Can peripheral venous pressure be interchangeable with central venous pressure in patients undergoing cardiac surgery?

Objective Pressure measurements at the level of the right atrium are commonly used in clinical anesthesia and the intensive care unit (ICU). There is growing interest in the use of peripheral venous sites for estimating central venous pressure (CVP). This study compared bias, precision, and covariance in simultaneous measurements of CVP and of peripheral venous pressure (PVP) in patients with various hemodynamic conditions.Design and setting Operating room and ICU of a tertiary care university-affiliated hospital.Patients Nineteen elective cardiac surgery patients requiring cardiopulmonary bypass were studied.Interventions A PVP catheter was placed in the antecubital vein and connected to the transducer of the pulmonary artery catheter with a T connector. Data were acquired at different times during cardiac surgery and in the ICU.Measurements and results A total of 188 measurements in 19 patients were obtained under various hemodynamic conditions which included before and after the introduction of mechanical ventilation, following the induction of anesthesia, fluid infusion, application of positive end expiratory pressure and administration of nitroglycerin. PVP and CVP values were correlated and were interchangeable, with a bias of the PVP between –0.72 and 0 mmHg compared to the CVP.Conclusions PVP monitoring can accurately estimate CVP under various conditions encountered in the operating room and in the ICU.This study was supported by the Plan de Pratique des Anesthésiologistes of the Montreal Heart Institute and the Fonds de la Recherche en Santé du Québec.     

Are pressure injuries related to skin failure in critically ill patients?

Background

Pressure injuries contribute significantly to patient morbidity and healthcare costs. Critically ill patients are a high risk group for pressure injury development and may suffer from skin failure secondary to hypoperfusion. The aim of this study was to report hospital acquired pressure injury incidence in intensive care and non-intensive care patients; and assess the clinical characteristics and outcomes of ICU patients reported as having a hospital acquired pressure injury to better understand patient factors associated with their development in comparison to ward patients.

Can changes in arterial pressure be used to detect changes in cardiac index during fluid challenge in patients with septic shock?

Purpose  

Response to fluid challenge is often defined as an increase in cardiac index (CI) of more than 10–15%. However, in clinical practice CI values are often not available. We evaluated whether changes in mean arterial pressure (MAP) correlate with changes in CI after fluid challenge in patients with septic shock.     

Is the sufficiency of discharge instructions related to children's postoperative pain at home after day surgery?

BACKGROUND: Parents are expected to alleviate their children's pain at home after day surgery, and the methods of pain alleviation should be taught to the parents by the hospital staff. However, the lack of information related to children's pain alleviation has been pointed out in several studies. AIM: To describe the relationship between the parent-rated sufficiency of discharge instructions and the postoperative pain behaviours of 1- to 6-year-old children at home after day surgery. METHOD: Questionnaires were handed out to mothers (n = 201) and fathers (n = 114) whose child had undergone minor day surgery in 10 Finnish central hospitals. Percentages and cross-tabulation with chi-square test were used in data analysis. ETHICAL ISSUES: The ethical board in each hospital accepted the study. Parental participation was voluntary. RESULTS: The parents considered the discharge instructions to be fairly sufficient, but criticized their content, method of providing and timing. Insufficiency of the instructions was related to children's postoperative pain behaviours at home. STUDY LIMITATIONS: The fairly low response rate of this study prevents generalization of the findings to all Finnish parents. CONCLUSIONS: Both the content, the methods of providing and the timing of discharge instruction need to be developed in children's day surgery. Special attention should be paid to written instructions, which should be given to the parents prior to the day of the child's surgery. Further research is needed to explore the skills of hospital staff in advising the parents and other factors explaining children's postoperative pain at home.     

Does coagulation differ between elderly and younger patients undergoing cardiac surgery?

