Operating unit time use is associated with anaesthesia type in below-knee surgery in adults.

BACKGROUND: Peripheral nerve blocks could reduce the operating unit and theatre time spent on high-risk patients who are particularly vulnerable to complications of general anaesthesia or have medications that prevent application of central neuraxial blocks. METHODS: Medical record data of 617 and 254 elderly adults undergoing below-knee surgery in Jorvi and Meilahti hospitals (Helsinki University Hospital) between January 2010 and December 2012 were used to investigate the influence of anaesthetic technique on operating theatre times and on operating unit times using flexible parametric survival models. We report operating theatre and unit exit ratios (i.e. hazard ratios but using ratios of exit rates) for different types of anaesthesia. RESULTS: Adjusted analyses: In Jorvi Hospital, anaesthesia type was associated with large initial differentials in operating theatre times. The theatre exit ratios remained lower for general anaesthesia and central neuraxial blocks compared to peripheral nerve blocks until 30 min. In Meilahti Hospital, anaesthesia type did not influence theatre time, but was the best predictor of operating unit times. Compared to peripheral nerve blocks, the exit ratio remained lower for general anaesthesia until five operating unit hours in both hospitals and for central neuraxial blocks until 1 h in Meilahti Hospital and until 3 h in Jorvi Hospital. Holding area was used more in Jorvi Hospital compared to Meilahti Hospital. CONCLUSION: Peripheral nerve block anaesthesia reduces time spent in the operating unit and can reduce time spent in the operating theatre if induced in holding area outside of theatre.

Dexamethasone decreases oxycodone consumption following osteotomy of the first metatarsal bone: a randomized controlled trial in day surgery.

BACKGROUND: Dexamethasone may improve multimodal pain management following painful orthopedic day surgery procedures, and decrease the need for post-operative opioids. We hypothesized that dexamethasone would reduce the need for oxycodone after surgical correction of hallux valgus. METHODS: Sixty patients planned to undergo unilateral osteotomy of the first metatarsal as a day surgery procedure were randomized to receive pre-operatively and 24 h afterwards, orally either dexamethasone 9 mg or placebo. For pain medication, paracetamol and oxycodone capsules for rescue medication were given. The study ended on the evening of the third post-operative day (POD). The primary endpoint was the cumulative oxycodone consumption. Secondary endpoints were maximal pain scores before oxycodone intake and daily oxycodone doses. In addition, adverse effects were documented. RESULTS: Twenty-five patients in both groups completed the study. The total median (range) oxycodone consumption during the study period was 45 (0-165) mg in the dexamethasone group and 78 (15-175) mg in the placebo group (P=0.049). The major differences in oxycodone consumption were seen on PODs 0-1. In the dexamethasone group, patients reported significantly lower pain scores on PODs 0-1, and significantly less nausea on POD 1. On PODs 2-3 no differences were seen. However, at 2 weeks post-operatively, patient satisfaction to drug therapy did not differ - in both groups 81% would have chosen the same medication again. CONCLUSION: Oral dexamethasone combined with paracetamol significantly reduced total oxycodone consumption following surgical correction of hallux valgus.

Day surgery in Finland: a prospective cohort study of 14 day-surgery units.

BACKGROUND: Day surgery is an established practice for elective operative care, and is considered safe and cost-effective in several procedures and for several patients. At present, day-surgery accounts for approximately 50% of elective surgery in Finland. The aim of this study was to prospectively describe the present situation at Finnish day-surgery units, focusing on the quality of care. METHODS: Fourteen large- to medium-sized day surgery and short-stay units were recruited, and all patient cases performed during a 2-month study period were registered and analyzed. Quality of care was assessed by analyzing the rates and reasons for overnight admission, readmission, reoperation, and cancellations. Satisfaction of care was inquired from day-surgery patients during a 2-week period. Head anesthesiologists were interviewed about functional policies. RESULTS: Of 7915 reported cases, 84% were day surgery. Typically, several specialties were represented at the units, with orthopedics accounting for nearly 30% of all day-surgery procedures. Patient selection criteria were in line with the present-day recommendations, although the proportion of older patients and the ASA physical status 3 patients were still relatively low. The rate of unplanned overnight admissions was 5.9%. Return hospital visits were reported in 3.7% and readmissions in 0.7% of patients 1-28 days post-operatively. Patient satisfaction was high. CONCLUSION: Along with the growing demand for day surgery, Finnish public hospitals have succeeded in providing good-quality care, and there still seems to be potential to increase the share of day surgery. Easily accessible benchmarking tools are needed for quality control and learning from peers.

