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Patel KR, Paidas CN. Phlegmasia cerulea dolens: the role of non-operative therapy. CARDIOVASCULAR SURGERY (LONDON, ENGLAND) 1993; 1:518-23. [PMID: 8076089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Thrombectomy and thrombolysis are often advocated in the treatment of phlegmasia cerulea dolens, but frequently result in incomplete clot removal, recurrence of thrombosis, local and systemic hemorrhagic complications and chronic venous stasis; this state is associated with a rate of major amputation and death of up to 50%. Non-operative therapy includes elevation, hydration and heparinization and excludes all methods aimed at surgical removal or chemical lysis of the thrombus. In 1982 it was decided to use non-operative therapy as the first line of treatment for phlegmasia cerulea dolens. In the last 9 years seven extremities in six patients with this condition have been treated. One patient had advanced gangrene on presentation and one underwent emergency thrombectomy. Five extremities (in five patients) were treated with non-operative therapy. Ischemia was rapidly corrected in all five patients. Edema resolved completely after 3-4 days in four patients. There were no complications attributable to the therapy. Two of six (33%) patients died from terminal disease. Non-operative therapy appears to be effective in preventing limb loss and avoiding the risks of thrombectomy and thrombolysis in critically ill patients.
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Ghosh SK, Rafferty P, De Vos C, Patel KR. Effect of cetirizine, a potent H1 antagonist, on platelet activating factor induced bronchoconstriction in asthma. Clin Exp Allergy 1993; 23:524-7. [PMID: 8103703 DOI: 10.1111/j.1365-2222.1993.tb03241.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Effect of cetirizine, a potent and specific H1 receptor antagonist, was examined on platelet activating factor-induced bronchoconstriction in 10 patients (5 male, mean [s.e.m.] aged 37.4 [3.6] years) with mild asthma in a placebo controlled, double-blind cross-over study. Airway responses were assessed by measuring specific airway conductance (SGaw). Patients were challenged with a single dose (12-96 micrograms) of PAF that had previously produced a 35% fall in SGaw. PAF challenges were performed after single dose (15 mg) and 1 week's treatment (15 mg twice daily) of cetirizine. There was no significant difference in pre- and post-treatment baseline values of SGaw on different study days and the percentage changes after cetirizine were 38.7 (7.01) and 45.6 (5.52) compared to 50.2 (2.89) and 43.9 (7.26) with placebo respectively. Similarly mean (s.e.m.) area under curve (AUC-SGaw/time course response) was 391 (143) and 514 (85) with cetirizine compared to 565 (37) and 461 (94) with placebo respectively. The difference was not statistically significant. There was no difference in facial flushing and feeling of warmth between cetirizine and placebo. We conclude that PAF induced bronchoconstriction in humans is not mediated by histamine release and that H1 receptor antagonists do not modify PAF induced bronchoconstriction.
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Rafferty P, Ghosh SK, de Vos C, Patel KR. Effect of oral and inhaled cetirizine in allergen induced bronchoconstriction. Clin Exp Allergy 1993; 23:528-31. [PMID: 8369980 DOI: 10.1111/j.1365-2222.1993.tb03242.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Cetirizine is a potent, selective H1 histamine receptor antagonist. The effect of oral and inhaled cetirizine was assessed on the early bronchoconstrictor response to inhaled allergen in 10 mild atopic asthmatic patients in a double-blind, randomized, placebo controlled trial. All were sensitive to Dermatophagoides pteronyssinus and this was used as the provoking allergen. The geometric mean PD20 FEV1 values obtained at allergen challenge were measured as cumulative breath units (c.b.u.) and following oral cetirizine, inhaled cetirizine and placebo were 124.5, 75.7 and 76.7 c.b.u. respectively. These did not differ significantly. We conclude that neither oral nor inhaled cetirizine significantly attenuates the early response to inhaled allergen in atopic asthmatic subjects. However, the method of repeated allergen challenge is likely to be relatively insensitive.
