Biomedical subjects

R Pokela

Publications and source records attributed to R Pokela.

43 records · Page 3Linked to original sources

PubMed1978

Intraoperative changes in coronary resistance during aortic valve replacement.

Coronary vascular resistance was investigated in 10 patients undergoing aortic valve replacement using continuous constant-pressure coronary perfusion at 32 degrees C. After coronary flow was initiated, resistance was low but increased steadily until it reached a certain resting level. The plateau was attained faster after a short period of anoxia than after a longer period. The initial postischemic resistance was dependent on the duration preceding anoxia, being of the same magnitude after short and moderate periods of anoxia but significantly higher after a long period. This resistance difference between the groups lasted for the whole perfusion. The total coronary resistance and flow reached a plateau in 30 minutes, while resistance increased threefold but flow decreased to half of the initial postanoxia flow. Our results indicate the importance of initiating coronary perfusion soon after aortic cross-clamping to avoid increase in the initial vascular resistance and subsequent inadequate myocardial flow.

Adult↗

PubMed1978

Myocardial reactive hyperemia caused by initial myocardial anoxia during aortic valve replacement.

Reactive hyperemic response of individual coronary arteries and of the whole heart to anoxia during coronary cannulation was investigated in 10 patients undergoing aortic valve replacement. Reactive hyperemic response in man is identical to that reported in experimental investigations. The duration of hyperemic response was dependent on the length of the preceding period of anoxia; the longer the period of anoxia, the more prolonged was the hyperemic response. No significant collateral circulation between the coronary arteries could be demonstrated during prolonged anoxia of an individual coronary artery. Blood flow debt was almost always overpaid, but the repayment percentage decreased with the lengthening of the anoxic period, being 460 percent after a short period of anoxia (less than or equal to 2 minutes), 230 percent after an anoxic period of moderate length (3 to 5 minutes), and only 160 percent after a long period of anoxia (greater than or equal to 7 minutes). The total mean repayment of blood flow debt of the whole heart was 195 percent.

Adult↗

PubMed1978

Effect of initial myocardial anoxia on coronary flow during aortic valve replacement.

Flow to the right and left coronary arteries was recorded continuously during aortic valve replacement using continous constant-pressure coronary perfusion at 32 degrees C in 13 patients. The initially high coronary flow decreased gradually until a certain level, the so-called resting flow level, was reached and stabilized there as long as perfusion temperature remained unchanged. At 32 degrees C, resting flow was about 50% of the peak hyperaemic flow. The length of preceding anoxia had a significant effect on the duration of reactive hyperaemic response. After a short anoxic period, resting flow level was reached in about 3 min, after moderate period in 15 min and after long anoxia in 35 min, respectively.

Adolescent↗

PubMed1977

Myocardial protection by continuous coronary perfusion during aortic valve replacement.

The coronary perfusion system used at Oulu University Central Hospital is described and the importance of physiological coronary perfusion stressed. Our method of protecting the myocardium from ischemic injury during aortic valve replacement included the following: phasic constant-pressure coronary perfusion, maintenance of coronary perfusion pressure larger than or equal to 80 mmHg, maintenance of the heart in a beating, empty, oxygenated state, and the use of the largest possible coronary canula. Under these circumstances, autoregulation of the coronary vascular bed was maintained. When small coronary cannulae were used a significant pressure drop occured across the tubing system, especially at high flow rates. Flow measurements recorded by an on-line electromagnetic flowmeter proved reliable.

Adolescent↗

PubMed1976

Hiatal hernia repair.

128 patients operated on for hiatal hernia are reported. The follow-up study consisted of 102 patients, 16 with paraoesophageal and 86 with axial hiatal hernia. The mean follow-up time was 4 1/2 years, range 1-11 years. In our experience cineradiographic studies bring abnormalities to light more readily because this kind of study is repeatable compared with conventional techniques based on fluoroscopy. Four different methods of operation were used in this study. The recurrence rate was as follows: Nissen fundoplication 13%, both anterior 180 degrees fundoplication and Lortat-Jacobs procedure 38%, and Nissen fundoplication combined to vagotomy and pyloroplasty 54%. Postoperative complications occurred in 9%. There was no hospital mortality. The authors prefer the abdominal to the transthoracic approach because many patients had other intra-abdominal, surgically easily correctable condition. If the transthoracic operation is indicated, as in a very obese patient or in a patient with a secondary short oesophagus, intra-abdominal disease must have been excluded preoperatively. In the treatment of axial hiatal hernia the best operative method has not yet been agreed upon, but in our hands the Nissen fundoplication yielded the best results.

Adult↗

PubMed1975

Haemophilus influenzae as a cause of salpingitis.

A case is reported of acute unilateral salpingitis, the cause of which was Haemophilus influenzae cultured from a pus sample taken from the infected Fallopian tube during laparotomy. The significance of the findings is discussed with reference to the literature.

Acute Disease↗

PubMedDate not supplied

Computed tomography and mediastinoscopy in the assessment of resectability of lung cancer.

In order to assess the potential of computed tomography (CT) of the mediastinum and mediastinoscopy in the staging of lung cancer, 125 patients were examined. Of these, 104 underwent thoracotomy, at which there was no evidence of mediastinal tumour involvement in 79 while 25 patients had signs of tumour spread. The sensitivity and specificity of CT were 87.0 per cent and 95.8 per cent, respectively, in the detection of direct tumour extension with a mediastinal mass. When lymph node enlargement was the sole finding, CT did not provide any differentiation between benign and malignant lymphadenopathy. The mediastinal involvement was inaccessible on mediastinoscopy in 18 cases (72%). Despite the surperior sensitivity of CT it was often difficult to determine whether direct tumour infiltration of mediastinal structures had occurred. It was concluded that CT is necessary for screening the entire mediastinum and, when it reveals no evidence of mediastinal tumour spread, mediastinoscopy will yield no further information. Mediastinoscopy will help to correctly identify accessible mediastinal lymph node involvement of the superior mediastinum and to define the mediastinal tumour invasion in doubtful cases.

Aged↗