Mortality in diabetic patients undergoing non-cardiac surgery: a 7-year follow-up study.

BACKGROUND: The prognosis of diabetic patients after non-cardiac surgery remains controversial. This study was designed to compare the long-term mortality between diabetic and non-diabetic control patients undergoing non-cardiac surgery and to evaluate the possible risk factors. METHODS: We investigated 274 consecutive diabetic patients and 282 non-diabetic control patients who underwent non-cardiac surgery within 1 year in a tertiary care hospital in Finland. The control group was matched for the same type of operations. Patients were followed for up to 7 years on average. The main outcome measure was mortality within 7 years. RESULTS: Mortality both in the short-term postoperatively (< or =21 days) and in the long-term (up to 87 (1/2) months) was significantly higher in the diabetic patients compared with the non-diabetic group: 3.5 vs. 0% (P<0.05) and 37.2 vs. 15% (P<0.00001), respectively. The major causes of death among diabetic subjects were diseases of the cardiovascular system (56.8%) compared with non-diabetic patients (18.6%), P<0.0001. We found that diabetes mellitus per se is not a risk factor for post-operative mortality but a combination of variables had a significant effect on both short- and long-term mortality. CONCLUSION: Diabetic patients undergoing non-cardiac surgery had a significantly higher incidence of short-term post-operative and long-term mortality compared with non-diabetic subjects. We propose a model of predictors of death among diabetic individuals undergoing non-cardiac surgery within a 7-year follow-up. The majority of deaths were associated with cardiovascular diseases.

Surgical stress index as a measure of nociception/antinociception balance during general anesthesia.

BACKGROUND: No validated monitoring method is available for evaluating the nociception/antinociception balance. We assessed the surgical stress index (SSI), computed from finger photoplethysmographic waveform amplitudes and pulse-to-pulse intervals, in patients undergoing shoulder surgery under general anesthesia (GA) and interscalene plexus block and in patients with GA only. METHODS: In this prospective, randomized study in 26 patients, increased blood pressure (BP) or heart rate, movement, and coughing were considered to be signs of intraoperative nociception and were treated with alfentanil. GA was maintained with desflurane aiming at a State Entropy level of 50. Photoplethysmographic waveforms were collected from the contra-lateral arm to the surgery and SSI values from 0 (no surgical stress) to 100 (maximal surgical stress) were calculated off-line. RESULTS: Two minutes after skin incision, SSI had not increased in the plexus group and was lower in the plexus group (38 +/- 13) compared with the controls (58 +/- 13, P<0.005). Among the controls, 1 min before alfentanil administration, the SSI value was higher than during periods of adequate antinociception, 59 +/- 11 vs. 39 +/- 12 (P<0.01). The total cumulative need for alfentanil was higher in controls (2.7 +/- 1.2 mg) compared with the plexus group (1.6 +/- 0.5 mg; P=0.008). Tetanic stimulation to the ulnar region of the hand increased SSI significantly only among the patients with plexus block not covering the site of the stimulation. CONCLUSION: SSI values were lower in patients with plexus block covering the sites of nociceptive stimuli. In detecting nociceptive stimuli, SSI had better performance than heart rate, BP, or response entropy.

Pulmonary vascular resistance before and after cardiopulmonary bypass. The effect of PaCO2.

