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Impact of malnutrition on outcomes following groin hernia repair: Insights from the ACS NSQIP

Open AccessPublished:August 29, 2022DOI:https://doi.org/10.1016/j.surg.2022.07.022

      Abstract

      Background

      The present study examined the association of nutrition status, as defined by preoperative serum albumin, with postoperative outcomes and resource use after groin hernia repair.

      Methods

      The 2006 to 2019 American College of Surgeons National Surgical Quality Improvement Program database was queried for adults (≥18 years) undergoing open or laparoscopic repair of inguinal or femoral hernia. Patients were stratified based on the following preoperative serum albumin levels: <2.5 g/dL (severe hypoalbuminemia), 2.5 to <3.0 (moderate hypoalbuminemia), 3.0 to <3.5 (mild), and ≥3.5 (normal albumin). Multivariable regression models were developed to assess the association of hypoalbuminemia with outcomes of interest, including 30-day mortality, postoperative complications, length of stay, and 30-day readmission.

      Results

      Of the 261,052 patients meeting inclusion criteria, 0.3% had severe, 1.1% had moderate, and 7.4% had mild hypoalbuminemia, with 91.2% classified as normal albumin. After risk adjustment, mortality risk was greater for severe (5.8%, 95% confidence interval: 4.1–7.6), moderate (4.4%, 95% confidence interval: 3.4–5.3), and mild hypoalbuminemia (1.5%, 95% confidence interval: 1.2-1.8) relative to normal albumin (0.3%, 95% confidence interval: 0.2–0.3). Decreasing serum albumin levels were associated with a stepwise increase in risk of complications, length of stay, and 30-day readmission.

      Conclusion

      Decreased preoperative serum albumin is associated with increased mortality and morbidity after open and laparoscopic groin hernia repair. Serum albumin remains a relevant predictor of postsurgical outcomes and can thus be used in shared decision-making and optimization of malnourished patients in need of groin hernia repair.

      Introduction

      Groin hernia repairs account for a large proportion of the global surgical volume, with >20 million operations performed annually.
      • Kingsnorth A.
      • LeBlanc K.
      Inguinal and incisional hernias.
      Although these operations are common, complications such as surgical site and mesh infections occur in as many as 5% to 7% of cases, whereas 10% to 15% of patients require a reoperation.
      • Simons M.P.
      • Smietanski M.
      • Bonjer H.J.
      • et al.
      International guidelines for groin hernia management.
      Consequently, guidelines have been developed to standardize surgical approaches for repair and reduce rates of postoperative complications.
      • Simons M.P.
      • Smietanski M.
      • Bonjer H.J.
      • et al.
      International guidelines for groin hernia management.
      Although these recommendations provide input regarding surgical technique and activity restrictions, data regarding appropriate patient selection and optimization of risk factors remain inadequate.
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      Comments on the new groin hernia guidelines: what has changed? What has remained unanswered?.
      ,
      • Schmidt L.
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      Surgical techniques and convalescence recommendations vary greatly in laparoscopic groin hernia repair: a nationwide survey among experienced hernia surgeons.
      This uncertainty is further exacerbated by the adoption of laparoscopic or robotic approaches to hernia repair, which typically require general anesthesia, further altering the perioperative risk of these procedures.
      Over 2 decades ago, the National Veterans Administration Surgical Risk Study established preoperative serum albumin levels as a strong predictor of outcomes after major operations, including general, thoracic, and orthopedic.
      • Khuri S.F.
      • Daley J.
      • Henderson W.
      • et al.
      Risk adjustment of the postoperative mortality rate for the comparative assessment of the quality of surgical care: results of the National Veterans Affairs Surgical Risk Study.
      ,
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      • Henderson W.
      • Daley J.
      • Hur K.
      • Khuri S.F.
      Preoperative serum albumin level as a predictor of operative mortality and morbidity: results from the National VA Surgical Risk Study.
      Hypoalbuminemia, defined as serum albumin <3.5 g/dL,
      • Weaving G.
      • Batstone G.F.
      • Jones R.G.
      Age and sex variation in serum albumin concentration: an observational study.
      has been used as a marker for malnutrition and remains a powerful predictor of postoperative outcomes.
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      • Liu J.
      Hypoalbuminemia more than morbid obesity is an independent predictor of complications after total hip arthroplasty.
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      • Della Valle C.J.
      Hypoalbuminemia independently predicts surgical site infection, pneumonia, length of stay, and readmission after total joint arthroplasty.
      Specifically, prior work has demonstrated hypoalbuminemia to be associated with increased mortality, postoperative complications, and resource use, independent of body mass index (BMI) and other comorbidities.
      • Nisar P.J.
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      • Remzi F.H.
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      Preoperative hypoalbuminemia is associated with adverse outcomes after ileoanal pouch surgery.
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      Albumin and surgical site infection risk in orthopaedics: a meta-analysis.
      • Rudasill S.E.
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      • Sanaiha Y.
      • et al.
      Predicting morbidity and mortality in laparoscopic cholecystectomy: preoperative serum albumin still matters.
      However, contemporary large-scale studies examining the impact of hypoalbuminemia on outcomes of groin hernia repair are generally lacking. Given the high volume of groin hernia repairs performed annually, identifying predictive and clinically modifiable factors is highly relevant.
      The present national study characterized the association of hypoalbuminemia with clinical outcomes, length of stay, and readmissions after open and laparoscopic repair of groin hernia. We hypothesized that low serum albumin levels would be associated with higher rates of postoperative mortality, complications, and readmissions, as well as increased duration of hospitalization.

