Effect of aspirin in vascular surgery in patients from a randomized clinical trial (POISE-2).

BACKGROUND: In the POISE-2 (PeriOperative ISchemic Evaluation 2) trial, perioperative aspirin did not reduce cardiovascular events, but increased major bleeding. There remains uncertainty regarding the effect of perioperative aspirin in patients undergoing vascular surgery. The aim of this substudy was to determine whether there is a subgroup effect of initiating or continuing aspirin in patients undergoing vascular surgery. METHODS: POISE-2 was a blinded, randomized trial of patients having non-cardiac surgery. Patients were assigned to perioperative aspirin or placebo. The primary outcome was a composite of death or myocardial infarction at 30 days. Secondary outcomes included: vascular occlusive complications (a composite of amputation and peripheral arterial thrombosis) and major or life-threatening bleeding. RESULTS: Of 10 010 patients in POISE-2, 603 underwent vascular surgery, 319 in the continuation and 284 in the initiation stratum. Some 272 patients had vascular surgery for occlusive disease and 265 had aneurysm surgery. The primary outcome occurred in 13·7 per cent of patients having aneurysm repair allocated to aspirin and 9·0 per cent who had placebo (hazard ratio (HR) 1·48, 95 per cent c.i. 0·71 to 3·09). Among patients who had surgery for occlusive vascular disease, 15·8 per cent allocated to aspirin and 13·6 per cent on placebo had the primary outcome (HR 1·16, 0·62 to 2·17). There was no interaction with the primary outcome for type of surgery (P = 0·294) or aspirin stratum (P = 0·623). There was no interaction for vascular occlusive complications (P = 0·413) or bleeding (P = 0·900) for vascular compared with non-vascular surgery. CONCLUSION: This study suggests that the overall POISE-2 results apply to vascular surgery. Perioperative withdrawal of chronic aspirin therapy did not increase cardiovascular or vascular occlusive complications. Registration number: NCT01082874 ( http://www.clinicaltrials.gov).

Normal saline versus a balanced crystalloid for goal-directed perioperative fluid therapy in major abdominal surgery: a double-blind randomised controlled study.

BACKGROUND: This double-blind randomised controlled trial investigated whether normal saline or a balanced crystalloid has distinct effects on vasopressor use in patients undergoing major abdominal surgery. METHODS: Patients received either normal saline 0.9% or an acetate-buffered crystalloid for intraoperative volume replacement in a goal-directed fashion. The primary outcome was need for vasopressors; the secondary outcomes were the total dose of catecholamines, total perioperative fluid, and unplanned intensive care admissions. RESULTS: This study was terminated early for safety reasons. A total of 60 out of the planned 240 patients were randomized. Thirty patients received normal saline and 30 patients received the balanced crystalloid, with a total volume of 3427 (2732-4130) ml and 3144 (1673-4926), respectively. The normal-saline group developed hyperchloraemic metabolic acidosis. More patients needed vasopressors for circulatory support in the normal-saline group compared with the buffered crystalloid group (97% vs 67%, respectively; P=0.033). The median weight and anaesthesia duration-adjusted dose of norepinephrine were 0.11 (0.00-0.45) ng kg-1 min-1 and 0.00 (0.00-0.00) kg-1 min-1 in the normal-saline and balanced-crystalloid groups, respectively (P=0.003). Cox regression revealed that the need for vasopressors was related to a high volume of administered fluid, normal-saline resuscitation, and lower mean arterial blood pressure. There was no difference between the groups in total perioperative fluid and unplanned intensive-care-unit admissions. Between-group differences in the duration of anaesthesia did not influence the necessity for a vasopressor. CONCLUSIONS: Compared with patients receiving a balanced crystalloid, normal saline in patients undergoing major abdominal surgery was associated with an increased need for vasopressor support. This should be interpreted in view of the large volume of fluid resuscitation and the small sample size because of the preliminary termination of the study. CLINICAL TRIAL REGISTRATION: EudraCT 2014-004867-19, NCT 02414555.

Evaluation of stroke volume variation obtained by arterial pulse contour analysis to predict fluid responsiveness intraoperatively.

