIGENS STUDIED IN CONGENIC RESISTANT STRAINS OF MICE

The proliferative responses obtained when spleen cell suspensions from two different inbred strains of mice were mixed were investigated further using congenic resistant strain pairs. Strong responses were obtained in 9 cases out of 12 where the two strains differed at a single gene locus controlling an H-2 histocompatibility antigen. No responses were obtained where the difference occurred at loci controlling weak histocompatibility antigens. These findings have been taken to provide additional circumstantial evidence that the response represents an in vitro homograft reaction to homologous tissue antigens.     

Colon perforation following percutaneous nephrostomy and renal calculus removal

Two patients had colonic perforation as a result of percutaneous nephrostomy placement followed by track dilatation and renal calculus removal. We present the technical aspects of nephrostomy placement and stone removal, as well as the clinical diagnosis and management of these cases. Both patients recovered well with conservative therapy and required no surgical intervention. This report reviews the anatomic considerations for percutaneous nephrostomy in patients undergoing renal stone removal.     

Three-dimensional preoperative maps of hippocampal atrophy predict surgical outcomes in temporal lobe epilepsy

The authors used surface-based anatomic mapping to detect features of hippocampal anatomy that correlated with surgical outcomes in patients undergoing surgery for mesial temporal lobe epilepsy with hippocampal sclerosis. Compared with a seizure-free group, hippocampal profiles for the non-seizure-free group had greater diffuse ipsilateral atrophy and more region-specific contralateral atrophy in the anterior, lateral hippocampus. These atrophic regions may indicate areas of increased epileptogenicity, contributing to poorer surgical outcomes.     

Use of the weight efficacy lifestyle questionnaire with African American women: validation and extension of previous findings

While the Weight Efficacy Lifestyle Questionnaire (WEL) shows promise as a measure of self-efficacy for eating control, there is a lack of research examining the psychometric properties of this measure with ethnic minorities. The current study examined the WEL with a sample of 144 overweight and obese African American females. Analyses indicated similar self-efficacy levels compared to predominantly Caucasian samples. Supporting the validity of the WEL, participants undergoing obesity treatment demonstrated modest improvement in WEL scores, while standard care participants showed no changes in self-efficacy over time. Factor analysis indicated a four-factor structure rather than the five factors previously found. The four-factor structure accounted for 61.85% of the variance. Results indicate the WEL may be a valid measure of self-efficacy for overweight and obese African American women, although researchers should be mindful of the variation in scale properties when using the WEL with this population.     

Pharmacokinetics, ovulation suppression and return to ovulation following a lower dose subcutaneous formulation of Depo-Provera

Depo-Provera is a highly effective contraceptive, given intramuscularly (150 mg/mL) once every 3 months. It has been in use in the United States for over 10 years. A new lower-dose formulation of Depo-Provera (104 mg/0.65 mL), has been developed that allows subcutaneous injection, potentially increasing the convenience, ease of administration and tolerability of this contraceptive. This prospective, randomized, single-center, single-dose trial evaluates the pharmacokinetics of the lower-dose formulation of Depo-Provera and compares the lower-dose formulation to the original formulation with regard to efficacy and duration of ovulation suppression and the return to ovulation at 12 months. While delivering a 30% lower total dose than the intramuscular formulation, the lower-dose formulation of Depo-Provera suppressed ovulation for more than 13 weeks in all subjects and was not affected by body mass index or race. Median time for return to ovulation was 30 weeks, with a 97.4% cumulative rate of return to ovulation at 12 months.