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Biomedical subjects

K H Altemeyer

Publications and source records attributed to K H Altemeyer.

At least 19 recordsLinked to original sources

[Pediatric cases in preclinical emergency medicine: critical aspects in the range of missions covered by ground ambulance and air rescue services].

BACKGROUND: The aim of this study was to demonstrate differences in structure and severity of pediatric emergencies treated by aeromedical (air rescue) or ground ambulances services. Conclusions for the training of emergency physicians are discussed. PATIENTS AND METHODS: In a 3-year study period, a total of 9,274 pediatric emergencies covered by the ADAC air rescue service are compared to 4,344 pediatric patients of ground ambulance services in Saarland. RESULTS: In aeromedical services pediatric emergencies are more frequent (12.9% vs. 6.4%), trauma predominates (59.9% vs. 35.6%) and severe injuries or diseases occur more frequently (30.5% vs. 15.0%). In both groups pediatric emergency cases are concentrated into very few diagnostic groups: more than one third of the cases involving pre-school children is due to convulsions. Respiratory diseases and intoxication are the next most frequent causes and are more common in ground ambulance patients. Head trauma is the most common diagnosis in cases of pediatric trauma, followed by musculoskeletal and thoracoabdominal trauma. All types of severe trauma are more frequent in pediatric patients of the aeromedical services. CONCLUSIONS: Training of emergency physicians should include pediatric life support and specific information about frequent pediatric emergency situations. For emergency physicians in aeromedical services, an intensive training in pediatric trauma life support is also necessary.

Air Ambulances↗

[Preclinical care of trauma patients in air rescue. Results of the medical quality management for patients with severe head injury and polytrauma in the years 2000 and 2001].

In a retrospective study of mission data of ADAC Air Rescue of the years 2000 and 2001 the quality of preclinical care of 1,946 patients with severe head injuries and 1,878 polytraumatized patients was examined. The actual preclinical care of these patients was compared with a catalogue of eleven thesis-like recommendations. These recommendations were previously derived from corresponding publications of national and international specialist companies and were introduced in a binding manner by the senior doctors of the participating air rescue centres. The results of the study show that 73.3% of the severe head injuries were preclinically intubated and 94.4% were supplied with oxygen, 82.2% were analgosedated. 94.8% could be delivered to the hospital of destination. 65.9% had a systolic blood pressure of >120 mmHg upon admission to the hospital. 71.4% of severe head injury victims were equipped with a cervical support, 23.3% had the blood pressure documented. 47.3% reached the hospital of destination in less than 60 minutes. Among polytraumatic patients the intubation was performed in 75.7%, the supply with oxygen in 90.7%, 88.6% of the patients were analgosedated. 78.7% of patients suffering from concomitant head injuries were provided with a cervical support and only 22.8% had a blood sugar measurement documented. A concomitant severe thorax trauma was treated by a thorax drainage in 59.2%. 35.6% of the polytraumata reached the hospital of destination in less than 60 minutes. The work describes the preclinical patient care of severe head injuries and polytraumata, pointing out deficits and presenting optimization possibilities, particularly in the area of training. Furthermore, the work shows the concept of the medical quality management in an air rescue enterprise. The total evaluation of all air rescue centres participating in data collection forms the basis of an external quality comparison. The data evaluation of a single station makes regional strengths and weaknesses visible, deficits can be proven and proposals for optimization be developed. The presentation of the time history of data yields continuous standard information on the state of the patient care at the relevant air rescue location and enables the analysis of improvement concepts based on the updated data.

Air Ambulances↗

[Prerequisites for outpatient treatment using general anesthesia].

The possibility of profound preoperative examination by an experienced anesthesiologist, the cooperation of dentists, oral and maxillo-facial surgeons, anesthesiologists, pediatricians, internal specialists and family doctors, careful planning, conduction and supervision of anesthesia and postoperative treatment in a recovery room are essential in safe outpatient treatment under general anesthesia in the field of oral and maxillo-facial surgery. In case of unexpected postoperative complications patients have to be hospitalized. All the aforementioned requirements in respect of staff, apparatus and rooms must be fulfilled.

Adolescent↗

[Respiratory emergencies in childhood].

