Using days alive and out of hospital to measure surgical outcomes in New Zealand: a cross-sectional study

OBJECTIVES

To measure differences at various deciles in days alive and out of hospital to 90 days (DAOH₉₀) and explore its utility for identifying outliers of performance among district health boards (DHBs).

METHODS

Days in hospital and mortality within 90 days of surgery were extracted by linking data from the New Zealand National Minimum Data Set and the births and deaths registry between 1 January 2011 and 31 December 2021 for all adults in New Zealand undergoing acute laparotomy (AL-a relatively high-risk group), elective total hip replacement (THR-a medium risk group) or lower segment caesarean section (LSCS-a low-risk group). DAOH₉₀ was calculated without censoring to zero in cases of mortality. For each DHB, direct risk standardisation was used to adjust for potential confounders and presented in deciles according to baseline patient risk. The Mann-Whitney U test assessed overall DAOH₉₀ differences between DHBs, and comparisons are presented between selected deciles of DAOH₉₀ for each operation.

RESULTS

We obtained national data for 35 175, 52 032 and 117 695 patients undergoing AL, THR and LSCS procedures, respectively. We have demonstrated that calculating DAOH without censoring zero allows for differences between procedures and DHBs to be identified. Risk-adjusted national mean DAOH₉₀ Scores were 64.0 days, 79.0 days and 82.0 days at the 0.1 decile and 75.0 days, 82.0 days and 84.0 days at the 0.2 decile for AL, THR and LSCS, respectively, matching to their expected risk profiles. Differences between procedures and DHBs were most marked at lower deciles of the DAOH₉₀ distribution, and outlier DHBs were detectable. Corresponding 90-day mortality rates were 5.45%, 0.78% and 0.01%.

CONCLUSION

In New Zealand after direct risk adjustment, differences in DAOH₉₀ between three types of surgical procedure reflected their respective risk levels and associated mortality rates. Outlier DHBs were identified for each procedure. Thus, our approach to analysing DAOH₉₀ appears to have considerable face validity and potential utility for contributing to the measurement of perioperative outcomes in an audit or quality improvement setting.

A protocol for a prospective, multicentre observational study to determine if nonanaemic iron deficiency worsens postoperative outcome in patients undergoing elective surgery for resection of colorectal cancer: The NATO study

BACKGROUND

Preoperative absolute and functional iron deficiency anaemia is associated with poor postoperative outcomes in patients undergoing surgery for colorectal cancer. It is biologically plausible that "early", or "nonanaemic" iron deficiency may also be associated with worse postoperative outcomes in similar cohorts, albeit at lesser severity than that seen for anaemia. The evidence supporting this assertion is of low quality.

METHODS

We have designed a prospective, observational study to delineate associations between preoperative non-anaemic iron deficiency and postoperative outcomes after surgery for colorectal cancer. Patients without anaemia, undergoing elective surgery for colorectal cancer will be allocated to an iron replete or an iron deficient group based on preoperative transferrin saturation. The primary outcome is days alive and at home on postoperative day 90. Secondary outcomes include days alive and at home on postoperative day 30, length of hospital stay, readmission to acute care, postoperative complications, health-related quality of life scores, quality of postoperative recovery, and requirement for allogeneic blood transfusion. The planned sample size is 422 patients, which has 80% power to detect a two-day difference in the primary outcome. The study commenced in May 2019.

CONCLUSION

The results of this study will provide patients and clinicians with high-quality evidence concerning associations between nonanaemic iron deficiency and patient-centred outcomes after surgery for colorectal cancer. The study will be conducted in multiple urban and rural centres across Australia and New Zealand. The results will be highly generalisable to contemporary surgical practice and should be rapidly translated.

