Prevention of hypotension during propofol induction: a comparison of preloading with 3.5% polymers of degraded gelatin (Haemaccel) and intravenous ephedrine.

The present study compared the efficacy of preloading with colloid "Haemaccel" with vasoconstrictor (intravenous ephedrine sulphate) in preventing hypotension during propofol induction. This prospective, randomized study included 120 patients of Amercan Society of Anaesthesiologists (ASA) physical status I and II ageing 21 to 50 years of both gender coming for routine surgery. Patients were randomly allocated into three groups with 40 patients in each. Group A (control) did not receive any study medication, group B received Haemaccel (10 ml/kg intravenously over 10-15 minutes) and group C received injection ephedrine (0.2 mg/kg iv) prior to induction of anaesthesia. Propofol (2.5 mg/kg iv) was used for induction of anaesthesia. Heart rate and blood pressure were recorded before induction (baseline) and then every minute for 5 minutes after administering propofol. Anaesthesia was continued with standard technique thereafter. Hypotension was defined as fall in systolic blood pressure more than 20% from the basal value. The incidence of hypotension in Haemaccel (23.1%) or ephedrine group (22.5%) was significantly less than the control group (67.5%, P<0.01). We conclude that though preloading with colloid (Haemaccel) or prior injection of sympathomimetic (ephedrine) are not fully efficacious in preventing hypotension caused by propofol induction, both decrease the incidence in significant number of patients with heart rate less than baseline value in the colloid group.

Breathing comfort associated with different modes of ventilation: a comparative study in non-intubated healthy Nepalese volunteers.

OBJECTIVE: To compare subjective experience of comfort associated with various commonly used supportive modes of mechanical ventilation for weaning in the intensive care unit (ICU). SUBJECTS AND METHODS: The study was carried out in general ICU of a community-based teaching hospital in 30 healthy adult Nepalese volunteers of either sex and 19-37 years of age. The subjects were randomly made to experience breathing via anatomical facemask through ventilator circuit with synchronized intermittent mandatory ventilation (SIMV), assisted spontaneous breathing (ASB), biphasic positive airway pressure (BiPAP), and continuous positive airway pressure (CPAP) modes of ventilation with parameters set at intermediate level of respiratory support. Subjective comfort of breathing was noted using a 10 cm visual analogue scale (VAS) with no discomfort at one end and maximum imaginable discomfort at the other. Inspiratory and expiratory experience of discomfort was also noted using a four point ranking scale (0-no discomfort, 1-mild discomfort, 2-moderate discomfort and 3-severe discomfort). In addition, presence or absence of feeling of breathlessness and inflation was also noted. RESULTS: BiPAP was the most comfortable mode of ventilation (p<0.01) on visual analogue scale. SIMV and CPAP modes were associated with higher discomfort than other modes during inspiratory and expiratory phases respectively. Breathlessness and inflation were least felt in BiPAP and SIMV modes respectively. CONCLUSION: Perception of breathing comfort can vary widely with various supportive modes of ventilation in the ICU. Hence, no single supportive mode should be used in all patients during weaning from mechanical ventilation. Key words: assisted spontaneous breathing; biphasic positive airway pressure; breathing comfort; continuous positive airway pressure; mechanical ventilation; supportive modes synchronized intermittent mandatory ventilation; weaning.