BACKGROUND: Fluid management guided by oesophageal Doppler monitor has been reported to improve perioperative outcome. Stroke volume variation (SVV) is considered a reliable clinical predictor of fluid responsiveness. Consequently, the aim of the present trial was to evaluate the accuracy of SVV determined by arterial pulse contour (APCO) analysis, using the FloTrac/Vigileo system, to predict fluid responsiveness as measured by the oesophageal Doppler. METHODS: Patients undergoing major abdominal surgery received intraoperative fluid management guided by oesophageal Doppler monitoring. Fluid boluses of 250 ml each were administered in case of a decrease in corrected flow time (FTc) to <350 ms. Patients were connected to a monitoring device, obtaining SVV by APCO. Haemodynamic variables were recorded before and after fluid bolus application. Fluid responsiveness was defined as an increase in stroke volume index >10%. The ability of SVV to predict fluid responsiveness was assessed by calculation of the area under the receiver operating characteristic (ROC) curve. RESULTS: Twenty patients received 67 fluid boluses. Fifty-two of the 67 fluid boluses administered resulted in fluid responsiveness. SVV achieved an area under the ROC curve of 0.512 [confidence interval (CI) 0.32-0.70]. A cut-off point for fluid responsiveness was found for SVV > or =8.5% (sensitivity: 77%; specificity: 43%; positive predictive value: 84%; and negative predictive value: 33%). CONCLUSIONS: This prospective, interventional observer-blinded study demonstrates that SVV obtained by APCO, using the FloTrac/Vigileo system, is not a reliable predictor of fluid responsiveness in the setting of major abdominal surgery.

A new instrument for pain assessment in the immediate postoperative period.

Perceptual-cognitive impairment after general anaesthesia may affect the ability to reliably report pain severity with the standard visual analog scale (VAS). To minimise these limitations, we developed 'PAULA the PAIN-METER' (PAULA): it has five coloured emoticon faces on the forefront, it is twice as long as a standard VAS scale, and patients use a slider to mark their pain experience. Forty-eight postoperative patients rated descriptive pain terms on PAULA and on a standard VAS immediately after admission and before discharge from the postanaesthesia care unit. Visual acuity was determined before both assessments. The values obtained with PAULA showed less variance than those obtained with the standard VAS, even at the first assessment, where only 23% of the patients had regained their visual acuity. Furthermore, the deviations of the absolute VAS values in individual patients for each descriptive pain term were significantly smaller with PAULA than with the standard VAS.

Effect of brain magnetic resonance imaging on body core temperature in sedated infants and children.

BACKGROUND: Children undergoing magnetic resonance imaging (MRI) under sedation are at risk of hypo- or hyperthermia. The effect of brain MRI at differing magnetic field strengths on body core temperature in sedated infants and young children has not been reported previously. METHODS: Two groups of 38 infants and children (aged 1 month to 6 yr 5 months) underwent brain MRI for different indications related to cerebral diseases, at 1.5 Tesla (T) and 3 T MRI units, respectively. All patients received deep sedation comprising midazolam, nalbuphine, and propofol. Pre-scan and post-scan temperatures were measured at the right tympanic and at rectal sites. No active warming devices were used during the procedures. RESULTS: Body core temperature measurements were similar between right tympanic and rectal site before and after the scans. After 1.5 T scans, the median (IQR) increase from pre-scan to post-scan tympanic temperature was 0.2 degrees C (0.1-0.3), and the median (IQR) rectal temperature increase was 0.2 degrees C (0-0.3) (P<0.001). After 3 T scans, the median (IQR) tympanic temperature increase was 0.5 degrees C (0.4-0.7), and the median (IQR) rectal temperature increase was 0.5 degrees C (0.3-0.6) (P<0.001). CONCLUSIONS: Body core temperature increased significantly during 1.5 and 3 T examinations; this increase was more profound during 3 T MRI. Patient heating occurred despite minimal efforts to reduce passive heat loss under sedation and without the use of warming devices.

Propofol-based sedation regimen for infants and children undergoing ambulatory magnetic resonance imaging.