Iron deficiency screening is a key issue in chronic inflammatory diseases: A call to action

Iron deficiency is frequent in patients with chronic inflammatory conditions (e.g., chronic heart failure, chronic kidney disease, cancers, and bowel inflammatory diseases). Indeed, high concentrations of inflammatory cytokines increase hepcidin concentrations that lead to the sequestration of iron in cells of the reticuloendothelial system (functional iron deficiency). Iron parameters are often assessed only in the context of anemia, but iron deficiency, even without anemia, is present in about half of patients with inflammatory conditions. Iron deficiency worsens underlying chronic diseases and is an independent factor of morbidity and mortality. In daily practice, the most effective biomarkers of iron status are serum ferritin, which reflects iron storage, and transferrin saturation, which reflects the transport of iron. Serum ferritin is increased in an inflammatory context, and there is still no consensus on the threshold to be used in chronic inflammatory conditions. Nevertheless, recent recommendations of international guidelines agreed to define iron deficiency by serum ferritin <100 µg/L and/or transferrin saturation <20%. Iron parameters remain, however, insufficiently assessed in patients with chronic inflammatory conditions. Indeed, clinical symptoms of iron deficiency, such as fatigue, are not specific and often confused with those of the primary disease. Iron repletion, preferably by the intravenous route to bypass tissue sequestration, improves clinical signs and quality of life. Because of the negative impact of iron deficiency on chronic inflammatory diseases and the efficacy of intravenous iron repletion, screening of iron parameters should be part of the routine examination of all patients with chronic inflammatory diseases.

Perioperative changes in haemoglobin and ferritin concentrations from preoperative intravenous iron isomaltoside for iron deficiency anaemia in patients with colorectal cancer: A pilot randomised controlled trial

Background

Patients with colorectal cancer have a high risk of iron deficiency anaemia (IDA) due to chronic tumour induced blood loss, a reduced dietary iron intake from poor nutrition or gastrointestinal malabsorption. This pilot, double blinded, randomised controlled trial (RCT) examined the effect and feasibility of using preoperative iron isomaltoside for treating iron deficiency anaemia.

Methods

Forty eligible adults with IDA were randomised to receive either intravenous iron isomaltoside (20 mg.kg^-1 up to 1000 mg over 30 minutes) or usual preoperative care (control) three weeks before scheduled colorectal surgery. The primary outcomes were perioperative changes in haemoglobin and ferritin concentrations.

Results

The recruitment rate was 78% of all eligible referred patients (1.9 patients/month). The haemoglobin and ferritin concentrations were higher in the iron isomaltoside group than the control group over the perioperative period (group*time interaction P = 0.042 and P < 0.001 respectively). Mean haemoglobin change from baseline to before surgery was higher in the iron isomaltoside group (7.8, 95% CI: 3.2 to 12.3 g.l^-1) than the control group (1.7, 95% CI: -1.9 to 5.3 g.l^-1) [mean difference 6.1, 95% CI: 0.3 to 11.8 g.l^-1; P = 0.040]. The ferritin change from baseline to before surgery between groups was large in favour of the iron isomaltoside group (mean difference 296.9, 95% CI: 200.6 to 393.2 μg.l^-1; P < 0.001]. There were no differences between groups in packed red blood cell transfusions needed, surgical complications, quality of recovery and days (alive and) at home within 30 days after surgery.

Conclusion

Iron isomaltoside therapy was safe and had a minimal effect on perioperative changes in haemoglobin concentration. Given the slow recruitment and new evidence emerging during the conduct of this study, conducting a multi-centre RCT based on the current pilot trial protocol is unlikely to be feasible.

Trial registration

ClinicalTrials.gov NCT03565354.

Preoperative Intravenous Iron Treatment in Colorectal Cancer: Experience From Clinical Practice

INTRODUCTION

Anemia is associated with increased postoperative morbidity and mortality in abdominal surgery. In clinical trials, preoperative i.v. iron treatment increases the preoperative hemoglobin (Hb) concentration but the effect on transfusion rates are not consistent. This study reports on the experience with preoperative i.v. iron treatment in surgical colorectal cancer (CRC) patients in clinical practice.

METHODS

A registry-based cohort study. Surgical colorectal cancer patients with iron deficiency anemia were compared after division into two groups; those who preoperatively received i.v. iron treatment and those who did not. Primary outcomes were preoperative changes in Hb and the difference in perioperative red blood cell transfusion (RBCT) rates. Postoperative complications and mortality rates were analyzed and a descriptive analysis on what triggered blood transfusions were performed.

RESULTS

A total of 170 patients were included. Of these, 122 had received preoperative i.v. iron treatment and 48 had not. The perioperative transfusion rate was 45% (55/122) in the treatment group and 40% (19/48) in the control group (non-significant difference). The preoperative changes in Hb levels were not different between the two groups. Transfusion practice appeared more liberal and preceded by higher Hb levels that was guided by the National transfusion guideline. I.v. iron treated patients had a higher rate of postoperative complications. No differences were found on length of stay (LOS) or postoperative mortality.

