Perioperative management of adults with sickle cell disease or thalassemia

INTRODUCTION — Patients with hemoglobinopathies have unique risks for complications during or after surgical procedures, especially cardiac surgery with cardiopulmonary bypass. Management encompasses the perioperative period. In addition, patients with sickle cell disease may require complex postoperative strategies for pain control due to chronic opioid use and opioid tolerance.

This topic discusses perioperative management of adults with common hemoglobinopathies such as sickle cell disease, sickle cell trait, or thalassemia.

Separate topics discuss general aspects of management:

●Sickle cell disease – (See "Overview of the management and prognosis of sickle cell disease" and "Red blood cell transfusion in sickle cell disease: Indications and transfusion techniques" and "Transfusion in sickle cell disease: Management of complications including iron overload".)

●Sickle cell trait – (See "Sickle cell trait".)

●Thalassemia – (See "Management of thalassemia".)

●Other hemoglobinopathies – (See "Hemoglobin variants including Hb C, Hb D, and Hb E".)

SICKLE CELL DISEASE — Sickle cell disease (SCD) includes all hemoglobinopathies with the sickle cell variant on one beta globin allele and another beta globin variant on the other allele.

●Sickle cell anemia (homozygous hemoglobin SS, Hb SS)

●Sickle cell-beta thalassemia

●Hemoglobin SC disease

●Other combinations with hemoglobin S, such as Hb D or Hb E

Hospitals that have a dedicated SCD program will ensure routine hematology involvement in perioperative planning. However, only a very small percentage of hospitals have such programs.

Preoperative assessment and optimization — If SCD is identified before elective major surgery, management of perioperative care should be in a center with a multidisciplinary team that includes hematology, anesthesiology, and surgery team members. For cardiac surgical procedures requiring cardiopulmonary bypass (CPB), perfusion team members should also participate. Considerations include disease severity, medications, baseline hemoglobin, percent abnormal hemoglobin (Hb S or other variant[s]), transfusion history, prior surgical complications, and the planned procedure.

●Review of history – In all cases, a thorough preoperative review of the patient’s clinical history and manifestations of SCD is necessary to determine perioperative risk factors (see "Overview of the clinical manifestations of sickle cell disease"). Manifestations of SCD that may require specialized preoperative optimization and intraoperative management are discussed in separate topics:

•Cardiomyopathy with diastolic dysfunction – (See "Perioperative management of heart failure in patients undergoing noncardiac surgery" and "Intraoperative management for noncardiac surgery in patients with heart failure".)

•Pulmonary hypertension – (See "Anesthesia for noncardiac surgery in patients with pulmonary hypertension or right heart failure".)

•Prior myocardial infarction or stroke – (See "Evaluation of cardiac risk prior to noncardiac surgery" and "Anesthesia for noncardiac surgery in patients with ischemic heart disease".)

•Asthma or other chronic lung disease – (See "Overview of the pulmonary complications of sickle cell disease" and "Anesthesia for adult patients with asthma".)

•Kidney dysfunction – (See "Sickle cell disease effects on the kidney", section on 'Prevention and management (sickle nephropathy)'.)

•Liver disease – (See "Anesthesia for the patient with liver disease".)

•Recent acute chest syndrome, defined as a new radiodensity on chest imaging with fever and/or respiratory symptoms in a patient with SCD. Non-emergency surgery is deferred until full recovery – (See "Acute chest syndrome (ACS) in sickle cell disease (adults and children)".)

•Prior venous thromboembolism with ongoing anticoagulation. (See "Perioperative management of patients receiving anticoagulants".)

●Hydration status – Individuals with SCD are at increased risk of volume depletion while not taking in oral fluids perioperatively, as they usually develop urinary concentrating defects as young children. For this reason, we continue oral clear liquids until two hours before surgery, as noted in standard fasting guidelines (table 1) (see "Preoperative fasting in adults"). For patients who are receiving "nothing per os" (NPO) for longer periods, we implement hydration with intravenous fluids (typically 5% dextrose with 0.45% NaCl) unless the case is scheduled as first in the morning. (See "Sickle cell disease effects on the kidney", section on 'Prevention and management (sickle nephropathy)' and "Overview of the management and prognosis of sickle cell disease", section on 'Management during hospitalization'.)