The most important maneuvers of primary treatment of respiratory emergencies in childhood are the securement of free airways, provision of oxygen and (medicamentous) tranquilization of the child. The most common causes of these emergencies are fulminant (infectious) diseases of the upper and lower airways, a particularly significant aspect being the considerable mucosal swelling as compared with adults. Aspiration of foreign bodies is a further cause of acute, life-threatening respiratory distress. Treatment requires a systematic examination and circumspection to achieve in the shortest time adequate temporary improvement until more extensive measures can be performed in the hospital.

Airway Obstruction↗

[Mechanical ventilation in an anesthetic circle system using the lowest tidal volume--studies of 3 anesthesia ventilators in a lung model and an animal experiment].

No anesthesia ventilator attached to a circle system is manufactured for use in neonates. However, a small bellows can be supplied for the following anesthesia ventilators: Spiromat NS 656 (NS), Ventilog 2 (V2) and AV1 (Draeger Co.) We investigated the minimal tidal volume delivered by each of the three ventilators. In addition, we tested the performance of the AV1 in neonatal piglets for manual and controlled ventilation, and in decreased lung compliance. MATERIALS AND METHODS. All circuits were equipped with one CO2 canister (750 ml) and the low-compliance tubes of the "Ulmer Kinder Set" (Ruesch Co.) The circuits were connected to a lung model consisting of a glass cylinder filled with copper wool with a compliance of 3.0 ml/mbar. By using calibrated glass syringes we created a pressure-volume correlation for the entire system, i.e., the lung model, the anesthesia circuit and the ventilator, which was linear for each of the three ventilators. The pressure was measured in the test lung. The pressure increase caused by the tidal volume therefore reflected the actual tidal volume delivered, which was calculated using the pressure-volume correlation. Tidal volumes were determined for varying the fresh gas flow (FGF), the respiratory rate (RR), which was varied between 20 and 60/min and the I:E ratio (IE), which was varied between 1:1 and 1:2. Six newborn piglets aged 2-12 h and with body weight 1000-1300 g were anesthetized, tracheotomized and ventilated with an oxygen-nitrous oxide mixture (FIO2 0.25). The manual ventilation lasted 30 min (period 1) and was followed by mechanical ventilation for 60 min (period 2). Thereafter, a left pneumothorax with constant pressure of 20 mbar and then 40 mbar for 15 min each was created (period 3). A fall in blood pressure was treated with 10 ml colloids in five of the six animals. During the experiment arterial blood pressure in the carotid artery, mean airway pressure at the distal end of the tracheal tube and end-tidal CO2 were continuously recorded. Arterial blood gases were analyzed at the end of each period. RESULTS. The tidal volumes delivered with an identical position of the bellows varied in ventilators NS and V2 with changes in FGF, RR and IE. Decrease in FGF, higher RR and longer expiration resulted in a decrease in the tidal volume. The "smallest" tidal volume delivered by NS varied from 50 ml (FGF 2 l/min, RR 60, IE 1:2) to 188 ml (FGF 4 l/min, RR 20, IE 1:1) and from 11 ml (FGF 2 l/min, RR 60, IE 1:2) to 110 (FGF 4 l/min, RR 20, IE 1:1) in the V2. The AV1 showed a minimal tidal volume of about 5 ml, and no changes in tidal volume attributable to alterations in FGF, RR or IE could be observed. No problems occurred during manual or mechanical ventilation in the piglets. With the experimental decrease in lung compliance no increase in airway pressure was noted, but an increase in arterial pCO2 by 8 mmHg (mean) reflects hypoventilation that was not corrected by the ventilator. DISCUSSION. We believe that the changes in tidal volume in ventilators NS and V2 are caused by adding FGF to the volume delivered by the below during inspiration. Because of the unpredictability of the tidal volumes, these ventilators are not suitable for the use in neonates. The AV1 has a very low systemic compliance which makes it suitable for use in neonatal anesthesia. However, a decrease in lung compliance is not compensated by an increase in airway pressure and leads to hypoventilation. When small tidal volumes are used in patients with low lung compliance, it does not act as expected of a volume-cycled ventilator.

Anesthesiology↗

The role of alpha 1-adrenoceptors in adrenaline-induced hyperkalaemia.

