Cervical auscultation of suckle feeding in newborn infants

The authors recorded the sound signals during suckle feeding of six normal infants within the first two postnatal days. The sounds were recorded onto a cassette tape-recorder from a small microphone attached to the infant's neck, then displayed on an oscilloscope and analysed by digital signal processing techniques. These displays demonstrated acoustic patterns and temporal relationships which are not otherwise audible. The method and findings are described in detail, and the method should be useful in the clinical investigation of feeding and swallowing problems associated with more subtle neurological impairment and preterm birth.     

Sensory Visual Loss And Cognitive Deficits In The Selective Attentional System Of Normal Infants And Neurologically Impaired Children

The ability of infants to shift their gaze laterally from a central target (fixation shift) was investigated in normal one- and three-month-old infants in two visual tasks; competition (central fixating stimulus remained visible while peripheral target was presented) and non-competition (central fixating stimulus replaced by peripheral target). The younger infants were significantly more disrupted by the competition condition, in terms of latency to refixate and direction of first eye movement. An immature attention system is proposed to explain this affect. In addition, visually evoked potentials in response to comparable stimuli were easier to elicit in older infants, suggesting that the one-month-olds possessed more immature sensory and perceptual visual systems, as well as poorer neural systems for controlling selective attention. Both techniques have been applied to a group of neurologically impaired children, and the results indicate that the tests may be useful in distinguishing sensory loss from attentional impairments in these patients.     

Development of human cochlear active mechanism asymmetry: involvement of the medial olivocochlear system?

To study the functional development of the medial olivocochlear system, transient-evoked otoacoustic emission suppression experiments were conducted in 73 ears of 38 pre-term and 11 full-term neonates. The continuous contralateral stimulation was a broad band white noise, presented at 70 dB SPL. Efferent suppression was determined by subtracting the without-contralateral stimulation condition from the with-contralateral stimulation condition. Across this population, a mean suppression effect of contralateral stimulation on transient-evoked otoacoustic emissions was found, with most of the suppression effect observed after 8 ms. The amount of suppression is linearly, positively correlated with the conceptional age. In the subgroup of bilaterally tested neonates, the suppression of transient-evoked otoacoustic emissions is similar in the right ear and the left ear in subjects whose conceptional age is less than 36 weeks and significantly higher in the right ear than in the left ear in older neonates. This last observation was seen at frequencies where transient-evoked otoacoustic emission amplitudes became higher in the right ear than in the left ear as the conceptional age increased, a finding already reported in adults. This study shows that the functional adult pattern of the medial efferent system, probably involved in the detection of signals in noise such as speech sounds, seems to appear gradually in neonates and represents one of the several arguments in favor of functional auditory lateralization in humans, with a right ear advantage.     

Effects of thrombin, acetyl salicylic acid and prostaglandins on spontaneous efflux of norepinephrine and beta-thromboglobulin from platelets in calcium/magnesium deficient environment

The effect of different substances on the spontaneous efflux of 14C-norepinephrine (14C-NE) and beta-thromboglobulin (beta TG) from platelets in Ca2+ - and Mg2+ - free buffer was tested. Addition of increasing concentrations of thrombin (0.015-0.625 U/ml) resulted in an immediate increase of 14C-NE detectable in the supernatants, but the slopes of the efflux curves from 10 min after thrombin addition were almost identical and parallel with the slope before thrombin addition. Also beta-thromboglobulin was steadily released after thrombin addition. Prostaglandin E1 and prostacyclin in concentrations that gave a 30-fold increase in cAMP accumulation resulted in a moderate decrease in efflux of 14C-NE from 10 to 30 min but did not influence the efflux thereafter up to 80 min. Acetyl salicylic acid in vivo and in vitro (200-500 mumol/l) did not influence the efflux of 14C-NE or beta TG. The conclusions are that factors known to exert considerable effects on aggregation, desaggregation and acute release produce only transitory effects in a Ca2+ - and Mg2+ - free environment and that the basal efflux of alpha-granule components seems to be a stable process.     

Risk of rupture of postangiographic femoral false aneurysm.