To examine whether CPB influences pulmonary vascular sensitivity to CO2, we compared the effect of slight induced hypocarbia and hypercarbia on pulmonary circulation before and after CPB in ten mechanically ventilated patients undergoing CABG. Hypocarbia was produced by increasing tidal volume slightly and hypercarbia was then induced by adding CO2 to the inspired gas mixture. In another ten patients, hypercarbia was produced after CPB by decreasing ventilator rate and the cardiopulmonary responses to hypercarbia, produced by the two methods of CO2 elevation, were compared. Slight respiratory acidosis induced by CO2 inhalation did not change PVR before CPB but effected a 50 percent increase after CPB. Hypercarbia induced by alveolar hypoventilation after CPB increased PVR by 40 percent. During the increased CO2 production after hypothermic CPB, pulmonary vasoconstriction would be expected to occur and impair right ventricular performance. Therefore, tight control of PaCO2 with appropriate adjustment of ventilatory support is mandatory.

Renal and vascular effects of atrial natriuretic factor during cardiopulmonary bypass.

STUDY OBJECTIVE: To evaluate renal and vasodilator effects of synthetic atrial natriuretic factor (ANF) in patients undergoing cardiopulmonary bypass (CPB) with special reference to the applicability of ANF as a diuretic and natriuretic. DESIGN: The study consisted of two parts. The first 15 consecutive patients in a university hospital received a pharmacologically effective bolus dose of 100 micrograms ANF, as demonstrated previously in other studies, or placebo. After analysis of the bolus data (see "Results" section below), the 12 subsequent patients were administered ANF 50 micrograms as a constant 30-min infusion at a rate of 1.67 micrograms/min or placebo. PATIENTS: The patients were scheduled for elective coronary artery bypass grafting operation. There was no evidence of congestive heart failure in any patient, and no one had an endocrine or renal disorder. INTERVENTIONS: After achievement of hypothermia (29 to 30 degrees C of rectal temperature) during CPB, a bolus dose of ANF 100 micrograms was given or an infusion of ANF 1.67 micrograms/min for 30 min, ie, a total dose of 50 micrograms was started. The control patients received placebo correspondingly. Intravenous fluids were administered according to a predetermined scheme. MEASUREMENTS AND MAIN RESULTS: For the pharmacologic effects of ANF urine volume, urinary sodium excretion and mean arterial pressure (MAP) were measured. Only three of the eight patients receiving the bolus dose of ANF had a diuretic and natriuretic response to the drug, and the responses were significantly related (r = 0.91, p less than 0.05 and r = 0.98, p less than 0.001, respectively) to the prevailing MAP at the time of the bolus administration. The bolus dose of ANF decreased MAP significantly (p less than 0.001 vs placebo) from 65 +/- 6 (mean +/- SEM) to 55 +/- 6 mm Hg within 5 min. The infusion of ANF did not affect MAP, but it increased urine output (16.1 +/- 5.0 ml/min, when the data obtained during the 30-min infusion and a 30-min period after the infusion were combined) and urinary sodium excretion (1,651 +/- 514 microEq/min) significantly (p less than 0.05 and p less than 0.01, respectively) as compared with the corresponding values of 3.3 +/- 1.1 ml/min and 386 +/- 141 microEq/min after placebo. CONCLUSIONS: Prevailing arterial pressure is an important determinant of the diuretic and natriuretic activity of synthetic ANF in patients undergoing CPB. A low-dose infusion of ANF (50 micrograms within 30 min) provides diuresis and natriuresis without significant changes in MAP in these patients.

Successful treatment of ARDS with two doses of synthetic surfactant.

A 50-year-old man with adult respiratory distress syndrome (ARDS) was successfully treated with synthetic surfactant. The therapy rapidly improved the respiratory function; it also increased the release of endogenous surfactant. Synthetic surfactant may thus be of value in the treatment of ARDS.

Customized prediction models based on APACHE II and SAPS II scores in patients with prolonged length of stay in the ICU.