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Albazzaz MK, Neale MG, Patel KR. Dose duration of nebulized nedocromil sodium in exercise-induced asthma. Eur Respir J 1992. [DOI: 10.1183/09031936.93.05080967] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The dose-duration effect of nebulized nedocromil sodium was studied in ten patients with exercise-induced asthma (7 males mean (SEM) age 30.1 (3.5) yrs and predicted forced expiratory volume in one second (FEV1) 102%). All of these patients showed > 40% protection of their exercise asthma with 4 mg of nedocromil sodium delivered via metered dose inhaler. Three concentrations of nedocromil sodium (0.5, 2.5 and 10 mg.ml-1) and placebo were administered in double-blind, randomized manner. One ml of each solution was nebulized via a Wright nebulizer. Effects were assessed from the mean maximal percentage fall in FEV1 after 6-8 min treadmill exercise at 15, 135 and 255 min following each treatment and expressed as percentage protection. The mean baseline FEV1 values before and after treatments were comparable on four days of testing. Nedocromil sodium inhibited exercise-induced fall in FEV1 at all concentrations (p < 0.001) and the inhibitory effect was still present at 255 min. No differences were observed between active treatments.
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Patel KR, Clauss RH. A technique to prevent detachment of the Fogarty catheter from the Leather valve cutter during in situ bypass. J Vasc Surg 1992; 16:496-7. [PMID: 1522656 DOI: 10.1016/0741-5214(92)90393-m] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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Albazzaz MK, Neale MG, Patel KR. Dose duration of nebulized nedocromil sodium in exercise-induced asthma. Eur Respir J 1992; 5:967-9. [PMID: 1330676] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The dose-duration effect of nebulized nedocromil sodium was studied in ten patients with exercise-induced asthma (7 males mean (SEM) age 30.1 (3.5) yrs and predicted forced expiratory volume in one second (FEV1) 102%). All of these patients showed > 40% protection of their exercise asthma with 4 mg of nedocromil sodium delivered via metered dose inhaler. Three concentrations of nedocromil sodium (0.5, 2.5 and 10 mg.ml-1) and placebo were administered in double-blind, randomized manner. One ml of each solution was nebulized via a Wright nebulizer. Effects were assessed from the mean maximal percentage fall in FEV1 after 6-8 min treadmill exercise at 15, 135 and 255 min following each treatment and expressed as percentage protection. The mean baseline FEV1 values before and after treatments were comparable on four days of testing. Nedocromil sodium inhibited exercise-induced fall in FEV1 at all concentrations (p < 0.001) and the inhibitory effect was still present at 255 min. No differences were observed between active treatments.
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Patel KR, Boon AP. Metastatic breast cancer presenting as an ovarian cyst: diagnosis by fine needle aspiration cytology. Cytopathology 1992; 3:191-5. [PMID: 1511124 DOI: 10.1111/j.1365-2303.1992.tb00045.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
A fifty-year-old woman with a history of breast cancer presented with a clinically benign ovarian cyst. Laparoscopic aspiration of cyst fluid was performed and the cytology was suspicious of epithelial neoplasia. At subsequent hysterectomy and bilateral salpingo-oophorectomy, the specimen showed extensive metastatic breast carcinoma. Although the cytological examination of fluid from ovarian cysts is often unrewarding, this case shows that metastatic carcinoma may occasionally be diagnosed in this fashion.
