1. Trials assessing pain during heel lance.
| Study | Design | Participants | Intervention | Outcome | Metrics Used | Results |
| Castral 2008 | Randomized controlled trial |
59 infants (31 intervention, 28 control) Postmenstrual age, mean, days: 248.3 (intervention), 254.4 (control) Birth weight, mean, grams: 1748.8 (intervention), 1846.2 (control) |
Intervention: 15 minutes of skin‐to‐skin care before, during and following heel lance Control: standard care during heel lance Provider: mother |
Neonatal Facial Coding System (NFCS) and heart rate at baseline, treatment, heel cleaning, heel lance, heel squeezing, wound compression, and recovery | Mean, mean difference (Treatment ‐control) Std. error, P value, 95% confidence intervals | Statistically significant differences between treatment and control groups during puncture, heel squeeze and post phases of heel lance. Infants receiving skin‐to‐skin contact more likely than infant controls to have significantly lower NFCS scores for heel lance (P = 0.023) and for heel squeeze. Both groups showed increased heart rate during puncture and heel squeeze although changes in these measures were less for treated infants (average increase of 19 bpm from baseline to heel puncture and squeezing in treatment group compared to average increase value of 23 bpm during puncture and 34 bpm during heel squeezing in control group) Means and standard deviations for NFCS scores and cry duration were obtained from the author |
| Cong 2009 | Randomized cross‐over | 14 infants (13 intervention, 10 control) Postnatal age, mean ± SD, days: 6 ± 1 (total) Postmenstural age, range, weeks:30‐32 Birth weight, mean ± SD, grams: 1775 ± 292 (total) Weight on day of study, mean ± SD, grams: 1706 ± 293 (total) |
Intervention: 60 minutes of skin‐to‐skin care before, during and following heel lance Control: standard care during heel lance Provider: mother |
Heart rate, low frequency (LF) and high frequency (HF) power, LF/HF power, and state at baseline, heel warming, heel lance, and recovery | Not reported | HR significantly lower in the KC condition (146 ± 9 bpm) than in IC (152 ± 13 bpm) during BL period (P < 0.05) and HS period (KC 159 ± bpm versus IC 165 ± 14 bpm, P < 0.05). HR increased significantly during HS from the BL and HW periods in both KC (P < 0.05) and IC conditions (P < 0.001), and returned to BL values during RC in both conditions. LF was higher in KC at BL (P < 0.01) and HS (P < 0.001) and HF was higher in KC at BL than in IC condition (P < 0.05). LF/HF ratio fluctuated less across periods in KC than in IC condition and was significantly lower during RC in KC than in IC (P < 0.001). LF and HF increased during HS from BL and HW, and dropped in the RC period in both KC (LF, P < 0.05 and HF, P < 0.01) and IC (LF, P < 0.01 and HF, P < 0.001) conditions. The LF/HF ratio was lower during HS than during BL, HW, and RC in both KC (P < 0.01) and IC (P < 0.001) conditions |
| Cong 2011 | Prospective randomized cross‐over | 28 infants: 14 infants ‐ 80 min SSC (Study 1); 10 infants ‐ 30 min SSC (Study 2) Postnatal age, mean ± SD, days: 5 ± 1 (Study 1); 6 ± 2 (Study 2) Postmenstrual age, range, weeks: 30‐32 Birth weight, mean ± SD, grams: 1779 ± 277 (Study 1); 1577 ± 327 (Study 2) |
Intervention: (a) Study 1: 60 minutes of skin‐to‐skin care before heel lance, with continued SSC during procedure, and followed by 20 minutes SSC post‐procedure; (b) Study 2: 10 minutes of skin‐to‐skin care before heel lance, with continued SSC during procedure, and followed by 20 minutes SSC post‐heel lance Control: standard care during heel lance Provider: mother |