CONCLUSIONS

Preoperative i.v. iron treatment was neither associated with a rise in Hb concentrations at the time of surgery, nor with a reduction in the likelihood of receiving perioperative red blood cell transfusions (RBCT) in colorectal cancer (CRC) patients with iron deficiency anemia.

Hematinic and Iron Optimization in Peri-operative Anemia and Iron Deficiency

Purpose of Review

Preoperative anemia is independently associated with worse postoperative outcomes following cardiac and noncardiac surgery. This article explores the current understanding of perioperative anemia and iron deficiency with reference to definition, diagnosis, and treatment.

Recent Findings

Iron deficiency is the most common cause of anemia. It can arise from reduced iron intake, poor absorption, or excess iron loss. Inflammation throughout the preoperative period can drive iron sequestration, leading to a functional deficiency of iron and the development of what was referred to until recently as the “anemia of chronic disease.” Current best practice guidance supports the routine administration of preoperative intravenous iron to treat anemia despite limited evidence. This “one size fits all” approach has been called into question following results from a recent large, randomized trial (the PREVENTT trial) that assessed the use of a single dose of intravenous iron compared to placebo 10–42 days before major abdominal surgery. Although there were no improvements in patient-centered outcomes apparent during the initial hospital stay, secondary endpoints of this trial suggested there may be some late benefit after discharge from the hospital (8 weeks postoperatively). This trial raises questions on (1) the mechanisms of iron deficiency in the perioperative patient; (2) the need to reassess our opinions on generic anemia management; and (3) the need to address patient outcomes after discharge from hospital.

Summary

Despite the known associations between preoperative anemia (particularly iron deficiency anemia) and poor postoperative outcome, recent evidence suggests that administering intravenous iron relatively close to surgery does not yield a tangible short-term benefit. This is made more complex by the interplay between iron and innate immunity. Iron deficiency irrespective of hemoglobin concentration may also impact postoperative outcomes. Therefore, further research into associations between iron deficiency and postoperative outcomes, and between postoperative anemia, delayed outcomes (hospital readmission), and the efficacy of postoperative intravenous iron is required.

Iron deficiency anaemia in pregnancy: A contemporary review

Iron deficiency anaemia is a global health problem, which particularly affects pregnant women. Iron deficiency anaemia during pregnancy is associated with increased maternal and perinatal morbidity and mortality. Maternal iron deficiency may also be associated with neurocognitive deficits in infants. Iron requirements increase during pregnancy and are influenced by hepcidin, the master regulator of iron homeostasis. The enduring global burden of maternal anaemia suggests that currently employed iron supplementation strategies are suboptimal. Recent developments in our understanding of systemic and placental iron homeostasis may improve therapeutic effectiveness by altering the dose and frequency of oral iron. Intravenous iron appears to be a safe treatment to correct maternal anaemia rapidly but research on patient-centred outcomes and cost-effectiveness is needed. Future trials should be adequately powered to assess outcomes relevant to pregnant women.

Anaemia and its impact on colorectal cancer patients: how can we better optimize surgical outcomes?

BACKGROUND

Anaemia is a common manifestation of colorectal cancer (CRC). However, appropriate workup prior to surgery and the effect of anaemia on outcomes have not been well defined. This study aimed to describe preoperative anaemia incidence, investigations performed, treatment and associated complications in a CRC surgical population at a single large tertiary institution in Australia.

METHODS

Patients who received surgery with curative intent for CRC between 2012 and 2017 were identified from a prospectively maintained database. Demographic and clinical outcome data were analysed.

RESULTS

In total, 754 patients with CRC were included. Anaemia was found in 350 (46.4%) patients, of which 124 (35.4%) were microcytic, 20 (5.7%) were macrocytic and 206 (58.9%) were normocytic. Older patients were more likely to have anaemia (mean age 70.28 years, standard deviation (SD) 12.98 versus 64.74 years, SD 11.74). Only 89 patients (25.4%) were tested for iron deficiency, and of these, 76 (85.4%) were found to be iron deficient and 42 (47.7%) had low ferritin. Preoperative anaemia was associated with a higher incidence of postoperative complications (adjusted odds ratio (OR) 1.46, 95%, CI 1.04-2.05; P = 0.03) and a longer length of stay (LOS; average 1.8 days; 95% CI 0.3-3.3 days).