OBJECTIVE: Multiple improvements allow cardiac surgery in an increasingly older population. It is still unclear whether perioperative hemostasis differs between elderly and younger patients. DESIGN: Prospective, observational study. SETTING: Single institutional study at an urban, university-affiliated hospital. PATIENTS: Twenty-one consecutive patients aged over 80 years and 21 consecutive patients aged under 60 years undergoing first-time elective aortocoronary bypass grafting. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: Modified thromboelastography (TEG) using different activators [intrinsic TEG (InTEG); extrinsic TEG (ExTEG); fibrinogen TEG (fibTEG)] was carried out to measure coagulation time [CT = reaction time (r)], clot formation time [CFT = coagulation time (k)], and maximum clot firmness [MCF = maximal amplitude (MA)]. Measurements were performed before surgery, at the end and 5 h after surgery on the intensive care unit (ICU), and on the morning of the 1st postoperative day (POD). Blood loss was slightly higher in the elderly than in the younger patients. Most TEG data were already significantly different between elderly and younger patients at baseline, indicating altered coagulation in the elderly prior to surgery (hypocoagulability). After surgery and on the ICU, elderly patients showed similar alterations in TEG to those of the younger patients (e.g. InTEG-CT: from 183+/-21 to 239+/-28 s versus from 146+/-15 to 186+/-26 s). On the 1st POD, most TEG data had returned almost to baseline values, however, they were still different between elderly and younger patients. CONCLUSIONS: Elderly cardiac surgery patients already showed moderately altered coagulation prior to surgery. Thus elderly patients may be at risk of developing postoperative alterations in hemostasis on the ICU. The exact reasons for the impaired coagulation in the elderly remains to be determined.     

Does platelet size correlate with function in patients undergoing cardiac surgery?

Objective Platelet dysfunction secondary to cardiopulmonary bypass (CPB) is one of the major reasons for nonsurgical post-operative bleeding in cardiac surgery. Whether platelet size is an indicator for platelet function was investigated in patients undergoing coronary artery bypass grafting.Design Prospective study.Setting Intra-operative, cardiac surgery operations.Patients 80 consecutive patients undergoing coronary artery bypass grafting. Excluding criteria were pre-operative coagulation disorders and medication with anticoagulants within the last 10 days before the operation day.Measurements and results Platelet function was assessed by aggregometry using a turbidimetric method (inductors: ADP 2.0 mol/l, collagen 4 g/l, epinephrine 25 mol/l). Mean platelet volume (MPV) was measured by an electrical conductivity method. Measurements were carried out before, during, and after CPB until the 1st post-operative day on intensive care unit (ICU). Platelet size decreased significantly during CPB (max. –25% after weaning from bypass) and returned to baseline values on the 1st post-operative day. Platelet count (ranging from 93–304×10⁹/l) did not correlate significantly with MPV or aggregation variables. Maximum aggregation and maximum gradient of aggregation induced by ADP and collagen were significantly decreased by CPB with the most pronounced reduction at the end of CPB (ranging from –25% to –45%). Analyses of co-variance revealed a significant correlation between changes in MPV and changes in aggregation variables (ADP, collagen).Conclusion Platelet volume is easy to measure even in the operation room or in ICU and may indicate abnormalities in platelet function in the post-bypass period of cardiac surgery patients.     

Laparoscopic cholecystectomy in cardiac transplant patients - lower threshold for surgery?

Summary

Laparoscopic cholecystectomy is accepted by the surgical community as an advance in the definitive treatment of gallstones. In this paper we describe five patients post-cardiac transplantation, in whom laparoscopic cholecystectomy was undertaken. One patient, who had two previous laparo-tomies, required conversion to an open cholecystectomy. In each case the gallstones were symptomatic and were a major cause of morbidity. The average hospital stay was 4 days in uncomplicated cases, but was prolonged in one patient who required stabilization of cyclosporin levels (7 days) and in one patient due to a sub-hepatic collection (17 days). This was successfully treated by percutaneous ultrasound guided drainage. The technical problems of laparoscopic cholecystectomy are no different in transplant patients but it may have the advantage of being less immunotraumatic and allow earlier mobilization. Laparoscopic cholecystectomy is an advance in the treatment of gallstones and because of the risks of acute cholecystitis in cardiac transplant patients, should lower the threshold to definitive surgery.     

Abdominal compartment syndrome: does intra-cystic pressure reflect actual intra-abdominal pressure? A prospective study in surgical patients

Background  

Abdominal compartment syndrome is defined as the adverse physiologic effects of increased intra-abdominal pressure. Prolonged, unrelieved pressure may lead to respiratory compromise, renal impairment, cardiac failure, shock, and death. Abdominal compartment syndrome is diagnosed by measuring intra-cystic pressure as a reflection of intra-abdominal pressure. To examine the validity of the technique, we conducted a prospective study in surgical patients by directly measuring bladder and abdominal pressures simultaneously during laparoscopic cholecystectomy using a previously described technique.     