      Methods

      This was a retrospective study using the American College of Surgeons (ACS) National Surgical Quality Improvement Program (NSQIP) 2006 to 2019 participant use data files. Over 600 hospitals contribute to the NSQIP database to evaluate perioperative outcomes, as well as reporting 30-day morbidity and mortality. All adults (≥18 years) undergoing open or laparoscopic repair of groin (inguinal and femoral) hernias were identified using relevant Current Procedural Terminology primary procedure codes (Supplemental Table S1). Patients with missing data on age, sex, and clinical status of hernia, as well as concurrent or additional procedures, were excluded (Figure 1).
      Figure thumbnail gr1
      Figure 1Patient selection criteria. Of the 365,296 inguinal and femoral hernia repair patients identified, 261,052 (71.5%) met inclusion criteria.
      To account for missing serum albumin data, we performed univariate imputations using multinomial linear regression. Patients were then stratified based on the following preoperative levels of serum albumin: <2.5 g/dL (severe hypoalbuminemia), 2.5 to <3.0 g/dL (moderate hypoalbuminemia), 3.0 to <3.5 g/dL (mild hypoalbuminemia), and ≥3.5 g/dL (normal albumin). The patient characteristics of interest included age, sex, race, functional status, comorbidities, American Society of Anesthesiologists class, and BMI. The perioperative characteristics included operative approach, case urgency, surgical setting, and preoperative serum laboratory values (Table I). The patient and perioperative characteristics were defined according to the NSQIP data dictionary.

      American College of Surgeons National Surgical Quality Improvement Program. User guide for the 2016 ACS NSQIP participant use data file (PUF); 2017 https://www.facs.org/∼/media/files/quality%20programs/nsqip/nsqip_puf_userguide_2016.ashx. Accessed August 12, 2021.

