Inferior vena cava collapsibility loses correlation with internal jugular vein collapsibility during increased thoracic or intra-abdominal pressure.

PURPOSE: Point-of-care ultrasound evaluates inferior vena cava (IVC) and internal jugular vein (IJV) measurements to estimate intravascular volume status. The reliability of the IVC and IJV collapsibility index during increased thoracic or intra-abdominal pressure remains unclear. METHODS: Three phases of sonographic scanning were performed: spontaneous breathing phase, increased thoracic pressure phase via positive pressure ventilation (PPV) phase, and increased intra-abdominal pressure (IAP) phase via laparoscopic insufflation to 15 mmHg. IVC measurements were done at 1-2 cm below the diaphragm and IJV measurements were done at the level of the cricoid cartilage during a complete respiratory cycle. Collapsibility index was calculated by (max diameter - min diameter)/max diameter × 100 %. Chi square, t test, correlation procedure (CORR) and Fisher's exact analyses were completed. RESULTS: A total of 144 scans of the IVC and IJV were completed in 16 patients who underwent laparoscopic surgery. Mean age was 46 ± 15 years, with 75 % female and 69 % African-American. IVC and IJV collapsibility correlated in the setting of spontaneous breathing (r (2) = 0.86, p < 0.01). IVC collapsibility had no correlation with the IJV in the setting of PPV (r (2) = 0.21, p = 0.52) or IAP (r (2) = 0.26, p = 0.42). Maximal IVC diameter was significantly smaller during increased IAP (16.5 mm ± 4.9) compared to spontaneous breathing (20.6 mm ± 4.8, p = 0.04) and PPV (21.8 mm ± 5.6, p = 0.01). CONCLUSION: IJV and IVC collapsibility correlated during spontaneous breathing but there was no statistically significant correlation during increased thoracic or intra-abdominal pressure. Increased intra-abdominal pressure was associated with a significant smaller maximal IVC diameter and cautions the reliability of IVC diameter in clinical settings that are associated with intra-abdominal hypertension or abdominal compartment syndrome.

Lung Injury Prediction Score Is Useful in Predicting Acute Respiratory Distress Syndrome and Mortality in Surgical Critical Care Patients.

Background. Lung injury prediction score (LIPS) is valuable for early recognition of ventilated patients at high risk for developing acute respiratory distress syndrome (ARDS). This study analyzes the value of LIPS in predicting ARDS and mortality among ventilated surgical patients. Methods. IRB approved, prospective observational study including all ventilated patients admitted to the surgical intensive care unit at a single tertiary center over 6 months. ARDS was defined using the Berlin criteria. LIPS were calculated for all patients and analyzed. Logistic regression models evaluated the ability of LIPS to predict development of ARDS and mortality. A receiver operator characteristic (ROC) curve demonstrated the optimal LIPS value to statistically predict development of ARDS. Results. 268 ventilated patients were observed; 141 developed ARDS and 127 did not. The average LIPS for patients who developed ARDS was 8.8 ± 2.8 versus 5.4 ± 2.8 for those who did not (p < 0.001). An ROC area under the curve of 0.79 demonstrates LIPS is statistically powerful for predicting ARDS development. Furthermore, for every 1-unit increase in LIPS, the odds of developing ARDS increase by 1.50 (p < 0.001) and odds of ICU mortality increase by 1.22 (p < 0.001). Conclusion. LIPS is reliable for predicting development of ARDS and predicting mortality in critically ill surgical patients.

Feasibility of common carotid artery point of care ultrasound in cardiac output measurements compared to invasive methods.

BACKGROUND: Cardiac output (CO) measurement in the intensive care unit (ICU) requires invasive devices such as the pulmonary artery (PA) catheter or arterial waveform pulse contour analysis (PCA). This study tests the accuracy and feasibility of point of care ultrasound (POCUS) of the common carotid artery to estimate the CO non-invasively and compare it to existing invasive CO measurement modalities. METHODS: Patients admitted to the surgical and cardiothoracic ICU in a tertiary university-affiliated academic center during a 4-month period, with invasive hemodynamic monitoring devices for management, were included in this cohort study. Common carotid artery POCUS was performed to measure the CO and the results were compared to an invasive device. RESULTS: Intensivists and ICU fellows, using ultrasound of the common carotid artery, obtained the CO measurements. Images of the Doppler flow and volume were obtained at the level of the thyroid gland. Concurrent CO measured via invasive devices was recorded. The patient cohort comprised 36 patients; 52 % were females. The average age was 59 ± 13 years, and 66 % were monitored via PCA device and 33 % via PA catheter. Intraclass correlation coefficient (ICC) analysis demonstrated almost perfect correlation (0.8152) between measurements of CO via ultrasound vs. invasive modalities. The ICC between POCUS and the invasive measurement via PCA was 0.84 and via PA catheter 0.74, showing substantial agreement between the ultrasound and both invasive modalities. CONCLUSIONS: Common carotid artery POCUS offers a non-invasive method of measuring the CO in the critically ill population.

