Preoperative Laboratory Testing

Preoperative investigation practices for elective surgical patients: clinical audit

BACKGROUND

The findings of pre-operative investigations help to identify risk factors that may affect the course of surgery or post-operative recovery by contributing to informed consent conversations between the surgical team and the patient, as well as guiding surgical and anesthetic planning. Certainly, preoperative tests are valuable when they offer additional information beyond what can be gathered from a patient's history and physical examination alone. Preoperative testing practices differ significantly among hospitals, and even within the same hospital, clinicians may have varying approaches to requesting tests. This study aimed to investigate preoperative testing practices and compare them with the latest guidelines from the National Institute for Health and Care Excellence (NICE).

METHODS

This three-month institutionally based study was carried out at the Debre Tabor Comprehensive Specialized Hospital from May 1 to July 30, 2023, including individuals aged 16 years and older who were not pregnant and had undergone elective surgery in the gynecological, orthopedic, and general units. Data on the sociodemographic characteristics, the existence of comorbidities, the invasiveness of surgery, and the tests taken into consideration by the guideline were gathered using a self-administered questionnaire. After rigorously analyzing and revising the results of preoperative investigation approaches, we compared them to the standard of recommendations. Moreover, the data was analyzed and graphically presented using Microsoft Excel 2013.

RESULTS

During the data collection period, 247 elective patients underwent general, orthopedic, and gynecological operations. The majority of patients, 107 (43.32%), were between the ages of 16 and 40 and had an American Society of Anesthesiologists (ASA) class one (92.71%). 350 investigations were requested in total. Of these, 71 (20.28%) tests were ordered without a justified reason or in contravention of NICE recommendations.

CONCLUSIONS

In our hospital's surgical clinical practice, unnecessary preoperative testing is still common, especially when it comes to organ function tests, electrocardiograms (ECGs), and complete blood counts (FBCs). When deciding whether preoperative studies are required, it is critical to consider aspects including a complete patient history, a physical examination, and the invasiveness of the surgery.

Retrospective analyses of routine preoperative blood testing in a tertiary eye hospital: could Choosing Wisely work in China?

AIMS

To explore the possibility of implementing Choosing Wisely on ocular patients in China by investigating the prevalence of abnormalities in routine preoperative blood tests (RPBTs) and its turnaround time (TAT).

METHODS

Data from 102 542 ocular patients between January 2016 and December 2018, at Zhongshan Ophthalmic Center, were pooled from the laboratory information system. The test results were divided into normal and abnormal, including critical values. Ocular diseases were stratified into 11 subtypes based on the primary diagnosis. The TAT of 243 350 blood tests from January 2017 to December 2018 was categorised into transportation time and intralaboratory time.

RESULTS

RPBT was grouped into complete blood count (CBC), blood biochemistry (BBC), blood coagulation (BCG) and blood-borne pathogens (BBP), completed for 97.22%, 87.66%, 94.41% and 95.35% of the recruited patients (male, 52 549 (51.25%); median(IQR) age, 54 (29-67) years), respectively. Stratified by the test items, 9.19% (95% CI 9.07% to 9.31%) were abnormal results, and 0.020% (95% CI 0.019% to 0.022%) were critical; most abnormalities were on the CBC, while glucose was the most common critical item. Classified by the patients' primary diagnosis, 76.97% (95% CI 76.71% to 77.23%) had at least one abnormal result, and 0.28% (95% CI 0.25% to 0.32%) were critical; abnormal findings were reported in 45.29% (95% CI 44.98% to 45.60%), 54.97% (95% CI 54.65% to 55.30%), 30.29% (95% CI 30.00% to 30.58%) and 11.32% (95% CI 11.12% to 11.52%) for the CBC, BBC, BCG and BBP tests, respectively. The median transportation time and intralaboratory TAT of the samples were 12 min and 78 min respectively.

CONCLUSION

Blood abnormalities are common in ocular patients. With acceptable timelines, RPBT is still indispensable in China for patient safety.

The Dentoalveolar Surgical Patient: Perioperative Principles Based on Contemporary Controversies

Dentoalveolar surgery comprises more than 50% of the practice of oral and maxillofacial surgeons worldwide and is the most commonly performed category of surgical procedure. Optimal strategies for management of many medical problems, however, remain unclear. Remaining current on medical and surgical perioperative strategies is a standard for best practice. This article provides contemporary approaches for the perioperative management of patients presenting for dentoalveolar surgery. Attention will be directed to the perioperative management of cardiovascular disease, diabetes, and obesity. These diseases are chosen owing to controversies with respect to good scientific evidence that supports a standard of perioperative care.

