An Analysis of Postoperative Complications in Medialization Thyroplasty: NSQIP Data.

INTRODUCTION: Medialization thyroplasty is a procedure indicated for treatment of impaired vocal fold movement. The purpose of this study was to identify variables associated with length of hospital stay (LOS), reoperation, and readmission in patients who underwent a medialization thyroplasty procedure for unilateral vocal cord paralysis. METHODS: Adults who underwent unilateral medialization thyroplasty were identified using the 2017 to 2019 NSQIP databases via Current Procedural Terminology code 31591. Data collected included patient demographics, comorbidities, preoperative labs, American Society of Anesthesiologists classification, inpatient status, operative length, and complications. Univariate and multivariate logistic regression were used to analyze effects on total LOS, reoperation, and readmission. RESULTS: 320 patients were identified, with a mean age of 61 years (95% Cl 59.4-62.7) and a female-to-male ratio of 1.1:1. Forty-two (13.1%) patients reported dyspnea as a preoperative symptom. Seven patients (2.2%) reported postoperative complications, 2 with multiple complications: 2 surgical site infections, 2 pneumonias, 2 unplanned intubations, 2 myocardial infarctions, 1 septic shock, 1 cardiac arrest, 1 ventilator use (>48 h), and 1 acute renal failure. Fifty-one (15.9%) were inpatient procedures, with a mean LOS of 1.43 days (95% CI 0.92-1.94). Preoperative functional status and bilirubin were significantly associated with longer LOS (p < 0.001). There were 6 (1.9%) readmissions and 2 (0.6%) reoperations. In univariate analysis, dyspnea varied with reoperation which is important to note in this patient population with glottic insufficiency. CONCLUSION: Medialization thyroplasty is a procedure with a low risk of mortality. However, preexisting patient comorbidities are associated with an increased risk of postoperative complications and an increased length of stay.

The association of lifetime physical inactivity with head and neck cancer: a hospital-based case-control analysis.

Despite mounting epidemiological evidence suggesting an inverse association between recreational physical activity and cancer risk, evidence associated with head and neck cancer is scant. We conducted a case-control analysis to examine the associations of lifetime physical inactivity with the risk of head and neck squamous cell carcinoma (HNSCC). We utilized data from the Patient Epidemiology Data System at Roswell Park Cancer Institute (RPCI). Participants included 246 patients with HNSCC and 504 cancer-free controls who received medical services at RPCI between 1990 and 1998. Participants were considered physically inactive if they did not participate in any regular, weekly recreational physical activity throughout their lifetime, prior to diagnosis. Multivariate logistic regression models were utilized to estimate odds ratios (OR) and 95% confidence intervals (CI) representing the association between lifetime physical inactivity and HNSCC risk. We observed a significant positive association between recreational physical inactivity and HNSCC risk (OR = 2.73, 95% CI 1.87-3.99, p < 0.001). In subgroup analyses by body mass index (BMI) (underweight/normal-weight: OR = 3.40, 95% CI 1.89-6.12, p < 0.001; overweight/obese: OR = 2.40, 95% CI 1.43-4.02, p < 0.001) and smoking status (former smoker: OR = 3.12, 95% CI 1.89-5.14, p < 0.001; never smoker: OR = 2.71, 95% CI 1.21-6.05, p = 0.020; current smoker: OR = 1.61, 95% CI 0.66-3.95, p = 0.300), significant positive associations were also observed. Results of the current analyses suggest that lifetime physical inactivity associates with HNSCC independent of BMI. In addition, physical inactivity may be a modifiable risk factor among never smokers. These data add to the growing body of evidence suggesting that physical inactivity may be an independent risk factor for cancer.

Impact of Physical Inactivity on Risk of Developing Cancer of the Uterine Cervix: A Case-Control Study.

OBJECTIVE: In this study, we investigated whether physical inactivity was associated with risk of cervical cancer in women treated at an American cancer hospital. METHODS: This case-control study included 128 patients with cervical cancer and 512 controls matched on age. Controls were women suspected of having but not ultimately diagnosed with a neoplasm. Physical inactivity was defined in accordance with the 2008 Physical Activity Guidelines for Americans. Thus, participants reporting, on average, no moderate or vigorous recreational physical activity were classified as inactive. Unconditional logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: Compared with noncancer controls, those with cervical cancer had significantly increased odds of reporting abstinence from recreational physical activity (OR, 2.43; 95% CI, 1.56-3.80). No association was noted between occupational-related physical inactivity and cervical cancer (OR, 0.88; 95% CI, 0.58-1.36). CONCLUSIONS: Our findings suggest that abstinence from regular recreational physical activity is associated with increased odds of cervical cancer. To our knowledge, this is the first US-based study examining these associations. Given the 2008 Physical Activity Guidelines for Americans, this study has identified yet another potential public health benefit to regular physical activity. Further investigation is needed using a larger sample and prospectively collected data to characterize dose of activity to mitigate risk and the optimal window of susceptibility.

