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Biomedical subjects

D V Tuxen

Publications and source records attributed to D V Tuxen.

At least 19 recordsLinked to original sources

Hyperbaric or normobaric oxygen for acute carbon monoxide poisoning: a randomised controlled clinical trial.

OBJECTIVE: To assess neurological sequelae in patients with all grades of carbon monoxide (CO) poisoning after treatment with hyperbaric oxygen (HBO) and normobaric oxygen (NBO). DESIGN: Randomised controlled double-blind trial, including an extended series of neuropsychological tests and sham treatments in a multiplace hyperbaric chamber for patients treated with NBO. SETTING: The multiplace hyperbaric chamber at the Alfred Hospital, a university-attached quarternary referral centre in Melbourne providing the only hyperbaric service in the State of Victoria. PATIENTS: All patients referred with CO poisoning between 1 September 1993 and 30 December 1995, irrespective of severity of poisoning. Pregnant women, children, burns victims and those refusing consent were excluded. INTERVENTION: Daily 100-minute treatments with 100% oxygen in a hyperbaric chamber--60 minutes at 2.8 atmospheres absolute for the HBO group and at 1.0 atmosphere absolute for the NBO group--for three days (or for six days for patients who were clinically abnormal or had poor neuropsychological outcome after three treatments). Both groups received continuous high flow oxygen between treatments. MAIN OUTCOME MEASURES: Neuropsychological performance at completion of treatment, and at one month where possible. RESULTS: More patients in the HBO group required additional treatments (28% v. 15%, P = 0.01 for all patients; 35% v. 13%, P = 0.001 for severely poisoned patients). HBO patients had a worse outcome in the learning test at completion of treatment (P = 0.01 for all patients; P = 0.005 for severely poisoned patients) and a greater number of abnormal test results at completion of treatment (P = 0.02 for all patients; P = 0.008 for severely poisoned patients). A greater percentage of severely poisoned patients in the HBO group had a poor outcome at completion of treatment (P = 0.03). Delayed neurological sequelae were restricted to HBO patients (P = 0.03). No outcome measure was worse in the NBO group. CONCLUSION: In this trial, in which both groups received high doses of oxygen, HBO therapy did not benefit, and may have worsened, the outcome. We cannot recommend its use in CO poisoning.

Adult

Optimal assessment of cervical spine trauma in critically ill patients: a prospective evaluation.

There is no uniformly accepted protocol for the radiological assessment of the cervical spine in critically ill trauma patients. The Alfred Trauma Centre receives about 40% of Victorian patients with major trauma. A protocol was developed for cervical spine evaluation, comprising three plain X-rays and a swimmer's view added when necessary to visualize C7-T1, CT and/or MRI for abnormal regions, and functional (flexion/extension) X-rays to exclude cervical spine instability due to soft tissue trauma. Functional X-rays were performed "actively" in conscious patients and "passively" in unconscious patients. One hundred consecutive patients were prospectively evaluated and 91 survived to complete data collection. Six (6.6%) had unstable cervical spine injuries--five detected with plain X-rays and one (1.1%) detected only with passive functional X-rays. Static cervical X-rays cost $93.00 per patient. Functional cervical X-rays added $42.00 per patient and were uncomplicated. Collar complications were common when collars remained on for more than 72 hours. This low detection rate is clinically important because of the enormous potential social and economic costs of missed unstable cervical spine fractures.

Adult

Acute weakness syndromes in critically ill patients--a reappraisal.

Over the last twenty years, increasing numbers of critically ill, mechanically ventilated patients who develop acute profound muscle weakness have been described. These acute weakness syndromes have not been well understood and they have been given many names including: acute steroid myopathy, acute quadriplegic myopathy, the floppy person syndrome, critical illness polyneuropathy, critical illness polyneuromyopathy, and prolonged neurogenic weakness. Many of these "syndromes" either overlap or represent the same disease process in different patients. Many have been incompletely diagnosed. During this review it became evident that the acute weakness syndromes currently recognized in critically ill patients could be categorized into four major groups: myopathy, neuromuscular junction abnormalities, neuropathy and polyneuromyopathy. Each had different possible aetiologies. "Myopathy" includes acute necrotizing myopathy and disuse atrophy. Neuromuscular junction abnormalities are subdivided into myasthenia-like syndromes and prolonged neuromuscular blockade. Neuropathies are divided into critical illness polyneuropathy and acute motor neuropathy. The anterior horn cell injury in Hopkins syndrome should also be considered in this group. Polyneuromyopathies include various combinations of neuropathy and myopathy in the same patients.

Acute Disease

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