BACKGROUND: Propofol is widely used for infants and children requiring sedation for magnetic resonance imaging. However, increased doses of propofol may quickly lead to an unintended deep sedation and respiratory depression. Thus, an appropriate low dosage, which nevertheless ensures sufficient sleep for successful magnetic resonance imaging (MRI) completion, would probably minimize respiratory adverse events. We investigated the safety and efficacy of a low-dose propofol-based sedation regimen in a broad age range of children. METHODS: We investigated 500 infants and children, prospectively. Premedication consisted of i.v. midazolam 0.1 mg kg(-1). Sedation was induced with i.v. nalbuphine 0.1 mg kg(-1) and propofol 1 mg kg(-1), and maintained with propofol 5 mg kg(-1) h(-1). Outcome measures were induction time, sedation time, recovery time, need for additional sedation, respiratory events, cardiovascular events, paradoxical reactions, and sedation failure. RESULTS: Data were obtained from 53 infants and 447 children. Median (IQR) age was 5.3 (4.5, 6.1) yr and body weight was 19.3 (16.5, 24.7) kg. The induction time was 2 (1, 2) min, sedation time 55 (45, 65) min, and recovery time 8 (8, 9) min. Additional sedation was necessary in 11 patients (2.2%), mild respiratory events occurred in five patients (1%). All MRI examinations could be completed without paradoxical reaction or sedation failure. CONCLUSION: This sedation regimen provides the shortest induction time so far described, a rare demand for additional sedation, a low incidence of respiratory events, and a rapid recovery.

Effects of continuous remifentanil administration on intra-operative subcutaneous tissue oxygen tension.

Surgical stress response markedly increases sympathetic nerve activity and catecholamine concentrations. This may contribute to peripheral vasoconstriction, reduced wound perfusion and subsequent tissue hypoxia. Opioids are known to depress the hypothalamic-adrenal response to surgery in a dose-dependent manner. We tested the hypothesis that continuous remifentanil administration produces improved subcutaneous tissue oxygen tension compared to fentanyl bolus administration. Forty-six patients undergoing major abdominal surgery were randomly assigned to receive either fentanyl bolus administration or continuous remifentanil infusion. Mean subcutaneous tissue oxygen values over the entire intra-operative period were significantly higher in the remifentanil group, when compared to the fentanyl group: 8 (2) kPa vs 6.7 (1.5) kPa, % CI difference: - 2.3 kPa to - 0.3 kPa, p = 0.013. Continuous intra-operative opioid administration may blunt vasoconstriction caused by surgical stress and adrenergic responses more than an equi-effective anaesthetic regimen based on smaller-dose bolus opioid administration.

Laparoscopic surgery impairs tissue oxygen tension more than open surgery.

BACKGROUND: Wound infection remains a common and serious complication after colonic surgery. Although many colonic operations are performed laparoscopically, it remains unclear whether this has any impact on the incidence of wound infection. Subcutaneous tissue oxygenation is an excellent predictor of surgical wound infection. The impact of open and laparoscopic colonic surgery on tissue oxygenation was compared. METHODS: Fifty-two patients undergoing elective open and laparoscopic left-sided colonic resections were evaluated in a prospective observational study. Anaesthesia management was standardized and intraoperative arterial partial pressure of oxygen was kept at 150 mmHg in both groups. Oxygen tension was measured in the subcutaneous tissue of the right upper arm. RESULTS: At the start of surgery subcutaneous tissue oxygen tension (PsqO(2)) was similar in both groups (mean(s.d.) 65.8(17.2) and 63.7(23.6) mmHg for open and laparoscopic operations respectively; P = 0.714). Tissue oxygen remained stable in the open group, but dropped significantly in the laparoscopic group during the course of surgery (PsqO(2) after operation 53.4(12.9) and 45.5(11.6) mmHg, respectively; P = 0.012). CONCLUSION: Laparoscopic colonic surgery significantly decreases PsqO(2), an effect that occurs early in the course of surgery. As tissue oxygen tension is a predictor of wound infection, these results may explain why the risk of wound infection after laparoscopic surgery remains higher than expected.

First experience with fiberoptically directed wire-guided endobronchial blockade in severe pulmonary bleeding in an emergency setting.

We report the first use of a new wire-guided endobronchial blocker in a critical respiratory situation caused by localized pulmonary bleeding. During emergency management, it became increasingly difficult to ventilate a multiple-trauma patient with a conventional single-lumen tube because of massive bleeding through the bronchus of the left lower lobe. Using the Arndt endobronchial blocker set (William Cook Europe A/S; Bjaeverskor, Denmark), we were able to prevent the spread of hemorrhaging and achieved effective ventilation and marked improvement in gas exchange. This new device allows the effective blockade of an isolated lobe under direct bronchoscopy to buy time for further intervention.

Tracheal intubation and cervical spine excursion: direct laryngoscopy vs. intubating laryngeal mask.