      Hernias were classified into uncomplicated, incarcerated, or strangulated using International Classification of Diseases, Tenth Revision codes for postoperative diagnoses (Supplemental Table S2).
      Table IBaseline patient and perioperative characteristics stratified by albumin class for patients undergoing groin hernia repair
      VariableAlbumin <2.5 (n = 688)Albumin 2.5 to <3.0 (n = 2,973)Albumin 3.0 to <3.5 (n = 19,364)Albumin ≥3.5 (n = 238,027)P value
      Age, median (IQR), y52 (42–64)55 (45–65)53 (43–63)46 (36–56)< .001
      Female patients, %16.014.613.310.5< .001
      Race, %< .001
       White69.272.372.472.8
       Black12.59.28.17.8
       Asian/PI2.82.83.03.0
       Other/unknown
      Unknown indicates no recorded data for race.
      15.515.816.516.4
      Functional status, %< .001
       Independent89.592.496.899.2
       Partially dependent9.56.32.70.7
       Totally dependent1.01.40.50.1
      Comorbidities, %
       Ascites11.84.41.00.1< .001
       CHF3.63.01.20.5< .001
       COPD11.69.26.23.4< .001
       Diabetes mellitus15.412.49.47.4< .001
       Dialysis use7.94.11.70.5< .001
       Hypertension58.655.550.540.7< .001
       Smoking history26.017.215.817.8< .001
      ASA class, %< .001
       11.05.28.813.9
       222.534.847.456.7
       355.147.738.527.4
       4+21.412.35.32.0
      BMI, mean ± SD, kg/m225.2 ± 5.725.8 ± 4.826.3 ± 4.826.9 ± 4.7< .001
      Hernia type, %< .001
       Uncomplicated64.774.584.189.0
       Incarcerated34.525.015.710.8
      Strangulated0.90.50.20.2
      Operative characteristics
       Operative time, median (IQR), min63 (47–87)59 (43–81)56 (41–78)57 (41–79)< .001
       Open approach, %87.281.975.970.1< .001
       Emergency, %15.410.95.73.3< .001
       Inpatient, %44.629.615.38.8< .001
      Preoperative serum values, mean ± SD
       Albumin, g/dL2.1 ± 0.32.8 ± 0.13.3 ± 0.14.2 ± 0.4< .001
       HCT, %34.9 ± 6.637.4 ± 6.140.2 ± 5.342.4 ± 4.4< .001
       Creatinine, mg/dL1.5 ± 1.71.4 ± 1.41.2 ± 1.01.1 ± 0.7< .001
       BUN, mg/dL21.6 ± 16.621.5 ± 15.219.8 ± 11.517.7 ± 8.2< .001
       Bilirubin, mg/dL1.2 ± 1.41.0 ± 1.10.8 ± 0.80.7 ± 0.5< .001
      ASA, American Society of Anesthesiologists; BMI, body mass index; BUN, blood urea nitrogen; CHF, congestive heart failure; COPD, chronic obstructive pulmonary disease; HCT, hematocrit; PI, Pacific Islander.
      Unknown indicates no recorded data for race.
      The primary outcome of interest was 30-day mortality, whereas the secondary outcomes included postoperative complications, length of stay (LOS), and 30-day readmission. Postoperative complications considered included bleeding, wound dehiscence, infectious (septic shock, superficial, deep, and organ surgical site infection), respiratory (pneumonia, reintubation, prolonged mechanical ventilation), deep venous thrombosis (DVT), acute renal failure, and reoperation.
      The categorical variables are reported as frequency (%), and the continuous variables are reported as mean with SD or median and IQR if non-normally distributed. The χ2 analysis and Kruskal-Wallis analysis of variance were used to compare patient demographics, comorbidities, and outcomes by albumin class. Multivariable logistic and Poisson regression models were developed to evaluate the association of albumin class with outcomes of interest. Variable selection was guided by the least absolute shrinkage and selection operator using the Stata xpologit and xpopoisson commands. Briefly, the least absolute shrinkage and selection operator is an automated algorithm that reduces model overfitting and improves out-of-sample reliability.
      • Tibshirani R.
      Regression shrinkage and selection via the lasso.
      We selected models to minimize the mean squared error term and evaluated them using the receiver-operating characteristics as well as Akaike and Bayesian information criteria, as appropriate. Final models (λ: 0.0093) included adjustment for demographics (age, sex, race, and functional status), operative characteristics (diagnosis, approach, emergency, and ASA class), comorbidities (ascites, congestive heart failure, chronic obstructive pulmonary disease, and dialysis use), and preoperative serum laboratory values (serum blood urea nitrogen, bilirubin, creatinine, and hematocrit). The continuous variables were entered as linear in the final models. The Stata margins command was used to generate adjusted predicted risks of the study end points. All statistical analyses were performed using STATA 16.0 (Stata Corporation, College Station, TX). The study was deemed exempt from full review by the Institutional Review Board at the University of California, Los Angeles.

