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Biomedical subjects

D Scheidegger

Publications and source records attributed to D Scheidegger.

At least 37 records · Page 2Linked to original sources

[Emergency therapy of burns].

Burns are among the most common accidental injuries, occurring in almost any environment to victims of all ages. Most of them are minor injuries and may be treated on an out-patient basis. Superficial (first-degree and superficial second-degree) burns will heal uneventfully in about two weeks without scarring, as long as no infection complicates the healing process. Major burns, however, are life-threatening, and professional treatment is crucial for survival. The intensive care and the surgical treatment in these patients demand a major commitment in terms of personnel and material resources; in addition, emotional reactions by any person involved in the case are not uncommon. A skilled and knowledgeable on-scene emergency treatment may diminish the depth of the burn wound and will furthermore reduce the number of complications like hypovolemic shock and infection. A complete clinical assessment including the patient history gives the rationale for any therapy and will help determine the appropriate referral center. The emergency treatment primarily includes the cooling of the burn wound to stop the burning process and to reduce pain, the insertion of an intravenous line, including the infusion of 1 to 2l of an isotonic electrolyte solution per hour, and the management of pain with intravenous boluses of morphine. The patient should also receive supplemental oxygen, and the burn wound should be covered by sterile drapes. Finally, every burn victim requires tetanus prophylaxis. Major burns and burn wounds at sensitive locations such as head and hands should be treated in specialized burn centers. This provides best chances for survival and increases the probability for a good cosmetic result.

Adult↗

[Surgery in pheochromocytoma. 12-year development].

Hypertension (sustained and/or paroxysmal) is the most common symptom of pheochromocytoma. Correct evaluation nearly always leads to the diagnosis, and complete surgical excision is the definitive treatment. Our study deals with preoperative evaluation, operative morbidity and long-term results after surgery. During the 12-year period (1981-1992) 31 patients (48 years, 25-85) with pheochromocytoma were treated at our institution. The selected preoperative management was reviewed on the basis of patient records. Long-term follow-up was carried out consecutively and personally. All patients received alpha-adrenergic blockers to achieve preoperative normotension and volume repletion. All resections were performed by laparotomy; two of the early cases were extended into the chest. 27 of 29 patients (93.1%) had elevated levels of urinary vanillylmandelic acid; a similar sensitivity was noted in the urinary catecholamines (24/26 = 92.3%). In anatomical localization CT-scan was accurate in 100% (27/27). MIGB scintigraphy was of help in 21 of 23 (91.3%) and, in the most recent patients, MRI was helpful in 3 of 3 (100%). No patient died during the first 30 days after surgery. One patient developed an anaphylactic reaction after cephalosporin administration (morbidity: 3.2%). 2 patients (6.4%) with malignant pheochromocytoma developed a recurrent tumor during the follow-up period. Resection of pheochromocytomas by laparotomy has a low perioperative morbidity and mortality after standardized preparation. A positive MIBG scintigraphy allows extra-adrenal localization. Better resolution and multiplanar imaging are the advantages of MRI. Perioperative management and new imaging techniques--eliminating arteriography and venous sampling among others--have simplified surgical treatment and improved its safety.

Adrenal Gland Neoplasms↗

B cell function in mice transgenic for mCTLA4-H gamma 1: lack of germinal centers correlated with poor affinity maturation and class switching despite normal priming of CD4+ T cells.

This report outlines the B cell phenotype of transgenic mice that overexpresses the mouse CTLA-4-human gamma 1 (mCTLA4-H gamma 1) protein. Despite the fact that these mice prime CD4+ T cells (Ronchese, F., B. Housemann, S. Hubele, and P. Lane. 1994. J. Exp. Med. 179:809), antibody responses to T-dependent antigens are severely impaired. In contrast, T-independent responses are normal which suggests mCTLA4-H gamma 1 does not act directly on B cells, but acts indirectly by impairing T cell help. The impaired antibody defect is associated with impaired class switching, with low total immunoglobulin (Ig)G and antigen-specific IgG responses, and an absence of germinal center formation in spleen and lymph nodes but not gut-associated tissues. The defective germinal center formation is associated with a reduction in the degree of somatic mutation in hybridomas made from transgenic mice in comparison with those made from normal mice. It seems likely that mCTLA4-H gamma 1 exerts its effect by blocking an interaction between T and B cells that induce T cell help for B cells.