CONCLUSION

A significant proportion of CRC patients had anaemia and the majority were normocytic. Only a small number of anaemic patients were tested for iron deficiency. Preoperative anaemia had an adverse effect on LOS and postoperative complications. The evaluation of anaemic patients is essential in CRC patients undergoing surgery.

The effect of iron deficiency and anaemia on women's health

Iron deficiency and anaemia are global health problems and major causes of morbidity in women. Current definitions of anaemia in women are historic and have been challenged by recent data from observational studies. Menstrual loss, abnormal uterine bleeding and pregnancy put women at risk of developing iron deficiency which can result in severe fatigue, reduced exercise capacity and poor work performance. Iron deficiency and anaemia during pregnancy are associated with adverse maternal and fetal outcomes, including neurocognitive deficits in children born to iron-deficient mothers. Both iron deficiency and anaemia are common in women undergoing surgery but their association with poor outcomes remains uncertain. The enduring burden of iron deficiency and anaemia in women suggests that current strategies for recognition, prevention and treatment are limited in their utility. Improvements in our understanding of iron homeostasis and the development of new iron preparations, which are better absorbed with fewer side-effects, may improve therapeutic effectiveness of oral iron. Intravenous iron is efficacious for correcting anaemia rapidly but high-quality data on patient-centred outcomes and cost-effectiveness are currently lacking. Many recommendations for the treatment of iron deficiency and anaemia in national guidelines are not supported by high-quality evidence. There is a need for robust epidemiological data and well-designed clinical trials. The latter will require collaborative working between researchers and patients to design studies in ways that incorporate patients' perspectives on the research process and target outcomes that matter to them.

Iron deficiency after kidney transplantation

Iron deficiency (ID) is highly prevalent in kidney transplant recipients (KTRs) and has been independently associated with an excess mortality risk in this population. Several causes lead to ID in KTRs, including inflammation, medication and an increased iron need after transplantation. Although many studies in other populations indicate a pivotal role for iron as a regulator of the immune system, little is known about the impact of ID on the immune system in KTRs. Moreover, clinical trials in patients with chronic kidney disease or heart failure have shown that correction of ID, with or without anaemia, improves exercise capacity and quality of life, and may improve survival. ID could therefore be a modifiable risk factor to improve graft and patient outcomes in KTRs; prospective studies are warranted to substantiate this hypothesis.

Patient Blood Management for primary hip and knee replacement. A survey among POWER.2 study researchers

BACKGROUND

Implementation of Patient Blood Management programs remain variable in Europe, and even in centres with well-established PBM programs variability exists in transfusion practices.

OBJECTIVES AND METHODS

We conducted a survey in order to assess current practice in perioperative Patient Blood Management in patients undergoing total hip and knee replacement among researchers involved in POWER.2 Study in Spain (an observational prospective study evaluating enhanced recovery pathways in orthopaedic surgery).

RESULTS

A total of 322 responses were obtained (37.8%). Half of responders check Haemoglobin levels in patients at least 4 weeks before surgery; 35% treat all anaemic patients, although 99.7% consider detection and treatment of preoperative anaemia could influence the postoperative outcomes. Lack of infrastructure (76%) and lack of time (51%) are the main stated reasons not to treat anaemic patients. Iron status is routinely checked by 19% before surgery, and 36% evaluate it solely in the anaemic patient. Hb<9.9 g/dl is the threshold to delay surgery for 61% of clinicians, and 22% would consider transfusing preoperatively clinically stable patients without active bleeding. The threshold to transfuse patients without cardiovascular disease is 8 g/dl for 43%, and 7 g/dl for 34% of the responders; 75% of clinicians consider they use "restrictive thresholds", and 90% follow the single unit transfusion policy.

CONCLUSIONS

The results of our survey show variability in clinical practice in Patient Blood Management in major orthopaedic surgery, despite being the surgery with the greatest tradition in these programs.

