Perioperative Maintenance of Tissue Perfusion and Cardiac Output in Cardiac Surgery Patients

Intraoperative systemic vascular resistance is associated with postoperative nausea and vomiting after laparoscopic hysterectomy

BACKGROUND

The incidence of postoperative nausea and vomiting (PONV) in patients undergoing laparoscopic hysterectomy is very high compared with other surgeries, even when many prophylactic measures have been taken. However, the pathogenesis of PONV is multifactorial. Female sex, a history of motion sickness or PONV, nonsmokers, and perioperative opioid use are the most closely related factors. Among the multiple risk factors, suboptimal gastrointestinal (GI) perfusion may be attributed to some cases of PONV, and increased systemic vascular resistance (SVR) may lead to GI ischemia. The hypothesis of this research was that SVR is related to PONV.

AIM

To investigate the relationship between SVR and PONV in patients undergoing laparoscopic hysterectomy.

METHODS

A total of 228 patients who underwent elective laparoscopic hysterectomy were included in this prospective observational study. SVR was monitored using a noninvasive hemodynamic monitoring system. Four indices of SVR, the baseline, mean, area under the curve (AUC), and weighted AUC, were used for analysis. The incidence and severity of nausea and vomiting were evaluated while patients were awake and throughout the intervals from 0 to 2 h, 2 to 6 h, and 6 to 24 h starting upon arrival at the post-anesthesia care unit. The associations between various SVR indices and PONV were investigated by logistic regression. P < 0.05 was considered statistically significant.

RESULTS

The incidence of PONV in the study was 56.14% (128/228), and PONV tended to appear within 6 h after surgery. Five variables were significant in univariate analyses, however, only SVR mean [odds ratio (OR) = 1.015, 95%CI: 1.005-1.109, P = 0.047] and duration of surgery (OR = 1.316, 95%CI: 1.003-2.030, P = 0.012) were associated with PONV after logistic regression analysis. Furthermore, patients with high SVR mean were more likely to suffer from PONV after laparoscopic hysterectomy. On average, patients who developed PONV needed more time to tolerate diet and demonstrated poorer sleep quality on the first night after surgery.

CONCLUSION

In this study, PONV was a common complication after laparoscopic hysterectomy. SVR was associated with PONV, and high SVR mean was associated with a significantly increased risk of PONV.

The effect of patient positions on perfusion index

Background

The optimal position for surgery is one in which the patient is provided the best possible surgical intervention and put at minimum risk. Different surgical positions may cause changes in tissue perfusion. This study investigates the relationship between surgical patient positions and perfusion index.

Methods

A sample of 61 healthy individuals with no peripheral circulatory disorders, chronic diseases, or anemia was included in this study. Participants held six different positions: supine, prone, 45-degree sitting-supine, 45-degree supine with legs lifted, Trendelenburg (45-degrees head down), and reverse Trendelenburg (45-degrees head up). Perfusion index values were then measured and recorded after individuals held their positions for five minutes.

Results

Participants’ perfusion index values were affected by different body positions (p < 0.05). Perfusion index was lowest in the sitting position (4.5 ± 2.5) and highest in individuals with Trendelenburg position (7.8 ± 3.8).

Conclusion

Different body positions can cause changes in tissue perfusion. This should be considered in patient follow-up along with the perfusion index.

Perfusion indices revisited

Monitoring of tissue perfusion is an essential step in the management of acute circulatory failure. The presence of cellular dysfunction has been a basic component of shock definition even in the absence of hypotension. Monitoring of tissue perfusion includes biomarkers of global tissue perfusion and measures for assessment of perfusion in non-vital organs. The presence of poor tissue perfusion in a shocked patient is usually associated with worse outcome. Persistently impaired perfusion despite adequate resuscitation is also associated with worse outcome. Thus, normalization of some perfusion indices has become one of the resuscitation targets in patients with septic shock. Although the collective evidence shows the clear relation between impaired peripheral perfusion and mortality, the use of different perfusion indices as a resuscitation target needs more research.

Routine postoperative care of patients undergoing coronary artery bypass grafting on cardiopulmonary bypass

The postoperative course of a patient undergoing cardiac surgery (CS) is dictated by a largely predictable set of interactions between disease-specific and therapeutic factors. ICU personnel need to quickly develop a detailed understanding of the patient's current status and how critical care resources can be used to promote further recovery and eventual independence from external support. The goal of this article is to describe a typical operative and postoperative course, with emphasis on the latter, and the diagnostic and therapeutic options necessary for the proper care of these patients. This paper will focus on coronary artery bypass grafting as a model for understanding the course of CS patients; however, many of the principles discussed are applicable to most cardiac surgery patients.

Shock Management for Cardio-surgical Intensive Care Unit Patient: The Silver Days

Shock in cardio-surgical intensive care unit (ICU) patients requires prompt identification of the underlying condition and timely therapeutic interventions. Management during the first 6 hours, also referred to as "the golden hours", is of paramount importance to reverse the shock state and improve the patient's outcome. The authors have previously described a state-of-the-art diagnostic work-up and discussed how to optimise preload, vascular tone, contractility, heart rate and oxygen delivery during this phase. Ideally, shock can be reversed during this initial period. However, some patients might have developed multiple organ dysfunction, which persists beyond the first 6 hours despite the early haemodynamic treatment goals having been accomplished. This period, also referred to as "the silver days", is the focus of this review. The authors discuss how to reduce vasopressor load and how to minimise adrenergic stress by using alternative inotropes, extracorporeal life-support and short acting beta-blockers. The review incorporates data on fluid weaning, safe ventilation, daily interruption of sedation, delirium management and early rehabilitation. It includes practical recommendations in areas where the evidence is scarce or controversial. Although the focus is on cardio-surgery ICU patients, most of the considerations apply to critical ill patients in general.

Shock Management for Cardio-surgical ICU Patients - The Golden Hours

Postoperative shock following cardiac surgery is a serious condition with a high morbidity and mortality. There are four types of shock: cardiogenic, hypovolemic, obstructive and distributive and these can occur alone or in combination. Early identification of the underlying diseases and understanding of the mechanisms at play are key for successful management of shock. Prompt resuscitation measures are necessary to reverse the shock state and avoid permanent organ dysfunction or death. In this review, the authors focus on the management during the first 6 hours of shock (the 'golden hours'). They discuss how to optimise preload, vascular tone, contractility, heart rate and oxygen delivery. The review incorporates the findings of recent trials on early goal-directed therapy and includes practical recommendations in areas in which the evidence is scare or controversial. While the review focuses on cardio-surgical patients, the suggested treatment algorithms might be usefully expanded to other critically ill patients with shock arising from other causes.