Continuous ultrasound-guided adductor canal block for total knee arthroplasty: a randomized, double-blind trial.

BACKGROUND: Adductor canal blocks have shown promise in reducing postoperative pain in total knee arthroplasty patients. No randomized, controlled studies, however, evaluate the opioid-sparing benefits of a continuous 0.2% ropivacaine infusion at the adductor canal. We hypothesized that a continuous adductor canal block would decrease postoperative opioid consumption. METHODS: Eighty subjects presenting for primary unilateral total knee arthroplasty were randomized to receive either a continuous ultrasound-guided adductor canal block with 0.2% ropivacaine or a sham catheter. All subjects received a preoperative single-injection femoral nerve block with spinal anesthesia as is standard of care at our institution. Cumulative IV morphine consumption 48 hours after surgery was evaluated with analysis of covariance, adjusted for baseline characteristics. Secondary outcomes included resting pain scores (numeric rating scale), peak pain scores during physical therapy on postoperative days 1 and 2, quadriceps maximum voluntary isometric contraction, distance ambulated during physical therapy, postoperative nausea and vomiting, and satisfaction with analgesia. RESULTS: Eighty subjects were randomized, and 76 completed the study per-protocol. The least-square mean difference in cumulative morphine consumption over 48 hours (block-sham) was--16.68 mg (95% confidence interval, -29.78 to -3.59, P = 0.013). Total morphine use between 24 and 48 hours (after predicted femoral nerve block resolution) also differed by least-square mean -11.17 mg (95% confidence interval,: -19.93 to -2.42, P = 0.013). Intention-to-treat analysis was similar to the per-protocol results. Functional outcomes revealed subjects in the adductor canal catheter group had better quadriceps strength (P = 0.010) and further distance ambulated (P = 0.034) on postoperative day 2. CONCLUSIONS: A continuous adductor canal block for total knee arthroplasty reduces opioid consumption compared with that of placebo in the first 48 hours after surgery. Other outcomes including quadriceps strength, distance ambulated, and pain scores all show benefit from an adductor canal catheter after total knee arthroplasty but require further study before being interpreted as conclusive.

Animated Videos as a Tool for Teaching Uncommon ENT Diagnoses.

OBJECTIVE: The purpose of this study was to evaluate the knowledge of healthcare professionals and learners regarding the diagnosis and management of nasal septal hematomas (NSH). The secondary objective was to evaluate the effectiveness of a short-form animated video as an educational tool.  Methods: A cross-sectional survey study of healthcare professionals and medical students in the United States was undertaken from October 2022 to June 2023. A pre-test survey was distributed to assess participants' baseline knowledge of NSH management. An educational video on nasal septal hematoma management was presented, followed by a post-test survey to measure the effectiveness of the video.  Results: A total of 142 participant results were collected, 62 (43.7%) of which were attending physicians. There was a significant improvement in knowledge scores across the sample, with a median pre-test score of 83.0% (interquartile range (IQR) 33) and a median post-test score of 100.0% (IQR 17, p<0.001). Additionally, on a visual analog scale (VAS), comfort levels in managing NSH improved from 3.20 to 4.82 (p<0.001) for the entire sample.  Conclusion: NSH is a rare yet potentially devastating otolaryngologic emergency that requires prompt diagnosis and management. A short-form animated video can be an effective tool for educating emergency professionals on diagnosing and managing NSH.

Feeding Issues in Infants Referred for Frenotomy.