      Results

      Of the 365,296 groin hernia patients identified, 261,052 (71.5%) met inclusion criteria (Figure 1). A total of 688 (0.3%) were in the severe hypoalbuminemia cohort, with another 2,973 (1.1%) classified as moderate hypoalbuminemia, 19,364 (7.4%) as mild hypoalbuminemia, and 238,027 (91.2%) as normal albumin.
      Compared to normal albumin, the severe hypoalbuminemia cohort was older (52 [42–64] vs 46 [36–56], P < .001), more commonly women (16.0% vs 10.5%, P < .001), and Black (12.5% vs 7.8%, P < .001, Table I). Patients with severe hypoalbuminemia had a higher prevalence of incarcerated (34.5% vs 10.8%, P < .001) and strangulated groin hernias (0.9% vs 0.2%, P < .001), faced longer operative times (63 [47–87] vs 57 [41–79] minutes, P < .001), and more frequently underwent emergency (15.4% vs 3.3%, P < .001), open (87.2% vs 70.1%, P < .001), or inpatient procedures (44.6% vs 8.8%, P < .001, Table I).
      Unadjusted postoperative outcomes by albumin class following groin hernia repair are shown in Table II. Compared to others, severe hypoalbuminemia patients had higher rates of mortality (4.9% vs 0.2%, P < .001), perioperative bleeding (2.6% vs 0.1%, P < .001), pneumonia (2.2% vs 0.2%, P < .001), and septic shock (1.5 vs 0.1%, P < .001). Furthermore, patients with severe hypoalbuminemia had greater rates of reintubation (2.3% vs 0.1%, P < .001), reoperation (2.8% vs 0.7%, P < .001), 30-day readmission (10.3% vs 1.8%, P < .001), and longer postoperative LOS (1 [0–3] vs 0 [0–0] days, P < .001).
      Table IIUnadjusted postoperative outcomes after groin hernia repair by albumin class
      VariableAlbumin <2.5 (n = 688)Albumin 2.5 to <3.0 (n = 2,973)Albumin 3.0 to <3.5 (n = 19,364)Albumin ≥3.5 (n = 238,027)P value
      Mortality, %4.92.40.60.2< .001
      Bleeding, %2.61.40.40.1< .001
      Dehiscence, %0.30.10.10.1.01
      Surgical site infection, %1.61.00.70.5< .001
      Pneumonia, %2.21.10.50.2< .001
      Septic shock, %1.50.70.20.1< .001
      Prolonged mechanical ventilation, %2.50.90.20.1< .001
      DVT, %0.90.20.20.1< .001
      Renal failure, %2.31.60.30.1< .001
      Reintubation, %2.31.00.30.1< .001
      Reoperation, %2.82.21.10.7< .001
      Postoperative LOS, d1 (0–3)1 (0–3)1 (0–1)0 (0–0)< .001
      30-day readmission, %10.36.73.41.8< .001
      DVT, deep venous thrombosis; LOS, length of stay.
      Multivariable regression was used to test the independent association of preoperative serum albumin with mortality using covariates shown in Table III. After an adjustment for intergroup differences, severe hypoalbuminemia was associated with significantly higher odds of 30-day mortality (adjusted odds ratio [AOR] 4.07, 95% CI: 2.59–6.40, ref: normal albumin). Other significant factors independently associated with increased odds of mortality included increasing age (AOR 1.05/y, 95% CI: 1.04–1.06), partial (AOR 2.49, 95% CI: 1.88–3.29), and totally dependent functional status (AOR 2.30, 95% CI: 1.26–4.21; ref: independent), emergency operations (AOR 1.96, 95% CI: 1.49–2.57), and