Rationale and design of an evidence-based tool to guide preoperative evaluation and management

BACKGROUND

In the United States, over-testing and over-treatment are recognised causes of excess cost and patient harm. Healthcare value, defined as health outcomes achieved relative to the costs of care, has become a focus to improve the quality and affordability of healthcare.

AIM

To describe the rationale for, and development of a standardised clinical preoperative decision-support tool.Program description: An evidence-based, preoperative clinical decision tool was developed to guide preoperative testing and management of high-risk medications.Program evaluation: Patient data before and after implementation of the tool will be analysed to determine its effectiveness in reducing preoperative testing.

DISCUSSION

Preoperative testing is an area that presents an opportunity to increase healthcare value and decrease healthcare spending. Guidelines are available to standardise preoperative assessment but their adoption and acceptance into practice has been slow. To systematise preoperative assessment within our healthcare system, we reviewed current published literature and guidelines and synthesised them into an electronic, evidence-based, decision-support tool. After distribution of the tool to clinicians in our healthcare system, we will assess its impact on healthcare value, costs and outcomes. We believe that an evidence-based preoperative tool, seamlessly and efficiently integrated into clinician workflow, can improve preoperative patient care.

Routine Postoperative Hemoglobin Assessment Poorly PredictsTransfusion Requirement among Patients Undergoing Minimally Invasive Radical Prostatectomy

Introduction

An advantage of minimally invasive radical prostatectomy over open surgery is decreased blood loss. At our institution hemoglobin is routinely checked 4 and 14 hours postoperatively. We assessed the relevance of this practice in a contemporary cohort undergoing minimally invasive radical prostatectomy.

Methods

We retrospectively reviewed data from patients undergoing laparoscopic or robotic radical prostatectomy at our institution between January 2010 and September 2018. We identified 3,631 patients with preoperative and postoperative hemoglobin values, and assessed the role of routine hemoglobin assessment in determining need for transfusion within 30 days. Medicare reimbursement rates for 2019 were used for cost analysis.

Results

Of 3,631 patients in our cohort 44 (1.2%) required transfusion. At 4 hours following surgery the median hemoglobin decrease was 8.0% (IQR 4.8 to 11.4) for patients who did not receive transfusion and 12.5% (9.5 to 19.2) for those who received transfusion. At 14 hours the median decrease was 14.2% (IQR 10.0 to 18.4) vs 33.1% (22.6 to 38.6). Routine hemoglobin assessment had no role in the decision to transfuse in 18 patients (41%). No patient was transfused based on 4-hour values alone. Omitting 1 hemoglobin assessment could have resulted in institutional savings of $37,000 during this period.

Conclusions

As transfusion following minimally invasive radical prostatectomy is rare, scheduled postoperative hemoglobin assessments in the absence of symptoms are unnecessary to recognize bleeding events. The largest hemoglobin difference between men who did vs did not receive transfusion was seen at 14 hours postoperatively. Thus, this single hemoglobin evaluation is sufficient.

Preoperative laboratory testing: Implications of "Choosing Wisely" guidelines

Preoperative laboratory testing is often necessary and can be invaluable for diagnosis, assessment, and treatment. However, performing routine laboratory tests for patients who are considered otherwise healthy is not usually beneficial and is costly. It is estimated that $18 billion (U.S.) is spent annually on preoperative testing, although how much is wasteful remains unknown. Ideally, a targeted and comprehensive patient history and physical exam should largely determine whether preprocedure laboratory studies should be obtained. Healthcare providers, primarily anesthesiologists, should remain cost-conscious when ordering specific laboratory or imaging tests prior to surgery based on available literature. We review the overall evidence and key points from the Choosing Wisely guidelines, the identification of potential wasteful practices, possible harms of testing, and key clinical findings associated with preoperative laboratory testing.

Utility of preoperative laboratory evaluation in low-risk patients undergoing hysterectomy for benign indications

OBJECTIVE

To evaluate whether preoperative laboratory tests are predictive of surgical complications in the first 30 days after benign hysterectomy.