The hyperkalaemic action of adrenaline was investigated in 44 anaesthetized domestic pigs. Plasma and epicardial concentrations of K+ were measured, in the latter case with an ion-selective electrode. Adrenaline 10 micrograms kg-1 caused a rapid increase in the plasma concentration of K+ from 4.2 to 5.9 mmol litre-1. The magnitude and the time course of epicardial concentration of K+ were similar. Alpha-adrenoceptor block with either phentolamine 5 mg kg-1 (non-selective block) or prazosin 0.1 mg kg-1 (selective alpha 1-adrenoceptor block) abolished the hyperkalaemic effect of adrenaline in the plasma and on the epicardium. The alpha 1-adrenoceptor agonist phenylephrine increased the K+ concentration, but the alpha 2-adrenoceptor agonist UK 14.304 did not cause any change in concentration. These results suggest that the hyperkalaemia induced by adrenaline occurs in the interstitial fluid of the myocardium and is mediated by alpha 1-adrenoceptors. These findings may be important in patients at risk of hyperkalaemia, with implications, for example, in the use of suxamethonium during induction of anaesthesia.

Adrenergic alpha-Agonists↗

[Perioperative infusion therapy in children].

An incorrect fluid therapy can lead to serious complications considerably more rapidly in children, especially in newborns and infants, than in adults. The pediatric patient has a limited range of compensation for maintenance of fluid and electrolyte balance. Precise knowledge of the physiological age-dependent fluid balance, i.e. the large extracellular space, the developing renal function, the increased metabolism, the acid-base state, the electrolyte balance with the relatively higher sodium and chloride requirements must be the basis of an adequate fluid therapy. The basic fluid requirement (normal fluid and electrolyte requirement) varies with age and is influenced considerably by environmental conditions, body temperature and metabolism. For substitution of this basic fluid requirement one-third to one-half strength electrolyte solution in 5% dextrose is used, the amount depending on age. The perioperative fluid requirement, however, has to be calculated with due consideration for the characteristic changes in fluid and electrolyte balance during anaesthesia and surgery, the preoperative fasting period, drug effects of anesthetics, hormonal changes and ventilation; it is higher than the basic fluid requirement (infants 6-8 ml.kg-1.h-1, toddlers 4-6 ml.kg.h-1, schoolchildren 2-4 ml.kg-1.h-1). For intraoperative fluid therapy infusions with an increased sodium concentration (70-100 mmol/l) or Ringer's lactate (Na+ = 130 mmol/l) must be used. On no account must electrolyte-free solutions, e.g., 5-10% glucose, be used intraoperatively, as they can lead to water intoxication. The third-space requirements compensate for the additional losses by drainage, third-space deficits by evaporation and gastric and enteral secretions.(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesia↗

[Comparative humidity measurements in semiclosed and semiopen systems with the additional use of artificial noses].

The administration of dry anesthetic gases for ventilation lasting more than 1 h leads to morphological changes of the tracheobronchial epithelium that may cause postoperative pulmonary complications. Therefore, additional humidification is suggested for ventilation during anesthesia, particularly when using semiopen breathing systems. Recommendations concerning the use of semiclosed systems are controversial: previous studies have shown sufficient humidification on the one hand, and insufficient water content in the inspired air on the other hand. In this study, comparative humidity measurements in a semiopen and a semiclosed system were carried out during anesthesia and mechanical ventilation. We particularly wanted to find out whether placement of the fresh gas inlet into the circle before or behind the soda lime canister influences the humidity of the inspired gas. In addition, we tested three types of "heat and moisture exchanges"--Engström "Edith", Siemens "Servo Humidifier", and Portex "Humid Vent". A total of 58 patients between 23 and 78 years of age were studied. They were divided into three groups. Group I: In 10 patients comparative humidity measurements were carried out using both a semiopen and a semiclosed system. Group II: The time course of water saturation during a 3-h period was determined in 10 patients ventilated with a semiopen and 8 patients ventilated with a semiclosed circle system. Group III: In 20 patients we tested the effect of "heat and moisture exchangers". All patients were intubated and ventilated with the Spiromat 656 and the Circle System 8 (Drger) that made ventilation in both a semiclosed and a semiopen system possible. The humidity measurements were carried out using a psychometric method.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

[Pharmacodynamics of vecuronium in infants during intravenous induction of anesthesia with ketamine].

