Fetal behavioural states and controlled sound stimulation

The aim of this study was to investigate responses of human fetuses near term (37-42 wks) (increase/decrease of fetal heart rate and/or fetal motility) to acoustic stimuli. The study group consisted of 43 patients and the control group of 27 patients. Polygraphic recordings of 5 different fetal variables were carried out synchronously for the categorization of the actual fetal behavioural state according to Nijhuis et al. (Nijhuis, J.G., Prechtl, H.F.R., Martin, C.B., Jr. and Bots, R.S.A.M. (1982): Early Hum. Dev., 6, 177-195). Controlled acoustic stimulation was performed either with sine wave tone (2 kHz, 120 dB and 5 s duration) or modulated sine wave tone (0.5-2 kHz, 'sawtooth' modulation, 120 dB and 5 s duration). An additional group of patients received 'sham' stimulation. Overall 84 acoustic stimulations have been carried out. In 26 out of 84 stimulations (30%) a fetal response could be observed within 5 s after acoustic stimulation. In general, there were far fewer fetal responses in sleep states than in states of wakefulness. Whereas in state 1 F only 1 out of 28 acoustic stimulations was followed by an immediate fetal response, more responses were observed in state 2 F. An obvious increase in fetal reactivity to acoustic stimulation was noted in states of wakefulness (states 3 F and 4 F). Comparison between the true and sham stimulations revealed a relatively high level of spontaneous fetal activity (high variation of fetal heart rate and fetal motility) present in states 2 F and 4 F. This must be taken into account in all assessments of fetal responses.(ABSTRACT TRUNCATED AT 250 WORDS)

Transfusion reactions in cats due to AB blood group incompatibility

Blood transfusion reactions were investigated in 70 unsensitised and sensitised cats. Twenty-five compatible transfusions with respect to the AB blood group system did not result in any immediate transfusion reactions. Transfusion of B erythrocytes in 12 group A cats did not produce any severe reactions because of low anti-B titres in the A recipients. However, 30 of 50 group B cats (60 per cent) suffered severe shock reactions, characterised by marked hypotension, cessation of respiration and sometimes atrio-ventricular blocks, within two minutes of the injection of incompatible A cells (phase 1). From 35 seconds to five minutes later, markedly elevated blood pressures and extrasystoles were recorded (phase 2). The blood pressures generally stabilised within 30 minutes. Haemoconcentration and leucopenia were observed in severely reacting cats and leucopenia was also recorded in some A cats who received incompatible cells but did not exhibit transfusion reactions.

[Results and experiences with an autocorrelating ultrasonic cardiotocograph]

We present the results and experiences with a prototype cardiotocograph with US-autocorrelation processing. As this method is fundamentally different from conventional signal processing we are entering into the particular problems of this new FHR-technology. A total of 70 antepartum fetal rate recording from 53 patients and 38 intrapartum CTGs were evaluated. The antepartum results were excellent, the application time could be minimized and the quality of the recordings has been essentially improved. With the intrapartum recordings a computer comparison of long and short time irregularity of FHR derived from US-autocorrelation and direct fetal EKG was performed. The results proofed an excellent approximation to beat-to beat recording using the US-autocorrelation technique. The idea of using the new method intrapartum instead of invasive CTG could not be realised. This was due to a increasing loss of signal with progress of labor. To exclude maternal HR interferences the new monitor is supposed to record maternal heart rate simultaneously to FHR.

The influence of skull defects and reperfusion after extra-intracranial arterial bypass surgery on the sensorimotor EEG rhythm

Twelve patients with small burr hole skull defects after extra-intracranial arterial bypass surgery were studied. The amplitude and frequency of the sensorimotor rhythm were measured 7 days and 1, 2, 4, and 6 months after surgery in follow-up EEGs from the central region. Seven patients showed a frequency decrease (compared with preoperative measurement) on the operated side 7 days and/or 1 month after surgery. There was no case of frequency decrease 6 months after surgery; four patients displayed a late frequency increase. Ipsilateral amplitude enhancement was never found 7 days postoperatively, but after 6 months in nine patients. Such physical factors as burr holes and bone replacement can only partially explain the amplitude enhancement, and cannot explain the frequency decrease. It may be assumed that temporary clamping of the middle cerebral artery and/or reperfusion of an ischaemic area result in a brief deterioration of brain function, as indicated by frequency slowing and delayed amplitude enhancement; related observations were made in patients with cerebrovascular disorders and mild to moderate neurological deficit about 20 days after the onset and correlated with clinical recovery.

