摘要:

In cooperation with a group of general practitioners (GP), we investigated the possible risk and benefit of prehospital initiation of thrombolytic therapy in acute myocardial infarction (AMI) with anisoylated plasminogen streptokinase activator complex (APSAC) at the patient's home. During a 14-month period, 58 patients with suspected AMI were evaluated by their GP using a protocol with strict inclusion and exclusion criteria. The GP alerted a special mobile intervention team which administered APSAC at home in 13 of the 19 patients; Coronary reperfusion was achieved in ten of these 13 patients. Apart from short and easily treated episodes of bradycardia and/or hypotension after the injection of the thrombolytic drug in four of 13 patients, no major adverse events were noted in the early treatment period. The estimated time gain by treating the patient at home instead of starting the treatment in the coronary care unit was 46 ± 14 min. Therefore, athome initiation of thrombolytic treatment seems feasible, fast, and safe.

ISSN:0090-3493    

出版商:OVID    

年代:1988

数据来源: OVID

摘要:

We examined the effect of spontaneous breathing with continuous positive airway pressure (CPAP) on the plasma concentrations of immunoreactive (ir) alphaatrial natriuretic peptide (ANP). In three experiments, each of 11 healthy male volunteers performed CPAP at 20, 10 and 0 cm H2O for 2 h during continuous volume loading. Samples were drawn from a peripheral vein. Plasma concentrations of irANP were determined by a sensitive radioimmunoassay. Significantly lower concentrations of irANP were observed during 20 cm H2O CPAP than at 10 and 0 cm H2O. The concentrations of irANP did not differ significantly when individuals breathing with CPAP at 10 and at 0 cm H2O were compared. Our data suggest that CPAP at 20 cm H2O lowers the release of ANP in volume-expanded subjects. We hypothesize that this phenomenon may contribute to the fluid retention and renal dysfunction observed frequently during high CPAP levels. The decline in plasma concentrations of irANP may be the result of atrial compression by the distended lungs and of reduced venous return to the heart during CPAP.

ISSN:0090-3493    

出版商:OVID    

年代:1988

数据来源: OVID

摘要:

Ninety-six arterial catheters from 75 different anatomical sites in 56 surgical ICU patients were studied prospectively to determine the rate of catheter-related infection associated with prolonged arterial catheterization (defined as > 96 h). Every 96 h, all catheters were semiquantitatively (SQ) cultured and the percutaneous entry site was swab cultured. Sites were used indefinitely by exchanging the catheters over a guidewire every 96 h as long as arterial monitoring was necessary and SQ cultures remained negative ≥15 colonies). No sites used < 96 h developed skin colonization, while 14/51 (27%) sites used > 96 h developed positive swab cultures. No SQ cultures were positive in sites with negative swab cultures (p< .001). Catheter-related infection (a positive SQ culture) developed in 4/42 (9.5%) radial or femoral sites compared to 4/9 (44%) axillary sites used > 96 h (p< .01).It is concluded that arterial catheter-related infection develops in <10% of radial or femoral sites used > 96 h, and 90% of radial and femoral sites may be used safely for prolonged periods if skin colonization at the percutaneous sites is controlled and SQ catheter cultures remain negative. Skin site swab cultures may be useful for determining when arterial catheters should be removed and SQ cultured.

ISSN:0090-3493    

出版商:OVID    

年代:1988

数据来源: OVID

摘要:

Aminoglycoside (gentamicin, tobramycin) dosage regimens and subsequent serum concentrations were compared in 30 patients treated initially using traditional physician-determined methods and then switched to a pharmacokinetic-based treatment program. Patients received more drug during the kinetic phase (median 5 μg/kg) than during the traditional phase (median 3.6 mg/kg) and achieved greater peak serum concentration (5.9 vs. 4.4 μg/ml). Seventy-three percent of kinetic peak values but only 27% of traditional peak values exceeded 5.0 μg/ml. Trough concentrations were comparable in both phases of study and no nephrotoxicity was observed. This pharmacokinetic-based management program achieved more consistently greater therapeutic peak concentrations and provided more individualized therapy than did physicians. The use of pharmacokinetic consultants may be of benefit in administering safely optimal aminoglycoside therapy.

