Peri-operative Medication Dosing in Adult Obese Elective
Surgical Patients: A Systematic Review of Clinical Studies
Syed Tabish Razi Zaidi
Ó Springer International Publishing AG, part of Springer Nature 2018
Background Despite the increasing numbers of obese
patients undergoing elective surgery, there is a lack of
evidence-based dosing guidelines for peri-operative medi-
cations in obesity.
Objective The objective was to systematically review the
dosing and outcomes of peri-operative medications used in
obese elective surgical patients.
Methods Medical subject headings and general keywords
were used to systematically search multiple databases
(PubMed, EMBASE, Cochrane Library and CINAHL). Studies
of medications in obese surgical patients were included if they
had a non-obese control or comparative dosing scalar group.
The National Health and Medical Research Council GRADE
tool was used to assess quality of evidence for each drug.
Results Thirty-three studies of six drug classes were identiﬁed:
anaesthetics (n = 6), muscle relaxants (n = 10), neuromuscular
reversal agents (n = 3), analgesics (n = 2), antibiotics (n =5)
and anticoagulants (n = 7). A variety of dose scalars and/or
recommendations was observed for various medications. Lean
body weight was proposed as a suitable weight scalar for
induction of anaesthesia with propofol whereas total body
weight for maintenance of anaesthesia with propofol and
depolarizing muscle relaxants. Ideal body weight was reported
as an appropriate dosing scalar for non-depolarizing muscle
relaxants and neuromuscular reversal agents. Both corrected
body weight 40% and ideal body weight were reported as
suitable weight scalars for post-operative analgesia with mor-
phine. The standard 2-g dose of cefazolin appeared effective in
the prevention of surgical site infection. Body mass index
stratiﬁed dosing of enoxaparin was effective for venous
Conclusion No drug recommendation achieved an ‘‘Ex-
cellent’’ quality of evidence. Limited data suggest that
clinicians should consider each individual class of medi-
cation when selecting a dose for obese surgical patients.
Routine use of ﬁxed-dosing regimens is likely to under- or
overdose obese patients thus predisposing them to adverse
drug events or treatment failure leading to patient harm.
No peri-operative drug recommendation achieved an
‘‘Excellent’’ quality of evidence for dosing in obese
Limited data suggest that clinicians should consider
each individual class of medication when selecting a
dose for obese surgical patients.
Routine use of ﬁxed dosing regimens is likely to
under- or overdose obese patients thus predisposing
them to adverse drug events or treatment failure
leading to patient harm.
Electronic supplementary material The online version of this
article (https://doi.org/10.1007/s40261-018-0662-0) contains supple-
mentary material, which is available to authorized users.
& Syed Tabish Razi Zaidi
Division of Pharmacy, School of Medicine, Faculty of
Health, University of Tasmania, Pharmacy Building, Dobson
Road, Private Bag 26, Hobart, TAS 7001, Australia
Clin Drug Investig