PIPP score, salivary and serum cortisol at baseline, heel warming, heel lance and recovery | Mean, standard deviations | Study 2 showed lower PIPP scores at four time points during recovery (P < 0.05 to P < 0.001), lower salivary cortisol at the end of recovery (P < 0.05) and lower serum cortisol during heel lance for the kangaroo care heel lance condition (KCH) (P < 0.05) as swell as clinically lower PIPP scores in the KCH condition during heel lance |
| Cong 2012 | Randomized cross‐over | 26 preterm infants (PMA 28 0/7 to 32 6/7 weeks): 22 infants ‐ 30 min SSC (Study a); 25 infants ‐ 15 min SSC (Study b); 23 infants control Postnatal age, mean ± SD, days: 14.5 ± 6.3 (Study a); 13.8 ± 5.6 (Study b); 13.5 ± 5.6 (control) Birth weight, mean ± SD, grams: 1444.6 ± 379.0 |
Intervention: (a) Study a: 30 minutes of skin‐to‐skin care before and throughout heel lance (b) Study b: 15 minutes of skin‐to‐skin care before and throughout heel lance Control: standard care during heel lance Provider: mother |
Heart rate, heart rate variability (low frequency and high frequency power), LF/HF ratio, Infant behavioural state | Mean, standard deviations | HR changes from baseline to heel stick were significantly less in KC30 and KC15 than in IC, and more infants had HR decrease in IC than in 2 KC conditions. In IC, LF and HF significantly increased from baseline to heel stick and dropped from heel stick to recovery; in 2 KC conditions, no changes across study phases were found. During heel stick, LF and HF were significantly higher in IC than in KC30. In all 3 conditions, LF/HF ratio decreased from baseline to heel stick and increased to recovery; no differences were found between IC and two KC conditions. Both longer and shorter KC before and throughout heel stick can stabilize HR response in preterm infants, and longer KC significantly affected infants’ sympathetic and parasympathetic responses during heel stick compared with incubator care |
| Freire 2008 | Randomized controlled trial | 95 infants (31 intervention, 33 control, 31 comparison) Postmenstrual age, range, weeks: 28‐36 |
Intervention: 10 minutes of skin‐to‐skin care before, during heel lance Control: standard care during heel lance Comparison: Sweet taste 2 minutes before heel lance Provider: mother |
PIPP score | Mean, standard deviations | Heart rate variation and oxygen saturation significantly lower in kangaroo group compared to incubator and glucose groups (P = 0.0001 and P = 0.0012, respectively). Shorter duration of facial activity (brow bulge, eye squeeze and nasolabial furrowing) (P = 0.0001) and significantly lower PIPP score (P = 0.0001) observed in the kangaroo care method group Means and standard deviations for PIPP scores were obtained from the author |
| Gabriel 2013 | Randomized controlled trial | 136 infants (127 in analysis)(33/31 skin‐to‐skin, 33/32 sucrose, 35/35 sucrose + ssc, 35/29 skin‐to‐skin + breastfeeding) Gestational age, range, median, weeks: skin‐to‐skin: 37 to 41, 39; sucrose: 37 to 41, 39; sucrose + skin‐to‐skin: 37 to 41, 40; sucrose + breastfeeding: 37 to 42, 40 Birth weight, range, mean, grams: skin‐to‐skin: 2832 to 3900, 3359; sucrose: 1945 to 4176, 3215; sucrose + skin‐to‐skin: 2340 to 4108, 3349; sucrose + breastfeeding: 2266 to 4338, 3289 |
Group 1: 5 minutes of skin‐to‐skin care before, during heel lance. Group 2: 2 mL of 24% sucrose 2 minutes before heel lance Group 3: 5 minutes of skin‐to‐skin care before, during heel lance + 2 mL of 24% sucrose 2 minutes before heel lance Group 4: 5 minutes of breastfeeding with skin‐to‐skin before, during heel lance. Provider: skin‐to‐skin care and breastfeeding provided by the mother. Sucrose administered by a nurse. |
Crying time, % of crying in blood sampling, heart rate, NIPS | median and IQR (crying time, % of crying during blood sample, NIPS), mean and standard deviations (heart rate). | Breastfeeding + skin‐to‐skin group lower median NIPS score during heel stick (P < 0.01). NIPS scores in sucrose + skin‐to‐skin group lower than sucrose alone group 2 minutes after procedure (P = 0.02). Percentage of neonates with moderate‐to‐severe pain lowest in breastfeeding + skin‐to‐skin group, breastfeeding + skin‐to‐skin and sucrose + skin‐to‐skin had lower percentage of crying time compared to skin‐to‐skin alone. |