Is there a difference between women and men in characteristics and outcome after in hospital cardiac arrest?

AIM: To describe the characteristics and outcome among patients suffering from an in-hospital cardiac arrest in women and men. METHODS: All patients who suffered an in-hospital cardiac arrest during a 4 year period in Sahlgrenska Hospital G?teborg, Sweden, where the cardiopulmonary resuscitation (CPR) team was called, were recorded and described prospectively in terms of characteristics and outcome. RESULTS: There were 557 patients suffering in-hospital cardiac arrest in whom the CPR-team was alerted. Among them, 217 (39%) were women. Women differed from men having a lower prevalence of earlier myocardial infarction, angina pectoris, renal disease and a higher prevalence of rheumatic disease. In terms of aetiology of the cardiac arrest, 47% men and 48% women were judged to have had a confirmed or possible AMI. More men than women were found in ventricular fibrillation/ventricular tachycardia (VF/VT) (57 vs. 41%; P<0.001), whereas more women were found in pulseless electrical activity (30 vs. 15%; P<0.0001). Cerebral performance categories (CPC)-score at discharge did not differ between men and women. Among women, 36.4% survived to discharge as compared with 38.0% among men (NS). Survival from VF/VT was 64.3% in women and 52.7% in men (NS). When correcting for dissimilarities at baseline, the adjusted odd ratio for being discharged alive from hospital among women as compared with men was 1.66 (95% confidence limit 1.06-2.62; P=0.028). CONCLUSION: Thirty nine percent of patients suffering in-hospital cardiac arrest for whom the CPR-team was alerted, were women. Women were less frequently found in VF/VT than men. After correcting for dissimilarities at baseline, female gender was associated with a small improvement in survival.     

In-hospital cardiac arrest: Is outcome related to the time of arrest?

BACKGROUND: Whether outcome from in-hospital cardiopulmonary resuscitation (CPR) is poorer when it occurs during the night remains controversial. This study examined the relationship between CPR during the various hospital shifts and survival to discharge. METHODS: CPR attempts occurring in a tertiary hospital with a dedicated, certified resuscitation team were recorded prospectively (Utstein template guidelines) over 24 months. Medical records and patient characteristics were retrieved from patient admission files. RESULTS: Included were 174 in-hospital cardiac arrests; 43%, 32% and 25% in morning evening and night shifts, respectively. Shift populations were comparable in demographic and treatment related variables. Asystole (p < 0.01) and unwitnessed arrests (p = 0.05) were more common during the night. Survival to discharge was poorer following night shift CPR than following morning and evening shift CPR (p = 0.04). When asystole (being synonymous with death) was excluded from the analysis, the odds of survival to discharge was not higher for witnessed compared to unwitnessed arrest but was 4.9 times higher if the cardiac arrest did not occur during the night shift (p = 0.05, logistic regression). The relative risk of eventual in-hospital death for patients with return of spontaneous circulation (ROSC) following night shift resuscitation was 1.9 that of those with ROSC following morning or evening resuscitation (Cox regression). CONCLUSIONS: Although unwitnessed arrest is more prevalent during night shift, resuscitation during this shift is associated with poorer outcomes independently of witnessed status. Further research is required into the causes for the increased mortality observed after night shift resuscitation.     

Is there a change in myocardial nonlinearity during the cardiac cycle?

The distortion of a sound wave during propagation results in progressive transfer of the energy from fundamental to higher harmonics, and is dependent on the nonlinearity of the medium. We studied if relative changes in acoustical nonlinearity occur in healthy myocardium during the cardiac cycle. Radiofrequency data were acquired from transthoracic echocardiography (2.5 and 3.5 MHz), parasternal long axis view, from five dogs and nine healthy volunteers. Integrated backscatter was calculated after filtering for fundamental (FIB) and second harmonic frequencies (SHIB), from a region in the posterior myocardial wall. The results suggest that there is little difference between the SHIB and FIB, although there were large variations between individuals. The maximal changes in nonlinearity, as estimated by SHIB/FIB ratio, mostly occurred during systole. SHIB presented similar cyclic variation with FIB (p = NS). Further studies are necessary to separate the role of myocardial nonlinearity, attenuation, propagating distance, or acoustical properties of the blood. The results are important in further tissue characterization studies employing second harmonic data.