INTRODUCTION: The diagnosis of ankyloglossia has increased significantly around the world over the last decade. Frenotomy is indicated in infants with ankyloglossia to improve breastfeeding, although there is little scientific evidence of its efficacy. The purpose of this study is to evaluate whether infants being referred for frenotomy had feeding issues prior to the procedure. METHODS: A retrospective chart review was undertaken for all infants under one year of age referred with ankyloglossia to a pediatric otolaryngology practice or a pediatric hospital between 2018 and 2020. Data included age at referral, gender, comorbidities, feeding issues, whether ankyloglossia was diagnosed, and whether frenotomy was done. Frequencies and non-parametric comparisons were calculated. RESULTS: Of the 646 consultations made for tongue tie, a diagnosis of ankyloglossia was made in 94.7% (N=612) of the patients based on clinical judgment. The most common feeding complaints were poor latch (57.1%, N=369) and painful latch (50.3%, N=325). Eighty one (12.5%) patients did not have a reported feeding difficulty. Most patients had an anterior tongue tie (85.8%, N=554), with some showing signs of restricted tongue movement (30.1%, N=184). Ankyloglossia was 4.03 times more likely to be diagnosed (p<.001) and frenotomy was 1.76 times more likely to be performed (p<.001) in the hospital setting compared to the clinic setting.  Conclusion: Children under the age of one referred to otolaryngology for ankyloglossia were often diagnosed concordantly, although some lacked feeding issues that would indicate frenotomy. There are still knowledge gaps about infantile ankyloglossia in referring medical personnel.

Comparison of Surgical Techniques for the Treatment of Congenital Nasal Pyriform Aperture Stenosis: A Systematic Review.

INTRODUCTION: Congenital nasal pyriform aperture stenosis (CNPAS) is a rare condition that results in neonatal respiratory difficulty. The purpose of this systematic review was to compare surgical outcomes of drilling versus dilation techniques in the treatment of CNPAS. METHODS: Pubmed, Embase, and Cochrane Clinical Trials databases were searched for terms "congenital nasal pyriform aperture stenosis" or "pyriform aperture stenosis" from 2010 to 2021. Twenty-five studies were included that evaluated pediatric patients treated surgically for CNPAS with available outcomes data including complications, revisions, and length of stay. RESULTS: A total of 51 patients with CNPAS were pooled from included studies. The median age was 29 days, 56.9% were female, and 54.9% were born full-term. The median pyriform aperture width before surgery was 5.00 mm (IQR = 4.10, 6.45). Forty (78.4%) patients underwent sublabial drilling, while 6 had a dilation procedure performed with hegar cervical dilators, 2 had a balloon dilation, and 3 were dilated with either an acrylic device, endotracheal tube, or bougie. There were no post-operative complications for 76.5% of patients, while a second surgery was required in 9 (17.6%) patients. The median length of stay was 11 days (IQR = 4, 26). No statistically significant difference was observed between sublabial drilling and surgical dilation techniques with respect to complications, need for revision surgery, or length of stay. CONCLUSION: Current literature is insufficient to determine if drilling or dilation is more effective in the treatment of CNPAS.

Ultrasound-guided adductor canal block for arthroscopic medial meniscectomy: a randomized, double-blind trial.

PURPOSE: The saphenous nerve block using a landmark-based approach has shown promise in reducing postoperative pain in patients undergoing arthroscopic medial meniscectomy. We hypothesized that performing an ultrasound-guided adductor canal saphenous block as part of a multimodal analgesic regimen would result in improved analgesia after arthroscopic medial meniscectomy. METHODS: Fifty patients presenting for ambulatory arthroscopic medial meniscectomy under general anesthesia were prospectively randomized to receive an ultrasound-guided adductor canal block with 0.5% ropivacaine or a sham subcutaneous injection of sterile saline. Our primary outcome was resting pain scores (numerical rating scale; NRS) upon arrival to the postanesthesia care unit (PACU). Secondary outcomes included NRS at six hours, 12 hr, 18 hr, and 24 hr; postoperative nausea; and postoperative opioid consumption. RESULTS: There was a statistically significant difference in mean NRS pain scores upon arrival to the PACU (P = 0.03): block group NRS = 1.71 (95% confidence interval [CI] 0.73 to 2.68) vs sham group NRS = 3.25 (95% CI 2.27 to 4.23). Cumulative opioid consumption (represented in oral morphine equivalents) over 24 hr was 71.8 mg (95% CI 56.5 to 87.2) in the sham group vs 44.9 mg (95% CI 29.5 to 60.2) in the block group (P = 0.016). CONCLUSIONS: An ultrasound-guided block at the adductor canal as part of a combined multimodal analgesic regimen significantly reduces resting pain scores in the PACU following arthroscopic medial meniscectomy. Furthermore, 24-hr postoperative opioid consumption and pain scores were also reduced.

Peritonsillar abscess on NSQIP: Safety of indicated quinsy tonsillectomy.

