Peripheral perfusion index stratifies risk in patients with intraoperative anemia: A multicentre cohort study.

STUDY OBJECTIVE: Evidence for red blood cell (RBC) transfusion thresholds in the intraoperative setting is limited, and current perioperative recommendations may not correspond with individual intraoperative physiological demands. Hemodynamics relevant for the decision to transfuse may include peripheral perfusion index (PPI). The objective of this prospective study was to assess the associations of PPI and hemoglobin levels with the risk of postoperative morbidity and mortality. DESIGN: Multicenter cohort study. SETTING: Bispebjerg and Hvidovre University Hospitals, Copenhagen, Denmark. PATIENTS: We included 741 patients who underwent acute high risk abdominal surgery or hip fracture surgery. INTERVENTIONS: No interventions were carried out. MEASUREMENTS: Principal values collected included measurements of peripheral perfusion index and hemoglobin values. METHODS: The study was conducted using prospectively obtained data on adults who underwent emergency high-risk surgery. Subjects were categorized into high vs. low subgroups stratified by pre-defined PPI levels (PPI: > 1.5 vs. < 1.5) and Hb levels (Hb: > 9.7 g/dL vs. < 9.7 g/dL). The study assessed mortality and severe postoperative complications within 90 days. MAIN RESULTS: We included 741 patients. 90-day mortality was 21% (n = 154), frequency of severe postoperative complications was 31% (n = 231). Patients with both low PPI and low Hb had the highest adjusted odds ratio for both 90-day severe postoperative complications (2.95, [1.62-5.45]) and 90-day mortality (3.13, [1.45-7.11]). A comparison of patients with low PPI and low Hb to those with high PPI and low Hb detected significantly higher 90-day mortality risk in the low PPI and low Hb group (OR 8.6, [1.57-162.10]). CONCLUSION: High PPI in acute surgical patients who also presents with anemia was associated with a significantly better outcome when compared with patients with both low PPI and anemia. PPI should therefore be further investigated as a potential parameter to guide intraoperative RBC transfusion therapy.

Comparing the effects of continuous positive airway pressure via mask or helmet interface on oxygenation and pulmonary complications after major abdominal surgery: a randomized trial.

The risk of pulmonary complications is high after major abdominal surgery but may be reduced by prophylactic postoperative noninvasive ventilation using continuous positive airway pressure (CPAP). This study compared the effects of intermittent mask CPAP (ICPAP) and continuous helmet CPAP (HCPAP) on oxygenation and the risk of pulmonary complications following major abdominal surgery. Patients undergoing open abdominal aortic aneurysm repair or pancreaticoduodenectomy were randomized (1:1) to either postoperative ICPAP or HCPAP. Oxygenation was evaluated as the partial pressure of oxygen in arterial blood fraction of inspired oxygen ratio (PaO2/FIO2) at 6 h, 12 h, and 18 h postoperatively. Pulmonary complications were defined as X-ray verified pneumonia/atelectasis, clinical signs of pneumonia, or supplementary oxygen beyond postoperative day 3. Patient-reported comfort during CPAP treatment was also evaluated. In total, 96 patients (ICPAP, n = 48; HCPAP, n = 48) were included, and the type of surgical procedure were evenly distributed between the groups. Oxygenation did not differ between the groups by 6 h, 12 h, or 18 h postoperatively (p = 0.1, 0.08, and 0.67, respectively). Nor was there any difference in X-ray verified pneumonia/atelectasis (p = 0.40) or supplementary oxygen beyond postoperative day 3 (p = 0.53). Clinical signs of pneumonia tended to be more frequent in the ICPAP group (p = 0.06), yet the difference was not statistically significant. Comfort scores were similar in both groups (p = 0.43), although a sensation of claustrophobia during treatment was only experienced in the HCPAP group (11% vs. 0%, p = 0.03). Compared with ICPAP, using HCPAP was associated with similar oxygenation (i.e., PaO2/FIO2 ratio) and a similar risk of pulmonary complications. However, HCPAP treatment was associated with a higher sensation of claustrophobia.