OBJECTIVE: To study customized APACHE II and SAPS II models in predicting hospital death in patients with a prolonged length of stay in the ICU. DESIGN: Prospectively collected database. SETTING: Thirteen ICUs with 5-10 beds in Finnish secondary referral hospitals. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: The database was collected between 1994 and 1999 and included 23,953 ICU admissions. In order to customize the original APACHE II and SAPS II models and to validate the models, the database was randomly divided into customization data ( n=12,064) and into validation data ( n=11,889). Logistic regression analysis was used for customization. As the length of the ICU stay was prolonged, the calibration and discrimination of both customized models worsened gradually in the validation data. Patients whose ICU stay lasted 7 days or longer (1,312 patients) consumed more than one half of all ICU days and TISS-points. Among these patients, goodness-of-fit statistics was 221.5 and 306.3 ( P<0.0001 for both) and the areas under ROC curve 0.65 and 0.62 for the customized APACHE and SAPS models, respectively. The models underestimated the risk of death in the low range and overestimated it in the high range of predicted mortality. On the other hand, both models discriminated well between survivors and non-survivors if the ICU stay was 2 days or less. CONCLUSIONS: Despite customization, the predictive models may not support clinical decision-making in those patients who require a high share of resources. More relevant instruments are needed for the prediction of outcome of patient groups who consume the major part of ICU resources.

Atrial pressure and hormonal and renal responses to acute cardiac tamponade.

The effect of acute cardiac tamponade on atrial pressures, plasma atrial natriuretic factor concentration and renin activity, and renal water and electrolyte excretion was studied in pigs loaded intravenously with hydroxyethyl starch and maintained on a continuous intravenous infusion of isotonic saline solution. Saline solution was infused into the pericardial space in 6 anesthetized pigs until a predetermined decrease of 20% in mean arterial pressure was achieved. Another 6 sham-treated pigs served as controls. Tamponade increased atrial intracavitary pressures but decreased atrial transmural (distending) pressures. These changes in atrial pressures were reversed after release of tamponade. Changes in plasma atrial natriuretic factor concentration correlated positively with changes in atrial transmural pressures. Tamponade increased plasma renin activity and decreased urine flow and renal sodium and potassium excretion, and release of tamponade reversed these changes. Thus, the tamponade-induced reduction in atrial distention is associated with hormonal changes, which may contribute to the reductions in diuresis and natriuresis observed in this connection.

Intra-institutional prediction of outcome after cardiac surgery: comparison between a locally derived model and the EuroSCORE.

OBJECTIVE: To construct models for predicting mortality, morbidity and length of intensive care unit (ICU) stay after cardiac surgery and to compare the performance of these models with that of the EuroSCORE in two independent validation databases. METHODS: Clinical data on 4592 cardiac surgery patients operated between 1992 and 1996 were retrospectively collected. In order to derive predictive models and to validate them, the patient population was randomly divided into a derivation database (n=3061) and a validation database (n=1531). Variables that were significant in univariate analyses were entered into a backward stepwise logistic regression model. The outcome was defined as mortality within 30 days after surgery, predefined morbidity, and the length of ICU stay lasting >2 days. In addition to the retrospective database, the models were validated also in a prospectively collected database of cardiac surgical patients operated in 1998-1999 (n=821). The EuroSCORE was tested in two validation databases, i.e. the retrospective and prospective one. Hosmer-Lemeshow goodness-of-fit was used to study the calibration of the predictive models. Area under the receiver operating characteristic (ROC) curve was used to study the discrimination ability of the models. RESULTS: The overall mortality in the retrospective and the prospective data was 2 and 1%, and morbidity 22 and 18%, respectively. The created predictive models fitted well in the validation databases. Our models and the EuroSCORE were equally good in discriminating patients. Thus, in the prospective validation database, the mean areas under the ROC curve for our models and for the EuroSCORE were similar, i.e. 0.84 and 0.77 for mortality, 0.74 and 0.74 for morbidity, and 0.81 and 0.79 for the length of intensive care unit stay lasting for 2 days or more, respectively. CONCLUSIONS: Our models and the EuroSCORE were equally good in discriminating the patients in respect to outcome. However, our model provided also well calibrated estimation of the probability of prolonged ICU stay for each patient. As was originally suggested, the EuroSCORE may be an appropriate tool in categorizing cardiac surgical patients into various subgroups in interinstitutional comparisons. Our models may have additive value especially in resource allocation and quality assurance purposes for local use.