The pharmacodynamic effects of vecuronium in children aged 1 to 6 years were investigated after intravenous induction of anaesthesia with ketamine, using an initial dose of vecuronium of 0.08 mg/kg body wt. 0.1 mg/kg body wt. The degree of neuromuscular blockade was determined by measuring the contraction force of the m. adductor pollicis after supramaximal stimulation of the ulnar nerve using an electromechanical device. The results (median, chi min and chi max) were as follows. For the initial dose 0.08 mg/kg body wt., the onset time was 150 s (110-360 s); total blockade: 5 of 9 children, D25 (duration of 25% recovery) 13 min (10-31); RI (recovery index): 8.5 min (6.0-14.5); D90 (duration of 90% recovery): 27 min (20-44). For the initial dose of 0.1 mg/kg body wt., the onset time was 135 s (80-300); total blockade: all children, D25: 19.5 min (12-32.5); RI: 8.75 min (6.5-13.5); D90 35 min (22-45). Only the D25 was significantly shorter using an initial dose of 0.08 mg/kg body wt. For a total blockade, a higher dose of vecuronium is necessary using intravenous induction of anaesthesia compared with previously described inhalation techniques. Even with the high dosage, recovery from neuromuscular blockade is so rapid in this age group that it can be used even for short operations without reversal.

Anesthesia, Intravenous↗

[Pulse oximetry as a continuous, noninvasive monitoring procedure. Comparison of 2 instruments].

Pulse oximetry allows continuous registration of the arterial oxygen saturation by using the light absorption in a wave range between 600 and 1,000 nm. In addition the peripheral pulse is determined by a plethysmographic method. Two new devices, the Biox III pulse oximeter and the Nellcor pulse oximeter were compared for the following three items: 1. The accuracy in comparison with a simultaneously determined arterial oxygen saturation. Concerning the Biox III instrument, the correlation coefficient resulted in r = 0.90, for the Nellcor device in r = 0.92. 2. The onset time for registering a suddenly appearing hypoxia: For the Biox III oximeter we found a time lag between 6 and 42 s (median 21 s), for the Nellcor Oximeter between 12-39 s (median 21 s). 3. The pulse frequency corresponded very well with the simultaneously registered heart rate of the ECG. Our results indicate that pulse oximetry--a continuous and noninvasive method--is a reliable monitor for oxygen saturation, and provides trend informations about circulation, both of which are particularly appropriate for patients breathing spontaneously.

Adult↗

[The semi-closed filter circuit].

In a semi-closed circle system, the inspiratory and expiratory limbs are completely separated and part of the patient's expired air recirculates. CO2 rebreathing is prevented by CO2- absorption with soda lime, which is always incorporated in such a circle. The inspiratory and expiratory valves ensure that gas flow is unidirectional and also prevent rebreathing, even at tidal volumes of 10 ml and ventilation frequencies of 60 c . min-1. This circuit can be used as an universal anaesthetic system for all age groups, simply by changing the hoses and connecting pieces. The values of expiratory resistance are within the recommended limits of the ISO; prewarming and humidification of the inspiratory gas mixture are sufficient without additional equipment. Standard monitoring of the circuit such as measurement of inspiratory O2 concentration and ventilation pressure, including a disconnection alarm, can be used for all age groups; spirometry or end-tidal CO2 measurements ensure normoventilation. The fresh gas flow required in a semi-closed circle system is about 2-4 1 . min-1, so that costs and environmental contamination with anaesthetic gases are relatively low in comparison with a semi-open system.

Airway Resistance↗

[Massive intraoperative lung embolism caused by the introduction of a telescope pin (Bailey-Dubow pin) in a child with osteogenesis imperfecta].

We report the case of a massive pulmonary embolism in a three year old boy with osteogenesis imperfecta during a closed insertion of a Bailey-Dubow-rod. An increased intramedullary pressure with consecutive entering of medullary particles or air into the blood stream due to the insertion of the Bailey-Dubow-rod is discussed as the cause of the pulmonary embolus.

Brain Edema↗

[Blood glucose, ACTH, cortisol, T4, T3 and rT3 after cholecystectomy. Comparative studies of continuous peridural anesthesia and neuroleptanalgesia].