inpatient hospital setting (AOR 3.52, 95% CI: 2.59–4.79), among others (Table III). The predicted risk for mortality was greater for severe (5.8%, 95% CI: 4.1–7.6), moderate (4.4%, 95% CI: 3.4–5.3), and mild hypoalbuminemia (1.5%, 95% CI: 1.2–1.8) relative to normal albumin (0.3%, 95% CI: 0.2–0.3). Worsening hypoalbuminemia was associated with a stepwise increase in risk-adjusted probability of mortality and complications for groin hernia repairs (Figure 2). Moreover, a greater distribution of patients experiencing 30-day mortality had hypoalbuminemia (Figure 3).
      Table IIILogistic regression on death and septic shock following groin hernia repair (C-statistic: 0.92)
      MortalityComplications
      Indicates a composite variable of complications, including perioperative bleeding, dehiscence, superficial SSI, deep SSI, organ SSI, pneumonia, septic shock, prolonged mechanical ventilation, DVT, renal failure, reintubation, reoperation, and 30-day readmission.
      AORP value95% CIAORP value95% CI
      Albumin class, g/dL
       ≥3.5RefRef
       3.0 to <3.51.59.0011.19–2.111.32< .0011.15–1.51
       2.5 to <3.02.81< .0012.00–3.961.34.0051.09–1.65
       ≤2.54.07< .0012.59–6.401.78< .0011.34–2.38
      Age, /y1.05< .0011.04–1.061.01< .0011.01–1.01
      Female patients0.75.040.57–0.981.01.810.90–1.14
      Race
       WhiteRefRef
       Black0.85.390.58–1.231.05.530.91–1.21
       Asian/PI0.79.500.39–1.581.00.970.76–1.30
       Other/unknown
      Unknown indicates no recorded data for race.
      0.75.120.52–1.080.95.440.82–1.09
      Function
       IndependentRefRef
       Partially dependent2.49< .0011.88–3.291.82< .0011.53–2.17
       Totally dependent2.30.0071.26–4.212.10.0011.34–3.02
      Ascites2.23.0021.35–3.692.12< .0011.62–2.78
      CHF1.97< .0011.40–2.781.44.0021.15–1.81
      COPD1.77< .0011.36–2.311.45< .0011.26–1.67
      Dialysis1.75.110.88–3.480.74.150.49–1.12
      ASA class
       1RefRef
       21.48.590.35–6.211.41.021.07–1.87
       33.55.080.86–14.62.28< .0011.72–3.03
       4+8.74.0032.10–36.433.06< .0012.24–4.19
      BMI0.97.0050.94–0.991.02< .0011.01–1.03
      Hernia clinical status
       UncomplicatedRefRef
       Incarcerated1.73< .0011.31–2.281.49< .0011.34–1.67
       Strangulated2.73.031.13–6.603.55< .0012.34–5.38
      Open approach0.86.370.61–1.200.97.610.86–1.09
      Emergency1.96< .0011.49–2.571.63< .0011.43–1.86
      Inpatient3.52< .0012.59–4.793.23< .0012.88–3.61
      Preoperative hematocrit, %1.00.900.98–1.020.97< .0010.96–0.98
      Preoperative Creatinine, mg/dL0.99.890.87–1.131.04.220.98–1.11
      Preoperative BUN, mg/dL1.02< .0011.01–1.021.01< .0011.01–1.01
      Preoperative bilirubin, mg/dL1.19.0041.05–1.331.05.130.98–1.12
      AOR, adjusted odds ratio; ASA, American Society of Anesthesiologists classification; BMI, body mass index; BUN, blood urea nitrogen; COPD; chronic obstructive pulmonary disease; DVT, deep vein thrombosis; CHF, congestive heart failure; PI, Pacific Islander; SSI, surgical site infection.