High-dose preoperative glucocorticoid for prevention of emergence and postoperative delirium in liver resection: A double-blinded randomized clinical trial substudy.

BACKGROUND: Emergence delirium (ED) and postoperative delirium (POD) are associated with increased morbidity and mortality and occur in up to one-third of patients undergoing major non-cardiac surgery, where the underlying pathogenesis is multifactorial, including increased inflammation. We aimed to assess the effect of pre-operative high- versus low-dose glucocorticoid on the occurrence of ED and POD. METHODS: This was a substudy from a randomized, double-blinded clinical trial. Patients ≥18 years, undergoing open liver resection were randomized 1:1 to high-dose (HD, 10 mg/kg methylprednisolone) or low-dose (LD, 8 mg dexamethasone) glucocorticoid and assessed for ED and POD for a maximum of 4 days during hospitalization. The 3-min Diagnostic Interview for CAM-defined delirium (3D-CAM) was used for assessment, 15 and 90 min after arrival in the post-anesthesia care unit (PACU), and subsequently once daily in the ward. RESULTS: Fifty-three patients were included in this secondary substudy (26 HD-group and 27 LD-group). ED occurred in n = 5 HD versus n = 6 LD patients 15 min after PACU arrival. At 90 min after PACU arrival, 4 patients had ED, all from LD-group, and resulted in significantly longer PACU admission, 273 versus 178 min in ED versus Non-ED patients. During the first 4 days in the ward, n = 5 patients had at least one occurrence of POD, all from LD-group. CONCLUSIONS: The primary finding of the current substudy was a lower occurrence of ED/POD in the PACU 90 min after arrival and during the first four postoperative days in patients receiving high-dose glucocorticoid compared with patients receiving low-dose glucocorticoid. The two study groups were not evenly balanced concerning known explanatory factors, i.e., age and size of surgery, which calls for larger studies to elucidate the matter.

Managing patients on direct factor Xa inhibitors with rapid thrombelastography.

The use of direct factor Xa inhibitors rivaroxaban and apixaban (XABANs) has rapidly increased; however, there is no validated test available to monitor the effect on hemostasis. This study aims to assess how hemostatic management based on the Rapid Thromboelastography (R-TEG) variable activated clotting time (ACT) of XABAN patients with ongoing bleedings or in need for acute surgical intervention, affected patient outcome. A total of 343 XABAN patients were included in the main analysis together with 50 healthy volunteers to validate the reference value for ACT. An ACT >120 s (s) was defined as having XABAN-induced coagulopathy. Sixty-five percent of the XABAN patients presented with R-TEG ACT within the normal reference. Patients with XABAN-induced coagulopathy had a significantly increased risk of severe bleeding. Significantly more patients with extra-cerebral bleeding (ECB) and ACT above 120 s were transfused with five red blood cell (RBC) units or more compared to patients with ACT at 120 s or below (17% vs. 3%, p <.05). Significantly more XABAN-patients with ACT above 120 s received pro-hemostatic intervention with prothrombin complex concentrate (PCC) when compared to those with ACT at 120 s or below (ECB: 2% vs. 8%, p =.03, intracranial hemorrhage: 25% vs. 68%, p <.00). Patients who received PCC had a higher 30- and 90-day mortality compared to the rest of the cohort (16% vs. 6%, p = .02 and 21% vs. 7%, p =.00). Patients with XABAN-induced coagulopathy as evaluated by R-TEG ACT presented with more severe bleeding and higher transfusion requirements when compared to those with ACT in the normal range. This suggests that R-TEG ACT measurement in XABAN patients with active hemorrhage or in need for acute surgery may be of clinical value.

European guidelines on perioperative venous thromboembolism prophylaxis: Day surgery and fast-track surgery.