| Gao 2015 | Randomized controlled trial | 80 infants (75 in analysis) (40/38 in skin‐to‐skin, 40/37 in control) Gestational age, range, weeks: 27 to 37 Postnatal age, mean ± SD, days (heel stick 1,2,3,4): Skin‐to‐skin: 3.5 ± 0.3,4.3 ± 0.8,5.3 ± 0.6,6.7 ± 0.8 Control: 3.6 ± 0.4,4.2 ± 0.8,5.2 ± 0.7,6.8 ± 0.8 Birth weight, mean ± SD, grams: Intervention: 2017.8 ± 154.7; Control: 2030 ± 135.6 |
Intervention: Prone in incubator for 1 heel lance, Skin‐to‐skin 30 minutes pre‐heel lance for three consecutive procedures. Control: prone in incubator × 4 heel lances Provider: mother |
Crying time(seconds), grimacing time (seconds), heart rate | mean, standard deviations | Between group: Crying (P < 0.001), Grimacing (P < 0.001), HR (P < 0.001) significantly lower in skin‐to‐skin group. Within group: No loss in efficacy of skin‐to‐skin over time |
| Gray 2000 | Randomized controlled trial | 30 infants (15 control, 15 intervention) Postnatal age, range, hours: 33 to 55 Postmenstrual age, weeks: ≥ 37 Birth weight, mean (range), grams: 3300 (2600 to 3700) |
Intervention: 10 to 15 minutes of skin‐to‐skin care before heel lance Control: standard care during heel lance Provider: mother |
Heart rate during blood collection, cry duration and grimacing during recovery period | Mean | Infants held by mother in skin‐to‐skin contact, cried and grimaced for an average of 1 and 2 seconds, respectively, for entire recovery period. Control infants cried for a mean of 32 seconds and grimaced for a mean of 30 seconds of the 3‐minute recovery period (P < 0.001). Heart rate of skin‐to‐skin infants increased by about 8 to 10 bpm during blood collection whereas control infants heart rate rose by 36 to 38 bpm to an asymptote of 160bpm |
| Johnston 2003 | Randomized cross‐over | 74 infants Postnatal age, range, days: 0 to 10 Postmenstrual age, mean ± SD (range), weeks: 33.7 ± 1.1 (32.0 to 36.0) Birth weight, mean ± SD (range), grams: 2054 ± 406 (1320 to 3125) |
Intervention: 30 minutes of skin‐to‐skin care before and during heel lance Control: standard care during heel lance Provider: mother |
PIPP score at 30, 60, 90, and 120 minutes | Mean, 95% confidence interval |
Significantly lower PIPP scores in KC condition at 30 seconds (difference, 1.5 points; P = 0.04), 60 seconds (difference, 2.2 points; P = 0.002), and 90 seconds (difference, 0.6 point; P = 0.37) after heel‐lancing procedure. Heart rate and oxygen saturation similar in both conditions. Facial actions contributed significantly to total pain score (0.0 < P < 0.005), with facial actions averaging 20% greater in control versus KC condition Means and standard deviations for heart rate were obtained from the author |
| Johnston 2008 | Randomized cross‐over | 61 infants Postmenstrual age, mean ± SD, weeks: 30.5 ± 1 Birth weight, mean ± SD, grams: 1421 ± 490 |
Intervention: 15 minutes of skin‐to‐skin care before and during heel lance Comparison: swaddling in incubator 15 minutes before heel lance Provider: mother |
PIPP score at 30, 60, 90, and 120 minutes Time to return to baseline Heart rate |
Mean | Mean PIPP scores not significantly lower in KMC condition 30 and 60 seconds post‐heel lance Significant difference by 90 seconds post‐heel lance (KMC 8.871 (95% CI 7.85 to 9.89) versus Incubator 10.677 (95% CI 9.56to 11.79) P < 0.001). Insignificant difference continued to 120 seconds (8.86 (95% CI 7.48 to 10.26) versus 10.21 (95% CI 9.03to 11.39) P = 0.145). Significant difference in time returning to baseline heart rate at end of blood sampling (123 seconds (95% CI 103 to 142) for the KMC and 193 seconds for incubator (95% CI 158 to 227) (F (61,1) = 13.6, P < 0.0000). Facial actions significantly lower in KMC than incubator throughout phases. Maximum heart rate significantly lower at 30, 60 and 90 seconds. Minimum oxygen saturation levels significantly higher at 60 and 90 seconds Means and standard deviations for PIPP scores were obtained from the author |
