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Biomedical subjects

J Ali

Publications and source records attributed to J Ali.

At least 91 records · Page 5Linked to original sources
PubMed1991

Timing and interpretation of the hemodynamic effects of the pneumatic antishock garment.

STUDY OBJECTIVES: To clarify apparently conflicting reports on the hemodynamic effects of the pneumatic antishock garment (PASG). DESIGN: Ten anesthetized dogs with hemorrhagic hypotension had hemodynamics measured without PASG inflation (group 1) and were compared with ten dogs with PASG inflation (group 2). MEASUREMENTS AND MAIN RESULTS: Baseline and immediate posthemorrhage data were similar in both groups. Group 1 maintained a carotid artery pressure of 85 +/- 9 mm Hg while group 2, by design, maintained baseline CP at 119 +/- 12 mm Hg. After PASG inflation, carotid artery flow increased by 50%, and femoral artery flow decreased tenfold. There was an immediate but transient increase (2.4 +/- 0.1 to 2.7 +/- 0.1 L/min, P less than .05) and a later decrease in cardiac output to 1.9 +/- 0.9 L/min and an increased pulmonary artery wedge pressure and central venous pressure over one hour. Saline (342 +/- 12 mL) reversed the decreased cardiac output without changing pulmonary artery wedge pressure or central venous pressure. CONCLUSION: PASG inflation, therefore, not only increases venous return and cardiac output initially by compressive venous emptying but also decreases venous return and cardiac output later by further venous compression without cardiac decompensation. Thus, apparently conflicting data are explained by the timing and interpretation of the raw hemodynamic measurements.

Animals↗
PubMed1991

The effect of the pneumatic antishock garment (PASG) on hemodynamics, hemorrhage, and survival in penetrating thoracic aortic injury.

To determine if the increased blood pressure associated with application of a pneumatic antishock garment (PASG) affects outcome in thoracic hemorrhage, we assessed hemodynamics, blood loss, and survival in three groups of eight anaesthetized piglets with a 2.5-mm laceration of the descending thoracic aorta. Baseline measurements were made before aortic hemorrhage. During one hour of aortic hemorrhage or until death of the animal, the PASG was not inflated in Group I while the PASG in the other two groups was inflated to maintain carotid artery pressure at 15 torr below baseline (Group II) and at baseline (Group III), respectively. Survival was 100% in Group I, 50% in Group II, and 0% in Group III. Hemorrhage at 22.5 +/- 4.0 mL/min stopped after 18-24 minutes in Group I; the survivors in Group II bled at a rate of 32.5 +/- 3.0 mL/min compared with 43.6 +/- 4.0 mL/min over 26-35 minutes in the Group II nonsurvivors. Group III pigs bled at 107.5 +/- 8.0 mL/min over the 10-18 minutes of survival. The intended blood pressure could not be maintained beyond 30 minutes. Bleeding stopped in Group I when the blood pressure fell to 58.2 +/- 4.5 torr from a baseline of 119.0 +/- 10.0 torr. The blood pressure fell to 48.0 +/- 5.0 torr in the four Group-II survivors. After a transient maintenance of baseline blood pressure in Group III, a precipitous drop in blood pressure with death in 10-18 minutes occurred in all these animals. In this porcine model of thoracic aortic injury, PASG inflation increases hemorrhage and mortality.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

The safety and efficacy of clarithromycin in patients with Legionella pneumonia.

Clarithromycin, a new macrolide antibiotic, is at least four times more active in vitro than erythromycin against Legionella pneumophila. In this study the safety and efficacy of orally administered clarithromycin (500 to 1,000 mg bid) in the treatment of Legionella pneumonia were evaluated. Forty-six patients were enrolled in the study, 15 of whom had not responded to previous routine anti-Legionella therapy (erythromycin, ofloxacin, rifampin [rifampicin], or tetracycline). Twelve patients prematurely discontinued the study (nine by the patient's request while feeling well; one because of cancer diagnosis; and two because of adverse events). The response rates after treatment were as follows: clinical cure rate, 98 percent (43/44); clinical success (cure or improved), 100 percent (44/44); radiographic success (cure and improved), 93 percent (28/30); direct antigen fluorescence resolution, 100 percent (40/40); and bacteriologic cure, 100 percent (13/13). Ten patients reported 13 adverse events (seven mild, four moderate, and two severe). Clarithromycin is a safe effective treatment for patients with severe chest infections due to Legionella pneumophila.

Adolescent↗
PubMed1991

Appendicular abscess presenting as neoplastic ileocecal obstruction.