Recovery rate of adrenal function after surgery in patients with acromegaly is higher than in those with non-functioning pituitary tumors: a large single center study.

PURPOSE: To compare hypothalamus-pituitary-adrenal (HPA) axis integrity at diagnosis and recovery after transsphenoidal surgery (TSS), in acromegaly patients, compared with tumor size matched non-functioning adenoma (NFA) patients. METHODS: A retrospective 7-year evaluation of acromegaly patients, who underwent TSS with 52 weeks follow-up at a single institution, was undertaken. 50 acromegaly with complete follow-up data at all points and 50 NFA patients were matched for tumor size; HPA axis was similarly assessed pre-operatively and at 6, 12 and 52 weeks post-operatively. Recovery of HPA axis and gender specific prevalence of adrenal insufficiency (AI), were analyzed in both groups. We also studied AI in acromegaly patients requiring medical therapy post-operatively vs those in remission after surgery. RESULTS: AI remained less prevalent in acromegaly vs NFA (acromegaly, p = 0.01; NFA, p = 0.15) at 52 weeks after surgery, although the prevalence of AI decreased in both groups from baseline by 52 weeks. Additionally, recovery from baseline AI was significantly greater by 52 weeks in acromegaly patients over NFA patients (p = 0.001). Recovery of HPA axis in acromegaly patients remained significant (p = 0.03) despite the need for medical therapy. AI at baseline was proportionately more prevalent in acromegalic males at baseline (p = 0.002) but no gender difference was apparent at 52 weeks (p = 0.35). Conversely, in NFA patients, no gender difference was apparent pre-operatively (p = 0.49), but AI was more prevalent in males at 52 weeks (p = 0.001). CONCLUSION: In the longest comparative study to date using a standard assessment modality, HPA axis recovery was more frequent in acromegaly compared to NFA patients, independent of tumor size, cavernous sinus invasion (CSI), and body mass index (BMI). HPA axis integrity must be carefully and periodically monitored in acromegaly patients during short- and long-term follow-up to prevent overtreatment with glucocorticoids.

Hemodynamic changes in patients undergoing carotid endarterectomy under cervical block and general anesthesia.

BACKGROUND: The objective of this study was to assess differences in hemodynamic stability for patients undergoing carotid endarterectomy (CEA) under general anesthesia (GA) as compared with cervical block anesthesia (CBA). METHODS: An institutional review board-approved, retrospective review of 651 patients from 1998 to 2012 undergoing CEA was performed: 254 patients underwent CEA under CBA and 397 under GA. Comprehensive chart review including preoperative, postoperative, and 30-day follow-up was conducted. Patients were monitored continuously intraoperatively and for 24 hr after surgery. All intraoperative vasoactive and antihypertensive medications administered were recorded. RESULTS: Both groups were similar in age, incidence of coronary artery disease, hypertension, and renal failure. There was a preponderance of female patients, with a high incidence of chronic obstructive pulmonary disease, diabetes mellitus, and nicotine abuse in the GA group. Symptomatic patients predominated the GA group (54% vs. 41%; P = 0.0018). Of the symptomatic patients, 78% experienced transient ischemic attacks in the GA group vs. 64% in the CBA group. Evaluation of hemodynamic stability under GA versus CBA revealed that no significant hemodynamic changes occurred in 34.5% of CBA patients vs. only 14.4% in the GA group. Under GA, incidence of hypotension was 17.84% as compared with 0.52% under CBA (P < 0.001). Under GA, patients had far more hemodynamic fluctuations with 41% of patients demonstrating >3 intraoperative fluctuations in mean arterial pressure of >20% vs. 20% in the CBA group (P < 0.001). Under GA, 51% of patients required vasopressors alone vs. 36% under CBA (P < 0.0002). Antihypertensive medications alone were required in 63% of patients in the GA group vs. 73% in the CBA group (P = 0.0085). Thirty percent of all patients required both vasopressors and antihypertensives during surgery; 23% under CBA vs. 34% under GA (P = 0.0457). There were two postoperative hematoma's CBA cohort. The GA cohort developed postoperative complications (myocardial infarction, 4; stroke, 6; and hematoma, 9), however, these complications were not statistically significant compared with the CBA group. CONCLUSIONS: For patients undergoing CEA, CBA resulted in less hemodynamic fluctuations and fewer intraoperative vasoactive medication requirements as compared with GA.