The surgical management of 50 false aneurysms caused by transfemoral arterial catheterization was reviewed to document the incidence and effects of rupture before repair. Twelve false aneurysms ruptured, leading to shock in six patients, distal ischaemia in three and stroke in one. The mean(s.d.) time from catheterization to rupture was 2.8(1.7) (range 1-6) days. Postoperative complications occurred in seven patients with ruptured and eight with non-ruptured aneurysms (P < 0.04). The mean(s.d.) age of patients with ruptured aneurysms was 67.2(6.3) (95 per cent confidence interval 63.5-70.8) years and those without 58.5(9.1) (95 per cent confidence interval 55.3-61.7) years (P < 0.008). On multiple regression analysis, age, peripheral vascular disease and raised plasma liver enzyme levels on admission were found to be significant independent predictive variables for rupture (all P < 0.05). It is recommended that patients with these risk factors undergo urgent operative correction of femoral false aneurysm.     

Use of the Hickman catheter for central venous access in patients with haematological disorders.

Hickman catheters were inserted for access in the management of 70 patients with haematological disorders. Twelve patients received a second and one patient a third catheter. The resultant 16,283 catheter-day experience is reviewed. The complication rate was 0.28 per 100 catheter days. Sepsis in the form of catheter-related septicaemia (CRS) and exit site infection was responsible for 72% of complications. Staphylococcus epidermidis was the commonest organism isolated from cases of CRS. Patients receiving broad spectrum antibiotics on the day of catheter insertion were significantly less prone to catheter failure due to CRS or exit site infection (P = 0.008). The Hickman catheter is a useful and reliable method of maintaining central venous access, but prospective randomised trials are required to evaluate the role of prophylactic antibiotics in reducing the incidence of CRS.     

Sobriety as a Symptom of Alcohol Intoxication: A Clinical Commentary on Intoxication and Drunkenness

Intoxication and drunken behavior are related but not identical phenomena. Certain biological, psychomotor and psychological effects define intoxication. On the other hand, drunken behavior is to a great extent culturally defined and is related to variables such as time, place, environmental cues, social atmosphere, role expectations, attitudes and psychological needs. A common denominator for both is alcohol imbibition. The behavior of an intoxicated alcoholic does not have to be drunken. In support of this position, a case is presented showing that an alcoholic–whose drinking behavior is characteristically maladaptive–was able to display socially integrative behavior while exposed to substantial amounts of alcohol. This finding was not fortuitous. Twenty-nine other alcoholics received alcohol according to a two-day drinking schedule. The men initiated and stopped drinking on request and did not display provocative behavior while drinking. The study demonstrates that it is possible to initiate and easily terminate periods of drinking in alcoholics. This may represent a first step in the process of teaching alcoholics to drink without exhibiting socially disruptive behavior.     

Afferent neural pathway in the regulation of cardiopulmonary responses to tissue hypermetabolism.

We studied the role of neural transmission from hypermetabolic peripheral tissues in the regulation of cardiac output and pulmonary ventilation in chloralose-anesthetized dogs. Cross-circulation techniques with femoral-femoral or femoral-aortic anastomoses were used to produce a vascularly isolated, but normally innervated, hindlimb or lower half-body, 2,4-Dinitrophenol (DNP) was infused into the arterial side of the perfusion circuit to triple oxygen consumption and to increase lactate production by the cross-perfused area. After infusion of DNP, cardiac output and mean systemic arterial blood pressure increased, but neither heart rate nor pulmonary artery wedge pressure changed significantly. Pulmonary minute ventilation and arterial pH also increased, while arterial PCO2 fell. These changes were abolished when the nerve connections between the perfused limb and its parent body were severed. Normal saline, when administered in a similar manner, did not increase either ventilation or cardiac output, and simple denervation without previous infusions of DNP also had no effect. These results indicate that there are receptors sensitive to metabolic changes in the tissue, and that neural transmission is an important afferent link in regulating the cardiopulmonary responses to increased tissue metabolism.     

Clotted hemopericardium with the hemodynamic characteristics of constrictive pericarditis

Cardiac catheterization in a patient 4 weeks after coronary arterial bypass surgery demonstrated the typical hemodynamic findings of constrictive pericarditis, which completely resolved after removal of 500 ml of clotted pericardial blood. The pericardium was not responsible for the findings because it was left in place. This case demonstrates that clotted hemopericardium may mimic constrictive pericarditis.