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D V Tuxen

Publications and source records attributed to D V Tuxen.

At least 19 recordsLinked to original sources

Myopathy in severe asthma.

Myopathy complicating the therapy of severe asthma has been recently described in several case reports. Twenty-five consecutive patients admitted to the intensive care unit (ICU) at this hospital for mechanical ventilation for severe asthma were studied for the incidence of creatine kinase (CK) enzyme rise and for the development of clinical myopathy. Pharmacologic therapy was standardized, every patient receiving corticosteroids and aminophylline intravenously and salbutamol both nebulized and intravenously. Twenty-two patients received muscle relaxant therapy with vecuronium. In 19 of 25 (76%) of patients there was elevation of CK levels to a median of 1,575 U/L (range, 66 to 7,430) occurring 3.6 +/- 1.5 days after admission. In nine patients there was clinically detectable myopathy. The presence of either myopathy or CK enzyme rise was associated with a significant prolongation of ventilation time. Arterial blood gas measurements on admission to the ICU revealed a pH (mean +/- SD) of 7.07 +/- 0.21, a PaCO2 of 87.2 +/- 32.7, and a PaO2 (with a high FIO2) of 129 +/- 97 mm Hg; however, no correlation was found between the severity of initial metabolic disturbance and the subsequent development of myopathy. There was no association between the type of corticosteroid administered and the subsequent development of myopathy. Patients with myopathy had received a significantly higher total dose of vecuronium when compared with those who did not develop myopathy (p < 0.001, Kruskal Wallis test). We have therefore found a surprisingly high incidence of CK enzyme rise and myopathy in this group of mechanically ventilated patients with severe asthma.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Inhalation

Risk factors for morbidity in mechanically ventilated patients with acute severe asthma.

Acute severe asthma is associated with significant morbidity and mortality. We retrospectively quantified hypotension, pulmonary barotrauma, and cardiac arrhythmias in all patients with severe asthma admitted to the intensive care unit (ICU) and prospectively evaluated the predictive value of a measurement of dynamic hyperinflation (DHI) in those patients who required mechanical ventilation. In the first study, 88 ICU admissions for severe asthma over 5 yr (73 patients, 40 +/- 18 yr, 36 men, 37 women) were evaluated. Fifty-one admissions were mechanically ventilated, 29 were not, and 8 previously ventilated patients remained briefly intubated but were not ventilated in the ICU. Hypotension (18/88, 20%), pulmonary barotrauma (12/88, 14%), and arrhythmias (9/88, 10%) were entirely confined to patients who had been mechanically ventilated. There were no significant differences in ventilatory parameters, airway pressures, or blood gases between mechanically ventilated patients with and without complications. Two patients with previous severe hypoxic cerebral damage died from this complication after ICU discharge. In the second study, the end-inspiratory lung volume (VEI) (1) was compared with standard ventilatory parameters in 22 patients. There were no ICU deaths, but high incidences of pulmonary barotrauma (27%) and hypotension (41%) were found. Both minute ventilation (VE and VEI) were significantly higher in patients who developed complications (VE 13.7 +/- 3.0 versus 11.2 +/- 2.5 L/min, VEI 26.1 +/- 4.7 versus 20.0 +/- 7.4 ml/kg, p less than 0.05) but only VEI had a threshold value significantly predictive of complications. For VEI less than 1.4 L, 0/5 (0%) patients had complications; for VEI greater than or equal to 1.4 L, 11/17 (65%) had complications (p = 0.03).(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease

Use of a measurement of pulmonary hyperinflation to control the level of mechanical ventilation in patients with acute severe asthma.