: In recent years, day surgery and fast-track surgery have experienced a continuous increase in volume. Many procedures are now performed on an outpatient protocol, including general, orthopaedic, oncological, reconstructive or vascular surgery. The management of these patients is safe, but the incidence of venous thromboembolism in this population remains unknown. Several risk factors can be identified and stratified derived from studies of inpatient surgical management (e.g. Caprini score). Recommendations for thromboprophylaxis should be tailored from the assessment of both personal and procedure-related risk factors, although with a lack of evidence for application in outpatient management. For patients undergoing a low-risk procedure without additional risk factors, we recommend only general measures of thromboprophylaxis (early ambulation, optimal hydration) (Grade 1B). For patients undergoing a low-risk procedure with additional risk factors, or a high-risk procedure without additional risk factors, we recommend general measures of thromboprophylaxis (Grade 1B) and we suggest the administration of pharmacological prophylaxis with low molecular weight heparins (Grade 2B). For patients undergoing a high-risk procedure with additional risk factors we recommend general measures of thromboprophylaxis (Grade 1B) and pharmacological prophylaxis with low molecular weight heparins over other drugs (Grade 1B), or suggest specific mechanical measures in case of increased bleeding risk (Grade 2C). Pharmacological prophylaxis should last a minimum of 7 days (Grade 1B), although in selected cases of fast-track surgery, thromboprophylaxis could be limited to hospitalisation only (Grade 2C) and in specific cases of high-risk procedures, thromboprophylaxis could be extended for up to 4 weeks (Grade 2B).

No Effect of a Bipolar Sealer on Total Blood Loss or Blood Transfusion in Nonseptic Revision Knee Arthroplasty-A Prospective Study With Matched Retrospective Controls.

BACKGROUND: Postoperative anemia is frequent after revision of total knee arthroplasty (TKA) with reported transfusion rates up to 83%. Despite increased efforts of reducing blood loss and enhancing fast recovery within the fast-track setup, a considerable transfusion rate is still evident. The aim of this study was therefore to evaluate the effect of a bipolar sealer on blood loss and transfusion in revision TKA. METHODS: In this single-center prospective cohort study with retrospective controls, 51 patients were enrolled in a fast-track setup for revision TKA without the use of a tourniquet. Twenty-five prospectively enrolled patients received treatment with both a bipolar sealer and electrocautery, whereas 26 patients had received treatment with a conventional electrocautery only in the retrospective group. RESULTS: No significant differences were found neither for calculated blood loss, with 1397 (standard deviation, ± 452) mL in the bipolar sealer group vs 1452 (SD, ± 530) mL in the control group (P = .66), nor for blood transfusion rates of 53% and 46% (P = .89), respectively. Four controls were readmitted within 90 days follow-up. CONCLUSION: The use of a bipolar sealer in a TKA revision setting without the use of a tourniquet did not reduce blood loss or blood transfusion rates.

Combined Intra-Articular and Intravenous Tranexamic Acid Reduces Blood Loss in Total Knee Arthroplasty: A Randomized, Double-Blind, Placebo-Controlled Trial.