| Johnston 2009 | Randomized cross‐over | 90 infants Postnatal age, range, days: 1 to 14 Postmenstrual age, mean ± SD, weeks: 33.4 ± 1.1 Birth weight, mean ± SD, grams: 1968 ± 388 |
Intervention: 30 minutes of skin‐to‐skin care before and during heel lance Comparison: 30 minutes of enhanced skin‐to‐skin care (rocking, singing/talking to baby, offering finger/pacifier for baby to suck Provider: mother |
PIPP score at 30, 60, 90, and 120 minutes | Mean | Mean PIPP scores not significantly different between conditions for any of the 30 s blocks of time. No difference in condition for examining time for heart rate to return to baseline Means and standard deviations for PIPP scores were obtained from the author |
| Johnston 2011 | Randomized cross‐over | 62 preterm infants (PMA 28 to 36 weeks) Postnatal age, mean, days: 5 to 10 Birth weight, mean ± SD, grams: 1565 ± 469 (father KC/mother KC); 1610 ± 494 (mother KC/father KC) |
Intervention: 30 minutes of skin‐to‐skin care before and during heel lance provided by mother Comparison: 30 minutes of skin‐to‐skin care before and during heel lance provided by father Provider: mother or father |
PIPP score at 30, 60, 90, and 120 minutes, time for HR to return to baseline | Mean difference, 95% confidence interval | Infants in maternal KC displayed significantly lower scores on the PIPP at 30 and 60 seconds after the heel lance than when in paternal KC (30 seconds mean difference 1.44 (95% CI 0.23 to 2.63); 60 seconds mean difference 1.55 (95% CI, 0.07 to 3.03). No differences at 90 and 120 seconds. The difference in time to return to KC heart rate before the heel lance was significant, with the time in maternal KC being 204 seconds and in paternal KC, 246 seconds (mean difference, 42 seconds (95% CI 5.16 to 81.06 seconds). |
| Johnston 2012 | Randomized cross‐over | 18 preterm infants (PMA 28 to 36 completed weeks) Postnatal age, range, days: within 10 days Birth weight, mean, grams: 2200 |
Intervention: 30 minutes of skin‐to‐skin care before and during heel stick provided by the mother Comparison: 30 minutes of skin‐to‐skin care before and during heel lance provided by an unrelated woman Provider: mother or an unrelated woman |
PIPP score at 30, 60, 90, and 120 minutes | Estimate of effect size (based Cohen’s formula, based on mean differences divided by the standard deviation) | The effect sizes on the pain scores (PIPP) were small, ranging from 1.1 to 1.7. The effect size at 30 sec was 0.23, at 60 sec was 0.24, at 90 sec was 0.43 and at 120 sec was 0.37 There was a 48% participation rate, with only 40 of 82 eligible cases having maternal consent. The main reason for refusal was discomfort with another woman providing kangaroo care |
| Kostandy 2008 | Randomized cross‐over | 10 infants Postmenstrual age, range, weeks: 30 to 32 Birth weight, mean ± SD, grams: 1577 ± 327.00 |
Intervention: 30 minutes of skin‐to‐skin care before and during heel lance Control: standard care during heel lance Provider: mother |
Cry duration at baseline, warming, heel lance, and recovery | Mean, standard deviation | Significant difference in crying time between study phases on both days (F (1,8) = 10.25, P < 0.001). When in KC as compared to the incubator, crying time was less during the heel lance (P = 0.001) and recovery (P = 0.01) phases |
| Liu 2015 | Randomized controlled trial | 40 infants Gestational age, mean ± SD, weeks: Intervention: 39.3 ± 0.94; Control: 39.36 ± 0.63 Birth weight, mean ± SD, grams: Intervention: 3337g ± 409.1; Control: 3740g ± 298.9 |
