Initial administration of hydroxyethyl starch vs lactated Ringer after liver trauma in the pig.

BACKGROUND: This study tested the circulatory effectiveness of post-trauma administration of a large intravascular volume expander, hydroxyethyl starch 130/0.4 (HES), vs standard lactated Ringer's solution (RL). METHODS: Liver injury was inflicted in 14 pigs [31 (4) kg; mean (sd)] and treatment simulated an acute pre-hospital event: after a standard first-respond delay (7 min), volume administration was provided in three phases to simulate increasing intravascular access. In the first two phases, the fluid was administered either by HES or by RL and, during the last phase, all animals received HES to stabilize the intravascular volume. RESULTS: The liver trauma severed an equal number of 1-3 mm diameter blood vessels [1.4 (0.6)] and after 7 min, the blood loss was 184 (127) ml and mean arterial pressure had decreased by 19 (13) mm Hg (P<0.01). The intravascular volume expansion effect was 115 (25)% for HES and 76 (21)% for RL (P<0.05), yet oxygen uptake was maintained in zero of seven vs three of seven pigs and the survival was three of seven vs seven of seven, respectively (P<0.05). In these animals, the initial administration of HES provoked uncontrolled bleeding, whereas the administration of RL was associated with attenuated bleeding: total blood loss 2455 (1919) vs 311 (208) ml, respectively (P<0.01), reflecting that bleeding ceased in six of the pigs administered RL. CONCLUSIONS: After injury, the intravascular volume expanding effect of HES was larger than that for RL. However, initial administration of HES provoked uncontrolled haemorrhage, suggesting that prioritizing intravascular volume expansion did not result in stabilization of the circulation after haemorrhage.

Venous oxygen saturation during normovolaemic haemodilution in the pig.

BACKGROUND: Hypovolaemia may be considered to represent a volume-restricted cardiac output (CO), but CO varies inversely with the haemoglobin concentration (Hb) and a maximal mixed venous oxygen saturation (SvO2) may be a better target for volume administration than a maximal CO. METHODS: In 10 anaesthetized pigs, volume loading with 6% hydroxyethyl starch was performed to obtain a maximal SvO2 followed by normovolaemic haemodilution with 6% hydroxyethyl starch. RESULTS: Volume loading increased SvO2 from 55.0+/-5.2% to 64.8+/-9.0% (mean+/-SD) associated with an increase in CO (2.3+/-0.4 to 3.5+/-0.9 l/min) and central venous oxygen saturation (ScvO2; 68.2+/-9.3% to 79.4+/-7.2%; P<0.05). Heart rate (HR), mean arterial (MAP), central venous (CVP), pulmonary arterial mean (PAMP), and occlusion pressures (PAOP) increased as well (P<0.05). In contrast, during progressive haemodilution, SvO2 and ScvO2 remained statistically unchanged until the haemoglobin concentration had decreased from 5.5+/-0.4 to 2.9+/-0.2 mM, while CO and HR increased at a haemoglobin value of 4.4+/-0.4 and 4.0+/-0.4 mM and CVP and PAOP decreased at a haemoglobin of 4.0+/-0.4 and 2.9+/-0.2 mM, respectively (P<0.05) leaving MAP unaffected. CONCLUSION: This study found that volume loading increased cardiac output and mixed and central venous oxygen saturations in parallel, but during normovolaemic haemodilution an increase in cardiac output left mixed and central venous oxygen saturations statistically unchanged until haemoglobin concentration was reduced by approximately 50%. Accordingly, volume therapy should be directed to maintain a high venous oxygen saturation rather than a change in cardiac output.

Variable pulmonary responses from exposure to concentrated ambient air particles in a rat model of bronchitis.