BACKGROUND: In total knee arthroplasty, both intravenous (IV) and intra-articular (IA) administration of tranexamic acid (TXA) have been shown to reduce blood loss in several randomized controlled trials, although routine use of systemic TXA is considerably more common. However, to our knowledge, the additional benefit of IA administration of TXA when combined with IV administration, without the use of a tourniquet, has not been previously investigated. Thus, the aim of this study was to evaluate whether combined IV and IA administration of TXA reduced total blood loss compared with IV-only administration of TXA. METHODS: In this randomized, double-blind, placebo-controlled trial, 60 patients scheduled for total knee arthroplasty were randomized to one of two interventions. The TXA IV and IA group received combined administration of TXA consisting of 1 g administered intravenously preoperatively and 3 g diluted in 100 mL of saline solution administered intra-articularly after closure of the capsule. The TXA IV and placebo group received 1 g of TXA administered intravenously only and 100 mL of saline solution administered intra-articularly. IA TXA was administrated through a needle. The primary outcome was the 24-hour calculated blood loss. Secondary outcomes were blood loss on postoperative day 2, thromboembolic complications, and transfusion rate. Blood loss was calculated by hemoglobin differences using the Gross formula. RESULTS: Data on the primary outcome were available for all 60 included patients. Baseline characteristics were comparable between the allocation groups. The mean 24-hour blood loss (and standard deviation) was 466 ± 313 mL in the TXA IV and IA group compared with 743 ± 358 mL in the TXA IV and placebo group; treatment effect (difference), 277 mL (95% confidence interval [CI], 103 to 451 mL) (p = 0.002). Second-day blood loss was 644 ± 382 mL in the TXA IV and IA group compared with 1017 ± 519 mL in the TXA IV and placebo group; treatment effect, 373 mL (95% CI, 132 to 614 mL) (p = 0.003). No thromboembolic complications were observed within 90 days postoperatively. CONCLUSIONS: The combined administration of IV and IA TXA resulted in a clinically relevant reduction in blood loss of 37% compared with IV TXA alone both at 24 hours postoperatively and on postoperative day 2. No thromboembolic complications were observed. LEVEL OF EVIDENCE: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Postoperative anemia and early functional outcomes after fast-track hip arthroplasty: a prospective cohort study.

BACKGROUND: Postoperative anemia is prevalent in fast-track hip arthroplasty (THA) where patients are mobilized and discharged early, but whether anemia impairs functional recovery after discharge has not been adequately evaluated previously. This study aimed to evaluate whether postoperative anemia influenced recovery of mobility and quality of life (Qol) during the first 2 weeks after discharge from THA. STUDY DESIGN AND METHODS: This was a prospective observational study in 122 THA patients more than 65 years of age. Mobility and Qol were assessed pre- and postoperatively by the 6-minute walk test (6MWT; primary outcome), the timed up-and-go test, and the FACT-anemia subscale. Twenty-four-hour mobility at home was assessed by activity monitoring on Days 1 to 6 after discharge. Hemoglobin (Hb) at discharge (HbD) and the Hb decrease from preoperatively (ΔHb) were compared to mobility and Qol the first 2 weeks after discharge using bivariate and multivariate linear regression. RESULTS: Mean (±SD) HbD and ΔHb values were 11.1 (±1.4) and 2.8 (±1.2) g/dL and correlated weakly to 6MWT 2 weeks after discharge (r = 0.23 and r = -0.20 respectively; p < 0.05) but HbD levels were not correlated to other mobility or Qol measures. After adjustment for preoperative patient-related factors, HbD explained 6% (95% confidence interval, 0%-9%; p < 0.05) of the variation in 6MWT recovery. CONCLUSION: Despite a weak, but significant, correlation between postoperative Hb and the recovery of 6MWT, all other mobility and Qol measures were not influenced by postoperative Hb. Thus, moderate postoperative anemia has limited impact on early postdischarge functional recovery after fast-track THA.

Oral Midodrine Hydrochloride for Prevention of Orthostatic Hypotension during Early Mobilization after Hip Arthroplasty: A Randomized, Double-blind, Placebo-controlled Trial.

BACKGROUND: Early postoperative mobilization is essential for rapid recovery but may be impaired by orthostatic intolerance (OI) and orthostatic hypotension (OH), which are highly prevalent after major surgery. Pathogenic mechanisms include an insufficient postoperative vasopressor response. The oral α-1 agonist midodrine hydrochloride increases vascular resistance, and the authors hypothesized that midodrine would reduce the prevalence of OH during mobilization 6 h after total hip arthroplasty relative to placebo. METHODS: This double-blind, randomized trial allocated 120 patients 18 yr or older and scheduled for total hip arthroplasty under spinal anesthesia to either 5 mg midodrine hydrochloride or placebo orally 1 h before mobilization at 6 and 24 h postoperatively. The primary outcome was the prevalence of OH (decrease in systolic or diastolic arterial pressures of > 20 or 10 mmHg, respectively) during mobilization 6 h after surgery. Secondary outcomes were OI and hemodynamic responses to mobilization at 6 and 24 h. RESULTS: At 6 h, 14 (25%; 95% CI, 14 to 38%) versus 23 (39.7%; 95% CI, 27 to 53%) patients had OH in the midodrine and placebo group, respectively, relative risk 0.63 (0.36 to 1.10; P = 0.095), whereas OI was present in 15 (25.0%; 15 to 38%) versus 22 (37.3%; 25 to 51%) patients, relative risk 0.68 (0.39 to 1.18; P = 0.165). At 24 h, OI and OH prevalence did not differ between groups. CONCLUSIONS: Preemptive use of oral 5 mg midodrine did not significantly reduce the prevalence of OH during early postoperative mobilization compared with placebo. However, further studies on dose and timing are warranted since midodrine is effective in chronic OH conditions.