Intervention: Skin‐to‐skin care 15 minutes pre, during, and one minute after heel lance Control: Post bath, swaddled during and 1 min after heel lance. Provider: mother |
DAN score, crying time, pain facial expression duration, SpO2, HR | Mean, standard deviations | Decreased heart rate (P < 0.01), pain facial expression time (P = 0.041), crying time (P = 0.033), and DAN score (P < 0.01); increased oxygen saturation (P < 0.05) in skin‐to‐skin group. |
| Ludington‐Hoe 2005 | Randomized cross‐over | 23 preterm infants (< 37 weeks PMA) Postnatal age, mean ± SD, days: 22 ± 11.4 Postmenstrual age, mean ± SD, weeks: 31.4 ± 2.7 |
Intervention: 3 hours of skin‐to‐skin care before and during heel lance Control: standard care during heel lance Provider: mother |
Heart rate, respiratory rate, oxygen saturation, cry duration, behavioural state | Mean, standard deviation | Heart rate and length of crying in response to pain significantly reduced during KC and the KC heel lance as compared to when infants were in the warmer and had a heel lance in the warmer. Significant main effects were found for heart rate (F(1,32) = 3.54, P = 0.042) and cry length (F(1,32) = 5.20; P = 0.01). Mean rise in heart rate from baseline to heel lance was less in the KC condition than in the warmer condition (F(1, 32) = 3.01, P = 0.047). Crying length during KC heel lance significantly less than during warmer heel lance (F(1,32) = 7.38, P = 0.003) and post‐lance period (P = 0.02) |
| Mosayebi 2014 | Randomized Crossover | 64 preterm infants (GA range, mean, weeks ± SD = 30 to 36, 33 ± 1.95) Postnatal age, range, mean ± SD, days: 3 to 14, 7.28 ± 3.65 Birth weight range, mean ± SD: 1000 to 3500, 2095.85 ± 672.27 |
Intervention: 15 minutes of skin‐to‐skin care before, during, and two‐minutes post heel lance Control: 15 minutes prone and swaddled in an incubator before heel lance Provider: mother |
PIPP | mean, standard deviations | Mean score during and two minutes after intervention lower in skin‐to‐skin condition (P < 0.0) |
| Nimbalkar 2013 | Randomized cross‐over | 47 preterm infants (PMA 32 0/7 to 36 6/7 weeks) Postnatal age, mean, days: within 10 days Birth weight, mean, grams: 1730 (intervention), unclear (control) |
Intervention: 15 minutes of skin‐to‐skin care before, during, and 15 minutes after heel lance Control: standard care during heel lance Provider: mother |
PIPP score | Mean, standard deviation | Heart rate, behaviour and facial scores were statistically significant and lower in KMC group. But there was no statistically significant difference in oxygen saturation (SpO₂). The difference (4.85) in PIPP score was clinically and statistically significant (P < 0.001) |
| Okan 2010 | Prospective randomized controlled trial |
107 infants (35 treatment, 36 control, 36 comparison) Postnatal age, mean ± SD, days: 33.1± 5 Postmenstrual age, mean ± SD, days: 39.5 ± 0.6 |
Intervention: 15 min of skin‐to‐skin care before and during heel lance Control: standard care during heel lance Comparison: skin‐to‐skin care and breastfeeding before and during heel lance Provider: mother |
Crying time after painful stimulus Change in heart rate Change in SaO₂ NFCS |
Median, 25% to 75% IQR | Heart rate, oxygen saturation changes and length of crying were significantly reduced in treatment and comparison groups compared with control (P < 0.001). No difference found between treatment and comparison group Length of crying ‐ Intervention: 65 (50 to 133); Control: 184 (107 to 281); Comparison: 48 (40 to 98) Means and standard deviations for NFCS scores, heart rate and oxygen saturation were obtained from the author |
units: heart rate – beats/minute (bpm); crying time – seconds; postmensrutal age (PMA); Douleur Aigue Neonatal (DAN);Neonatal Facial Coding Scale (NFCS); Premature Infant Pain Profile (PIPP)