ISSN:0090-3493    

出版商:OVID    

年代:1988

数据来源: OVID

摘要:

Transcutaneous O2(Ptco2) tensions were compared with Pao2measurements in 57 infants and children (age range 2 wk to 15.5 yr) using electrode temperatures of 43° and 44°C. At both temperatures, the relationships between Ptco2and Pao2were linear over the whole range of data (Pao239.75 to 120 torr) although mean Ptco2/Pao2fell from 44° to 43°C. Skin stripping by repeated applications of adhesive tape immediately before electrode placement did not improve these relationships. In an additional 20 children with, a mean age of 2.4 yr (range 0.08 to 15.85) who were being investigated for sleep-disordered breathing, the mean Pao2/Ptco2ratio of 1.22 at 44°C was used as a correction factor during air calibration for Ptco2. This resulted in a mean Ptco2/Pao2of 0.99 (range 0.83 to 1.15) provided blood flow is not impaired. Extending the monitoring period from 4 to 8 h between site changes did not result in any burns or persisting erythema. In hemodynamically stable infants and children, and at electrode temperatures of 44° and 43°C, Ptco2is linearly related to Pao2over a wide range of Pao2values. At an electrode temperature of 44°C, Ptco2can be arterialized effectively by allowing for transepidermal O2loss during air calibration; at this electrode temperature, intervals between site changes can be extended safely up to 8 h.

ISSN:0090-3493    

出版商:OVID    

年代:1988

数据来源: OVID

摘要:

Oxygen-derived free radicals have been implicated as mediators of cellular injury in several model systems. Recently, a role for free radicals has been proposed in the mortality associated with Gram-negative bacterial sepsis. To determine if pretreatment with free radical scavengers can prevent endotoxin-induced mortality, mice rendered sensitive to endotoxin with actinomycin D were treated with either superoxide dismutase (SOD), N-acetylcysteine (NAC) or saline and were then challenged with a dose of endotoxin calculated to cause a mortality of >80%. Mortality was assessed at 12-h intervals after challenge. Increased survival was seen in the SOD-treated group compared to the control group (p± .05). In contrast, survival in mice treated with NAC, another potential scavenger, was not significantly different from the control group. These results support the hypothesis that superoxide and hydroxyl radicals contribute to mortality in Gram-negative bacterial sepsis.

ISSN:0090-3493    

出版商:OVID    

年代:1988

数据来源: OVID

摘要:

To determine the influence of arachidonic acid metabolites on acute lung injury induced by glass bead embolism, two groups of animals were studied before and after the pulmonary artery pressure was doubled by glass bead embolism. One group represented an untreated time control (n = 6) while the second group (n = 6) was pretreated with 25 mg/kg of iv ibuprofen. Repeat measurements were taken at 30, 60 and 90 min after glass bead embolism. Compared to the untreated group, the pretreated group had only a slightly decreased Pao2(pretreated, 82% of baseline vs. untreated, 35% of baseline,p< .05). The initial elevation in pulmonary vascular resistance (PVR) was similar in both groups but in the pretreated group it had returned nearly to baseline values by the end of the study in contrast to the persistent elevation of the PVR observed in the untreated group.We conclude that pretreatment with ibuprofen resulted in improved arterial oxygenation and a reduction in PVR over the time period studied. This implicates a role for arachidonic acid metabolites in the pathophysiology of this injury.