Decreased heart rate variability responses during early postoperative mobilization--an observational study.

BACKGROUND: Intact orthostatic blood pressure regulation is essential for early mobilization after surgery. However, postoperative orthostatic hypotension and intolerance (OI) may delay early ambulation. The mechanisms of postoperative OI include impaired vasopressor responses relating to postoperative autonomic dysfunction. Thus, based on a previous study on haemodynamic responses during mobilization before and after elective total hip arthroplasty (THA), we performed secondary analyses of heart rate variability (HRV) and aimed to identify possible abnormal postoperative autonomic responses in relation to postural change. METHODS: A standardized mobilization protocol before, 6 and 24 h after surgery was performed in 23 patients scheduled for elective THA. Beat-to-beat arterial blood pressure was measured by photoplethysmography and HRV was derived from pulse wave interbeat intervals and analysed in the time and frequency domain as well as by non-linear analysis using sample entropy RESULTS: Before surgery, arterial pressures and HR increased upon standing, while HRV low (LF) and high frequency (HF) components remained unchanged. At 6 and 24 h after surgery, resting total HRV power, sample entropy and postural responses in arterial pressures decreased compared to preoperative conditions. During standing HF variation increased by 16.7 (95 % CI 8.0-25.0) normalized units (nu) at 6 h and 10.7 (2.0-19.4) nu at 24 h compared to the preoperative evaluation. At 24 h the LF/HF ratio decreased from 1.8 (1.2-2.6) nu when supine to 1.2 (0.8-1.8) nu when standing. CONCLUSIONS: This study observed postoperative autonomic cardiovascular dysregulation that may contribute to limited HRV responses during early postoperative mobilization. TRIAL REGISTRATION: ClinicalTrials.gov NCT01089946.

Role of preoperative anemia for risk of transfusion and postoperative morbidity in fast-track hip and knee arthroplasty.

BACKGROUND: Preoperative anemia has been associated with increased risk of allogeneic blood transfusion and postoperative morbidity and mortality. The prevalence of preoperative anemia and its association with postoperative outcomes has not previously been reported in relation to fast-track elective total hip arthroplasty (THA) and total knee arthroplasty (TKA). We aimed to evaluate the prevalence of preoperative anemia in elective fast-track THA and TKA and its association with risk of perioperative transfusion, prolonged length of hospital stay (LOS), and postoperative readmission. STUDY DESIGN AND METHODS: This was a prospective observational database study with data obtained from six high-volume Danish fast-track surgical centers. Preoperative hemoglobin and patient demographics were collected prospectively using questionnaires while outcome and transfusion data were collected using national databases and patient charts. Adjusted risk estimates for transfusion, prolonged LOS, and all-cause readmission according to preoperative anemia status were obtained by multivariate logistic regression. RESULTS: A total of 5.165 THA or TKA procedures were included with a mean patient age of 67 ± 11 years and a median LOS of 2 (interquartile range, 2-3) days. A total of 662 patients (12.8%) had preoperative anemia according to World Health Organization classification. Preoperative anemia was associated with increased risk of receiving transfusion during admission (odds ratio [OR], 4.7; 95% confidence interval [CI], 3.8-5.8), increased risk of readmission within 90 days from surgery (OR, 1.4; 95% CI, 1.1-1.9), and increased risk of LOS of more than 5 days (OR, 2.5; 95% CI, 1.9-3.4) after adjustment for preoperative patient-related risk factors. CONCLUSION: Preoperative anemia in elective fast-track THA and TKA is independently associated with transfusion and increased postoperative morbidity, supporting the need for preoperative evaluation and treatment.