Most complications after appendectomy occur within weeks of the operation. The authors present a case in which an appendicular abscess presented more than 18 years after appendectomy for acute appendicitis. The abscess simulated a neoplastic obstructive process, and a communication was demonstrated between the cecum and the abscess cavity through the appendiceal stump.

Abscess↗
PubMed1991

Pneumatic antishock garment decreases hemorrhage and mortality from splenic injury.

The effect of the pneumatic antishock garment (PASG) in controlling hemorrhage and death from splenic injury was studied in a canine model. Twelve (two groups of 6) anesthetized dogs had their spleens crushed. Carotid blood pressure, carotid blood flow, splenic artery flow and abdominal aortic flow, as well as the death rate and blood loss, were measured. Group 1 dogs did not have PASG inflation, but group 2 dogs had PASG inflation to an intraperitoneal pressure of 60 mm Hg. All group 1 dogs died within 27 to 58 minutes, but all group 2 dogs survived. Blood loss was 9.4 +/- 1.4 mL/min in group 1 and 1.6 +/- 0.9 mL/min in group 2. In group 1 carotid artery blood pressure, carotid artery flow, splenic artery flow and abdominal aortic flow fell from 120 +/- 10 mm Hg, 284 +/- 12 mL/min, 194 +/- 18 mL/min and 285 +/- 10 mL/min respectively to 0 with death of the animals. By 2 hours in group 2 dogs the carotid artery blood pressure had dropped from 116 +/- 12 to 99 +/- 12 mm Hg, and over the same period carotid artery flow, splenic artery flow and abdominal aortic flow fell from 296 +/- 8 mL/min, 190 +/- 26 mL/min and 279 +/- 16 mL/min respectively to 259 +/- 14 mL/min, 39.0 +/- 6 mL/min and 45 +/- 11 mL/min respectively. Thus, inflation of the PASG maintained carotid artery blood pressure wh ile decreasing splenic, abdominal and aortic flow as well as splenic hemorrhage, with a decrease in the death rate, over a 2-hour period.

Abdomen↗
PubMed1990

Retrieval of detached fragment of central venous pressure catheter (CVP) lodged in the right ventricle and pulmonary artery: a case report.

A successful retrieval of a detached segment of a CVP catheter by percutaneous right transfemoral venous route, using a Dotter intravascular retriever basket, is reported. The procedure was monitored under fluoroscopy. Only local anaesthesia, which was infiltrated around the puncture site, was given to the patient. No significant complication was encountered. Successful retrieval of the detached catheter fragment by percutaneous means obviates the need for thoracotomy.

Aged↗
PubMed1989

Acute and chronic Legionnaires' disease and co-existent tuberculosis: a trial of erythromycin.

To assess the prevalence of Legionnaires' disease, 115 patients with 'difficult-to-treat' chest infections were screened for Legionnella pneumophila. The results were positive in 10 (37%) of 27 patients with pulmonary tuberculosis, 15 (22%) of 68 with a recent onset acute respiratory infection, and 7 (35%) of 20 patients with history of a chronic respiratory infection. These 32 patients were enrolled in an open therapeutic trial of erythromycin. Less severe cases (17 of 32) received erythromycin stearate orally (500 mg 4-times daily) for up to 28 days, while severe cases were treated for the first few days with intravenous erythromycin lactobionate (4 g/day). Weekly chest X-ray examinations revealed prompt resolution. Most patients had no signs and symptoms detectable after 7 days, and none persisted up to 28 days. There were no therapeutic failures and microbiological tests on Day 28 were negative for Legionella pneumophila. It is suggested that the possibility of co-existing legionellosis should be considered in all patients with difficult to treat acute and chronic chest infections, particularly in developing countries where tuberculosis is very common, and treatment instituted or supplemented with erythromycin as the drug of choice.

Acute Disease↗
PubMed1989

Effect of temporary external stabilization on ventilator weaning after sternal resection.

The role of mechanical fixation of the chest wall in the treatment of flail chest remains controversial. We report a case of flail chest resulting from major sternal resection. The application of a temporary external stabilization device improved pulmonary mechanics by decreasing the respiratory rate from 36/min to 10/min while increasing tidal volume and vital capacity from 140 +/- 85 ml and 195 +/- 90 ml, respectively, to 450 +/- 110 ml and 905 +/- 310 ml, respectively. The improvement with the temporary device facilitated weaning from mechanical ventilation. We recommend consideration of this technique in selected cases of flail chest resulting from major chest wall resection.