15 patients (12 women and 3 men) undergoing cholecystectomy were randomized into two groups. 8 patients were operated on under continuous thoracic epidural anaesthesia in combination with light general anaesthesia. Postoperatively they were kept painfree by continuous infusion of an 0.125% solution of bupivacaine via epidural catheter at a rate of 0.25-0.3 ml/kg X h over a period of four days. The 7 patients in the control group were operated on under neuroleptanalgesia. Piritramide was given for postoperative analgesia. All patients received 40 ml/kg X day of electrolyte solution during the period of investigation. Blood was collected at 8 am, 12 am, 4 pm, 8 pm, and 12 pm on the day of operation and on the third postoperative day, at 8 am on the first and second postoperative day, and at 8 am, 12 am, and 4 pm on the fourth postoperative day. Plasma glucose, ACTH, cortisol, T4, T3, and reverse T3 were measured. During the operation and for 12 h thereafter a mild hyperglycaemia was observed in the neuroleptanalgesia group but not in the epidural group. The differences were significant. A rise in ACTH was seen in both groups during and shortly after operation. The increase in cortisol concentration following this ACTH release was significant only in the neuroleptanalgesia, but not in the epidural group. From the first to the fourth postoperative day ACTH levels were low and cortisol concentrations within the normal range. On the third day it appeared that a diurnal variation in cortisol levels was again present. Cortisol suppression following the administration of 2 mg dexamethasone on the fourth postoperative day was detectable in both groups. Of the thyroid hormones, T4 remained unchanged and at a normal level during the investigation. T3 decreased and reverse T3 increased significantly, the maximum rise being observed on the second day. There were no differences between the groups. These changes are defined as low T3 syndrome, following caloric deprivation, injury, and stress. The metabolic and hormonal alterations caused by cholecystectomy are marked only during operation and shortly thereafter and only in this period are they influenced by epidural analgesia. From the first postoperative day onwards they are almost negligible so that a mitigation by using continuous epidural analgesia is not to be expected.

Adrenocorticotropic Hormone↗

[Post-traumatic metabolism--bases and clinical aspects].

In order to rationalize the nutritional therapy of polytraumatized patients we have developed a concept to explain the humoral response and subsequent metabolic reactions to trauma, which is based on current reports in the literature and our own investigations. Three separate phases should be defined. a) The acute phase: catecholamines dominate in the initial phase following severe trauma. Insulin secretion is suppressed, and the levels of the anti-insulin hormones glucagon, cortisol and growth hormone are increased. Under modern conditions of treatment this phase lasts between 12-24 h. Nutritional therapy cannot be carried out during this phase of maximal glycogenolysis, lipolysis and gluconeogenesis because of the danger that a major metabolic imbalance might develop. b) The intermediate phase: This phase can be said to occur when after 12-24 h the primary stabilisation of the acute phase is complete. Insulin secretion can now be stimulated, but the levels of anti-insulin hormones remain high. This phase lasts for a number of days. The gradual introduction of nutritional therapy is now possible, but the danger of metabolic imbalances arising when abrupt substrate increases are made is nevertheless present. Should complications arise this phase can at any time revert to the acute phase. Patients who are only slightly injured or have undergone moderately extensive surgery are from the onset in this phase. c) The repair phase: In uncomplicated cases the intermediate phase passes after a number of days into the repair phase. This stage lasts for a number of weeks and is dominated by the presence of insulin. The levels of the anti-insulin hormones have returned to normal values.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

[Behavior of plasma amino acids, blood sugar, insulin and glucagon in the early post-traumatic phase with sole substitution of fluid and electrolytes].

The findings on the changes in amino acid metabolism and hormonal regulation after severe trauma and the conclusions draw from these are rather controversial. It is well documented that even small amounts of carbohydrates may significantly influence amino acid and carbohydrate metabolism especially in stress situations. Very few studies have been carried out on polytraumatized patients given an absolutely carbohydrate-free diet however. The following study was carried out on 20 polytraumatized, ventilated patients, substituted with water and electrolytes only over a period of 4 days after trauma. Besides amino acids in plasma and urine, blood glucose, insulin and glucagon levels were determined every day as was energy expenditure, nitrogen excretion and parameters reflecting homeostasis. The total plasma amino acid concentration showed a slight increase, but remained nearly unchanged and within the reference range over the entire period of investigation. The plasma branched chain amino acids showed the most marked change. Their total concentration increased continuously from the first (median: 301 mumol X l-1), to the 4. day (median: 743 mumol X l-1) after trauma. Less affected, but also submitted to marked changes in plasma concentration in the early period after trauma were alanine, proline and phenylalanine. Although blood glucose concentrations were high, and clearly above reference range, insulin concentrations remained relatively low at all times (median: 24 microU X ml-1) while plasma glucagon concentrations were increased at all points of measurement (median: 327 pg X ml-1).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