ALTHESIN, KETAMINE AND METHOHEXITONE AT PRESSURE-DURATION OF ACTION OF A SINGLE I.V. DOSE

General anaesthesia for emergency surgery in a pressurized habitatis likely to involve the use of i.v. agents. The anaestheticproperty of such agents is known to be antagonized by pressure,but the effect on their duration of action is not easily predicted.The recovery of mice from a single i.v. dose of Althesin, ketamineor methohexitone was estimated by their ability to remain uprightin a rotating drum. At 35 atm abs. duration of action was significantlyreduced: P<0.05 for Althesin; P<0.0l for ketamine andmethohexitone. A number of animals in each group, however, displayedrecovery times that were comparable to control. The convulsionrate with methohexitone was 60% at 35 atm abs., whereas at 1atm abs. it was 20%. The clinical implications of these findingsare discussed.     

The incidence and magnitude of fibrinolytic activation in trauma patients

Summary. Background:  Trauma is a global disease, with over 2.5 million deaths annually from hemorrhage and coagulopathy. Overt hyperfibrinolysis is rare in trauma, and is associated with massive fatal injuries. Paradoxically, clinical trials suggest a much broader indication for antifibrinolytics. Objective: To determine the incidence and magnitude of fibrinolytic activation in trauma patients and its relationship to clot lysis as measured by thromboelastometry. Methods: A prospective cohort study of 303 consecutive trauma patients admitted between January 2007 and June 2009 was performed. Blood was drawn on arrival for thromboelastometry (TEM) and coagulation assays. Follow‐up was until hospital discharge or death. TEM hyperfibrinolysis was defined as maximum clot lysis of > 15%. Fibrinolytic activation (FA) was deterined according to plasmin–antiplasmin (PAP) complex and D‐dimer levels. Data were collected on demographics, mechanism, severity of injury, and baseline vital signs. The primary outcome measure was 28‐day mortality. The secondary outcome measures were 28‐day ventilator‐free days and 24‐h transfusion requirement. Results: Only 5% of patients had severe fibrinolysis on TEM, but 57% of patients had evidence of ‘moderate’ fibrinolysis, with PAP complex levels elevated to over twice normal (> 1500 μg L^?1) without lysis on TEM. TEM detected clot lysis only when PAP complex levels were increased to 30 times normal (P < 0.001) and antiplasmin levels were < 75% of normal. Patients with FA had increased 28‐day mortality as compared with those with no FA (12% vs. 1%, P < 0.001), fewer ventilator‐free days, and longer hospital stay. Conclusions: FA occurs in the majority of trauma patients, and the magnitude of FA correlates with poor clinical outcome. This was not detected by conventional TEM, which is an insensitive measure of endogenous fibrinolytic activity.     

A PAEDIATRIC VENTILATOR WITH A FLUIDIC CONTROL SYSTEM

A paediatric ventilator has been designed basically as a fluidic-logiccontrolled T-piece occluder. Inspiratory and expiratory time,inflation pressure limit, positive end-expiratory pressure (PEEP),continuous positive airway pressure (CPAP) and inspiratory flow-rateare controlled independently and intermittent mandatory ventilation(IMV) is available. Warning systems are provided for failureof the driving gas, low airway pressure and pressure inspiratorypressure limit. The breathing circuit is isolated from the controland warning systems for ease of sterilization.     

Lack of in Vivo Mutagenicity and Testicular Toxicity of Triamterene in Mice

Lack of in Vivo Mutagenicity and Testicular Toxicity of Triamterenein Mice. MANSON, J.M., GUERRIERO, F.J., BROWN, T., AND SAN SEBASTIAN,J. (1986). Fundam. Appl. Toxicol. 7, 533-546. Triamterene (2,4,7-triamino-6-phenylpteridine),a widely used diuretic/antihyper-tensive agent with weak antifolateactivity, has been found to be positive in several in vitroassays for mutagenicity. The present studies were undertakento characterize the potential mutagenic and antifolate activityof triamterene in the bone marrow and testes of mice with invivo treatment. Triamterene had no clastogenic effects on thebone marrow at 6,16, or 24 hr after a single oral dose of 25,125, or 250 mg/kg. No alterations in hematopoietic cell maturationcharacteristic of antifolate action were observed in a dose-rangestudy in which triamterene was orally administered to mice at5-300 mg/kg/day for 5 days. Triamterene had no adverse effectson mating or fertility and did not induce dominant lethal mutationsin the germ cells of male mice when given for 5 days at 5-100mg/kg/day. Oral exposure to mice under identical conditionshad no effect on testicular weight, DNA content, or activityof the de novo pathway for thymidine synthesis from deoxy [6-3H]uridine.The present findings are consistent with an absence of mutageniceffect and antifolate action on the bone marrow and testes within vivo administration.     

Auditory brainstem evoked response as a hearing test in infants and children: A follow up study

Abstract In recent years the auditory brainstem evoked response (BSER) has become an established aid in assessing hearing in unco-operative subjects. We have reviewed our experience with this technique in 293 infants and children aged less than 11 years. We have found that the threshold for click BSER correlates well with the average audiometric threshold in the 2–4 kHz range. We have had encouraging preliminary experience to support the claim by other workers that 500 Hz stimuli may be used to assess low tone auditory function. In interpreting results it is important to appreciate that hearing levels may fluctuate with disorders such as otitis media and occasionally in cases of meningitis. Caution is also advised in interpreting results in cases where central nervous system pathology capable of affecting auditory pathways is known to exist.     

Spinal cord dysfunction with quadriplegia complicating pneumococcal meningitis

Abstract A case of pneumococcal meningitis complicated by brain-stem herniation and flaccid quadriplegia is described, from which the patient, an 11 year old boy, made a partial recovery. The patient had suffered a head injury with skull fracture some years previously; this was his third episode of meningitis. The aetiology of the quadriplegia has not been fully established, but is presumed to be of vascular nature at spinal cord level, associated with an acute hypotensive episode. Preventative aspects of recurrent bacterial meningitis and brain-stem herniation following lumbar puncture are stressed.