Blood transfusion reactions in the cat

The transfusion of only 4 ml of group A blood resulted in sudden death of a cat that was recovering from surgery. The clinical signs were similar in many respects to those exhibited by tranquilized group B cats when challenge exposed for the 1st time with incompatible A cells. The distribution of the A and B blood group antigens and the occurrence of naturally occurring isoantibodies in the cat were considered in relation to the probability of producing transfusion reactions. The results obtained with tranquilized and anesthetized cats demonstrated that immediate reactions can occur following the 1st transfusion of incompatible red blood cells. Cross matching with respect to the AB system is recommended before giving blood transfusions to cats.

A contribution to the monitoring of fetal arrhythmias

Antepartum and intrapartum monitoring problems are discussed with reference to a case history of a fetal AV-block detected during the 36th week of pregnancy. CTG instruments where the internal logic criteria can be turned off are suitable for monitoring arrhythmias. During labor the direct fetal ECG permits exact diagnosis as to the type of arrhythmia. The necessity of antepartum diagnosis in regard to postpartum pediatric management and hypoxic states during labor justify the large expenditure on monitoring apparatus. During labor continuous tissue pH measurement via the fetal scalp give added information as to fetal condition.

[A new oxytocin infusion rate recorder (author's transl)]

A new oxytocin-infusion rate recorder system is introduced. It provides continuous plotting dosages on the labor channel of the cardiotocogram. So far 82 conductions of labour were monitored with the new system and evaluated for oxytocin overstimulation. The rate of overstimulations could be reduced resulting in better fetal outcome.

Cerebral venous pressure during actively induced hypertension and hypercapnia in cats

Superior sagittal sinus pressure, intracranial pressure and arterial pressure were recorded in an experimental series on 10 cats. During drug-induced, severe, acute arterial hypertension and parallel hypercapnia, venous pressure could exceed intracranial pressure in both the supra- and infratentorial compartment. From these data it is concluded that cerebral venous pressure during acute arterial hypertension may contribute to protein extravasation at the postcapillary-venular level.

Medical versus surgical treatment of patients with cerebrovascular insufficiency. A retrospective comparative study

Report on a series of patients suffering from cerebrovascular insufficiency caused by stenosis and/or occlusion of one or several major cerebral vessels. The patients were divided in two groups, one being medically treated with anticoagulants, the other operated on either a carotid artery thrombosis by thromboendarterectomy or occlusion treated with an extracranial-intracranial arterial bypass. Results after a follow-up period of 1-3 years are compared and discussed in view of the recent literature.

Pial arteriolar reaction to intravenous administration of bencyclane in the cat

In a series of 29 experiments in cats, the vasodilatory effect of Bencyclane on pial arterioles was investigated by means of the cranial window technique, using an image-splitting eyepiece, a photometric method or simple microscopic observation. Intravenous injection of 3 mg kg-1 led to vasodilatation in all experiments, yet decreased blood pressure within 30--40 sec until 5--6 min down to 70% of resting pressure. Mean maximal dilatation of arterioles with a 76-micrometers mean resting diameter was 53%. After normalization of blood pressure, arteriolar diameters remained increased by 5--10% for further 10 min, thus indicating increased cerebral blood flow for a total time of about 15 min. During intravenous infusion of 0.2--0.3 mg kg-1min-1 of the drug, pial arterioles dilated by about 10% with blood pressure remaining on resting levels. A higher dosage rate of infusion evoked further vasodilatation, yet parallel decrease of blood pressure.

[Therapy of traumatic brain edema with spironolactone (author's transl)]

In 30 patients with severe brain injury a double-blind study was performed. The effectiveness of the aldosterone-antagonist Aldactone pro injectione was examined in therapy of traumatic brain edema. The results indicate elimination of sodium and water from brain cells and white matter. Concomitantly faster improvement of state of consciousness was observed.

Brain protease activity after experimental head injury

In an experimental series on twelve cats, activity changes of brain cell proteolytic activity were measured two hours after a blunt head injury without hematoma or contusions. Protease activity was estimated in two different brain tissue homogenate supernatants containing total soluble and only cytoplasmic activity without proteases in cell organelles, respectively. Total activity was doubled two hours after injury in the acid and the neural pH-range, in comparison to control values. Free soluble activity was doubled in the acid and increased to the threefold value in the neutral range. From these data, it seems that two different changes appear in lysosomes, the enzyme-reservoir of the cell: (1) Enzyme-synthesis is increased after trauma, measured as augmentation of total soluble protease activity in our experiments; (2) Breakage or increased permeability of lysosomes lead to augmentation of especially neutral proteases in the cytoplasm followed by the well known autolytic areas of generalized traumatic brain edema.

