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Biomedical subjects

C Arén

Publications and source records attributed to C Arén.

At least 19 recordsLinked to original sources
PubMed2000

Coagulase-negative staphylococci and sternal infections after cardiac operation.

BACKGROUND: Coagulase negative staphylococci (CoNS) have been recognized as important pathogens in nosocomial infections, especially in connection with implanted foreign materials. In cardiac operation they are among the most common pathogens isolated from infected sternal wounds. The definition of the infection is very important. In this study we focus on deep postoperative chest infections. METHODS: By studying 33 infected patients retrospectively and comparing them to 33 matched uninfected controls, we studied the characteristics and costs of the infections. RESULTS: Typical for these infections is the late and insidious onset, and that the infections initially give only minor symptoms such as pain, redness, and serous secretion. We found the following risk factors for infection: number of preoperative days in a hospital, the total length of the operation, and if the patient had undergone an early reoperation due to causes other than infection. This kind of infection more than doubled the hospital costs for the patients affected. CONCLUSIONS: Coagulase negative staphylococci are the most important pathogens in deep postoperative infections in this material. They cause infections that are difficult to recognize since they give only discrete symptoms and start well after the patients leave the hospital. The risk factors for patients with CoNS infections are mostly associated with a long exposure to the hospital environment. The treatment is often difficult and costly because of multiresistant bacteria and frequent need for repeated surgical revisions.

Cardiac Surgical Procedures↗
PubMed2000

Lack of effect of synthetic pericardial substitute on right ventricular function after coronary artery bypass surgery. An echocardiographic and magnetic resonance imaging study.

Abnormal right heart function after cardiac surgery is a well-known finding. Inadequate preservation during the operation and restricted cardiac motion due to pericardial adhesions have been proposed as underlying mechanisms. This study focuses on the impact of a pericardial substitute implantation on right ventricular function, using echocardiography and magnetic resonance imaging. A test group of six patients (mean age 54 years) was examined before surgery, and 4-15 days and 5-9 months after coronary artery bypass surgery, where the pericardium was closed with a biodegradable pericardial patch. A group of 11 patients (mean age 63 years) in whom the pericardium was left open served as controls. Tricuspid annulus motion was markedly decreased, abnormal septal motion was present and decreased systolic to diastolic ratio in the vena cava superior flow was present in all patients in both groups one week after surgery. At the late follow-up, all patients still had decreased tricuspid annulus motion, while 17% of the patients in the test group and 22% of the patients in the control group (ns) demonstrated normal septal motion. We conclude that closing the pericardium with a biodegradable patch does not affect the postoperative changes in right heart function normally seen after open-heart surgery.

Aged↗
PubMed1998

Video-assisted thoracic surgery (VATS) lobectomy: the initial Swedish experience.

BACKGROUND: This study was performed to evaluate the technical feasability and validity of video-assisted pulmonary lobectomy using simultaneous stapling of the hilar structures. METHODS: Between December 1995 and July 1997, 30 video-assisted thoracic non-rib spread simultaneously stapled lobectomies (VATS(n)SSL) were performed. RESULTS: Fourteen males and 16 females underwent 9 right upper, 4 right middle, 5 right lower, 4 left upper, and 8 left lower lobectomies for 15 adenocarcinomas, 7 squamous cell carcinomas, 4 benign and 2 metastatic lesions, 1 carcinoid and 1 mucosa-associated lymphoid tissue-lymphoma. All patients with primary lung carcinoma had peripheral lesions, 13 were T1 and 9 were T2 lesions. Lesions ranged from 1.0 cm to 4.0 cm, averaging 2.2 cm. Results of 10 cervical mediastinoscopies were negative. Two patients had positive nodes at postoperative examination. Operating time for the series averaged 128 minutes, for the first 10 patients 146 minutes, and for the last 10 patients 106 minutes. There was no surgical mortality and no transfusion. Perioperative bleeding averaged 185 mL. Two procedures were converted to open thoracotomy. Hospitalization averaged 4.4 days for the entire group. CONCLUSION: Video-assisted thoracic surgical non-rib spread simultaneously stapled lobectomy is a technically feasible and safe procedure. Therapeutic outcomes for resected neoplasms need to be evaluated in long-term follow-up studies.

Aged↗
PubMed1998

Cerebral complications after coronary artery bypass and heart valve surgery: risk factors and onset of symptoms.

