Tuula Kurki

Noninvasive continuous blood pressure measurement from the finger: optimal measurement conditions and factors affecting reliability.

We recorded finger arterial blood pressure (FINAP) in 50 male patients during various types of surgical operations. Three different types of cuffs were used on four fingers of each patient. Measurements were made by the arterial volume-clamp method of Penaz. The FINAP measurements were compared with pressure data obtained ipsilaterally from a radial artery catheter-transducer system (intraarterial pressure [IAP]) to find optimal recording conditions and to document factors affecting FINAP readings. The thumb, with a specially designed cuff, gave the most accurate results. The mean FINAP- IAP difference for the thumb was −4.8 mm Hg for systolic pressure, 1.49 mm Hg for diastolic pressure, and 0.29 mm Hg for mean pressure. The differences were statistically significant for systolic and diastolic pressure but not for mean pressure. The regression slope for thumb systolic FINAP/IAP was 0.979, that for thumb diastolic FINAP/IAP was 0.963, and that for mean thumb FINAP/IAP was 0.996, whereas the intercepts were 7.499 for systolic pressure, 0.802 for diastolic pressure, and 0.083 for mean pressure. The correlation coefficients were 0.945 (systolic), 0.884 (diastolic), and 0.949 (mean). The correlation coefficients with the other fingers ranged from 0.502 to 0.922 for systolic pressure, 0.757 to 0.932 for diastolic pressure, and 0.767 to 0.892 for mean pressure. The slopes for the various finger-cuff combinations ranged from 0.537 to 0.996, and the intercepts ranged from 0.083 to 32.387 from mean pressure. In 3 patients (6%) the FINAP measurement was not possible because of insufficient peripheral circulation. In 9 other patients (18%) the FINAP measurements were not accurate during some periods of time.In 5 of those 9 patients the difficulties were related to arterial cannulation and began immediately after cannulation. In 1 of those 5 patients the FINAP subsequently decreased dramatically after the onset of phenylephrine infusion because of peripheral vasoconstriction and diminished blood flow. In the 4 other patients the FINAP readings were accurate at the beginning of anesthesia but later decreased out of proportion to changes in IAP. These periods were associated with one-lung ventilation. The FINAP accurately reflects systemic arterial pressure. Measurements from the thumb fitted with a specially designed cuff approximate IAP best. Factors affecting peripheral circulation must be taken into consideration when this device is used in the monitoring of FINAP.

Predictors of pulse oximetry data failure

Background Pulse oximeters have been reported to fail to record data in 1.12-2.50% of cases in which anesthesia records were handwritten. There is reason to believe that these may be underestimates. Computerized anesthesia records may provide insight into the true incidence of pulse oximetry data failures and factors that are associated with such failures. Methods The current study reviewed case files of 9,203 computerized anesthesia records. Pulse oximetry data failure was defined as the presence of at least one continuous gap in data greater or equal to 10 min in duration in a case. A multivariate logistic regression model was used to identify predictors of pulse oximetry data failure, and a modified case-control method was used to determine whether extremes of blood pressure and hypothermia during the procedure were associated with pulse oximetry data failure. Results The overall incidence of cases that had at least one continuous gap of greater or equal to 10 min in pulse oximetry data was 9.18%. The independent preoperative predictors of pulse oximetry data failure were ASA physical status 3, 4, or 5 and orthopedic, vascular, and cardiac surgery. Intraoperative hypothermia, hypotension, hypertension, and duration of procedure were also independent risk factors for pulse oximetry data failure. Conclusions Pulse oximetry data failure rates based on review of computerized records were markedly greater than those previously reported. Physical status, type of surgery, and intraoperative variables were risk factors for pulse oximetry data failure. Regulations and expectations regarding pulse oximetry monitoring should reflect the limitations of the technology.

Evaluation of the relationship between preoperative risk scores, postoperative and total length of stays and hospital costs in coronary bypass surgery

OBJECTIVES Several risk indices have been developed for the prediction of postoperative mortality and morbidity in coronary artery bypass operations, in which the risk scores are currently recorded as routine praxis. The aim of the present study was to determine whether the risk scores can be used to predict the hospital (LOS) and postoperative (POS) lengths of stay and total costs among coronary artery bypass graft (CABG) patients. METHODS All first-time CABG patients (n=2104) treated at Helsinki University Central Hospital during 1997-1998 were preoperatively scored using the Cleveland Clinic preoperative model. A multivariate analysis was used to evaluate the effects of the risk scores on the LOS and POS and total costs. RESULTS The mean preoperative risk score for the patients was 1.69. The increase in preoperative risk score was associated with an increase in the LOS (0.8 days by point), and POS (with 0.55 days by point). An age over 74 years increased the LOS by an extra day. The mean total cost for the CABG procedure was 8750 euros (SD 4430 euros). The costs increased as the risk score increased. Compared with the zero risk score, a score value of 2 was associated with a 1300 euros increase in total cost and a score value of over 6 was associated with an over 7000 euros cost increase. On average, the costs increased by 6980 euros (80%) for one major complication and by 935 euros (10%) in the elderly (>74 years of age). CONCLUSIONS The results show that increasing risk scores were associated with longer postoperative hospital lengths of stay (POS and LOS) and with increased total costs. An age over 74 years appears to be an independent risk factor in increased POS, LOS and total cost. These results may help to estimate the impact of the preoperative risk profile on the resource requirement in CABG surgery.