Decisions regarding prophylactic preoperative transfusion

Decision to transfuse — Individuals with SCD have a high frequency of serious perioperative complications, some of which may be ameliorated by preoperative red blood cell (RBC) transfusion. The risk versus benefit of no transfusions, conservative transfusions, or aggressive transfusions is unclear for many surgical procedures.

We agree with recommendations by the 2020 American Society of Hematology (ASH) guidelines on transfusion in SCD, which suggest preoperative transfusion for most patients with SCD undergoing elective surgical procedures requiring general anesthesia and lasting ≥1 hour [1].

Some individuals may avoid transfusion, such as those with a milder SCD phenotype (eg, Hb SC disease or sickle-beta⁺ thalassemia), those with higher baseline Hb F levels (>20 percent of total hemoglobin) due to hydroxyurea or hereditary persistence of fetal hemoglobin (HPFH), or those undergoing minor surgical procedures. For these individuals, decisions regarding preoperative simple transfusion depend on the individual's disease severity. (See "Hydroxyurea use in sickle cell disease", section on 'Monitoring and dose titration' and "Overview of compound sickle cell syndromes", section on 'Sickle-hereditary persistence of fetal hemoglobin'.)

Support for the use of perioperative transfusion in most patients with SCD comes from the Transfusion Alternatives Preoperatively in Sickle Cell Disease (TAPS) trial, which randomly assigned 70 children and adults with sickle cell anemia (Hb SS or sickle-beta⁰ thalassemia) to no preoperative transfusion or preoperative transfusion with a target hemoglobin level of 10 g/dL [2]. Patients were excluded if they had a hemoglobin concentration <6.5 g/dL, transfusion during the preceding three months, acute chest syndrome within the previous six months, oxygen saturation <90 percent, current dialysis, or a history of stroke in children. The median hemoglobin at entry was 7.7 to 8.0 g/dL, and most patients underwent intermediate-risk surgery. Due to an increased incidence of serious adverse events in the no-transfusion arm, this study was terminated early. Compared with no transfusion, those who received preoperative transfusion had the following benefits [2]:

●Fewer serious adverse events such as acute chest syndrome or acute pain episodes (3 versus 30 percent)

●More total units transfused (2.1 versus 1.2 units)

●Similar length of hospital stay

●Lower overall cost of resources

●Alloimmunization in one patient (versus none in the group that was not transfused)

This study excluded patients undergoing high-risk surgery such as cardiovascular or intracranial surgery. However, patients undergoing high-risk surgery may receive an additional benefit from prophylactic transfusion and/or a Hb S concentration of <30 percent.

Preoperative transfusion may not be necessary in patients undergoing brief minor procedures such as myringotomy, cataract extraction, skin biopsies, or other interventions requiring sedation or imaging procedures that require anesthesia. However, some individuals undergoing brief minor procedures may benefit from transfusion, especially if they have a history of surgical complications related to SCD.

Regardless of whether simple transfusion or exchange transfusion is used (see 'Transfusion approach (simple versus exchange)' below), extended crossmatching (ABO; Rh C, D and E; and Kell K antigens) is important in individuals with SCD due to their high risk of alloimmunization. RBC units should also be negative for sickle cell trait. (See "Red blood cell transfusion in sickle cell disease: Indications and transfusion techniques", section on 'Transfusion techniques' and "Transfusion in sickle cell disease: Management of complications including iron overload", section on 'Alloimmunization and hemolysis'.)

Risks of alloimmunization and other transfusion risks are discussed separately [3]. (See "Transfusion in sickle cell disease: Management of complications including iron overload", section on 'Likelihood of alloimmunization' and "Indications and hemoglobin thresholds for RBC transfusion in adults", section on 'Risks and complications of transfusion'.)

Transfusion approach (simple versus exchange)

●Patient-related considerations – For patients with SCD (homozygous Hb SS or Hb S-beta⁰ thalassemia) who have a baseline hemoglobin <9 g/dL and are undergoing cardiac or noncardiac surgery lasting ≥1 hour, we recommend preoperative simple transfusion. The goal is to raise the total hemoglobin to approximately 10 g/dL.