STUDY DESIGN

Data was collected from the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) of patients undergoing benign hysterectomy between 2014 and 2016. Patients with significant medical comorbidities were excluded except for current smoking and hypertension. Patients were stratified into those who did and did not undergo preoperative testing. Laboratory results were stratified into normal and abnormal values. The primary outcome was the composite complication rate between groups. Student'st-test, Fisher's exact test, and Wilcoxon Rank-Sum were used for statistical analysis where appropriate. Multivariable regression analysis was used to determine which variables were independently predictive of postoperative complications.

RESULTS

A total of 24,752 patients met all inclusion criteria. Of these, 92.5% had at least one preoperative test performed, and out of those 33.5% had an abnormal value. The most common test performed was a complete blood count, 92.5%, and the least common were coagulation studies, 16.1%. Patients who underwent testing were younger (45.9 vs 47.8 years, p < 0.001), more likely to smoke (15.3% vs 12.7%, p = 0.004) and less likely to have hypertension (18.9% vs 21.8%, p = 0.001). The most common abnormality was a low hematocrit, and the least common anomaly was an elevated international normalized ratio. The total complication rate was 9.2%, and there were no differences between groups (p = 0.07). The only lab value associated with an increased risk of complications was a hematocrit less than 34.9% (aOR 2.74, 95%CI 2.92-3.79) and WBC count >11 thousand per microliter (aOR 2.11, 95%CI 1.53-3.09).

CONCLUSION

Non-hematologic preoperative laboratory anomalies are uncommon in healthy women undergoing benign hysterectomy by any modality and furthermore non-hematologic abnormalities are not predictive of post-operative complications. On the other hand, hematologic abnormalities are fairly common and a WBC above 11 cells per uL and hematocrit below 34.9% are predictive of postoperative complications.

Expert Recommendations on Frequency of Utilization of Common Laboratory Tests in Medical Inpatients: a Canadian Consensus Study

BACKGROUND

Repetitive inpatient laboratory testing in the face of clinical stability is a marker of low-value care. However, for commonly encountered clinical scenarios on medical units, there are no guidelines defining appropriate use criteria for laboratory tests.

OBJECTIVE

This study seeks to establish consensus-based recommendations for the utilization of common laboratory tests in medical inpatients.

DESIGN

This study uses a modified Delphi method. Participants completed two rounds of an online survey to determine appropriate testing frequencies for selected laboratory tests in commonly encountered clinical scenarios. Consensus was defined as agreement by at least 80% of participants.

PARTICIPANTS

Participants were 36 experts in internal medicine across Canada defined as internists in independent practice for ≥ 5 years with experience in medical education, quality improvement, or both. Experts represented 8 of the 10 Canadian provinces and 13 of 17 academic institutions.

MAIN MEASURES

Laboratory tests and clinical scenarios included were those that were considered common on medical units. The final survey contained a total of 45 clinical scenarios looking at the utilization of six laboratory tests (complete blood count, electrolytes, creatinine, urea, international normalized ratio, and partial thromboplastin time). The possible frequency choices were every 2-4 h, 6-8 h, twice a day, daily, every 2-3 days, weekly, or none unless there was specific diagnostic suspicion. These scenarios were reviewed by two internists with training in quality improvement and survey methods.

KEY RESULTS

Of the 45 initial clinical scenarios included, we reached consensus on 17 scenarios. We reached weak consensus on an additional 19 scenarios by combining two adjacent frequency categories.

CONCLUSIONS

A Canadian expert panel of internists has provided frequency recommendations on the utilization of six common laboratory tests in medical inpatients. These recommendations need validation in prospective studies to assess whether restrictive versus liberal laboratory test ordering impacts patient outcomes.

Routine Preoperative Coagulation Tests in Children Undergoing Elective Surgery or Invasive Procedures: Are They Still Necessary?

Introduction:

Preoperative coagulation screening tests in pediatric patients was once routine clinical practice globally and still used as standard practice in some countries before surgical procedures to assess of perioperative bleeding risk.

Objective:

The study aimed to evaluate unselected routine preoperative coagulation testing in children undergoing elective or invasive surgery to predict abnormal perioperative bleeding. The study also aimed to provide a rational approach of determining bleeding and family history of coagulation disorders as a predictive risk for bleeding.