Abatacept↗

[Invasive and non-invasive diagnosis of pulmonary hypertension in the intensive care unit].

The diagnosis of chronic primary and secondary pulmonary hypertension is difficult. Important indications result from physical examination and the patient's history. Non-invasive diagnostic tools are chest X-ray, ECG, blood gas analysis and 2-D-Doppler-echocardiography. If, despite these investigations, no reason for the pulmonary hypertension is found, perfusion scintigraphy of the lungs and a right-heart catheter investigation should be performed. If there is no intracardiac shunting and perfusion scintigraphy of the lungs is normal, repeated pulmonary embolism must be excluded by pulmonary angiography. Only after elimination of this possibility can primary pulmonary hypertension be regarded as the reason for the patient's condition. Pulmonary hypertension is usually more acute in the critically ill patient. Under these circumstances, only direct pressure measurements are of clinical relevance. In the critical care setting, many of the non-invasive methods are either difficult to perform or hard to interpret. Furthermore, many of the typical signs of pulmonary hypertension derived from non-invasive investigations do not appear in acute pulmonary hypertension.

Angiography↗

Human factors and safety in emergency medicine.

A model based on an input process and outcome conceptualisation is suggested to address safety-relevant factors in emergency medicine. As shown in other dynamic and demanding environments, human factors play a decisive role in attaining high quality service. Attitudes held by health-care providers, organisational shells and work-cultural parameters determine communication, conflict resolution and workload distribution within and between teams. These factors should be taken into account to improve outcomes such as operational integrity, job satisfaction and morale.

Emergency Medicine↗

Prolonged decrease in heart rate variability after elective hip arthroplasty.

The pattern of postoperative heart rate variability may provide insight into the response of the autonomic nervous system to anaesthesia and surgery. We have obtained spectral (fast Fourier transform) and non-spectral indices of heart rate variability from electrocardiographic recordings, sampled during continuous perioperative Holter monitoring in 15 otherwise healthy patients with an uncomplicated postoperative course, undergoing elective hip arthroplasty with either spinal or general anaesthesia. In both groups, total spectral energy (0.01-1 Hz), low-frequency spectral energy (0.01-0.15 Hz) and high-frequency spectral energy (0.15-0.40 Hz) decreased after surgery to 32% (95% confidence interval (CI) 10.5; P < 0.01), 29% (95% CI 12.5; P < 0.01) and 33% (95% CI 12.5; P < 0.01) of their preoperative values, respectively, and these indices remained suppressed for up to 5 days. Non-spectral indices decreased to a similar extent. These findings indicate a substantial and prolonged postoperative decrease in both parasympathetic and sympathetic influence on the sinus node.

Aged↗

[Surgical risk and anesthesia in geriatric patients].

The percentage of elderly people in our population is increasing, and anaesthesiologists and surgeons need to find ways of decreasing perioperative complications in these patients. The chronological age is of lesser importance than biological age as far as the risks of perioperative complications are concerned. Indicators for biological age are the number and type of previous diseases, nutritional status and the doctor's clinical impression of the patient. Preoperative evaluation of the perioperative risks in elderly patients is now mandatory. The physical status classification of the American Society of Anesthesiologists and the Goldmann Index are very useful for patient evaluation. Optimal preparation of the patient is helpful in decreasing risks, and the avoidance of emergency operations will also decrease risks. It is not yet clear whether regional anaesthesia, as opposed to general anaesthesia, decreases mortality in geriatric patients. It seems, however, that regional anaesthesia may have some advantages in terms of postoperative consciousness, blood loss, thrombotic complications and mean length of stay in hospital. The surgeon can help reduce the operative risk by a rapid and atraumatic operation technique. The most frequent perioperative complications are alterations to the cardiopulmonary system and postoperative bleeding. Even minor perioperative complications can have a predictive value for later fatal events. Thus, careful preoperative preparation, a suitable anaesthetic procedure and a fast and atraumatic mode of operation will help to decrease perioperative complications in elderly patients.

Aged↗

Follicular dendritic cells help resting B cells to become effective antigen-presenting cells: induction of B7/BB1 and upregulation of major histocompatibility complex class II molecules.