ISSN:0090-3493    

出版商:OVID    

年代:1988

数据来源: OVID

摘要:

Because it is difficult to verify the efficacy of hemorrhagic shock treatment, we compared subcutaneous O2tension (Psco2) with liver oxygenation in efforts to correct shock in piglets with two different colloids, hydroxyethyl starch (HES-120) and dextran-70. Nineteen animals were bled to shock and the shed blood was retransfused in the control group. Liver oxygenation was measured directly by means of a silicone tube used as a tonometer, and indirectly by calculating liver O2consumption (Vo2). Psco2was monitored with a needle electrode. The two colloid groups were compared by measuring plasma lactate, and the plasma colloid osmotic pressure (COPp).Psco2followed closely the changes in liver tissue Po2during the experiment; it seems to be a useful tool in estimating volume filling during the treatment of hemorrhagic shock. A wider variation was noted in calculated liver Vo2compared with hepatic venous Po2or liver tissue Po2. Despite the fact that COPpincreased to a higher level after the administration of dextran, HES proved to be at least as effective as dextran in restoring mean arterial pressure, cardiac output, liver oxygenation, Psco2, arterial pH, arterial plasma lactate, and liver lactate uptake.

ISSN:0090-3493    

出版商:OVID    

年代:1988

数据来源: OVID

摘要:

The cerebral effects of iv fluids have not been well defined, particularly the differences between crystalloids and colloids. We thus evaluated the effects of lactated Ringer's (LR) and 6% hetastarch (HES) solutions on brain edema, intracranial pressure (ICP), and cerebral blood flow (CBF) in anesthetized rabbits, using a model of isovolemic hemodilution (IVHD). In this model, arterial blood was removed at a rate of ± 2 ml/ min for one hour and replaced simultaneously with LR or HES in amounts needed to maintain arterial BP and CVP; Hct decreased from ± 40% to ± 19%. Thirty-six animals were divided into three groups (n = 12 each): a) IVHD with LR, b) IVHD with HES, and c) maintenance LR without hemodilution. To permit the examination of both acute and delayed fluid effects, each group was further divided into two subgroups (n = 6 each): one in which animals were sacrificed immediately on completion of the one-hour IVHD period (early), and one in which animals were sacrificed 4 h later (late). After sacrifice, brain and skeletal muscle water contents (% H2O) were determined, and the specific gravity (SpGr) of multiple brain samples was measured. Much larger volumes of LR were required to maintain normovolemia as compared with HES, (e.g., totals 203 ± 68 vs. 76 ± 18 ml/kg, respectively in late animals) and those given LR had larger increases in body weight and muscle % H2O. There was a significant increase in ICP (3 to 4 mm Hg) with LR that was maximal on completion of IVHD at one hour, but which normalized over the next 4 h. In LR animals sacrificed early, brain % H2O was increased, and tissue SpGr had decreased. However, in the late subgroup, these changes were not present. No changes in ICP, brain % H2O or SpGr were noted in HES animals at either sacrifice time. These results indicate that large amounts of LR can produce measurable but transient increases in both ICP and brain water. However, the contribution of changing colloid oncotic pressure (COP) vs. osmolality are not clear, since COP measurements were not available, and osmolality decreased slightly in LR animals. Nevertheless, it may be advisable to limit the volumes of LR in patients at risk for cerebral edema or intracranial hypertension.

ISSN:0090-3493    

出版商:OVID    

年代:1988

数据来源: OVID

摘要:

This study compares the thermal transfer and rewarming characteristics of heated aerosol inhalation (HAI) alone and combined with peritoneal lavage (PEL) or pleural lavage (PLL). Closed-system PEL and PLL are equally efficient at rewarming hypothermic dogs and do so at a rate approximating 6°C/h/m2. Cardiovascular responses to PEL and PLL were similar. Serum electrolytes, protein, Hct, and arterial blood gases were comparable and little changed when compared in prehypothermia and postrewarming periods. HAI alone provides little heat for rewarming; more heat is realized from endogenous metabolism. Nevertheless, HAI's ease of use and possible selective cardiac rewarming characteristics argue for its inclusion with other methods of active rewarming. The use of PEL or PLL is governed by clinical circumstances.

ISSN:0090-3493    

出版商:OVID    

年代:1988

数据来源: OVID