Methods:

This retrospective study conducted between 2014 and 2015 (1 year) on normal healthy children aged under 15 years admitted to the hospitals for elective mild to intermediate surgery or invasive procedures. We reviewed and collected the details of the clinical history, previous surgery, trauma, family history, detail of anti-thrombotic medication and coagulation tests performed (prothrombin time (PT), the activated partial prothrombin time (APTT), and international normalized ratio (INR)) at the time of admission.

Results:

Among 2078 cases, 1940 cases had normal coagulation tests (93.4%), 77 cases had abnormal coagulation results (3.7%), and 61 patients underwent surgery without preoperative coagulation screening (2.9%). In 15 of 77 patients, coagulation tests were normal on repeat testing. A total of 52 were confirmed to have abnormal screening testing. Among these 52 cases, 45 had normal factors assay; where seven patients had abnormal factors assay. Postoperative bleeding occurred only in three cases (0.14%), two cases due to surgical procedures with normal preoperative testing and one due to hemophilia A which was detected postoperatively as no preoperative testing was performed.

Conclusions:

Routine coagulation screening before surgery or invasive procedures to predict perioperative bleeding in unselected patients is not recommended. Our study emphasizes that selective preoperative testing is more appropriate. Selective criteria for consideration of the latter includes physical examination, type of surgery, family and bleeding history, and concomitant use of antiplatelet and anti-thrombotic therapy.

Preoperative Laboratory Testing

Obtaining routine preoperative laboratory tests increases health care costs and has been listed, by the Choosing Wisely Campaign, as one of the top 5 practices anesthesiologists should avoid. Routine testing without clinical indication is not cost-effective and could cause harm and unnecessary delays. Abnormal findings are more likely to be false positive and costly to pursue, introduce new risks, and increase anxiety for the patient. Preoperative testing need to be performed only following a targeted history and physical examination, factoring severity of surgery, and comorbidities such that the benefit of the test outweighs risk.

Clinical Utility of Routine Preoperative Laboratory Assessment in a Urogynecologic Population

OBJECTIVE

The objective of this study was to determine the incidence of newly diagnosed, clinically meaningful laboratory abnormalities on routine preoperative laboratory testing in women undergoing urogynecologic surgery.

METHODS

All urogynecologic cases performed at a single institution over a 3-year period were reviewed. Women undergoing major surgery routinely had a basic metabolic panel, complete blood count (CBC), and type and screen, whereas women undergoing minor surgery had testing at the surgeon's discretion. Demographics, surgical details, preoperative laboratory values, and instances of postoperative transfusion were abstracted. If testing revealed a clinically meaningful abnormality, physician notes were reviewed to determine whether the abnormality was previously known or led to surgical postponement.

RESULTS

A total of 836 cases were identified: 411 major (49%) and 425 minor (51%). Patients had a mean ± SD age of 57 ± 13 years and body mass index of 27 ± 6 kg/m. Medical comorbidities were hypertension, 38%; diabetes, 24%; chronic kidney disease, 3%; and congestive heart failure, 4%; 89% had an American Society of Anesthesiologists class of less than or equal to 2. A total of 453 (54%) had preoperative CBC, and 367 (44%) had preoperative basic metabolic panel. Six (1.3%) new abnormalities (hemoglobin between 8.0 and 10.0) were identified on CBC. Thirty-one women had elevated creatinine level (>1.0), and 28 (90%) of these had a history of hypertension. No surgeries were postponed or changed owing to anemia, thrombocytopenia, or renal dysfunction. No clinically significant electrolyte abnormalities were identified. Type and screen were collected on 394 patients; none were transfused intraoperatively.

CONCLUSIONS

Routine preoperative laboratory testing does not identify clinically meaningful abnormalities or alter surgical management in women undergoing urogynecologic surgery.

