The hemodynamic and respiratory effects of continuous negative and control-mode cuirass ventilation in recently extubated cardiac surgery patients: Part 2.
OBJECTIVE
Negative-pressure ventilation (NPV) by external cuirass (RTX; Deminax Medical Instruments Limited, London, UK) in intubated patients after cardiac surgery improves hemodynamics measured by pulmonary artery catheter (PAC)-based methods with increased cardiac output (CO) and stroke volume (SV) without changing the heart rate (HR). The less-invasive pressure recording analytical method (PRAM) (MostCare; Vytech Health srl, Padova, Italy) allows radial artery monitoring of CO, SV, SV variation, and cardiac cycle efficiency (CCE). The authors investigated the hypothesis that NPV improves PRAM-based hemodynamics and arterial blood gas analysis in extubated cardiac surgery patients.


METHODS
A clinical investigation.


METHODS
A teaching hospital.


METHODS
Twenty recently extubated cardiac surgery patients.


METHODS
Five consecutive experimental ventilation modalities lasted 5 minutes: (1) baseline (no cuirass ventilation), (2) mode 1 (cuirass ventilation with a continuous negative pressure of -20 cmH(2)O), (3) rest 1 (no cuirass ventilation), (4) mode 2 (cuirass ventilation in the control mode of 12 breaths/min at -20 cmH(2)O, and (5) rest 2.


RESULTS
PRAM parameters were analyzed throughout the final minute of each experimental modality, concluding with arterial blood gas sampling. NPV was well tolerated. HR was unchanged. Mode 2 SV was higher than baseline and rest 2. Mode 2 CO was higher than rest 2. Rest 2 systolic blood pressure was lower than rest 1 and mode 2. Increased CCE with NPV was not significant (p = 0.0696). Oxygenation and PCO(2) were unchanged although mode 2 pH increased.


CONCLUSIONS
Extubated sedated cardiac surgery patients comfortably tolerated NPV with unchanged HR. SV and pH increased.
Department of Cardiac Anaesthesia, Royal Victoria Hospital Belfast, Belfast, UK. williamthomasmcb@doctors.org.uk
William T
WT
McBride
Giulia
G
Ranaldi
Mark J
MJ
Dougherty
Tommaso
T
Siciliano
Brian
B
Trethowan
Peter
P
Elliott
Claire
C
Rice
Sabino
S
Scolletta
Pierpaolo
P
Giomarelli
Salvatore Mario
SM
Romano
David M
DM
Linton
D000368:Aged; D060666:Airway Extubation / Q000379:methods; D001794:Blood Pressure / Q000502:physiology; D006348:Cardiac Surgical Procedures / Q000379:methods; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012121:Respiration, Artificial / Q000379:methods*; D013997:Time Factors; D016896:Treatment Outcome; D015919:Ventilators, Negative-Pressure