OBJECTIVES: Cerebral complications continue to be a major cause of morbidity after cardiac surgery. Earlier studies have mainly focused on intraoperative events, but symptoms may also occur later in the postoperative period. The purpose of this study was to determine the incidence and risk factors of focal neurologic complications and timing of cerebral symptoms. DESIGN: A retrospective study. SETTING: Linköping University Hospital. PARTICIPANTS: Two thousand four hundred eighty patients who underwent cardiac surgery from 1992 to 1995. INTERVENTIONS: Standard cardiopulmonary bypass (CPB) technique was used in all patients. Anticoagulant treatment included heparin and patients with coronary artery surgery were also administered acetylsalicylic acid and valve-surgery patients received warfarin or dicumarol. MEASUREMENTS AND MAIN RESULTS: Seventy-five patients (3%) had focal neurologic deficits and/or confusion postoperatively. In 32 patients (43%), the onset was not intraoperative but occurred later in the postoperative period. The lowest incidence of cerebral complications was found in patients who underwent single-valve replacement (1.2%) and the highest incidence was found in patients who underwent combined procedures (valve and coronary artery surgery; 7.6%). Patients greater than 70 years of age had a complication rate of 4.1% compared with 2.5% in patients aged 70 years and less (p < 0.05). The incidence of diabetes mellitus was 11.4% in the entire series, but was more common (18.7%; p < 0.05) in patients with cerebral symptoms. Also, 5.9% of all patients had a history of cerebrovascular disease compared with 14.7% (p < 0.01) of patients with cerebral complications. CONCLUSION: Cerebral complications may be delayed after cardiac surgery, suggesting causes of cerebral damage other than intraoperative events. Valve-surgery patients had the lowest incidence and patients with combined procedures had the highest incidence of cerebral complications. Advanced age, diabetes mellitus, and preexisting cerebrovascular disease increased the risk.

Adolescent↗
PubMed1995

Intra- and postoperative cerebral complications of open-heart surgery.

A consecutive series of 1400 patients who had undergone open-heart surgery was retrospectively reviewed concerning postoperative cerebral dysfunction. The 30-day mortality was 1.6%. Forty-one patients (2.9%) showed signs of cerebral dysfunction, which proved fatal in seven cases. Neurologic symptoms were observed immediately after surgery in 14 patients, suggesting intraoperative damage. In 20 others there was an interval between surgery and the onset of cerebral symptoms, which in 12 cases were preceded by supraventricular tachycardia. Computed tomographic scans were performed on 27 patients and showed recent brain infarction in 22. No bleeding was found. At follow-up 34 of the 41 patients were alive, 21 of them with neurologic sequelae and 13 reporting complete recovery. Nineteen of the 34 survivors experienced no diminution of quality of life. Since half of the cerebral complications occurred postoperatively, more aggressive prevention and management of supraventricular tachyarrhythmia and anticoagulation therapy should be considered.

Adolescent↗
PubMed1994

Nurses' notes on sleep patterns in patients undergoing coronary artery bypass surgery: a retrospective evaluation of patient records.

In this study, patient records from 80 male patients, aged 43-76, undergoing first-time coronary artery bypass surgery were evaluated with regard to nurses' documentation on sleep during the first four postoperative days. This documentation was classified into descriptions of quality and quantity of sleep. Notations on sleep were found in 69-86% of patient records each night, and was most common the second night. Descriptions of both quality and quantity of sleep occurred in only 12 out of 320 patient-nights. Notes regarding duration of sleep were found for 146 patient-nights (45.6%), of which 103 (32.2%) contained sleep disturbances. Information on quality of sleep was given for 116 patient-nights (36.3%), with only 38 patient-nights (11.9%) of sleep disturbances. For 72 patient-nights, documentation of the patients' sleep was lacking. Frequent awakening was the most common sleep disturbances noted during all but the first night, when continuous awakening dominated. We conclude that the nurses' documentation regarding sleep and sleep disturbances varied over a wide range, with a mixture of quantitative and qualitative information, and that more structured descriptions are needed.

Adult↗
PubMed1990

Atrial rate-responsive pacing in sinus node disease.

Patients with sinus node disease (SND) who are unable to achieve an adequate increase in heart rate during exercise are candidates for atrial rate-responsive pacing (AAI-R). We have implanted 40 AAI-R systems in SND patients with an average follow-up of 12.5 +/- 8 (range 3-30) months. All the patients received an activity-sensing pulse generator (Activitrax, Medtronic or Sensolog, Siemens-Pacesetter) with a single atrial lead. Only patients with an intraoperative AV nodal block cycle-length above 100 beats min-1 were included. During follow-up, one patient was observed to have transient asymptomatic 2:1 AV-block during sleep. No patient developed persistent AV-block or chronic atrial fibrillation. Twelve patients with persistent chronotropic incompetence were assigned for a randomized double-blind crossover study, comparing exercise treadmill capacity in AAI-R with conventional atrial inhibited pacing (AAI). During AAI-R pacing the maximum heart rate during exercise was 120 +/- 1 beats min-1 compared with 97 +/- 21 beats min-1 during AAI pacing (P less than 0.01). The average exercise time increased from 11.2 +/- 2 min during AAI-pacing to 13.4 +/- 3 min during AAI-R pacing (P less than 0.01). AAI pacing should be considered for patients with SND and chronotropic incompetence.