Adult↗
PubMed1989

Legionella pneumophila: laboratory diagnosis in developing countries like Pakistan.

Three hundred random sputum samples were collected for analysis from cases of mild to severe respiratory infections and screened for Legionella pneumophila by both the culture method and also the direct fluorescent antigen test. In one third of the cases, blood specimen was also collected and screened for Legionella serum antibodies. With the direct fluorescent test it was possible to identify Legionella in 9% of the samples while the culture gave positive results in 4.3% of cases. Diagnostic antibody titers (1:256) were obtained in 12% of the samples while another 12% cases showed serum antibody titers of 1:64 to 1:128. In Pakistan where antibiotics are used extensively, the direct fluorescent examination of sputum samples gives more accurate diagnosis of Legionella cases than the culture method.

Colony Count, Microbial↗
PubMed1988

The pulmonary vascular effects of dopamine, dobutamine, and isoproterenol in unilobar pulmonary edema in dogs.

Although catecholamine inotropic drugs are often used to support the circulation of critically ill patients with hypoxemic respiratory failure, their effect on the pulmonary circulation and on gas exchange is incompletely understood. In order to improve our understanding of the effects of these drugs on the pulmonary circulation, we made measurements of total and regional intrapulmonary shunt (Qs/Qt), distribution of pulmonary blood flow, and pulmonary hemodynamics before and after infusions of dopamine (n = 6, 5 micrograms/kg/min), dobutamine (n = 6, 10 micrograms/kg/min), isoproterenol (n = 6, 0.1 micrograms/kg/min), or saline in dogs with unilobar oleic acid-induced pulmonary edema. In addition to permitting determination of the overall hemodynamic and gas exchange effects of these drugs, this preparation allowed measurement of changes in distribution of pulmonary blood flow between normal and edematous lung. In 6 dogs given dobutamine, mean cardiac output (CO) increased by 1 liter/min, while pulmonary arterial pressure (PPA) increased by 2 mm Hg with no change in pulmonary vascular resistance (PVR) or distribution of pulmonary blood flow. There was a 5% increase in mean Qs/Qt which, because of the lack of evidence of pulmonary vasoactivity, was attributed to time or to increased CO. Isoproterenol produced a similar increase in CO, but reduced PPA and PVR indicating pulmonary vasodilator activity. Pulmonary vasodilation was most prominent in edematous lung, resulting in an increase in relative blood flow to the edema lung lobe and a substantial increase in Qs/Qt, exceeding the increase in all other groups. Dopamine, similarly increasing CO, did not change overall PVR but reduced fractional blood flow to the edema lobe by 3.4% of CO. Neither Qs/Qt nor PaO2 changed significantly in this group. The differing effects of these agents on pulmonary hemodynamics, intrapulmonary blood flow distribution, and gas exchange have potentially significant implications affecting the choice of drug used for circulatory support in hypoxemic respiratory failure.

Animals↗
PubMed1988

Effect of tidal volume and PEEP on rate of edema formation in in situ perfused canine lobes.

The effects of raising tidal volume and positive end-expiratory pressure (PEEP) on rate of edema formation were studied in in situ canine left upper lobe preparations. Edema was induced by increasing blood flow to the left upper lobe (4-8 times normal). In the same animal, at equivalent flows and microvascular hydrostatic pressures, rate of edema formation observed with larger tidal volumes was significantly higher than that observed with smaller tidal volumes (0.73 +/- 0.29 vs. 0.58 +/- 0.30, P less than 0.001). Edema was also induced under static conditions (i.e., flow = 0) over a wide range of vascular pressures. Rate of edema formation was plotted against pressure and the best-fit linear regression was obtained. The slopes (g.min-1.mmHg-1.100 g-1) of the regression lines were significantly higher with larger tidal volumes compared with smaller tidal volumes [0.106 +/- 0.010 (SE) vs. 0.081 +/- 0.009, P less than 0.01]. The pressure intercepts were not different (16.1 +/- 1.6 vs. 15.7 +/- 1.8). When mean airway pressures were increased to levels equivalent to those obtained with larger tidal volumes, but by raising end-expiratory pressures, rate of edema formation dropped to levels below base line. We conclude that increasing the amplitude of cyclic changes in lung volume increases edema formation through mechanisms that are independent of changes in operating (i.e., mean) lung volume.

Animals↗
PubMed1987

Effect of bumetanide in capillary permeability pulmonary oedema.

