CMAJ : Canadian Medical Association journal = journal de l'Association medicale canadienne
-
Dehydrated patients usually present with an elevated serum urea level, owing in part to increased renal reabsorption of urea mediated by antidiuretic hormone (ADH). We carried out a study to examine whether, during dehydration, the variations in the serum urea level could discriminate patients with central diabetes insipidus (CDI) from those with dehydration not due to CDI. We studied retrospectively 27 episodes of dehydration in 23 patients with CDI and 14 episodes in 14 patients without CDI. ⋯ In the patients with CDI a positive correlation was found between the magnitude of diuresis and the percentage decrease in the serum urea level compared with the level before dehydration (p less than 0.001). In the patients with CDI the serum urea level returned to the level before dehydration after the administration of vasopressin; a striking increase in the clearance of urea, which exceeded the creatinine clearance, was observed during dehydration in the three patients in whom clearance studies were done. The results suggest that serum urea values can be used to distinguish patients dehydrated because of CDI from those with hypertonic dehydration but without ADH deficiency and that during dehydration the net reabsorption of urea is dependent on the renal action of ADH.
-
Comparative Study
Haemophilus influenzae meningitis in Manitoba and the Keewatin District, NWT: potential for mass vaccination.
A community-based surveillance study of all central nervous system infections was carried out in Manitoba and the Keewatin District, NWT, between Apr. 1, 1981, and Mar. 31, 1984. There were 201 cases of bacterial meningitis in Manitoba over the study period, 81 (40%) caused by Haemophilus influenzae; all but one isolate tested were type b (Hib). There were nine cases of H. influenzae meningitis in the Keewatin District. ⋯ The age at onset was earlier in native Indian children (22 cases) and Inuit children (9 cases) than in non-native children (59 cases) (p less than 0.005); thus, vaccine prevention of Hib meningitis will likely be more difficult in native Indian and Métis children. Without evaluating the increased potential of H. influenzae vaccines to prevent nonmeningitic forms of disease, we concluded that mass childhood vaccination with polyribosylribitolphosphate (PRP) vaccine is not warranted in Manitoba or the Keewatin District. Immunogenicity studies suggest that administration of conjugated Hib vaccines such as PRP-D in infancy may prevent approximately one-third to two-thirds of cases of H. influenzae meningitis; these vaccines warrant consideration for use in mass childhood vaccination programs.
-
Review
Extrication, immobilization and radiologic investigation of patients with cervical spine injuries.
Most cervical spine injuries are due to motor vehicle accidents. Proper extrication of the victims is vital; the ideal device should be easily assembled and applied, should facilitate removal of victims from automobile seats without changing the body's position, must not hinder airway access or the performance of cardiopulmonary resuscitation, must accommodate all types of patients, including children and obese or pregnant patients, and must completely immobilize the patient, especially if hyperextension is suspected. Current methods of immobilization, such as the use of a soft collar and sandbags, allow neck extension; the short board protects against extension but interferes with airway access. ⋯ Radiologic examination of the first and second cervical vertebrae and the seventh cervical and first thoracic vertebrae should be emphasized. If lateral and anteroposterior views do not reveal abnormal findings and injury is still suspected, oblique views and computed or conventional tomography should be used. Cervical spinal cord injuries can be minimized or prevented if proper early management is applied.