Chronic bronchitis may be considered a risk factor in particulate matter (PM)-induced morbidity. We hypothesized that a rat model of human bronchitis would be more susceptible to the pulmonary effects of concentrated ambient particles (CAPs) from Research Triangle Park, NC. Bronchitis was induced in male Sprague-Dawley rats (90-100 days of age) by exposure to 200 ppm sulfur dioxide (SO2), 6 h/day x 5 days/week x 6 weeks. One day following the last SO2 exposure, both healthy (air-exposed) and bronchitic (SO2-exposed) rats were exposed to filtered air (three healthy; four bronchitic) or CAPs (five healthy; four bronchitic) by whole-body inhalation, 6 h/day x 2 or 3 days. Pulmonary injury was determined either immediately (0h) or 18 h following final CAPs exposure. The study protocol involving 0 h time point was repeated four times (study #A, November, 1997; #B, February, 1998; #C and #D, May, 1998), whereas the study protocol involving 18 h time point was done only once (#F). In an additional study (#E), rats were exposed to residual oil fly ash (ROFA), approximately 1 mg/ m(3)x6 h/day x 3 days to mimic the CAPs protocol (February, 1998). The rats allowed 18 h recovery following CAPs exposure (#F) did not depict any CAPs-related differences in bronchoalveolar lavage fluid (BALF) injury markers. Of the four CAPs studies conducted (0 h time point), the first (#A) study (approximately 650 microg/m3 CAPs) revealed significant changes in the lungs of CAPs-exposed bronchitic rats compared to the clean air controls. These rats had increased BALF protein, albumin, N-acetyl glutaminidase (NAG) activity and neutrophils. The second (#B) study (approximately 475 microg/m3 CAPs) did not reveal any significant effects of CAPs on BALF parameters. Study protocols #C (approximately 869 microg/m3 CAPs) and #D (approximately 907 microg/m3 CAPs) revealed only moderate increases in the above mentioned BALF parameters in bronchitic rats exposed to CAPs. Pulmonary histologic evaluation of studies #A, #C, #D, and #F revealed marginally higher congestion and perivascular cellularity in CAPs-exposed bronchitic rats. Healthy and bronchitic rats exposed to ROFA (approximately 1 mg/m3) did not show significant pulmonary injury (#E). Analysis of leachable elemental components of CAPs revealed the presence of sulfur, zinc, manganese, and iron. There was an apparent lack of association between pulmonary injury and CAPs concentration, or its leachable sulfate or elemental content. In summary, real-time atmospheric PM may result in pulmonary injury, particularly in susceptible models. However, the variability observed in pulmonary responses to CAPs emphasizes the need to conduct repeated studies, perhaps in relation to the season, as composition of CAPs may vary. Additionally, potential variability in pathology of induced bronchitis or other lung disease may decrease the ability to distinguish toxic injury due to PM.

Accurate monitoring of blood loss: thoracic electrical impedance during hemorrhage in the pig.

BACKGROUND: Cardiovascular variables are closely regulated in that they remain relatively stable during minor hemorrhage. We considered that such stability would make these variables less accurate for monitoring a blood loss. In contrast, thoracic electrical impedance would be unlikely to be a regulated variable and could serve as a non-invasive monitor of a volume deficit. METHODS: In 10 pigs bled (0-24 ml kg(-1)) and retransfused (to 28 ml kg(-1)) during halothane anesthesia, the magnitude of the electrical impedance, cardiovascular, blood gas and temperature variables, atrial natriuretic peptide and near infrared spectroscopy of the leg muscles were recorded. RESULTS: During hemorrhage and retransfusion, the median correlations between changes in the magnitude of the thoracic impedance and the external blood loss ranged from 0.97 to 0.98 with an individual range from 0.80 to 1.0. These correlation coefficients were higher and their ranges were lower than correlations established for any other measured parameter. CONCLUSION: During hemorrhage and retransfusion in the halothane anesthetized pig, a change in the magnitude of thoracic electrical impedance appears to be an accurate and also non-invasive monitor of a blood volume deficit.

Central cardiovascular and oxygen variables during haemorrhage in the pig.

BACKGROUND: We evaluated the ability of the standards issued by the Danish Society of Anaesthesiologists to reflect a blood loss. METHODS: In 9 pigs bled (0-24 ml kg-1 and retransfused (to 28 ml kg-1) during halothane anaesthesia central cardiovascular, thoracic electrical impedance (TI), oxygen, acid-base and temperature variables were recorded. RESULTS: With the recommendation for minor surgery (mean arterial pressure (MAP) and heart rate (HR)), the correlation to the blood loss was 0.74 (P < 0.001) and with that for major surgery (MAP, HR, central venous pressure (CVP) and rectal temperature (Tempr)) it was 0.79 (P < 0.001). With the recommendation for extensive surgery (MAP, HR, CVP, pulmonary artery catheter variables and the central-peripheral temperature difference (delta Tempr-t)), the correlation was 0.84 (P < 0.001). Non-invasive monitoring (MAP, HR, delta Tempr-t, TI and near-infrared spectroscopy of the brain (SinvosO2)) was only slightly better than basal monitoring (r = 0.76, P < 0.001). However, adding arterial base excess (BE), TI, and peripheral temperature (Tempt) to the recommendation for major surgery resulted in a correlation of 0.87 (P < 0.001), while adding BE and TI to the recommendation for extensive surgery raised correlation to only 0.88 (P < 0.001). CONCLUSION: When the recommendations were followed the correlation to the blood loss ranged from 0.74-0.84. However, with the recording of MAP, HR, CVP, delta Tempr-t, BE and TI a correlation of 0.87 was achieved, indicating that a pulmonary artery catheter may not be in need for patients undergoing surgical procedures with expected haemorrhage.

Trichinella infection and clinical disease.