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Patel KR, Chan FA, Batista RJ, Clauss RH. True venous aneurysms and arterial "steal" secondary to arteriovenous fistulae for dialysis. THE JOURNAL OF CARDIOVASCULAR SURGERY 1992; 33:185-8. [PMID: 1572875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
In patients requiring hemodialysis, arteriovenous fistulae may be created using autogenous vessels or prosthetic grafts. Complications of such operations include thrombosis, infection, venous hypertension, pseudoaneurysm, congestive heart failure, true venous aneurysms, and arterial "steal" syndrome. Of these the last two are the least common. On reviewing the English literature (Medline search: 1969-1991) we found only 8 reported cases of true venous aneurysms secondary to creation of an arteriovenous fistulae for dialysis. Hemodynamic assessment has shown that arterial "steal" is frequently present distal to an arteriovenous fistula. However, these patients rarely have ischemic symptoms. Over the last 7 years 236 patients had arteriovenous fistulae created for hemodialysis at our institution. Three of these patients (1.2%) developed true venous aneurysms. One of these 3 patients (0.4%) also had severe hand claudication due to arterial "steal". All of these patients were treated successfully without any complications. The etiology and various therapeutic options for these rare complications are discussed.
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Patel KR, Ghosh SK, Matcham J. Lack of dose-response effect of terfenadine on resting bronchomotor tone in patients with asthma. Clin Exp Allergy 1991; 21:363-6. [PMID: 1677829 DOI: 10.1111/j.1365-2222.1991.tb01669.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Bronchodilatation data from three, four-period cross-over studies were combined to assess the effect of oral terfenadine 60, 120, 180 mg and placebo on the airways of 26 patients with atopic asthma. Meta-analysis of these data showed that mean changes in FEV1 from pre-dose to 4 hr were 11.4, 14.6 and 11.8% for the three doses of terfenadine, respectively, and -2.9% for placebo. There was a significant treatment effect (P = 0.0001) but no effect of dose. Terfenadine, a non-sedating histamine H1-receptor antagonist, caused bronchodilatation in a single dose. Whether this effect is sustained with long-term treatment requires further investigation.
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Ghosh SK, De Vos C, McIlroy I, Patel KR. Effect of cetirizine on histamine- and leukotriene D4-induced bronchoconstriction in patients with atopic asthma. J Allergy Clin Immunol 1991; 87:1010-3. [PMID: 1673975 DOI: 10.1016/0091-6749(91)90424-m] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Cetirizine, a derivative of hydroxyzine, is a new compound with potent antihistaminic property without antiserotonin and anticholinergic activities. The effect of both a single dose (15 mg) and 7 days of treatment (15 mg twice daily) with cetirizine, a potent H1 antagonist on bronchoconstriction induced by histamine and leukotriene D4 (LTD4) has been examined in 10 patients with mild atopic asthma in a placebo-controlled, double-blind, crossover study. Cetirizine, after a single dose and 7 days of treatment with placebo, the geometric mean values of the provocative concentration of histamine causing a 20% fall in FEV1 (millimolars) were 1.60 (95% confidence interval, 0.82 to 3.11) and 1.67 (0.77 to 3.65), compared with 118.07 (77.22 to 180.54) (p less than 0.0001) and 53.16 (20.50 to 137.84) after cetirizine administration (p less than 0.0002). The mean inhibition after a single dose was twofold higher than after 1 week of treatment (p less than 0.05). After a single dose and 7 days of treatment with placebo, the geometric mean values of the provocative concentration of LTD4 causing a 20% fall in FEV1 (micromolars) were 2.26 (1.74 to 2.94) and 2.37 (1.77 to 3.17), compared with 3.90 (2.60 to 5.86) (p less than 0.05) and 3.21 (2.28 to 4.52) after cetirizine administration. This result suggests that cetirizine is a potent H1 antagonist in the human airways. Diminished activity after 1 week of treatment suggests subsensitivity of H1 receptors developing in human airways. The small protective effect after a single dose against LTD4-induced bronchoconstriction indicates a nonspecific rather than a specific receptor antagonism.