In an observational study of patients with lower-risk genotypes such as Hb SC disease or Hb S-beta⁺ thalassemia, the incidence of SCD-related complications in the subset of patients undergoing intra-abdominal procedures was significantly higher in patients not transfused prior to their surgery compared with those who were transfused (35 versus 0 percent) [4]. However, available evidence regarding perioperative outcomes is limited for these lower-risk genotypes. Patients who are relatively asymptomatic do not necessarily require preoperative transfusion therapy, with the exception of those undergoing cardiac surgery with CPB. (See 'Additional considerations for cardiac surgery with CPB' below.)

●Procedure-related considerations – For most patients with Hb SS or Hb S-beta⁰ thalassemia who are scheduled to undergo noncardiac surgery lasting ≥1 hour, we suggest simple rather than exchange transfusion. A conservative simple transfusion approach provides equivalent outcomes, similar rates of major complications, and fewer transfusion-related complications relative to exchange transfusion. These findings have been demonstrated in several multicenter cooperative studies performed by the National Preoperative Transfusion in Sickle Cell Disease Study Group [2,5-8].

Supporting evidence for simple transfusion — In a randomized study, 604 patients undergoing various types of surgical procedures were assigned to receive either an aggressive exchange transfusion regimen designed to reduce the Hb S to <30 percent, or a conservative transfusion regimen designed only to increase the Hb concentration to 10 g/dL [5]. The incidence of serious complications (31 and 35 percent) and acute chest syndrome (10 percent) were not different in the two groups. However, the aggressive transfusion group had a higher rate of transfusion-related complications such as alloimmunization (14 versus 7 percent) [5].

Limited data from patients undergoing specific types of surgical procedures include:

●Orthopedic surgery – Serious surgical complications such as excessive intraoperative blood loss (defined as loss of more than 10 percent of blood volume) occurred in 67 percent of these patients, while 17 percent had SCD-related complications (acute chest syndrome and vaso-occlusive events) [6].

●Cholecystectomy – SCD-related complications occurred in 19 percent of these patients undergoing cholecystectomy, and those who were not transfused had a higher incidence of such complications (32 percent). However, 10 percent of the patients in this study had transfusion-related complications [8].

●Ear, nose, and throat surgery – Serious complications including SCD-related complications or transfusion-related complications occurred in 32 percent of patients undergoing tonsillectomy and adenoidectomy, and in 36 percent of those undergoing myringotomy [7].

Exchange transfusion — For selected patients with moderate-to-high risk of vaso-occlusive complications, we suggest partial or full RBC exchange before surgery rather than simple transfusion. Only exchange transfusion is able to reduce the percent Hb S to <30 percent of total hemoglobin without raising the total hemoglobin above 11 g/dL (hemoglobin >11 g/dL is problematic since it increases the risk for hyperviscosity syndrome) [9-14]. Decisions to use exchange transfusion depend on:

●Patient-related considerations

•History of stroke, acute chest syndrome, multi-organ failure, or frequent vaso-occlusive pain episodes in the prior year, particularly if Hb S is >30 percent

•Prior surgical complications related to SCD

●Procedure-related considerations – High risk surgical procedures include:

•Surgery with CPB – An option for these cases is to perform the RBC exchange in the operating room after cannulation for bypass (see 'Additional considerations for cardiac surgery with CPB' below).

•Central nervous system surgery

•Organ transplant

•Major orthopedic surgery (eg, joint replacement for avascular necrosis)

•Need for emergency surgery during an acute SCD complication such as stroke or acute chest syndrome

●Patients with baseline hemoglobin ≥9 g/dL – Baseline hemoglobin ≥9 g/dL is too high to receive simple transfusion due to concerns about hyperviscosity

Exchange transfusion (RBC apheresis and replacement with large volumes of donor RBCs) is used to lower the percentage of hemoglobin that is Hb S and/or other variant hemoglobins without substantially raising the total hemoglobin; it can also be used to raise the total hemoglobin if needed. (See "Red blood cell transfusion in sickle cell disease: Indications and transfusion techniques", section on 'Exchange blood transfusion'.)

