Effects of low phosphorus supply on the availability of calcium and phosphorus, and musculoskeletal development of growing dogs of two different breeds.

To investigate the impact of a selective reduction in dietary phosphorus (P) supply on healthy growing dogs, a total of 23 Beagles and 30 Foxhound crossbreds (FBI) were used in a feeding trial between 6 and 24 weeks of age. Sixteen Beagles and 19 FBI were fed with selectively reduced P concentrations (low phosphorus, LP). The remaining puppies received a completely balanced control diet (CON). With these diets, the P supply in the Beagles at the age of 12 weeks added up to 2.5 ± 0.6 (LP) and 9.8 ± 1.4 g P/kg DM (CON), and in the FBI 4.3 ± 0.9 (LP) and 13.0 ± 1.6 g P/kg DM (CON). Therefore, the LP Beagles received an average of 33 ± 11% of the recommended daily allowances (RDA) of P, the LP FBI 41 ± 11%. The calcium (Ca) concentration stayed unaltered and led to a Ca/P ratio above the recommended range of 1.3/1 to 2/1. The apparent digestibility (aD) of phosphorus was reduced in the LP Beagle; otherwise, the aD of both minerals was not affected by the P concentration of the diet. The renal excretion of P was reduced to zero in both LP groups while the renal calcium excretion increased significantly. Several of the puppies from both breeds showed impaired appetite, growth, skin and fur quality, and a few also clinically showed relevant signs of a disturbed musculoskeletal system after the LP feeding. A rapid loss of muscle strength and posture within hours led to severe deviation of the limb axis with hyperflexion of the joints but no radiological aberrations or signs of pain. Immediate transition of affected puppies to a balanced diet with sufficient phosphorus resulted in a complete recovery of the puppies in less than one month. The results demonstrate the importance of an adequate P supply on the healthy development of growing dogs.

Acute abdominal compartment syndrome: current diagnostic and therapeutic options.

BACKGROUND: If untreated, the abdominal compartment syndrome (ACS) has a mortality of nearly 100 %. Thus, its early recognition is of major importance for daily rounds on surgical intensive care units. Intraabdominal hypertension (IAH) is a poorly recognized entity, which occurs if intraabdominal pressure arises >12 mmHg. Measurement of the intravesical pressure is the gold standard to diagnose IAH, which can be detected in about one fourth of surgical intensive care patients. PURPOSE: The aim of this manuscript is to outline the current diagnostic and therapeutic options for IAH and ACS. While diagnosis of IAH and ACS strongly depends on clinical experience, new diagnostic markers could play an important role in the future. Therapy of IAH/ACS consists of five treatment "columns": intraluminal evacuation, intraabdominal evacuation, improvement of abdominal wall compliance, fluid management, and improved organ perfusion. If conservative therapy fails, emergency laparotomy is the most effective therapeutic approach to achieve abdominal decompression. Thereafter, patients with an open abdomen require intensive care and are permanently threatened by the quadrangle of fluid loss, muscle proteolysis, heat loss, and an impaired immune function. As a consequence, complication rate dramatically increases after 8 days of open abdomen therapy. CONCLUSION: Despite many efforts, the mortality of patients with ACS remains unacceptably high. Permanent clinical education and surgical trials will be necessary to improve the outcome of our critically ill surgical patients.

The impact of early surgical intervention in free intestinal perforation: a time-to-intervention pilot study.

PURPOSES: An abdominal inflammatory focus is the second most often source of sepsis with a high risk of death in surgical intensive care units. By establishing evidence-based bundled strategies the surviving sepsis campaign provided an optimized rapid and continuous treatment of these emergency patients. Hereby the hospital mortality decreased from 35 to 30 %. Sepsis treatment is based on three major therapeutic elements: surgical treatment (source control), antiinfective treatment, and supportive care. The international guidelines of the surviving sepsis campaign were updated recently and recommend rapid diagnosis of the infection and source control within the first 12 h after the diagnosis (grade 1c). Interestingly this recommendation is mainly based on studies on soft tissue infections. METHODS: In this retrospective analysis 76 septic patients with an intraabdominal inflammatory focus were included. All patients underwent surgery at different time-points after diagnosis. RESULTS: With 80 % patients of the early intervention group had an improved overall survival (vs. 73 % in the late intervention group). CONCLUSIONS: Literature on the time dependency of early source control is rare and in part contradicting. Results of this pilot study reveal that immediate surgical intervention might be of advantage for septic emergency patients. Further multi-center approaches will be necessary to evaluate, whether the TTI has any impact on the outcome of septic patients with intestinal perforation.

[Diagnosis and therapy of an acute abdomen]. / Diagnostik und Therapie des akuten Abdomens.

