Introduction
The attempt to minimize exposure to allogeneic blood products remains a goal of perioperative care despite improvements in the safety of the blood supply. The risks of viral infection, bacterial contamination, hemolytic reactions, and transfusion-associated lung injury (TRALI) have been reviewed elsewhere. Evidence suggests that allogeneic blood transfusion may have immunosuppressive effects, possibly leading to increased cancer recurrence, increased susceptibility to wound infections, and even an increased mortality rate. Thus perioperative transfusion of blood products may be associated with an increase in perioperative morbidity and mortality rates.
Although many strategies decrease intraoperative blood loss, the use of regional anesthetic techniques has been suggested to diminish intraoperative blood loss and blood transfusions. In addition to decreasing perioperative morbidity and mortality rates, neuraxial blockade has been shown to diminish the risk of postoperative deep venous thrombosis and pulmonary embolism.
Options and Therapies
Many strategies have been suggested to decrease perioperative exposure to allogeneic blood products. These can generally be divided into three categories: (1) pharmaceuticals (e.g., erythropoietin, epsilon-aminocaproic acid, aprotonin, and blood substitutes); (2) techniques (e.g., minimally invasive and other surgical techniques, autologous donation, short-term normovolemic hemodilution, and deliberate hypotension); and (3) devices (e.g., intraoperative blood salvage). Many of these are discussed elsewhere. However, in comparison with these options, neuraxial regional techniques (e.g., spinal and epidural anesthesia) offer a particularly attractive alternative for reduction of perioperative hemorrhage because they are inherent to the anesthetic itself; they require no modification of surgical technique or additional pharmacologic manipulation. The majority of randomized data supports the use of neuraxial regional anesthetic techniques in decreasing blood loss and the need for blood transfusion; however, there is a lack of large-scale randomized data examining the effect of peripheral regional anesthesia on perioperative blood loss. Recently, three meta-analyses have been published evaluating the effects of neuraxial techniques on surgical blood loss and blood transfusion requirements. Data from at least two of these studies confirm the benefits of neuraxial anesthesia in reducing blood loss, although the combination of general anesthesia with epidural analgesia seems to negate the benefits of decreased blood loss.
Evidence
Since 1966, at least 139 studies comparing regional with general anesthesia have included either perioperative blood loss or transfusion requirement as an outcome measure. Of the two meta-analyses published in 2006, one identified 66 randomized controlled trials that compared neuraxial anesthesia with general anesthesia with a quantification of intraoperative blood loss and the other identified 24 trials. The large difference in trials included by the two meta-analyses may be explained by a much broader search (667 articles reviewed for inclusion versus 103 articles ) or possibly by unpublished exclusion or inclusion criteria that differed between the two studies. A 2009 meta-analysis of 28 randomized controlled trials comparing general anesthesia with regional anesthesia or analgesia for patients undergoing total knee arthroplasty found no difference in intraoperative blood loss but did note an improvement in the outcomes of postoperative pain and opioid-related adverse effects, a reduced hospital stay, and improved rehabilitation in the regional anesthesia and analgesia groups. A PubMed search through March 16, 2012, using the search criteria used by Richman and colleagues, identified 11 additional studies that would meet inclusion criteria if the analysis were repeated ( Table 53-1 ). A comparison of blood loss by location of surgery from the meta-analysis by Richman and colleagues is shown in Table 53-2, and a comparison of blood loss from trials limited to direct comparisons of various techniques is shown in Table 53-3 .