If automated RBC apheresis is not available, manual exchange or partial exchange may be used. As an example, 10 mL/kg of blood can be phlebotomized and an equivalent amount of allogeneic RBCs administered (typically, approximately 5 mL/kg of packed RBCs, which have a higher hemoglobin/hematocrit than whole blood). The percent Hb S may not be reduced below 30 percent by partial exchange transfusion. As an example, when partial exchange is used in individuals with Hb SC disease, Hb A >50 percent or Hb S plus Hb C <50 percent are reasonable targets [4].

Intraoperative management: General considerations — Hypovolemia, hypotension, acidosis, hypoxia, hypothermia, vasoconstriction, or the stress response to anesthesia and surgery may lead to sickling with risk of vaso-occlusive episodes [3]. Prolonged or exaggerated deoxygenation of hemoglobin can lead to hemoglobin precipitation with sickling of red cells. Intraoperative strategies to prevent or minimize sickling include:

●Maintain adequate hydration – Avoiding hypovolemia is critically important in patients with SCD. However, in those with underlying cardiomyopathy or kidney dysfunction, care is also taken to avoid overhydration. Invasive monitoring may be warranted to assist with decisions regarding fluid management. (See "Overview of the management and prognosis of sickle cell disease", section on 'Hydration' and "Intraoperative fluid management", section on 'Hypovolemia' and "Intraoperative fluid management", section on 'Hypervolemia'.)

Although data are limited, there is a concern that normal saline (NS) may prolong RBC transit times through the capillary system due to increased RBC stiffness [3]. Most centers use hypotonic solutions such as half-NS with dextrose for intravenous maintenance fluid therapy, while using balanced electrolyte solutions for fluid boluses to treat hypovolemia (eg, lactated Ringer’s solution or Plasmalyte) [3,15,16]. (See "Intraoperative fluid management", section on 'Crystalloid solutions'.)

●Maintain normothermia – Hypothermia can lead to vasoconstriction with increased risk of sickling. Causes, prevention, and management of hypothermia in the perioperative setting are discussed in detail in a separate topic. In situations where deliberate intraoperative hypothermia is planned (eg, hypothermic CPB), reducing the percentage of Hb S is considered in the preoperative period or before initiation of CPB. (See 'Decisions regarding prophylactic preoperative transfusion' above and 'Additional considerations for cardiac surgery with CPB' below.)

●Maintain adequate mean arterial pressure (MAP) – Maintain MAP within the patient's baseline preoperative range.

●Avoid use of a tourniquet – Avoid using a tourniquet in all patients.

●Avoid hypoxia – Maintain peripheral oxygen saturation (SpO₂) ≥95 percent to minimize risk of venous deoxygenation.

●Avoid acidosis – Maintain normal pH (ie, 7.40 to 7.45).

●Avoid use of a intraoperative blood salvage with a cell saver machine – Since the washing process in a cell saver machine may induce hemolysis or sickling of RBCs that contain Hb S, this blood salvage technique is avoided in most patients with SCD [3,10,17-20]. (See "Surgical blood conservation: Intraoperative blood salvage".)

Additional considerations for cardiac surgery with CPB

●Management before CPB – Specific strategies that may be employed before CPB for patients with SCD include:

•Exchange transfusion in the operating room – If circulating Hb S is >30 percent of total hemoglobin, pre-bypass rapid exchange transfusion is performed in the operating room by the perfusionist as CPB is being initiated [14]. This facilitates efficiency of the rapid exchange transfusion process, whether surgery is urgent or routine. This is accomplished by removing a portion of the patient's whole blood (which is discarded), while supplementing blood volume with a mixture of packed RBCs, fresh frozen plasma, albumin, and/or a balanced electrolyte crystalloid solution.

•Other potential modifications

-Use of an autotransfusion device – Before CPB, an autotransfusion device may be used to separate autologous plasma before CPB [21]. The plasma and clotting factors from the discarded blood can be sequestered using intraoperative plasmapheresis for later reinfusion.

-Use of a modified circuit to collect discarded blood – The perfusionist can modify the CPB circuit to allow a portion of the patient's blood to be collected and discarded during initiation of CPB. Combined with simultaneous infusion of donor blood, this technique will reduce circulating Hb S levels [22].

●Management during CPB – During CPB, control of temperature, oxygenation, and cardiac output (ie, pump flow rate) is managed by the perfusionist. Strategies to maximize tissue oxygen delivery and minimize sickling during CPB include:

•Use a centrifugal CPB pump, rather than a roller pump, to decrease damage to RBCs and risk of hemolysis [23].