Trichinellosis is caused by ingestion of insufficiently cooked meat contaminated with infective larvae of Trichinella species. The clinical course is highly variable, ranging from no apparent infection to severe and even fatal disease. We report two illustrative cases of trichinellosis. Returning to Denmark a few days after having eaten roasted pork in the Republic of Serbia, a female patient suffered from severe vomiting, epigastric pain, diarrhoea, and later myalgia, arthralgia, generalized oedema, and prostration. A biopsy showed heavy infestation with Trichinella spiralis, 2000 larvae/g of muscle. Life-threatening cardiopulmonary, renal and central nervous system complications developed. The patient recovered after several months. Her husband, who also ate the pork, did not have clinical symptoms, but an increased eosinophil count and a single larva in a muscle biopsy confirmed infection. The epidemiology, clinical manifestations, diagnosis, treatment and prevention of trichinellosis are reviewed.

[Secondary pulmonary hypertension in a patient with severe chronic restrictive pulmonary insufficiency--normalized during treatment with non-invasive intranasal ventilation and oxygen]. / Sekundaer pulmonal hypertension hos en patient med svaer kronisk restriktiv lungeinsufficiens--normaliseret under behandling med ikkeinvasiv maskeventilation og ilttilskud.

The present case report describes a young woman with severe restrictive lung failure, who developed pulmonary hypertension. She was treated successfully with nocturnal noninvasive nasal ventilation and oxygen, which removed symptoms and signs of cardiac incompensation. The improvement has persisted for five years.

[Toxic epidermal necrolysis]. / Toksisk epidermal nekrolyse.

A case of severe toxic epidermal necrolysis is described, stressing the importance of multiorgan system involvement of the disease. A possible pathogenetic mechanism involving tumor necrosis factor is discussed.

Influence of temperature of bupivacaine on spread of spinal analgesia.

A prospective, randomised study was performed to investigate the influence of temperature on sensory blockade in spinal anaesthesia. Three ml of plain bupivacaine 0.5% were injected intrathecally at either 4 degrees C, room temperature, or 37 degrees C. There were 10 patients in each group, who were kept sitting for 2 minutes after injection. The maximum level of sensory blockade was significantly higher (p less than 0.01) in the group who received the solution adjusted to 37 degrees C, and variability of level was smaller (p less than 0.05). Time to two-segment regression was shorter in the 37 degrees C group than in the 4 degrees C group (p less than 0.05). Hypotension required administration of ephedrine more often in the 37 degrees C group (p less than 0.05). It is concluded that the use of plain bupivacaine 0.5% adjusted to 37 degrees C results in a higher and more predictable sensory blockade.

[Assessment of early postoperative convalescence by a simple scoring system]. / Vurdering af tidlig postoperativ rekonvalescens ved hjaelp af et simpelt scoringssystem.

Fifty patients in classes 1-2 of the American Society of Anaesthesiologists (ASA) were submitted to major elective abdominal surgery. They were anaesthetised with a balanced technique and were assessed preoperatively and daily until the tenth postoperative day by a simple scoring system based on self-care. The total score fell significantly to a minimum on the first postoperative day and remained significantly decreased but with an increasing tendency until the tenth postoperative day. Patients with wound or respiratory complications had significantly lower scores than patients without complications on the sixth to ninth days. It is concluded that this simple scoring system is useful for monitoring early postoperative morbidity and it may prove of value in future investigations of surgical therapeutic regimes.

Cardiovascular function measured by ultrasound Doppler in healthy young men after ingestion of dextropropoxyphene napsylat.

In a double blind cross-over study 10 healthy male volunteers were given either 300 mg dextropropoxyphene napsylat (DP) or placebo daily for 16 days. The serum levels of DP and the metabolite nordextropropoxyphene were measured on day 3, 6 and 16. Haemodynamic measurements were made on day 1 and day 16, both at rest and during exercise. The measurements were made non-invasively, with a pulsed ultrasound Doppler. Blood pressure, heart rate, velocity, cardiac output, left cardiac work, increased during work, but showing no significant differences between the groups. The systolic time intervals were also measured by the ultrasound Doppler. The preejection period increased significantly in the DP-group, whereas the ratio preejection period/left ventricular ejection time which reflects the contractility of the heart did not differ significantly. It is concluded that DP taken daily in a normal dose for 16 days did not affect the heart function in healthy young men.

Acute carbon monoxide poisoning.

The course and outcome in terms of cerebral morbidity and hospital mortality in 79 severely carbon monoxide poisoned patients admitted to the intensive care unit during a period of 15 years is presented. Treatment consisted of administration of pure oxygen. Ninety-four per cent of the patients were artificially hyperventilated, and the majority of the patients were also treated with moderate hypothermia, steroid hormones and diuretics. Hospital mortality was 30%, and 14% of the patients were discharged after long-term hospital treatment with signs of brain damage. Due to the unpredictable cerebral course after the acute incident long-term follow-up is recommended.