OBJECTIVE: To compare surgical outcomes for children with peritonsillar abscess (PTA) who are taken to the operating room (OR) for incision and drainage (I&D) or quinsy tonsillectomy. METHODS: This is a multicenter retrospective study of pediatric patients who underwent I&D of a PTA between 2012 and 2017 included in the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database. Patient demographics, comorbidities, and 30-day postoperative events (reoperation, readmission, and complications) were assessed. RESULTS: 777 patients were identified (mean age of 10.7 years, 54% female). 656 (84%) were admitted through the emergency department, and 395 (51%) met criteria for systemic inflammatory response syndrome or sepsis. Fifty-two (6.7%) had a quinsy tonsillectomy done at the time of incision and drainage. For quinsy tonsillectomy versus I&D alone, there was no statistically significant difference in length of stay (LOS) (1.9 v. 1.7 days, p = .523), readmission (17 v. 0, p = .265) or return to the OR (18 v. 1, p = .810). Patients younger than 5 years had a longer LOS (p < .001) while females (p = .003) and patients between 12 and 17 years of age (p = 0.021) were more likely to be readmitted. Of 725 patients treated with I&D alone, 10 (1.4%) patients required a repeat I&D and 6 (0.83%) went on to have an interval quinsy tonsillectomy. CONCLUSIONS: Outcomes of I&D and quinsy tonsillectomy for pediatric PTA in the operating room are the same. If tonsillectomy is indicated in the case of recurrent tonsillitis or PTA, a quinsy tonsillectomy is a good option.

Financial Toxicity for Caregivers of Pediatric Patients With Long-Term Tracheostomies.

OBJECTIVE: To assess financial toxicity experienced by caregivers of children with long-term tracheostomies. METHODS: Cross-sectional survey study with comparison group conducted at a tertiary pediatric hospital and outpatient clinic. Pediatric (<18 years) patients with tracheostomies for ≥12 months were recruited for the study. Patients who underwent tympanostomy tube placement or adenotonsillectomy were recruited as controls. Eligible patients' caregivers were contacted to fill out a questionnaire including the validated Comprehensive Score for Financial Toxicity survey. RESULTS: Surveys were completed for 72 patients, including 31 in the study group (mean age, 6.58 years, 95% confidence interval [CI], 4.85-8.30 years) and 41 controls (mean age, 6.42 years, 95% CI, 5.15-10.52 years) (P = .864). The mean duration of tracheostomy was 3.98 years (95% CI, 2.91-5.05 years). The mean household income and education level were lower in the study group than in the control group. Caregivers of the study group were more likely to have public health insurance or be uninsured. Caregivers of study patients reported greater financial toxicity, with a lower mean Comprehensive Score for Financial Toxicity (18.23 [95% CI, 15.20-21.25]) than caregivers of controls (34.27 [95% CI, 32.05-36.49]; P < .001). Linear regression analysis showed that survey scores were lower for caregivers who employed home nursing care (P < .001). CONCLUSION: Caregivers of pediatric patients requiring long-term tracheostomies experience greater financial toxicity than caregivers of pediatric patients who have typical otolaryngologic surgery.

Patient and Provider Satisfaction With Telemedicine in Otolaryngology.

OBJECTIVE: The objective of this study is to evaluate patient and provider satisfaction with telemedicine encounters across 3 otolaryngology practices. STUDY DESIGN: Cross-sectional survey. SETTING: A military community hospital, an academic military hospital, and a nonmilitary academic center. METHODS: A telephone-based survey of patients undergoing telemedicine encounters for routine otolaryngology appointments was performed between April and July 2020. Patients were asked about their satisfaction, the factors affecting care, and demographic information. A provider survey was emailed to staff otolaryngologists. The survey asked about satisfaction, concerns for reimbursement or liability, encounters best suited for telemedicine, and demographic information. The results were analyzed with descriptive statistics and a multivariable logistic linear regression model to determine odds ratios. RESULTS: A total of 325 patients were surveyed, demonstrating high satisfaction with telemedicine (average score, 4.49 of 5 [best possible answer]). Patients perceived "no negative impact" or "minor negative impact" on the encounter due to the lack of a physical examination or face-to-face interaction (1.86 and 1.95 of 5, respectively). High satisfaction was consistent across groups for distance to travel, age, and reason for referral. A total of 25 providers were surveyed, with an average satisfaction score of 3.44 of 5. Providers reported "slight" to "somewhat" concern about reimbursement (40%) and liability (32%). CONCLUSION: Given patients' and providers' levels of satisfaction, there is likely a role for telemedicine in otolaryngology practice that may benefit patient care independent of the COVID-19 pandemic.