•Maintain a cardiac index that is modestly higher than normal (ie, ≥2.4 L/minute/m²) by adjusting pump flow rates (see "Management of cardiopulmonary bypass", section on 'Protocols and standards'). If necessary, vasodilators may be administered to avoid hypertension due to the increased flow rate (table 2). However, sodium nitroprusside is avoided due to concern that excessive free hemoglobin may be present in patients with SCD and this may lead to the release of cyanide from the nitroprusside molecule [24].

•Maintain MAP at the higher end of the usual target range of 50 to 80 mmHg (see "Management of cardiopulmonary bypass", section on 'Mean arterial pressure targets'). Ideally, this is accomplished without high doses of vasopressor support.

•Maintain a higher-than-normal arterial oxygen tension (PaO₂) as necessary to target a higher mixed venous oxygen saturation (SvO₂ >80 percent), with monitoring of continuous arterial and venous blood gases.

•Avoid excessive unintentional hemoconcentration (eg, due to insensible losses) and avoid intentional hemoconcentration with use of hemofiltration.

•Administer sodium bicarbonate if necessary to treat acidosis and maintain pH 7.40 to 7.45.

•Avoid cold blood cardioplegia which may cause sickling and vaso-occlusion in the coronary arteries [10,25]. Instead, use cold crystalloid cardioplegia either exclusively, or initially before switching to warm blood cardioplegia.

•Minimize cooling during CPB except when necessary to perform certain procedures (eg, ascending aortic or arch reconstruction, pulmonary thromboendarterectomy). Lower systemic temperatures have been associated with sickling in vascular organ beds, increased hemolysis, and adverse outcomes in patients with SCD [26,27].

Postoperative considerations — Similar to the intraoperative period, efforts to avoid hypotension, acidosis, hypoxia, vasoconstriction, and venous stasis are continued during the immediate postoperative period. Particular emphasis is placed on the following considerations:

●Avoid or treat hypothermia – Ongoing warming in the post-anesthesia care unit (PACU) or intensive care unit (ICU) is often necessary to prevent hypothermia. (See "Perioperative temperature management", section on 'Hypothermia'.)

●Maintain oxygenation – Maintenance of oxygenation and immediate treatment of hypoxia remain critically important during the postoperative period. We maintain SpO₂ ≥95 percent, continuously monitor respiratory rate, and frequently reassess airway patency in extubated patients. After extubation, incentive spirometry and/or other interventions are used to reduce risks for atelectasis and acute chest syndrome for all patients with SCD. (See "Respiratory problems in the post-anesthesia care unit (PACU)".)

●Manage pain – Pain management is important to minimize distress that may lead to high catecholamine levels causing vasoconstriction or agitation with excessive oxygen consumption that can reduce SvO₂. Many adults with SCD are treated with chronic opioids for vaso-occlusive episodes. These patients develop high opioid tolerance and require higher doses of opioids for postoperative pain control. Fear of pain in the postoperative period may lead to splinting or atelectasis contributing to hypoxemia or acute chest syndrome. It is important to distinguish vaso-occlusive pain from acute pain due to the surgical incision or other complications such as pulmonary embolus. Consultation with the acute pain management team is typically necessary for patients with chronic pain and chronic use of opioids. (See "Use of opioids for postoperative pain control" and "Management of acute pain in the patient chronically using opioids for non-cancer pain".)

●Venous thromboembolism (VTE) prophylaxis – SCD is a hypercoagulable state that confers greatly increased risk of VTE compared with other patients without SCD [28,29]. (See "Overview of the clinical manifestations of sickle cell disease", section on 'Venous thromboembolism'.)

For this reason, postoperative VTE prophylaxis is particularly important. Details are discussed in separate topics:

•(See "Prevention of venous thromboembolic disease in adult nonorthopedic surgical patients".)

•(See "Prevention of venous thromboembolism in adults undergoing hip fracture repair or hip or knee replacement".)

•(See "Postoperative care after cardiac surgery", section on 'Venous thromboembolism prophylaxis'.)

