Peri-mortem and ante-mortem haemodynamic profile of severe sepsis/septic shock

Objective

To describe the main haemodynamic parameters obtained in patients with severe sepsis and septic shock, who died several hours later.

Design

A prospective, observational study, using transthoracic echocardiography.

Setting

A medical/surgical 14-bed ICU.

Materials and methods

In the patients enrolled the following echocardiographic parameters were obtained: left ventricular (LV) telediastolic dimension, left ventricular shortening fraction (LVSF), cardiac output (CO), by determination of the flow velocity integral of the LV out-flow tract using pulsed-wave Doppler analysis, and the determination of the inferior vena cava (IVC) maximal and minimum dimensions, and the IVC index (maximum dimension - minimum dimension × 100/maximum dimension). A CO between 2.4 l/min/m² and 4 l/min/m² was considered normal, as well as a LVSF of 36 ± 6%. Based on the characteristics of CO and the IVC index, we considered the following types of shock and/or hypotension: cardiogenic (low CO and IVC index < 25%), vasogenic (normal or high CO and variable IVC index), and hypovolemic (low CO and IVC index > 50%).

Twenty-seven patients were enrolled, and divided into two groups: group 1 consisted of patients with a haemodynamic evaluation up to 6 hours before death (peri-mortem group, n = 14), and group 2 with a haemodynamic evaluation between 6 and 12 hours before death (ante-mortem group, n = 13). In all patients was determined: age, sex, arterial pressure, heart rate, APACHE II score, SAPS II, SOFA, MODS, serum lactate, and central venous pressure (CVP).

Results

Six patients in group 1 and three patients in group 2 presented a situation compatible with a cardiogenic type of hypotension. The remainder presented as a vasogenic type of hypotension. Eight patients in group 1 presented LVSF < 30%, as well as four patients in group 2 All severity scores of group 1 were slightly higher, as well as serum lactate levels. The main results are presented in Table 1, with means and standard deviation for each variable.

Table 1

Conclusions

Septic shock presents as a vasogenic type until the late disease course. A LV failure with a cardiogenic type of situation characterizes better the later stages, up to 6 hours before death occurs.