Racial differences in vasopressor requirements for septic shock.

OBJECTIVE: The objective of this study was to compare vasopressor requirements between African American (AA) patients and white patients in septic shock. METHODS: This was a retrospective cohort review conducted over a 2-year period measuring total and mean dosage of various vasopressors used between two racial groups during the treatment of patients admitted with septic shock. The study included patients admitted to the intensive care unit with septic shock at an 805-bed tertiary, academic center. All septic shock patients were managed with vasopressors. Vasopressor selection, dosage, and duration were at the discretion of the treating physician. Total, mean, and duration of vasopressor dosing requirements were obtained for study participants. Comorbidities, prehospitalization antihypertensive medication requirements, intravenous fluids given during the septic shock phase, and source of infection were analyzed. RESULTS: One hundred fifty-nine patients with septic shock were analyzed, of which 96 (60.4%) were AAs (P < 0.059). African Americans had higher rates of end-stage renal disease and hypertension compared with whites, 85.7% vs. 14.3% (P < 0.011; odds ratio [OR], 15.684) and 68.3% vs. 31.7% (P < 0.007; OR, 3.357), respectively. Norepinephrine (NE) was administered to 150 patients, 57.2% of which were AAs (P < 0.509). Thirteen patients received dopamine (5% AAs, P < 0.588), 40 patients received phenylephrine (15.7% AAs, P < 0.451), and five patients received epinephrine (1.9% AAs, P < 0.660). Comparing vasopressors between races, only NE showed statistical significance via logistic regression modeling for the AA race in terms of total dosage (AAs 736.8 [SD, 897.3] µg vs. whites 370 [SD, 554.2] µg, P < 0.003), duration of vasopressor used (AAs 38.38 [SD, 34.75] h vs. whites 29.09 [SD, 27.11] h, P < 0.037), and mean dosage (AAs 21.08 [SD, 22.23] µg/h vs. whites 12.37 [SD, 13.86] µg/h, P < 0.01). Mortality between groups was not significant. Logistic regression identified discrepancy of the mean dose NE in AAs compared with whites, with OR of 1.043 (P = 0.01). CONCLUSIONS: African American patients with septic shock were treated with higher doses of NE and required longer duration of NE administration compared with white patients.

Normal hypothalamic-pituitary-adrenal axis by high-dose cosyntropin testing in patients with abnormal response to low-dose cosyntropin stimulation: a retrospective review.

OBJECTIVE: To analyze the interpretation of the 1-microg low-dose adrenocorticotropic hormone (ACTH) test (LDT) for assessment of the presence of adrenal insufficiency (AI) in comparison with the 250-microg or standard high-dose ACTH test (HDT), which uses the same cutoff cortisol value of 18 microg/dL (500 nmol/L) as the lower limit of normal. METHODS: We present a retrospective review of 26 patients referred to the Pituitary Clinic who underwent both the LDT and the HDT for evaluation of the function of the hypothalamic-pituitary-adrenal axis. RESULTS: Of the 26 study patients, 23 had discordant findings--abnormal LDT and normal HDT results with use of the empiric cortisol cutoff of 18 microg/dL at 30 minutes in response to the ACTH dose. Glucocorticoid replacement therapy was stopped or not started in these patients, and no clinical symptoms of AI developed during a follow-up period ranging from 19 to 24 months. CONCLUSION: Our retrospective review of patients' discordant LDT and HDT results questions the reliability of the LDT as a screening test for AI, as currently interpreted. Our data suggest that abnormal results should be evaluated in the context of the clinical picture and that additional testing may be indicated to prevent unwarranted treatment with glucocorticoids. Further studies are needed to establish a safe, sensitive, and specific test for the diagnosis of AI.