SICKLE CELL TRAIT — Sickle cell trait (heterozygosity for the sickle cell variant) is generally considered to be a benign carrier condition. (See "Sickle cell trait".)

Many people with sickle cell trait are not aware that they carry the variant, either because they have not been tested or were not informed of test results. (See "Sickle cell trait", section on 'Newborn screening'.)

●Preoperative considerations – Preoperative screening for sickle cell trait is not uniformly done. It is likely that many individuals with sickle cell trait undergo surgery without having been informed of their sickle cell status.

●Considerations for CPB – Although sickle cell trait does not have an impact on major noncardiac surgical cases, case reports have described severe complications during cardiopulmonary bypass (CPB) [30]. However, it is not clear how commonly this occurs, as many individuals with sickle cell trait are unaware that they carry the sickle cell variant and routine screening is not performed. Institution-specific practices may allow testing before elective cardiac surgery with CPB if patients self-identify with a group at increased risk for carrying the sickle cell variant or who are determined to be at increased risk for any reason.

For patients who present with known sickle cell trait before elective cardiac surgery with CPB, a hematology consultation is obtained to determine if risks such as high baseline Hb S levels (>30 percent of total hemoglobin) should be managed. In one study of 170 individuals with sickle cell trait (unrelated to perioperative complications), 44 percent had Hb S >38 percent, 54 percent had Hb S between 31 and 38 percent, and 14 percent had Hb S <31 percent [31]. Although data are scant, for selected procedures such as cardiac surgery with hypothermic CPB, preoperative transfusion may be considered if Hb S is >30 percent [32]. (See 'Decisions regarding prophylactic preoperative transfusion' above and 'Additional considerations for cardiac surgery with CPB' above.)

●Postoperative considerations – Since risk of venous thromboembolism (VTE) is increased approximately 1.9-fold in patients with sickle cell trait compared with other patients, perioperative VTE prophylaxis warrants special attention. (See "Sickle cell trait", section on 'Venous thromboembolism'.)

THALASSEMIA — Thalassemia refers to a group of autosomal recessive genetic hemoglobinopathies in which globin chains are reduced, leading to hemolysis and anemia. Clinical severity depends on the imbalance between alpha and beta globin chains, which in turn depends on the number of globin genes affected. Patients with severe disease can develop increased iron stores, splenomegaly, and other manifestation of hemolysis and extramedullary hematopoiesis. (See "Diagnosis of thalassemia (adults and children)", section on 'Overview of subtypes and disease severity'.)

Common surgical procedures in individuals with thalassemia are splenectomy, cholecystectomy, liver biopsy, and cesarean birth.

Preoperative assessment and optimization

●Assessment for other systemic disease – A thorough preoperative review of the patient's history and complications related to thalassemia is important. (See "Management of thalassemia", section on 'Monitoring and management of disease complications' and "Iron chelators: Choice of agent, dosing, and adverse effects", section on 'Side effects'.)

The following issues are of particular concern for anesthetic care:

•Organ dysfunction – Clinical manifestations of thalassemia may include heart failure, arrhythmias, kidney or liver dysfunction due to iron overload, and use of certain iron chelation agents. Some individuals may have pulmonary hypertension or restrictive lung disease [33]. The preoperative evaluation may include additional testing depending on the patient's age, clinical condition, and findings on history and physical examination. Cardiovascular status is monitored closely during surgery. (See "Diagnosis of thalassemia (adults and children)", section on 'Heart failure and arrhythmias' and "Diagnosis of thalassemia (adults and children)", section on 'Pulmonary abnormalities and PH'.)

•Skeletal abnormalities – Deformities of the skull, facial bones, and spine that may accompany thalassemia may increase difficulty with airway management. Anesthesia providers should be prepared for this, especially in individuals with maxillary hyperplasia. Skeletal abnormalities may increase risk of fractures, as well, making regional anesthetic techniques (ie, neuraxial anesthesia and/or peripheral nerve blocks) difficult or impossible. (See "Diagnosis of thalassemia (adults and children)", section on 'Skeletal changes'.)

●Decisions regarding preoperative transfusion – Preoperative transfusion may be necessary in some cases [34,35].

