Anesthetic management of patients with sepsis/septic shock.

Sepsis is defined as life-threatening organ dysfunction caused by a dysregulated host response to infection, while septic shock is a subset of sepsis with persistent hypotension requiring vasopressors to maintain a mean arterial pressure (MAP) of ≥65 mmHg and having a serum lactate level of >2 mmol/L, despite adequate volume resuscitation. Sepsis and septic shock are medical emergencies and time-dependent diseases with a high mortality rate for which early identification, early antibiotic therapy, and early source control are paramount for patient outcomes. The patient may require surgical intervention or an invasive procedure aiming to control the source of infection, and the anesthesiologist has a pivotal role in all phases of patient management. During the preoperative assessment, patients should be aware of all possible organ dysfunctions, and the severity of the disease combined with the patient's physiological reserve should be carefully assessed. All possible efforts should be made to optimize conditions before surgery, especially from a hemodynamic point of view. Anesthetic agents may worsen the hemodynamics of shock patients, and the anesthesiologist must know the properties of each anesthetic agent. All possible efforts should be made to maintain organ perfusion supporting hemodynamics with fluids, vasoactive agents, and inotropes if required.

Changes in Cytokines, Haemodynamics and Microcirculation in Patients with Sepsis/Septic Shock Undergoing Continuous Renal Replacement Therapy and Blood Purification with CytoSorb.

BACKGROUND: Extracorporeal blood purification therapies have been proposed as a strategy to remove inflammatory mediators during sepsis, thus improving outcome. OBJECTIVES: We aimed to evaluate changes in cytokines, haemodynamics and microcirculation during blood purification with Cytosorb adsorber in septic patients. METHODS: Prospective observational study on critically ill adult patients with sepsis/septic shock underwent renal replacement therapy (RRT) for acute renal failure and haemoadsorption with Cytosorb as adjunctive therapy for 24 h. Measurements were taken at baseline, after 6 and 24 h: haemodynamic parameters, arterial and central venous blood gases, plasma levels of tumour necrosis factor alpha, interleukin (IL) 1-beta, IL-6, IL-8 and IL-10. The sublingual microcirculation was assessed with sidestream dark field videomicroscopy to evaluate the perfused vessel density (PVD) and microvascular flow quality. Tissue oxygenation and microvascular reactivity were assessed with thenar near infrared spectroscopy (NIRS) with a vascular occlusion test. RESULTS: Nine patients; plasma levels of IL-8 decreased at 24 h (p < 0.05 versus 6 h); no significant variation was found for other cytokines. Haemodynamic remained stable throughout the observation. Microvascular perfusion improved over time, with an increase in PVDs at 6 and 24 h (from 13.9 [13.3-16.4] to 15.7 [15-17.3] and 17 [14.8-18.6] mm/mm2 respectively, p = 0.003) and total vessel densities at 24 h (14.9 [13.9-16.9] vs. 17.9 [15.3-20], p = 0.0015). No significant variation was detected in NIRS-derived parameters. The Sequential Organ Failure Assessment score decreased from 12 ± 3 to 10 ± 1 at 24 h (p = 0.039). CONCLUSIONS: In septic patients undergoing RRT, haemoadsorption with Cytosorb seems to determine a decreasing in plasma levels of IL-8, although levels of other cytokines did not vary significantly, and an improvement of microcirculation despite no significant variation in macro-haemodynamics.

Thoracic continuous spinal anesthesia for high-risk comorbid older patients undergoing major abdominal surgery: one-year experience of an Italian geriatric hospital.

BACKGROUND: General anesthesia is associated with high morbidity/mortality in comorbid older adults. Thoracic continuous spinal anesthesia/analgesia (TCSA) may be an alternative for major abdominal surgery. We report a one-year experience of the use of TCSA in an Italian geriatric center. METHODS: Retrospective review of case notes of high-risk older patients (ASA class ≥III) who underwent TCSA for major abdominal surgery between May 2017-May 2018. TCSA was performed with a 21-gauge Tuohy-shaped spinal needle and a 24-gauge catheter (level of insertion between T6-7 and T10-11). Hyperbaric bupivacaine or levobupivacaine (two boluses of 2.5 mg) plus fentanyl (10-25 µg) were injected before incision, followed by additional doses if needed. Intrathecal levobupivacaine plus fentanyl were infused for 72 hours after surgery. We described the anesthesiologic management and evaluated the incidence of postoperative complications. RESULTS: Ninety patients (age 84.4±6.9 years, 53.3% male) were enrolled. High comorbidity, according to the Geriatric Index of Comorbidity, was found in 64.4% of the patients. Mean Metabolic Equivalents were 2.58±0.99. Switching to general anesthesia was required in one case. Intraoperative noradrenaline (0.17±0.12 mcg/kg/min) was required in 70.6%. Additional intravenous paracetamol or weak opioids were required in 23% and 2.2% of patients, respectively. No direct complications of TCSA were reported. Cardiac, respiratory and surgical complications occurred in 15.6%, 13.3% and 13.3% of patients, respectively. Delirium occurred in 14.4%. Hospital mortality was 5.6%. CONCLUSIONS: TCSA may be a valid alternative to general anesthesia in high-risk older patients undergoing major abdominal surgery. Further studies are needed to confirm its safety and benefits.

Tissue oxygen saturation changes and postoperative complications in cardiac surgery: a prospective observational study.

BACKGROUND: Cardiac surgery with extracorporeal circulation (ECC) can induce microvascular dysfunction and tissue hypoperfusion. We hypothesized that the alterations in near-infrared spectroscopy (NIRS)-derived parameters would be associated with post-operative complications in cardiac surgery patients. METHODS: Prospective observational study performed at two University Hospitals. Ninety patients undergoing cardiac surgery with ECC were enrolled. The NIRS sensor was applied on the thenar eminence. A vascular occlusion test (VOT, 3-min ischemia) was performed at baseline (t0), at Intensive Care Unit (ICU) admission (t1), 3 (t2) and 6 (t3) hours later. Baseline tissue oxygen saturation (StO2), oxygen extraction rate and microvascular reactivity indices were calculated. RESULTS: In the first hours after cardiac surgery, StO2 tended to increase (86% [80-89] at T3 versus 82% [79-86] at T0, p = ns), while both tissue oxygen extraction and microvascular reactivity tended to decrease, as indicated by increasing occlusion slope (- 8.1%/min [- 11.2 to - 7] at T3 versus - 11.2%/min [- 13.9 to - 7.9] at T0, p = ns) and decreasing recovery slope (1.9%/sec [1.1-2.9] at T3 versus 3.1%/sec [2.3-3.9] at T0, p = ns). No substantial differences were found in NIRS-derived variables and their changes over time between patients with complications and those without complications. CONCLUSIONS: Peripheral tissue oxygen extraction and microvascular reactivity were reduced during the first hours after cardiac surgery. NIRS-derived parameters were not able to predict complications in this population of cardiac surgery patients.

IgM-enriched immunoglobulins (Pentaglobin) may improve the microcirculation in sepsis: a pilot randomized trial.

BACKGROUND: Polyclonal or IgM-enriched immunoglobulins may be beneficial during sepsis as an adjuvant immunomodulatory therapy. We aimed to test whether the infusion of IgM-enriched immunoglobulins improves microvascular perfusion during sepsis. METHODS: Single-centre, randomized, double-blind, placebo-controlled phase II trial including adult patients with a diagnosis of sepsis or septic shock for less than 24 h. Patients received an intravenous infusion of 250 mg/kg (5 mL/kg) per day of IgM-enriched immunoglobulins (Pentaglobin, n = 10) for 72 h or placebo (NaCl 0.9%, n = 9). At baseline and after 24 and 72 h of infusion, the sublingual microcirculation was assessed with Incident Dark Field videomicroscopy. Thenar near-infrared spectroscopy (NIRS) was applied with a vascular occlusion test to assess tissue oxygenation and microvascular reactivity. Levels of interleukin (IL) 1-beta, IL-6, IL-8, IL-10 and tumour necrosis factor alpha were measured in the serum. RESULTS: The perfused vessel density (PVD) for small vessels (diameter < 20 micron) increased in the Pentaglobin group (from 21.7 ± 4.7 to 25.5 ± 5.1 mm/mm2) and decreased in the placebo group (from 25 ± 5.8 to 20.7 ± 4.1 mm/mm2, p for interaction < 0.001, two-way analysis of variance). The absolute between-group difference at 72 h was 4.77 (standard error 2.34), p = 0.140. The microvascular flow index for small vessels increased at 24 h in the Pentaglobin group (from 2.68 [2.38-2.78] to 2.93 [2.82-3], p < 0.01) and decreased at 72 h in the placebo group (from 2.83 [2.60-2.97] to 2.67 [2.48-2.73], p < 0.05). Changes in general parameters, cytokines and NIRS-derived parameters were similar between the two groups, except for IL-6 and IL-10 that significantly decreased at 72 h only in the Pentaglobin group. CONCLUSIONS: A 72-h infusion of IgM-enriched immunoglobulins (Pentaglobin) in patients with sepsis or septic shock may be associated with an increase in sublingual microvascular perfusion. Further studies are needed to confirm our findings. Trial registration NCT02655133, www.ClinicalTrials.gov, date of registration 7th January 2016, https://www.clinicaltrials.gov/ct2/show/NCT02655133.

Changes in the sublingual microcirculation following aortic surgery under balanced or total intravenous anaesthesia: a prospective observational study.

BACKGROUND: In vascular surgery with aortic cross-clamping, ischemia/reperfusion injury induces systemic haemodynamic and microcirculatory disturbances. Different anaesthetic regimens may have a varying impact on tissue perfusion. The aim of this study was to explore changes in microvascular perfusion in patients undergoing elective open abdominal aortic aneurysm repair under balanced or total intravenous anaesthesia. METHODS: Prospective observational study. Patients undergoing elective open infrarenal abdominal aortic aneurysm repair received balanced (desflurane + remifentanil, n = 20) or total intravenous anaesthesia (TIVA, propofol + remifentanil using target-controlled infusion, n = 20) according to the clinician's decision. A goal-directed haemodynamic management was applied in all patients. Measurements were obtained before anaesthesia induction (baseline) and at end-surgery and included haemodynamics, arterial/venous blood gases, sublingual microvascular flow and density (incident dark field illumination imaging), peripheral muscle tissue oxygenation and microcirculatory reactivity (thenar near infrared spectroscopy with a vascular occlusion test). RESULTS: The two groups did not differ for baseline characteristics, mean aortic-clamping time and requirement of vasoactive agents during surgery. Changes in mean arterial pressure, systemic vascular resistance index, haemoglobin and blood lactate levels were similar between the two groups, while the cardiac index increased at end-surgery in patients undergoing balanced anaesthesia. The sublingual microcirculation was globally unaltered in the TIVA group at end-surgery, while patients undergoing balanced anaesthesia showed an increase in the total and perfused small vessel densities (from 16.6 ± 4.2 to 19.1 ± 5.4 mm/mm2, p < 0.05). Changes in microvascular density were negatively correlated with changes in the systemic vascular resistance index. The area of reactive hyperaemia during the VOT increased in the balanced anaesthesia group (from 14.8 ± 8.1 to 25.6 ± 14.8%*min, p < 0.05). At end-surgery, the tissue haemoglobin index in the TIVA group was lower than that in the balanced anaesthesia group. CONCLUSIONS: In patients undergoing elective open abdominal aortic aneurysm repair with a goal-directed hemodynamic management, indices of sublingual or peripheral microvascular perfusion/oxygenation were globally preserved with both balanced anaesthesia and TIVA. Patients undergoing balanced anaesthesia showed microvascular recruitment at end-surgery. TRIAL REGISTRATION: NCT03510793 , https://www.clinicaltrials.gov, date of registration April 27th 2018, retrospectively registered.

Oxygen in the critically ill: friend or foe?

PURPOSE OF REVIEW: To examine the potential harmful effects of hyperoxia and summarize the results of most recent clinical studies evaluating oxygen therapy in critically ill patients. RECENT FINDINGS: Excessive oxygen supplementation may have detrimental pulmonary and systemic effects because of enhanced oxidative stress and inflammation. Hyperoxia-induced lung injury includes altered surfactant protein composition, reduced mucociliary clearance and histological damage, resulting in atelectasis, reduced lung compliance and increased risk of infections. Hyperoxemia causes vasoconstriction, reduction in coronary blood flow and cardiac output and may alter microvascular perfusion. Observational studies showed a close relationship between hyperoxemia and increased mortality in several subsets of critically ill patients. In absence of hypoxemia, the routine use of oxygen therapy in patients with myocardial infarction, stroke, traumatic brain injury, cardiac arrest and sepsis, showed no benefit but rather it seems to be harmful. In patients admitted to intensive care unit, a conservative oxygen therapy aimed to maintain arterial oxygenation within physiological range has been proved to be well tolerated and may improve outcome. SUMMARY: Liberal O2 use and unnecessary hyperoxia may be detrimental in critically ill patients. The current evidence supports the use of a conservative strategy in O2 therapy to avoid patient exposure to unnecessary hyperoxemia.

Effects of short-term hyperoxia on erythropoietin levels and microcirculation in critically Ill patients: a prospective observational pilot study.

BACKGROUND: The normobaric oxygen paradox states that a short exposure to normobaric hyperoxia followed by rapid return to normoxia creates a condition of 'relative hypoxia' which stimulates erythropoietin (EPO) production. Alterations in glutathione and reactive oxygen species (ROS) may be involved in this process. We tested the effects of short-term hyperoxia on EPO levels and the microcirculation in critically ill patients. METHODS: In this prospective, observational study, 20 hemodynamically stable, mechanically ventilated patients with inspired oxygen concentration (FiO2) ≤0.5 and PaO2/FiO2 ≥ 200 mmHg underwent a 2-hour exposure to hyperoxia (FiO2 1.0). A further 20 patients acted as controls. Serum EPO was measured at baseline, 24 h and 48 h. Serum glutathione (antioxidant) and ROS levels were assessed at baseline (t0), after 2 h of hyperoxia (t1) and 2 h after returning to their baseline FiO2 (t2). The microvascular response to hyperoxia was assessed using sublingual sidestream dark field videomicroscopy and thenar near-infrared spectroscopy with a vascular occlusion test. RESULTS: EPO increased within 48 h in patients exposed to hyperoxia from 16.1 [7.4-20.2] to 22.9 [14.1-37.2] IU/L (p = 0.022). Serum ROS transiently increased at t1, and glutathione increased at t2. Early reductions in microvascular density and perfusion were seen during hyperoxia (perfused small vessel density: 85% [95% confidence interval 79-90] of baseline). The response after 2 h of hyperoxia exposure was heterogeneous. Microvascular perfusion/density normalized upon returning to baseline FiO2. CONCLUSIONS: A two-hour exposure to hyperoxia in critically ill patients was associated with a slight increase in EPO levels within 48 h. Adequately controlled studies are needed to confirm the effect of short-term hyperoxia on erythropoiesis. TRIAL REGISTRATION: ClinicalTrials.gov ( www.clinicaltrials.gov ), NCT02481843 , registered 15th June 2015, retrospectively registered.

Exploring alternative routes for oxygen administration.

BACKGROUND: Hypoxemia may compromise cell metabolism and organ function. Supplemental oxygen (O2) at high concentrations may prove ineffective, and issues relating to hyperoxia, barotrauma, mechanical ventilation, and extracorporeal oxygenation are well documented. Old reports suggest the potential safety and efficacy of alternative routes for O2 administration, such as intravenous or intestinal. We re-explored these routes in rat models of hypoxemia. METHODS: Hypoxemia was induced in spontaneously breathing, anesthetized rats by breathing a hypoxic gas mix (FiO2 0.1). Pilot studies infusing pure O2 gas caused early death, likely due to pulmonary embolism. Instead, rats (n = 6/group) were given intravenous O2 via a continuous infusion of pre-oxygenated Hartmann's solution (10 ml/kg/h) for 3 h with normal Ringer's lactate used in control animals. In separate experiments (n = 8/group), bowel intraluminal oxygenation was assessed with pure O2 administered through a cannula placed into the jejunal lumen at a dose of a 15 ml/kg bolus followed by a continuous infusion of 50 ml/kg/h; no treatment was given to controls. Echocardiography, arterial blood gas analysis, mean arterial pressure, muscle and liver tPO2, muscle microvascular perfused vessel density, and urine output were measured. RESULTS: Administration of oxygenated Hartmann's solution (PO2 of solution at end-experiment = 87.5 ± 1.7 kPa) was safe but did not increase either systemic or tissue oxygenation. Similarly, the administration of bowel O2 was safe but did not improve neither systemic nor liver oxygenation. CONCLUSIONS: In this rat model of hypoxemia, the intravenous infusion of gaseous O2 was unfeasible as it induced early mortality. Although safe, both intravenous infusion of oxygenated Hartmann's solution and bowel O2 administration were unable to improve arterial or tissue oxygenation.

Antiangiogenic and antitumor activities of berberine derivative NAX014 compound in a transgenic murine model of HER2/neu-positive mammary carcinoma.

Berberine (BBR) is a natural isoquinoline alkaloid with proven antiangiogenic and anticancer activities. We recently demonstrated that BBR and its synthetic derivative 13-(4-chlorophenylethyl)berberine iodide, NAX014, exert antiproliferative activity against HER2-overexpressing breast cancer cells, inducing apoptosis, modulating the expression of cell cycle checkpoint molecules involved in cell senescence, and reducing both HER2 expression and phosphorylation on tumor cells. In this study, we examined the anticancer properties of BBR and NAX014 in a transgenic mouse model which spontaneously develops HER2-positive mammary tumors. Repeated intraperitoneal injections of a safety dose (2.5mg/kg) of NAX014 delayed the development of tumors, reducing both the number and size of tumor masses. In vivo sidestream dark field videomicroscopy revealed a significant lower vessel density in mammary tumors from NAX014-treated mice in comparison with the control group. Immunohistochemical evaluation using CD34 antibody confirmed the reduced vessel density in NAX014 group. Statistically significant increase of senescence associated ß-galactosidase and p16 expression, and reduced expression of heparanase were observed in tumors from NAX014-treated mice than in tumors from control animals. Finally, NAX014 treatment decreased the level of perforine and granzyme mRNA in mammary tumors. Berberine did not show any statistically significant modulation in comparison with control mice. The results of the present study indicate that NAX014 is more effective than BBR in exerting anticancer activity delaying the development of mammary tumors in mice transgenic for the HER-2/neu oncogene. The antitumor efficacy of NAX014 is mainly related to its effect on tumor vascular network and on induction of tumor cell senescence.

Sidestream dark field videomicroscopy for in vivo evaluation of vascularization and perfusion of mammary tumours in HER2/neu transgenic mice.

Angiogenesis plays a key role in tumour growth and the formation of metastases. Angiogenesis inhibitors and antivascular agents may prove useful in the treatment of breast cancer. A comprehensive characterization of the vasculature and perfusion of mammary tumours is a prerequisite for developing new specific drugs. We used sidestream dark field videomicroscopy to evaluate in vivo the vascular network of spontaneous mammary tumours in HER2/neu transgenic mice. The tumour masses showed higher vessel density compared with the healthy mammary gland (median (interquartile range) total vessel density 16.8 (13.4-20.5) vs 9.1 (8.1-10.9) mm/mm(2), respectively; P < 0.001). Tumor vessel density was reduced in mice treated with the anti-angiogenesis agent berberine, 12.1 (10.6-13.1) mm/mm(2). Sidestream dark field imaging is a versatile technique that may be useful for understanding the role of angiogenesis in the progression of breast cancer and its relationship with outcome. It may represent a valuable tool for dynamic monitoring of the effects of new anti-angiogenesis therapies.