Patients with signs of an acute abdomen continue to be a challenge for both the emergency physician and the intensivist. Clinical symptoms usually result from secondary peritonitis possibly progressing to intraabdominal sepsis. Critically ill patients need rapid diagnostic work-up and an interdisciplinary therapeutic approach. Among patients with secondary peritonitis, those with postoperative peritonitis (e.g., after anastomotic leakage) show a particularly high mortality because of unspecific symptoms. Beyond routine diagnostic procedures, patients with an acute abdomen often require a CT scan which helps to detect the septic focus, thereby often allowing an interventional source control. Therapy consists of three main elements: source control, broad-spectrum antimicrobial therapy, and supportive intensive care medicine.

Regional blood volume distribution during positive and negative airway pressure breathing in supine humans.

To assess the effects of continuous positive (CPAP) or negative airway pressure (CNAP) breathing (+/- 10-12 cmH2O, duration 25 min) on blood content in the body's capacitance vasculature, regional distribution of labeled red blood cells was evaluated in seven spontaneously breathing supine volunteers. Counts were acquired by whole body scans and detectors overlying the liver, intestine, left ventricle, and lower arm, and arterial pressure, heart rate, calf blood flow and vascular resistance, hematocrit, vasopressin, and atrial natriuretic peptide plasma concentrations were also obtained. With CPAP, thoracic, cardiac, and left ventricular counts diminished significantly by 7-10%, were accompanied by significant increases in counts over both the gut and liver, and remained decreased during CPAP but reversed to baseline with zero airway pressure. Calf blood flow and vascular resistance significantly decreased and increased, respectively, whereas limb counts, arterial pressure, heart rate, and hormone concentrations remained unchanged. With CNAP, in contrast, regional counts and other variables did not change. Thus, moderate levels of CPAP deplete the intrathoracic vascular bed and heart, shifting blood toward the gut and liver but not toward the limbs. No short-term compensation increasing cardiac filling during CPAP was seen. In contrast, CNAP did not alter intrathoracic or organ blood content and, therefore, does not simply mirror the effects evoked by CPAP.

A comparison of two pulmonary artery mixed venous oxygen saturation catheters during the changing conditions of cardiac surgery.

Continuous mixed venous oxygen saturation (SvO2), using modified pulmonary artery (PA) catheters, can assist in the management of cardiac surgery patients. Two FDA-approved catheters are available for SvO2 monitoring. One system uses two wavelengths of light and the other is a three-wavelength system. The present study was designed to determine the accuracy of the two catheters during cardiac surgery. Sixty-five consecutive patients were assigned to one of the two catheter groups. Data were collected pre- and post-induction, after sternotomy, and after extracorporeal circulation. An updated hematocrit was entered in the two-wavelength system preceding the last two measurements. Patient demographics, severity of preoperative cardiac disease, and intraoperative hemodynamics were comparable between groups. Two-wavelength determinations varied inconsistently from cooximeter values, while three-wavelength measurements did not differ significantly. Changes in hematocrit were responsible in part for the variability in two-wavelength measurements. In summary, three-wavelength measurements by the Shaw system were more accurate than two-wavelength measurements by the Edwards system.

Effect of intercostal nerve blockade on respiratory mechanics and CO2 chemosensitivity at rest and exercise.

Lower intercostal and abdominal muscles interact with other respiratory muscles to produce inspiration as well as expiration. Intercostal nerve blockade from T6-T12 was produced in seven healthy males to study its effect on: 1) supine pulmonary function, 2) inspiratory effort, 3) hypercapnic ventilatory response, including mouth occlusion pressures with and without an expiratory load, and 4) ventilation during progressive exercise on a cycle ergometer. Studies during control and blocked states were performed on different days. Lower chest and abdominal wall paralysis was documented with electromyography. Findings include a minimal decrease in peak expiratory flows with intercostal blockade (P = 0.02), but no other changes in supine resting pulmonary function tests, inspiratory effort, or hypercapnic ventilatory response slopes. Minute ventilation, respiratory rate, and VT/TI during exercise were also minimally increased, indicating an increase in the drive to breathe, which was unrelated to a change in metabolic rate. During exercise, total time to exhaustion was decreased following intercostal nerve blockade. Bilateral intercostal nerve blockade produced minimal decreases in peak expiratory flow at rest in supine subjects. During seated exercise, there was a slight increase in respiratory drive, probably due to minor alterations in the mechanics of breathing induced by intercostal blockade. The authors conclude that, in healthy young subjects, intercostal nerve blockade does not exert a clinically significant adverse affect on pulmonary mechanics and that ventilatory function is well-maintained even at extremes of ventilatory demand.

Pulmonary oedema following airway obstruction in a patient with Hodgkin's disease.

We report a case of pulmonary oedema following airway obstruction in a patient who underwent biopsy of a tumour involving the anterior mediastinum and neck. The occurrence of airway obstruction in patients with anterior mediastinal masses, and the pathogenesis of pulmonary oedema occurring in association with airway obstruction, are discussed.

Analgetic contribution of sufentanil during halothane anesthesia: a mechanism involving serotonin.

