36 year old male presents to ED with swelling and discolouration of his foot after stepping on a piece of coral 1 week ago. The patient reports fever and vomiting.

O/E HR 160 BP 120/70 Temp 37 RR 24 Sats 99 FiO2 .4

CPR  >5 seconds, peripherally shut down with mottled skin

Left foot – swollen, grey/blue in colour extending up to groin. Pulses present

ABG

pH 7.30                                              Na 138mmol/l

pCO2 25mmHg                                K 4.0 mmol/l

pO2 156mmHg                                 Cl 102 mmol/l

HCO3 13mmol/l                                Cr 415 umol/l

B/E -11                                               Lactate 9.5 mmol/l

1. Describe and interpret the ABG?

2. What is necrotising fasciitis and how is it managed?