UNLABELLED: To determine if bumetanide, like furosemide, improves shunt through pulmonary vasoactivity, 20 dogs with unilobar oleic acid pulmonary oedema were studied. Fractional perfusion and intrapulmonary shunt of the oedematous lobe were measured at: baseline, 1 1/2 hours after oleic acid infusion, 15 minutes later after either 0.1 mg X kg-1 of bumetanide in ten dogs (Bumetanide Group) or without bumetanide in ten dogs (Control Group), and 2 1/2 hours after the oleic acid, the bumetanide being administered immediately after the 1 1/2 hours post-oleic acid measurements. Lobar shunts for the Bumetanide Group were: 9.3 +/- 4.0, 54.3 +/- 13.6, 54.7 +/- 13.6, 38.6 +/- 12.0 per cent and for CONTROLS: 8.7 +/- 1.6, 45.1 +/- 8.8, 48.3 +/- 7.8, 70.4 +/- 6.2 per cent. Fractional perfusions of the oedematous lobe were: 29.9 +/- 1, 14.7 +/- 1.1, 14.6 +/- 0.7, 19.3 +/- 1.9 per cent in the Bumetanide Group and 28.6 +/- 2.1, 14.2 +/- 1.1, 14.2 +/- 1.5, and 9.9 +/- 1.1 per cent in CONTROLS. Oedema (wet to body weight ratio) was less (p less than 0.05) in the contralateral lobe (2.5 +/- 0.2 vs. 2.9 +/- 0.3) and the oedematous lobe (4.7 +/- 0.4 vs 6.0 +/- 0.5) after bumetanide-induced diuresis. We conclude that bumetanide decreases shunt by decreasing oedema and not through pulmonary vasoactivity.

Animals↗
PubMed1987

Longitudinal distribution of pulmonary vascular resistance with very high pulmonary blood flow.

Dog left upper lobes (LUL) were perfused in situ via the left lower lobe artery. Lobe weight was continuously monitored. Increasing lobar flow from normal to 10 times normal had little effect on left atrial pressure, which ranged from 1 to 5 mmHg. There was a flow threshold (Qth) below which lobar weight was stable. Qth ranged from 1.1 to 1.55 l/min (mean 1.27) corresponding to four times normal LUL blood flow. Above Qth, step increases in lobar flow resulted in progressive weight gain at a constant rate that was proportional to flow. The effective pressure at the filtration site (EFP) at different flow rates was estimated from the static vascular pressure that resulted in the same rate of weight gain. From this value and from mean pulmonary arterial (PA) and left atrial (LA) pressures, we calculated resistance upstream (Rus) and downstream (Rds) from filtration site. At Qth, Rds accounted for 60% of total resistance. This fraction increased progressively with flow, reaching 83% at Q of 10 times normal. We conclude that during high pulmonary blood flow EFP is closer to PA pressure than it is to LA pressure, and that this becomes progressively more so as a function of flow. As a result, the lung accumulates water at flow rates in excess of four times normal despite a normal left atrial pressure.

Animals↗
PubMed1987

Arterial occlusion versus isofiltration pulmonary capillary pressures during very high flow.

Pressure in the compliant middle segment of the pulmonary vascular bed (PM), as determined by arterial occlusion, was compared with pressure at the filtration site (effective filtration pressure, EFP), determined by the isofiltration technique, at very high (7-10 times normal) pulmonary flow in six in situ perfused canine left upper lobes. At these flow rates inflow and left atrial pressures averaged 41.9 +/- 1.3 and 2.5 +/- 0.5 (SE) mmHg, respectively. PM was 30.9 +/- 1.6 mmHg, and EFP was 32.3 +/- 1.9 mmHg with no significant difference between the two measurements by paired t test. The results indicate that the arterial occlusion technique yields a pressure that is equivalent to EFP even during very high pulmonary blood flow where the longitudinal distribution of resistance is quite different from that obtained during normal flow.

Animals↗
PubMed1987

Does indomethacin affect shunt and its response to PEEP in oleic acid pulmonary edema?