Outcomes of Dog Bite Avulsion Injury Reconstruction With Urinary Bladder Matrix.

Dog bite avulsion injuries of the head and neck are difficult to manage in pediatric patients. This study assesses the outcomes of using porcine urinary bladder extracellular matrix (UBM) for reconstruction of these complete avulsion injuries. Five male pediatric patients underwent reconstruction using UBM. Two (40%) patients underwent reconstruction of the nose; the other 3 patients underwent reconstruction of the forehead, forehead/glabella, and auricle. The average size of the avulsion defect was 7.0 ± 2.4 cm2. No patient developed wound dehiscence, graft loss, or wound infection. Four (80%) patients received pulsed dye laser treatment to improve wound cosmesis. Use of UBM is a safe and effective reconstructive option after dog bite avulsion injuries of the head and neck. Given the advantages of convenient availability and avoidance of donor site morbidity, UBM can be considered for reconstruction of posttraumatic avulsion injuries or Mohs defects.

Using the agile implementation model to reduce central line-associated bloodstream infections.

BACKGROUND: Central line-associated bloodstream infections (CLABSIs) are among the most common hospital-acquired infections and can lead to increased patient morbidity and mortality rates. Implementation of practice guidelines and recommended prevention bundles has historically been suboptimal, suggesting that improvements in implementation methods could further reductions in CLABSI rates. In this article, we describe the agile implementation methodology and present details of how it was successfully used to reduce CLABSI. METHODS: We conducted an observational study of patients with central line catheters at 2 adult tertiary care hospitals in Indianapolis from January 2015 to June 2017. RESULTS: The intervention successfully reduced the CLABSI rate from 1.76 infections per 1,000 central line days to 1.24 (rate ratio = 0.70; P = .011). We also observed reductions in the rates of Clostridium difficile and surgical site infections, whereas catheter-associated urinary tract infections remained stable. CONCLUSIONS: Using the AI model, we were able to successfully implement evidence-based practices to reduce the rate of CLABSIs at our facility.

The association of lifetime physical inactivity with bladder and renal cancer risk: A hospital-based case-control analysis.

OBJECTIVES: Recreational physical inactivity has been gaining recognition as an independent epidemiological exposure of interest in relation to cancer endpoints due to evidence suggesting that it may associate with cancer independent of obesity. In the current analyses, we examined the associations of lifetime recreational physical inactivity with renal and bladder cancer risk. METHODS: In this hospital-based case-control study, we identified N=160 renal cancer patients, N=208 bladder cancer patients, and N=766 age frequency-matched controls without cancer. Participants self-reporting never participating in any regular/weekly recreational physical activity throughout their lifetime were classified as physically inactive. Utilizing unconditional multivariable logistic regression analyses, we estimated odds ratios and 95% confidence intervals to represent the associations between lifetime physical inactivity and renal and bladder cancer risk. RESULTS: In multivariable logistic regression models, we observed significant positive associations between lifetime recreational physical inactivity and renal cancer and bladder cancer risk: odds ratio=1.77 (95% CI: 1.10-2.85) and odds ratio=1.73 (95% CI: 1.13-2.63), respectively. Similar associations also persisted among individuals who were not obese for both renal and bladder cancer: odds ratio=1.75 (95% CI: 1.03-2.98) and odds ratio=1.70 (95% CI: 1.08-2.69), respectively. CONCLUSIONS: In this case-control study, we observed evidence of a positive association between renal and bladder cancer with lifetime recreational physical inactivity. These data add to the growing body of evidence suggesting that physical inactivity may be an important independent risk factor for cancer. However, additional studies using a larger sample and prospectively collected data are needed to substantiate the current findings.

Sex differences in the myocardial inflammatory response to acute injury.

Hemorrhage, trauma, ischemia/reperfusion, burn, and sepsis each lead to cardiac dysfunction. These insults lead to an inflammatory cascade, which plays an important role in this process. Gender has been shown to influence the inflammatory response, as well as outcomes after acute injury. The mechanisms by which gender affects the inflammatory response to and the outcome of acute injury are being actively investigated. We searched PubMed for articles in the English language by using the search words sex, gender, estrogen, testosterone, inflammation, acute injury, ischemia reperfusion, sepsis, trauma, and burns. These were used in various combinations. We read the abstracts of the relevant titles to confirm their relevance, and the full articles were then extracted. References from extracted articles were checked for any additional relevant articles. This review will examine evidence for gender differences in the outcome to acute injury, explain the myocardial inflammatory response to acute injury, and elucidate the various mechanisms by which gender affects the myocardial response to acute injury.