Preoperative anesthesia evaluation

The preoperative evaluation is the first step in ensuring the safe conduct of anesthetic care in pediatric patients of all ages. Over time, this process has changed significantly from a time when patients were admitted to the hospital the night before surgery to a time when the majority of patients, including those scheduled for major surgical procedures, arrive the day of surgery. For most patients, the preoperative examiantion can be conducted over the phone by a trained nurse or on-line via a survey thereby eliminating the need for a separate visit merely for the preoperative evaluation. Regardless of where or how it occurs, the goals of the preoperative evaluation are to gain information regarding the patient's current status, comorbid conditions, and the intended procedure. This process allows the identification of patients who require additional preoperative testing or those patients who need to be seen by an anesthesiolgoist prior to the day of surgery. During the preopeative evalaution, decisions are made regarding further laboratory or investigative work-up that are required. The preoperative meeting provides an arena to develop the initial parent-physcian rapport, outline anesthetic risks, and discuss the intended anesthetic plan including options for postoperative analgesia. The process facilitates the care of patients during the perioperative period while limiting surgical cancellations resulting from patient-related issues. The following chapter reviews the essential components of the preoperative evaluation including the appropraite use of preoperative laboratory testing and other investigative procedures including radiologic imaging. Key components of the physical examinatino including the airway examination are reviewed.

Utility of routine laboratory preoperative tests based on previous results: Time to give up

Introduction

The usefulness and cost-effectiveness of routine laboratory preoperative tests (POTs) have been challenged recently. In fact, the American Society of Anesthesiologists (ASA) Task Force has stated that test results obtained from the medical record within 6 months of surgery generally are mostly acceptable. The aim of our study was to evaluate the degree of utility of POTs and their clinical benefit based on this recommendation.

Material and methods

We studied retrospectively every routine POT request from 8 randomly selected weeks in 2016. Every POT contained glucose, creatinine, haemoglobin and coagulation tests (PT-INR). Each pathological result for these tests was registered and classified as “expected” (if previous pathological result within 6 months existed for that test) or “unexpected” (if previous pathological result within 6 months did not exist for that test). Results of ASA physical status classification (a system for assessing the fitness of patients before surgery) and changes in patient management after POTs were retrieved from medical history as well.

Results

A total of 4516 tests (from 1129 patients) were analysed and 498 results were found pathological (11%). Of these, 403 were expected (8.9%) and 95 unexpected (2.1%). There was not any change in anaesthetic management for any patient due to these findings.

Conclusions

Routine POTs are an inefficient and low-value service. POTs have to be always ordered selectively after a previous consideration of specific information obtained from several sources (medical records, interviews, examinations, type of surgery) and only if the information obtained will result in changes in the management of the patient.

A bleeding assessment tool correlates with intraoperative blood loss in children and adolescents undergoing major spinal surgery

Screening laboratory studies for bleeding disorders are of little predictive value for operative bleeding risk in adults. Predicting perioperative bleeding in pediatric patients is particularly difficult as younger patients often have not had significant hemostatic challenges. This issue is distinctly important for high bleeding risk surgeries, such as major spinal procedures. The aim of this study was to determine if the score of a detailed bleeding questionnaire (BQ) correlated with surgical bleeding in pediatric patients undergoing major spinal surgery. A total of 220 consecutive pediatric patients (mean age 14.2years) undergoing major spinal surgery were administered the BQ preoperatively, as well as having routine screening laboratory studies (i.e., PT, aPTT, PFA) drawn. A retrospective analysis was conducted to determine if there was a correlation between either the results of the BQ and/or laboratory studies with operative outcomes. A BQ score>2 showed a strong positive correlation with intraoperative bleeding based on both univariate and multivariate analyses. In contrast, abnormalities in screening laboratory studies showed no significant correlation with operative bleeding outcomes. Relying on screening laboratory studies alone is inadequate. The BQ used here correlated with increased intraoperative hemorrhage, suggesting this tool may be useful for assessing pediatric surgical bleeding risk, and may also be useful in identifying a subset of patients with a very low bleeding risk that may not require laboratory screening.

Percutaneous Nephrolithotomy in Rare Bleeding Disorders: A Case Report and Review of the Literature

Surgery in patients with congenital or acquired coagulation defects has always been challenging and requires special care with a multidisciplinary approach. Percutaneous nephrolithotomy (PCNL) is a standard procedure performed in patients with kidney stones. Although prone to bleeding more than most of the widely performed surgical procedures, there are not much data regarding PCNL in patients with bleeding disorders or coagulation defects. There are only case reports or series with a small number of patients for the patients with common coagulation defects, including hemophilias. Moreover, there are no reports about PCNL in rare bleeding disorders. In this study, we reported a case referred for kidney stone treatment and diagnosed as Factor VII deficiency during preoperative evaluation. Because it is one of the rare bleeding disorders, we also reviewed the literature in this field.