      Indicates a composite variable of complications, including perioperative bleeding, dehiscence, superficial SSI, deep SSI, organ SSI, pneumonia, septic shock, prolonged mechanical ventilation, DVT, renal failure, reintubation, reoperation, and 30-day readmission.
      Unknown indicates no recorded data for race.
      Figure thumbnail gr2
      Figure 2Association of preoperative serum albumin and risk-adjusted probability of mortality and complications following groin hernia repair.
      Figure thumbnail gr3
      Figure 3Probability distribution of preoperative serum albumin stratified by patients experiencing death within 30 days of groin hernia repair.
      We subsequently evaluated for association between preoperative serum albumin level and postoperative complications, LOS, and 30-day readmissions, as shown in Table IV. Severe hypoalbuminemia was independently associated with increased predicted probability of perioperative bleeding (3.3% vs 0.2%, P < .001), pneumonia (2.1% vs 0.3%, P < .001), septic shock (1.8% vs 0.1%, P < .001), prolonged mechanical ventilation (2.9% vs 0.1%, P < .001), DVT (1.1% vs 0.1%, P < .001), acute renal failure (2.6% vs 0.1%, P < .001), reintubation (2.6% vs 0.2%, P < .001), and reoperation (2.7% vs 1.0%, P < .001). Risk-adjusted hospital LOS was greater for patients with severe hypoalbuminemia (3.0 [2.9–3.2] vs 0.5 [0.5–0.5] days, P < .001). Furthermore, severe hypoalbuminemia was associated with a significantly higher predicted risk of 30-day readmission compared to normal albumin (11.6% vs 2.5%, P < .001, Table IV).
      Table IVRisk-adjusted probability of complications following groin hernia repair by albumin class
      VariableAlbumin <2.5 (n = 630)Albumin 2.5 to <3.0 (n = 1,517)Albumin 3.0 to <3.5 (n = 5,402)Albumin ≥3.5 (n = 253,503)P value
      Mortality, %5.84.41.50.3< .001
      Bleeding, %3.32.71.00.2< .001
      Dehiscence, %0.4
      Indicates no predicted probability of outcome due to insufficient number of cases.
      0.20.1< .001
      Surgical site infection, %1.81.41.30.5< .001
      Pneumonia, %2.22.11.30.3< .001
      Septic shock, %1.81.40.50.1< .001
      Prolonged mechanical ventilation, %2.92.00.60.1< .001
      DVT, %1.10.40.50.1< .001
      Renal failure, %2.62.70.70.1< .001
      Reintubation, %2.61.90.80.2< .001
      Reoperation, %2.73.32.21.0< .001
      Postoperative LOS, d3.0 (2.9–3.2)2.5 (2.4–2.6)1.5 (1.5–1.6)0.5 (0.5–0.5)< .001
      30-d readmission, %11.610.67.62.5< .001
      DVT, deep venous thrombosis; LOS, length of stay.
      Indicates no predicted probability of outcome due to insufficient number of cases.
      To assess the association between serum albumin levels and risk of mortality, we performed a sensitivity analysis examining mortality outcomes stratified by elective versus emergency operations as well as clinical status of hernia. Decreasing serum albumin was associated with a stepwise increase in predicted probability of death after elective operations and repair of uncomplicated groin hernias. The results are further detailed in Supplemental Table S3.