This study was designed to investigate whether follicular dendritic cells (FDC) can activate B cells to a state in which they can function as effective antigen-presenting cells (APC). High buoyant density (i.e., resting) B cells specific for 2,4-dinitro-fluorobenzene (DNP) were incubated with DNP-ovalbumin (OVA) bearing FDC, after which their capacity to process and present to an OVA-specific T cell clone was assessed. The efficacies of alternative sources of antigen and activation signals in the induction of B cell APC function were compared with those provided by FDC. Only FDC and Sepharose beads coated with anti-immunoglobulin (Ig)kappa monoclonal antibody provided the necessary stimulus. FDC carrying inappropriate antigens also induced B cell APC function in the presence of exogenous DNP-OVA. However, in circumstances where soluble DNP-OVA was limiting, FDC bearing complexes containing DNP, which could crosslink B cell Ig receptors, induced the most potent APC function. Analysis by flow cytometry revealed that within 24 h of coculture with FDC, a significant percentage of B cells increased in size and expressed higher levels of major histocompatibility complex class II. By 48 h, an upregulation of the costimulatory molecule, B7/BB1, occurred, but only when exposed to the FDC bearing DNP. Taken together, the results demonstrate that FDC have the capacity to activate resting B cells to a state in which they can function as APC for T cells. The stimuli that FDC provide may include: (a) an antigen-dependent signal that influences the upregulation of B7/BB1; and (b) possibly a signal independent of crosslinking mIg that results in Ig internalization. The relevance of these findings to the formation of germinal centers and maintenance of the humoral response is discussed.

Animals↗

[Technical aspects of rehydration].

Rehydration of terminally ill patients is from a technical point of view not more difficult than fluid treatment of any other patient. The difficulty lies in the balanced decision between the appropriate method on one hand and the desirability of a rehydration on the other hand. The route of choice in terms of burden for the patient as well as from a logistic point of view is the oral one. If it fails fluid can be administered via transnasal gastric tube. Percutaneous endoscopic gastrostomy and other types of gastrostomy do not provide any advantage over gastric tube for patients with imminent early mortality and those in a hospital. Subcutaneous infusions provide at least for a short time a suitable method for rehydration also and in particular for terminally ill patients. Peripheral venous catheters are suitable for rehydration, however only for a period of few days until another solution is found.

Catheterization, Peripheral↗

Coronary perfusion pressure, end-tidal CO2 and adrenergic agents in haemodynamic stable rats.

Coronary perfusion pressure (CPP) determines myocardial perfusion during low flow. CPP correlates with end-tidal CO2 (PetCO2) during cardiac arrest. Recent studies have demonstrated that after adrenaline, increased CPP was associated with decreased PetCO2. Intravenous infusions (4 min, N = 10) or bolus (10 s, N = 6) of methoxamine (60 micrograms/kg), isoproterenol (10 micrograms/kg), adrenaline and noradrenaline (3 micrograms/kg) were compared with saline placebo (0.2 ml/min) during spontaneous circulation in anaesthetized Sprague-Dawley rats. Infusion and bolus of methoxamine, adrenaline and noradrenaline increased CPP between 39 and 46% above baseline. Isoproterenol decreased CPP by 67%. PetCO2 decreased by 27% after bolus and only 10% after infusion of methoxamine but increased after infusion (7%) and bolus (10%) of isoproterenol and after infusion of adrenaline (11%) and noradrenaline (17%). Equipressor bolus of methoxamine, adrenaline and noradrenaline reduced PetCO2 between 10 and 27%. Bolus application induced more alpha-effects and drug infusion more beta-effects in the pulmonary vasculature. Thus, changes in pulmonary vascular resistance and associated increases in dead space were responsible for differences in PetCO2. Alpha-effects increased CPP, decreased P(et)CO2 and conversely, beta-effects decreased CPP but increased PetCO2 indicating caution when P(et)CO2 is used as non-invasive monitor of perfusion, especially after alpha-adrenergic agents.

Animals↗

[Polytrauma: comparison of the hospital course after air- (with emergency physician) versus ground transport (without emergency physician)].