Azotaemia in severe head injury--central dysregulation or renal failure?

We have investigated serum urea, uric acid, and creatinin crealinine levels in 39 patients with craniocerebral trauma. The most impressive observation was a change in serum urea, which was found significantly increased up to 237 mg% on the seventh day (mean value) after severe injury, and turned out to be of great prognostic value. Patients with a serum urea above 100 mg% did not survive the acute stage. Uric acid and creatinine were only significantly increased in patients with lethal outcomes, the first being elevated by about 300% in the first week, the second remaining normal for four days increasing thereafter. It is concluded from these first data that a hypercatabolic state due to shock, central dysregulation, or both, is responsible for the dissociated behaviour of urea, uric acid and creatinine during the first four days, after which renal failure as a secondary change is shown by the rise in serum creatinine.

[Controlled hypotension with sodium nitroprusside in neurosurgical patients (author's transl)]

Sodium Nitroprusside (Nipride) was administered by infusion pump intravenously in 27 neurosurgical patients for intraoperative, postoperative and posttraumatic blood pressure lowering. This was accomplished with intension to reduce the risk of hemorrhage during operation on highly vascularized tumors or aneurysms and to combat hypertensive crisis after surgery and brain injury. The effect was documented by direct arterial blood pressure registration and the drug proved to be fast acting, potent and readily reversible. Dosage varied between 1 and 10 microgram/kg/min with systolic pressure decreasing about 6 to 60% of the initial value. There was ill correlation between infusion rate and blood pressure drop which demanded particular caution at the beginning and the end of infusion. A decrease in pulse pressure and a moderate tachycardia were generally observed, however no complications were seen due to a Sodium Nitroprusside administration over less than 12 hours duration in our series.

[Sodiumnitroprusside in neurosurgery and intensive care of neurosurgical patients (author's transl)]

Sodium nitroprusside (Nipride) was used in 35 patients between 16 and 72 years for induced hypotension. The fast and dose-dependent effect on the smooth muscles of the vessels made it superior to other methods of lowering blood pressure. Sodium nitroprusside was used to achieve hypotension in 11 patients (group I) with an aneurysm of a cerebral vessel and in 16 patients (group II) with highly vascularized cerebral tumors. In 8 patients (group III) from the neurosurgical intensive care unit a hypertensive crisis was interrupted. 10 patients (group IV) without induced hypotension were used as controls to compare the action of our standardized method of anesthesia on the observed parameters of blood pressure lowering. The average dose of sodium nitroprusside was 2.74 mcg/kg/min. in group I, 1.77 mcg/kg/min in group II and 1.27 mcg/kg/min in group III. The initial blood pressure was lowered between 30--40% in the mean in all 3 groups. Careful monitoring of the intra-arterial blood pressure, the central venous pressure, the cerebral fluid pressure, the arterial blood gases and the function of the kidneys during and after induced hypotension with sodium nitroprusside made it possible to take advantage of the blood pressure lowering effect also in patients with increased intracranial pressure.

Serum haptoglobulin changes in patients with severe isolated head injury

From a series of 74 patients with severe head injuries and massive brain lesions, we measured the changes in haptoglobulin in 33 cases. On average, the globulin was, after a short drop in the first two days, increased about three times towards the seventh day, and was still above normal after ten days. Seen together with the total alpha-2-globulin increase after head injury this rise seems mainly to be caused by the haptoglobulin changes. Haptoglobulin was found to be a good indicator of the extent of brain tissue damage. It cannot on its own be used for prediction of survival chances.

The action of sodium nitroprusside on the pial vessels

This study in cats investigates the action of sodium nitroprusside on the pial vessels by systemic and local administration, with an intravital microscopic window technique and a photometric technique for graphic documentation of vessel diameter changes. Intravenous infusion caused vasodilatation parallel with decreasing blood pressure. Pial arterioles dilated more than venules, smaller vessels more than larger ones. Local administration caused maximal dilatation within 5--10 seconds. With blood pressure returning to normal after i.v. therapy, pial vessels remained wider than they were before hypotension at the same pressure level. From these data it is concluded that the substance acts longer on the brain vessels than on vessels elsewhere in the body, and that cerebrovascular autoregulation to blood pressure changes is disturbed during this period.