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Abstract
The effect of oral and inhaled cetirizine, a potent and specific H1 receptor antagonist, was studied in patients with exercise induced asthma. Twelve patients (five male; mean age 35.2 years) were given oral placebo or cetirizine 10 mg twice daily for one week, double blind and in randomised order, and exercised on a treadmill for six to eight minutes at a submaximal work load two hours after the final dose. There was no significant change in baseline FEV1 after treatment and cetirizine failed to inhibit exercise induced bronchoconstriction (maximum falls in FEV1 28% and 27% of baseline). In a further eight patients (four male; mean age 40.8 years) the effect of 1 ml cetirizine (5 and 10 mg/ml) given through a Wright nebuliser was compared with that of placebo in a double blind trial. The fall in FEV1 after exercise was reduced after both concentrations of cetirizine by 15.2% of baseline after 5 mg/ml and by 10.2% after 10 mg/ml, compared with 23.7% after placebo. In two patients cetirizine had no effect. In a further study cetirizine (10 mg/ml) given by inhalation displaced the geometric mean PC20 histamine 13.1 fold to the right by comparison with placebo. The reason for the difference between the effects of oral and of inhaled cetirizine on exercise asthma is not clear but may be related to differences in local concentration in the airway.
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Patel KR, Chan FA, Kerr A, Clauss RH. Subclavian artery to innominate vein fistula after insertion of a hemodialysis catheter. J Vasc Surg 1991; 13:382-4. [PMID: 1999857 DOI: 10.1067/mva.1991.24825] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Insertion of hemodialysis catheters for temporary use is now preferentially performed by percutaneous infraclavicular subclavian vein catheterization. This method involves passage of a stiff dilator and a peel-away sheath over a guide wire, and is usually carried out without fluoroscopy. For the most part this has proved to be a valuable and safe approach. However, a small incidence of major complications occurs, which needs to be emphasized. Sixteen cases of arteriovenous fistulas between the subclavian artery or its branches and the subclavian vein have been reported so far in the literature. To date only one case of subclavian artery to innominate vein fistula has been reported. We report the second case with this complication and suggest possible preventive measures.
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Patel KR. Prolonged treatment with oral and inhaled tulobuterol does not induce airways tachyphlaxis. Lung 1990; 168 Suppl:210-8. [PMID: 1974679 DOI: 10.1007/bf02718135] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Beta 2-agonists have been shown to induce beta 2-adrenoceptor downregulation in vivo and in vitro. Whether this has any functional relevance remains unclear. Tulobuterol is a new synthetic beta 2-agonist with potent and prolonged bronchodilator activity when given by oral and inhaled routes. The effect of tulobuterol aerosol (400 micrograms q.i.d.) and tulobuterol tablets (2 mg b.i.d.) was studied in patients with chronic asthma and reversible airways obstruction in two separate trials. Tulobuterol produced significant bronchodilatation after the first and final dose over a 6-h period and the effects were comparable. The bronchodilator activity of tulobuterol given by inhalation and oral routes was not attenuated after 6 months of continuous treatment. There was significant improvement in symptom score and lung function measurements. Side effects, predominantly tremors, were observed at the start of treatment with tablet formulation but the incidence and severity of tremors decreased after 6 months. The changes in BP and pulse rate were not clinically significant. These results confirm the potent bronchodilator activity of tulobuterol and the lack of tachyphylaxis after prolonged treatment.
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Farley RD, Dougall JR, Patel KR. Development of a probe for the in vivo measurement of airway humidity during anaesthesia. JOURNAL OF BIOMEDICAL ENGINEERING 1990; 12:328-32. [PMID: 2395359 DOI: 10.1016/0141-5425(90)90008-b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Airway drying can arise during long-term respiration of anaesthetic dry gases and this may have implications for the function of the airway wall. Monitoring airway humidity can identify drying trends, although previous attempts have been limited for technical reasons. The design and development of a probe to measure mid-tracheal air humidity is described. The device comprises a commercially available capacitive humidity sensor and a thermocouple. The assembled probe is catheter-like with a diameter of 9.5 mm and a length of 312 mm. Water vapour transfer response times of 1.4s (absorption) and 3.6s (desorption) were evaluated for the probe. A preliminary trial to record airway humidity in ambient air and involving six patients was performed during anaesthesia.