We assessed hemodynamics, lobar perfusion, and shunts at base line 1.5 h after unilobar oleic acid edema, 15 min after indomethacin (10 mg/kg iv), and 15 min after positive end-expiratory pressure (PEEP) (10 cm) in 10 dogs. In 10 additional dogs (control) the same measurements were made but no indomethacin was administered. Shunts of the edematous lobe were: 10.6 +/- 6.3, 54.1 +/- 22.8, 30.8 +/- 16.6, and 12.4 +/- 6.3% for dogs administered indomethacin and 10.9 +/- 4.2, 53.8 +/- 13.1, 72.3 +/- 14.6, and 11.5 +/- 4.1% for the controls. Perfusions (% cardiac output) to the edematous lobe were 27.6 +/- 3.6, 14.6 +/- 2.0, 9.9 +/- 1.5, and 27.9 +/- 2.9% in the dogs administered indomethacin and 27.3 +/- 3.1, 14.0 +/- 1.7, 13.2 +/- 1.3, and 26.9 +/- 2.8% in controls. The decrease in lobar perfusion was similar before indomethacin with a further decrease in lobar perfusion and an increase in lobar vascular resistance 15 min after indomethacin. The increase in vascular resistance of the edematous lobe was three times that of nonedematous lobes after indomethacin (149.6 +/- 76% vs. 58.0 +/- 43%). Indomethacin, therefore, decreases shunt possibly by enhancing alveolar hypoxic vasoconstriction and does not block the improvement in shunt with PEEP.

Animals↗
PubMed1987

Decreasing hydrostatic pressure does not uniformly decrease high-pressure pulmonary edema.

Pulmonary artery wedge pressure (PAWP) of 30 mm Hg with left atrial balloon inflation for 1 1/2 hours produced pulmonary edema in eight dogs. PAWP was then decreased to 10 mm Hg for two hours, and shunt, lung water (extravascular thermal volume, or ETV, by thermal dye), and perfusion distribution (radiomicrosphere technique) were measured and compared with four other dogs (group 1) whose PAWP was maintained at 10 mm Hg. The eight dogs with PAWP of 30 mm Hg for 1 1/2 hours were retrospectively subdivided into two groups of four based on ETV (group 2, double baseline ETV; group 3, triple baseline ETV). Baseline ETV and shunt were similar for all groups and remained unchanged for group 1. At 1 1/2 hours, 2 hours (1/2 hour after decreasing PAWP), 2 1/2 hours, and 3 1/2 hours, respectively, ETV were: 13.9 +/- 1.9, 12.8 +/- 2.0, 9.3 +/- 1.5, and 8.5 +/- 1.0 ml/kg in group 2; and 21.9 +/- 2.1, 22.7 +/- 2.2, 22.5 +/- 2.0, and 22.2 +/- 2.0 ml/kg in group 3. A more variable rate of edema formation was detected in eight additional dogs, but failure to resolve higher levels of edema after decreasing PAWP was also demonstrated in this group. Edema was greatest in lower lobes and decreased lobar perfusion. Shunt was higher in group 3 than in group 2 at 1 1/2 hours and decreased in group 2 but not in group 3 at 3 1/2 hours. Changes in colloid osmotic pressure may account for the differences in edema formation and resolution, but our data suggest that, independent of the rate of edema formation, a decrease in vascular exchange surface area at higher levels of edema may inhibit edema resolution when PAWP is decreased.

Animals↗
PubMed1987

Colloid osmotic pressure in pulmonary edema clearance with furosemide.

After tripling of baseline lung water (EVLW), decreasing wedge pressure (PWP) alone for two hours did not decrease EVLW. In 11 of 16 dogs, triple baseline EVLW and a decrease in plasma colloid osmotic pressure (COP) from 21.1 +/- 0.8 to 17.8 +/- 0.8 mm Hg resulted from left atrial balloon inflation at PWP of 28 to 30 mm Hg. With subsequent lowering of PWP to 10 mm Hg, intravenously administered furosemide (1 mg/kg) was given to these 11 dogs. One half hour after furosemide, shunt decreased slightly without decreasing EVLW in all 11 dogs, but by two hours, seven dogs (group 1) decreased EVLW (from 23.2 +/- 1.8 to 11.1 +/- 1.4 ml/kg) and shunt (37.4 +/- 2.0 to 12.9 +/- 2.9 percent), while four dogs (group 2) did not (EVLW: 22.3 +/- 1.4 to 22.5 +/- 0.6 ml/kg: shunt, 36.8 +/- 1.7 to 36.5 +/- 1.9 percent). Group 1 had diuresis, maintained normal blood urea nitrogen and creatinine levels, and increased COP from 17.7 +/- 0.7 to 23.6 +/- 0.5 mm Hg while group 2 was oliguric with elevated BUN and creatinine values and showed no change in COP (17.9 +/- 0.9 to 18.3 +/- 0.6 mm Hg) after furosemide. After decreasing PWP in massive pulmonary edema (triple baseline EVLW), furosemide appeared to enhance edema clearance by changes in COP with diuresis.

Animals↗