Author (Year) | Surgery | N = Total Subsets | EBL * | Transfusion † ‡ | Comments |
---|---|---|---|---|---|
Attari (2011) | Spine | N = 72 | |||
Lumbar disk | SA = 35 GA = 37 | 210 ± 40 350 ± 35 | Not reported | RCT SA versus GA for lumbar disk surgery comparing intraoperative and postoperative outcomes. Reported decreased EBL, improved hemodynamics. | |
Heidari (2011) | Ortho | N = 387 | |||
Elective hip fracture repair | NA = 190 GA = 197 | 458 ± 335 697 ± 424 | Not reported | RCT GA versus NA (either SA or GA) for elective hip fracture surgery. Outcomes followed EBL and Hb for 5 days. Concluded decreased EBL, postoperative pain, and hospital stay. | |
Tikuisis (2009) | Urology | N = 54 | |||
RRP | EA+GA = 27 GA = 27 | 740 ± 210 1150 ± 290 | 0.19 units 0.52 units | RCT GA+EA versus GA for RRP surgery. Outcome EBL and transfusion. Reported induced HoTN with EA/GA; decreased EBL and transfusion. | |
Sadrolsadat (2009) | Spine | N = 100 | |||
Lumbar disk | SA = 50 GA = 50 | 464 ± 69 438 ± 66 p = 0.054 | No transfusions | RCT SA versus GA in lumbar disk surgery. EBL was not a statically significant difference in either group. No transfusions were required. | |
O’Connor (2006) | Urology | N = 102 | |||
RRP | EA+GA = 51 GA = 51 | 955 ± 517 1477 ± 823 | 4% ‡ 3 units 18% ‡ 24 units | RCT EA+GA with deliberate HoTN versus GA. Primary outcome: percent age of patients transfused with allogeneic blood. Reported EA+GA had less EBL; less transfusion than GA group. | |
Eroglu (2005) | Ortho | N = 57 | |||
THA | EA = 20 GA = 37 | 305 (210-550 mL) 515 mL (380-780 mL) | 1.15 units 2.45 units | RCT HoTN EA versus HoTN GA (TIVA) in THA. Primary outcomes were EBL, Hb concentration, and transfusion in both groups. Reported HoTN in both groups and less EBL in EA versus GA group. | |
Yoshimoto (2005) | Spine | N = 40 | |||
Lumbar spine fusion | EA = 20 GA = 20 | 546 g 631 g | Not reported | RCT EA versus GA; primary outcome EBL, intraoperative HoTN, and postoperative analgesia. Reported less EBL in EA group. | |
Borghi (2005) | Ortho | N = 210 | |||
THA | EA = 70 EA+GA = 70 GA = 70 | 435 ± 233 449 ± 207 515 ± 219 * p not reported | No transfusions | RCT EA+GA versus EA. Primary outcome intraoperative and postoperative blood loss. The EA+GA group had lowest EBL compared with all groups. | |
Ozyuvaci (2005) | Urology | N = 50 | |||
Radical cystectomy | EA+GA = 25 GA = 25 | 875 ± 191 1248 ± 343 | 230 ±107 mL 420 ± 145 mL | RCT EA+GA versus GA. Primary outcomes EBL, transfusion MAP, and PCA use. EA+GA was lower in all outcomes. | |
Salonia (2004) | Urology | N = 72 | |||
RRP | SA = 38 GA = 34 | 984 ± 91 1247 ± 96 | 398 ± 49 mL 318 ± 53 mL | RCT SA versus GA in RRP surgery. Reported decreased EBL, postoperative pain, and faster recovery in SA versus GA group. | |
Hong (2003) | OB | N = 25 | |||
Cesarean section | EA = 13 GA = 12 | 1418 ± 996 1622 ± 775 not statistically significant | 0.38 ± 0.9 units 1.08 ± 1.6 units | RCT EA versus GA in elective C-section for placenta previa. Primary outcomes: maternal hemodynamics, EBL, transfusion, neonatal outcome. EBL was not statistically significant between the two groups. |
* All data are expressed in milliliters.
† All data are expressed as blood units unless noted as milliliters.
‡ Data are expressed as percentage of patients receiving transfusions. p values are less than 0.05 unless reported.
Surgery | Anesthesia | Mean Difference * | 95% CI | p Value |
---|---|---|---|---|
Abdominal | Spinal versus | |||
Epidural | –440 | –698/–181 | <0.001 | |
GA | –962 | –1169/–756 | <0.001 | |
EA–GA | –1344 | –1561/–1128 | <0.001 | |
Epidural versus | ||||
GA | –523 | –721/–324 | <0.001 | |
EA–GA | –905 | –1113/–696 | <0.001 | |
General versus | ||||
EA–GA | –382 | –521/–243 | <0.001 | |
Pelvic | Spinal versus | |||
Epidural | –315 | –375/–255 | <0.001 | |
GA | –235 | –280/–191 | <0.001 | |
EA–GA | –150 | –227/–72 | <0.001 | |
Epidural versus | ||||
GA | 79 | 23/135 | 0.001 | |
EA–GA | 165 | 81/249 | <0.001 | |
General versus | ||||
EA–GA | 85 | 12/160 | 0.011 | |
Lower Extremity | Spinal versus | |||
Epidural | –1 | –62/61 | 1.0 | |
GA | –65 | –111/–20 | 0.001 | |
EA–GA | –114 | –194/–34 | 0.001 | |
Epidural versus | ||||
GA | –65 | –120/–9 | 0.014 | |
EA–GA | –114 | –200/–27 | 0.003 | |
General versus | ||||
EA–GA | –49 | –125/27 | 0.529 |