Until recently, the most appropriate technique of intubating a patient with a cervical spine injury has been the subject of debate. Tracheal intubation by means of the intubating laryngeal mask (Fastrach), a modified conventional laryngeal mask airway, seems to require less neck manipulation. The aim of this study was to compare the excursion of the upper cervical spine during tracheal intubation using direct laryngoscopy with that during intubation via the laryngeal mask (Fastrach), by examination of lateral cervical spine radiographs in healthy young patients. The intubating laryngeal mask (Fastrach) caused less extension (at C1-2 and C2-3) than intubation by direct laryngoscopy. Direct laryngoscopy is still the fastest method to secure an airway provided no intubating difficulties are present. However, in trauma patients requiring rapid sequence induction and in whom cervical spine movement is limited or undesirable, the intubating laryngeal mask (Fastrach) is a safe and fast method by which to secure the airway.

Aggressive warming reduces blood loss during hip arthroplasty.

UNLABELLED: We evaluated the effects of aggressive warming and maintenance of normothermia on surgical blood loss and allogeneic transfusion requirement. We randomly assigned 150 patients undergoing total hip arthroplasty with spinal anesthesia to aggressive warming (to maintain a tympanic membrane temperature of 36.5 degrees C) or conventional warming (36 degrees C). Autologous and allogeneic blood were given to maintain a priori designated hematocrits. Blood loss was determined by a blinded investigator based on sponge weight and scavenged cells; postoperative loss was determined from drain output. Results were analyzed on an intention-to-treat basis. Average intraoperative core temperatures were warmer in the patients assigned to aggressive warming (36.5 degrees +/- 0.3 degrees vs 36.1 degrees +/- 0.3 degrees C, P< 0.001). Mean arterial pressure was similar in each group preoperatively, but was greater intraoperatively in the conventionally warmed patients: 86+/-12 vs 80+/-9 mm Hg, P<0.001. Intraoperative blood loss was significantly greater in the conventional warming (618 mL; interquartile range, 480-864 mL) than the aggressive warming group (488 mL; interquartile range, 368-721 mL; P: = 0.002), whereas postoperative blood loss did not differ in the two groups. Total blood loss during surgery and over the first two postoperative days was also significantly greater in the conventional warming group (1678 mL; interquartile range, 1366-1965 mL) than in the aggressively warmed group (1,531 mL; interquartile range, 1055-1746 mL, P = 0.031). A total of 40 conventionally warmed patients required 86 units of allogeneic red blood cells, whereas 29 aggressively warmed patients required 62 units (P = 0.051 and 0.061, respectively). We conclude that aggressive intraoperative warming reduces blood loss during hip arthroplasty. IMPLICATIONS: Aggressive warming better maintained core temperature (36.5 degrees vs 36.1 degrees C) and slightly decreased intraoperative blood pressure. Aggressive warming also decreased blood loss by approximately 200 mL. Aggressive warming may thus, be beneficial in patients undergoing hip arthroplasty.

Osteoarthrosis after the Max Lange procedure for unstable shoulders.

Thirty-four patients were followed for a mean of 14.4 years after the Max Lange operation for instability of the shoulder. This procedure consists of an anterior capsulorraphy with lateralisation of the subscapularis tendon and the insertion of a bone block at the inferior and anterior part of the glenoid. The Rowe score showed 87% good and excellent results. External rotation and abduction were significantly limited as compared to the normal side. Radiographs revealed osteoarthrosis in 47%. Double contrast computed tomography in 18 cases showed a bony defect in the anterior and inferior part of the humeral head in 12 who had significantly limited external rotation as compared to those without the defect. Lateralisation of the subscapularis tendon with limitation of external rotation may lead to increased contact stress and shear forces at the anterior rim of the glenoid which contributes to the development of osteoarthrosis.

Helal metatarsal osteotomy for the treatment of metatarsalgia: a critical analysis of results.

We reviewed the results of treatment of 114 feet in 96 patients with pressure metatarsalgia treated with a metatarsal osteotomy performed according to the technique of Helal. Clinical examination was performed according to a standardized evaluation questionnaire using the American Orthopaedic Foot and Ankle Society Lesser Metatarsophalangeal-Interphalangeal Scale. The results were correlated with number of metatarsal osteotomies, the length of the follow up, the age of the patient, and type of additional procedures performed. Sixty-one percent of the patients rated the operation as excellent or good. Patient age and number of osteotomies did not influence the results; however, the length of time following surgery and associated Keller-Brandes resection arthroplasty influenced the outcome negatively. There was a high incidence of increased transfer of weight to adjacent metatarsals. We concluded that the Helal type metatarsal osteotomy is unlikely to predictably achieve symptom relief over a long period.