      Discussion

      Given the large annual volume of inguinal and femoral hernia repairs, identification of risk factors for postoperative events is paramount to patient safety and increasing value of care.
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      Although serum albumin has been previously established as a strong predictor of postsurgical outcomes, data regarding its impact on outcomes following groin hernia repair are currently lacking. The present study used a large national cohort to demonstrate the impact of hypoalbuminemia on mortality and complications following repair of inguinal and femoral hernias. We found preoperative serum albumin levels to be inversely related to the risk of death. Additionally, worsening hypoalbuminemia was significantly associated with an increased risk of developing septic shock, bleeding, pneumonia, prolonged mechanical ventilation, DVT, renal failure, as well as reintubation, reoperation, and 30-day readmission.
      Prior studies have linked malnutrition to inferior postoperative outcomes.
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      they can be tedious, subjective, and time-consuming. As such, efficient markers for malnutrition are necessary to optimize patient outcomes. Previous work has established albumin as a marker of malnutrition, which has been associated with tolerance of surgical stress.
      • Minasyan H.
      Sepsis and septic shock: pathogenesis and treatment perspectives.
      Poor albumin reserve in high-risk patients provides insight into their ability to biosynthesize proteins and factors necessary for homeostasis, healing, and immune response.
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      This may, in part, explain our observation that patients with worsening hypoalbuminemia faced an increased risk of septic shock and other complications. The ACS has championed the Strong for Surgery program,
      American College of Surgeons
      Standards and staging. Strong for surgery.
      which includes a screening checklist for malnutrition, including BMI, unintentional weight loss, poor appetite, and oral intake ability. Additionally, it recommends checking serum albumin levels for those undergoing inpatient procedures. Our study supported the relevance of this marker in predicting clinical outcomes after groin hernia repair. Thus, we recommend checking albumin levels in groin hernia patients deemed clinically appropriate for inpatient surgery as well as those that meet initial screening criteria for malnutrition.
      Although hypoalbuminemia is generally defined as albumin <3.5 g/dL, we observed a more granular and sustained relationship between serum levels and mortality. Specifically, albumin <2.5 g/dL was independently associated with a 20-fold increase in risk of mortality. This finding was consistent with the relationship between albumin and postoperative mortality demonstrated by the National Veterans Administration Surgical Risk Study.
      • Khuri S.F.
      • Daley J.
      • Henderson W.
      • et al.
      Risk adjustment of the postoperative mortality rate for the comparative assessment of the quality of surgical care: results of the National Veterans Affairs Surgical Risk Study.
      ,
      • Gibbs J.
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      • Henderson W.
      • Daley J.
      • Hur K.
      • Khuri S.F.
      Preoperative serum albumin level as a predictor of operative mortality and morbidity: results from the National VA Surgical Risk Study.
      Furthermore, we found that patients with severe hypoalbuminemia faced a 5.4-fold increase in developing complications relative to those with normal albumin levels. Patients in the moderate and mild hypoalbuminemia cohorts experienced a 4.7- and 3.0-fold increase in complication risk, respectively. This finding suggested that although a single threshold for hypoalbuminemia can be helpful, the severity of malnutrition remains a critical factor for patient selection, risk-stratification, and operative approach for managing femoral and inguinal hernias.
      The clinical guidelines by the American Society for Parenteral Nutrition advise against the isolated use of albumin to assess nutrition status, given that it is a marker of inflammatory metabolism.
      • Mueller C.
      • Compher C.
      • Ellen D.M.
      • et al.
      A.S.P.E.N. clinical guidelines: nutrition screening assessment, and intervention in adults.
      Reduced albumin levels secondary to inflammation may reasonably be expected in patients experiencing bowel incarceration or strangulation.
      • Kadioglu H.
      • Omur D.
      • Bozkurt S.
      • et al.
      Ischemia modified albumin can predict necrosis at incarcerated hernias.
      In the present study, a small proportion of patients were diagnosed with incarcerated or strangulated groin hernia (11.6%), with a vast majority of the cohort undergoing elective repair (93.4%). Thus, decreased albumin levels due to an inflammatory process would be unexpected for most patients in this study population. Measurements of C-reactive protein or other acute inflammatory markers as a follow-up test to low albumin levels are now nearly a standard in the multidisciplinary care of critically ill surgical patients. However, most hernia patients are not critically ill and would not warrant a C-reactive protein check. Further investigation is necessary to ascertain the clinical utility of measuring these markers to optimize groin hernia repair outcomes.
