Page 300 Guide to Pain Management in Low-Resource Settings

288 Josephine M. Th orp and Sabu James

that ketamine reduces opioid requirements in surgical In a survey in 2001 in Western Europe, midazolam
intensive care patients. Th e dose range for avoiding psy- was most frequently used for sedation in the inten-
chomimetic side eff ects is 0.2 to 0.5 mg/kg body weight. sive care situation because it has a shorter duration
If using S-ketamine, the dose range has to be divided by of action than diazepam and is less prone to accumu-
two. Long-term use is possible. Ketamine could perhaps lation. Lorazepam is a cost-effective drug that is lon-
be the analgesic of choice in patients with a history of ger acting and can have useful anxiolytic effects for
bronchospasm to have the benefi t of bronchodilator prolonged treatment of anxiety; however, it can result
activity without contributing to arrhythmias, if amino- in oversedation. In the American Society of Critical
phylline is also required. Where expensive analgesics Care Medicine Guidelines, lorazepam was the drug
are not available, ketamine may have a slightly greater recommended for longer-term sedation. Propofol
role as an adjunct in pain relief in intensive care. Also, infusion is also frequently used in many countries
predominantly neuropathic pain might be an indication, in Europe; the advantage being that it can be titrat-
since the “normal” coanalgesics for neuropathic pain, ed easily and the effect will usually diminish quickly
e.g., amitriptyline, carbamazepine, and gabapentin, are once the infusion is stopped, allowing for a “seda-
not available for parenteral use and have a delayed onset tion vacation” in the ICU. In addition to benzodiaz-
of action. epines and propofol, other drugs with sedative prop-
erties have been used in the past and are considered
Can local-anesthetic techniques be used obsolete for sedation: phenothiazines, barbiturates,
in the intensive care unit? and butyrophenones. Opioids should not be used to
Intercostal nerve blocks, paravertebral blocks, epidural achieve sedation, and some of their side effects can be
analgesia, transversus abdominis plane (TAP) blocks, disturbing in themselves.
femoral nerve blocks, and interscalene/brachial plexus Excessive sedation has negative eff ects—re-
blocks can be used as single shots or with catheters duced mobility results in increased risk of deep vein
(not for intercostal blocks) for continuous infusion. To thrombosis and pulmonary thromboembolism. Overse-
avoid nerve damage, nerve stimulators or ultrasound dation may slow the weaning process or delay extuba-
guidance should be used, if the patient is sedated and tion, when the patient is otherwise ready, and so can
paresthesias cannot be communicated. Regular co- prolong ICU stay, with its attendant risks, and increase
agulation profi le, full blood count, and platelet num- the cost of care. After several days of continuous ther-
bers should be noted before these procedures as re- apy with propofol or benzodiazepines, withdrawal phe-
gional techniques are contraindicated in patients with nomena may be precipitated, and reduction in dose
a bleeding tendency such as anticoagulation, coagu- should be gradual to avoid them.
lopathy, and thrombocytopenia. If a continuous tech-
nique with an indwelling catheter is used, this should What adjuncts to pharmacological agents
should be considered in the intensive care unit?
be clearly labeled. A fi lter should be used to minimize
or prevent infections. Th e ICU can be a noisy place with regular monitor
alarms, telephones, and pager calls. Much of the mon-
What to discuss regarding appropriate itor alarm noise is avoidable by setting alarm limits
analgesia for Joe around the expected variables of a particular patient
• Availability of analgesics (both type and form). at that time. Th is means that the alarm will still sound
• Appropriate analgesic for this situation, since this if there is a change beyond the expected. Although pa-
patient has renal failure and coagulopathy. tients may appear asleep or sedated, their hearing may
• Opioids (preferably as a continuous infusion). remain, so discussions about the patient may be bet-
• Nerve block and/or epidural may be appropri- ter held out of earshot as the patient may misinterpret
ate once his renal function improves and he is no limited information. Th is applies perhaps even more
longer coagulopathic. to discussion about other patients, because a listening
patient may mistakenly believe that the conversation
How and when to use anxiolytics and sedatives applies to himself.
Although these drugs have no analgesic proper- Adjustment of the lighting to provide night-
ties, they may reduce the dose of analgesia required. time/daytime levels may help. Even if the patient is