We analyzed the influence of initial intensive care at the accident site performed by an emergency physician and followed by helicopter transport on the course during hospital stay in patients with multiple trauma. We therefore compared the dates of 107 patients transported by the swiss air rescue (REGA) and an emergency physician with 131 patients transported by an ambulance and paramedic staff. By similar case material the REGA-patients showed a higher injury severity grade. Mortality of the REGA-patients was significantly higher (21%) than of the ambulance-patients (10%), but length of stay was significantly shorter and morbidity identical. We suspect, that the higher mortality of the REGA-patients is explained by the large number of surgically nontreatable severe traumas. None of the REGA-patients arrived at hospital with circulatory insufficiency whereas 4 of the ambulance-patients were in state of shock. We assume that first of all primary treatment of the scene of injury by an emergency physician and eventually also transport by helicopter have a positive effect on the course of patients with multiple trauma during hospital stay.

Adult↗

[Development of the helicopter-rescue concept in the Basel region].

1927 medical helicopter transports were performed in Basle between 1986 and 1989. Of the total flights, 173 transports without patients and 186 incubator transports were excluded from the study. Treatment and transportation were provided for 1085 victims of trauma (70.2%) and 461 medical-surgical patients (29.8%), mostly with life-threatening conditions. 589 trauma patients were treated at the scene of accident and later transported by helicopter to a nearby medical center (54.3%). The 4.3% rate of negative emergency flights is low. Since introduction of the helicopter rescue system at Basle in 1975, scene flights have increased from 29% in 1984 to 46% in 1989. 47.4% of all patients were categorized as seriously ill or severely injured. 36.4% of all patients required intubation and assisted ventilation. Of the trauma patients, 54.3% involved scene-flights requiring in-field intensive therapy. Helicopter transport provides not only a rapid source of transportation, but also vital medical assistance at the scene of emergency. Transport generally occurs only after stabilization of vital functions. These factors contribute to the low mortality before return flights (3%) as well as during transport (0.3%). We conclude that early aggressive in-field intensive therapy can help to decrease both morbidity and mortality in emergency-care patients.

Aircraft↗

Survival in major burn injuries treated by one bathing in cerium nitrate.

Sixty-four patients aged 16-74 years with total body surface area burns (TBSA) ranging from 30 to 90 per cent, were given one bathing in 0.04 M cerium nitrate within 4 h of admission to hospital. Of 21 patients aged 16-30 years, one died (aged 28 with 90 per cent TBSA), and of those aged 31-74 years, two died, one (aged 50 years with 55 per cent TBSA) had multiple internal injuries, the other (aged 51 years with 55 per cent TBSA) had a pulmonary embolism at day 19. Two risk scores, developed from data on 11,200 burn patients treated by standard methods (Roi et al. 1983), were applied to the analysis of risk for 59 patients for whom both total burn surface (TB) and full thickness (FT) areas had been recorded. About 20 patients bore risk of 0.8 or greater on the FT scale and 1.0 on the TB scale, yet instead of 80 per cent deaths among these, only two died. No FT assessment had been made on the multiple injury death whose TB risk score was 0.66. Such survival results in high-risk patients should encourage the use of cerium nitrate for treating serious burn injury.

Adolescent↗

Perioperative myocardial ischemia in patients undergoing elective hip arthroplasty during lumbar regional anesthesia.

Perioperative myocardial ischemia predicts unfavorable outcomes and occurs in as many as 41% of patients with coronary artery disease or cardiac risk factors undergoing noncardiac surgery. To determine the prevalence of myocardial ischemia, we studied 52 consecutive unselected patients undergoing elective hip arthroplasty during lumbar regional anesthesia. Patients were continuously monitored for 6 days using a three-channel Holter monitor. Ninety-nine episodes of myocardial ischemia occurred in 16 patients (31%), six of whom were considered preoperatively to be at low risk for coronary artery disease. Forty-four percent of the ischemic episodes were preceded or accompanied by a heart rate greater than or equal to 100/min and 56% by a heart rate greater than or equal to 90 beats/min. Ninety-six percent of the ischemic episodes were clinically silent, and 82% were not related to patient care events. Thirteen episodes of myocardial ischemia occurred preoperatively, 1 intraoperatively, and 85 postoperatively. The incidence of postoperative ischemic episodes showed a circadian variation: 44% occurred between 6 AM and noon, 33% between noon and 6 PM, 17% between 6 PM and midnight, and 6% between midnight and 6 AM. Six adverse cardiac events occurred during hospitalization (three of the six among patients with perioperative ischemia) and an additional four events during a follow-up period of 12 months (all four events occurred among patients with perioperative ischemia). Patients with perioperative myocardial ischemia had a relative risk of 2.6 (95% confidence interval 1.3-5.2) to develop an adverse cardiac event postoperatively.