Although no specific target hemoglobin has been identified, maintaining a level at the patient's normal baseline is reasonable before, during, and after surgery. Consideration of hemodilution during cardiopulmonary bypass (CPB) can be left to the anesthesia/perfusion team, as it is easy to supplement with allogeneic red blood cell (RBC) units while on CPB. (See 'Additional considerations for cardiac surgery with CPB' below.)

●Splenectomy – Patients undergoing splenectomy should receive immunizations including conjugate pneumococcal vaccination (15 or 20 valent), meningococcal vaccination (Men ACWY and Men B), and haemophilus influenza Type B vaccination (if not previously administered) in sufficient time to elicit an antibody response; this is critical to reduce the risk of post-splenectomy overwhelming infection. (See "Elective (diagnostic or therapeutic) splenectomy", section on 'Preoperative considerations'.)

Also, patients with a prior splenectomy have increased risk for perioperative infection and should have received appropriate vaccinations. (See "Prevention of infection in patients with impaired splenic function" and "Clinical features, evaluation, and management of fever in patients with impaired splenic function".)

Intraoperative management: General considerations

●Cardiovascular monitoring – In patients with significant cardiopulmonary disease, more intensive cardiovascular monitoring is prudent for major surgical procedures [33]. (See "Diagnosis of thalassemia (adults and children)", section on 'Heart failure and arrhythmias' and "Diagnosis of thalassemia (adults and children)", section on 'Pulmonary abnormalities and PH'.)

●Avoid intraoperative blood salvage using a cell saver device – We typically avoid use of a cell saver device because the washing process may induce hemolysis due to increased fragility of RBCs in patients with transfusion dependent thalassemia, particularly beta thalassemia [34]. (See "Surgical blood conservation: Intraoperative blood salvage".)

Additional considerations for cardiac surgery with CPB — Although data are scant regarding the possibility of increased risk for hemolysis during CPB in patients with thalassemia, the following strategies are prudent [36]:

●Use a centrifugal CPB pump rather than a roller pump – Damage to RBCs and risk of hemolysis are less likely with a centrifugal pump compared with a roller pump in patients with increased RBC fragility [23].

●Monitor closely for hemolysis – Hemolysis is suspected if pink-tinged urine indicating hemoglobinuria is observed. Also, we send plasma samples to obtain laboratory values for lactate dehydrogenase (LDH) and free hemoglobin levels, although results may be slow to return and comparison to baseline would be essential.

Postoperative considerations — Patients with thalassemia are at high risk for venous thromboembolism (VTE) [37]. (See "Management of thalassemia", section on 'Venous thromboembolism'.)

Patients undergoing splenectomy have a rapid increase in platelet count, with an increased risk of splenic vein thrombosis in the immediate postoperative period, so we recommend early initiation of VTE prophylaxis.

VTE prophylaxis is essential, particularly early initiation in patients with a previous splenectomy [38]. Information about VTE prophylaxis following surgery is provided separately:

●(See "Prevention of venous thromboembolic disease in adult nonorthopedic surgical patients".)

●(See "Prevention of venous thromboembolism in adults undergoing hip fracture repair or hip or knee replacement".)

●(See "Postoperative care after cardiac surgery", section on 'Venous thromboembolism prophylaxis'.)

Post-splenectomy considerations such as infection prophylaxis, vaccinations, and VTE prophylaxis are presented separately. (See "Elective (diagnostic or therapeutic) splenectomy", section on 'Postoperative risks'.)

SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Sickle cell disease and thalassemias".)

SUMMARY AND RECOMMENDATIONS

●Sickle cell disease (SCD)

•Preoperative – Consult a multidisciplinary team (hematology, anesthesiology, surgery) to consider procedural risks, disease severity, medications, baseline hemoglobin, percent sickle hemoglobin, transfusion history, and prior surgical and SCD complications, especially:

-Stroke

-Cardiomyopathy, pulmonary hypertension

-Myocardial infarction

-Acute chest syndrome, asthma, other chronic lung disease

-Kidney or liver dysfunction

-Multi-organ failure

-Pain history, opioid requirements (for adequate pain control)

(See 'Preoperative assessment and optimization' above.)

•Preoperative transfusion – Preoperative transfusion reduces surgical complications in selected individuals.