Does goal-directed fluid therapy affect postoperative orthostatic intolerance?: A randomized trial.

BACKGROUND: Early mobilization is important for postoperative recovery but is limited by orthostatic intolerance (OI) with a prevalence of 50% 6 h after major surgery. The pathophysiology of postoperative OI is assumed to include hypovolemia besides dysregulation of vasomotor tone. Stroke volume-guided fluid therapy, so-called goal-directed therapy (GDT), corrects functional hypovolemia, and the authors hypothesized that GDT reduces the prevalence of OI after major surgery and assessed this in a prospective, double-blinded trial. METHODS: Forty-two patients scheduled for open radical prostatectomy were randomized into standard fluid therapy (control group) or GDT groups. Both groups received a fixed-volume crystalloid regimen supplemented with 1:1 replacement of blood loss with colloid, and in addition, the GDT group received colloid to obtain a maximal stroke volume (esophageal Doppler). The primary outcome was the prevalence of OI assessed with a standardized mobilization protocol before and 6 h after surgery. Hemodynamic and hormonal orthostatic responses were evaluated. RESULTS: Twelve (57%) versus 15 (71%) patients in the control and GDT groups (P = 0.33), respectively, demonstrated OI after surgery, group difference 14% (CI, -18 to 45%). Patients in the GDT group received more colloid during surgery (1,758 vs. 1,057 ml; P = 0.001) and reached a higher stroke volume (102 vs. 89 ml; P = 0.04). OI patients had an increased length of hospital stay (3 vs. 2 days; P = 0.02) and impaired hemodynamic and norepinephrine responses on mobilization. CONCLUSION: GDT did not reduce the prevalence of OI, and patients with OI demonstrated impaired cardiovascular and hormonal responses to mobilization.

[Blood transfusion in major orthopaedic surgery]. / Blodtransfusion ved større ortopædkirurgiske operationer.

Hip and knee surgery is associated with a relatively large bleeding and a need for perioperative transfusion. Postoperative anaemia may delay recovery, but transfusion carries inherent risks. However, only few randomised controlled studies evaluating the effects of different transfusion triggers have been performed in orthopaedic surgery. The majority of these studies suffer from methodological weaknesses and have not been performed in a fast-track setting. Thus, large randomised studies evaluating a restrictive versus a liberal transfusion strategy in a procedure-specific setup are needed.

Middle cerebral artery flow velocity and pulse pressure during dynamic exercise in humans.

Exercise challenges cerebral autoregulation (CA) by a large increase in pulse pressure (PP) that may make systolic pressure exceed what is normally considered the upper range of CA. This study examined the relationship between systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP) and systolic (V(s)), diastolic (V(d)). and mean (V(m)) middle cerebral artery (MCA) blood flow velocity during mild, moderate, and heavy cycling exercise. Dynamic CA and steady-state changes in MCA V in relation to changes in arterial pressure were evaluated using transfer function analysis. PP increased by 37% and 57% during moderate and heavy exercise, respectively (P < 0.05), and the pulsatility of MCA V increased markedly. Thus exercise increased MCA V(m) and V(s) (P < 0.05) but tended to decrease MCA V(d) (P = 0.06). However, the normalized low-frequency transfer function gain between MAP and MCA V(m) and between SBP and MCA V(s) remained unchanged from rest to exercise, whereas that between DBP and MCA V(d) increased from rest to heavy exercise (P < 0.05). These findings suggest that during exercise, CA is challenged by a rapid decrease rather than by a rapid increase in blood pressure. However, dynamic CA remains able to modulate blood flow around the exercise-induced increase in MCA V(m), even during high-intensity exercise.