Aged↗

Adenosine during cardiac arrest and cardiopulmonary resuscitation: a placebo-controlled, randomized trial.

UNLABELLED: BACKGROUND AND HYPOTHESIS TESTED: The effects of adenosine (100 micrograms/kg/min; n = 7) were examined during rodent cardiopulmonary resuscitation (CPR). Change in coronary artery perfusion pressure, end-tidal PCO2, and arterial acid-base status of anesthetized, male, Sprague-Dawley rats were compared with CPR controls (0.9% sodium chloride; n = 7) and with sham controls (n = 9). Sustained ventricular fibrillation was induced and precordial chest compression was followed by defibrillation. RESULTS: After 6 mins of cardiac arrest, six (86%) of seven adenosine-treated animals were resuscitated after adenosine infusion and four (57%) of seven control animals were resuscitated after sodium chloride infusion. During chest compression, coronary artery perfusion pressure was 7 +/- 2 mm Hg after adenosine, but was 22 +/- 3 mm Hg in the controls (p less than .01). Parallel decreases were observed in mean aortic pressure. Arterial and end-tidal PCO2 significantly (p less than .01) decreased after adenosine. These changes contrasted with a second control group of nine identically prepared animals which, in the absence of ventricular fibrillation and subsequent chest compression, demonstrated no changes in hemodynamic, respiratory, or blood gas variables. CONCLUSIONS: Adenosine decreased coronary artery perfusion pressure. However, despite marked reductions in coronary artery perfusion pressure, survival was not compromised after adenosine infusion in this rodent model of CPR.

Acid-Base Equilibrium↗

Does on-scene resuscitation affect in-hospital "do not resuscitate" decisions and mortality in patients with severe head injuries?

To evaluate the effect of on-scene versus in-hospital resuscitation of patients with severe head injuries with regard to "do not resuscitate" (DNR) decisions and in-hospital mortality, 561 patients were prospectively studied. Patients were grouped according to whether resuscitation initially occurred at the scene of the injury (group 1), in a regional hospital before transfer (group 2), or after direct admission to our neurosurgical center (group 3). The DNR and mortality rates within the first 48 hours (13%, 10%, 10%, respectively) as well as for the entire stay in the surgical intensive care unit (SICU) were comparable for the three groups. It has been pointed out that efficient resuscitation at the scene of the injury may, instead of improving overall outcome, increase morbidity and mortality rates because more severely injured patients now reach the hospital alive. We conclude, however, that primary aggressive treatment at the scene of the injury did not increase DNR and in-hospital mortality rates within the 48-hour follow-up period, nor for the total stay in the SICU. Investigation of long-term outcome will be important to further establish the efficacy of this approach.

Adult↗

[Severe craniocerebral injuries: northwestern Switzerland 1984-1989].

Data from 561 severely head-injured patients treated in a Surgical Intensive Care Unit between 1984 and 1989 are analyzed. Age and sex distribution of the patients was comparable to findings in other studies. More than half of the patients were injured in road accidents, accidents involving cars representing the greatest risk. In 90% of all patients, severe head injury was the primary diagnosis. 60% of the patients were intubated within 30 minutes at the scene of the accident, as opposed to 17% of patients intubated in the emergency room within the same time interval. Patients resuscitated at the scene of the accident and admitted directly by helicopter arrived at the emergency room on average one hour after the accident; for those transported directly by ambulance, without intubation prior to admission, the average time interval was half an hour. Since the time interval between accident and onset of resuscitation is crucial, this difference in transportation times is not considered to be of major importance. Half of the patients who died in the Surgical Intensive Care Unit died within the first 48 hours, usually from primary severe brain damage. In 50% of the 446 patients from the first 4 years of this study the recoveries ranged from good to complete and 28% died. Only 3 (less than 1%) out of 446 patients were alive in a vegetative state, and 8% severely handicapped one year after the accident. Aggressive primary treatment did not increase the number of patients surviving in a vegetative or severely handicapped state.

Adolescent↗