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Schraufnagel DE, Patel KR. Sphincters in pulmonary veins. An anatomic study in rats. THE AMERICAN REVIEW OF RESPIRATORY DISEASE 1990; 141:721-6. [PMID: 2310100 DOI: 10.1164/ajrccm/141.3.721] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
To better understand blood flow and edema formation in the lung, anatomic evidence for venous sphincters was sought by a scanning electron microscopic investigation of vascular casts in the rat. In the first study, indentations in the casts of veins and arteries were compared. Casts of the pulmonary veins had narrow (1 to 3 microns) circumferential constrictions about every 30 microns in length (range 20 to 50 microns) and before and after accepting tributaries. Most arteries had no constriction. Infrequently, arterial narrowing occurred over long distances (greater than 30 microns). To determine if these indentations could be altered by a neural stimulus, a second study tried to cast the pulmonary microcirculation after the rats were given a blow to the head, but was unsuccessful. In a third study, the pulmonary vasculature of anesthetized rats was cleared and cast. As the resin began to harden and the animals' circulation ceased, half the animals were given a sharp blow on the head. The casts of the veins in the animals that received the blow had deeper bands than the control animals (p less than 0.001). Pulmonary veins have annular constrictions (sphincters) that are strategically located to influence blood flow. They deepen in response to the neural discharge of a head blow and should be considered in the study of neurogenic pulmonary edema.
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Albazzaz MK, Neale MG, Patel KR. Dose-response study of nebulised nedocromil sodium in exercise induced asthma. Thorax 1989; 44:816-9. [PMID: 2556807 PMCID: PMC1020849 DOI: 10.1136/thx.44.10.816] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Ten patients with exercise induced asthma, in whom inhaled nedocromil sodium 4 mg by metered dose inhaler attenuated the exercise fall in forced expiratory volume in one second (FEV1) by at least 40%, participated in a double blind dose response study to compare the protective effect of nedocromil sodium given 15 minutes before exercise challenge via a nebuliser (Wright) in concentrations of 0.5, 5, 10, and 20 mg/ml with that of placebo (saline). Response was assessed as the maximum fall in FEV1 after the patient had run on a treadmill for six to eight minutes. Plasma concentrations of nedocromil sodium were measured at the time of challenge. After exercise challenge the mean (SEM) maximum percentage falls in FEV1 were 30.3 (1.6) for the control run and 28.0 (4.1) after placebo. The percentage fall was attenuated by pretreatment with all concentrations of nedocromil sodium to 12.8 (2.8), 11.2 (2.1), 12.8 (2.1), and 14.1 (3.5) for the 0.5, 5, 10, and 20 mg/ml concentrations respectively (p less than 0.001). There were no significant differences between the different nedocromil concentrations. Mean plasma concentrations of nedocromil were proportional to dose. Thus concentrations of nebulised nedocromil sodium that ranged from 0.5 to 20 mg/ml gave a similar degree of protection (50-60%) against exercise induced asthma. This appears to be the maximum protection that can be achieved with nedocromil sodium and is similar to the protection obtained with 4 mg nedocromil administered by metered dose aerosol.
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Patel KR, Semel L, Clauss RH. Routine revascularization with resection of infected femoral pseudoaneurysms from substance abuse. J Vasc Surg 1989; 10:358. [PMID: 2778900 DOI: 10.1016/0741-5214(89)90453-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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Patel KR, Cortes LE, Semel L, Sharma PV, Clauss RH. Bullet embolism. THE JOURNAL OF CARDIOVASCULAR SURGERY 1989; 30:584-90. [PMID: 2674155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Bullet embolism is a rare complication of vascular trauma. During the last ten years we have treated six patients with bullet embolism. Three patients had inferior vena caval injuries with embolizations of the bullets to the heart or pulmonary arteries. Two had infrarenal aortic injuries with embolization to vessels of the lower extremities. One patient with a shotgun injury to the superficial femoral artery and vein had both arterial and venous embolizations. The site of vascular penetration was repaired in all six patients. All peripheral arterial bullet emboli were removed except for an asymptomatic shotgun pellet in the peroneal artery. One bullet was removed from a right atrium and another from a proximal pulmonary artery. Emboli in the distal pulmonary artery branches were left undisturbed in two patients. All six patients survived without any complications. A 14-year review of the literature is presented in order to emphasize some important features of this rare pathology.
