7

Peak ECG:

Interpretation:

Baseline spirometry revealed mild restriction. Spirometry has declined compared from

14/02/2013.

This is submaximal exercise test with reduced exercise tolerance limited by severe dyspnoea and

leg fatigue (Borg of 7 and 8 respectively). Patient achieved a peak work load of 62% and peak VO2

67% predicted and maximum heart rate of 68% predicted. Anaerobic threshold is at the lower

limits of normal (42% predicted VO2 max).

Baseline ECG shows sinus rhythm. No arrhythmias or ischemic changes are observed with exercise

and recovery. No chest pain reported throughout the test. Blood pressure response is normal

(119/85 mmHg at rest increasing to 161/84 at higher stages of exercise). Oxygen pulse is

incrementing normally to increasing workload. Normal heart rate response to increasing workload,

but significant heart rate reserve is noted at the end of exercise

Ventilation is normal during early stage but was hyperventilating during the later stage of exercise.

Tidal volume continues to increase with incremental exercise. No evidence of expiratory and

inspiratory tidal flow limitation with no dynamic hyperinflation noted. Significant breathing reserve

is also noted. Elevated EqCO2 noted in the presence of hyperventilation with no associated oxygen

desaturation.

Conclusion: Submaximal exercise test with reduced exercise tolerance. Hyperventilation was noted

at high workloads with significant breathing reserve. Patient had significant reserve in heart rate at

end of exercise, which might be due to patient's pacemaker. Clinical correlation is recommended

8

Points of Discussion:

Regarding CPET:

It is noted that even at lower levels of exercise and with large breathing reserve, the patient was

only able to increase ventilation predominantly by respiratory rate, with limited tidal volume

expansion. This was potentially due to his restrictive pulmonary fibrosis, or possibly due to his

incompetent left diaphragm which increased the work of breathing. Patient’s VO2/Work Slope was

slightly reduced, indicating a level of deconditioning consistent with his clinical history.

Regarding Cut-off Values for Pre-Operative Assessment:

ACCP guidelines for pre operative assessment for lung cancer (1)

suggest that if both FEV1 and TLCO

>60% predicted it is safe to proceed with surgery with no further testing required. If either or both

FEV1 or TLCO <60% predicted, but are >30% predicted, a low grade exercise assessment such a stair

climb is recommended(1)

.

Where FEV1 and/or TLCO <30% predicted, CPET to measure VO2 max is recommended. Additionally,

patients who walk <400m on a walk test or <22m in a stair climbing test should perform a CPET for

VO2 max. A VO2 max <10ml/min/kg, or <35% predicted should be directed for minimally invasive or

non operative treatment (1)

.

According to ERS/ESTS guidelines (2009), subjects should undertake CPET evaluation if either FEV1 or

TLCO <80% predicted. VO2>20ml/min/kg is considered safe cut off for major resections, up to

pneumonectomy, while VO2 max <10ml/min/kg has a very high risk of post operative death (1)

.

Additional studies have shown that for mixed intra abdominal surgery, a VO2 max <11ml/min/kg (3)

,

upper GI surgery VO2 max <800ml/min/m2 (4)

, bariatric <15.8ml/min/kg are associated with higher

post operative complications(5)

.

Although the VO2 max of 19.4ml/min/kg was borderline according to the above recommendations,

the clinician deemed the patient to be a suitable candidate for diaphragmatic surgery.

Follow up (April 2014):

Patient underwent diaphragmatic hernia repair in April 2014 and has since had no known post

operative complications.

9

References:

1. Colice GL, Shafazand S, Griffin JP, Keenan R, Bolliger CT. Physiological Evaluation of the Patient With Lung

Cancer Being Considered for Resectional Surgery. CHEST 2007; 132(3):161S-177S

2. Brunelli A, Charloux Am Bolliger CT, Rocco G, Sculier JP, Varela G, Licker M, Ferguseon MK, Faivre-Finn C, Huber

RM, Clinic EM, Win T, De Ruysscher D, Goldman L. ERA/ESTS clinical guidelines on fitness for radical therapy in

lung cancer patients (surgery and chemo-radiotherapy). ERJ 2009; 34(1): 17-41

3. Older P, Hall A, Hader R. Cardiopulmonary Exercise Testing as a Screening Test for Perioperative Management of

Major Surgery in the Eldery. CHEST 1999; 116(2): 355-362

4. Hennis PJ, Meale PM, Grocott MPW. Cardiopulmonary Exercise Testing for the Evaluation of Perioperative Risk in

Non-Cardiopulmonary Surgery. PMJ 2011.

5. Trivax JE, Gallagher MJ, Alexander DV, deJong AT, Kasturi G, Sandberg KR, Jafri SM, Krause KR, Chengelis DL, Moy

J, Franklin BA, McCullough PA. Poor Aerobic Fitness Predicts Complications Associated with Bariatric Surgery.

CHEST 2005; 128(4): 282S-283S