Acute salicylate self-poisoning in 177 consecutive patients treated in ICU.

The course of 177 consecutive patients with severe salicylate self-poisoning treated in an intensive care unit (ICU) during a period of 15 years is presented. On admission, cerebral depression was observed in 61% respiratory failure was present in 47%, acidosis in 36% and cardiovascular function was impaired in 14%. A mortality rate of 15% was observed, which was proportionally higher in patients more than 40 years old and in patients with delayed diagnosis. Twenty-seven patients died and an autopsy was performed on 26 patients. The main autopsy diagnosis was ulcers of the gastrointestinal tract in 46%, pulmonary oedema in 46%, cerebral oedema in 31% and cerebral haemorrhage in 23%.

Respiratory depression after intrathecal opioids. Report of a patient receiving long-term epidural opioid therapy.

Morphine 20 mg and pethidine 50 mg were accidentally injected intrathecally in a patient who had received large doses of opioids epidurally for cancer pain and who had shown tolerance to their effects. The well established tolerance to spinal opioids did not protect the patient against a moderate degree of respiratory depression. Morphine concentrations 6.5 hours after the morphine injection were 103,500 ng/ml and 52 ng/ml in cerebrospinal fluid and serum, respectively.

Severe acute propoxyphene overdose: plasma concentrations of propoxyphene and norpropoxyphene and the effect of dopamine on circulatory failure.

Twelve patients with cardiovascular failure because of propoxyphene self-poisoning were treated with dopamine. The patients responded favourably to dopamine infusion (2-17 micrograms/kg/min) with a dose-dependent rise in systolic arterial blood pressure and a fall in central venous pressure and copious urinary output. Side effects during infusion were few, and in periods where dopamine infusion exceeded 10 micrograms/kg/min no tachyarrhythmias were seen. Eleven of the patients were treated on a respirator. Two patients were discharged from the ICU with signs of hypoxic brain damage, one of whom recovered completely after 2 weeks. Serum propoxyphene and norpropoxyphene were measured in nine patients. All but one patient had either propoxyphene or norpropoxyphene concentrations above 3 mumol/l.

Self-poisoning treated in an ICU: drug pattern, acute mortality and short-term survival.

A total of 1558 admissions to an ICU over 5 years because of severe self-poisoning with drugs provides the basis for this study. Three drugs accounted for 60% of the admissions: overdose with barbiturates in 28%, with tricyclic antidepressants in 19% and with propoxyphene in 14%. The annual incidence of poisonings with barbiturates and tricyclic antidepressants was the same during the period, whereas the incidence of propoxyphene intoxication increased by 80%. Intensive supportive care was the main principle of treatment. All patients were artificially ventilated. The mortality rate was 6.1%, salicylate, propoxyphene and strong analgesics having the highest mortalities (11%, 9% and 9%, respectively). A mortality rate of 3% was found following overdose with tricyclic antidepressants. By 36 months after the overdose, 235 patients (18%) had died. The expected number of deaths was 39 (3%). The suicide rate in the follow-up period was 10%, in the majority (75%) of whom death was caused by a new episode of self-poisoning.

Effect of alfentanil anaesthesia on the adrenocortical and hyperglycaemic response to abdominal surgery.

Plasma concentrations of cortisol and glucose were measured from before to 9 h after skin incision in 24 patients undergoing abdominal hysterectomy. The patients were randomly allocated to receive either high-dose alfentanil anaesthesia (150 micrograms kg-1 initially, followed by continuous infusion at a rate of 3 micrograms kg-1 min-1) or neurolept anaesthesia (droperidol 0.25 mg kg-1 plus fentanyl 5 micrograms kg-1 initially, followed by intermittent incremental doses of fentanyl 50 micrograms). The intraoperative and initial postoperative increases in plasma cortisol and glucose concentrations were inhibited (P less than 0.05) by alfentanil but, later in the postoperative period, both groups showed identical increases in cortisol and glucose concentrations. Mean arterial pressure and heart rate were more stable in the alfentanil group. The concept of "stress-free" anaesthesia during high-dose opiate administration seems to be valid during operation and for the initial 1-3 h into the postoperative period.

Severe, acute propoxyphene overdose treated with dopamine.

Six patients suffering from cardiovascular failure due to acute propoxyphene overdose, were treated with dopamine infusion in doses of 2-17 microgram/kg/min. All patients responded with increased systolic arterial blood pressure, increased urinary output and decreased central venous pressure. The two most severely poisoned patients showed no increase in heart rate in spite of dopamine infusion in positively chronotropic doses. In two out of three patients the initially abnormal ECGs normalised during treatment. It is concluded that dopamine seems suitable for reversal of propoxyphene induced circulatory failure.