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Farley RD, Patel KR. A microcomputer-based respiratory heat exchange facility for use in the diagnosis of thermally induced asthma. Proc Inst Mech Eng H 1989; 203:43-8. [PMID: 2712952 DOI: 10.1243/pime_proc_1989_203_006_01] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Exercise-induced asthma is prevalent in many asthmatics and during the winter months can be exacerbated by cold air inhalation. A laboratory facility was required to permit early diagnosis of cold air sensitivity in these patients. This paper describes the development of a modular air conditioning system to produce a range of inhalative thermal burdens and the microcomputer interfacing to measure the rate of airway heat loss imposed. A single-stage refrigerator was built capable of cooling 150 l/min air to -25 degrees C. This was also used to generate dry ambient temperature air by rewarming the chilled air supply. An air humidifier was developed based upon natural convection and evaporation. It was capable of raising 150 l/min ambient air to 37 degrees C, 100 per cent relative humidity. In two pilot studies of 18 asthmatics it was found that the rate of respiratory heat exchange could be correlated with the magnitude of post exertional bronchoconstriction (lung dysfunction) and that exercise-induced asthma could be minimized by attenuating the rate of airway heat loss.
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Hulks G, Patel KR. The effect of inhaled ouabain on bronchomotor tone and histamine responsiveness in asthmatic patients. PULMONARY PHARMACOLOGY 1989; 2:161-2. [PMID: 2562473 DOI: 10.1016/0952-0600(89)90041-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
We have studied the effect of inhaled ouabain on resting bronchomotor tone and histamine responsiveness in eight asthmatic patients in an attempt to clarify the role of Na/K ATPase in airway reactivity. Doses ranged from 50 micrograms to 5000 micrograms and were given in a placebo controlled, double blind manner. Baseline FEV1 was recorded prior to inhalation and at intervals up to 30 min thereafter. At 30 min, a histamine provocation test was performed and results expressed as that concentration producing a 20% fall in FEV1. Maximum fall in FEV1 was not significantly different between placebo or any dose of ouabain, ranging from 4.3%-8.2% (p greater than 0.06) nor was histamine reactivity altered significantly (geometric mean range 0.17 mg-0.29 mg [p greater than 0.2]). Unlike animal studies therefore, we have been unable to demonstrate any effect of Na/K ATPase inhibition on airway reactivity in vivo.
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Albazzaz MK, Patel KR, Shakir S, Dargie HJ, Reid JM. Effect of inhaled leukotriene C4 on cardiopulmonary function. THE AMERICAN REVIEW OF RESPIRATORY DISEASE 1989; 139:188-93. [PMID: 2912339 DOI: 10.1164/ajrccm/139.1.188] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The changes in transcutaneous oxygen saturation (SaO2%) and airway responses to inhaled histamine and leukotriene C4 (LTC4) were examined in 10 asthmatic patients, and the effect of inhaled LTC4 (16 nmol) on cardiopulmonary hemodynamics was examined in seven nonasthmatic patients undergoing diagnostic cardiac catheterization. In asthmatic patients, LTC4 produced oxygen desaturation on two occasions. At a lower dose (2.0 nmol) LTC4 produced a marked fall in SaO2% that lasted less than 15 min and occurred in the absence of significant bronchoconstriction as measured by changes in FEV1, FEF25-75, and SGaw. At a higher cumulative dose (7 nmol), LTC4 caused prolonged oxygen desaturation with slow recovery and this was associated with significant bronchoconstriction. In contrast, histamine inhalation produced a single response with a fall in both FEV1 and SaO2% of short duration. The dose-response characteristics of LTC4 and histamine on oxygen desaturation in asthmatic patients appear to differ significantly and probably are dependent on relative sensitivities of pulmonary vascular and bronchial smooth muscle to these agonists. A single inhaled dose of LTC4 in nonasthmatic subjects produced a marked drop in PaO2 with significant increase in AaPO2, and this was associated with a mean (SEM) decrease in FEV1 of 14% (2.5) from the baseline. The mean cardiac output fell by 15% (3.4) without significant changes in blood pressure and heart rate. There was no electrocardiographic evidence of myocardial ischemia.(ABSTRACT TRUNCATED AT 250 WORDS)