-For patients with Hb SS or sickle-beta⁰ thalassemia undergoing procedures lasting ≥1 hour, we suggest preoperative transfusion (Grade 2B). (See 'Decision to transfuse' above.)

-For most patients with hemoglobin <9 g/dL who are transfused, we suggest simple transfusion (Grade 2B). (See 'Transfusion approach (simple versus exchange)' above.)

-For selected high-risk settings, we suggest exchange transfusion (Grade 2C). Examples include high-risk patients (prior stroke or SCD-related surgical complications), procedures (cardiac surgery with cardiopulmonary bypass [CPB], organ transplant, major orthopedic surgery), and patients with baseline hemoglobin ≥9 g/dL (to avoid risks of hyperviscosity). (See 'Transfusion approach (simple versus exchange)' above.)

Extended red blood cell (RBC) matching helps avoid alloimmunization. Blood should be negative for sickle cell trait. (See "Red blood cell transfusion in sickle cell disease: Indications and transfusion techniques", section on 'RBC antigen matching'.)

•Intraoperative – Vaso-occlusion can be worsened by hypovolemia, hypotension, acidosis, hypoxia, hypothermia, vasoconstriction, stress response, or venous stasis (see 'Intraoperative management: General considerations' above):

Avoid cell saver (can induce hemolysis) and maintain:

-Hydration

-Normothermia

-Baseline mean arterial pressure (MAP)

-Peripheral oxygen saturation (SpO₂) ≥95 percent

-pH 7.40 to 7.45

•Cardiac surgery with CPB – Exchange transfusion can be done in the operating room using a discard cardiotomy reservoir. (See 'Additional considerations for cardiac surgery with CPB' above.)

In addition to the above, and provided hemolysis is not induced, management includes:

-We suggest a centrifugal CPB pump rather than a roller pump (Grade 2C).

-Maintain higher CPB flow (cardiac index ≥2.4 L/minute/m², versus 2.2 to 2.4 L/minute/m² in individuals without SCD).

-Maintain MAP >60 mmHg using greater than normal CPB flow rates rather than vasopressors.

-Maintain mixed venous oxygen saturation >80 percent.

-Avoid cold blood cardioplegia; use cold crystalloid cardioplegia exclusively or before switching to warm blood cardioplegia.

•Postoperative – Along with the above, ensure adequate:

-Pain management. (See "Use of opioids for postoperative pain control" and "Management of acute pain in the patient chronically using opioids for non-cancer pain".)

-Venous thromboembolism (VTE) prophylaxis. (See "Overview of the management and prognosis of sickle cell disease", section on 'Thromboembolism prophylaxis' and "Prevention of venous thromboembolic disease in adult nonorthopedic surgical patients" and "Prevention of venous thromboembolism in adults undergoing hip fracture repair or hip or knee replacement".)

-Incentive spirometry. (See "Strategies to reduce postoperative pulmonary complications in adults" and "Overview of the management and prognosis of sickle cell disease", section on 'Incentive spirometry'.)

●Sickle cell trait – Sickle cell trait does impact noncardiac surgical cases; preoperative screening is individualized. Since severe complications can occur during CPB, a hematology consultation is obtained. (See 'Sickle cell trait' above.)

●Thalassemia

•Preoperative – Evaluate for heart failure, pericarditis, arrhythmias, pulmonary hypertension, kidney or liver dysfunction (due to iron overload), and use of certain iron chelators. Preoperative transfusion may be necessary, although no specific target hemoglobin has been identified. Deformities of the skull, facial bones, and spine may increase difficulty with airway management and regional anesthesia. (See 'Preoperative assessment and optimization' above.)

•Surgery with CPB – Considerations to minimize and detect hemolysis include (see 'Additional considerations for cardiac surgery with CPB' above):

-We suggest a centrifugal CPB pump rather than a roller pump (Grade 2C). This decreases hemolysis risk.

-Close monitoring for hemolysis (eg, hemoglobinuria, lactate dehydrogenase, free hemoglobin levels).

•Postoperative – VTE prophylaxis is essential, particularly in splenectomized patients. (See "Management of thalassemia", section on 'Venous thromboembolism' and "Prevention of venous thromboembolic disease in adult nonorthopedic surgical patients" and "Prevention of venous thromboembolism in adults undergoing hip fracture repair or hip or knee replacement".)