Emergency and elective coronary artery bypass grafting: comparisons of risk profiles, postoperative outcomes, and resource requirements

OBJECTIVE To investigate the association between preoperative risk factors and postoperative outcomes in emergency and elective coronary artery bypass graft (CABG) patients and to quantify resource requirements. DESIGN Retrospective database review. SETTING New York State SPARCS database. PARTICIPANTS Data from 4,001 emergency and 7,489 elective CABG patients were evaluated retrospectively. INTERVENTIONS Data were compared between groups using chi-squares, t tests, and logistic regression analysis. MEASUREMENTS AND MAIN RESULTS Preoperatively, 47.1% of patients in the emergency group had unstable angina and 34.1% had acute myocardial infarction compared with 33.9% and 15.2% in the elective group, respectively (p < 0.0001). There were no marked differences in the preoperative noncardiac risk factors between groups. The mortality rate was 4.7% in the emergency group and 2.6% in the elective group (p < 0.0001). The emergency group had more postoperative cardiac complications (18.3% v 8.3%, p < 0.0001). The length of hospital stay in the emergency group was 17.5 +/- 15.8 days (median 14 days) compared with 12.9 +/- 15.1 days (median 9 days) in the elective group (p < 0.00001). Total hospital charges in the emergency and elective groups were 46,700 US dollars +/- 42,400 US dollars (median 35,600 US dollars ) and 34,800 US dollars +/- 36,400 US dollars (median 26,500 US dollars) (p < 0.00001), respectively. The median total cost was 26,300 US dollars for emergency and 19,600 US dollars for elective group (p < 0.00001). CONCLUSION Patients undergoing emergency CABG had greater postoperative morbidity and mortality, longer LOS, and higher total costs than patients undergoing elective surgery. This difference is predictable on the basis of preoperative cardiac risk factors. Emergency operations have a major impact on the rates of morbidity, mortality, and use of resources.

Single lung allotransplantation in pigs : a morphologic study of tissue preservation with modified euro-collins and fluorocarbon solutions

In the present study the functional and morphologic effects of two pulmoplegic solutions are evaluated. Single left-lung allotransplantation with ligation of the right pulmonary artery was performed in 15 piglets (13-20 kg). The lungs were preserved after donor prostaglandin E-1 treatment with single pulmonary artery flush with either modified Euro-Collins solution (mECS) (9 pigs) or oxygenated fluorocarbon emulsion (FC-43) (6 pigs) and transplanted after 6-hr storage in cold Physiosol solution. Tidal volumes of 15 ml/kg x fr (18) with 40% inspired oxygen were used for ventilation during reperfusion. Function of the transplanted lung was monitored for 4 hr postoperatively by determining pa CO2 and pa O2 levels from arterial samples and by noninvasive monitoring of end-tidal CO2 values and arterial oxygen saturations. Sequential morphologic changes in pulmonary artery flow surface and lung tissue were studied after 6-hr storage and 4-hr reperfusion, using light, scanning, and transmission electron microscopy (LM, SEM, TEM). There was no mortality. After transplantation the mECS group experienced significant hypoxia and hypercarbia and had low end-tidal CO2 values as signs of defective oxygenation and gas exchange, whereas the FC-43 group was normoxic and normoventilated without disturbed elimination of carbon dioxide. After storage and reperfusion, LM showed signs of increased vascular permeability and reperfusion damage--more evident in the mECS group compared with the FC-43 group--while the lymphoid cell population was more intensely activated in the latter group. Electron microscopy after storage showed good overall preservation of structures in both groups. After reperfusion preservation of pulmonary artery flow surface and lung tissue was estimated to be moderate in the mECS group, whereas it was good-to-moderate in the FC-43 group by SEM (NS). TEM of lung tissue, however, showed significantly better-preserved alveolar epithelial lining in the FC-43 group compared with the mECS group. In conclusion, oxygenated fluorocarbon (FC-43) pulmoplegia gave better functional and morphologic preservation of lung grafts compared with modified Euro-Collins solution.

Single-Lung Allotransplantation in Pigs Following Donor Pretreatment with Intravenous Prostaglandin E-1: Morphologic Changes after Preservation and Reperfusion

Single left lung allotransplantation with ligation of the right pulmonary artery was performed on 11 pigs after donor pretreatment with prostaglandin E-1 and pulmonary artery flush with modified Euro-Collins solution. Sequential morphologic changes in pulmonary artery flow surface and lung structure were studied after 6-hour storage and after 4-hour reperfusion, using light microscopy and scanning and transmission electron microscopy. Morphologic observations were compared with functional changes. After 6-hour preservation slight degenerative changes were found in the pulmonary artery flow surface and changes in lung tissue suggestive of increased vascular permeability and edema. During 4-hour reperfusion the changes progressed. Preservation was in general moderate. Lung tissue showed vascular congestion and slight inflammation. Localized areas of reperfusion damage could adjoin near-normal looking alveoli. Oxygenation and gas exchange, though low in the beginning of reperfusion, tended to improve during the reperfusion period. The method was concluded to afford good morphologic preservation of the graft after 6-hour storage, and moderately good morphologic and functional preservation after 4-hour reperfusion.

Isolated gonococcal ascending aorta aneurysm

We present a very rare case of an acute septic infection and vegetative mycotic aneurysm caused by Neisseria gonorrhoeae in a 52-year old male. The aortic valve was bicuspid and calcified. He was successfully treated by the resection of the ascending aorta and the aortic valve with a replacement by separate prostheses, followed by 2 weeks of intravenous antibiotic therapy. The patient was followed up 18 months postoperatively with no signs of reinfection.