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Farley RD, Patel KR. Comparison of air warming in the human airway with a thermodynamic model. Med Biol Eng Comput 1988; 26:628-32. [PMID: 3256756 DOI: 10.1007/bf02447502] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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Patel KR, Semel L, Clauss RH. Routine revascularization with resection of infection femoral pseudoaneurysms from substance abuse. J Vasc Surg 1988; 8:321-8. [PMID: 3047444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Infected femoral artery pseudoaneurysms in narcotic addicts present challenging management options. Our policy of routine revascularization is based on the concern that a high rate of amputations must follow ligation and resection alone or with selective delayed revascularization. Fifteen of 16 patients with infected pseudoaneurysms of femoral arteries, treated with resection and bypass grafts, were observed from 1 to 44 months. Obturator bypass grafts were used in 10 patients, iliac-femoral grafts in three, axillopopliteal in one, and right external iliac crossover to left popliteal in one patient. One limb, unsalvageable at presentation, was amputated primarily, along with resection of pseudoaneurysm and femoral artery ligation, without bypass grafting. One iliac-femoral graft became infected and then thrombosed 4 months after operation. Unsuitable distal arteries and impending necrosis led to above-knee amputation. One late failure among 15 revascularization attempts (7%) is significantly lower than the 11% to 33% amputation rates reported in the literature with resection of pseudoaneurysm alone and delayed selective revascularization. The other 14 patients had functioning limbs without claudication or rest pain. Our experience indicates that revascularization at the time of resection of infected pseudoaneurysm offers better prospects for limb salvage.
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Patel KR, Peers E. Felodipine, a new calcium antagonist, modifies exercise-induced asthma. THE AMERICAN REVIEW OF RESPIRATORY DISEASE 1988; 138:54-6. [PMID: 3202400 DOI: 10.1164/ajrccm/138.1.54] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Recently, calcium antagonists have been reported to have a clinically beneficial effect in patients with asthma. Felodipine is a new calcium antagonist of the dihydropyridine group with a high selectivity for arteriolar smooth muscle; it is under clinical investigation for the treatment of hypertension. In this double-blind, randomized crossover trial in 9 patients, the effect of 10 mg felodipine in oral solution on exercise-induced asthma was compared with a placebo on separate days. The FEV1 was at least 80% of the predicted normal value, with variation between study days of less than 10%. Heart rate, blood pressure, and FEV1 were measured before and at 15 and 30 min after each treatment. The exercise test consisted of steady state running at submaximal work loads for 6 to 8 min and started at 30 min after treatments. FEV1 was measured at 1, 2, 5, 10, 15, and 30 min after the end of exercise. The predrug baseline FEV1 values were comparable on the 2 days of the study, and felodipine had no effect on the resting lung function. The mean percentage fall in FEV1 (SEM) after exercise with placebo was 27.0 (4.5)%, and with felodipine it was 13.5 (3.7)%. The difference between felodipine and placebo was statistically significant. While receiving felodipine, the resting heart rate was increased by 15%, with a tendency to lower systolic and diastolic blood pressures. The heart rate after exercise was higher during felodipine treatment than during placebo treatment. One patient receiving placebo and 7 receiving felodipine noted a transient headache. Two patients receiving felodipine also noticed lightheadedness after exercise.(ABSTRACT TRUNCATED AT 250 WORDS)
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