Mechanical ventilation causes significant morbidity and mortality in patients with severe asthma. Hypoventilation may reduce this morbidity and mortality, but indicators to guide the degree of hypoventilation are unclear. We used a measure of pulmonary hyperinflation to assess the degree of airflow obstruction and to guide the extent and duration of hypoventilation. Ten patients who required mechanical ventilation for acute severe asthma were studied. All were sedated, paralyzed, and given an initial minute ventilation (VE) of 200 ml/kg/min. End-inspiratory lung volume (VEI) above FRC was measured from the total exhaled gas volume during 40 to 60 s of apnea. VEI was used to regulate VE to a safe level (VEsafe), irrespective of PaCO2, by reducing the rate when VEI was > 20 ml/kg and increasing it when VEI was < 20 ml/kg. Each patient was weaned when VEsafe resulted in PaCO2 < or = 40 mm Hg (the weaning point). FRC was measured computer analysis of anterior and lateral chest radiographs taken at the end of apnea. Using the weaning point criterion, 2 patients (PaCO2 < 40 mm Hg) were weaned shortly after arrival. The remaining eight (initial PaCO2, 63 +/- 17 mm Hg) continued hypoventilation until the weaning point was reached (30 +/- 29 h). The weaning point was reached by the VE required for PaCO2 40 mm Hg decreasing concurrent with the VEsafe increasing. All but 1 patient were successfully weaned within 24 h of the weaning point.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease

Fluid management of shock in critically-ill patients.

This article summarizes the theoretical basis and practical applications of the fluid management of shock in critically-ill patients. It also draws attention to the differences in the aetiology and management of fluid disturbances in adult and paediatric practice. Some evidence suggests that colloidal solutions alone may be superior to crystalloid solutions alone in the resuscitation of patients with shock, but in most situations a combination of both types of fluid is more logical.

Adult

Effects of gastric alkalization on bacterial colonization in critically ill patients.

Gastric alkalization of critically ill patients is associated with bacterial and fungal overgrowth in gastric contents. We studied the incidence of gastric colonization and its relation to other infections and antibiotic therapy in 25 critically ill ICU patients. All patients received 12-h NG Mylanta II and 15 received an H2-receptor antagonist. All patients had bacterial colonization of NG contents within 4 days of ICU admission and 10 had Candida colonization within 8 days. There were 70 NG isolates and the same isolates were found in tracheobronchial secretions (n = 46), blood (n = 4), urine (n = 4), and wounds (n = 8). Tracheobronchial colonization was preceded by NG colonization with the same organism in 12 instances (11 patients), was concurrent with NG colonization in 20 instances (14 patients), was followed by NG colonization in 14 instances (11 patients), and had no similar NG isolate in 18 instances (11 patients). NG culture of the same organism preceded four of eight positive blood cultures. In 35 of 70 NG isolates and five of 11 subsequent tracheobronchial isolates, colonization occurred despite concurrent appropriate antibiotics. We conclude that colonization of alkalinized NG contents is universal, is a common source of infection in other areas, and is not prevented by systemic antibiotic therapy. Local antibiotic therapy may be important in controlling this important source of infection.

Adult

Whole lung pulmonary angiography in the intensive care unit with two portable chest x-rays.

Suspected massive pulmonary embolism requires urgent, accurate diagnosis. We describe a technique for pulmonary angiography in the ICU. Four patients admitted with suspected pulmonary embolism had fulminating cardiorespiratory failure with support requirements precluding transfer. Each patient had a flow-directed pulmonary angiography catheter inserted into the pulmonary artery. In two catheter positions, 25 ml of iopamidol 612 mg/ml was delivered from a portable angiographic injector at a flow of 20 ml/sec. A portable x-ray was taken immediately before completion of syringe excursion. Major central pulmonary emboli were seen in three patients and a negative angiogram was obtained on the fourth. Two of the three positive diagnoses were confirmed at pulmonary embolectomy. The negative diagnosis was confirmed at autopsy. Pulmonary angiography via a flow-directed catheter enabled precise and rapid diagnosis of pulmonary embolism in patients too ill to transfer for formal angiography.

Adult

Detrimental effects of positive end-expiratory pressure during controlled mechanical ventilation of patients with severe airflow obstruction.