      The choice of delaying or not pursuing surgery depends on multiple factors and can be complex. Considering the risk of future hernia strangulation, albumin levels can help ascertain not only surgical timing but also potential preoperative interventions. Current literature has demonstrated mixed results regarding supplementation of exogenous perioperative albumin.
      • Golub R.
      • Sorrento J.J.
      • Cantu R.
      • Nierman D.M.
      • Moideen A.
      • Stein H.D.
      Efficacy of albumin supplementation in the surgical intensive care unit: a prospective, randomized study.
      • Mahkovic-Hergouth K.
      • Kompan L.
      Is replacement of albumin in major abdominal surgery useful?.
      • Charles A.
      • Purtill M.
      • Dickinson S.
      • et al.
      Albumin use guidelines and outcome in a surgical intensive care unit.
      Truong et al found that delaying surgical procedures to allow optimization of nutrition status, as evidenced by improved albumin levels, led to decreased mortality and morbidity after colorectal surgery.
      • Truong A.
      • Hanna M.H.
      • Moghadamyeghaneh Z.
      • Stamos M.J.
      Implications of preoperative hypoalbuminemia in colorectal surgery.
      Similar findings have been demonstrated in sleeve gastrectomy and joint arthroplasty.
      • Huang R.
      • Greenky M.
      • Kerr G.J.
      • Austin M.S.
      • Parvizi J.
      The effect of malnutrition on patients undergoing elective joint arthroplasty.
      ,
      • Al-Mulhim A.S.
      Laparoscopic sleeve gastrectomy and nutrient deficiencies: a prospective study.
      However, results from the SAFE study by Finfer et al demonstrated no difference in outcomes based on intravenous albumin supplementation.
      • Finfer S.
      • Bellomo R.
      • McEvoy S.
      • et al.
      Effect of baseline serum albumin concentration on outcome of resuscitation with albumin or saline in patients in intensive care units: analysis of data from the saline versus albumin fluid evaluation (SAFE) study.
      Similarly, Hergouth and Kompan concluded that low serum albumin levels signal an inflammatory response to surgery that cannot be altered by replacement.
      • Mahkovic-Hergouth K.
      • Kompan L.
      Is replacement of albumin in major abdominal surgery useful?.
      For elective colorectal resections, Thornblade et al recommended oral immunonutrition supplementation daily for 5 days before the operation.
      • Thornblade L.W.
      • Varghese Jr., T.K.
      • et al.
      Preoperative immunonutrition and elective colorectal resection outcomes.
      This is a reasonable approach to improve nutrition status preoperatively. Considering its cost and availability in various settings, the impact of immunonutrition in groin hernia repair merits assessment in a prospective manner. Altogether, our finding sought to inform surgeons and physicians about preoperative risk and to aid in counseling patients regarding caloric supplementation and other mechanisms to improve albumin levels. Physician-patient discussion, especially in the elective setting, would be the best approach for these operations.
      This study had several limitations, including those inherent to its retrospective nature. The majority of patients undergoing hernia repair did not have a recorded preoperative serum albumin level. We used a validated imputation method to account for missing serum albumin values. In addition, data regarding liver disease were limited in this study, which could have confounded the predictive role of malnutrition. We included preoperative bilirubin in the analysis, which was not elevated to a clinically significant degree, suggesting that liver dysfunction alone does not account for the relationship between low albumin and inferior outcomes. Furthermore, the NSQIP provides data on clinical outcomes for only 30 days following operations, which limited our analysis to short-term outcomes. As NSQIP participating hospitals are known to be higher volume teaching institutions, it is possible that hypoalbuminemia may have a greater impact on outcomes in less experienced centers. In addition, data in the NSQIP database are not verified by the ACS NSQIP and are thus subject to coding errors. Nonetheless, our study captured a large sample of groin hernia repairs and used robust statistical methodology to mitigate the impact of these limitations.
      In conclusion, preoperative hypoalbuminemia is associated with increased morbidity and mortality after open and laparoscopic groin hernia repair. Lower preoperative serum albumin levels are independently associated with increased mortality, septic shock, bleeding, pneumonia, prolonged mechanical ventilation, DVT, renal failure, reintubation, reoperation, and 30-day readmission. Although hypoalbuminemia is defined as albumin levels <3.5 g/dL, patients with serum albumin <3.0 g/dL experience an exponentially greater risk of mortality. Our findings suggested that preoperative serum albumin remains a useful predictor of postsurgical outcomes and can be used in shared decision-making and optimization of malnourished patients in need of groin hernia repair.

      Funding/Support

      Russyan Mark Mabeza was supported by the Dean’s Leadership in Health and Science Scholarship at the David Geffen School of Medicine at UCLA.

      Conflict of interest/Disclosure

      The authors have no conflicts of interests or disclosures to report.

      Supplementary Materials

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