Cardiac Pacing, Artificial↗
PubMed1987

Comparison of two protocols for heparin neutralization by protamine after cardiopulmonary bypass.

Twenty patients undergoing cardiac operations were randomly assigned to two protocols for heparin neutralization by protamine after cardiopulmonary bypass. In all patients protamine chloride was given at a ratio of 1 unit of protamine to 1 unit of injected heparin. In Group I (10 patients) all protamine was infused within 10 minutes after termination of cardiopulmonary bypass. Group II (10 patients) received 75% of the calculated protamine dose within 10 minutes after termination of bypass and the remainder after transfusion of all blood in the heart-lung machine. Plasma heparin levels were significantly lower in Group II 5 minutes after transfusion of all blood in the heart-lung machine and were 0.13 units/ml (standard deviation 0.04) in Group I and 0.06 units/ml (standard deviation 0.05) in Group II (p less than 0.001) 60 minutes after bypass. Activated partial thromboplastin time mirrored the changes in plasma heparin, whereas activated clotting time (Hemochron) was too insensitive to detect these low plasma heparin levels. We conclude that the two-dose protocol resulted in more complete heparin neutralization than the one-dose protocol.

Cardiopulmonary Bypass↗
PubMed1986

Cerebral blood flow and metabolism during cardiopulmonary bypass with special reference to effects of hypotension induced by prostacyclin.

Cerebral blood flow and metabolism of oxygen, glucose, and lactate were studied in 43 patients undergoing aortocoronary bypass. Twenty-five patients received prostacyclin infusion, 50 ng per kilogram of body weight per minute, during cardiopulmonary bypass (CPB), and 18 patients served as a control group. Regional cerebral blood flow (CBF) was studied by intraarterially injected xenon 133 and a single scintillation detector. Oxygen tension, carbon dioxide tension, oxygen saturation, glucose, and lactate were measured in arterial and cerebral venous blood. Mean arterial blood pressure decreased during hypothermia and prostacyclin infusion to less than 30 mm Hg. The regional CBF was, on average, 22 (standard deviation [SD] 4) ml/100 gm/min before CPB. It increased in the control group during hypothermia to 34 (SD 12) ml/100 gm/min, but decreased in the prostacyclin group to 15 (SD 5) ml/100 gm/min. It increased during rewarming in the prostacyclin group. After CPB, regional CBF was about 40 ml/100 gm/min in both groups. The cerebral arteriovenous oxygen pressure difference decreased more in the control group than in the prostacyclin group during hypothermia. The cerebral metabolic rate of oxygen decreased in both groups from approximately 2 ml/100 gm/min to about 1 ml/100 gm/min during hypothermia, increased again during rewarming, and after CPB was at the levels measured before bypass in both groups. There was no difference between the groups in regard to glucose and lactate metabolism.

Adult↗
PubMed1985

Effects of prostacyclin infusion on renal function during cardiopulmonary bypass.

Infusion of prostacyclin inhibits platelet activation during cardiopulmonary bypass (CPB) but also results in systemic arterial hypotension. Therefore, the effects of CPB and prostacyclin on renal function were studied in 36 male patients undergoing aortocoronary bypass. Nineteen patients (Group 1) received prostacyclin, 50 ng per kilogram of body weight per minute, during CPB, and 17 patients (Group 2) served as controls. There was pronounced hypotension in Group 1 only. Urine production during CPB averaged 88 +/- 140 ml and 2,306 +/- 1,112 ml in Groups 1 and 2, respectively. No patient had renal failure. Glomerular filtration rate (GFR), as measured by clearance of chromium 51-labeled ethylenediaminetetraacetic acid, was increased in Group 1 from 86 +/- 14 to 99 +/- 22 ml/1.73 m2/min (p less than 0.05) the day after operation, but remained unchanged in Group 2 (81 +/- 15 to 82 +/- 21 ml/1.73 m2/min). The increased GFR in Group 1 can be regarded as an expected adaptation to the change in body fluids after CPB. Therefore, the unchanged GFR in Group 2 must be regarded as caused by insufficient adaptation or impaired renal function. Proximal tubular function was evaluated by determination of beta 2-microglobulin in urine. In both groups, urinary beta 2-microglobulin and the ratio of urinary beta 2-microglobulin to urinary creatinine were increased the day after operation. The hypotension in Group 1 did not exacerbate the damage to tubular function.

Aged↗