A detailed observation of variations of the facial artery, with emphasis on the superior labial artery.

The reconstruction of lip defects through the use of the Abbe flap and other lip flap procedures involves surgical manipulation of one of the major branches of the facial artery, specifically the superior labial artery (SLA). We examined 284 hemifaces derived from 142 formalin fixed cadavers. Observations regarding the distribution patterns of the facial artery were recognized and categorized into five Types, labeled "A" through "E". Type A (135, 47.5%): facial artery bifurcates into SLA and lateral nasal (the latter gives off inferior and superior alar and ends as angular); Type B (110, 38.7%): similar to Type A, except lateral nasal terminates as superior alar (angular artery is absent); Type C (24, 8.4%): facial artery terminates as SLA; Type D (11, 3.8%): angular artery arises directly from facial arterial trunk rather than as the termination of lateral nasal, with the facial artery ending as superior alar; Type E (4, 1.4%): facial artery terminates as a rudimentary twig without providing any significant branches. Furthermore, we were able to categorize variations within each Type. Sub-Type variations were examined in Types A through C (A: 1-7; B: 1-4; C: 1-3). Our aim was to equip both the anatomist and surgeon with a more thorough understanding of the vasculature of the face, as well as to enable plastic surgeons to have a more confident approach to reconstructive procedures in this region.

Stem cell transplantation as a therapeutic approach to organ failure.

BACKGROUND: Stem cell transplantation is one of the next great frontiers for surgery. Stem cells, which are undifferentiated and self-renewing, have shown the ability to differentiate into cardiomyocytes, as well as many other cell types for potential therapeutic use by surgeons. MATERIALS AND METHODS: As a result, stem cells have the potential to undo irreversible cellular damage, something traditional therapies could not cure. However, numerous issues must be resolved to permit safe and effective clinical application of stem cell therapy. These include the interpretation of cellular labeling, the origin of replicating myocytes, the homing mechanism of stem cells, and the differentiation process. RESULTS: Successful translational research will depend on precise delivery of these cells in real time to the area of interest, e.g., the spinal cord, liver, or heart. Surgeons will be better able to excise and replace/regrow, rather than excise alone. As such, a basic understanding of stem cell biology will benefit the surgeon scientist and clinical surgeon. CONCLUSIONS: The review: 1) discusses myocardial regeneration; 2) defines and categorizes stem cells; 3) presents evidence of stem cell transdifferentiation into cardiomyocytes; and, 4) delineates the therapeutic potential of stem cells in the treatment of ischemic heart disease.

Is the preconditioning threshold different in females?

BACKGROUND: Preconditioning is injury induced protection against subsequent insult. Studies have shown that both males and females may be preconditioned. Females appear to have an innate cardioprotection, therefore, we hypothesized that the preconditioning threshold may differ between males and females. MATERIALS AND METHODS: Male and female rats were divided into five groups (n=4-9). Animals were given an intraperitoneal (i.p.) injection of 125, 250, or 500 micrograms/kilogram Salmonella typhimurium lipopolysaccharide (ETX) or 0.4-ml normal saline (NS). After 24-h incubation another i.p. injection of either 500 micrograms/kilogram ETX (injury dose) or NS was given and the animals incubated an additional 6 h. Shams received two injections of NS. Non-preconditioned rats (PC-) received NS followed by ETX. Preconditioned rats had i.p. injections of 125 mug/kg ETX (PC +125), 250 microg/kg ETX (PC +250), or 500 microg/kg ETX (PC +500) followed by the injury dose ETX. The rats were then anesthetized and myocardial function evaluated with the Langendorff perfusion model. RESULTS: PC +500 females were preconditioned and were able to maintain cardiac function similar to shams. Conversely, PC +125 females were not preconditioned with this stimulus and had a significant decrease in cardiac function similar to PC- rats. Male PC +500 and PC +125 rats, however, retained cardiac function comparable to shams, while PC- males showed a significant decrement. CONCLUSIONS: Males and females may each be preconditioned by endotoxin; however, the preconditioning threshold is higher in females than males.