Catecholamine and serotonin concentrations in the cord, medulla, and hypothalamus were measured in rats after saline, after sufentanil sufficient to reduce the minimum alveolar concentration (MAC) of halothane by 30% or less, or after sufentanil sufficient to reduce the MAC of halothane by 80% or more. In the cord, high doses of sufentanil resulted in a 13.4% reduction (P less than 0.05) in serotonin concentration compared to saline control and a 17.4% reduction (P less than 0.05) in serotonin concentration compared to low dosages of sufentanil. A 12.8% reduction (P less than 0.05) in medullary serotonin also was observed with high sufentanil compared to low sufentanil. Epinephrine decreased significantly in the hypothalamus at the high sufentanil dose. No other significant differences were found in catecholamine content. The experimental results support the hypothesis that sufentanil may contribute to an analgetic component of general anesthesia by modulating nociception via the release of 5-HT.

Pulsed galvanic stimulation: effects of current frequency and polarity on blood flow in healthy subjects.

The effects of pulsed galvanic stimulation on peripheral blood flow were studied in ten healthy volunteers. Electrodes were placed over vascular channels of the upper extremity and stimulation was carried out at several frequencies on two occasions with polarity reversed. Changes in blood flow and cutaneous temperature were measured by photoplethysmography and cutaneous thermistors, respectively. A trend toward greater blood flow was seen at the highest frequencies and negative polarity. There were no significant temperature variations from baseline with any frequencies. This study suggests that, based on clinical evidence, able-bodied volunteers may vary in response from patients with vasospastic disorders.

Influence of magnesium ion on human ventricular defibrillation after aortocoronary bypass surgery.

The administration of magnesium ion (Mg++) has been reported to defibrillate the ventricles and to decrease the incidence of arrhythmias after cardiopulmonary bypass. In a prospective study of 76 randomly selected patients undergoing coronary artery bypass grafting, patients received either no Mg++, 0.25 mEq/kg of Mg++ during cardiopulmonary bypass with the aorta clamped, or 0.375 mEq/kg of Mg++ before cardiopulmonary bypass. Spontaneous resumption of a cardiac rhythm or spontaneous defibrillation during reperfusion was not significantly affected by Mg++ administration. However, the number of shocks to initial and to sustained defibrillation and the energy required for the last direct-current shock was greatest in patients who received Mg++ before bypass and in those whose plasma Mg++ was greater than 2.26 mg/dl. Thus, the administration of Mg++ may have adverse effects on the heart if intraoperative plasma Mg++ exceeds 2.26 mg/dl.

Biological communities at the Florida escarpment resemble hydrothermal vent taxa.

Dense biological communities of large epifaunal taxa similar to those found along ridge crest vents at the East Pacific Rise were discovered in the abyssal Gulf of Mexico. These assemblages occur on a passive continental margin at the base of the Florida Escarpment, the interface between the relatively impermeable hemipelagic clays of the distal Mississippi Fan and the jointed Cretaceous limestone of the Florida Platform. The fauna apparently is nourished by sulfide rich hypersaline waters seeping out at near ambient temperatures onto the sea floor.

The decrease of the minimum alveolar anesthetic concentration produced by sufentanil in rats.

The anesthetic potency of sufentanil was established by determining its effect on the minimal alveolar anesthetic concentration (MAC) of halothane. Each of eight selected doses of sufentanil was administered to a group of four to five mechanically ventilated rats anesthetized with halothane. Sufentanil was administered as a constant infusion preceded by an intravenous bolus dose that was three times that of the infusion rate per minute. The tail-clamp technique was used to establish control MAC and the MAC of halothane with sufentanil. Increasing sufentanil dosages were nonlinearly related to reductions in the MAC of halothane. A sigmoidal dose-response curve was described. An abrupt, steep response follows the initial upward deflection of the curve with an additional 62% MAC reduction occurring between doses of 1 X 10(-5) mg X kg-1 X min-1 and 1 X 10(-4) mg X kg-1 X min-1. Essentially complete anesthesia was seen at the latter dosage. No significant adverse side effects were seen with sufentanil at doses up to 1 X 10(-2) mg X kg-1 X min-1.

Intraoperative diagnosis and treatment of massive pulmonary embolism complicating surgery on the abdominal aorta.

Massive pulmonary embolism associated with total cardiovascular collapse occurred during the surgical repair of a ruptured abdominal aortic aneurysm with an aortocaval fistula. Pulmonary artery pressure monitoring permitted immediate diagnosis whereas central venous pressures did not reflect the obstruction to right ventricular outflow. Pulmonary embolectomy without cardiopulmonary bypass was performed successfully.

Psychosocial function in women treated for vaginal agenesis.

The psychosocial functioning of 23 women treated both surgically and nonsurgically for vaginal agenesis was assessed by means of a retrospective questionnaire. Subjects were also physically examined to evaluate anatomic outcome. It was concluded that the patients psychological adjustment before treatment and the sensitivity of her family and medical advisors during treatment took precedence over anatomic results in the eventual resolution of this disorder. Sexual function, emotional stability, self-image, and choice of marital partner in these women are described in some detail and are, in general, far healthier than had been depicted in earlier psychological reports.