Positive end-expiratory pressure (PEEP) in treatment of asthma may be beneficial by dilating airways or detrimental by increasing hyperinflation. Several studies have reported beneficial results but with conflicting effects on lung volume. We studied the effects of PEEP on pulmonary hyperinflation, gas exchange, and circulation in six patients (59 +/- 19 yr, four men, two women) with severe airflow obstruction requiring mechanical ventilation (four with asthma, two with an exacerbation of chronic airflow obstruction). Three levels of PEEP (5, 10, and 15 cm H2O) were studied. All patients were paralyzed and ventilated with a tidal volume of 1.0 L, and respiratory rates (R) of 10, 16, and 22 breaths per min. End-inspiratory lung volume (VEI) or the degree of pulmonary hyperinflation above functional residual capacity (FRC) was quantified by measuring total exhaled gas volume during a period of apnea following steady-state tidal inspiration (1). Two patients were not studied at 15 cm H2O PEEP because of hypotension. Without PEEP, all patients showed gas trapping above FRC that increased progressively as R was increased (i.e., expiratory time decreased). At each R, increases in PEEP progressively increased FRC up to 1.42 +/- 0.43 L (mean +/- SD) at 15 cm H2O PEEP (n = 4) and progressively reduced the degree of gas trapping above the PEEP FRC.(ABSTRACT TRUNCATED AT 250 WORDS)

Airway Obstruction

Prevention of lower respiratory herpes simplex virus infection with acyclovir in patients with the adult respiratory distress syndrome.

Herpes simplex virus (HSV) type I commonly occurs in the lower respiratory tract (LRT) of seriously ill patients, particularly those with the adult respiratory distress syndrome (ARDS), but it is not known whether HSV is a benign mucosal colonizer or a pathogen. The aims of this study were to determine whether the antiviral agent acyclovir could prevent this occurrence, and if so, whether prevention improved the outcome. Forty-five patients with ARDS underwent double-blind randomization into a treatment group (22 subjects) who received prophylactic acyclovir intravenously, 5 mg/kg every 8 h, and a control group (23 subjects). Upper and lower respiratory secretions were examined for the presence of HSV before randomization and twice weekly thereafter. Seven patients were excluded because of HSV detection prior to treatment. There were no significant differences between the remaining 17 acyclovir and 21 control patients in age, sex, distribution of primary diagnostic categories, and severity of primary illness. Only 1 patient (6%) in the acyclovir group developed HSV after treatment compared with 15 (71%) in the control group (p less than 0.001), but there was no improvement in the acyclovir group in the severity of respiratory failure, the duration of ventilator support (acyclovir, 20 +/- 19 days; control, 14 +/- 11 days), or mortality (acyclovir, 8 of 17, 47%; control, 9 of 21, 43%). We conclude that acyclovir is effective in preventing the high incidence of HSV in patients with ARDS, but that this prevention does not improve outcome. Routine prophylaxis of HSV is not recommended.

Acyclovir

The effects of ventilatory pattern on hyperinflation, airway pressures, and circulation in mechanical ventilation of patients with severe air-flow obstruction.

Patients with severe air-flow obstruction receiving mechanical ventilation are at risk of inadvertent pulmonary hyperinflation with morbidity and mortality caused by pneumothorax and circulatory depression. Nine patients with severe air-flow obstruction (5 asthma, 4 chronic air-flow obstruction) requiring mechanical ventilation were studied while sedated and therapeutically paralyzed. Pulmonary hyperinflation during steady-state ventilation was quantified by measuring total exhaled volume during 20- to 40-s apnea (end-inspiratory lung volume, VEI). Patients were studied at 3 levels of minute ventilation (VE) (10, 16, and 26 L/min) and at each VE, 3 levels of tidal volume (VT) (0.6, 1.0, and 1.6 L) and 3 levels of inspiratory flow (VI) (40, 70, and 100 L/min for VT = 1.0 L). There were progressive increases in VEI when VT was increased or when expiratory time (TE) was decreased either by an increase in rate (and hence VE) or by a decrease in VI (at a constant VE) reaching lung volumes as high as 3.6 +/- 0.4 L above FRC. Alveolar, central venous, and esophageal pressure rose in parallel with lung volumes, and hypotension was seen in most patients at highest lung volumes. Peak airway pressure (Ppk) was predominantly related to inspiratory flow and did not reflect changes in lung volume. Levels of ventilation required for normocapnia prior to paralysis (15.7 +/- 2.3 L/min) were associated with hypotension in 7 patients and probable hyperinflation in excess of 1.96 +/- 0.17 L above FRC. VEI is a simple, reproducible measurement of pulmonary hyperinflation and may be more important than Ppk in the causation of barotrauma.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease