Goal-directed therapy of cardiac preload in induced whole-body hyperthermia

Anesthetic management of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy procedures

Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy procedure are performed with increasing frequency to treat patients with diffused peritoneal carcinomatosis. These procedures have showed to increase life expectancy in what was previously considered a “terminal condition”. Anyway patients face major and life threatening derangements of their hemodynamic, respiratory and metabolic physiologic balance during the surgery and in the immediate postoperative period. Despite the need of an advanced organ monitoring and support all these derangements seem to be mild and short-lived when timely addressed, at least in the majority of patients. Intensive care physicians are involved in providing surveillance and organ support till the patient is effectively weaned after the operation. Moreover, the anesthesiologist as perioperative physician is involved in pain control, metabolic and nutritional support of this cohort of patients. This task can be challenging considering that part of the patients are already on a long list of pain control medication after previous surgery or chemotherapy. A malnourished state is common too and it is secondary to difficult feeding, wasting syndrome from the tumor and massive ascites. The last issue the anesthesiologists need to be aware of is the impact over the quality of life (QoL) of this procedure. The patient’s underlying pathology is unlikely to be definitively cured so no treatment is an acceptable choice. The possibility to withhold the treatments must be part of the consultation process like the discussion about the QoL in the immediate, as well as in the long-term, after the operation. Careful monitoring and treatment of every aspect that can impact the QoL must be taken and the efforts to be poured into an effective preservation of the QoL must be doubled when compared with a patient scheduled for major abdominal surgery.

Comparison of values in critically ill patients for global end-diastolic volume and extravascular lung water measured by transcardiopulmonary thermodilution: a meta-analysis of the literature

INTRODUCTION

Hemodynamic parameters such as the global end-diastolic volume index (GEDVI) and extravascular lung water index (EVLWI), derived by transpulmonary thermodilution, have gained increasing interest for guiding fluid therapy in critically ill patients. The proposed normal values (680-800ml/m(2) for GEDVI and 3-7ml/kg for EVLWI) are based on measurements in healthy individuals and on expert opinion, and are assumed to be suitable for all patients. We analyzed the published data for GEDVI and EVLWI, and investigated the differences between a cohort of septic patients (SEP) and patients undergoing major surgery (SURG), respectively.

METHODS

A PubMed literature search for GEDVI, EVLWI or transcardiopulmonary single/double indicator thermodilution was carried out, covering the period from 1990 to 2010.

INTERVENTION

Meta-regression analysis was performed to identify any differences between the surgical (SURG) and non-surgical septic groups (SEP).

RESULTS

Data from 1925 patients corresponding to 64 studies were included. On comparing both groups, mean GEDVI was significantly higher by 94ml/m(2) (95%CI: [54; 134]) in SEP compared to SURG patients (788ml/m(2) 95%CI: [762; 816], vs. 694ml/m(2), 95%CI: [678; 711], p<0.001). Mean EVLWI also differed significantly by 3.3ml/kg (95%CI: [1.4; 5.2], SURG 7.2ml/kg, 95%CI: [6.9; 7.6] vs. SEP 11.0ml/kg, 95%CI: [9.1; 13.0], p=0.001).

CONCLUSIONS

The published data for GEDVI and EVLWI are heterogeneous, particularly in critically ill patients, and often exceed the proposed normal values derived from healthy individuals. In the group of septic patients, GEDVI and EVLWI were significantly higher than in the group of patients undergoing major surgery. This points to the need for defining different therapeutic targets for different patient populations.

Whole Body Hyperthermia by Extracorporeal Circulation in Spontaneously Breathing Sarcoma Patients: Hemodynamics and Oxygen Metabolism

Purpose

This phase I study was performed to evaluate the feasibility and toxicity of a new method of extracorporeal perfusion-induced whole body hyperthermia (WBHT) in patients with advanced sarcoma avoiding the need of intubation and general anesthesia.

Methods

One double-lumen femoral venous access was inserted by Seldinger's technique to obtain WBHT (41.8°C for 120 minutes) via an extracorporeal circuit. No concomitant chemotherapy was applied. Up to 4 treatments of WBHT were performed under moderate sedation in 6 spontaneously breathing patients. Invasive hemodynamic monitoring was performed by use of a pulmonary artery catheter.

Results

After their first WBHT session, 2 patients were excluded from further treatment due to transient liver toxicity or catheter-related complication, so a total of 12 cycles remained for analyses. In all patients, conscious sedation resulted in sufficient spontaneous respiration without the need for mandatory ventilation. Median time to reach the target temperature was 84 minutes (range 60–142). Hemodynamic changes revealed the expected hyperdynamic state: heart rate, cardiac index, and stroke volume index significantly increased (p<0.05), whereas blood pressure and systemic and pulmonary vascular resistance index significantly decreased (p<0.05). A net fluid balance of 5822+1766 mL as well as norepinephrine (mean; 0.062 μg·kg1·min−1) were necessary to maintain the mean arterial blood pressure >60 mmHg.

Conclusion

Our data demonstrate the feasibility of this method of extracorporeal WBHT without mandatory ventilation. Hemodynamic side effects in spontaneously breathing patients during perfusion-induced WBHT seem less severe than those observed in radiant heat WBHT.

Changes in hepatic blood flow during whole body hyperthermia

PURPOSE

Changes in blood flow distribution are important for heat dispersion and for supportive therapeutic strategies such as simultaneous whole body hyperthermia (WBH) and administration of chemotherapy. The aim of this clinical study was to determine changes in hepatic blood flow during WBH for the treatment of metastatic cancer.

MATERIALS AND METHODS

This observational clinical study was part of a phase I/II feasibility study of WBH. WBH was induced using a radiant heat device. Hepatic blood flow was estimated using indocyanine green clearance measurements. The plasma disappearance rate of indocyanine green (PDR-ICG) was recorded in percent/min. We used an invasive thermo-dye-dilution technique to estimate hepatic blood flow, cardiac output, and volume status. Mean arterial blood pressure was also measured invasively. To determine the effects of hyperthermia the measurements were performed at defined temperature points.

RESULTS

In 10 of 22 treatments the PDR-ICG fell below normal values during hyperthermia, which represented a significant fall in hepatic blood flow. Cardiac output, volume status, and mean arterial blood pressure did not differ between patients whose liver blood flow was reduced and those whose liver blood flow remained unchanged.

CONCLUSIONS

We observed distinct reductions in hepatic blood flow during WBH, which suggested a significant redistribution of blood flow away from the core during WBH. This was not mirrored by global circulatory parameters.

How to measure and interpret volumetric measures of preload

PURPOSE OF REVIEW

To update the situation over the past few years on the clinical application of volumetric measures of preload in critically ill patients.

RECENT FINDINGS

Cardiac filling pressures monitoring is unreliable for assessing cardiac preload in mechanically ventilated critically ill patients. The transpulmonary dilution indicator technique was shown to better identify preload than pulmonary arterial catheterization. Measuring static preload index as intrathoracic blood volume or global end diastolic volume provides a good preload index, either in experimental or in different clinical settings.

SUMMARY

Volumetric measures of preload are good preload indexes. These data are to be interpreted together with the clinical patient's condition, conventional hemodynamic data and the course of illness in critically ill patients. In order to evaluate whether the application of a predefined therapy algorithm based on volumetric monitoring can improve patients' outcome, more studies are needed.

Genomic profile of matrix and vasculature remodeling in TGF-alpha induced pulmonary fibrosis

Expression of transforming growth factor alpha (TGF-alpha) in the respiratory epithelium of transgenic mice caused pulmonary fibrosis, cachexia, pulmonary hypertension, and altered lung function. To identify genes and molecular pathways mediating lung remodeling, mRNA microarray analysis was performed at multiple times after TGF-alpha expression and revealed changes consistent with a role for TGF-alpha in the regulation of extracellular matrix and vasculogenesis. Transcripts for extracellular matrix proteins were augmented along with transcripts for genes previously identified to have roles in pulmonary fibrosis, including tenascin C, osteopontin, and serine (or cysteine) peptidase inhibitor, clade F, member 1. Transcripts regulating vascular processes including endothelin receptor type B, endothelial-specific receptor tyrosine kinase, and caveolin, caveolae protein 1 were decreased. When TGF-alpha expression was no longer induced, lung remodeling partially reversed and lung function and pulmonary hypertension normalized. Transcripts increased during resolution included midkine, matrix metalloproteinase 2, and hemolytic complement. Hierarchical clustering revealed that genes regulated by TGF-alpha were similar to those altered in the lungs of patients with idiopathic pulmonary fibrosis. These studies support a role for epithelial cell-derived TGF-alpha in the regulation of processes that alter the airway and vascular architecture and function.