Spontaneous Ventilation Versus Pressure Support Ventilation with

Spontaneous Ventilation Versus Pressure Support Ventilation with the
ProSeal LMA in Anaesthetized Pediatric Patients
Kanchi Kamakoti CHILDS Trust Hospital,
Chennai,Tamilnadu, INDIA
Dinesh Kumar Gunasekaran MD, Ramesh Singaravelu MD, Jayanthi Sripathi DA, DNB, Prashanth A Biradar MD
Department of Anesthesiology & Pain medicine, Kanchi Kamakoti CHILDS trust Hospital, Chennai, Tamilnadu, INDIA
METHODS
BACKGROUND
•Anaesthetized children breathing spontaneously tend to fatigue and hypo
ventilate because of the immature muscle fiber type in the diaphragm and
respiratory muscles and the imposed work of breathing due to the airway
device and the breathing circuit.
Table 3 – Group I
•Variables recorded- HR, SpO2, NIBP, RR, ETCO2, level of pressure support
required, trigger, dynamic respiratory compliance, airway resistance, peak and
plateau airway pressure, inhaled and exhaled tidal volume and minute ventilation
HR (bpm)
Spont
•PSV has also been shown to improve gas exchange and reduce work of
breathing when compared to continuous positive pressure ventilation (CPAP)
with PLMA in anaesthetized children.
PSV
OBJECTIVE
-To compare the efficacy of PSV with spontaneous ventilation using a PLMA
in anaesthetized pediatric patients undergoing surgery under combined
general and regional aesthesia.
-To determine the appropriate PSV variables according to age and weight of
pediatric patients.
METHODS
•One hundred ASA I or II patients aged 1 to 12 years scheduled to undergo
day-care surgery below the level of umbilicus under combined general and
regional anesthesia with PLMA were studied
•Exclusion criteria- known or predicted difficult airway, and risk of aspiration
(eg. fasted <4 hours)
•Anesthesia induced with ketamine 1mg/kg and propofol 2-3mg/kg and
appropriate sized PLMA inserted. Feeding tube inserted into drain tube
•Routine monitors were connected (pulse oximeter, ECG, NIBP) and
anesthesia maintained with isoflurane 1% and nitrous oxide 50% in oxygen
•Caudal epidural block or penile block was given using 0.2 % Ropivacaine
•Patients were randomized into either of 2 crossover groups
Group I- underwent spontaneous ventilation followed by PSV of 5min
each
Group II- underwent PSV followed by spontaneous ventilation of 5min
each
PSV was programmed as follows•
•
•
•
•
•
PEEP of 4 cmH2O
The minimum pressure support above PEEP required to
achieve a tidal volume of 10ml/kg Minimum
p
•Patients with airway leaks >15% were excluded from the study
•After the initial 10 min study period, PSV was used in all patients
ETCO2
(mmHg)
Tv (ml)
Mv (L/min)
119.9
29.7
46.2
79.0
2.1
± 18.8
± 10.7
± 3.9
± 25.8
± 0.7
114.1
19.3
39.4
148.7
2.5
± 18.7
± 5.9
± 3.4
± 64.2
± 0.67
0.002
<0.001
<0.001
<0.001
0.001
HR (bpm)
•Statistical analysis was performed using SPSS for windows 16.0
PSV
•A p value of <0.05 was considered statistically significant.
Spont
RESULT
•Six patients were excluded from the study because of excess airway leak ( all
were <10 kgs)
p
RR
(/min)
ETCO2
(mmHg)
Tv (ml)
Mv (L/min)
111.3
18.4
40.4
142.6
2.5
± 14.9
± 2.9
±2.2
± 40.9
± 0.7
117.6
26.0
47.5
83.2
2.1
± 13.2
± 3.5
± 2.6
± 23.2
± 0.8
0.02
<0.001
<0.001
<0.001
<0.001
•No demographic differences between groups
•There was no difference in SPO2 or NIBP during the two modes of ventilation in
both the groups
•Compared to spontaneous ventilation, PSV had lower HR, RR, ETCO2 and higher
tidal volume and minute ventilation
•Measured compliance and resistance were not different between two modes of
ventilation in both groups
•Measurements for spontaneous ventilation in group I were similar to those in
group II
•Measurements for PSV in group I were similar to those in group II
•Psupport showed a negative correlation with age , weight, dynamic compliance
and a positive correlation with airway resistance
Figure 1 – AGE Vs Pressure support , Compliance & Resistance
CONCLUSION
•Our results correlate with A. von Goedecke et al1- CPAP Vs
PSV with PLMA in children- PSV improves gas exchange and
reduces work of breathing
•To achieve a tidal volume of 10ml/kg, a Psupport of
approximately 10cm H2O was required in children >10 kg
which correlates with
A . von Goedecke et al1 and Tokioka
H et al2 who used endotracheal tube and PSV
•Pressure Support Ventilation with a ProSeal LMA, provided
by an anesthesia workstation with a flow triggering is an
effective, safe and easy ventilation mode in anaesthetized
children breathing spontaneously
•Psupport and flow-trigger can be easily set in pediatric
patients.
Table 1- Demographic differences, Table 2 – Relationship between Weight & Psupport range
REFERENCE
Cycling time was set to 20% of the peak inspiratory flow
Respiratory mechanics were recorded using an anesthesia monitoring sidestream spirometer placed between the PLMA and the anesthesia breathing
circuit (Pedi-lite for <10kg and D-lite for >10kg)
(/min)
Table 4- Group II
Flow trigger level to avoid an auto triggering (0.2-0.6L/min)
Apnea time for backup ventilation of 15 sec
RR
GROUP I
n
47
GROUP II
p
Wt (kg)
Pressure Support
Range, Cms H20
47
Age (yrs)
4.23 (± 3.1)
4.24 (±2.7)
0.76
Wt (kg)
15.2 (±1.41)
14.5 (±7.4)
0.12
1. A. von Goedecke et al. Anesth Analg 2005;100:357-60
<10
12.89 (8-14)
2. Tokioka H et al. Anesthesiology 1993;78:880-4
11-19
10.5 (9-12)
For additional information please contact:
9.58 (7-12)
Dinesh Kumar Gunasekaran
Department of Anesthesiology
Kanchi Kamakoti CHILDS Trust Hospital
[email protected]
Pedi-Lite
D-Lite
•The spirometer was connected via a sampling tube to the spirometry module
on the Datex-Ohmeda monitor
M/F (n)
43/4
42/5
0.82
ASA- I/II
45/2
44/3
0.34
(n)
≥20