Intravenous iron therapy for non-anaemic, iron-deficient adults

BACKGROUND

Iron deficiency is one of the most common nutritional deficiencies, and has a number of physiological manifestations. Early, or non-anaemic iron deficiency can result in fatigue and diminished exercise capacity. Oral iron preparations have a high incidence of intolerable side effects, and are ineffective in certain forms of iron deficiency. Consequently, intravenous iron preparations are increasingly used in the treatment of non-anaemic iron deficiency. The newer, more stable iron preparations in particular purport to have a lower incidence of side effects, and are now used across a range of different patient populations.

OBJECTIVES

To assess the effects of intravenous iron therapy in the treatment of adults with non-anaemic iron deficiency.

SEARCH METHODS

On 18 October 2019 we electronically searched CENTRAL, MEDLINE, Embase, two further databases and two trials registries 2019. We handsearched the references of full-text extracted studies, and contacted relevant study authors for additional data.

SELECTION CRITERIA

We included randomised controlled trials that compared any intravenous iron preparation to placebo in adults. We excluded other forms of comparison such as oral iron versus placebo, intramuscular iron versus placebo, or intravenous iron studies where other iron preparations were used as the comparator. We also excluded studies involving erythropoietin therapy or obstetric populations.

DATA COLLECTION AND ANALYSIS

Two review authors screened references for eligibility, extracted data and assessed risk of bias. We resolved differences in opinion through discussion and consensus, and where necessary, involved a third review author to adjudicate disputes. We contacted study authors to request additional data where appropriate. The primary outcome measures were haemoglobin concentration at the end of follow-up, and quality-of-life scores at end of follow-up. Secondary outcome measures were serum ferritin, peak oxygen consumption (as measured by cardiopulmonary exercise testing), adverse effects (graded as mild to moderate and severe) and bacterial infection. We pooled data for continuous outcomes, which we then reported as mean differences (MDs) with 95% confidence intervals (CIs). We reported quality-of-life metrics as standardised mean difference (SMD), and then converted them back into a more familiar measure, the Piper Fatigue Scale. We analysed dichotomous outcomes as risk ratios (RRs). Given an expected degree of heterogeneity, we used a random-effects model for all outcomes. We performed the analysis with the software package Review Manager 5.

MAIN RESULTS

This review includes 11 studies with 1074 participants. Outcome metrics for which data were available (haemoglobin concentration, quality-of-life scores, serum ferritin, peak oxygen consumption and mild to moderate adverse effects) were similar across the included studies. The incidence of severe adverse events across all studies was zero. None of the studies measured bacterial infection as a specific outcome metric. Substantial heterogeneity influenced the results of the meta-analysis, arising from differing patient populations, definitions of iron deficiency, iron preparations and dosing regimens, and time to end of follow-up. Consequently, many outcomes are reported with small group sizes and wide confidence intervals, with a subsequent downgrading in the quality of evidence. The level of bias in many included studies was high, further reducing confidence in the robustness of the results. We found that intravenous iron therapy may lead to a small increase in haemoglobin concentration of limited clinical significance compared to placebo (MD 3.04 g/L, 95% CI 0.65 to 5.42; I2 = 42%; 8 studies, 548 participants; low-quality evidence). Quality-of-life scores (Piper Fatigue Scale MD 0.73, 95% CI 0.29 to 1.18; I2 = 0%; studies = 3) and peak oxygen consumption (MD 2.77 mL/kg/min, 95% CI -0.89 to 6.43; I2 = 36%; 2 studies, 32 participants) were associated with very low-quality evidence, and we remain uncertain about the role of intravenous iron for these metrics. We were unable to present pooled estimates for the outcomes of serum ferritin at the end of follow-up or mild to moderate adverse effects due to extreme statistical heterogeneity. Ultimately, despite the results of the meta-analysis, the low- or very low-quality evidence for all outcomes precludes any meaningful interpretation of results beyond suggesting that further research is needed. We performed a Trial Sequential Analysis for all major outcomes, none of which could be said to have reached a necessary effect size.

AUTHORS' CONCLUSIONS

Current evidence is insufficient to show benefit of intravenous iron preparations for the treatment of non-anaemic iron deficiency across a variety of patient populations, beyond stating that it may result in a small, clinically insignificant increase in haemoglobin concentration. However, the certainty for even this outcome remains limited. Robust data for the effectiveness of intravenous iron for non-anaemic iron deficiency is still lacking, and larger studies are required to assess the effect of this therapy on laboratory, patient-centric, and adverse-effect outcomes.