Types of sutures (and when to use them)


There are many types of sutures and they differ by size, material and needle. I made this handy chart to help remember how long each type of material lasts in the body and what it’s commonly used for:

50% Strength Gone Reactivity Use
(coated polyethylene)
indef n/an/a + Tendon
(uncoated polyethylene)
indef n/a + Tendon
Nylon 20%/y n/a + Skin
Silk 1 year >2y ++++ Vessel ligation, drains
indef n/a Skin
Steel indef n/a Tendon, sternum
Fast Gut 6d 20d ++++ Skin
Plain Gut 7d 70d ++++ Skin
Chromic Gut 28d 90d ++++ Oral mucosa
(Poliglecaprone 25)
7d 110d +++ Skin, subcuticular
21d 100d ++ Internal organs, fascia
(Polyglactin 910)
21d 90d ++ Skin, soft tissue

* Monofilament
* Braided

TNM Staging for Prostate Cancer

TNM Prostate Cancer Staging


    • Tx: primary tumor cannot be assessed
    • T0: no evidence of a primary tumor
    • T1: clinically in apparent tumor neither palpable not visible by imaging
      • T1a: incidental histology – <5% of resected tissue
      • T1b: incidental histology – >5% of resected tissue
      • T1c: increased PSA and subsequent identification by needle biopsy
    • T2: tumor confined within prostate
      • T2a: half of one lobe or less
      • T2b: greater than half of one lobe, none in other
      • T2c: both lobes
    • T3: tumor extends through capsule
      • T3a: extracapsular extravasion
      • T3b: tumor invades seminal vesicles
    • T4: tumor is fixed or invades adjacent structures other than the seminal vesicles (external sphincter, rectum, bladder, lavator muscles, and/or pelvic wall).


  • Nx: regional lymph nodes not assessed
  • N0: no lymph node metastasis
  • N1: metastasis in regional node(s)


  • M0: no distant metastasis
  • M1a: non-regional lymph node(s)
  • M1b: bone(s)
  • M1c: other sites with or without bone disease
    • When more than 1 site of metastasis is present give advanced stage (M1c) is given

Storage vs voiding symptoms of prostatism

Prostatism – urinary symptoms caused by the prostate

**IMPORTANT prostatism symptoms are not necessarily caused by an “enlarged” prostate because it’s not the absolute size of the prostate that causes symptoms, it’s how much the prostate is interfering with the flow of urine.

Useful to divide symptoms into storage and voiding.


  • Frequency
  • Urgency
  • Nocturia


  • Hesitancy
  • Poor flow
  • Intermittent flow
  • Straining
  • Incomplete emptying

Symptoms can be graded using the International Prostate Symptom Score (IPSS) which rates emptying, frequency, intermittency, urgency, weak stream, straining, and nocturia on scales of 0 – 5. You then add the scores together to get a score out of 35.
0-7 Mildly symptomatic
8-19 Moderately symptomatic
20-35 Severely symptomatic

Stress, urge, overflow and mixed incontinence

Urinary incontinence is going when you don’t want to go. It is a big deal because socially it’s just not acceptable and can lead to a lot of psychological stress. If you can’t remember the stages of voiding or the neural control, click here for a refresher.

Types of urinary incontinence

  • Stress: it is caused by an increase in intraabdominal pressure (laughing, coughing, sneezing) and a sphincter that can’t contract enough to prevent leakage
    • Most common type of incontinence in young women
  • Urge: uninhibited contractions of the detrusor muscle, common in older individuals
    • Common in older individuals
  • Mixed: most common type of incontinence, usually refers to a mix of urge and stress incontinence
    • Most common in general
  • Overflow: when the bladder is so full it cannot hold in the urine
    • Common when there’s an obstruction or spinal cord injury

A handy mnemonic to remember the general causes of incontinence is DRIP
Delirium (drugs, acute illness)
Retention (hypocontractility, outflow obstruction)
Inflammation/Infection/Impacted stool
Polyuria (drugs, high output)


  • Lifestyle: scheduled voiding, regulating fluid intake, kegel exercises
  • Medications to treat underlying cause (especially anti-cholinergics to treat urge incontinence as the detrusor responds to cholinergic stimulation)
  • Surgery: Such as¬†tension-free vaginal tape (sling) procedure (TVT) for treating stress urinary incontinence

Causes of Acute Kidney Injury (AKI)

Acute kidney injury can be caused by problems directly in the kidney, before the kidney or after the kidney. If you think about it that way, it’s much easier to develop a differentiate and establish a treatment.

The RIFLE criteria define the relative damage to the kidney and the outcome.
RIF = Severity in terms of serum creatinine (sCr), glomerular filtration rate (GFR) and urine production. Though for simplicity I only included serum creatinine since that is most likely what you’ll be looking at on initial blood work.
LE = Outcome variables (temporary or permanent)

Causes of hyponatremia

First – look to see what the person’s sodium is
Second – what is their volume status

The most important thing about hyponatremia is don’t correct more than 8 to 12 mmol/L per day!!!

Also, the paper titled “The Syndrome of Inappropriate Antidiuresis” by Ellison and Berl (N Engl J Med 2007;356:2064-72) is very useful.

Neural control of micturition

Nerve control of the bladder

  1. Sympathetic: hypogastric nerve (T10-L2), involuntary control of bladder neck and intrinsic sphincter
  2. Parasympathetic: pelvic nerve (S2-S4), involuntary contraction of detrusor
  3. Somatic: pudendal nerve (S2-S4), voluntary contraction/relaxation of external sphincter

Placenta Previa

Placenta previa isn’t generally something that is a concern in the western world, since prenatal ultrasounds are common practice, but in areas of the world where they’re not, it can be pretty devastating when the baby is being delivered.